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Allard C, Miralpeix C, López-Gambero AJ, Cota D. mTORC1 in energy expenditure: consequences for obesity. Nat Rev Endocrinol 2024; 20:239-251. [PMID: 38225400 DOI: 10.1038/s41574-023-00934-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/29/2023] [Indexed: 01/17/2024]
Abstract
In eukaryotic cells, the mammalian target of rapamycin complex 1 (sometimes referred to as the mechanistic target of rapamycin complex 1; mTORC1) orchestrates cellular metabolism in response to environmental energy availability. As a result, at the organismal level, mTORC1 signalling regulates the intake, storage and use of energy by acting as a hub for the actions of nutrients and hormones, such as leptin and insulin, in different cell types. It is therefore unsurprising that deregulated mTORC1 signalling is associated with obesity. Strategies that increase energy expenditure offer therapeutic promise for the treatment of obesity. Here we review current evidence illustrating the critical role of mTORC1 signalling in the regulation of energy expenditure and adaptive thermogenesis through its various effects in neuronal circuits, adipose tissue and skeletal muscle. Understanding how mTORC1 signalling in one organ and cell type affects responses in other organs and cell types could be key to developing better, safer treatments targeting this pathway in obesity.
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Affiliation(s)
- Camille Allard
- University of Bordeaux, INSERM, Neurocentre Magendie, Bordeaux, France
| | | | | | - Daniela Cota
- University of Bordeaux, INSERM, Neurocentre Magendie, Bordeaux, France.
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2
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Zhu Y, Liu W, Qi Z. Adipose tissue browning and thermogenesis under physiologically energetic challenges: a remodelled thermogenic system. J Physiol 2024; 602:23-48. [PMID: 38019069 DOI: 10.1113/jp285269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 11/16/2023] [Indexed: 11/30/2023] Open
Abstract
Metabolic diseases such as obesity and diabetes are often thought to be caused by reduced energy expenditure, which poses a serious threat to human health. Cold exposure, exercise and caloric restriction have been shown to promote adipose tissue browning and thermogenesis. These physiological interventions increase energy expenditure and thus have emerged as promising strategies for mitigating metabolic disorders. However, that increased adipose tissue browning and thermogenesis elevate thermogenic consumption is not a reasonable explanation when humans and animals confront energetic challenges imposed by these interventions. In this review, we collected numerous results on adipose tissue browning and whitening and evaluated this bi-directional conversion of adipocytes from the perspective of energy homeostasis. Here, we propose a new interpretation of the role of adipose tissue browning under energetic challenges: increased adipose tissue browning and thermogenesis under energy challenge is not to enhance energy expenditure, but to reestablish a more economical thermogenic pattern to maintain the core body temperature. This can be achieved by enhancing the contribution of non-shivering thermogenesis (adipose tissue browning and thermogenesis) and lowering shivering thermogenesis and high intensity shivering. Consequently, the proportion of heat production in fat increases and that in skeletal muscle decreases, enabling skeletal muscle to devote more energy reserves to overcoming environmental stress.
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Affiliation(s)
- Yupeng Zhu
- The Key Laboratory of Adolescent Health Assessment and Exercise Intervention (Ministry of Education), East China Normal University, Shanghai, China
- School of Physical Education and Health, East China Normal University, Shanghai, China
- Sino-French Joint Research Center of Sport Science, East China Normal University, Shanghai, China
| | - Weina Liu
- The Key Laboratory of Adolescent Health Assessment and Exercise Intervention (Ministry of Education), East China Normal University, Shanghai, China
- School of Physical Education and Health, East China Normal University, Shanghai, China
| | - Zhengtang Qi
- The Key Laboratory of Adolescent Health Assessment and Exercise Intervention (Ministry of Education), East China Normal University, Shanghai, China
- School of Physical Education and Health, East China Normal University, Shanghai, China
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3
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Ortiz-Silva M, Leonardi BF, Castro É, Peixoto ÁS, Gilio GR, Oliveira TE, Tomazelli CA, Andrade ML, Moreno MF, Belchior T, Magdalon J, Vieira TS, Donado-Pestana CM, Festuccia WT. Chloroquine attenuates diet-induced obesity and glucose intolerance through a mechanism that might involve FGF-21, but not UCP-1-mediated thermogenesis and inhibition of adipocyte autophagy. Mol Cell Endocrinol 2023; 578:112074. [PMID: 37742789 DOI: 10.1016/j.mce.2023.112074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 09/19/2023] [Accepted: 09/20/2023] [Indexed: 09/26/2023]
Abstract
Chloroquine diphosphate (CQ), a weak base used to inhibit autophagic flux and treat malaria and rheumatoid diseases, has been shown, through unknown mechanisms, to improve glucose and lipid homeostasis in patients and rodents. We investigate herein the molecular mechanisms underlying these CQ beneficial metabolic actions in diet-induced obese mice. For this, C57BL6/J mice fed with either a chow or a high-fat diet (HFD) and uncoupling protein 1 (UCP-1) KO and adipocyte Atg7-deficient mice fed with a HFD were treated or not with CQ (60 mg/kg of body weight/day) during 8 weeks and evaluated for body weight, adiposity, glucose homeostasis and brown and white adipose tissues (BAT and WAT) UCP-1 content. CQ reduced body weight gain and adipose tissue and liver masses in mice fed with a HFD, without altering food intake, oxygen consumption, respiratory exchange ratio, spontaneous motor activity and feces caloric content. CQ attenuated the insulin intolerance, hyperglycemia, hyperinsulinemia, hypertriglyceridemia and hypercholesterolemia induced by HFD intake, such effects that were associated with increases in serum and liver fibroblast growth factor 21 (FGF-21) and BAT and WAT UCP-1 content. Interestingly, CQ beneficial metabolic actions of reducing body weight and adiposity and improving glucose homeostasis were preserved in HFD-fed UCP-1 KO and adipocyte Atg7 deficient mice. CQ reduces body weight gain and adiposity and improves glucose homeostasis in diet-induced obese mice through mechanisms that might involve FGF-21, but not UCP1-mediated nonshivering thermogenesis or inhibition of adipocyte autophagy.
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Affiliation(s)
- Milene Ortiz-Silva
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de Sao Paulo, Av. Prof Lineu Prestes 1524, Sao Paulo, 05508000, Brazil
| | - Bianca F Leonardi
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de Sao Paulo, Av. Prof Lineu Prestes 1524, Sao Paulo, 05508000, Brazil
| | - Érique Castro
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de Sao Paulo, Av. Prof Lineu Prestes 1524, Sao Paulo, 05508000, Brazil
| | - Álbert S Peixoto
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de Sao Paulo, Av. Prof Lineu Prestes 1524, Sao Paulo, 05508000, Brazil
| | - Gustavo R Gilio
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de Sao Paulo, Av. Prof Lineu Prestes 1524, Sao Paulo, 05508000, Brazil
| | - Tiago E Oliveira
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de Sao Paulo, Av. Prof Lineu Prestes 1524, Sao Paulo, 05508000, Brazil
| | - Caroline A Tomazelli
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de Sao Paulo, Av. Prof Lineu Prestes 1524, Sao Paulo, 05508000, Brazil
| | - Maynara L Andrade
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de Sao Paulo, Av. Prof Lineu Prestes 1524, Sao Paulo, 05508000, Brazil
| | - Mayara F Moreno
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de Sao Paulo, Av. Prof Lineu Prestes 1524, Sao Paulo, 05508000, Brazil
| | - Thiago Belchior
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de Sao Paulo, Av. Prof Lineu Prestes 1524, Sao Paulo, 05508000, Brazil
| | - Juliana Magdalon
- Faculdade Israelita de Ciências da Saúde Albert Einstein, Hospital Israelita Albert Einstein, Sao Paulo, SP, 05606300, Brazil
| | - Thayna S Vieira
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de Sao Paulo, Av. Prof Lineu Prestes 1524, Sao Paulo, 05508000, Brazil
| | - Carlos M Donado-Pestana
- Departamento de Alimentos e Nutrição Experimental, Faculdade de Ciências Farmacêuticas, Universidade de Sao Paulo, Av. Prof Lineu Prestes 580, Sao Paulo, SP, 05508000, Brazil; Food Research Center FoRC, Universidade de Sao Paulo, Av. Prof Lineu Prestes 580, Sao Paulo, SP, 05508000, Brazil
| | - William T Festuccia
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de Sao Paulo, Av. Prof Lineu Prestes 1524, Sao Paulo, 05508000, Brazil.
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Peixoto ÁS, Moreno MF, Castro É, Perandini LA, Belchior T, Oliveira TE, Vieira TS, Gilio GR, Tomazelli CA, Leonardi BF, Ortiz-Silva M, Silva Junior LP, Moretti EH, Steiner AA, Festuccia WT. Hepatocellular carcinoma induced by hepatocyte Pten deletion reduces BAT UCP-1 and thermogenic capacity in mice, despite increasing serum FGF-21 and iWAT browning. J Physiol Biochem 2023; 79:731-743. [PMID: 37405670 DOI: 10.1007/s13105-023-00970-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Accepted: 06/23/2023] [Indexed: 07/06/2023]
Abstract
Hepatocellular carcinoma (HCC) markedly enhances liver secretion of fibroblast growth factor 21 (FGF-21), a hepatokine that increases brown and subcutaneous inguinal white adipose tissues (BAT and iWAT, respectively) uncoupling protein 1 (UCP-1) content, thermogenesis and energy expenditure. Herein, we tested the hypothesis that an enhanced BAT and iWAT UCP-1-mediated thermogenesis induced by high levels of FGF-21 is involved in HCC-associated catabolic state and fat mass reduction. For this, we evaluated body weight and composition, liver mass and morphology, serum and tissue levels of FGF-21, BAT and iWAT UCP-1 content, and thermogenic capacity in mice with Pten deletion in hepatocytes that display a well-defined progression from steatosis to steatohepatitis (NASH) and HCC upon aging. Hepatocyte Pten deficiency promoted a progressive increase in liver lipid deposition, mass, and inflammation, culminating with NASH at 24 weeks and hepatomegaly and HCC at 48 weeks of age. NASH and HCC were associated with elevated liver and serum FGF-21 content and iWAT UCP-1 expression (browning), but reduced serum insulin, leptin, and adiponectin levels and BAT UCP-1 content and expression of sympathetically regulated gene glycerol kinase (GyK), lipoprotein lipase (LPL), and fatty acid transporter protein 1 (FATP-1), which altogether resulted in an impaired whole-body thermogenic capacity in response to CL-316,243. In conclusion, FGF-21 pro-thermogenic actions in BAT are context-dependent, not occurring in NASH and HCC, and UCP-1-mediated thermogenesis is not a major energy-expending process involved in the catabolic state associated with HCC induced by Pten deletion in hepatocytes.
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Affiliation(s)
- Álbert S Peixoto
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Av. Prof Lineu Prestes, 1524, 05508000, Sao Paulo, Brazil
| | - Mayara F Moreno
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Av. Prof Lineu Prestes, 1524, 05508000, Sao Paulo, Brazil
| | - Érique Castro
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Av. Prof Lineu Prestes, 1524, 05508000, Sao Paulo, Brazil
| | - Luiz A Perandini
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Av. Prof Lineu Prestes, 1524, 05508000, Sao Paulo, Brazil
| | - Thiago Belchior
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Av. Prof Lineu Prestes, 1524, 05508000, Sao Paulo, Brazil
| | - Tiago E Oliveira
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Av. Prof Lineu Prestes, 1524, 05508000, Sao Paulo, Brazil
| | - Thayna S Vieira
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Av. Prof Lineu Prestes, 1524, 05508000, Sao Paulo, Brazil
| | - Gustavo R Gilio
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Av. Prof Lineu Prestes, 1524, 05508000, Sao Paulo, Brazil
| | - Caroline A Tomazelli
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Av. Prof Lineu Prestes, 1524, 05508000, Sao Paulo, Brazil
| | - Bianca F Leonardi
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Av. Prof Lineu Prestes, 1524, 05508000, Sao Paulo, Brazil
| | - Milene Ortiz-Silva
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Av. Prof Lineu Prestes, 1524, 05508000, Sao Paulo, Brazil
| | - Luciano P Silva Junior
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Av. Prof Lineu Prestes, 1524, 05508000, Sao Paulo, Brazil
| | - Eduardo H Moretti
- Department of Immunology, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Alexandre A Steiner
- Department of Immunology, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - William T Festuccia
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Av. Prof Lineu Prestes, 1524, 05508000, Sao Paulo, Brazil.
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Caprioli B, Eichler RAS, Silva RNO, Martucci LF, Reckziegel P, Ferro ES. Neurolysin Knockout Mice in a Diet-Induced Obesity Model. Int J Mol Sci 2023; 24:15190. [PMID: 37894869 PMCID: PMC10607720 DOI: 10.3390/ijms242015190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 10/06/2023] [Accepted: 10/09/2023] [Indexed: 10/29/2023] Open
Abstract
Neurolysin oligopeptidase (E.C.3.4.24.16; Nln), a member of the zinc metallopeptidase M3 family, was first identified in rat brain synaptic membranes hydrolyzing neurotensin at the Pro-Tyr peptide bond. The previous development of C57BL6/N mice with suppression of Nln gene expression (Nln-/-), demonstrated the biological relevance of this oligopeptidase for insulin signaling and glucose uptake. Here, several metabolic parameters were investigated in Nln-/- and wild-type C57BL6/N animals (WT; n = 5-8), male and female, fed either a standard (SD) or a hypercaloric diet (HD), for seven weeks. Higher food intake and body mass gain was observed for Nln-/- animals fed HD, compared to both male and female WT control animals fed HD. Leptin gene expression was higher in Nln-/- male and female animals fed HD, compared to WT controls. Both WT and Nln-/- females fed HD showed similar gene expression increase of dipeptidyl peptidase 4 (DPP4), a peptidase related to glucagon-like peptide-1 (GLP-1) metabolism. The present data suggest that Nln participates in the physiological mechanisms related to diet-induced obesity. Further studies will be necessary to better understand the molecular mechanism responsible for the higher body mass gain observed in Nln-/- animals fed HD.
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Affiliation(s)
- Bruna Caprioli
- Pharmacology Department, Biomedical Sciences Institute (ICB), São Paulo 05508-000, SP, Brazil; (B.C.); (R.A.S.E.); (R.N.O.S.); (L.F.M.)
| | - Rosangela A. S. Eichler
- Pharmacology Department, Biomedical Sciences Institute (ICB), São Paulo 05508-000, SP, Brazil; (B.C.); (R.A.S.E.); (R.N.O.S.); (L.F.M.)
| | - Renée N. O. Silva
- Pharmacology Department, Biomedical Sciences Institute (ICB), São Paulo 05508-000, SP, Brazil; (B.C.); (R.A.S.E.); (R.N.O.S.); (L.F.M.)
| | - Luiz Felipe Martucci
- Pharmacology Department, Biomedical Sciences Institute (ICB), São Paulo 05508-000, SP, Brazil; (B.C.); (R.A.S.E.); (R.N.O.S.); (L.F.M.)
| | - Patricia Reckziegel
- Department of Clinical and Toxicological Analysis, Faculty of Pharmaceutical Sciences (FCF), University of São Paulo (USP), São Paulo 05508-000, SP, Brazil;
| | - Emer S. Ferro
- Pharmacology Department, Biomedical Sciences Institute (ICB), São Paulo 05508-000, SP, Brazil; (B.C.); (R.A.S.E.); (R.N.O.S.); (L.F.M.)
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6
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Chaves-Filho AB, Peixoto AS, Castro É, Oliveira TE, Perandini LA, Moreira RJ, da Silva RP, da Silva BP, Moretti EH, Steiner AA, Miyamoto S, Yoshinaga MY, Festuccia WT. Futile cycle of β-oxidation and de novo lipogenesis are associated with essential fatty acids depletion in lipoatrophy. Biochim Biophys Acta Mol Cell Biol Lipids 2023; 1868:159264. [PMID: 36535597 DOI: 10.1016/j.bbalip.2022.159264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 11/08/2022] [Accepted: 12/05/2022] [Indexed: 12/23/2022]
Abstract
Total absence of adipose tissue (lipoatrophy) is associated with the development of severe metabolic disorders including hepatomegaly and fatty liver. Here, we sought to investigate the impact of severe lipoatrophy induced by deletion of peroxisome proliferator-activated receptor gamma (PPARγ) exclusively in adipocytes on lipid metabolism in mice. Untargeted lipidomics of plasma, gastrocnemius and liver uncovered a systemic depletion of the essential linoleic (LA) and α-linolenic (ALA) fatty acids from several lipid classes (storage lipids, glycerophospholipids, free fatty acids) in lipoatrophic mice. Our data revealed that such essential fatty acid depletion was linked to increased: 1) capacity for liver mitochondrial fatty acid β-oxidation (FAO), 2) citrate synthase activity and coenzyme Q content in the liver, 3) whole-body oxygen consumption and reduced respiratory exchange rate in the dark period, and 4) de novo lipogenesis and carbon flux in the TCA cycle. The key role of de novo lipogenesis in hepatic steatosis was evidenced by an accumulation of stearic, oleic, sapienic and mead acids in liver. Our results thus indicate that the simultaneous activation of the antagonic processes FAO and de novo lipogenesis in liver may create a futile metabolic cycle leading to a preferential depletion of LA and ALA. Noteworthy, this previously unrecognized cycle may also explain the increased energy expenditure displayed by lipoatrophic mice, adding a new piece to the metabolic regulation puzzle in lipoatrophies.
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Affiliation(s)
- Adriano B Chaves-Filho
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, Av. Prof Lineu Prestes 748, São Paulo 05508900, Brazil; Department of Biochemistry, Institute of Chemistry, University of São Paulo, Av. Prof Lineu Prestes 1524, São Paulo 05508000, Brazil.
| | - Albert S Peixoto
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, Av. Prof Lineu Prestes 748, São Paulo 05508900, Brazil
| | - Érique Castro
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, Av. Prof Lineu Prestes 748, São Paulo 05508900, Brazil
| | - Tiago E Oliveira
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, Av. Prof Lineu Prestes 748, São Paulo 05508900, Brazil
| | - Luiz A Perandini
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, Av. Prof Lineu Prestes 748, São Paulo 05508900, Brazil
| | - Rafael J Moreira
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, Av. Prof Lineu Prestes 748, São Paulo 05508900, Brazil
| | - Railmara P da Silva
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, Av. Prof Lineu Prestes 1524, São Paulo 05508000, Brazil
| | - Beatriz P da Silva
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, Av. Prof Lineu Prestes 1524, São Paulo 05508000, Brazil
| | - Eduardo H Moretti
- Department of Immunology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof Lineu Prestes 1524, São Paulo 05508000, Brazil
| | - Alexandre A Steiner
- Department of Immunology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof Lineu Prestes 1524, São Paulo 05508000, Brazil
| | - Sayuri Miyamoto
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, Av. Prof Lineu Prestes 1524, São Paulo 05508000, Brazil
| | - Marcos Y Yoshinaga
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, Av. Prof Lineu Prestes 1524, São Paulo 05508000, Brazil.
| | - William T Festuccia
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, Av. Prof Lineu Prestes 748, São Paulo 05508900, Brazil.
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Physiological and molecular mechanisms of cold-induced improvements in glucose homeostasis in humans beyond brown adipose tissue. Int J Obes (Lond) 2023; 47:338-347. [PMID: 36774412 DOI: 10.1038/s41366-023-01270-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 01/26/2023] [Accepted: 01/31/2023] [Indexed: 02/13/2023]
Abstract
Exposure to low ambient temperatures has previously been demonstrated to markedly improve glucose homeostasis in both rodents and humans. Although the brown adipose tissue is key in mediating these beneficial effects in rodents, its contribution appears more limited in humans. Hence, the exact tissues and underlying mechanisms that mediate cold-induced improvements in glucose homeostasis in humans remain to be fully established. In this review, we evaluated the response of the main organs involved in glucose metabolism (i.e. pancreas, liver, (white) adipose tissue, and skeletal muscle) to cold exposure and discuss their potential contribution to cold-induced improvements in glucose homeostasis in humans. We here show that cold exposure has widespread effects on metabolic organs involved in glucose regulation. Nevertheless, cold-induced improvements in glucose homeostasis appear primarily mediated via adaptations within the skeletal muscle and (presumably) white adipose tissue. Since the underlying mechanisms remain elusive, future studies should be aimed at pinpointing the exact physiological and molecular mechanisms involved in humans. Nonetheless, cold exposure holds great promise as a novel, additive lifestyle approach to improve glucose homeostasis in insulin resistant individuals. Parts of this graphical abstract were created using (modified) images from Servier Medical Art, licensed under the Creative Commons Attribution 3.0 Unported License. TG = thermogenesis, TAG = triacylglycerol, FFA = free fatty acid, SLN = sarcolipin, UCP3 = uncoupling protein 3, β2-AR = beta-2 adrenergic receptor, SNS = sympathetic nervous system.
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Colas C, Mouchiroud M, Al Dow M, Kolnohuz A, Gélinas Y, Caron A, Laplante M. DEPTOR loss impairs brown adipocyte development in vitro but has limited impacts in mice. Mol Metab 2022; 67:101660. [PMID: 36535626 PMCID: PMC9827061 DOI: 10.1016/j.molmet.2022.101660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 12/09/2022] [Accepted: 12/11/2022] [Indexed: 12/23/2022] Open
Abstract
OBJECTIVES The mechanistic target of rapamycin (mTOR) is a serine/threonine kinase that regulates growth and metabolism. In mice, activation of mTOR controls cold adaptation by promoting the recruitment and the activation of brown adipose tissue (BAT). DEP-domain containing mTOR-interacting protein (DEPTOR) interacts with mTOR to modulate its activity. Whether DEPTOR levels are modulated by cold in BAT and whether this protein regulates brown adipocyte development and thermogenic activation has never been tested. METHODS DEPTOR levels were measured in mouse tissues upon cold exposure and in brown preadipocytes following the induction of adipogenesis. Lentiviruses expressing short-hairpin RNA were used to repress DEPTOR expression in brown preadipocytes in vitro. Conditional deletion of DEPTOR in brown preadipocytes and in mature brown fat cells was achieved by crossing DEPTOR floxed mice with either Myf5-Cre or Ucp1-CreERT2 mice. These animals were exposed to cold and extensively phenotyped. RESULTS DEPTOR is highly expressed in BAT and its levels are induced by chronic cold exposure, a condition that triggers BAT expansion and activation. Supporting a role for DEPTOR in brown fat cell recruitment, we found that DEPTOR is induced during brown adipocyte development and that its depletion impairs adipogenesis in vitro. This adipogenic lesion was associated with defects in both Akt activation and the expression of key adipogenic regulators. Conditional deletion of DEPTOR in brown preadipocytes or mature brown fat cells did not impact BAT recruitment and thermogenesis in mice but slightly reduced the expression of adipogenic and lipogenic genes. CONCLUSIONS DEPTOR is highly expressed in BAT and its levels are dynamically regulated during brown fat cell development and upon cold exposure. Although DEPTOR depletion severely represses brown fat adipogenesis in vitro, its deletion is dispensable for BAT development, recruitment, and thermogenic activation in mice.
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Affiliation(s)
- Charles Colas
- Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec - Université Laval (CRIUCPQ), 2725 Chemin Ste-Foy, Québec, QC, Canada, G1V 4G5; Centre de recherche sur le cancer de l'Université Laval, Université Laval, 9 rue McMahon, Québec, QC, Canada, G1R 3S3
| | - Mathilde Mouchiroud
- Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec - Université Laval (CRIUCPQ), 2725 Chemin Ste-Foy, Québec, QC, Canada, G1V 4G5; Centre de recherche sur le cancer de l'Université Laval, Université Laval, 9 rue McMahon, Québec, QC, Canada, G1R 3S3
| | - Manal Al Dow
- Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec - Université Laval (CRIUCPQ), 2725 Chemin Ste-Foy, Québec, QC, Canada, G1V 4G5; Centre de recherche sur le cancer de l'Université Laval, Université Laval, 9 rue McMahon, Québec, QC, Canada, G1R 3S3
| | - Alona Kolnohuz
- Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec - Université Laval (CRIUCPQ), 2725 Chemin Ste-Foy, Québec, QC, Canada, G1V 4G5; Centre de recherche sur le cancer de l'Université Laval, Université Laval, 9 rue McMahon, Québec, QC, Canada, G1R 3S3
| | - Yves Gélinas
- Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec - Université Laval (CRIUCPQ), 2725 Chemin Ste-Foy, Québec, QC, Canada, G1V 4G5; Centre de recherche sur le cancer de l'Université Laval, Université Laval, 9 rue McMahon, Québec, QC, Canada, G1R 3S3
| | - Alexandre Caron
- Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec - Université Laval (CRIUCPQ), 2725 Chemin Ste-Foy, Québec, QC, Canada, G1V 4G5; Faculté de Pharmacie, Université Laval, 1050 avenue de la Médecine, Québec, QC, Canada, G1V0A6
| | - Mathieu Laplante
- Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec - Université Laval (CRIUCPQ), 2725 Chemin Ste-Foy, Québec, QC, Canada, G1V 4G5; Centre de recherche sur le cancer de l'Université Laval, Université Laval, 9 rue McMahon, Québec, QC, Canada, G1R 3S3; Département de Médecine, Université Laval, 1050 avenue de la Médecine, Québec, QC, Canada, G1V0A6.
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Cao Y, Han S, Lu H, Luo Y, Guo T, Wu Q, Luo F. Targeting mTOR Signaling by Dietary Polyphenols in Obesity Prevention. Nutrients 2022; 14:nu14235171. [PMID: 36501200 PMCID: PMC9735788 DOI: 10.3390/nu14235171] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 11/29/2022] [Accepted: 12/01/2022] [Indexed: 12/09/2022] Open
Abstract
Dietary polyphenols can be utilized to treat obesity and chronic disorders linked to it. Dietary polyphenols can inhibit pre-adipocyte proliferation, adipocyte differentiation, and triglyceride accumulation; meanwhile, polyphenols can also stimulate lipolysis and fatty acid β-oxidation, but the molecular mechanisms of anti-obesity are still unclear. The mechanistic target of rapamycin (mTOR) is a protein kinase that regulates cell growth, survival, metabolism, and immunity. mTOR signaling is also thought to play a key role in the development of metabolic diseases such as obesity. Recent studies showed that dietary polyphenols could target mTOR to reduce obesity. In this review, we systematically summarized the research progress of polyphenols in preventing obesity through the mTOR signaling pathway. Mechanistically, polyphenols can target multiple signaling pathways and gut microbiota to regulate the mTOR signaling pathway to exert anti-obesity effects. The main mechanisms include: modulating lipid metabolism, adipogenesis, inflammation, etc. Dietary polyphenols exerting an anti-obesity effect by targeting mTOR signaling will broaden our understanding of the anti-obesity mechanisms of polyphenols and provide valuable insights for researchers in this novel field.
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Affiliation(s)
- Yunyun Cao
- Hunan Provincial Key Laboratory of Grain-Oil Deep Process and Quality Control, Hunan Provincial Key Laboratory of Forestry Edible Resources Safety and Processing, Hunan Provincial Key Laboratory of Processed Food for Special Medical Purpose, College of Food Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China
| | - Shuai Han
- Hunan Provincial Key Laboratory of Grain-Oil Deep Process and Quality Control, Hunan Provincial Key Laboratory of Forestry Edible Resources Safety and Processing, Hunan Provincial Key Laboratory of Processed Food for Special Medical Purpose, College of Food Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China
| | - Han Lu
- Hunan Provincial Key Laboratory of Grain-Oil Deep Process and Quality Control, Hunan Provincial Key Laboratory of Forestry Edible Resources Safety and Processing, Hunan Provincial Key Laboratory of Processed Food for Special Medical Purpose, College of Food Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China
| | - Yi Luo
- Department of Clinic Medicine, Xiangya School of Medicine, Central South University, Changsha 410008, China
| | - Tianyi Guo
- Hunan Provincial Key Laboratory of Grain-Oil Deep Process and Quality Control, Hunan Provincial Key Laboratory of Forestry Edible Resources Safety and Processing, Hunan Provincial Key Laboratory of Processed Food for Special Medical Purpose, College of Food Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China
| | - Qi Wu
- Hunan Provincial Key Laboratory of Grain-Oil Deep Process and Quality Control, Hunan Provincial Key Laboratory of Forestry Edible Resources Safety and Processing, Hunan Provincial Key Laboratory of Processed Food for Special Medical Purpose, College of Food Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China
| | - Feijun Luo
- Hunan Provincial Key Laboratory of Grain-Oil Deep Process and Quality Control, Hunan Provincial Key Laboratory of Forestry Edible Resources Safety and Processing, Hunan Provincial Key Laboratory of Processed Food for Special Medical Purpose, College of Food Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China
- Correspondence:
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Simcox J, Lamming DW. The central moTOR of metabolism. Dev Cell 2022; 57:691-706. [PMID: 35316619 PMCID: PMC9004513 DOI: 10.1016/j.devcel.2022.02.024] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 02/20/2022] [Accepted: 02/24/2022] [Indexed: 12/21/2022]
Abstract
The protein kinase mechanistic target of rapamycin (mTOR) functions as a central regulator of metabolism, integrating diverse nutritional and hormonal cues to control anabolic processes, organismal physiology, and even aging. This review discusses the current state of knowledge regarding the regulation of mTOR signaling and the metabolic regulation of the four macromolecular building blocks of the cell: carbohydrate, nucleic acid, lipid, and protein by mTOR. We review the role of mTOR in the control of organismal physiology and aging through its action in key tissues and discuss the potential for clinical translation of mTOR inhibition for the treatment and prevention of diseases of aging.
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Affiliation(s)
- Judith Simcox
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA.
| | - Dudley W Lamming
- William S. Middleton Memorial Veterans Hospital, Madison, WI, USA; Department of Medicine, University of Wisconsin-Madison, Madison, WI, USA.
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