RESUMEN
The current treatment of skin fibrosis is limited in its effectiveness due to a lack of understanding of the underlying mechanisms. Previous research has shown a connection between microRNAs (miRNAs) and the development of skin fibrosis. Therefore, investigating miRNA for the treatment of skin fibrotic diseases is highly important and merits further exploration. In this study, we have discovered that let-7f-5p could suppress the proliferation, migration, and expression of collagen type I alpha 1 (COL1A1) in human dermal fibroblasts (HDFs). It was further determined that let-7f-5p could target thrombospondin-1 (THBS1), thereby inhibiting the TGF-ß2/Smad3 signaling pathway and exerting its biological effects. Additionally, let-7f-5p is regulated by Hsa_circ_0000437, which acts as a sponge molecule for let-7f-5p and consequently regulates the biological function of HDFs. Furthermore, our findings indicate that in vivo overexpression of let-7f-5p leads to a reduction in dermal thickness and COL1A1 expression, effectively inhibiting the progression of bleomycin (BLM)-induced skin fibrosis in mice. Hence, our research enhances the comprehension of the Hsa_circ_0000437/let-7f-5p/THBS1/TGF-ß2/Smad3 regulatory network, highlighting the potential of let-7f-5p as a therapeutic approach for the treatment of skin fibrosis.
Asunto(s)
Bleomicina , Cadena alfa 1 del Colágeno Tipo I , Colágeno Tipo I , Fibroblastos , Fibrosis , MicroARNs , Proteína smad3 , MicroARNs/genética , MicroARNs/metabolismo , Bleomicina/efectos adversos , Humanos , Animales , Ratones , Fibroblastos/metabolismo , Colágeno Tipo I/metabolismo , Colágeno Tipo I/genética , Cadena alfa 1 del Colágeno Tipo I/metabolismo , Cadena alfa 1 del Colágeno Tipo I/genética , Proteína smad3/metabolismo , Proteína smad3/genética , Proliferación Celular , ARN Circular/genética , ARN Circular/metabolismo , Transducción de Señal/efectos de los fármacos , Factor de Crecimiento Transformador beta2/metabolismo , Factor de Crecimiento Transformador beta2/genética , Trombospondina 1/metabolismo , Trombospondina 1/genética , Piel/metabolismo , Piel/patología , Movimiento Celular/efectos de los fármacos , Enfermedades de la Piel/inducido químicamente , Enfermedades de la Piel/genética , Enfermedades de la Piel/metabolismo , Enfermedades de la Piel/patología , Enfermedades de la Piel/tratamiento farmacológico , Regulación de la Expresión Génica/efectos de los fármacosRESUMEN
BACKGROUND: The use of keratinocytes derived from induced pluripotent stem cells (iPSCs-KCs) may represent a novel cell therapy strategy for burn treatment. There is growing evidence that extracellular vesicles, including exosomes, are primary mediators of the benefits of stem cell therapy. Herein, we thus explored the effects of exosomes produced by iPSCs-derived keratinocytes (iPSCs-KCs-Exos) in a model of deep second-degree burn wound healing and evaluated the mechanistic basis for the observed activity. METHODS: iPSCs-KCs-Exos were isolated from conditioned medium of iPSCs-KCs and verified by electron micrograph and size distribution. Next, iPSCs-KCs-Exos were injected subcutaneously around wound sites, and its efficacy was evaluated by measuring wound closure areas, histological examination, and immunohistochemistry staining. The effects of iPSCs-KCs-Exos on proliferation and migration of keratinocytes and endothelial cells in vitro were assessed by EdU staining, wound healing assays, and transwell assay. Then, high-throughput microRNA sequencing was used to explore the underlying mechanisms. We assessed the roles of miR-762 in iPSCs-KCs-Exos-induced regulation of keratinocytes and endothelial cells migration. Furthermore, the target gene which mediated the biological effects of miR-762 in keratinocytes and endothelial cells was also been detected. RESULTS: The analysis revealed that iPSCs-KCs-Exos application to the burn wound drove the acceleration of wound closure, with more robust angiogenesis and re-epithelialization being evident. Such iPSCs-KCs-Exos treatment effectively enhanced endothelial cell and keratinocyte migration in vitro. Moreover, the enrichment of miR-762 was detected in iPSCs-KCs-Exos and was found to target promyelocytic leukemia (PML) as a means of regulating cell migration through a mechanism tie to integrin beta1 (ITGB1). CONCLUSION: These results thus provide a foundation for the further study of iPSCs-KCs-Exos as novel cell-free treatments for deep second-degree burns.