Effect of all-trans-retinoic acid on the proliferation and expression of α-SMA in human embryonic lung fibroblasts

AIM: To investigate the effects of all-trans-retinoic acid (ATRA) on the proliferation and differentiation of transforming growth factor β₁(TGF-β₁)-stimulated human embryonic lung fibroblasts (HFL-I).METHODS: The HFL-I cells were cultured in vitro and were pretreated with ATRA for 3 days at the concentrations of 0.1 μmol/L, 1 μmol/L and 10 μmol/L. The proliferation of HFL-1 cells was detected by MTT method. The mRNA expression of α-smooth muscle actin(α-SMA) in HFL-I cells stimulated with TGF-β₁ for 0 h, 6 h, 12 h, 24 h, 48 h and 72 h was detected by RT-PCR and the protein expression of α-SMA at the time points of 1,3 and 5 days was detected by Western blotting. The mRNA expression of α-SMA in HFL-I cells pretreated with different concentrations of ATRA for 24 h was detected the by RT-PCR and the protein expression at time point of 3rd day was detected by Western blotting. RESULTS: Different concentration of ATRA inhibited the proliferation of HFL-I in a dose-dependent manner (P<0.05). Both mRNA and protein expression of α-SMA in HFL-I cells pretreated with TGF-β₁ was up-regulated (P<0.05). ATRA down-regulated the mRNA and protein expression of α-SMA induced by TGF-β₁ in a dose-dependent manner (P<0.05). CONCLUSION: ATRA inhibits the proliferation and TGF-β₁-stimulated differentiation in HFL-I cells by down-regulating the mRNA and protein expression of α-SMA.     

Molecular and ultrastructural studies of the fibrotic lesions of bovine focal proliferative fibrogranulomatous panniculitis (Lechiguana)

This work aimed to investigate some aspects related to the pathogenicity of Lechiguana, a bovine fibroproliferative lesion characterized by rapid collagen accumulation. Light and transmission electron microscopy and in situ hybridization studies were performed in order to elucidate the fibrogenic activity of this lesion. The characterization of fibroblastic plasticity in the lesion was done by immunohistochemical study for α-smooth-muscle cell actin. The ovoid-shaped cells presented positive reaction for α-smooth-muscle cell actin in their cytoplasm and, at the electron-microscopic level demonstrated basal lamina-like material adjacent to the external surface and collagen fibrils that corresponded to a cell population phenotypically similar to the myofibroblast. We also investigated α1 collagen type I mRNA at different times of evolution of Lechiguana lesions, using isotopic and non-isotopic in situ hybridization. The results strongly suggest the involvement of a myofibroblast-like cell population that expresses mRNA for type I collagen and is probably associated with the increase of collagen deposition.     

山羊创伤愈合时组织病理学和超微结构的观察

山羊创伤愈合过程组织病理学和超微结构的动态变化观察结果表明:在几天内伤口中出现许多肌-成纤维细胞,它具有成纤维细胞和平滑肌细胞的共同特征。肌-成纤维细胞的核细长,有深的缺刻,并有发育完善的高尔基体和粗面内质网以及在胞浆中有很多微丝团块等。所以,肌-成纤维细胞在创伤收缩中起重要作用。     

乳牛创伤愈合过程的动态变化与创伤收缩机理的研究

本研究从显微与超微结构的角度,观察了参与创伤愈合过程的细胞种类和结构的变化,发现创伤愈合过程有四个组成部分:①炎症反应②细胞增殖③创伤收缩(Wound contraction,WC)④创伤改建;肌成纤维细胞(Myofiroblast,MFB)的收缩是创伤收缩(WC)的动力来源,其结构和功能介于平滑肌细胞和成纤维细胞之间。     

miR-129-3p targets Smad3 to inhibit viability and migration of NIH3T3 cells during TGF-β-induced transformation into myofibroblasts

AIM: To explore the effects of microRNA-129-3p (miR-129-3p) on the viability and migration of NIH3T3 cells during transforming growth factor-β (TGF-β)-induced transformation into myofibroblasts and the underlying molecular mechanisms. METHODS: RT-qPCR was used to examine the relative expression of miR-129-3p in renal cell carcinoma (RCC)-adjacent tissues and fibrotic renal tissue. NIH3T3 cells were stimulated with TGF-β to transform into myofibroblasts, and miR-129-3p expression level was detected. After transfection with miR-129-3p mimics for 48 h in vitro, the cell viability was measured by MTT assay, the protein expression level of Ki-67 was determined by Western blot, and the cell migration was observed by wound healing assay. The direct target of miR-129-3p was predicted by online database TargetScan and confirmed by dual-luciferase reporter assay. The expression level of target protein was further confirmed by Western blot. RESULTS: Compared with the RCC-adjacent tissues, the expression of miR-129-3p was down-regulated in fibrotic renal tissue (P<0.01). In TGF-β-induced NIH3T3 cell transformation into myofibroblasts, the expression of miR-129-3p was also decreased (P<0.01). Transfection with miR-129-3p mimics followed by TGF-β stimulation in the NIH3T3 cells inhibited the viability, Ki-67 expression and migration. TargetScan analysis showed miR-129-3p had binding sites in the 3'-UTR of Smad3, which was confirmed by dual-luciferase reporter assay. The results of Western blot further confirmed that miR-129-3p affected the expression of Smad3. CONCLUSION: miR-129-3p inhibits the viability and migration ability of NIH3T3 cells during TGF-β-induced transformation into myofibroblasts by directly targeting Smad3.