Depletion of Thymosin �4 Promotes the Proliferation, Migration, and Activation of Human Hepatic Stellate Cells

Background/Aims: The activation of hepatic stellate cells (HSCs) is considered as a pivotal event in liver fibrosis and epithelial-mesenchymal transition (EMT) process has been reported to be involved in HSC activation. It is known that microRNAs (miRNAs) play a pro-fibrotic or anti-fibrotic role in HSC activation. Recently, emerging studies show that miR-30a is down-regulated in human cancers and over-expression of miR-30a inhibits tumor growth and invasion via suppressing EMT process. However, whether miR-30a could regulate EMT process in HSC activation is still unclear. Methods: miR-30a expression was quantified using real-time PCR in carbon tetrachloride (CCl₄)-induced rat liver fibrosis, activated HSCs and patients with cirrhosis. Roles of miR-30a in liver fibrosis in vivo and in vitro were also analyzed. Luciferase activity assays were performed to examine the binding of miR-30a to the 3′-untranslated region of snail family transcriptional repressor 1 (Snai1). Results: miR-30a was down-regulated in human cirrhotic tissues. In CCl₄ rats, reduced miR-30a was found in fibrotic liver tissues as well as isolated HSCs. There was a significant reduction in miR-30a in primary HSCs during culture days. miR-30a over-expression resulted in the suppression of CCl₄-induced liver fibrosis. Restoration of miR-30a led to the inhibition of HSC activation including cell proliferation, α-SMA and collagen expression. Notably, miR-30a inhibited EMT process, with a reduction in TGF-β1 and Vimentin as well as an increase in GFAP and E-cadherin. miR-30a induced a significant reduction in Snai1 protein expression when compared with the control. Interestingly, Snail protein expression was increased during liver fibrosis, indicating that there may be a negative correlation between miR-30a level and Snai1 protein expression. Further studies demonstrated that Snai1 was a target of miR-30a. Conclusion: Our results suggest that miR-30a inhibits EMT process, at least in part, via reduction of Snai1, leading to the suppression of HSC activation in liver fibrosis.

Section: Introductionmentioning

confidence: 99%

MicroRNA-30a Suppresses the Activation of Hepatic Stellate Cells by Inhibiting Epithelial-to-Mesenchymal Transition

Zheng¹,

Wang²,

Yu³

et al. 2018

“…In response to chronic liver injury, hepatic stellate cells (HSCs) are activated and differentiate into myofibroblast-like cells, and express abundant alpha smooth muscle actin (α-SMA) and extracellular matrix components [1,2]. Therefore, the activation and proliferation of HSCs are central events in the progression of liver fibrosis.…”

Section: Introductionmentioning

confidence: 99%

MicroRNA-125a-5p Contributes to Hepatic Stellate Cell Activation through Targeting FIH1

et al. 2016

Key Words MicroRNA • MiR-125a-5p • Hepatic stellate cells • Liver fibrosis • FIH1Abstract Background/Aims: Emerging evidence shows that microRNAs (miRNAs) play a crucial role in the regulation of activation, proliferation and apoptosis of hepatic stellate cells (HSCs). Previous studies have indicated that miR-125a-5p is correlated with hepatitis B virus replication and disease progression. However, little is known about the biological role and underlying mechanism of miR-125a-5p in liver fibrosis. Methods: We analyzed the level of miR-125a-5p in carbon tetrachloride-induced liver fibrosis and activated HSCs. We analyzed the effects of miR-125a-5p down-regulation on HSC activation and proliferation. We also analyzed the binding of miR-125a-5p to the 3′-untranslated region of factor inhibiting hypoxia-inducible factor 1 (FIH1) mRNA. Results: Up-regulation of miR-125a-5p was observed in the liver tissues of fibrotic mice and activated HSCs. Down-regulation of miR-125a-5p prevented the activation and proliferation of HSCs. FIH1, a negative modulator of hypoxia inducible factor 1, was confirmed to be a target of miR-125a-5p using the luciferase reporter assay. Further studies demonstrated that miR-125a-5p prompted the activation and proliferation of HSCs, at least in part, by down-regulating FIH1. Conclusion: Our findings shed new light on miRNAs as a promising therapeutic target in liver fibrosis.G. Li and J. Li contributed equally to this work.

“…Tβ4 is the major G-actin-sequestering molecule with diverse functions related to cell proliferation, migration, angiogenesis, cell survival, and inhibition of inflammation [4][5][6][7]. Multiple studies have indicated that Tβ4 protein may promote tissue regeneration in multiple processes including corneal, epidermal, and cardiac wound healing, and is also effective in inflammatory diseases including severe acute pancreatitis and bleomycininduced lung fibrosis [8].…”

Section: Introductionmentioning

confidence: 99%

Function of Thymosin Beta-4 in Ethanol-Induced Microglial Activation

Zhang¹,

Wu²,

Zeng³

et al. 2016

Background/Aims: Neuroinflammation mediated by activated microglia may play a pivotal role in a variety of central nervous system (CNS) pathologic conditions, including ethanolinduced neurotoxicity. The purpose of this study was to investigate the function of Tβ4 in ethanol-induced microglia activation. Methods: Quantitative real-time PCR was conducted to assess the expression of Tβ4 and miR-339-5p. Western blot analysis was used to measure the expression of Tβ4, phosphorylated p38, ERK, JNK, Akt, and NF-κB p65. The concentration of TNF-α and IL-1β was determined using ELISA. NO concentration was measured using a nitric oxide colorimetric BioAssay Kit. Double immunofluorescence was performed to determine Tβ4 expression, in order to assess microglial activation in neonatal mouse FASD model. Results: Increased Tβ4 expression was observed in ethanol treated microglia. Knockdown of Tβ4 enhanced ethanol-induced inflammatory mediators tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) and nitric oxide (NO) in BV-2 cells was performed. Exogenous Tβ4 treatment significantly inhibited expression and secretion of these inflammatory mediators. Tβ4 treatment attenuated p38, ERK MAPKs, and nuclear factor-kappa B (NF-κB) pathway activation, and enhanced miR-339-5p expression induced by ethanol exposure in microglia. A neonatal mouse fetal alcohol spectrum disorders (FASD) model showed that Tβ4 expression in the microglia of the hippocampus was markedly enhanced, while Tβ4 treatment effectively blocked the ethanol-induced increase in inflammatory mediators, to the level expressed in vehicle-treated control animals. Conclusion: This study is the first to demonstrate the function of Tβ4 in ethanol-induced microglia activation, thus contributing to a more robust understanding of the role of Tβ4 treatment in CNS disease.