Wounds are soft tissue injuries, which are difficult to heal and can easily lead to other skin diseases. Bone marrow mesenchymal stem cells (BMSCs) and the secreted exosomes play a key role in skin wound healing. This study aims to clarify the effects and mechanisms of exosomes derived from BMSCs in wound healing. Exosomes were extracted from the supernatant of the BMSCs. The expression of the micro-RNA miR-93-3p was determined by qRT-PCR analysis. HaCaT cells were exposed to hydrogen peroxide (H 2 O 2 ) to establish a skin lesion model. MTT, flow cytometry, and transwell assays were conducted to determine cellular functions. The binding relationship between miR-93-3p and apoptotic peptidase activating factor 1 (APAF1) was measured using a dual luciferase reporter gene assay. The results showed that BMSC-derived exosomes or BMSC-exos promoted proliferation and migration and suppressed apoptosis in HaCaT cells damaged by H 2 O 2 . However, the depletion of miR-93-3p in BMSC-exos antagonized the effects of BMSC-exos on HaCaT cells. In addition, APAF1 was identified as a target of miR-93-3p. Overexpression of APAF1 induced the dysfunction of HaCaT cells. Collectively, the results indicate that BMSC-derived exosomes promote skin wound healing via the miR-93-3p/APAF1 axis. This finding may help establish a new therapeutic strategy for skin wound healing.

Traumas, infections, tumors, and some congenital malformations can lead to bone defects or even bone loss. The goal of the present study was to investigate whether inclusion of endothelial progenitor cells derived from peripheral blood (PB–EPCs) in cell-seeded partially deproteinized bone (PDPB) implants would stimulate recruitment of systemically injected bone marrow stromal cells (BMSCs) to the implant. Methods: BMSCs were injected intravenously with lentiviral expression vector expressing enhanced green fluorescent protein (eGFP) for tracing. Recruitment of eGFP-positive BMSCs was tested for the following implant configurations: 1) seeded with both BMSC and PB-EPC, 2) BMSC alone, 3) PB-EPC alone, and 4) unseeded PDPB. Protein and mRNA levels of endogenous stromal-derived factor-1 (SDF-1) and its receptor CXCR4, as well as monocyte chemotactic protein-1 (MCP-1) and its receptor CCR2, were evaluated on the 8th week. Immunohistochemical staining was performed to determine eGFP-positive areas at the defective sites. Masson’s trichrome staining was conducted to observe the distribution of collagen deposition and evaluate the extent of osteogenesis. Results: The mRNA and protein levels of SDF-1 and CXCR4 in the co-culture group were higher than those in other groups (p < 0.05) 8 weeks after the surgery. MCP-1 mRNA level in the co-culture group was also higher than that in the other groups (p < 0.05). Immunohistochemical assays revealed that the area covered by eGFP-positive cells was larger in the co-culture group than in the other groups (p < 0.05) after 4 weeks. Masson’s trichrome staining revealed better osteogenic potential of the co-culture group compared to the other groups (p < 0.05). Conclusion: These experiments demonstrate an association between PB-EPC and BMSC recruitment mediated by the SDF-1/CXCR4 axis that can enhance repair of bone defects.

Epithelial differentiation of adipose-derived stem cells (ADSCs) is mediated by sophisticated interactions of various molecular functions and biological processes, including transcriptional regulation. Runt-related transcription factor 2 (RUNX2) increases osteoblast and adipocyte differentiation of ADSCs. However, the role of RUNX2 in epithelial differentiation of ADSCs is unknown. We first showed that ADSCs possess the potential to differentiate into epithelial lineage. Then, we employed the effect of RUNX2 on epithelial differentiation of ADSCs. Our data showed that RUNX2 promoted epithelial differentiation of ADSCs. Overexpression or knockdown of RUNX2 resulted in increase or decrease of E-cadherin expression, respectively. Abatement of E-cadherin in ADSCs attenuated RUNX2-activated epithelial conversion of ADSCs and epithelial markers cytokeratin 18 (CK18) and zonula occludens protein-1 (ZO-1). We also evaluated the effect of RUNX2 on burn wound healing in vivo. The wound re-epithelialization were accelerated by RUNX2. The wound closure indexs, demis regeneration and revascularization were all improved. Furthermore, RUNX2 binding directly to the E-cadherin promoter region was characterized in ADSCs by chromatin immunoprecipitation (ChIP) and luciferase promoter reporter assays. Taken together, the study demonstrates the role of RUNX2 in epithelial differentiation of ADSCs and suggests that RUNX2 promotes E-cadherin expression, at least in part, through its direct binding to the promoter.

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Background Long noncoding RNAs (lncRNAs) can be used as competitive endogenous RNAs (ceRNAs) to bind to microRNAs (miRNAs) to regulate gene expression. Previous studies have demonstrated that ceRNAs play an important role in the development of tumors. However, it is not clear whether the lncRNA–miRNA–mRNA ceRNA network plays a role in androgenic alopecia (AGA). Methods The hair follicles of three AGA patients and three healthy individuals were collected for high‐throughput whole transcriptome sequencing to screen for differentially expressed lncRNAs. Differentially expressed lncRNA target genes were subjected to databases to predict miRNA–mRNA and lncRNA–miRNA relationship pairs, and a ceRNA network was constructed using Cytoscape software. Relative expression was verified by real‐time quantitative reverse transcription–polymerase chain reaction (qRT‐PCR). Results 84 lncRNAs were significantly differentially expressed between the hair follicles of AGA patients and those of healthy individuals; 30 were upregulated, and 54 were downregulated. The top 10 upregulated lncRNAs were ENST00000501520, ENST00000448179, ENST00000318291, ENST00000568280, ENST00000561121, ENST00000376609, ENST00000602414, ENST00000573866, ENST00000513358, and ENST00000564194. The top 10 downregulated lncRNAs were ENST00000566804, ENST00000561973, ENST00000587680, ENST00000569927, ENST00000340444, ENST00000424345, ENST00000589787, NR_024344, NR_073026, and NR_110001. The qRT‐PCR validation results and receiver‐operating characteristic curve analysis indicated that one upregulated lncRNA, LOXL1‐AS1 (ENST00000564194), had the most significant clinical diagnostic potential. After further analysis, it was concluded that LOXL1‐AS1 could be used as a sponge to target hsa‐miR‐5193, thereby regulating TP53 expression. Conclusion The ceRNA network‐regulating AGA was constructed through high‐throughput sequencing. Our study also identified a key lncRNA that is possibly related to the AGA pathological process.