Department of Plastic & Cosmetic Surgery, Women's Hospital of Nanjing Medical University (Nanjing Maternity and Child Health Care Hospital), 123rd Tianfei Street, Mochou Road, Nanjing 210004, China.
Milken School of Public Health, George Washington University, Washington DC, 20052, United States.
Curr Pharm Biotechnol. 2019;20(13):1147-1154. doi: 10.2174/1389201020666190725112304.
MicroRNA (miR)-340-5p has been identified to play a key role in several cancers. However, the function of miR-340-5p in skin fibroblasts remains largely unknown.
Gain of function experiments were performed by infecting normal skin fibroblast cells with a lentivirus carrying 22-bp miR-340-5p. Cell proliferation was detected by Cell Counting Kit-8 (CCK-8) assay. To uncover the mechanisms, mRNA-seq was used. Differentially expressed mRNAs were further determined by Gene Ontology and KEGG pathway analyses. The protein levels were analysed by Western blotting. A dual-luciferase reporter assay was used to detect the direct binding of miR-340-5p with the 3'UTR of Kruppel-like factor 2 (KLF2).
MiR-340-5p lentivirus infection suppressed normal skin fibroblast proliferation. The mRNAseq data revealed that 41 mRNAs were differentially expressed, including 22 upregulated and 19 downregulated transcripts in the miR-340-5p overexpression group compared with those in the control group. Gene Ontology and KEGG pathway analyses revealed that miR-340-5p overexpression correlated with the macromolecule biosynthetic process, cellular macromolecule biosynthetic process, membrane, and MAPK signalling pathway. Bioinformatics analysis and luciferase reporter assays showed that miR-340-5p binds to the 3'UTR of KLF2. Forced expression of miR-340-5p decreased the expression of KLF2 in normal skin fibroblasts. Overexpression of KLF2 restored skin fibroblast proliferation in the miR-340-5p overexpression group.
This study demonstrates that miR-340-5p may suppress skin fibroblast proliferation, possibly through targeting KLF2. These findings could help us understand the function of miR-340-5p in skin fibroblasts. miR-340-5p could be a therapeutic target for preventing scarring.
MicroRNA (miR)-340-5p 在多种癌症中发挥关键作用已得到证实。然而，miR-340-5p 在皮肤成纤维细胞中的功能仍知之甚少。
通过感染携带 22 个碱基 miR-340-5p 的慢病毒，对正常皮肤成纤维细胞进行功能获得实验。通过细胞计数试剂盒（CCK-8）检测细胞增殖。为了揭示机制，使用了 mRNA-seq。通过基因本体论和 KEGG 通路分析进一步确定差异表达的 mRNA。通过 Western blot 分析蛋白水平。双荧光素酶报告实验用于检测 miR-340-5p 与 Kruppel 样因子 2（KLF2）3'UTR 的直接结合。
miR-340-5p 慢病毒感染抑制正常皮肤成纤维细胞增殖。mRNAseq 数据显示，与对照组相比，miR-340-5p 过表达组中有 41 个 mRNA 差异表达，其中 22 个上调，19 个下调。基因本体论和 KEGG 通路分析显示，miR-340-5p 过表达与大分子生物合成过程、细胞大分子生物合成过程、膜和 MAPK 信号通路相关。生物信息学分析和荧光素酶报告实验表明，miR-340-5p 与 KLF2 的 3'UTR 结合。在正常皮肤成纤维细胞中强制表达 miR-340-5p 会降低 KLF2 的表达。在 miR-340-5p 过表达组中过表达 KLF2 可恢复皮肤成纤维细胞的增殖。
本研究表明，miR-340-5p 可能通过靶向 KLF2 抑制皮肤成纤维细胞增殖。这些发现有助于我们了解 miR-340-5p 在皮肤成纤维细胞中的功能。miR-340-5p 可能成为预防瘢痕形成的治疗靶点。
