Melatonin enhances the human mesenchymal stem cells motility via melatonin receptor 2 coupling with Gαq in skin wound healing

Abstract

Melatonin, a circadian rhythm-promoting molecule, has a variety of biological functions, but the functional role of melatonin in the motility of mesenchymal stem cells (MSCs) has yet to be studied. In a mouse skin excisional wound model, we found that transplantation of umbilical cord blood (UCB)-MSCs pretreated with melatonin enhanced wound closure, granulation, and re-epithelialization at mouse skin wound sites, where relatively more UCB-MSCs which were engrafted onto the wound site were detected. Thus, we identified the signaling pathway of melatonin, which affects the motility of UCB-MSCs. Melatonin (1 μm) significantly increased the motility of UCB-MSCs, which had been inhibited by the knockdown of melatonin receptor 2 (MT2). We found that Gαq coupled with MT2 and that the binding of Gαq to MT2 uniquely stimulated an atypical PKC isoform, PKCζ. Melatonin induced the phosphorylation of FAK and paxillin, which were concurrently downregulated by blocking of the PKC activity. Melatonin increased the levels of active Cdc42 and Arp2/3, and it has the ability to stimulate cytoskeletal reorganization-related proteins such as profilin-1, cofilin-1, and F-actin in UCB-MSCs. Finally, a lack of MT2 expression in UCB-MSCs during a mouse skin transplantation experiment resulted in impaired wound healing and less engraftment of stem cells at the wound site. These results demonstrate that melatonin signaling via MT2 triggers FAK/paxillin phosphorylation to stimulate reorganization of the actin cytoskeleton, which is responsible for Cdc42/Arp2/3 activation to promote UCB-MSCs motility.

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

“…Melatonin treatment has also been applied in osteoporosis treatment partly by promoting osteogenic differentiation of BMMSCs 39, 59. In these studies, the application of melatonin aimed to promote the function of MSCs and focused on the effect of melatonin on normal MSCs 37, 38, 40-44, 60. However, in our study, we found low-concentration melatonin functioned as a protector but not as a regulator for BMMSCs.…”

“…Lee and colleagues showed that melatonin treatment improves the mobility of umbilical cord blood-derived MSCs to improve skin wound healing 44. Three research groups reported that melatonin treatment improves adipose-derived MSCs therapy for acute lung ischemia-reperfusion injury 43, sepsis-induced kidney injury 42, and acute interstitial cystitis 58.…”

“…Emerging evidences showed that melatonin regulates several characteristics of MSCs in vitro 37-40. Melatonin treatment has been reported to promote osteogenic differentiation, vitality, and mobility of MSCs, resulting in improved MSCs therapy of skeletal defect 41, sepsis-induced kidney injury 42, acute lung ischemia-reperfusion injury 43 and skin wound healing 44. Recently, Zhou and colleagues showed that melatonin treatment prevents H 2 O 2 -induced premature senescence of MSCs 45, suggesting melatonin is a promising candidate to optimize in vitro MSCs expansion.…”

Exogenous melatonin inhibits neutrophil migration through suppression of ERK activation

“…As the major output of the pineal gland in vertebrates, melatonin plays a vital homeostatic role in the rhythm-dependent basic functions of zebrafish physiology, including sleep (Zhdanova 2011, Elbaz et al 2013, diet (Lima-Cabello et al 2014), development (Kazimi & Cahill 1999, de Borsetti et allearning and memory (Baydas et al 2005, Moriya et al 2007. Almost all of the functional actions of the melatonin system are conducted through the identified receptor 1, 2, or 3 (Fusani & Gahr 2014, Kleber et al 2014, Lee et al 2014. In zebrafish, melatonin and its receptors become functional at w20 h post-fertilization (Danilova et al 2004).…”

Vibrio vulnificus VvpE Stimulates IL-1β Production by the Hypomethylation of the IL-1β Promoter and NF-κB Activation via Lipid Raft–Dependent ANXA2 Recruitment and Reactive Oxygen Species Signaling in Intestinal Epithelial Cells

“…The samples were incubated for 4 h, mixed with protein A/G Plus-agarose immunoprecipitation reagent (Pierce, Rockford, IL) and then incubated for an additional 12 h. The beads were washed four times and the bound proteins were released from the beads by boiling in SDS-PAGE sample buffer for 5 min. Samples were analyzed by Western blotting, which was performed as previously described with minor modifications (27).…”