Department of Plastic and Aesthetic Surgery, Yantai Yuhuangding Hospital, Yantai, Shandong, China (mainland).
Med Sci Monit. 2020 Apr 20;26:e920736. doi: 10.12659/MSM.920736.
BACKGROUND Hypertrophic scar results from an abnormal repair response to trauma in the skin and involves fibroblasts proliferation with increased collagen deposition. Transforming growth factor-ß1 (TGF-ß1) and TGF-ß receptor type I (TGF-ßR1) are involved in tissue repair and are increased by ubiquitin-specific protease 4 (USP4). This study aimed to investigate the effects of TGF-ßR1 and USP4 in human tissue samples of hypertrophic scar and on cell proliferation and cell migration in primary fibroblast cultures in vitro. MATERIAL AND METHODS Skin excision tissue samples with adjacent normal skin were obtained from 15 patients with hypertrophic scar, which provided tissue sections and primary fibroblast culture for analysis. Immunohistochemistry detected the expression of USP4 and TGF-ßR1 in tissue sections. MicroRNA (miRNAs) expression levels were measured by quantitative real-time polymerase chain reaction (qRT-PCR). Western blot was performed to measure protein expression levels. Cultured skin fibroblasts were investigated using immunofluorescence staining. Fibroblast proliferation, apoptosis, and migration were measured with the Cell Counting Kit-8 (CCK-8) assay, flow cytometry, and a wound-healing assay, respectively. RESULTS The expression of USP4 and TGF-ßR1 in hypertrophic scar were increased compared with normal skin. Fibroblasts cultured from hypertrophic scar tissue showed increased expression of of USP4 and TGF-ßR1. Fibroblast transfection with USP4 short-interfering RNA (siRNA) resulted in reduced fibroblast proliferation and migration, and increased apoptosis. Downregulation of USP4 inhibited the expression of TGF-ßR1 protein and increased the expression levels of Smad7 protein. CONCLUSIONS USP4 regulated the proliferation, migration, and apoptosis of hypertrophic scar fibroblasts by regulating the TGF-ß1 signaling pathway.
增生性瘢痕是由于皮肤创伤后的异常修复反应引起的，涉及成纤维细胞增殖和胶原沉积增加。转化生长因子-β1（TGF-β1）和 TGF-β 受体 I 型（TGF-βR1）参与组织修复，并被泛素特异性蛋白酶 4（USP4）上调。本研究旨在探讨 TGF-βR1 和 USP4 在人增生性瘢痕组织样本中的作用，以及在体外原代成纤维细胞培养中的细胞增殖和细胞迁移作用。
从 15 名增生性瘢痕患者中获取皮肤切除组织样本及相邻正常皮肤，提供组织切片和原代成纤维细胞培养进行分析。免疫组织化学检测组织切片中 USP4 和 TGF-βR1 的表达。采用实时定量聚合酶链反应（qRT-PCR）测量 microRNA（miRNAs）表达水平。采用 Western blot 检测蛋白表达水平。通过免疫荧光染色研究培养的皮肤成纤维细胞。采用细胞计数试剂盒-8（CCK-8）测定、流式细胞术和划痕愈合试验分别测量成纤维细胞增殖、凋亡和迁移。
与正常皮肤相比，增生性瘢痕中 USP4 和 TGF-βR1 的表达增加。从增生性瘢痕组织培养的成纤维细胞中，USP4 和 TGF-βR1 的表达增加。成纤维细胞用 USP4 短发夹 RNA（siRNA）转染后，细胞增殖和迁移减少，凋亡增加。USP4 下调抑制 TGF-βR1 蛋白表达，增加 Smad7 蛋白表达水平。
USP4 通过调节 TGF-β1 信号通路调节增生性瘢痕成纤维细胞的增殖、迁移和凋亡。
