Abstract
In obesity and diabetes, intramuscular fat (IMF) content correlates markedly with insulin sensitivity, which makes IMF manipulation an area of therapeutic interest. Melatonin, an important circadian rhythm-regulating hormone, reportedly regulates fat deposition, but its effects on different types of adipose vary. Little is known about the role of melatonin in IMF deposition. Here, using intramuscular preadipocytes in pigs, we investigated to determine whether melatonin affects or regulates IMF deposition. We found that melatonin greatly inhibited porcine intramuscular preadipocyte proliferation. Although melatonin administration significantly upregulated the expression of adipogenic genes, smaller lipid droplets were formed in intramuscular adipocytes. Additional investigation demonstrated that melatonin promoted lipolysis of IMF by activating protein kinase A and the signaling of ERK1/2. Moreover, melatonin increased thermogenesis in intramuscular adipocytes by enhancing mitochondrial biogenesis and mitochondrial respiration. A mouse model, in which untreated controls were compared with mice that received 3 weeks of melatonin treatment, verified the effect of melatonin on IMF deposition. In conclusion, melatonin reduces IMF deposition by upregulating lipolysis and mitochondrial bioactivities. These data establish a link between melatonin signaling and lipid metabolism in mammalian models and suggest the potential for melatonin administration to treat or prevent obesity and related diseases.
Highlights
IntroductionIntramuscular fat (IMF) content correlates markedly with insulin sensitivity, which makes intramuscular fat (IMF) manipulation an area of therapeutic interest
In obesity and diabetes, intramuscular fat (IMF) content correlates markedly with insulin sensitivity, which makes IMF manipulation an area of therapeutic interest
After treating intramuscular preadipocytes with 1 mM of melatonin for 24 h, we found that the proportion of EdU-positive cells decreased by 80% (Fig. 1B, C), and no significant apoptotic cells were found by flow cytometry tests (Fig. 1D, E)
Summary
Intramuscular fat (IMF) content correlates markedly with insulin sensitivity, which makes IMF manipulation an area of therapeutic interest. Melatonin reduces IMF deposition by upregulating lipolysis and mitochondrial bioactivities These data establish a link between melatonin signaling and lipid metabolism in mammalian models and suggest the potential for melatonin administration to treat or prevent obesity and related diseases.—Liu, K., W. Melatonin reduces intramuscular fat deposition by promoting lipolysis and increasing mitochondrial function. Alonso-Vale et al [12] reported that melatonin inhibited adipocyte differentiation through regulated C/EBP transcriptional activity This inconsistency in findings may be due to the differences in the timing of melatonin treatment of 3T3-L1 cells. Recent findings indicate that melatonin promotes the differentiation of bovine intramuscular preadipocytes into adipocytes by increasing the expression levels of PPAR , C/EBP , and C/EBP via melatonin receptor 1B (MT2) [14], laboratory experiments demonstrate that
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
