Effects of melatonin on the proliferation and differentiation of rat adipose-derived stem cells

Abstract

Background: Osteogenesis driven by adipose-derived stem cells (ADSCs) is regulated by physiological and pathological factors. Accumulating evidence from in vitro and in vivo experiments suggests that melatonin may have an influence on bone formation. However, little is known about the effects of melatonin on osteogenesis, which thus remains to be elucidated. This study was performed to determine whether melatonin at physiological concentrations (0.01-10 nM) could affect the in vitro proliferation and osteogenic differentiation of rat ADSCs.Materials and Methods: ADSCs were isolated from the fat of adult rats. After cell expansion in culture media and through three passages, osteogenesis was induced in a monolayer culture using osteogenic medium with or without melatonin at physiological concentrations (0.01-10 nM). After four weeks, the cultures were examined for mineralization by Alizarin Red S and von Kossa staining and for alkaline phosphatase (ALP) activity using an ALP kit. Cell viability and apoptosis were also assayed by 3-(4, 5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTT) assay and flow cytometry, respectively.Results: The results indicated that at physiological concentrations, melatonin suppressed proliferation and differentiation of ADSCs. These data indicate that ADSCs exposed to melatonin, had a lower ALP activity in contrast to the cells exposed to osteogenic medium alone. Similarly, mineral deposition (calcium level) also decreased in the presence of melatonin. Flow cytometry confirmed that cell growth had decreased and that the numbers of apoptotic cells had increased.Conclusion: These results suggest that the physiological concentration of melatonin has a negative effect on ADSC osteogenesis.

Melatonin Regulates Differentiation of Sheep Brown Adipocyte Precursor Cells Via AMP-Activated Protein Kinase

“…Therefore, perirenal brown adipocyte precursor cells isolated from day 90 of gestation were used to evaluate the effect of melatonin on sheep brown adipogenesis. Despite that numerous previous studies demonstrate that melatonin affects cell proliferation, the effect of suppression or stimulation varies, depending on the cell type examined and melatonin's concentration (23). In the present study, melatonin exhibited an antiproliferative effect on sheep brown preadipocytes, which might be attributed to melatonin's effects on PCNA, a standard marker of cell proliferation (24).…”

Melatonin and the theories of aging: a critical appraisal of melatonin's role in antiaging mechanisms

“…Notably, this osteogenic property of melatonin is associated with the suppression of the alternate differentiation route toward adipocytes . However, melatonin has been reported to inhibit osteogenesis in adipose‐tissue‐derived stem cells from rats , a finding that indicates a difference to MSCs regarding the expression of differentiation determinants. Studies on the differentiation of 3T3‐L1 preadipocytes to adipocytes have led to divergent results.…”

Inter‐relationships of the chronobiotic, melatonin, with leptin and adiponectin: implications for obesity

“…The major source of leptin is mature adipocytes, so melatonin‐dependent decreases in leptin levels may be basically the result of body weight loss rather than the improvement of leptin function. Additionally, this effect may be due to the ability of melatonin to suppress the proliferation and differentiation of pre‐adipocytes .…”