Melatonin reverses H₂O₂‐induced premature senescence in mesenchymal stem cells via the SIRT1‐dependent pathway

Abstract

Mesenchymal stem cells (MSCs) represent an attractive source for stem cell-based regenerative therapy, but they are vulnerable to oxidative stress-induced premature senescence in pathological conditions. We previously reported antioxidant and antiarthritic effects of melatonin on MSCs against proinflammatory cytokines. In this study, we hypothesized that melatonin could protect MSCs from premature senescence induced by hydrogen peroxide (H2O2) via the silent information regulator type 1 (SIRT1)-dependent pathway. In response to H2O2 at a sublethal concentration of 200 μM, human bone marrow-derived MSCs (BM-MSCs) underwent growth arrest and cellular senescence. Treatment with melatonin before H2O2 exposure cannot significantly prevent premature senescence; however, treatment with melatonin subsequent to H2O2 exposure successfully reversed the senescent phenotypes of BM-MSCs in a dose-dependent manner. This result was made evident by improved cell proliferation, decreased senescence-associated β-galactosidase activity, and the improved entry of proliferating cells into the S phase. In addition, treatment with 100 μM melatonin restored the osteogenic differentiation potential of BM-MSCs that was inhibited by H2O2-induced premature senescence. We also found that melatonin attenuated H2O2-stimulated phosphorylation of p38 mitogen-activated protein kinase, decreased expression of the senescence-associated protein p16INK4α, and increased SIRT1. Further molecular experiments revealed that luzindole, a nonselective antagonist of melatonin receptors, blocked melatonin-mediated anti-senescence effects. Inhibition of SIRT1 by sirtinol counteracted the protective effects of melatonin, suggesting that melatonin reversed senescence in cells through the SIRT1-dependent pathway. Together, these findings lay new ground for understanding oxidative stress-induced premature senescence and open perspectives for therapeutic applications of melatonin in stem cell-based regenerative medicine.

Spontaneous up‐regulation of SIRT1 during osteogenesis contributes to stem cells’ resistance to oxidative stress

“…In the present study, we found that low doses of H 2 O 2 barely affected MSC viability; however, high doses of H 2 O 2 , such as 200 or 400 µM, significantly suppressed MSC proliferation and even caused cell death. These findings are in agreement with previous reports in which oxidative stress was shown to activate MSCs’ apoptotic signaling pathways . In the following osteogenic induction experiments, only moderate doses of H 2 O 2 , ranging from 25 to 100 µM, were chosen in order to minimize the influence of high doses on MSC survival.…”

Melatonin regulates the activities of ovary and delays the fertility decline in female animals via MT1/AMPK pathway

“…In type 2 diabetic rats, SIRT1 inhibitor, sirtinol, also impaired the protective effect of melatonin on sepsis‐induced brain injury . The similar result was observed that sirtinol blocked the beneficial effects of melatonin on H 2 O 2 ‐mediated cell death and accelerated senescence in both skin keratinocytes and mesenchymal stem cells . It seems that melatonin is a primary regulator of SIRT1.…”

Melatonin Treatment Improves Mesenchymal Stem Cells Therapy by Preserving Stemness during Long-term In Vitro Expansion

“…Low-dose melatonin treatment did not affect the function of BMMSCs at early passage, whereas efficiently prevented the loss of stemness of BMMSCs during long-term in vitro expansion. The notion that melatonin functions as a protector was supported by recent studies 45, 61. It might explain the question why melatonin treatment improves MSCs cell therapy for various diseases.…”