The Epigenetically-Regulated microRNA-378a Targets TGF-β2 in TGF-β1-Treated Hepatic Stellate Cells

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Background/Aims: Recently, microRNAs (miRNAs) have been demonstrated to act as regulators of activation of hepatic stellate cells (HSCs). It is well known that the main profibrogenic inducer transforming growth factor-β1 (TGF-β1) contributes to HSC activation, which is a key event in liver fibrosis. Increasing studies show that miR-9-5p is down-regulated in liver fibrosis and restoration of miR-9-5p limits HSC activation. However, the role of miR-9-5p in TGF-β1-induced HSC activation is still not clear. Methods: miR-9-5p expression was quantified using real-time PCR in chronic hepatitis B (CHB) patients and TGF-β1-treated LX-2 cells. In CHB patients, histological activity index (HAI) and fibrosis stages were assessed using the Ishak scoring system. Effects of miR-9-5p on liver fibrosis in vivo and in vitro were analyzed. Luciferase activity assays were performed to examine the binding of miR-9-5p to the 3′-untranslated region of type I TGF-β receptor (TGFBR1) as well as TGFBR2. Results: Compared with healthy controls, miR-9-5p was reduced in CHB patients. There was a lower miR-9-5p expression in CHB patients with higher fibrosis scores or HAI scores. miR-9-5p was down-regulated by TGF-β1 in a dose-dependent manner. TGF-β1-induced HSC activation including cell proliferation, α-SMA and collagen expression was blocked down by miR-9-5p. Notably, miR-9-5p ameliorates carbon tetrachloride-induced liver fibrosis. As determined by luciferase activity assays, TGFBR1 and TGFBR2 were targets of miR-9-5p. Further studies demonstrated that miR-9-5p inhibited TGF-β1/Smads pathway via TGFBR1 and TGFBR2. Interestingly, promoter methylation was responsible for miR-9-5p down-regulation in liver fibrosis. The relationship between miR-9-5p expression and methylation was confirmed in CHB patients and TGF-β1-treated cells. Conclusion: Our results demonstrate that miR-9-5p could inhibit TGF-β1-induced HSC activation through TGFBR1 and TGFBR2. Loss of miR-9-5p is associated with its methylation status in liver fibrosis.

Section: Discussionsupporting

confidence: 47%

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

Chen

Fan

et al. 2017

Self Cite

“…The HSCs undergo a phenotypic transdifferentiation to contract myofibroblasts expressing α-SMA. During liver fibrogenesis, TGF-β1 causes an increase in HSC transit into myofibroblasts through the TGF-β1/Smad signaling pathway [23], which stimulates ECM synthesis, including synthesis of collagen type II, and suppresses its degeneration [24]. Accumulation of ECM forms scarring, leading to deterioration of hepatic function [25].…”

Section: Discussionmentioning

confidence: 99%

Biochemical and Molecular Mechanisms of Platelet-Rich Plasma in Ameliorating Liver Fibrosis Induced by Dimethylnitrosurea

Salem

Hamza

Alnahdi

et al. 2018

Background/Aims: Hepatic fibrosis is a wound-healing process in the chronically injured liver. Clinical application of platelet-rich plasma (PRP) is of considerable interest for wound healing and regeneration. In view of the regeneration effect of PRP, we designed this study to explore the hypothesis that PRP could play a role in improving the biochemical and molecular changes that occur in liver fibrosis induced by dimethylnitrosamine (DMN) in rats. Methods: Four groups were studied: control, PRP control, DMN (liver fibrosis), and DMN+PRP groups. Serum liver enzymes (alanine amino transferase ALT, aspartate amino transferase AST, gamma glutamyl transferase GGT, and lactate dehydrogenase LDH), and liver hydroxyproline content were measured colorimetrically.Interleukin-8 (IL-8) and B-cell lymphoma (Bcl2) were determined by enzyme-linked immunosorbent assay. And the expression levels of alpha-smooth muscle actin (α-SMA) ,transforming growth factor (TGF-β), and nuclear factor kappa B1(NF-қB1) were evaluated by quantitative real-time polymerase chain reaction. Results: Our results showed that PRP markedly improved the DMN-induced changes in liver enzymes accompanied by a significant decrease in liver hydroxyproline content and IL-8 level induced by DMN, and an increase in the anti-apoptotic marker Bcl-2. PRP also showed significant down-regulation of fibrosis-related genes α-SMA and TGF-β and a significant decrease in the inflammatory marker NF-қB1. Conclusion: Based on these encouraging results, we consider that PRP could be a promising new agent for liver regeneration and alleviation of fibrosis.

“…Hepatic stellate cells (HSCs), the primary effector cells in the liver, are involved in the development of pathological fibrosis [23, 24]. Thus, insight into mechanisms that regulate HSC activation is considered key for the treatment of hepatic fibrosis.…”

Section: Discussionmentioning

confidence: 99%

Trolline Ameliorates Liver Fibrosis by Inhibiting the NF-κB Pathway, Promoting HSC Apoptosis and Suppressing Autophagy

Bai¹,

Huang²,

Nie³

et al. 2017

Background/Aims: Previous studies have shown that trolline possesses various forms of pharmacological activity, including antibacterial and antiviral potency. The present paper addressed the putative hepatoprotective effects of trolline. Methods: Rats received 2 ml/kg CCl₄ (mixed 1: 1 in peanut oil) intragastrically twice a week for 8 weeks to induce hepatic fibrosis. The animals were then treated with trolline for additional 4 weeks. Liver pathology and collagen accumulation were observed by hematoxylin-eosin and Masson’s trichrome staining, respectively. Serum transaminase activity and collagen-related indicator level were determined by commercially available kits. NF-κB pathway activation was also examined. Moreover, the effects of trolline on hepatic stellate cell (HSC-T6) apoptosis, mitochondrial membrane potential (MMP), and autophagy were assessed. Results: Trolline significantly alleviated CCl₄-induced liver injury and notably reduced the accumulation of collagen in liver tissues. Trolline treatment also markedly decreased inflammatory cytokines levels by inhibiting the NF-κB pathway. Trolline strongly inhibited HSC-T6 activation and notably induced cell apoptosis by modulating the Bax/Bcl-2 ratio, caspase activity, and MMP. Moreover, trolline significantly inhibited HSC-T6 autophagy, as evidenced by the decrease in the formation of autophagic vacuoles and the number of autophagosomes, by regulating the expression levles of LC3, Beclin-1, P62, Atg 5 and 7. Conclusion: Our study demonstrates that trolline ameliorates liver fibrosis, possibly by inhibiting the NF-κB pathway, promoting HSCs apoptosis and suppressing autophagy.