RESUMO
The aim of the present study was to investigate the effect and mechanism of action of microRNA (miR)-27b on skin wound healing in rats with deep second-degree scald burns and in BJ human skin fibroblast cells. Rat models with deep second-degree scald burns were constructed and injected with miR-27b mimics and inhibitors at the wound site daily for 21 days. Healing of burned skin tissues was observed at 0, 3, 7, 14 and 21 days following modeling. H&E and Masson staining were used to observe the pathological structure and degree of collagen fibers in the burned skin tissues. The effects of miR-27b on BJ cell proliferation and migration were determined by MTT and scratch assays. Matrix metalloproteinase-1 (MMP-1), α-smooth muscle actin (α-SMA), collagen I and collagen III expression in rat skin tissues and BJ cells were measured via reverse transcription-quantitative PCR and western blot analysis. The results of the in vivo experiments demonstrated that miR-27b inhibition accelerated scalded skin healing and induced fibroblast growth. Furthermore, the in vitro experiments revealed that miR-27b inhibition increased BJ cell proliferation and migration. Furthermore, miR-27b inhibition upregulated MMP-1, α-SMA, collagen I and collagen III expression in the skin tissues and cells, while the overexpression of miR-27b demonstrated the opposite effect. In conclusion, the results of the present study revealed that miR-27b inhibition increased fibroblast proliferation, thereby accelerating scald wound healing in rats.
RESUMO
In this study, the effects of miR-27b on angiogenesis in skin repair procedure in rats with deep II degree scald were explored. The rat model of deep II scald was established. miR-27b mimics and inhibitor were injected daily at the wound site for 3 weeks. The healing of scald was observed at 0, 3, 7, 14, and 21 days after the model was established, and the pathological changes of skin were observed by HE and Masson's trichrome stains. Skin tissues were taken 14 days after the operation; CD31 and Ki-67 immunohistochemistry was exerted to evaluate neovascularization and proliferation. Human microvascular endothelial cells (HMEC-1) cells were cultured in vitro. miR-27b mimics or inhibitor was transfected to construct over-expression or inhibition cell lines. MTT assay, scratch test, and angiogenesis test were used to evaluate cell proliferation, migration, and vascular regeneration. Finally, RT-PCR and Western blot were exerted to determine the expression of vascular endothelial growth factor C (VEGF-C), epidermal growth factor (EGF) mRNAs, and protein, respectively. Control, inhibitor, mi-NC, VEGF-C, inhibitor + si-NC, and inhibitor + VEGF-C siRNA groups were used to further analyze the mechanism of miR-27b on VEGF-C; the above experiments were repeated. In contrast to model group, miR-27b inhibitor could significantly promote the healing of scalded skin, alleviate the pathological status of scalded, and promote the angiogenesis and proliferation (p < 0.05). In vitro, miR-27b inhibitor evidently promoted cell proliferation, migration, and angiogenesis and increased the expression of VEGF-C, EGF genes, and protein, while miR-27b mimics significantly reversed the above trends. Further studies shown that downregulation of miR-27b expression can promote the proliferation, migration, and angiogenesis of HMEC-1 cells by promoting the expression of VEGF-C. miR-27b promotes angiogenesis and skin repair in scalded rats through regulating VEGF-C expression.
Assuntos
Queimaduras/genética , Queimaduras/patologia , Regulação da Expressão Gênica , MicroRNAs/metabolismo , Neovascularização Fisiológica/genética , Pele/patologia , Fator C de Crescimento do Endotélio Vascular/genética , Cicatrização , Animais , Sequência de Bases , Movimento Celular/genética , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Colágeno/metabolismo , Modelos Animais de Doenças , Regulação para Baixo , Células Endoteliais/metabolismo , Fator de Crescimento Epidérmico/metabolismo , Humanos , Antígeno Ki-67/metabolismo , Masculino , MicroRNAs/genética , Microvasos/patologia , Ratos Sprague-Dawley , Fator C de Crescimento do Endotélio Vascular/metabolismo , Cicatrização/genéticaRESUMO
To study the effects of mir-27b on angiogenesis and fibroblast activation and to explore its further mechanism. Humanmicrovascular endothelial cell (HMEC)-1 and humannormal skin fibroblast (BJ) cells were treated with mir-27b inhibitor negative control reagent, mir-27b inhibitor, LY294002, and mir-27b inhibitor + LY294002, respectively. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) was used to detect the T-cell proliferation. The migration ability was detected by Scratch assays. The angiogenesis of HMEC-1 cells was observed by in vitro tube formation assay. The mRNA and protein expression of vascular endothelial growth factor (VEGF) in HMEC-1 cells and the mRNA and protein expression of collagen I, collagen III, α-SMA, and MMP1 in BJ cells were detected by quantitativereal-time polymerase chain reaction (qRT-PCR) and Western blot, respectively. Meanwhile, the PI3K/protein kinase B (AKT) pathway-related proteins were also detected by Western blot. The proliferation, migration, angiogenesis, the mRNA and protein expression of VEGF and the protein expression of p-PI3K and p-AKT in HMEC-1 cells were increased after treated with mir-27b inhibitor. Meanwhile, the proliferation, migration, and the protein expression of collagen I, collagen III, α-SMA, MMP1, p-PI3K, and p-AKT in BJ cells were increased after treated with mir-27b inhibitor. However, the angiogenesis and fibroblast activation of mir-27b inhibitor was reversed by LY294002, and the activate effect to PI3K/AKT pathway was also inhibited. Down-regulation of mir-27b could promote angiogenesis and fibroblast activation, and its mechanism is related to activate PI3K/AKT signaling pathway.