scholarly journals Heme Oxygenase-1 Inhibits the Proliferation of Hepatic Stellate Cells by Activating PPARγ and Suppressing NF-κB

2022 ◽  
Vol 2022 ◽  
pp. 1-10
Author(s):  
Hui Yang ◽  
Li Zhang ◽  
Jie Chen ◽  
Xiaoqian Zhang ◽  
Zhongfu Zhao ◽  
...  

Background. Hepatic stellate cells (HSCs) are reported to play significant roles in the development of liver fibrosis. Heme oxygenase-1 (HO-1) is a key rate-limiting enzyme, which could decrease collagen synthesis and liver damage. Nevertheless, it was yet elusive towards the function and mechanism of HO-1. Methods. An HO-1 inducer Hemin or an HO-1 inhibitor ZnPP-IX was used to treat the activated HSC-T6, respectively. MTT assay was adopted to detect cell proliferation. Immunocytochemical staining was employed to test the levels of alpha-smooth muscle actin (α-SMA), peroxisome proliferator-activated receptor-γ (PPARγ), and nuclear factor-kappa B (NF-kappa B) levels in HSC-T6. HO-1, PPARγ, and NF-κB expression levels were measured by qRT-PCR and Western blotting. ELISA was then used to detect the levels of transforming growth factor- (TGF-) beta 1 (TGF-β1), interleukin-6 (IL-6), serum hyaluronic acid (HA), and serum type III procollagen aminopeptide (PIIIP). Results. HSC-T6 proliferation was inhibited in Hemin-treated HSCs. The levels of α-SMA, HA, and PIIIP and the production of ECM were lower in Hemin-treated HSCs, whereas those could be rescued by ZnPP-IX. NF-κB activation was decreased, but PPARγ expression was increased after HO-1 upregulation. Furthermore, the levels of TGF-β1 and IL-6, which were downstream of activated NF-κB in HSC-T6, were reduced. The PPAR-specific inhibitor GW9662 could block those mentioned effects. Conclusions. Our data demonstrated that HO-1 induction could inhibit HSC proliferation and activation by regulating PPARγ expression and NF-κB activation directly or indirectly, which makes it a promising therapeutic target for liver fibrosis.

2021 ◽  
Author(s):  
Zuoning Han ◽  
Yanling Ma ◽  
Gary Cao ◽  
Zhengping Ma ◽  
Ruihua Chen ◽  
...  

Hepatic stellate cells (HSCs) are thought to play key roles in the development of liver fibrosis.  Extensive evidence has established the concept that αV integrins are involved in the activation of latent transforming growth factor β (TGF-β), a master regulator of the fibrotic signaling cascade.  Based on mRNA and protein expression profiling data, we found that αVβ1 integrin is the most abundant member of the αV integrin family in either quiescent or TGF-β1-activated primary human HSCs.  Unexpectedly, either a selective αVβ1 inhibitor, Compound 8 (C8), or a pan-αV integrin inhibitor, GSK3008348, decreased TGF-β1-activated procollagen I production in primary human HSCs, in which the role of β1 integrin was confirmed by ITGB1 siRNA. In contrast to an Activin receptor-like kinase 5 (Alk5) inhibitor, C8 and GSK3008348 failed to inhibit TGF-β1 induced SMAD3 and SMAD2 phosphorylation, but inhibited TGF-β-induced phosphorylation of ERK1/2 and STAT3, suggesting that αVβ1 integrin is involved in non-canonical TGF-β signaling pathways. Consistently, ITGB1 siRNA significantly decreased phosphorylation of ERK1/2. Furthermore, a selective inhibitor of MEK1/2 blocked TGF-β1 induced phosphorylation of ERK1/2 and decreased TGF-β1 induced procollagen I production, while a specific inhibitor of STAT3 had no effect on TGF-β1 induced procollagen I production.  Taken together, current data indicate that αVβ1 integrin can regulate TGF-β signaling independent of its reported role in activating latent TGF-β.  Our data further support that αVβ1 inhibition is a promising therapeutic target for the treatment of liver fibrosis.


Author(s):  
Qi Yan ◽  
Linxin Pan ◽  
Shunli Qi ◽  
Fang Liu ◽  
Zhen Wang ◽  
...  

The therapeutic approach of liver fibrosis is still an unsolved clinical problem worldwide. Notably, the accumulation of extracellular matrix (ECM) in the liver is mediated by the production of cytokines and growth factors, such as transforming growth factor-β1 (TGF-β1) in hepatic stellate cells (HSCs). Ring finger protein 2 (RNF2) was identified as the catalytic subunit of polycomb repressive complex 1 (PRC1), mediating the monoubiquitination of histone H2A. In recent years, a growing amount of evidence suggests that RNF2 may play an important role in multiple pathological processes involved in cancer. Here, we explored the role of RNF2 in liver fibrogenesis and its potential mechanisms. The results showed that RNF2 was up-regulated in human fibrotic liver tissue. Knockdown of RNF2 led to a decreasing expression of collagen1 and α-smooth muscle actin (α-SMA) in LX-2 cells, which was upregulated by RNF2 overexpression. Moreover, RNF2 overexpression significantly promoted TGF-β1-induced LX-2 cell proliferation but decreased apoptosis. Furthermore, knockdown of RNF2 inhibited the activation of ERK/p38 signaling pathways induced by TGF-β1. These data suggested that RNF2 is an effective pro-fibrogenic factor for HSC activation via ERK/p38 signaling pathway. RNF2 inhibition might be a promising therapeutic target for liver fibrosis.


2017 ◽  
Vol 43 (6) ◽  
pp. 2242-2252 ◽  
Author(s):  
Fujun Yu ◽  
BiCheng Chen ◽  
XuFei Fan ◽  
Guojun Li ◽  
Peihong Dong ◽  
...  

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.


2007 ◽  
Vol 293 (3) ◽  
pp. F885-F894 ◽  
Author(s):  
Amie Traylor ◽  
Thomas Hock ◽  
Nathalie Hill-Kapturczak

Excess transforming growth factor-β1 (TGF-β1) in the kidney leads to increased cell proliferation and deposition of extracellular matrix, resulting in progressive kidney fibrosis. TGF-β1, however, stabilizes and attenuates tissue injury through the activation of cytoprotective proteins, including heme oxygenase-1 (HO-1). HO-1 catabolizes pro-oxidant heme into substances with anti-oxidant, anti-apoptotic, anti-fibrogenic, vasodilatory and immune modulatory properties. Little is known regarding the molecular regulation of human HO-1 induction by TGF-β1 except that it is dependent on de novo RNA synthesis and requires a group of structurally related proteins called Smads. It is not known whether other DNA binding proteins are required to initiate transcription of HO-1 and, furthermore, the promoter region(s) involved in TGF-β1-mediated induction of HO-1 has not been identified. The purpose of this study was to further delineate the molecular regulation of HO-1 by TGF-β1 in human renal proximal tubular cells. Actinomycin D and nuclear run-on studies demonstrate that TGF-β1 augments HO-1 expression by increased gene transcription and does not involve increased mRNA stability. Using transient transfection, mithramycin A, small interfering RNA, electrophoretic mobility shift assays, and decoy oligonucleotide experiments, a TGF-β1-responsive region is identified between 9.1 and 9.4 kb of the human HO-1 promoter. This ∼280-bp TGF-β1-responsive region contains a putative Smad binding element and specificity protein 1 binding sites, both of which are required for human HO-1 induction by TGF-β1.


2021 ◽  
pp. 002215542110536
Author(s):  
Ikuyo Inoue ◽  
Xian-Yang Qin ◽  
Takahiro Masaki ◽  
Yoshihiro Mezaki ◽  
Tomokazu Matsuura ◽  
...  

Transforming growth factor-β (TGF-β) activation is involved in various pathogeneses, such as fibrosis and malignancy. We previously showed that TGF-β was activated by serine protease plasma kallikrein-dependent digestion of latency-associated peptides (LAPs) and developed a method to detect LAP degradation products (LAP-DPs) in the liver and blood using specific monoclonal antibodies. Clinical studies have revealed that blood LAP-DPs are formed in the early stages of liver fibrosis. This study aimed to identify the cell source of LAP-DP formation during liver fibrosis. The N-terminals of LAP-DPs ending at residue Arg58 (R58) were stained in liver sections of a bile duct-ligated liver fibrosis model at 3 and 13 days. R58 LAP-DPs were detected in quiescent hepatic stellate cells at day 3 and in macrophages on day 13 after ligation of the bile duct. We then performed a detailed analysis of the axial localization of R58 signals in a single macrophage, visualized the cell membrane with the anti-CLEC4F antibody, and found R58 LAP-DPs surrounded by the membrane in phagocytosed debris that appeared to be dead cells. These findings suggest that in the early stages of liver fibrosis, TGF-β is activated on the membrane of stellate cells, and then the cells are phagocytosed after cell death: (J Histochem Cytochem XX:XXX–XXX, XXXX)


2018 ◽  
Vol 27 (2) ◽  
pp. 115-121
Author(s):  
Mona A. Abu El Makarem ◽  
Ghada M. El-Sagheer ◽  
Moustafa A. Abu El-Ella

Objective: To investigate the possible role of signal transducer and activator of transcription 5 (STAT5) in the pathogenesis of liver fibrosis in Egyptian patients with chronic hepatitis C (CHC) virus infection and its relation to hepatic stellate cells (HSC). Subjects and Methods: Sixty-five patients (46 males and 19 females) were divided into 4 groups based on the severity of fibrosis as detected by Fibroscan as follows: F1, n = 15; F2, n = 21; F3, n = 13; and F4, n = 16. Twenty age- and gender-matched healthy persons volunteered as controls. The serum levels of STAT5, TGF-β1, α-smooth muscle actin (α-SMA), fasting blood sugar, and fasting insulin, as well as homeostasis model assessment of insulin resistance (HOMA-IR), were determined and compared for all groups. The usefulness of the studied serum biomarkers for predicting liver fibrosis was evaluated using a receiver operating characteristic curve. Results: Serum levels of STAT5 were significantly lower in patients compared to controls (9.69 ± 5.62 vs. 14.73 ± 6.52, p ≤ 0.001); on the contrary, TGF-β1, α-SMA, and HOMA-IR were significantly higher in patients compared to controls (mean: 1,796.04 vs. 1,636.94; 14.94 vs. 8.1; and 7.91 vs. 4.18; p ≤ 0.01 and 0.001, respectively). TGF-β1 and α-SMA showed a progressive increase with advancing severity of hepatic fibrosis (mean TGF-β1: 2,058.4 in F1-F2 and 1,583.8 in F3-F4, p ≤ 0.04; mean α-SMA: 13.59 in F1-F2 and 16.62 in F3-F4, p ≤ 0.05). STAT5 had a significant negative correlation with TGF-β1 (p ≤ 0.001), while no correlation was detected with α-SMA (p ≤ 0.8). Conclusions: STAT5 may play a significant role in hepatic fibrogenesis through the induction of TGF-β1 but not through the activation of hepatic stellate cells.


2012 ◽  
Vol 66 (3) ◽  
pp. 219-225 ◽  
Author(s):  
Jingjing Qian ◽  
Minghui Niu ◽  
Xuguang Zhai ◽  
Qian Zhou ◽  
Yajun Zhou

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Qi Wang ◽  
Song Wei ◽  
Lei Li ◽  
Qingfa Bu ◽  
Haoming Zhou ◽  
...  

AbstractLiver fibrosis is a patho-physiological process which can develop into cirrhosis, and hepatic carcinoma without intervention. Our study extensively investigated the mechanisms of lncRNA NEAT1 and miR-139-5p in regulating liver fibrosis progression. Our results demonstrated that the expression of lncRNA NEAT1 was increased and the expression of miR-139-5p was decreased in fibrotic liver tissues. LncRNA NEAT1 could sponge miR-139-5p and promoted hepatic stellate cells (HSCs) activation by directly inhibiting the expression of miR-139-5p. The co-localization of lncRNA NEAT1 with miR-139-5p was shown in the cytosols of activated HSCs. miR-139-5p upregulation could suppress the expression of β-catenin. The overexpression of β-catenin promoted HSCs activation. Moreover, we found that β-catenin could interact with SOX9 promoted HSCs activation. Our further studies demonstrated that SOX9 could bind with the TGF-β1 promoter and promoted the transcription activity of TGF-β1. The upregulation of TGF-β1 further promoted HSCs activation. In vivo study also suggested that lncRNA NEAT1 knockdown and miR-139-5p overexpression alleviated murine liver fibrosis. LncRNA NEAT1 exacerbated liver fibrosis by suppressing the expression of miR-139-5p. Collectively, our study suggested that miR-139-5p sponged by lncRNA NEAT1 regulated liver fibrosis via targeting β-catenin/SOX9/TGF-β1 Pathway.


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