Role of microRNAs in Hepatic Stellate Cells and Hepatic Fibrosis: an Update

2020 ◽  
Vol 26 ◽  
Author(s):  
Sai Zhu ◽  
Xin Chen ◽  
Yu Chen ◽  
Xiao-Feng Li ◽  
Si-Yu Chen ◽  
...  

: MicroRNAs (miRNAs) are small non-coding RNA molecules that regulate the expression of targets genes by binding to the 3′-untranslated regions. They play vital roles in diverse biological processes, including the development of hepatic fibrosis (HF). HF is characterized by the accumulation of extracellular matrix (ECM) and hepatic stellate cells (HSCs) are considered a major cell type for producing ECM. Alteration of the HSC phenotype plays a crucial role in the HF pathological process. miRNAs involved in various biological process, such as differentiation, apoptosis, migration, and their relevant signaling pathways, are expressed in HSCs; however, emerging evidence indicates that numerous miRNAs are abnormally expressed in activated HSCs. In this review, we summarize the categorization of miRNAs in HF and describe the relationships among them. We also discuss miRNAs recently discovered to be related to HF, and attempt to find potential miRNAs that may serve as novel biomarkers for use in HF treatment.

2016 ◽  
Vol 310 (11) ◽  
pp. G1155-G1168 ◽  
Author(s):  
Maribel Arteaga ◽  
Na Shang ◽  
Xianzhong Ding ◽  
Sherri Yong ◽  
Scott J. Cotler ◽  
...  

Liver fibrosis can progress to cirrhosis and result in serious complications of liver disease. The pathogenesis of liver fibrosis involves the activation of hepatic stellate cells (HSCs), the underlying mechanisms of which are not fully known. Emerging evidence suggests that the classic histone deacetylases play a role in liver fibrosis, but the role of another subfamily of histone deacetylases, the sirtuins, in the development of hepatic fibrosis remains unknown. In this study, we found that blocking the activity of sirtuin 2 (SIRT2) by using inhibitors or shRNAs significantly suppressed fibrogenic gene expression in HSCs. We further demonstrated that inhibition of SIRT2 results in the degradation of c-MYC, which is important for HSC activation. In addition, we discovered that inhibition of SIRT2 suppresses the phosphorylation of ERK, which is critical for the stabilization of c-MYC. Moreover, we found that Sirt2 deficiency attenuates the hepatic fibrosis induced by carbon tetrachloride (CCl4) and thioacetamide (TAA). Furthermore, we showed that SIRT2, p-ERK, and c-MYC proteins are all overexpressed in human hepatic fibrotic tissues. These data suggest a critical role for the SIRT2/ERK/c-MYC axis in promoting hepatic fibrogenesis. Inhibition of the SIRT2/ERK/c-MYC axis represents a novel strategy to prevent and to potentially treat liver fibrosis and cirrhosis.


2020 ◽  
Vol 98 (1) ◽  
pp. 12-22 ◽  
Author(s):  
Dimple Prasher ◽  
Steven C. Greenway ◽  
Raja B. Singh

Mortality and morbidity from cardiovascular diseases (CVDs) represents a huge burden to society. It is recognized that environmental factors and individual lifestyles play important roles in disease susceptibility, but the link between these external risk factors and our genetics has been unclear. However, the discovery of sequence-independent heritable DNA changes (epigenetics) have helped us to explain the link between genes and the environment. Multiple diverse epigenetic processes, including DNA methylation, histone modification, and the expression of non-coding RNA molecules affect the expression of genes that produce important changes in cellular differentiation and function, influencing the health and adaptability of the organism. CVDs such as congenital heart disease, cardiomyopathy, heart failure, cardiac fibrosis, hypertension, and atherosclerosis are now being viewed as much more complex and dynamic disorders. The role of epigenetics in these and other CVDs is currently under intense scrutiny, and we can expect important insights to emerge, including novel biomarkers and new approaches to enable precision medicine. This review summarizes the recent advances in our understanding of the role of epigenetics in CVD.


2021 ◽  
Vol 12 ◽  
Author(s):  
Takefumi Kimura ◽  
Simran Singh ◽  
Naoki Tanaka ◽  
Takeji Umemura

The prevalence of non-alcoholic fatty liver disease (NAFLD) is globally increasing. Gaining control over disease-related events in non-alcoholic steatohepatitis (NASH), an advanced form of NAFLD, is currently an unmet medical need. Hepatic fibrosis is a critical prognostic factor in NAFLD/NASH. Therefore, a better understanding of the pathophysiology of hepatic fibrosis and the development of related therapies are of great importance. G protein-coupled receptors (GPCRs) are cell surface receptors that mediate the function of a great variety of extracellular ligands. GPCRs represent major drug targets, as indicated by the fact that about 40% of all drugs currently used in clinical practice mediate their therapeutic effects by acting on GPCRs. Like many other organs, various GPCRs play a role in regulating liver function. It is predicted that more than 50 GPCRs are expressed in the liver. However, our knowledge of how GPCRs regulate liver metabolism and fibrosis in the different cell types of the liver is very limited. In particular, a better understanding of the role of GPCRs in hepatic stellate cells (HSCs), the primary cells that regulate liver fibrosis, may lead to the development of drugs that can improve hepatic fibrosis in NAFLD/NASH. In this review, we describe the functions of multiple GPCRs expressed in HSCs, their roles in liver fibrogenesis, and finally speculate on the development of novel treatments for NAFLD/NASH.


2003 ◽  
Vol 285 (5) ◽  
pp. G880-G886 ◽  
Author(s):  
Hitoshi Ikeda ◽  
Kayo Nagashima ◽  
Mikio Yanase ◽  
Tomoaki Tomiya ◽  
Masahiro Arai ◽  
...  

Hepatic stellate cells (HSCs) play a central role in the development of hepatic fibrosis. Recent evidence has revealed that HSCs also play a role in its resolution, where HSC apoptosis was determined. Moreover, induction of HSC apoptosis caused a reduction of experimental hepatic fibrosis in rats. Thus knowing the mechanism of HSC apoptosis might be important to clarify the pathophysiology and establish the therapeutic strategy for hepatic fibrosis. In HSCs, Rho and Rho kinase are known to regulate contraction, migration, and proliferation with modulation of cell morphology. Controversy exists as to the participation of Rho and Rho kinase on cell survival, and little is known regarding this matter in HSCs. In this study, we directed our focus on the role of the Rho pathway in the regulation of HSC survival. C3, an inhibitor of Rho, increased histone-associated DNA fragmentation and caspase 3 activity with enhanced condensation of nuclear chromatin in rat cultured HSCs. Moreover, Y-27632, an inhibitor of Rho kinase, had the same effects, suggesting that inhibition of the Rho/Rho kinase pathway causes HSC apoptosis. On the other hand, lysophosphatidic acid, which stimulates the Rho/Rho kinase pathway, decreased histone-associated DNA fragmentation in HSCs. Inhibition of the Rho/Rho kinase pathway did not affect p53, Bcl-2, or Bax levels in HSCs. Thus we concluded that the Rho/Rho kinase pathway may play a role in the regulation of HSC survival.


PPAR Research ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Qinghui Zhang ◽  
Shihao Xiang ◽  
Qingqian Liu ◽  
Tao Gu ◽  
Yongliang Yao ◽  
...  

Background and Aims. Accumulating evidence reveals that PPARγ plays a unique role in the regulation of hepatic fibrosis and hepatic stellate cells (HSCs) activation. This study was aimed at investigating the role of PPARγ in hypoxia-induced hepatic fibrogenesis and its possible mechanism. Methods. Rats used for CCl4-induced hepatic fibrosis model were exposed to hypoxia for 8 hours each day. Rats exposed to hypoxia were treated with or without the PPARγ agonist rosiglitazone. Liver sections were stained with HE and Sirius red staining 8 weeks later. HSCs were exposed to hypoxic environment in the presence or absence of rosiglitazone, and expression of PPARγ and two fibrosis markers, α-SMA and desmin, were measured using western blot and immunofluorescence staining. Next, levels of PPARγ, α-SMA, and desmin as well as PKG and cGMP activity were detected using PI3K/AKT and a cGMP activator or inhibitor. Results. Hypoxia promoted the induction and progress of hepatic fibrosis and HSCs activation. Meanwhile, rosiglitazone significantly antagonized the effects induced by hypoxia. Signaling by sGC/cGMP/PKG promoted the inhibitory effect of PPARγ on hypoxia-induced activation of HSCs. Moreover, PI3K/AKT signaling or PDE5 blocked the above response of PPARγ. Conclusion. sGC/cGMP/PKG and PI3K/AKT signals act on PPARγ synergistically to attenuate hypoxia-induced HSC activation.


2010 ◽  
Vol 60 (4) ◽  
pp. 391-400 ◽  
Author(s):  
Sanja Aleksic-Kovacevic ◽  
V. Kukolj ◽  
B. Kureljusic ◽  
D. Marinkovic ◽  
Dj. Knezevic ◽  
...  

Genes ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 902
Author(s):  
Eva Costanzi ◽  
Carolina Simioni ◽  
Gabriele Varano ◽  
Cinzia Brenna ◽  
Ilaria Conti ◽  
...  

Extracellular vesicles (EVs) have attracted interest as mediators of intercellular communication following the discovery that EVs contain RNA molecules, including non-coding RNA (ncRNA). Growing evidence for the enrichment of peculiar RNA species in specific EV subtypes has been demonstrated. ncRNAs, transferred from donor cells to recipient cells, confer to EVs the feature to regulate the expression of genes involved in differentiation, proliferation, apoptosis, and other biological processes. These multiple actions require accuracy in the isolation of RNA content from EVs and the methodologies used play a relevant role. In liver, EVs play a crucial role in regulating cell–cell communications and several pathophysiological events in the heterogeneous liver class of cells via horizontal transfer of their cargo. This review aims to discuss the rising role of EVs and their ncRNAs content in regulating specific aspects of hepatocellular carcinoma development, including tumorigenesis, angiogenesis, and tumor metastasis. We analyze the progress in EV-ncRNAs’ potential clinical applications as important diagnostic and prognostic biomarkers for liver conditions.


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