scholarly journals PTPRO-Associated Hepatic Stellate Cell Activation Plays a Critical Role in Liver Fibrosis

2015 ◽  
Vol 35 (3) ◽  
pp. 885-898 ◽  
Author(s):  
Xudong Zhang ◽  
Zhongming Tan ◽  
Youjing Wang ◽  
Junwei Tang ◽  
Runjiu Jiang ◽  
...  

Background/Aims: PTPRO (protein tyrosine phosphatase, receptor type O) is implicated in diverse physiological and pathological processes in cancer and hepatic ischemia/reperfusion injury, although little is known about its role in hepatic fibrosis. Methods: Here, by using genetically deficient mice, we reported that PTPRO knockout (PTPRO-/-) significantly attenuated liver injury, release of inflammatory factors, tissue remodeling, and liver fibrosis in two experimental mouse models of fibrogenesis induced by bile-duct ligation or carbon tetrachloride administration. Results: However, we proved that PTPRO expression was strongly downregulated in clinical and experimental liver fibrosis specimens. Further investigations revealed that stimulation of primary hepatic stellate cells (HSCs) and hepatocytes with specific activator platelet-derived growth factor (PDGF)-BB increased PTPRO transcription in HSCs but had the opposite effect in primary hepatocytes. More importantly, synthetic short hairpin RNA targeting PTPRO significantly neutralized PDGF-BB-induced HSC proliferation and myofibroblast marker expression through downregulated phosphorylation of extracellular signal-regulated kinase (ERK) and AKT. Conclusion: These observations confirm that PTPRO plays a critical role in liver fibrogenesis by affecting PDGF signaling in HSC activation and might be developed into a feasible therapeutic approach for the treatment of chronic fibrotic liver diseases.

2021 ◽  
Vol 21 ◽  
Author(s):  
Fahim Rejanur Tasin ◽  
Debasish Halder ◽  
Chanchal Mandal

: Liver fibrosis is one of the leading causes for cirrhotic liver disease and the lack of therapies to treat fibrotic liver is a major concern. Liver fibrosis is mainly occurred by activation of hepatic stellate cells and some stem cell therapies had previously reported for treatment. However, due to some problems with cell-based treatment, a safe therapeutic agent is vehemently sought by the researchers. Extracellular vesicles are cell-derived nanoparticles that are employed in several therapeutic approaches, including fibrosis, for their ability to transfer specific molecules in the target cells. In this review the possibilities of extracellular vesicles to inactivate stellate cells are summarized and discussed. According to several studies, extracellular vesicles from different sources can either put beneficial or detrimental effects by regulating the activation of stellate cells. Therefore, targeting extracellular vesicles for maximizing or inhibiting their production is a potential approach for fibrotic liver treatment. Extracellular vesicles from different cells can also inactivate stellate cells by carrying out the paracrine effects of those cells, working as the agents. They are also implicated as smart carrier of anti-fibrotic molecules when their respective parent cells are engineered to produce specific stellate cell-regulating substances. A number of studies showed stellate cell activation can be regulated by up/downregulation of specific proteins, and extracellular vesicle-based therapies can be an effective move to exploit these mechanisms. In conclusion, EVs are advantageous nano-carriers with the potential to treat fibrotic liver by inactivating activated stellate cells by various mechanisms.


2020 ◽  
Vol 40 (03) ◽  
pp. 307-320
Author(s):  
Michitaka Matsuda ◽  
Ekihiro Seki

AbstractChronic liver injury due to viral hepatitis, alcohol abuse, and metabolic disorders is a worldwide health concern. Insufficient treatment of chronic liver injury leads to fibrosis, causing liver dysfunction and carcinogenesis. Most cases of hepatocellular carcinoma (HCC) develop in the fibrotic liver. Pathological features of liver fibrosis include extracellular matrix (ECM) accumulation, mesenchymal cell activation, immune deregulation, and angiogenesis, all of which contribute to the precancerous environment, supporting tumor development. Among liver cells, hepatic stellate cells (HSCs) and macrophages play critical roles in fibrosis and HCC. These two cell types interplay and remodel the ECM and immune microenvironment in the fibrotic liver. Once HCC develops, HCC-derived factors influence HSCs and macrophages to switch to protumorigenic cell populations, cancer-associated fibroblasts and tumor-associated macrophages, respectively. This review aims to summarize currently available data on the roles of HSCs and macrophages in liver fibrosis and HCC, with a focus on their interaction.


Hepatology ◽  
2006 ◽  
Vol 44 (3) ◽  
pp. 561-572 ◽  
Author(s):  
Laura Llacuna ◽  
Montserrat Marí ◽  
Carmen Garcia-Ruiz ◽  
José C. Fernandez-Checa ◽  
Albert Morales

2020 ◽  
Author(s):  
Yahong Liu ◽  
Ying Cheng ◽  
Wei Zhang ◽  
Hongqi Tian

Abstract Oxidative stress plays a critical role in cerebral ischemia-reperfusion injury. We previously developed a powerful antioxidant, HL-008, and this study aimed to investigate the neuroprotective function of HL-008. The in vitro and in vivo efficacy of HL-008 was evaluated using a PC-12 cell oxidative stress model induced by hydrogen peroxide and a rat model of middle cerebral artery occlusion, respectively. The MTT assay was used to analyze cell viability. TTC staining, HE staining, immunofluorescence, western blot, and proteomics were used to evaluate the infarction volume, brain tissue morphology, apoptosis, inflammation, and related pathways. Indicators related to oxidative levels were mainly detected using commercial kits. HL-008 significantly reduced the cerebral infarction area induced by ischemia-reperfusion, improved the neurological score, alleviated oxidative stress and inflammation in the brain tissue, reduced glial cell activation, inhibited brain tissue apoptosis by influencing multiple signaling pathways, and had a neuroprotective effect. If HL-008 is successfully developed, it can significantly improve the quality of life of stroke patients.


2020 ◽  
Vol 26 (3) ◽  
pp. 280-293 ◽  
Author(s):  
Le Thi Thanh Thuy ◽  
Hoang Hai ◽  
Norifumi Kawada

Cytoglobin (Cygb), a stellate cell-specific globin, has recently drawn attention due to its association with liver fibrosis. In the livers of both humans and rodents, Cygb is expressed only in stellate cells and can be utilized as a marker to distinguish stellate cells from hepatic fibroblast-derived myofibroblasts. Loss of Cygb accelerates liver fibrosis and cancer development in mouse models of chronic liver injury including diethylnitrosamine-induced hepatocellular carcinoma, bile duct ligation-induced cholestasis, thioacetamide-induced hepatic fibrosis, and choline-deficient L-amino acid-defined diet-induced non-alcoholic steatohepatitis. This review focuses on the history of research into the role of reactive oxygen species and nitrogen species in liver fibrosis and discusses the current perception of Cygb as a novel radical scavenger with an emphasis on its role in hepatic stellate cell activation and fibrosis.


2021 ◽  
Author(s):  
Ning Wang ◽  
Xiajing Li ◽  
Zhiyong Zhong ◽  
Yaqi Qiu ◽  
Shoupei Liu ◽  
...  

Abstract BackgroundExosomes secreted from stem cells exerted salutary effects on the fibrotic liver. Herein, the roles of exosomes derived from human embryonic stem cell (hESC) in anti-fibrosis were extensively investigated. Compared with two-dimensional (2D) culture, the clinical and biological relevance of three-dimensional (3D) cell spheroids were greater because of their higher regeneration potential since they behave more like cells in vivo. In our study, exosomes derived from 3D human embryonic stem cells (hESC) spheroids and the monolayer (2D) hESCs were collected and compared the therapeutic potential for fibrotic liver in vitro and in vivo. ResultsIn vitro, PKH26 labled-hESC-Exosomes were shown to be internalized and integrated into TGFβ-activated-LX2 cells, and reduced the expression of profibrogenic markers, thereby regulating cellular phenotypes. TPEF imaging indicated that PKH26-labled-3D-hESC-Exsomes possessed an enhanced capacity to accumulate in the livers and exhibited more dramatic therapeutic potential in the injured livers of fibrosis mouse model. 3D-hESC-Exosomes decreased profibrogenic markers and liver injury markers, and improved the level of liver functioning proteins, eventually restoring liver function of fibrosis mice. miRNA array revealed a significant enrichment of miR-6766-3p in 3D-hESC-Exosomes, moreover, bioinformatics and dual luciferase reporter assay identified and confirmed the TGFβRII gene as the target of miR-6766-3p. Furthermore, the delivery of miR-6766-3p into activated-LX2 cells decreased cell proliferation, chemotaxis and profibrotic effects, and further investigation demonstrated that the expression of target gene TGFβRII and its downstream SMADs proteins, especially phosphorylated protein p-SMAD2/3 was also notably down-regulated by miR-6766-3p. These findings unveiled that miR-6766-3p in 3D-hESC-Exosomes inactivated SMADs signaling by inhibiting TGFβRII expression, consequently attenuating stellate cell activation and suppressing liver fibrosis. ConclusionsOur results showed that miR-6766-3p in the 3D-hESC-Exosomes inactivates smads signaling by restraining TGFβRII expression, attenuated LX2 cell activation and suppressed liver fibrosis, suggesting that 3D-hESC-Exosome enriched-miR6766-3p is a novel anti-fibrotic therapeutics for treating chronic liver disease. These results also proposed a significant strategy that 3D-Exo could be used as natural nanoparticles to rescue liver injury via delivering antifibrotic miR-6766-3p.


2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Vaishaali Natarajan ◽  
Edward N. Harris ◽  
Srivatsan Kidambi

Liver fibrosis is a wound-healing response to chronic liver injury such as alcoholic/nonalcoholic fatty liver disease and viral hepatitis with no FDA-approved treatments. Liver fibrosis results in a continual accumulation of extracellular matrix (ECM) proteins and paves the way for replacement of parenchyma with nonfunctional scar tissue. The fibrotic condition results in drastic changes in the local mechanical, chemical, and biological microenvironment of the tissue. Liver parenchyma is supported by an efficient network of vasculature lined by liver sinusoidal endothelial cells (LSECs). These nonparenchymal cells are highly specialized resident endothelial cell type with characteristic morphological and functional features. Alterations in LSECs phenotype including lack of LSEC fenestration, capillarization, and formation of an organized basement membrane have been shown to precede fibrosis and promote hepatic stellate cell activation. Here, we review the interplay of LSECs with the dynamic changes in the fibrotic liver microenvironment such as matrix rigidity, altered ECM protein profile, and cell-cell interactions to provide insight into the pivotal changes in LSEC physiology and the extent to which it mediates the progression of liver fibrosis. Establishing the molecular aspects of LSECs in the light of fibrotic microenvironment is valuable towards development of novel therapeutic and diagnostic targets of liver fibrosis.


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