Ling Chen, Qian Li, Xun Lu, Xiaohua Dong* and Jingyun Li* Pages 1147 - 1154 ( 8 )
Objective: 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.
Methods: 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).
Results: 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.
Conclusion: 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.
miR-340-5p, skin fibroblasts, cell growth, KLF2, microRNAs, fibroblast proliferation.
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, 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, Milken School of Public Health, George Washington University, Washington DC, 20052, Department of Pediatric, Jingjiang People's Hospital Affiliated to Yangzhou University, Jingjiang 214500, Jiangsu, Nanjing Maternal and Child Health Medical Institute, Women's Hospital of Nanjing Medical University (Nanjing Maternity and Child Health Care Hospital), Nanjing