Department of Breast and Thyroid Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, China.
Reichen Biomedical Co., Ltd., Kaohsiung, Taiwan 81155, ROC.
Biol Open. 2020 Dec 21;9(12):bio051904. doi: 10.1242/bio.051904.
Hypertrophic scar (HS) is a dermal fibro-proliferative disorder result from abnormal wound healing after skin injury. MicroRNA-9-5p (miR-9-5p) has been reported to be upregulated and closely related to collagen proteins in human dermal fibroblasts. However, the correlation and possible mechanism between miR-9-5p and HS require further investigation. The expressions of miR-9-5p in HS tissues and HS fibroblasts were detected by quantitative real-time PCR (RT-qPCR). The expression level of peroxisome proliferator-activated receptor β (PPARβ) was measured by RT-qPCR assay. The protein levels of PPARβ, α-SMA, Vimentin, COL1A, cyclin D1, bcl-2, and bax were detected by western blot assay. The effect of miR-9-5p and PPARβ on HS fibroblasts proliferation and apoptosis were detected by cell counting kit-8 (CCK-8) and flow cytometry assays. The interaction between miR-9-5p and PPARβ was predicted by TargetScan, and then confirmed by dual-luciferase reporter assay. MiR-9-5p expression was downregulated in HS tissues and HS fibroblasts. MiR-9-5p inhibited the levels of extracellular matrix-associated genes (α-SMA, Vimentin, COL1A) in HS fibroblasts. MiR-9-5p repressed proliferation and induced apoptosis of HS fibroblasts. PPARβ is a target gene of miR-9-5p. The silencing of PPARβ expression hindered proliferation and expedited apoptosis of HS fibroblasts. MiR-9-5p suppressed proliferation and promoted apoptosis of HS fibroblasts by targeting PPARβ. In this paper, we firstly disclosed that miR-9-5p hampered extracellular matrix deposition and proliferation, and induced apoptosis by targeting PPARβ in HS fibroblasts. Our findings provided a new role of miR-9-5p/PPARβ in the occurrence and development of HS fibroblasts, promising a new target for HS.
增生性瘢痕（HS）是一种皮肤纤维增生性疾病，是由于皮肤损伤后异常愈合导致的。已有研究报道，微小 RNA-9-5p（miR-9-5p）在人真皮成纤维细胞中上调，并与胶原蛋白密切相关。然而，miR-9-5p 与 HS 之间的相关性和可能的机制仍需进一步研究。通过实时定量 PCR（RT-qPCR）检测 HS 组织和 HS 成纤维细胞中 miR-9-5p 的表达。通过 RT-qPCR 检测过氧化物酶体增殖物激活受体β（PPARβ）的表达水平。通过 Western blot 检测 PPARβ、α-SMA、波形蛋白、COL1A、细胞周期蛋白 D1、bcl-2 和 bax 的蛋白水平。通过细胞计数试剂盒-8（CCK-8）和流式细胞术检测 miR-9-5p 和 PPARβ 对 HS 成纤维细胞增殖和凋亡的影响。通过 TargetScan 预测 miR-9-5p 和 PPARβ 之间的相互作用，然后通过双荧光素酶报告基因检测进行验证。MiR-9-5p 在 HS 组织和 HS 成纤维细胞中表达下调。MiR-9-5p 抑制 HS 成纤维细胞中细胞外基质相关基因（α-SMA、波形蛋白、COL1A）的水平。MiR-9-5p 抑制 HS 成纤维细胞增殖并诱导其凋亡。PPARβ 是 miR-9-5p 的靶基因。沉默 PPARβ 表达抑制 HS 成纤维细胞增殖并加速其凋亡。MiR-9-5p 通过靶向 PPARβ 抑制 HS 成纤维细胞增殖并促进其凋亡。在本文中，我们首次揭示了 miR-9-5p 通过靶向 PPARβ 抑制 HS 成纤维细胞中细胞外基质沉积、增殖并诱导其凋亡。我们的研究结果为 miR-9-5p/PPARβ 在 HS 成纤维细胞发生和发展中的作用提供了新的认识，为 HS 的治疗提供了新的靶点。
