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  • 51.
    Luijten, Ineke H. N.
    et al.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Brooks, Katie
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Boulet, Nathalie
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Shabalina, Irina G.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Jaiprakash, Ankita
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Carlsson, Bo
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Fischer, Alexander W.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute. University Medical Center Hamburg Eppendor, Germany.
    Cannon, Barbara
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Nedergaard, Jan
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Glucocorticoid-Induced Obesity Develops Independently of UCP12019In: Cell Reports, E-ISSN 2211-1247, Vol. 27, no 6, p. 1686-1698Article in journal (Refereed)
    Abstract [en]

    An excess of glucocorticoids leads to the development of obesity in both mice and humans, but the mechanism for this is unknown. Here, we determine the extent to which decreased BAT thermogenic capacity (as a result of glucocorticoid treatment) contributes to the development of obesity. Contrary to previous suggestions, we show that only in mice housed at thermoneutrality (30 degrees C) does corticosterone treatment reduce total BAT UCP1 protein. This reduction is reflected in reduced brown adipocyte cellular and mitochondrial UCP1-dependent respiration. However, glucocorticoid-induced obesity develops to the same extent in animals housed at 21 degrees C and 30 degrees C, whereas total BAT UCP1 protein levels differ 100-fold between the two groups. In corticosterone-treated wild-type and UCP1 knockout mice housed at 30 degrees C, obesity also develops to the same extent. Thus, our results demonstrate that the development of glucocorticoid-induced obesity is not caused by a decreased UCP1-dependent thermogenic capacity.

  • 52.
    Luijten, Ineke H. N.
    et al.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Cannon, Barbara
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Nedergaard, Jan
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Glucocorticoids and Brown Adipose Tissue: Do glucocorticoids really inhibit thermogenesis?2019In: Molecular Aspects of Medicine, ISSN 0098-2997, E-ISSN 1872-9452, Vol. 68, p. 42-59Article, review/survey (Refereed)
    Abstract [en]

    A reduction in the thermogenic activity of brown adipose tissue (BAT) is presently discussed as a possible determinant for the development of obesity in humans. One group of endogenous factors that could potentially affect BAT activity is the glucocorticoids (e.g. cortisol). We analyse here studies examining the effects of alterations in glucocorticoid signaling on BAT recruitment and thermogenic capacity. We find that irrespective of which manipulation of glucocorticoid signaling is examined, a seemingly homogeneous picture of lowered thermogenic capacity due to glucocorticoid stimulation is apparently obtained: e.g. lowered uncoupling protein 1 (UCP1) protein levels per mg protein, and an increased lipid accumulation in BAT. However, further analyses generally indicate that these effects result from a dilution effect rather than a true decrease in total capacity; the tissue may thus be said to be in a state of pseudo-atrophy. However, under conditions of very low physiological stimulation of BAT, glucocorticoids may truly inhibit Ucp1 gene expression and consequently lower total UCP1 protein levels, but the metabolic effects of this reduction are probably minor. It is thus unlikely that glucocorticoids affect organismal metabolism and induce the development of obesity through alterations of BAT activity.

  • 53.
    Luijten, Ineke H. N.
    et al.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Feldmann, Helena M.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    von Essen, Gabriella
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Cannon, Barbara
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Nedergaard, Jan
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    In the absence of UCP1-mediated diet-induced thermogenesis, obesity is augmented even in the obesity-resistant 129S mouse strain2019In: American Journal of Physiology. Endocrinology and Metabolism, ISSN 0193-1849, E-ISSN 1522-1555, Vol. 316, no 5, p. E729-E740Article in journal (Refereed)
    Abstract [en]

    The attractive tenet that recruitment and activation of brown adipose tissue (BAT) and uncoupling protein 1 (UCP1) could counteract the development of obesity and its comorbidities in humans has been experimentally corroborated mainly by experiments demonstrating that UCP1-ablated mice on a C57B1/6 background (exempt from thermal stress) become more obese when fed a high-fat diet. However, concerns may be raised that this outcome of UCP1 ablation is restricted to this very special inbred and particularly obesity-prone mouse strain. Therefore, we have examined to which degree UCP1 ablation has similar metabolic effects in a mouse strain known to be obesity resistant: the 129S strain. For this, male 129S2/sv or 129SV/Pas mice and corresponding UCP1-knockout mice were fed chow or a high-fat or a cafeteria diet for 4 w.k. The absence of UCP1 augmented obesity (weight gain, body fat mass, %body fat, fat depot size) in high-fat diet- and cafeteria-fed mice, with a similar or lower food intake, indicating that, when present, UCP1 indeed decreases metabolic efficiency. The increased obesity was due to a decrease in energy expenditure. The consumption of a high-fat or cafeteria diet increased total BAT UCP1 protein levels in wild-type mice, and correspondingly. high-fat diet and cafeteria diet-fed mice demonstrated increased norepinephrine-induced oxygen consumption. There was a positive correlation between body fat and total BAT UCP1 protein content. No evidence for diet-induced adrenergic thermogenesis was found in UCP1-ablated mice. Thus, the obesity-reducing effect of UCP1 is not restricted to a particular, and perhaps not representative, mouse strain.

  • 54.
    Luijten, Ineke
    et al.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Jaiprakash, Ankita
    Hettinga, Laura
    Gao, Yun
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Cannon, Barbara
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Nedergaard, Jan
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Ucp1 transcription is regulated by glucocorticoid receptor binding at Ucp1 regulatory regionsManuscript (preprint) (Other academic)
    Abstract [en]

    Glucocorticoids suppress Ucp1gene expression in brown adipocytes (BA) and brite/beige adipocytes (WA) in a cell-autonomous manner. The intracellular mechanism through which this suppression is mediated is not known. In in vitrodifferentiated primary cultures of murine brown and brite pre-adipocytes, the presence of dexamethasone (DEX) significantly reduced adrenergically-induced Ucp1mRNA levels, but upregulated the expression of other adrenergically-regulated genes. Additionally, DEX treatment increased NE-induced cAMP accumulation in BA. We thus conclude that the glucocorticoid-induced downregulation of Ucp1transcription occurs independently of a glucocorticoid-induced upregulation of the adrenergic signaling pathway. Using chromatin immunoprecipitation in combination with DNA sequencing in brown adipose tissue isolated from C57Bl/6 and BALB/c mice, we identified 6 glucocorticoid receptor binding sites in Ucp1active enhancer regions marked by H3K27ac. Luciferase reporter gene assays in the BA WT1 cell line indicated that the liganded GR binds to a regulatory region 0-4 kb upstream of the Ucp1transcription start site and thereby suppresses transcription. Thus, our study has identified a direct regulation of Ucp1transcription by the glucocorticoid receptor that occurs independently of the effects of glucocorticoids on adrenergic signaling. 

  • 55. Madsen, Lise
    et al.
    Pedersen, Lone M
    Lillefosse, Haldis Haukaas
    Fjaere, Even
    Bronstad, Ingeborg
    Hao, Qin
    Petersen, Rasmus K
    Hallenborg, Philip
    Ma, Tao
    De Matteis, Rita
    Araujo, Pedro
    Mercader, Josep
    Bonet, M Luisa
    Hansen, Jacob B
    Cannon, Barbara
    Stockholm University, Faculty of Science, The Wenner-Gren Institute , Physiology.
    Nedergaard, Jan
    Stockholm University, Faculty of Science, The Wenner-Gren Institute , Physiology.
    Wang, Jun
    Cinti, Saverio
    Voshol, Peter
    Døskeland, Stein Ove
    Kristiansen, Karsten
    UCP1 induction during recruitment of brown adipocytes in white adipose tissue is dependent on cyclooxygenase activity.2010In: PloS one, ISSN 1932-6203, Vol. 5, no 6, p. e11391-Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: The uncoupling protein 1 (UCP1) is a hallmark of brown adipocytes and pivotal for cold- and diet-induced thermogenesis. METHODOLOGY/PRINCIPAL FINDINGS: Here we report that cyclooxygenase (COX) activity and prostaglandin E(2) (PGE(2)) are crucially involved in induction of UCP1 expression in inguinal white adipocytes, but not in classic interscapular brown adipocytes. Cold-induced expression of UCP1 in inguinal white adipocytes was repressed in COX2 knockout (KO) mice and by administration of the COX inhibitor indomethacin in wild-type mice. Indomethacin repressed beta-adrenergic induction of UCP1 expression in primary inguinal adipocytes. The use of PGE(2) receptor antagonists implicated EP(4) as a main PGE(2) receptor, and injection of the stable PGE(2) analog (EP(3/4) agonist) 16,16 dm PGE(2) induced UCP1 expression in inguinal white adipose tissue. Inhibition of COX activity attenuated diet-induced UCP1 expression and increased energy efficiency and adipose tissue mass in obesity-resistant mice kept at thermoneutrality. CONCLUSIONS/SIGNIFICANCE: Our findings provide evidence that induction of UCP1 expression in white adipose tissue, but not in classic interscapular brown adipose tissue is dependent on cyclooxygenase activity. Our results indicate that cyclooxygenase-dependent induction of UCP1 expression in white adipose tissues is important for diet-induced thermogenesis providing support for a surprising role of COX activity in the control of energy balance and obesity development.

  • 56.
    Mattsson, Charlotte L.
    et al.
    Stockholm University, Faculty of Science, The Wenner-Gren Institute .
    Csikasz, Robert I.
    Stockholm University, Faculty of Science, The Wenner-Gren Institute .
    Shabalina, Irina G.
    Stockholm University, Faculty of Science, The Wenner-Gren Institute .
    Nedergaard, Jan
    Stockholm University, Faculty of Science, The Wenner-Gren Institute .
    Cannon, Barbara
    Stockholm University, Faculty of Science, The Wenner-Gren Institute .
    Caveolin-1-ablated mice survive cold by nonshivering thermogenesis, despite desensitized adrenergic receptorsManuscript (preprint) (Other academic)
  • 57.
    Mattsson, Charlotte L
    et al.
    Stockholm University, Faculty of Science, The Wenner-Gren Institute , Physiology.
    Csikasz, Robert I
    Stockholm University, Faculty of Science, The Wenner-Gren Institute , Physiology.
    Shabalina, Irina G
    Stockholm University, Faculty of Science, The Wenner-Gren Institute , Physiology.
    Nedergaard, Jan
    Stockholm University, Faculty of Science, The Wenner-Gren Institute , Physiology.
    Cannon, Barbara
    Stockholm University, Faculty of Science, The Wenner-Gren Institute , Physiology.
    Caveolin-1-ablated mice survive in cold by nonshivering thermogenesis despite desensitized adrenergic responsiveness2010In: American Journal of Physiology. Endocrinology and Metabolism, ISSN 0193-1849, E-ISSN 1522-1555, Vol. 299, no 3, p. E374-83Article in journal (Refereed)
    Abstract [en]

    Caveolin-1 (Cav1)-ablated mice display impaired lipolysis in white adipose tissue. They also seem to have an impairment in brown adipose tissue function, implying that Cav1-ablated mice could encounter problems in surviving longer periods in cold temperatures. To investigate this, Cav1-ablated mice and wild-type mice were transferred to cold temperatures for extended periods of time, and parameters related to metabolism and thermogenesis were investigated. Unexpectedly, the Cav1-ablated mice survived in the cold. There were no differences between Cav1-ablated and wild-type mice with regard to food intake, in behavior related to shivering, or in body temperature. The Cav1-ablated mice had a halved total fat content independently of acclimation temperature. There was no difference in brown adipose tissue uncoupling protein-1 (UCP1) protein amount, and isolated brown fat mitochondria were thermogenically competent but displayed 30% higher thermogenic capacity. However, the beta(3)-adrenergic receptor amount was reduced by about one-third in the Cav1-ablated mice at all acclimation temperatures. Principally in accordance with this, a higher than standard dose of norepinephrine was needed to obtain full norepinephrine-induced thermogenesis in the Cav1-ablated mice; the higher dose was also needed for the Cav1-ablated mice to be able to utilize fat as a substrate for thermogenesis. In conclusion, the ablation of Cav1 impairs brown adipose tissue function by a desensitization of the adrenergic response; however, the desensitization is not evident in the animal as it is overcome physiologically, and Cav1-ablated mice can therefore survive in prolonged cold by nonshivering thermogenesis.

  • 58.
    Nabben, Miranda
    et al.
    Stockholm University, Faculty of Science, The Wenner-Gren Institute .
    Shabalina, Irina G.
    Stockholm University, Faculty of Science, The Wenner-Gren Institute .
    Moonen-Kornips, Esther
    van Beurden, Denis
    Cannon, Barbara
    Stockholm University, Faculty of Science, The Wenner-Gren Institute .
    Schrauwen, Patrick
    Nedergaard, Jan
    Stockholm University, Faculty of Science, The Wenner-Gren Institute .
    Hoeks, Joris
    Uncoupled respiration, ROS production, acute lipotoxicity and oxidative damage in isolated skeletal muscle mitochondria from UCP3-ablated mice2011In: Biochimica et Biophysica Acta - Bioenergetics, ISSN 0005-2728, E-ISSN 1879-2650, Vol. 1807, no 9, p. 1095-1105Article in journal (Refereed)
    Abstract [en]

    The function of uncoupling protein 3 (UCP3) is still not established. Mitochondrial uncoupling, control of ROS production, protection against lipotoxicity and protection against oxidative stress are functions classically discussed. To establish a role for UCP3 in these functions, we have here used UCP3 (-/-) mice, backcrossed for 10 generations on a C57Bl/6 background. In isolated skeletal muscle mitochondria, we examined uncoupled respiration, both unstimulated and in the presence of fatty acids. We did not observe any difference between mitochondria from wildtype and UCP3 (-/-) mice. We measured H(2)O(2) production rate and respiration rate under reactive oxygen species-generating conditions (succinate without rotenone) but found no effect of UCP3. We tested two models of acute lipotoxicity fatty add-induced oxidative inhibition and fatty acid-induced swelling-but did not observe any protective effect of UCP3. We examined oxidative stress by quantifying 4-hydroxynonenal protein adducts and protein carbonyls in the mitochondria-but did not observe any protective effect of UCP3. We conclude that under the experimental conditions tested here, we find no evidence for the function of UCP3 being basal or induced uncoupling, regulation of ROS production, protection against acute lipotoxicity or protection against oxidative damage.

  • 59.
    Nedergaard, Jan
    et al.
    Stockholm University, Faculty of Science, The Wenner-Gren Institute .
    Bengtsson, Tore
    Stockholm University, Faculty of Science, The Wenner-Gren Institute .
    Cannon, Barbara
    Stockholm University, Faculty of Science, The Wenner-Gren Institute .
    New Powers of Brown Fat: Fighting the Metabolic Syndrome2011In: Cell Metabolism, ISSN 1550-4131, E-ISSN 1932-7420, Vol. 13, no 3, p. 238-240Article in journal (Refereed)
    Abstract [en]

    An understanding of the full powers of brown adipose tissue (BAT) is only successively being accumulated. In a paper in Nature Medicine, Bartelt et al. (2011) add further impressive aspects to the potential powers of BAT in the combat against the metabolic syndrome by demonstrating its vast capacity for triglyceride clearance and glucose disposal.

  • 60.
    Nedergaard, Jan
    et al.
    Stockholm University, Faculty of Science, The Wenner-Gren Institute, Physiology.
    Bengtsson, Tore
    Stockholm University, Faculty of Science, The Wenner-Gren Institute, Physiology.
    Cannon, Barbara
    Stockholm University, Faculty of Science, The Wenner-Gren Institute, Physiology.
    Three years with adult human brown adipose tissue2010In: Annals of the New York Academy of Sciences, ISSN 0077-8923, E-ISSN 1749-6632, Vol. 1212, p. E20-E36Article in journal (Refereed)
    Abstract [en]

    The presence of active brown adipose tissue in adult humans has been recognized in general physiology only since 2007. The intervening three years established that the depots originally observed by (18)F-fluoro-deoxy-glucose positron emission tomography (FDG PET) scanning techniques really are brown adipose tissue depots because they are enriched for uncoupling protein 1 (UCP1). Reports of low apparent prevalence of brown adipose tissue based on retrospective studies of hospital records of FDG PET scans markedly underestimate true prevalence because such studies only reflect acute activity state; consequently, such retrospective studies cannot be conclusively analysed for factors influencing activity and amount of brown adipose tissue. Dedicated studies show that the true prevalence is 30-100%, depending on cohort. Warm temperature during the investigation-as well as adrenergic antagonists-inhibit tissue activity. There is probably no sexual dimorphism in the prevalence of brown adipose tissue. Outdoor temperature may affect the amount of brown adipose tissue, and the amount is negatively correlated with age and obesity. The presence of brown adipose tissue is associated with cold-induced nonshivering thermogenesis, and the tissue may be a major organ for glucose disposal. The decline in brown adipose tissue amount with increasing age may account for or aggravate middle-age obesity. Maintained activation of brown adipose tissue throughout life may thus protect against obesity and diabetes.

  • 61.
    Nedergaard, Jan
    et al.
    Stockholm University, Faculty of Science, The Wenner-Gren Institute .
    Cannon, Barbara
    Stockholm University, Faculty of Science, The Wenner-Gren Institute .
    Brown adipose tissue: development and function2011In: Fetal and neonatal physiology / [ed] Richard A Polin, William W Fox and Steven H Abman, Philadelphia, PA: Saunders Elsevier, 2011, 4th ed., p. 470-482Chapter in book (Refereed)
  • 62.
    Nedergaard, Jan
    et al.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Cannon, Barbara
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Diet-Induced Thermogenesis: Principles and Pitfalls2022In: Brown Adipose Tissue: Methods and Protocols / [ed] David A. Guertin, Christian Wolfrum, New York: Humana Press, 2022, p. 177-202Chapter in book (Refereed)
    Abstract [en]

    Concerning diet-induced thermogenesis, methodological issues relate mainly to the interpretation of measurements, rather than to the technical methodology as such. In the following, we point to a series of issues where the analysis often suggests the occurrence of UCP1-related diet-induced thermogenesis but where the observations are often the consequences of a process that has induced leanness rather than being the cause of them. We particularly emphasize the necessity of focusing on the total organism when interpreting biochemical and molecular data, where the concept of total tissue values rather than relative data better reflects physiologically important alterations. We stress the importance of performing experiments at thermoneutrality in order to obtain clinically relevant data and stress that true thermogenic agents may be overlooked if this is not done. 

  • 63.
    Nedergaard, Jan
    et al.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Cannon, Barbara
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    How brown is brown fat?: It depends where you look2013In: Nature Medicine, ISSN 1078-8956, E-ISSN 1546-170X, Vol. 19, no 5, p. 540-541Article in journal (Other academic)
    Abstract [en]

    Although it is now accepted that adult humans possess active brown adipose tissue, it has been questioned whether this is genuine classical brown adipose tissue. Two new studies provide evidence that humans, both as babies and adults, do have classical brown tissue and also indicate that there is heterogeneity in the composition of brown fat depots in humans, as in mice (

  • 64.
    Nedergaard, Jan
    et al.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Cannon, Barbara
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    The Browning of White Adipose Tissue: Some Burning Issues2014In: Cell Metabolism, ISSN 1550-4131, E-ISSN 1932-7420, Vol. 20, no 3, p. 396-407Article, review/survey (Refereed)
    Abstract [en]

    Igniting thermogenesis within white adipose tissue (i.e., promoting expression and activity of the uncoupling protein UCP1) has attracted much interest. Numerous browning agents'' have now been described (gene ablations, transgenes, foodcomponents, drugs, environments, etc.). The implied action of browning agents is that they increase UCP1 through this heat production, leading to slimming. Here, we particularly point to the possibility that cause and effect may on occasion be the reverse: browning agents may disrupt, for example, the fur, leading to increased heat loss, increased thermogenic demand to counteract this heat loss, and thus, through sympathetic nervous system activation, to enhanced UCP1 expression in white (and brown) adipose tissues.

  • 65.
    Nedergaard, Jan
    et al.
    Stockholm University, Faculty of Science, The Wenner-Gren Institute .
    Cannon, Barbara
    Stockholm University, Faculty of Science, The Wenner-Gren Institute .
    The changed metabolic world with human brown adipose tissue: therapeutic visions2010In: Cell metabolism, ISSN 1932-7420, Vol. 11, no 4, p. 268-272Article in journal (Refereed)
    Abstract [en]

    That adult humans possess active brown adipose tissue potentially leads to a paradigm shift in the understanding of human metabolism and of obesity. Adaptive adrenergic thermogenesis in humans represents brown adipose tissue activity, the absence of which may contribute to middle-age obesity.

  • 66.
    Nedergaard, Jan
    et al.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Cannon, Barbara
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    UCP1 mRNA does not produce heat2013In: Biochimica et Biophysica Acta - Molecular and Cell Biology of Lipids, ISSN 1388-1981, E-ISSN 1879-2618, Vol. 1831, no 5, p. 943-949Article in journal (Refereed)
    Abstract [en]

    Because of the possible role of brown adipose tissue and UCP1 in metabolic regulation, even in adult humans, there is presently considerable interest in quantifying, from in-vitro data, the thermogenic capacities of brown and brite/beige adipose tissues. An important issue is therefore to establish which parameters are the most adequate for this. A particularly important issue is the relevance of UCP1 mRNA levels as estimates of the degree of recruitment and of the thermogenic capacity resulting from differences in physiological conditions and from experimental manipulations. By solely following UCP1 mRNA levels in brown adipose tissue, the conclusion would be made that the tissue's highest activation occurs after only 6 h in the cold and then successively decreases to being only some 50% elevated after 1 month in the cold. However, measurement of total UCP1 protein levels per depot (mouse) reveals that the maximal thermogenic capacity estimated in this way is reached first after 1 month but represents an approx. 10-fold increase in thermogenic capacity. Since this in-vitro measure correlates quantitatively and temporally with the acquisition of nonshivering thermogenesis, this must be considered the most physiologically relevant parameter. Similarly, observations that cold acclimation barely increases UCP1 mRNA levels in classical brown adipose tissue but leads to a 200-fold increase in UCP1 mRNA levels in brite/beige adipose tissue depots may overemphasise the physiological significance of these depots, as the high fold-increases are due to very low initial levels, and the UCP1 mRNA levels reached are at least an order of magnitude lower than in brown adipose tissue; furthermore, based on total UCP1 protein amounts, the brite/beige depots attain only about 10% of the thermogenic capacity of the classical brown adipose tissue depots. Consequently, inadequate conclusions may be reached if UCP1 mRNA levels are used as a proxy for the metabolic significance of recruited versus non-recruited brown adipose tissue and for estimating the metabolic significance of brown versus brite/beige adipose tissues. This article is part of a Special Issue entitled Brown and White Fat: From Signaling to Disease.

  • 67.
    Nedergaard, Jan
    et al.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Fischer, Alexander W.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Cannon, Barbara
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Leptin as an Antitorpor Hormone: An Explanation for the Increased Metabolic Efficiency and Cold Sensitivity of ob/ob Mice?2023In: Physiological and Biochemical Zoology, ISSN 1522-2152, E-ISSN 1537-5293, Vol. 96, no 1, p. 30-39Article in journal (Refereed)
    Abstract [en]

    Leptin is recognized as an anorexigenic hormone. In its absence (e.g., in ob/ob mutant mice), mice become obese, primarily as a result of hyperphagia. A recurrent question is whether, additionally, leptin is thermogenic and thus also an antiobesity hormone in this way. We have earlier reviewed available data and have concluded that most articles implying a thermogenic effect of leptin have based this on a misconstrued division by body weight. Here, we have collected evidence that the remaining observations that imply that leptin is a thermogenic hormone are better understood as implying that leptin is an antitorpor hormone. Leptin levels increase in proportion to the body's energy reserves (i.e., stored lipids in the adipose tissue), and leptin thus serves as an indicator of energy availability. In the absence of leptin, ob/ob mice are exceedingly prone to enter daily torpor, since the absence of leptin causes them to perceive a lack of body energy reserves that, in combination with restricted or no food, induces them to enter the torpid state to save energy. This antitorpor effect of leptin probably explains the following earlier observations. First, ob/ob mice have the ability to gain weight even when pair fed with leptin-treated ob/ob mice. This is understood as follows: In the leptin-treated ob/ob mice, food intake is reduced. Untreated pair-fed mice enter daily torpor, and this markedly lowers total daily energy expenditure; the resulting surplus food energy is then accumulated as fat in these mice. However, ob/ob mice fed ad lib. do not enter torpor, so under normal conditions this mechanism does not contribute to the obesity found in the ob/ob mice. Second, neonatal ob/ob mice have the ability to become obese despite eating the same amount as wild-type mice: this is understood as these mice similarly entering daily torpor. Third, ob/ob mice on the C57BL/6J background have a lower metabolic rate: these mice were examined in the absence of food, and torpor was thus probably induced. Fourth, ob/ob mice have apparent high cold sensitivity: these mice experienced cold in the absence of food and would immediately enter deep torpor. It is suggested that this novel explanation of how the antitorpor effects of leptin affect mouse energy metabolism can open new avenues for leptin research.

  • 68.
    Nedergaard, Jan
    et al.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    von Essen, Gabriella
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Cannon, Barbara
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Brown adipose tissue: can it keep us slim? A discussion of the evidence for and against the existence of diet-induced thermogenesis in mice and men2023In: Philosophical Transactions of the Royal Society of London. Biological Sciences, ISSN 0962-8436, E-ISSN 1471-2970, Vol. 378, no 1888, article id 20220220Article, review/survey (Refereed)
    Abstract [en]

    The issue under discussion here is whether a decrease in the degree of UCP1 activity (and brown adipose tissue activity in general) could be a cause of obesity in humans. This possibility principally requires the existence of the phenomenon of diet-induced thermogenesis. Obesity could be a consequence of a reduced functionality of diet-induced thermogenesis. Experiments in mice indicate that diet-induced thermogenesis exists and is dependent on the presence of UCP1 and thus of brown adipose tissue activity. Accordingly, many (but not all) experiments indicate that in the absence of UCP1, mice become obese. Whether similar mechanisms exist in humans is still unknown. A series of studies have indicated a correlation between obesity and low brown adipose tissue activity, but it may be so that the obesity itself may influence the estimates of brown adipose tissue activity (generally glucose uptake), partly explaining the relationship. Estimates of brown adipose tissue catabolizing activity would seem to indicate that it may possess a capacity sufficient to help maintain body weight, and obesity would thus be aggravated in its absence.

  • 69.
    Nedergaard, Jan
    et al.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Wang, Yanling
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Cannon, Barbara
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Cell proliferation and apoptosis inhibition: essential processes for recruitment of the full thermogenic capacity-of-brown-adipose-tissue2019In: Biochimica et Biophysica Acta - Molecular and Cell Biology of Lipids, ISSN 1388-1981, E-ISSN 1879-2618, Vol. 1864, no 1, p. 51-58Article, review/survey (Refereed)
    Abstract [en]

    In mice living under normal animal house conditions, the brown adipocytes in classical brown adipose tissue depots are already essentially fully differentiated: UCP1 mRNA and UCP1 protein levels are practically saturated. This means that any further recruitment in response to cold exposure or any other browning agent - does not result in significant augmentation of these parameters. This may easily be construed to indicate that classical brown adipose tissue cannot be further recruited. However, this is far from the case: the capacity for further recruitment instead lies in the ability of the tissue to increase the number of brown-fat cells, a remarkable and highly controlled physiological recruitment process. We have compiled here the available data concerning the unique ability of norepinephrine to increase cell proliferation and inhibit apoptosis in brown adipocytes. Adrenergically stimulated cell proliferation is fully mediated via beta(1)-adrenoceptors and occurs through activation of stem cells in the tissue; intracellular mediation of the signal involves CAMP and protein kinase A activation, but activation of Erk1/2 is not part of the pathway. Apoptosis inhibition in brown adipocytes is induced by both beta- and alpha(1)-adrenergic receptors and here the intracellular pathway includes Erk1/2 activation. This unique ability of norepinephrine to increase cell number in an apparently mitogenically dormant tissue provides possibilities to augment the metabolic capacity of brown adipose tissue, also for therapeutic purposes.

  • 70.
    Otton, Rosemari
    et al.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute. Cruzeiro do Sul University, Brazil.
    Petrovic, Natasa
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Cannon, Barbara
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Nedergaard, Jan
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    On the Validity of Adipogenic Cell Lines as Model Systems for Browning Processes: In Authentic Brown, Brite/Beige, and White Preadipocytes, There is No Cell-Autonomous Thermogenic Recruitment by Green Tea Compounds2021In: Frontiers in Nutrition, E-ISSN 2296-861X, Vol. 8, article id 715859Article in journal (Refereed)
    Abstract [en]

    The potential ability of nutritional compounds to induce or enhance the browning of adipocytes has attracted large interest as a workable means of combatting the obesity epidemic. Green tea compounds are discussed as such inducers of an enhanced thermogenic capacity and activity. However, the cell-autonomous effects of green tea compounds on adipocytes have until now only been demonstrated in adipogenic cell lines (3T3-L1 and 3T3-F442A), i.e., cells of undefined tissue lineage. In this study, we examine the ability of green tea compounds to cell-autonomously induce thermogenic recruitment in authentic brown and brite/beige adipocytes in vitro. In primary brown adipocytes, the green tea compounds suppressed basal UCP1 gene expression, and there was no positive interaction between the compounds and adrenergic stimulation. In white adipocytes, green tea compounds decreased both basal and norepinephrine-induced UCP1 mRNA levels, and this was associated with the suppression of cell differentiation, indicated by reduced lipogenic gene expression and lipid accumulation. A lack of interaction between rosiglitazone and green tea compounds suggests that the green tea compounds do not directly interact with the PPARγ pathway. We conclude that there is a negative effect of the green tea compounds on basal UCP1 gene expression, in both brown and white primary adipocytes, in contrast to the positive effects earlier reported from studies in adipogenic cell lines. We posit that the epigenetic status of the adipogenic cell lines is fundamentally different from that of genuine brown and white adipocytes, reflected, e.g., in several-thousand-fold differences in UCP1 gene expression levels. Thus, results obtained with adipogenic cell lines cannot unreservedly be extrapolated as being relevant for authentic effects in brown and white adipocytes. We suggest that this conclusion can be of general concern for studies attempting to establish physiologically relevant cell-autonomous effects.

  • 71.
    Petrovic, Natasa
    et al.
    Stockholm University, Faculty of Science, The Wenner-Gren Institute , Physiology.
    Walden, Tomas B
    Stockholm University, Faculty of Science, The Wenner-Gren Institute , Physiology.
    Shabalina, Irina G
    Stockholm University, Faculty of Science, The Wenner-Gren Institute , Physiology.
    Timmons, James A
    Cannon, Barbara
    Stockholm University, Faculty of Science, The Wenner-Gren Institute , Physiology.
    Nedergaard, Jan
    Stockholm University, Faculty of Science, The Wenner-Gren Institute , Physiology.
    Chronic Perixosome Proliferator-activated Receptor gamma (PPARgamma) activation of epididymally derived white adipocyte cultures reveals a population of thermogenically competent, UCP1-containing adipocytes molecularly distinct from classical brown adipocytes.2010In: Journal of Biological Chemistry, ISSN 0021-9258, E-ISSN 1083-351X, Vol. 285, no 10, p. 7153-7164Article in journal (Refereed)
    Abstract [en]

    The recent insight that brown adipocytes and muscle cells share a common origin and in this respect are distinct from white adipocytes has spurred questions concerning the origin and molecular characteristics of the UCP1-expressing cells observed in classical white adipose tissue depots under certain physiological or pharmacological conditions. Examining precursors from the purest white adipose tissue depot (epididymal), we report here that chronic treatment with the PPARgamma agonist rosiglitazone promotes not only the expression of PGC-1alpha and mitochondriogenesis in these cells but also a norepinephrine-augmentable UCP1 gene expression in a significant subset of the cells, providing these cells with a genuine thermogenic capacity. However, although functional thermogenic genes are expressed, the cells are devoid of transcripts for the novel transcription factors now associated with classical brown adipocytes (Zic1, Lhx8, Meox2 and characteristically PRDM16) or for myocyte-associated genes (myogenin and myomirs (muscle-specific microRNAs)) and retain white-fat characteristics such as Hoxc9 expression. Co-culture experiments verify that the UCP1-expressing cells are not proliferating classical brown adipocytes (adipomyocytes) and these cells therefore constitute a subset of adipocytes (''brite'' adipocytes) with a developmental origin and molecular characteristics distinguishing them as a separate class of cells.

  • 72. Rohm, Maria
    et al.
    Schäfer, Michaela
    Laurent, Victor
    Üstünel, Bilgen Ekim
    Niopek, Katharina
    Algire, Carolyn
    Hautzinger, Oksana
    Sijmonsma, Tjeerd P.
    Zota, Annika
    Medrikova, Dasa
    Pellegata, Natalia S.
    Ryden, Mikael
    Kulyte, Agné
    Dahlman, Ingrid
    Arner, Peter
    Petrovic, Natasa
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Cannon, Barbara
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Amri, Ez-Zoubir
    Kemp, Bruce E.
    Steinberg, Gregory R.
    Janovska, Petra
    Kopecky, Jan
    Wolfrum, Christian
    Blüher, Matthias
    Diaz, Mauricio Berriel
    Herzig, Stephan
    An AMP-activated protein kinase-stabilizing peptide ameliorates adipose tissue wasting in cancer cachexia in mice2016In: Nature Medicine, ISSN 1078-8956, E-ISSN 1546-170X, Vol. 22, no 10, p. 1120-1130Article in journal (Refereed)
    Abstract [en]

    Cachexia represents a fatal energy-wasting syndrome in a large number of patients with cancer that mostly results in a pathological loss of skeletal muscle and adipose tissue. Here we show that tumor cell exposure and tumor growth in mice triggered a futile energy-wasting cycle in cultured white adipocytes and white adipose tissue (WAT), respectively. Although uncoupling protein 1 (Ucp1)-dependent thermogenesis was dispensable for tumor-induced body wasting, WAT from cachectic mice and tumor-cell-supernatant-treated adipocytes were consistently characterized by the simultaneous induction of both lipolytic and lipogenic pathways. Paradoxically, this was accompanied by an inactivated AMP-activated protein kinase (Ampk), which is normally activated in peripheral tissues during states of low cellular energy. Ampk inactivation correlated with its degradation and with upregulation of the Ampk-interacting protein Cidea. Therefore, we developed an Ampk-stabilizing peptide, ACIP, which was able to ameliorate WAT wasting in vitro and in vivo by shielding the Cidea-targeted interaction surface on Ampk. Thus, our data establish the Ucp1-independent remodeling of adipocyte lipid homeostasis as a key event in tumor-induced WAT wasting, and we propose the ACIP-dependent preservation of Ampk integrity in the WAT as a concept in future therapies for cachexia.

  • 73.
    Shabalina, Irina
    et al.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Edgar, Daniel
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Gibanova, Natalia
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Kalinovich, Anastasia
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Petrovic, Natasa
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Vyssokikh, Mikhail Yu.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Cannon, Barbara
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Nedergaard, Jan
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Enhanced ROS Production in Mitochondria from Prematurely Aging mtDNA Mutator Mice2024In: Biochemistry (Moscow), ISSN 0006-2979, E-ISSN 1608-3040, Vol. 89, no 2, p. 279-298Article in journal (Refereed)
    Abstract [en]

    An increase in mitochondrial DNA (mtDNA) mutations and an ensuing increase in mitochondrial reactive oxygen species (ROS) production have been suggested to be a cause of the aging process (the mitochondrial hypothesis of aging). In agreement with this, mtDNA-mutator mice accumulate a large amount of mtDNA mutations, giving rise to defective mitochondria and an accelerated aging phenotype. However, incongruously, the rates of ROS production in mtDNA mutator mitochondria have generally earlier been reported to be lower - not higher - than in wildtype, thus apparently invalidating the mitochondrial hypothesis of aging. We have here re-examined ROS production rates in mtDNA-mutator mice mitochondria. Using traditional conditions for measuring ROS (succinate in the absence of rotenone), we indeed found lower ROS in the mtDNA-mutator mitochondria compared to wildtype. This ROS mainly results from reverse electron flow driven by the membrane potential, but the membrane potential reached in the isolated mtDNA-mutator mitochondria was 33 mV lower than that in wildtype mitochondria, due to the feedback inhibition of succinate oxidation by oxaloacetate, and to a lower oxidative capacity in the mtDNA-mutator mice, explaining the lower ROS production. In contrast, in normal forward electron flow systems (pyruvate (or glutamate) + malate or palmitoyl-CoA + carnitine), mitochondrial ROS production was higher in the mtDNA-mutator mitochondria. Particularly, even during active oxidative phosphorylation (as would be ongoing physiologically), higher ROS rates were seen in the mtDNA-mutator mitochondria than in wildtype. Thus, when examined under physiological conditions, mitochondrial ROS production rates are indeed increased in mtDNA-mutator mitochondria. While this does not prove the validity of the mitochondrial hypothesis of aging, it may no longer be said to be negated in this respect. This paper is dedicated to the memory of Professor Vladimir P. Skulachev.

  • 74.
    Shabalina, Irina G
    et al.
    Stockholm University, Faculty of Science, The Wenner-Gren Institute , Physiology.
    Hoeks, Joris
    Kramarova, Tatiana V
    Schrauwen, Patrick
    Cannon, Barbara
    Stockholm University, Faculty of Science, The Wenner-Gren Institute , Physiology.
    Nedergaard, Jan
    Stockholm University, Faculty of Science, The Wenner-Gren Institute , Physiology.
    Cold tolerance of UCP1-ablated mice: A skeletal muscle mitochondria switch toward lipid oxidation with marked UCP3 up-regulation not associated with increased basal, fatty acid- or ROS-induced uncoupling or enhanced GDP effects.2010In: Biochimica et Biophysica Acta, ISSN 0006-3002, E-ISSN 1878-2434, Vol. 1797, no 6-7, p. 968-80Article in journal (Refereed)
    Abstract [en]

    Mice lacking the thermogenic mitochondrial membrane protein UCP1 (uncoupling protein 1) - and thus all heat production from brown adipose tissue - can still adapt to a cold environment (4 degrees C) if successively transferred to the cold. The mechanism behind this adaptation has not been clarified. To examine possible adaptive processes in the skeletal muscle, we isolated mitochondria from the hind limb muscles of cold-acclimated wild-type and UCP1(-/-) mice and examined their bioenergetic chracteristics. We observed a switch in metabolism, from carbohydrate towards lipid catabolism, and an increased total mitochondrial complement, with an increased total ATP production capacity. The UCP1(-/-) muscle mitochondria did not display a changed state-4 respiration rate (no uncoupling) and were less sensitive to the uncoupling effect of fatty acids than the wild-type mitochondria. The content of UCP3 was increased 3-4 fold, but despite this, endogenous superoxide could not invoke a higher proton leak, and the small inhibitory effect of GDP was unaltered, indicating that it was not mediated by UCP3. Double mutant mice (UCP1(-/-) plus superoxide dismutase 2-overexpression) were not more cold sensitive than UCP1(-/-), bringing into question an involvement of reactive oxygen species (ROS) in activation of any alternative thermogenic mechanism. We conclude that there is no evidence for an involvement of UCP3 in basal, fatty-acid- or superoxide-stimulated oxygen consumption or in GDP sensitivity. The adaptations observed did not imply any direct alternative process for nonshivering thermogenesis but the adaptations observed would be congruent with adaptation to chronically enhanced muscle activity caused by incessant shivering in these mice.

  • 75.
    Shabalina, Irina G.
    et al.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Kalinovich, Anastasia V.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Cannon, Barbara
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Nedergaard, Jan
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Metabolically inert perfluorinated fatty acids directly activate uncoupling protein 1 in brown-fat mitochondria2016In: Archives of Toxicology, ISSN 0340-5761, E-ISSN 1432-0738, Vol. 90, no 5, p. 1117-1128Article in journal (Refereed)
    Abstract [en]

    The metabolically inert perfluorinated fatty acids perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) can display fatty acid-like activity in biological systems. The uncoupling protein 1 (UCP1) in brown adipose tissue is physiologically (re)activated by fatty acids, including octanoate. This leads to bioenergetically uncoupled energy dissipation (heat production, thermogenesis). We have examined here the possibility that PFOA/PFOS can directly (re)activate UCP1 in isolated mouse brown-fat mitochondria. In wild-type brown-fat mitochondria, PFOS and PFOA overcame GDP-inhibited thermogenesis, leading to increased oxygen consumption and dissipated membrane potential. The absence of this effect in brown-fat mitochondria from UCP1-ablated mice indicated that it occurred through activation of UCP1. A competitive type of inhibition by increased GDP concentrations indicated interaction with the same mechanistic site as that utilized by fatty acids. No effect was observed in heart mitochondria, i.e., in mitochondria without UCP1. The stimulatory effect of PFOA/PFOS was not secondary to non-specific mitochondrial membrane permeabilization or to ROS production. Thus, metabolic effects of perfluorinated fatty acids could include direct brown adipose tissue (UCP1) activation. The possibility that this may lead to unwarranted extra heat production and thus extra utilization of food resources, leading to decreased fitness in mammalian wildlife, is discussed, as well as possible negative effects in humans. However, a possibility to utilize PFOA-/PFOS-like substances for activating UCP1 therapeutically in obesity-prone humans may also be envisaged.

  • 76.
    Shabalina, Irina G.
    et al.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Kramarova, Tatiana V.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Mattsson, Charlotte L.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Petrovic, Natasa
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Qazi, Mousumi Rahman
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Csikasz, Robert I.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Chang, Shu-Ching
    Butenhoff, John
    DePierre, Joseph W.
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Cannon, Barbara
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Nedergaard, Jan
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    The Environmental Pollutants Perfluorooctane Sulfonate and Perfluorooctanoic Acid Upregulate Uncoupling Protein 1 (UCP1) in Brown-Fat Mitochondria Through a UCP1-Dependent Reduction in Food Intake2015In: Toxicological Sciences, ISSN 1096-6080, E-ISSN 1096-0929, Vol. 146, no 2, p. 334-343Article in journal (Refereed)
    Abstract [en]

    The environmental pollutants perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) cause a dramatic reduction in the size of the major adipose tissue depots and a general body weight decrease when they are added to the food of mice. We demonstrate here that this is mainly due to a reduction in food intake; this reduction was not due to food aversion. Remarkably and unexpectedly, a large part of the effect of PFOA/PFOS on food intake was dependent on the presence of the uncoupling protein 1 (UCP1) in the mice. Correspondingly, PFOA/PFOS treatment induced recruitment of brown adipose tissue mitochondria: increased oxidative capacity and increased UCP1-mediated oxygen consumption (thermogenesis). In mice pair-fed to the food intake during PFOA/PFOS treatment in wildtype mice, brown-fat mitochondrial recruitment was also induced. We conclude that we have uncovered the existence of a regulatory component of food intake that is dependent upon brown adipose tissue thermogenic activity. The possible environmental consequences of this novel PFOA/PFOS effect (a possible decreased fitness) are noted, as well as the perspectives of this finding on the general understanding of control of food intake control and its possible extension to combatting obesity.

  • 77.
    Shabalina, Irina G
    et al.
    Stockholm University, Faculty of Science, The Wenner-Gren Institute , Physiology.
    Ost, Mario
    Petrovic, Natasa
    Stockholm University, Faculty of Science, The Wenner-Gren Institute , Physiology.
    Vrbacky, Marek
    Nedergaard, Jan
    Stockholm University, Faculty of Science, The Wenner-Gren Institute , Physiology.
    Cannon, Barbara
    Stockholm University, Faculty of Science, The Wenner-Gren Institute , Physiology.
    Uncoupling protein-1 is not leaky.2010In: Biochimica et Biophysica Acta, ISSN 0006-3002, E-ISSN 1878-2434, Vol. 1797, no 6-7, p. 773-84Article in journal (Refereed)
    Abstract [en]

    The activity of uncoupling protein-1 (UCP1) is rate-limiting for nonshivering thermogenesis and diet-induced thermogenesis. Characteristically, this activity is inhibited by GDP experimentally and presumably mainly by cytosolic ATP within brown-fat cells. The issue as to whether UCP1 has a residual proton conductance even when fully saturated with GDP/ATP (as has recently been suggested) has not only scientific but also applied interest, since a residual proton conductance would make overexpressed UCP1 weight-reducing even without physiological/pharmacological activation. To examine this question, we have here established optimal conditions for studying the bioenergetics of wild-type and UCP1(-/-) brown-fat mitochondria, analysing UCP1-mediated differences in parallel preparations of brown-fat mitochondria from both genotypes. Comparing different substrates, we find that pyruvate (or palmitoyl-l-carnitine) shows the largest relative coupling by GDP. Comparing albumin concentrations, we find the range 0.1-0.6% optimal; higher concentrations are inhibitory. Comparing basic medium composition, we find 125mM sucrose optimal; an ionic medium (50-100mM KCl) functions for wild-type but is detrimental for UCP1(-/-) mitochondria. Using optimal conditions, we find no evidence for a residual proton conductance (not a higher post-GDP respiration, a lower membrane potential or an altered proton leak at highest common potential) with either pyruvate or glycerol-3-phosphate as substrates, nor by a 3-4-fold alteration of the amount of UCP1. We could demonstrate that certain experimental conditions, due to respiratoty inhibition, could lead to the suggestion that UCP1 possesses a residual proton conductance but find that under optimal conditions our experiments concur with implications from physiological observations that in the presence of inhibitory nucleotides, UCP1 is not leaky.

  • 78.
    Shabalina, Irina G.
    et al.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Petrovic, Natasa
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    de Jong, Jasper M. A.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Kalinovich, Anastasia
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Cannon, Barbara
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Nedergaard, Jan
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    UCP1 in Brite/Beige Adipose Tissue Mitochondria Is Functionally Thermogenic2013In: Cell Reports, E-ISSN 2211-1247, Vol. 5, no 5, p. 1196-1203Article in journal (Refereed)
    Abstract [en]

    The phenomenon of white fat browning, in which certain white adipose tissue depots significantly increase gene expression for the uncoupling protein UCP1 and thus supposedly acquire thermogenic, fat-burning properties, has attracted considerable attention. Because the mRNA increases are from very low initial levels, the metabolic relevance of the change is unclear: is the UCP1 protein thermogenically competent in these brite/beige-fat mitochondria? We found that, in mitochondria isolated from the inguinal white adipose depot of cold-acclimated mice, UCP1 protein levels almost reached those in brown-fat mitochondria. The UCP1 was thermogenically functional, in that these mitochondria exhibited UCP1-dependent thermogenesis with lipid or carbohydrate substrates with canonical guanosine diphosphate (GDP) sensitivity and loss of thermogenesis in UCP1 knockout (KO) mice. Obesogenic mouse strains had a lower thermogenic potential than obesity-resistant strains. The thermogenic density (UCP1-dependent oxygen consumption per g tissue) of inguinal white adipose tissue was maximally one-fifth of interscapular brown adipose tissue, and the total quantitative contribution of all inguinal mitochondria was maximally one-third of all interscapular brown-fat mitochondria, indicating that the classical brown adipose tissue depots would still predominate in thermogenesis.

  • 79.
    Shabalina, Irina G.
    et al.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Vrbacky, Marek
    Pecinova, Alena
    Kalinovich, Anastasia V.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Drahota, Zdenek
    Houstek, Josef
    Mracek, Tomas
    Cannon, Barbara
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Nedergaard, Jan
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    ROS production in brown adipose tissue mitochondria: The question of UCP1-dependence2014In: Biochimica et Biophysica Acta - Bioenergetics, ISSN 0005-2728, E-ISSN 1879-2650, Vol. 1837, no 12, p. 2017-2030Article in journal (Refereed)
    Abstract [en]

    Whether active UCP1 can reduce ROS production in brown-fat mitochondria is presently not settled. The issue is of principal significance, as it can be seen as a proof- or disproof-of-principle concerning the ability of any protein to diminish ROS production through membrane depolarization. We therefore undertook a comprehensive investigation of the significance of UCP1 for ROS production, by comparing the ROS production in brown-fat mitochondria isolated from wildtype mice (that display membrane depolarization) or from UCP1(-/-) mice (with a high membrane potential). We tested the significance of UCP1 for glycerol-3-phosphate-supported ROS production by three methods (fluorescent dihydroethidium and the ESR probe PHH for superoxide, and fluorescent Amplex Red for hydrogen peroxide), and followed ROS production also with succinate, acyl-CoA or pyruvate as substrate. We studied the effects of the reverse electron flow inhibitor rotenone, the UCP1 activity inhibitor GDP, and the uncoupler FCCP. We also examined the effect of a physiologically induced increase in UCP1 amount. We noted GDP effects that were not UCP1-related. We conclude that only ROS production supported by exogenously added succinate was affected by the presence of active UCP1; ROS production supported by any other tested substrate (including endogenously generated succinate) was unaffected. This conclusion indicates that UCP1 is not involved in control of ROS production in brown-fat mitochondria. Extrapolation of these data to other tissues would imply that membrane depolarization may not necessarily decrease physiologically relevant ROS production.

  • 80.
    Shabalina, Irina G.
    et al.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Vyssokikh, Mikhail Yu.
    Gibanova, Natalia
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Csikasz, Robert I.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Edgar, Daniel
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Hallden-Waldemarson, Anne
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Rozhdestvenskaya, Zinaida
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Bakeeva, Lora E.
    Vays, Valeria B.
    Pustovidko, Antonina V.
    Skulachev, Maxim V.
    Cannon, Barbara
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Skulachev, Vladimir P.
    Nedergaard, Jan
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Improved health-span and lifespan in mtDNA mutator mice treated with the mitochondrially targeted antioxidant SkQ12017In: Aging, ISSN 1945-4589, E-ISSN 1945-4589, Vol. 9, no 2, p. 315-339Article in journal (Refereed)
    Abstract [en]

    MtDNA mutator mice exhibit marked features of premature aging. We find that these mice treated from age of approximate to 100 days with the mitochondria-targeted antioxidant SkQ1 showed a delayed appearance of traits of aging such as kyphosis, alopecia, lowering of body temperature, body weight loss, as well as ameliorated heart, kidney and liver pathologies. These effects of SkQ1 are suggested to be related to an alleviation of the effects of an enhanced reactive oxygen species (ROS) level in mtDNA mutator mice: the increased mitochondrial ROS released due to mitochondrial mutations probably interact with polyunsaturated fatty acids in cardiolipin, releasing malondialdehyde and 4-hydroxynonenal that form protein adducts and thus diminishes mitochondrial functions. SkQ1 counteracts this as it scavenges mitochondrial ROS. As the results, the normal mitochondrial ultrastructure is preserved in liver and heart; the phosphorylation capacity of skeletal muscle mitochondria as well as the thermogenic capacity of brown adipose tissue is also improved. The SkQ1-treated mice live significantly longer (335 versus 290 days). These data may be relevant in relation to treatment of mitochondrial diseases particularly and the process of aging in general.

  • 81. Timmons, James A
    et al.
    Wennmalm, Kristian
    Larsson, Ola
    Walden, Tomas B
    Stockholm University, Faculty of Science, The Wenner-Gren Institute .
    Lassmann, Timo
    Petrovic, Natasa
    Stockholm University, Faculty of Science, The Wenner-Gren Institute .
    Hamilton, D Lee
    Gimeno, Ruth E
    Wahlestedt, Claes
    Baar, Keith
    Nedergaard, Jan
    Stockholm University, Faculty of Science, The Wenner-Gren Institute .
    Cannon, Barbara
    Stockholm University, Faculty of Science, The Wenner-Gren Institute .
    Myogenic gene expression signature establishes that brown and white adipocytes originate from distinct cell lineages.2007In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 104, no 11, p. 4401-4406Article in journal (Refereed)
    Abstract [en]

    Attainment of a brown adipocyte cell phenotype in white adipocytes, with their abundant mitochondria and increased energy expenditure potential, is a legitimate strategy for combating obesity. The unique transcriptional regulators of the primary brown adipocyte phenotype are unknown, limiting our ability to promote brown adipogenesis over white. In the present work, we used microarray analysis strategies to study primary preadipocytes, and we made the striking discovery that brown preadipocytes demonstrate a myogenic transcriptional signature, whereas both brown and white primary preadipocytes demonstrate signatures distinct from those found in immortalized adipogenic models. We found a plausible SIRT1-related transcriptional signature during brown adipocyte differentiation that may contribute to silencing the myogenic signature. In contrast to brown preadipocytes or skeletal muscle cells, white preadipocytes express Tcf21, a transcription factor that has been shown to suppress myogenesis and nuclear receptor activity. In addition, we identified a number of developmental genes that are differentially expressed between brown and white preadipocytes and that have recently been implicated in human obesity. The interlinkage between the myocyte and the brown preadipocyte confirms the distinct origin for brown versus white adipose tissue and also represents a plausible explanation as to why brown adipocytes ultimately specialize in lipid catabolism rather than storage, much like oxidative skeletal muscle tissue.

  • 82. Virtue, Sam
    et al.
    Feldmann, Helena
    Stockholm University, Faculty of Science, The Wenner-Gren Institute , Physiology.
    Christian, Mark
    Tan, Chong Yew
    Masoodi, Mojgan
    Dale, Martin
    Lelliott, Chris
    Burling, Keith
    Campbell, Mark
    Eguchi, Naomi
    Voshol, Peter
    Sethi, Jaswinder K.
    Parker, Malcolm
    Urade, Yoshihiro
    Griffin, Julian L.
    Cannon, Barbara
    Stockholm University, Faculty of Science, The Wenner-Gren Institute , Physiology.
    Vidal-Puig, Antonio
    A New Role for Lipocalin Prostaglandin D Synthase in the Regulation of Brown Adipose Tissue Substrate Utilization2012In: Diabetes, ISSN 0012-1797, E-ISSN 1939-327X, Vol. 61, no 12, p. 3139-3147Article in journal (Refereed)
    Abstract [en]

    In this study, we define a new role for lipocalin prostaglandin D synthase (L-PGDS) in the control of metabolic fuel utilization by brown adipose tissue (BAT). We demonstrate that L-PGDS expression in BAT is positively correlated with BAT activity, upregulated by peroxisome proliferator activated receptor gamma coactivator 1 alpha or 1 beta and repressed by receptor-interacting protein 140. Under cold-acclimated conditions, mice lacking L-PGDS had elevated reliance on carbohydrate to provide fuel for thermogenesis and had increased expression of genes regulating glycolysis mid de novo lipogenesis in BAT. These transcriptional differences were associated with increased lipid content in BAT and a BAT lipid composition enriched with de novo synthesized lipids. Consistent with the concept that lack of L-PGDS increases glucose utilization, mice lacking L-PGDS had improved glucose tolerance after high-fat, feeding. The improved glucose tolerance appeared to be independent of changes in insulin sensitivity, as insulin levels during the glucose tolerance test and insulin, leptin, and adiponectin levels were unchanged. Moreover, L-PGDS knock-out mice exhibited increased expression of genes involved in thermogenesis and increased norepinephrine-stimulated glucose uptake to BAT, suggesting that sympathetically mediated changes in glucose uptake may have improved glucose tolerance. Taken together, these results suggest that L-PGDS plays an important role in the regulation of glucose utilization in vivo. Diabetes 61:3139-3147, 2012

  • 83.
    von Essen, Gabriella
    et al.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Englund, Petter
    Cannon, Barbara
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Nedergaard, Jan
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    At thermoneutrality, medium-chain fatty acids totally protect against diet-induced obesity in a UCP1-independent mannerManuscript (preprint) (Other academic)
  • 84.
    von Essen, Gabriella
    et al.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Lindsund, Erik
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Cannon, Barbara
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Nedergaard, Jan
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Adaptive Facultative Diet-induced Thermogenesis in Wild-type but not in UCP1-ablated MiceManuscript (preprint) (Other academic)
  • 85.
    von Essen, Gabriella
    et al.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Lindsund, Erik
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Cannon, Barbara
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Nedergaard, Jan
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Adaptive facultative diet-induced thermogenesis in wild-type but not in UCP1-ablated mice2017In: American Journal of Physiology. Endocrinology and Metabolism, ISSN 0193-1849, E-ISSN 1522-1555, Vol. 313, no 5, p. E515-E527Article in journal (Refereed)
    Abstract [en]

    The significance of diet-induced thermogenesis (DIT) for metabolic control is still debated. Although obesogenic diets recruit UCP1 and adrenergically inducible thermogenesis, and although the absence of UCP1 may promote the development of obesity, no actual UCP1-related thermogenesis identifiable as diet-induced thermogenesis has to date been unambiguously demonstrated. Examining mice living at thermoneutrality, we have identified a process of facultative (directly elicited by acute eating), adaptive (magnitude develops over weeks on an obesogenic diet), and fully UCP1-dependent thermogenesis. We found no evidence for UCP1-independent diet-induced thermogenesis. The thermogenesis was proportional to the total amount of UCP1 protein in brown adipose tissue and was not dependent on any contribution of UCP1 in brite/beige adipose tissue, since no UCP1 protein was found there under these conditions. Total UCP1 protein amount developed proportionally to total body fat content. The physiological messenger linking obesity level and acute eating to increased thermogenesis is not known. Thus UCP1-dependent diet-induced thermogenesis limits obesity development during exposure to obesogenic diets but does not prevent obesity as such.

  • 86.
    von Essen, Gabriella
    et al.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Lindsund, Erik
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Maldonado, Elaina
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Zouhar, Petr
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute. Institute of Physiology of the Czech Academy of Sciences, Czech Republic.
    Cannon, Barbara
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Nedergaard, Jan
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Highly recruited brown adipose tissue does not in itself protect against obesity2023In: Molecular Metabolism, ISSN 2212-8778, Vol. 76, article id 101782Article in journal (Refereed)
    Abstract [en]

    Objective: The possibility to counteract the development of obesity in humans by recruiting brown or brite/beige adipose tissue (and thus UCP1) has attracted much attention. Here we examine if a diet that can activate diet-induced thermogenesis can exploit pre-enhanced amounts of UCP1 to counteract the development of diet-induced obesity.Methods: To investigate the anti-obesity significance of highly augmented amounts of UCP1 for control of body energy reserves, we physiologically increased total UCP1 amounts by recruitment of brown and brite/beige tissues in mice. We then examined the influence of the augmented UCP1 levels on metabolic parameters when the mice were exposed to a high-fat/high-sucrose diet under thermoneutral conditions.Results: The total UCP1 levels achieved were about 50-fold higher in recruited than in non-recruited mice. Contrary to underlying expectations, in the mice with highly recruited UCP1 and exposed to a high-fat/high-sucrose diet the thermogenic capacity of this UCP1 was completely inactivate. The mice even transiently (in an adipostat-like manner) demonstrated a higher metabolic efficiency and fat gain than did non-recruited mice. This was accomplished without altering energy expenditure or food absorption efficiency. The metabolic efficiency here was indistinguishable from that of mice totally devoid of UCP1.Conclusions: Although UCP1 protein may be available, it is not inevitably utilized for diet-induced thermogenesis. Thus, although attempts to recruit UCP1 in humans may become successful as such, it is only if constant activation of the UCP1 is also achieved that amelioration of obesity development could be attained.& COPY; 2023 The Authors. Published by Elsevier GmbH. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

  • 87.
    von Essen, Gabriella
    et al.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Maldonado, Elaina
    Lindsund, Erik
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Cannon, Barbara
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Nedergaard, Jan
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Highly recruited brown adipose tissue does not in itself protect against obesityManuscript (preprint) (Other academic)
  • 88.
    Walden, Tomas B
    et al.
    Stockholm University, Faculty of Science, The Wenner-Gren Institute , Department of Physiology. Stockholm University, Faculty of Science, The Wenner-Gren Institute .
    Timmons, James A
    Keller, Pernille
    Nedergaard, Jan
    Stockholm University, Faculty of Science, The Wenner-Gren Institute , Department of Physiology. Stockholm University, Faculty of Science, The Wenner-Gren Institute .
    Cannon, Barbara
    Stockholm University, Faculty of Science, The Wenner-Gren Institute , Department of Physiology. Stockholm University, Faculty of Science, The Wenner-Gren Institute .
    Distinct expression of muscle-specific microRNAs (myomirs) in brown adipocytes.2009In: Journal of Cellular Physiology, ISSN 0021-9541, E-ISSN 1097-4652, Vol. 218, no 2, p. 444-449Article in journal (Refereed)
    Abstract [en]

    MicroRNAs, a novel class of post-transcriptional gene regulators, have been demonstrated to be involved in several cellular processes regulating the expression of protein-coding genes. Here we examine murine white and brown primary cell cultures for differential expression of miRNAs. The adipogenesis-related miRNA miR-143 was highly expressed in mature white adipocytes but was low in mature brown adipocytes. Three classical "myogenic" miRNAs miR-1, miR-133a and miR-206 were absent from white adipocytes but were specifically expressed both in brown pre- and mature adipocytes, reinforcing the concept that brown adipocytes and myocytes derive from a common cell lineage that specifies energy-dissipating cells. Augmentation of adipocyte differentiation status with norepinephrine or rosiglitazone did not affect the expression of the above miRNAs, the expression levels of which were thus innately regulated. However, expression of the miRNA miR-455 was enhanced during brown adipocyte differentiation, similarly to the expression pattern of the brown adipocyte differentiation marker UCP1. In conclusion, miRNAs are differentially expressed in white and brown adipocytes and may be important in defining the common precursor cell for myocytes and brown adipocytes and thus have distinct roles in energy-storing versus energy-dissipating cells.

  • 89.
    Waldén, Tomas B.
    et al.
    Stockholm University, Faculty of Science, The Wenner-Gren Institute .
    Hansen, Ida R.
    Timmons, James A.
    Cannon, Barbara
    Stockholm University, Faculty of Science, The Wenner-Gren Institute .
    Nedergaard, Jan
    Stockholm University, Faculty of Science, The Wenner-Gren Institute .
    Molecular signatures of brown, white and brite adipose tissues.Manuscript (preprint) (Other academic)
    Download full text (pdf)
    FULLTEXT01
  • 90.
    Waldén, Tomas B.
    et al.
    Stockholm University, Faculty of Science, The Wenner-Gren Institute.
    Hansen, Ida R.
    Stockholm University, Faculty of Science, The Wenner-Gren Institute.
    Timmons, James A.
    Stockholm University, Faculty of Science, The Wenner-Gren Institute. The Royal Veterinary College, United Kingdom.
    Cannon, Barbara
    Stockholm University, Faculty of Science, The Wenner-Gren Institute. The Royal Veterinary College, United Kingdom.
    Nedergaard, Jan
    Stockholm University, Faculty of Science, The Wenner-Gren Institute.
    Recruited vs. nonrecruited molecular signatures of brown, “brite,” and white adipose tissues2012In: American Journal of Physiology. Endocrinology and Metabolism, ISSN 0193-1849, E-ISSN 1522-1555, Vol. 302, no 1, p. E19-E31Article in journal (Refereed)
    Abstract [en]

    Mainly from cell culture studies, a series of genes have been identified that have been suggested to be characteristic of different types of adipocytes. Here we have examined gene expression patterns in nine defined adipose depots: interscapular BAT, cervical BAT, axillary BAT, mediastinic BAT, cardiac WAT, inguinal WAT, retroperitoneal WAT, mesenteric WAT and epididymal WAT. We found that each depot displayed a distinct gene expression fingerprint, but that three major types of depots were identifiable: the brown, the brite and the white. Although differences in gene expression pattern were generally quantitative, some gene markers showed, even in-vivo, remarkable depot specificities: Zic1 for the classical brown adipose tissue depots, Hoxc9 for the brite depots, Hoxc8 for the brite and white in contrast to the brown, and Tcf21 for the white depots. The significance of these gene expression patterns both for understanding the developmental background of the depots and as possible master regulators is discussed.

  • 91. Whittle, Andrew J.
    et al.
    Carobbio, Stefania
    Martins, Luis
    Slawik, Marc
    Hondares, Elayne
    Jesus Vazquez, Maria
    Morgan, Donald
    Csikasz, Robert I.
    Stockholm University, Faculty of Science, The Wenner-Gren Institute , Physiology.
    Gallego, Rosalia
    Rodriguez-Cuenca, Sergio
    Dale, Martin
    Virtue, Samuel
    Villarroya, Francesc
    Cannon, Barbara
    Stockholm University, Faculty of Science, The Wenner-Gren Institute , Physiology.
    Rahmouni, Kamal
    Lopez, Miguel
    Vidal-Puig, Antonio
    BMP8B Increases Brown Adipose Tissue Thermogenesis through Both Central and Peripheral Actions2012In: Cell, ISSN 0092-8674, E-ISSN 1097-4172, Vol. 149, no 4, p. 871-885Article in journal (Refereed)
    Abstract [en]

    Thermogenesis in brown adipose tissue (BAT) is fundamental to energy balance and is also relevant for humans. Bone morphogenetic proteins (BMPs) regulate adipogenesis, and, here, we describe a role for BMP8B in the direct regulation of thermogenesis. BMP8B is induced by nutritional and thermogenic factors in mature BAT, increasing the response to noradrenaline through enhanced p38MAPK/CREB signaling and increased lipase activity. Bmp8b(-/-) mice exhibit impaired thermogenesis and reduced metabolic rate, causing weight gain despite hypophagia. BMP8B is also expressed in the hypothalamus, and Bmp8b(-/-) mice display altered neuropeptide levels and reduced phosphorylation of AMP-activated protein kinase (AMPK), indicating an anorexigenic state. Central BMP8B treatment increased sympathetic activation of BAT, dependent on the status of AMPK in key hypothalamic nuclei. Our results indicate that BMP8B is a thermogenic protein that regulates energy balance in partnership with hypothalamic AMPK. BMP8B may offer a mechanism to specifically increase energy dissipation by BAT.

  • 92.
    Wikström, Jakob D.
    et al.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute. Boston University, USA.
    Mahdaviani, Kiana
    Liesa, Marc
    Sereda, Samuel B.
    Si, Yaguang
    Las, Guy
    Twig, Gilad
    Petrovic, Natasa
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Zingaretti, Cristina
    Graham, Adam
    Cinti, Saverio
    Corkey, Barbara E.
    Cannon, Barbara
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Nedergaard, Jan
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Shirihai, Orian S.
    Hormone-induced mitochondrial fission is utilized by brown adipocytes as an amplification pathway for energy expenditure2014In: EMBO Journal, ISSN 0261-4189, E-ISSN 1460-2075, Vol. 33, no 5, p. 418-436Article in journal (Refereed)
    Abstract [en]

    Adrenergic stimulation of brown adipocytes (BA) induces mitochondrial uncoupling, thereby increasing energy expenditure by shifting nutrient oxidation towards thermogenesis. Here we describe that mitochondrial dynamics is a physiological regulator of adrenergically-induced changes in energy expenditure. The sympathetic neurotransmitter Norepinephrine (NE) induced complete and rapid mitochondrial fragmentation in BA, characterized by Drp1 phosphorylation and Opa1 cleavage. Mechanistically, NE-mediated Drp1 phosphorylation was dependent on Protein Kinase-A (PKA) activity, whereas Opa1 cleavage required mitochondrial depolarization mediated by FFAs released as a result of lipolysis. This change in mitochondrial architecture was observed both in primary cultures and brown adipose tissue from cold-exposed mice. Mitochondrial uncoupling induced by NE in brown adipocytes was reduced by inhibition of mitochondrial fission through transient Drp1 DN overexpression. Furthermore, forced mitochondrial fragmentation in BA through Mfn2 knock down increased the capacity of exogenous FFAs to increase energy expenditure. These results suggest that, in addition to its ability to stimulate lipolysis, NE induces energy expenditure in BA by promoting mitochondrial fragmentation. Together these data reveal that adrenergically-induced changes to mitochondrial dynamics are required for BA thermogenic activation and for the control of energy expenditure.

  • 93. Xue, Yuan
    et al.
    Petrovic, Natasa
    Stockholm University, Faculty of Science, The Wenner-Gren Institute, Physiology.
    Cao, Renhai
    Larsson, Ola
    Lim, Sharon
    Chen, Shaohua
    Feldmann, Helena M.
    Stockholm University, Faculty of Science, The Wenner-Gren Institute, Physiology.
    Liang, Zicai
    Zhu, Zhenping
    Nedergaard, Jan
    Stockholm University, Faculty of Science, The Wenner-Gren Institute, Physiology.
    Cannon, Barbara
    Stockholm University, Faculty of Science, The Wenner-Gren Institute, Physiology.
    Cao, Yihai
    Hypoxia-independent angiogenesis in adipose tissues during cold acclimation.2009In: Cell Metabolism, ISSN 1550-4131, E-ISSN 1932-7420, Vol. 9, no 1, p. 99-109Article in journal (Refereed)
    Abstract [en]

    The molecular mechanisms of angiogenesis in relation to adipose tissue metabolism remain poorly understood. Here, we show that exposure of mice to cold led to activation of angiogenesis in both white and brown adipose tissues. In the inguinal depot, cold exposure resulted in elevated expression levels of brown-fat-associated proteins, including uncoupling protein-1 (UCP1) and PGC-1alpha. Proangiogenic factors such as VEGF were upregulated, and endogenous angiogenesis inhibitors, including thrombospondin, were downregulated. In wild-type mice, the adipose tissues became hypoxic during cold exposure; in UCP1(-/-) mice, hypoxia did not occur, but, remarkably, the augmented angiogenesis was unaltered and was thus hypoxia independent. Intriguingly, VEGFR2 blockage abolished the cold-induced angiogenesis and significantly impaired nonshivering thermogenesis capacity. Unexpectedly, VEGFR1 blockage resulted in the opposite effects: increased adipose vascularity and nonshivering thermogenesis capacity. Our findings have conceptual implications concerning application of angiogenesis modulators for treatment of obesity and metabolic disorders.

  • 94. Zenius Jespersen, Naja
    et al.
    Juhlin Larsen, Therese
    Peijs, Lone
    Daugaard, Søren
    Homøe, Preben
    Loft, Annika
    de Jong, Jasper
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Mathur, Neha
    Cannon, Barbara
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Nedergaard, Jan
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Klarlund Pedersen, Bente
    Møller, Kirsten
    Scheele, Camilla
    A classical brown adipose tissue mRNA signature partly overlaps with brite in the supraclavicular region of adult humans2013In: Cell Metabolism, ISSN 1550-4131, E-ISSN 1932-7420, Vol. 17, no 5, p. 798-805Article in journal (Refereed)
    Abstract [en]

    Human brown adipose tissue (BAT) has been detected in adults but was recently suggested to be of brite/beige origin. We collected BAT from the supraclavicular region in 21 patients undergoing surgery for suspected cancer in the neck area and assessed the gene expression of established murine markers for brown, brite/beige, and white adipocytes. We demonstrate that a classical brown expression signature, including upregulation of miR-206, miR-133b, LHX8, and ZIC1 and downregulation of HOXC8 and HOXC9, coexists with an upregulation of two newly established brite/beige markers, TBX1 and TMEM26. A similar mRNA expression profile was observed when comparing isolated human adipocytes from BAT and white adipose tissue (WAT) depots, differentiated in vitro. In conclusion, our data suggest that human BAT might consist of both classical brown and recruitable brite adipocytes, an observation important for future considerations on how to induce human BAT.

  • 95. Zingaretti, Maria Cristina
    et al.
    Crosta, Francesca
    Vitali, Alessandra
    Guerrieri, Mario
    Frontini, Andrea
    Cannon, Barbara
    Stockholm University, Faculty of Science, The Wenner-Gren Institute , Physiology.
    Nedergaard, Jan
    Stockholm University, Faculty of Science, The Wenner-Gren Institute , Physiology.
    Cinti, Saverio
    The presence of UCP1 demonstrates that metabolically active adipose tissue in the neck of adult humans truly represents brown adipose tissue.2009In: The FASEB Journal, ISSN 0892-6638, E-ISSN 1530-6860, Vol. 23, no 9, p. 3113-20Article in journal (Refereed)
    Abstract [en]

    Classically, adult humans have been considered not to possess active brown adipose tissue (BAT). However, positron-emission-tomography has shown fluorodeoxyglucose uptake that is distributed in such a way (e.g., in the neck) that it would seem to be BAT. Until now this has not been supported by direct evidence that these areas truly represented BAT, that is, the presence of the BAT-unique uncoupling protein-1 (UCP1). Samples of adipose tissue from the neck of 35 patients undergoing surgery for thyroid diseases were obtained and analyzed. In 1/3 of the subjects (the younger and leaner), distinct islands composed of UCP1 immunoreactive brown adipocytes could clearly be discerned, accounting for up to 1/3 of all adipocytes. The brown-adipose islands were richly sympathetically innervated (indicating acute central control); adjacent white adipose areas were not. The capillary density was high, implying a high capacity for oxygen delivery. Cells with features of brown adipocyte precursors were found in pericapillary areas. These data demonstrate that human adults indeed possess BAT and thus imply possibilities of future therapeutic strategies for the treatment of obesity, including maintenance of brown adipocytes and stimulation of the growth of preexisting brown precursors.

  • 96. Zouhar, Petr
    et al.
    Janovska, Petra
    Stanic, Sara
    Bardova, Kristina
    Funda, Jiri
    Haberlova, Blanka
    Andersen, Birgitte
    Rossmeisl, Martin
    Cannon, Barbara
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Kopecky, Jan
    Nedergaard, Jan
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    A pyrexic effect of FGF21 independent of energy expenditure and UCP12021In: Molecular Metabolism, ISSN 2212-8778, Vol. 53, article id 101324Article in journal (Refereed)
    Abstract [en]

    Objective: Administration of FGF21 to mice reduces body weight and increases body temperature. The increase in body temperature is generally interpreted as hyperthermia, i.e. a condition secondary to the increase in energy expenditure (heat production). Here, we examine an alternative hypothesis: that FGF21 has a direct pyrexic effect, i.e. FGF21 increases body temperature independently of any effect on energy expenditure.

    Methods: We studied the effects of FGF21 treatment on body temperature and energy expenditure in high-fat-diet-fed and chow-fed mice exposed acutely to various ambient temperatures, in high-fat diet-fed mice housed at 30 °C (i.e. at thermoneutrality), and in mice lacking uncoupling protein 1 (UCP1).

    Results: In every model studied, FGF21 increased body temperature, but energy expenditure was increased only in some models. The effect of FGF21 on body temperature was more (not less, as expected in hyperthermia) pronounced at lower ambient temperatures. Effects on body temperature and energy expenditure were temporally distinct (daytime versus nighttime). FGF21 enhanced UCP1 protein content in brown adipose tissue (BAT); there was no measurable UCP1 protein in inguinal brite/beige adipose tissue. FGF21 increased energy expenditure through adrenergic stimulation of BAT. In mice lacking UCP1, FGF21 did not increase energy expenditure but increased body temperature by reducing heat loss, e.g. a reduced tail surface temperature.

    Conclusion: The effect of FGF21 on body temperature is independent of UCP1 and can be achieved in the absence of any change in energy expenditure. Since elevated body temperature is a primary effect of FGF21 and can be achieved without increasing energy expenditure, only limited body weight-lowering effects of FGF21 may be expected.

  • 97.
    Zouhar, Petr
    et al.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute. Institute of Physiology CAS, the Czech Republic.
    Rakipovski, Gunaj
    Bokhari, Muhammad Hamza
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Busby, Oliver
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Paulsson, Johan F.
    Conde-Frieboes, Kilian W.
    Fels, Johannes J.
    Raun, Kirsten
    Andersen, Birgitte
    Cannon, Barbara
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Nedergaard, Jan
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    UCP1-independent glucose-lowering effect of leptin in type 1 diabetes: only in conditions of hypoleptinemia2020In: American Journal of Physiology. Endocrinology and Metabolism, ISSN 0193-1849, E-ISSN 1522-1555, Vol. 318, no 1, p. E72-E86Article in journal (Refereed)
    Abstract [en]

    The possibility to use leptin therapeutically for lowering glucose levels in patients with type 1 diabetes has attracted interest. However, earlier animal models of type 1 diabetes are severely catabolic with very low endogenous leptin levels, unlike most patients with diabetes. Here, we aim to test glucose-lowering effects of leptin in novel, more human-like murine models. We examined the glucose-lowering potential of leptin in diabetic models of two types: streptozotocin-treated mice and mice treated with the insulin receptor antagonist S961. To prevent hypoleptinemia, we used combinations of thermoneutral temperature and high-fat feeding. Leptin fully normalized hyperglycemia in standard chow-fed streptozotocin-treated diabetic mice. However, more humanized physiological conditions (high-fat diets or thermoneutral temperatures) that increased adiposity- and thus also leptin level-sin the diabetic mice abrogated the effects of leptin, i.e., the mice developed leptin resistance also in this respect. The glucose-lowering effect of leptin was not dependent on the presence of the uncoupling protein-1 and was not associated with alterations in plasma insulin, insulin-like growth factor 1, food intake or corticosterone but fully correlated with decreased plasma glucagon levels and gluconeogenesis. An important implication of these observations is that the therapeutic potential of leptin as an additional treatment in patients with type 1 diabetes is probably limited. This is because such patients are treated with insulin and do not display low leptin levels. Thus, the potential for a glucose-lowering effect of leptin would already have been attained with standard insulin therapy, and further effects on blood glucose level through additional leptin cannot be anticipated.

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