The role of skeletal muscle in nonshivering thermogenesis (NST) is not well understood. Here we show that sarcolipin (Sln), a newly identified regulator of the sarco/endoplasmic reticulum Ca(2+)-ATPase (Serca) pump, is necessary for muscle-based thermogenesis. When challenged to acute cold (4 °C), Sln(-/-) mice were not able to maintain their core body temperature (37 °C) and developed hypothermia. Surgical ablation of brown adipose tissue and functional knockdown of Ucp1 allowed us to highlight the role of muscle in NST. Overexpression of Sln in the Sln-null background fully restored muscle-based thermogenesis, suggesting that Sln is the basis for Serca-mediated heat production. We show that ryanodine receptor 1 (Ryr1)-mediated Ca(2+) leak is an important mechanism for Serca-activated heat generation. Here we present data to suggest that Sln can continue to interact with Serca in the presence of Ca(2+), which can promote uncoupling of the Serca pump and cause futile cycling. We further show that loss of Sln predisposes mice to diet-induced obesity, which suggests that Sln-mediated NST is recruited during metabolic overload. These data collectively suggest that SLN is an important mediator of muscle thermogenesis and whole-body energy metabolism.
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http://dx.doi.org/10.1038/nm.2897 | DOI Listing |
Annu Rev Physiol
September 2025
2Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Science, School of Agriculture, Biomedicine and Environment, La Trobe University, Melbourne, Victoria, Australia; email:
For physiological processes in the vital organs of eutherian mammals to function, it is important to maintain constant core body temperature at ∼37°C. Mammals generate heat internally by thermogenesis. The focus of this review is on heat generated in resting skeletal muscles, using the same cellular components that muscles use to regulate cytoplasmic calcium concentrations [Ca2+] and contraction.
View Article and Find Full Text PDFBiomed Pharmacother
March 2024
Department of Pharmacology, BioHealth Institute Granada (IBs Granada), Neuroscience Institute (CIBM), School of Medicine, University of Granada, Granada 18016, Spain. Electronic address:
Melatonin acute treatment limits obesity of young Zücker diabetic fatty (ZDF) rats by non-shivering thermogenesis (NST). We recently showed melatonin chronically increases the oxidative status of vastus lateralis (VL) in both obese and lean adult male animals. The identification of VL skeletal muscle-based NST by uncoupling of sarcoendoplasmic reticulum Ca-ATPase (SERCA)- sarcolipin (SLN) prompted us to investigate whether melatonin is a SERCA-SLN calcium futile cycle uncoupling and mitochondrial biogenesis enhancer.
View Article and Find Full Text PDFAm J Physiol Cell Physiol
March 2024
Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada.
Dysregulation of skeletal muscle morphology and metabolism is associated with chronic diseases such as obesity and type 2 diabetes. The enzyme glycogen synthase kinase 3 (GSK3) is highly involved in skeletal muscle physiology and metabolism, acting as a negative regulator of muscle size, strength, adaptive thermogenesis, and glucose homeostasis. Correspondingly, we have shown that partial knockdown (∼40%) of GSK3 specifically in skeletal muscle increases lean mass, reduces fat mass, and activates muscle-based adaptive thermogenesis via sarco(endo)plasmic reticulum Ca (SERCA) uncoupling in male mice.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2023
School of Biomedical Sciences, The University of Queensland, Brisbane, QLD 4072, Australia.
Resting skeletal muscle generates heat for endothermy in mammals but not amphibians, while both use the same Ca-handling proteins and membrane structures to conduct excitation-contraction coupling apart from having different ryanodine receptor (RyR) isoforms for Ca release. The sarcoplasmic reticulum (SR) generates heat following Adenosine triphosphate (ATP) hydrolysis at the Ca pump, which is amplified by increasing RyR1 Ca leak in mammals, subsequently increasing cytoplasmic [Ca] ([Ca]). For thermogenesis to be functional, rising [Ca] must not interfere with cytoplasmic effectors of the sympathetic nervous system (SNS) that likely increase RyR1 Ca leak; nor should it compromise the muscle remaining relaxed.
View Article and Find Full Text PDFInt J Mol Sci
December 2022
State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.
Skeletal muscle-based nonshivering thermogenesis (NST) plays an important role in the regulation and maintenance of body temperature in birds and large mammals, which do not contain brown adipose tissue (BAT). However, the relative contribution of muscle-based NST to thermoregulation is not clearly elucidated in wild small mammals, which have evolved an obligate thermogenic organ of BAT. In this study, we investigated whether muscle would become an important site of NST when BAT function is conditionally minimized in Brandt's voles ().
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