miR-140-5p attenuates hepatic fibrosis by directly targeting TGFβR1

Abstract

Objective

To explore the protective effect and related mechanism of miR-140-5p on liver fibrosis by interfering with TGF-β/Smad signaling pathway.

Methods

Liver fibrosis mice models were established by intraperitoneal injection of CCL₄. Hematoxylin and eosin (HE) staining was used to detect the structural and morphological changes of the liver. Masson staining was used to detect collagen deposition. Human hepatic stellate cells (HSCs, LX-2) were transfected with miR-140-5p mimic or inhibitor then treated with TGF-β1. The qRT-PCR and Western blotting was used to detect the expression of related molecules. The luciferase reporter assay was used to identify the target of miR-140-5p.

Results

Our results indicated that miR-140-5p expression was downregulated in fibrotic liver tissues of model mice and LX-2 cells treated with TGF-β1. The overexpression of miR-140-5p decreased the expression of collagen1(COL1) and α-smooth muscle actin(α-SMA), inhibited the phosphorylation of Smad-2/3 (pSmad-2/3) in LX-2 cells. Conversely, the knockdown of miR-140-5p upregulated COL1 and α-SMA expression, increased Smad-2/3 phosphorylation. A dual-luciferase reporter assay showed that TGFβR1 was a target gene of miR-140-5p. The overexpression of miR-140-5p suppressed TGFβR1 expression in LX-2 cells. Additionally, knockdown of TGFβR1 decreased the expression of COL1 and α-SMA. Conversely, the overexpression of TGFβR1 reversed the inhibitory effect of miR-140-5p upregulation on expression of COL1 and α-SMA.

Conclusion

miR-140-5p bound to TGFβR1 mRNA 3′-untranslated region(3′UTR) and inhibited the expression of TGFβR1, pSmad-2/3, COL1 and α-SMA, thereby exerting a potential therapeutic effect on hepatic fibrosis.

Keywords:

• Extracellular matrix
• hepatic fibrosis
• hepatic stellate cells
• miR-140-5p
• TGF-β1/Smad signal pathway

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

All relevant data are within the paper.

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.