Protective role for miR-9-5p in the fibrogenic transformation of human dermal fibroblasts

Abstract

BackgroundExcessive accumulation of extracellular matrix (ECM) proteins is the hallmark of fibrotic diseases, including skin fibrosis. This response relies on the activation of dermal fibroblasts that evolve into a pro-fibrogenic phenotype. One of the major players in this process is the cytokine transforming growth factor-β (TGF-β). MicroRNAs (miRNAs) are small non-coding RNAs that post-transcriptionally regulate gene expression affecting a wide range of pathophysiological events including fibrogenesis. MicroRNA-9-5p (miR-9-5p) has been shown to exert a protective role in lung and peritoneal fibrosis. This study aimed to evaluate the role of miR-9-5p in skin fibrosis.ResultsmiR-9-5p is up-regulated in TGF-β1-treated human dermal fibroblasts (HDFs). In silico identification of miR-9-5p targets spotted the type II TGF-β receptor (TGFBR2) as a potential TGF-β signaling-related effector for this miRNA. Consistently, over-expression of miR-9-5p in HDFs down-regulated TGFBR2 at both the mRNA and protein levels and reduced the phosphorylation of Smad2 and the translocation of Smad2/3 to the nucleus. In keeping, over-expression of miR-9-5p significantly delayed TGF-β1-dependent transformation of dermal fibroblasts, decreasing the expression of ECM protein collagen, type I, alpha 1 (Col1α1), and fibronectin (FN), the amount of secreted collagen proteins, and the expression of the archetypal myofibroblast marker alpha-smooth muscle actin (α-SMA). By contrast, specific inhibition of miR-9-5p resulted in enhanced presence of fibrosis markers. The expression of miR-9-5p was also detected in the skin and plasma in the mouse model of bleomycin-induced dermal fibrosis. Using lentiviral constructs, we demonstrated that miR-9-5p over-expression was also capable of deterring fibrogenesis in this same model.ConclusionsmiR-9-5p significantly prevents fibrogenesis in skin fibrosis. This is mediated by an abrogation of TGF-β-mediated signaling through the down-regulation of TGFBR2 expression in HDFs. These results may pave the way for future diagnostic or therapeutic developments for skin fibrosis based on miR-9-5p.Electronic supplementary materialThe online version of this article (doi:10.1186/s13069-016-0044-2) contains supplementary material, which is available to authorized users.

MiR‐9‐5p protects from kidney fibrosis by metabolic reprogramming

“…On the contrary, this effect was not observed in the PGC-1α −/− mice. 33 In previous work, 34,35 we identified miR-9-5p as a miRNA with anti-fibrotic potential in the lung, peritoneum, and skin. In these experiments the expression of miR-9-5p was not different between wild type and knockout (KO) mice in both the healthy (contralateral) or obstructed kidneys (UUO) (data not shown).…”

“…Its expression is increased in both patient samples and animal models of CKD and acute kidney injury (AKI). 34,35 We hypothesized that miR-9-5p could also be beneficial in renal fibrosis. 23,32 Nevertheless, there are few reports identifying miRNAs with a protective action as ongoing therapeutic efforts are based on attempts to antagonize a specific miRNA, which given its multiplicity of targets may result in unwanted side effects.…”

Long noncoding RNA AK089579 inhibits epithelial‐to‐mesenchymal transition of peritoneal mesothelial cells by competitively binding to microRNA‐296‐3p via DOK2 in peritoneal fibrosis

“…During the current study, the targeting relationship between microRNA‐296‐3p (miR‐296‐3p) and downstream of tyrosine kinase (DOK) 2 was determined through the application of an initial bioinformatics prediction followed by a confirmatory dual luciferase reporter assay. As an important subgroup of short noncoding RNAs, microRNAs (miRs) play essential roles in a large array of physiologic and pathologic conditions in which their aberrant expression has been correlated with disease pathogenesis and progression, including fibrogenesis (14, 15). As previously reported by Wang et al .…”

“…During the current study, the targeting relationship between microRNA-296-3p (miR-296-3p) and downstream of tyrosine kinase (DOK) 2 was determined through the application of an initial bioinformatics prediction followed by a confirmatory dual luciferase reporter assay. As an important subgroup of short noncoding RNAs, micro-RNAs (miRs) play essential roles in a large array of physiologic and pathologic conditions in which their aberrant expression has been correlated with disease pathogenesis and progression, including fibrogenesis (14,15). As previously reported by Wang et al (16), the low expression of miR-296 has been earmarked as a responsible element associated with unfavorable survival rates and poor prognoses among patients with hepatocellular carcinoma, whereas up-regulated expression levels of miR-296 exhibit tumor suppressor capabilities.…”

Epigenetically-Regulated MicroRNA-9-5p Suppresses the Activation of Hepatic Stellate Cells via TGFBR1 and TGFBR2

“…For instance, miR-9-5p regulates cardiac fibrosis by targeting PDGFR-β in rats [26]. A recent study has demonstrated that miR-9-5p has a protective role in the fibrogenic transformation of human dermal fibroblasts [27]. In liver fibrosis, a recent study shows that miR-9-5p not only inhibits HSC proliferation and activation in vitro but also inhibited CCl 4 -induced liver fibrosis in mice [11].…”