miR-100-5p Promotes Epidermal Stem Cell Proliferation through Targeting MTMR3 to Activate PIP3/AKT and ERK Signaling Pathways

Abstract

Skin epidermal stem cells (EpSCs) play a critical role in wound healing and are ideal seed cells for skin tissue engineering. Exosomes from human adipose-derived stem cells (ADSC-Exos) promote human EpSC proliferation, but the underlying mechanism remains unclear. Here, we investigated the effect of miR-100-5p, one of the most abundant miRNAs in ADSC-Exos, on the proliferation of human EpSCs and explored the mechanisms involved. MTT and BrdU incorporation assays showed that miR-100-5p mimic transfection promoted EpSC proliferation in a time-dependent manner. Cell cycle analysis showed that miR-100-5p mimic transfection significantly decreased the percentage of cells in the G1 phase and increased the percentage of cells in the G2/M phase. Myotubularin-related protein 3 (MTMR3), a lipid phosphatase, was identified as a direct target of miR-100-5p. Knockdown of MTMR3 in EpSCs by RNA interference significantly enhanced cell proliferation, decreased the percentage of cells in the G1 phase and increased the percentage of cells in the S phase. Overexpression of MTMR3 reversed the proproliferative effect of miR-100-5p on EpSCs, indicating that miR-100-5p promoted EpSC proliferation by downregulating MTMR3. Mechanistic studies showed that transfection of EpSCs with miR-100-5p mimics elevated the intracellular PIP3 level, induced AKT and ERK phosphorylation, and upregulated cyclin D1, E1, and A2 expression, which could be attenuated by MTMR3 overexpression. Consistently, intradermal injection of ADSC-Exos or miR-100-5p-enriched ADSC-Exos into cultured human skin tissues significantly reduced MTMR3 expression and increased the thickness of the epidermis and the number of EpSCs in the basal layer of the epidermis. The aforementioned effect of miR-100-5p-enriched ADSC-Exos was stronger than that of ADSC-Exos and was reversed by MTMR3 overexpression. Collectively, our findings indicate that miR-100-5p promotes EpSC proliferation through MTMR3-mediated elevation of PIP3 and activation of AKT and ERK. miR-100-5p-enriched ADSC-Exos can be used to treat skin wound and expand EpSCs for generating epidermal autografts and engineered skin equivalents.

Leptin Promotes the Proliferation and Neuronal Differentiation of Neural Stem Cells through the Cooperative Action of MAPK/ERK1/2, JAK2/STAT3 and PI3K/AKT Signaling Pathways

“…Leptin induces proliferation and (or) anti-apoptosis effect of breast cancer cells and vascular smooth muscle cells by activating the PI3K pathway [44,45]. The ERK1/2 pathway has also been shown to play an important role in regulating the proliferation of a variety of stem cells [46][47][48]. In this study, it was found that leptin-induced NSCs proliferation was accompanied by an increase in phosphorylation of AKT and ERK1/2.…”

The Upregulation of Regenerative Activity for Extracellular Vesicles with Melatonin Modulation in Chemically Defined Media

“…The paracrine effects of EVs on cells regulate a broad range of functions, and they occur through the transportation of genetic materials, including mRNAs and miRNAs [ 25 ]. Three types of miRNAs, such as let-7b-5p, miR-23a-3p, and miR-100-5p, have been demonstrated to control regeneration-related processes, including angiogenesis, cell proliferation, migration, and others [ 26 , 27 , 28 ], and exert superior regeneration effects on the kidney [ 17 ], bone [ 29 ], and cartilage [ 30 ], respectively. We selected these miRNAs as some of the representative miRNAs used for regenerations, and quantitatively compared the expression levels of them in STV EVs, STV mEVs, CDM EVs, and CDM mEVs.…”

Angiopoietin-like 4 promotes the proliferation and migration of epidermal stem cells and contributes to the re-epithelialization of cutaneous wounds

“…EpSCs were isolated from the skin of newborn mice as previously described [13, 14]. Briefly, skin tissues were collected from anesthetized mice, cut into 1.0×1.0 cm 2 pieces, and incubated in Dispase II (0.25%, Sigma, St Louis, USA) for 16-18 h at 4[.…”

“…MTT and BrdU incorporation assays were performed to measure the proliferation of EpSCs as previously described [13,14]. Optical density values were measured at 490 nm for MTT assay and at 450 nm for BrdU incorporation assay, using the Multiskan TM Spectrum Microplate Reader (Thermo Fisher, Massachusetts, USA).…”