AIM Keloid is a benign dermal tumor with excessive hyperplasia and deposition of collagen. As a common tumor suppressor gene, miR-133a-3p has not been studied in keloid. This study will delve into the specific mechanism of miR-133a-3p in keloid. METHODS Normal skin fibroblasts and keloid fibroblasts (KFs) were first isolated from patients' normal skin and keloid, and cells were identified by morphological observation and immunofluorescence. The expressions of miR-133a-3p and extracellular matrix (ECM)-associated markers (Collagen I, III and α smooth muscle activin) were detected by Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Cell viability and apoptosis of KFs were examined by Cell Counting Kit-8 assay, flow cytometry, and Caspase-3 colorimetry. TargetScan predicted target gene for miR-133a-3p was verified by luciferase assay, qRT-PCR and Western Blot (WB). WB was used to study protein expression of TGFBR1, phosphorylated -Smad2 (p-Smad2) and Smad2. Finally, a series of rescue experiments were performed to verify the intervention of target genes on miR-133a-3p. RESULTS MiR-133a-3p was lowly expressed in keloid tissue and KFs. Overexpression of miR-133a-3p inhibited the expression of ECM-associated markers, reduced KFs viability, and promoted apoptosis. It was verified that interference regulator 5 (IRF5) is miR-133a-3p target gene. The rescue experiments showed that IRF5 reversed the effect of miR-133a-3p mimic on inhibiting fibrosis, and reversed the effects on promoting apoptosis and reducing cell proliferation. CONCLUSION Overexpressed miR-133a-3p inhibits fibrosis by down-regulating IRF5 and thus inhibiting the TGF-β/Smad2 pathway. And it also promotes KFs apoptosis and reduces proliferation.

中文翻译：

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miR-133a-3p的过表达通过调节IRF5抑制TGF-β/ Smad2途径来抑制瘢痕loid成纤维细胞的纤维化和增殖。

AIM瘢痕loid是一种良性皮肤肿瘤，过度增生和胶原沉积。作为常见的抑癌基因，尚未在瘢痕loid中研究miR-133a-3p。这项研究将深入探讨瘢痕loid中miR-133a-3p的具体机制。方法首先从患者的正常皮肤和瘢痕loid中分离出正常皮肤的成纤维细胞和瘢痕loid成纤维细胞（KFs），并通过形态学观察和免疫荧光鉴定细胞。通过实时定量聚合酶链反应（qRT-PCR）检测miR-133a-3p和细胞外基质（ECM）相关标志物（胶原I，III和α平滑肌激活素）的表达。通过细胞计数试剂盒8检测，流式细胞仪和Caspase-3比色法检查KF的细胞活力和凋亡。通过萤光素酶测定法验证了TargetScan预测的miR-133a-3p靶基因，qRT-PCR和Western Blot（WB）。WB用于研究TGFBR1，磷酸化的-Smad2（p-Smad2）和Smad2的蛋白表达。最后，进行了一系列抢救实验，以验证靶基因对miR-133a-3p的干预。结果MiR-133a-3p在瘢痕loid组织和KFs中低表达。miR-133a-3p的过表达抑制了ECM相关标记的表达，降低了KFs的活力，并促进了细胞凋亡。证实干扰调节子5（IRF5）是miR-133a-3p的靶基因。救援实验表明，IRF5逆转了miR-133a-3p模拟物抑制纤维化的作用，并逆转了促进细胞凋亡和减少细胞增殖的作用。结论过量表达的miR-133a-3p通过下调IRF5抑制纤维化，从而抑制TGF-β/ Smad2通路。