scholarly journals Initiation of hepatic stellate cell activation extends into chronic liver disease

2021 ◽  
Vol 12 (12) ◽  
Author(s):  
Vincent De Smet ◽  
Nathalie Eysackers ◽  
Vincent Merens ◽  
Mina Kazemzadeh Dastjerd ◽  
Georg Halder ◽  
...  

AbstractActivated hepatic stellate cells (aHSC) are the main source of extra cellular matrix in liver fibrosis. Activation is classically divided in two phases: initiation and perpetuation. Currently, HSC-based therapeutic candidates largely focus on targeting the aHSCs in the perpetuation phase. However, the importance of HSC initiation during chronic liver disease (CLD) remains unclear. Here, we identified transcriptional programs of initiating and activated HSCs by RNA sequencing, using in vitro and in vivo mouse models of fibrosis. Importantly, we show that both programs are active in HSCs during murine and human CLD. In human cirrhotic livers, scar associated mesenchymal cells employ both transcriptional programs at the single cell level. Our results indicate that the transcriptional programs that drive the initiation of HSCs are still active in humans suffering from CLD. We conclude that molecules involved in the initiation of HSC activation, or in the maintenance of aHSCs can be considered equally important in the search for druggable targets of chronic liver disease.

2010 ◽  
Vol 6 (1) ◽  
pp. 45-68
Author(s):  
Samir A. El-Masry ◽  
Mona S. Gouida ◽  
Khalid M. El-azab ◽  
Mahmoud E Nasr

2020 ◽  
Vol 134 (16) ◽  
pp. 2189-2201
Author(s):  
Jessica P.E. Davis ◽  
Stephen H. Caldwell

Abstract Fibrosis results from a disordered wound healing response within the liver with activated hepatic stellate cells laying down dense, collagen-rich extracellular matrix that eventually restricts liver hepatic synthetic function and causes increased sinusoidal resistance. The end result of progressive fibrosis, cirrhosis, is associated with significant morbidity and mortality as well as tremendous economic burden. Fibrosis can be conceptualized as an aberrant wound healing response analogous to a chronic ankle sprain that is driven by chronic liver injury commonly over decades. Two unique aspects of hepatic fibrosis – the chronic nature of insult required and the liver’s unique ability to regenerate – give an opportunity for pharmacologic intervention to stop or slow the pace of fibrosis in patients early in the course of their liver disease. Two potential biologic mechanisms link together hemostasis and fibrosis: focal parenchymal extinction and direct stellate cell activation by thrombin and Factor Xa. Available translational research further supports the role of thrombosis in fibrosis. In this review, we will summarize what is known about the convergence of hemostatic changes and hepatic fibrosis in chronic liver disease and present current preclinical and clinical data exploring the relationship between the two. We will also present clinical trial data that underscores the potential use of anticoagulant therapy as an antifibrotic factor in liver disease.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Margret Paar ◽  
Vera H. Fengler ◽  
Daniel J. Rosenberg ◽  
Angelika Krebs ◽  
Rudolf E. Stauber ◽  
...  

AbstractHuman serum albumin (HSA) constitutes the primary transporter of fatty acids, bilirubin, and other plasma compounds. The binding, transport, and release of its cargos strongly depend on albumin conformation, which is affected by bound ligands induced by physiological and pathological conditions. HSA is both highly oxidized and heavily loaded with fatty acids and bilirubin in chronic liver disease. By employing small-angle X-ray scattering we show that HSA from the plasma of chronic liver disease patients undergoes a distinct opening compared to healthy donors. The extent of HSA opening correlates with clinically relevant variables, such as the model of end-stage liver disease score, bilirubin, and fatty acid levels. Although the mild oxidation of HSA in vitro does not alter overall structure, the alteration of patients’ HSA correlates with its redox state. This study connects clinical data with structural visualization of albumin dynamicity in solution and underlines the functional importance of albumin’s inherent flexibility.


2017 ◽  
Vol 7 ◽  
pp. S55-S56
Author(s):  
Emmanuelle Flatt ◽  
Cristina Cudalbu ◽  
Olivier Braissant ◽  
Stefan Mitrea ◽  
Dario Sessa ◽  
...  

2019 ◽  
Vol 10 (10) ◽  
Author(s):  
Wonbeak Yoo ◽  
Jaemin Lee ◽  
Kyung Hee Noh ◽  
Sangmin Lee ◽  
Dana Jung ◽  
...  

Abstract Progranulin (PGRN) is a cysteine-rich secreted protein expressed in endothelial cells, immune cells, neurons, and adipocytes. It was first identified for its growth factor-like properties, being implicated in tissue remodeling, development, inflammation, and protein homeostasis. However, these findings are controversial, and the role of PGRN in liver disease remains unknown. In the current study, we examined the effect of PGRN in two different models of chronic liver disease, methionine‐choline‐deficient diet (MCD)-induced non-alcoholic steatohepatitis (NASH) and carbon tetrachloride (CCl4)-induced liver fibrosis. To induce long-term expression of PGRN, PGRN-expressing adenovirus was delivered via injection into the tibialis anterior. In the CCl4-induced fibrosis model, PGRN showed protective effects against hepatic injury, inflammation, and fibrosis via inhibition of nuclear transcription factor kappa B (NF-κB) phosphorylation. PGRN also decreased lipid accumulation and inhibited pro-inflammatory cytokine production and fibrosis in the MCD-induced NASH model. In vitro treatment of primary macrophages and Raw 264.7 cells with conditioned media from hepatocytes pre-treated with PGRN prior to stimulation with tumor necrosis factor (TNF)-α or palmitate decreased their expression of pro-inflammatory genes. Furthermore, PGRN suppressed inflammatory and fibrotic gene expression in a cell culture model of hepatocyte injury and primary stellate cell activation. These observations increase our understanding of the role of PGRN in liver injury and suggest PGRN delivery as a potential therapeutic strategy in chronic inflammatory liver disease.


2020 ◽  
Vol 318 (2) ◽  
pp. G211-G224
Author(s):  
Denitra A. Breuer ◽  
Maria Cristina Pacheco ◽  
M. Kay Washington ◽  
Stephanie A. Montgomery ◽  
Alyssa H. Hasty ◽  
...  

Nonalcoholic steatohepatitis (NASH) has increased in Western countries due to the prevalence of obesity. Current interests are aimed at identifying the type and function of immune cells that infiltrate the liver and key factors responsible for mediating their recruitment and activation in NASH. We investigated the function and phenotype of CD8+ T cells under obese and nonobese NASH conditions. We found an elevation in CD8 staining in livers from obese human subjects with NASH and cirrhosis that positively correlated with α-smooth muscle actin, a marker of hepatic stellate cell (HSC) activation. CD8+ T cells were elevated 3.5-fold in the livers of obese and hyperlipidemic NASH mice compared with obese hepatic steatosis mice. Isolated hepatic CD8+ T cells from these mice expressed a cytotoxic IL-10-expressing phenotype, and depletion of CD8+ T cells led to significant reductions in hepatic inflammation, HSC activation, and macrophage accumulation. Furthermore, hepatic CD8+ T cells from obese and hyperlipidemic NASH mice activated HSCs in vitro and in vivo. Interestingly, in the lean NASH mouse model, depletion and knockdown of CD8+ T cells did not impact liver inflammation or HSC activation. We demonstrated that under obese/hyperlipidemia conditions, CD8+ T cell are key regulators of the progression of NASH, while under nonobese conditions they play a minimal role in driving the disease. Thus, therapies targeting CD8+ T cells may be a novel approach for treatment of obesity-associated NASH. NEW & NOTEWORTHY Our study demonstrates that CD8+ T cells are the primary hepatic T cell population, are elevated in obese models of NASH, and directly activate hepatic stellate cells. In contrast, we find CD8+ T cells from lean NASH models do not regulate NASH-associated inflammation or stellate cell activation. Thus, for the first time to our knowledge, we demonstrate that hepatic CD8+ T cells are key players in obesity-associated NASH.


2019 ◽  
Vol 114 (1) ◽  
pp. S18-S19
Author(s):  
Emmanuelle Flatt ◽  
Olivier Braissant ◽  
Stefanita Mitrea ◽  
Dario Sessa ◽  
Rolf Gruetter ◽  
...  

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Xin-Yi Xu ◽  
Yan Du ◽  
Xue Liu ◽  
Yilin Ren ◽  
Yingying Dong ◽  
...  

Abstract Background Hepatic fibrosis is a pathological response of the liver to a variety of chronic stimuli. Hepatic stellate cells (HSCs) are the major source of myofibroblasts in the liver. Follistatin like 1 (Fstl1) is a secreted glycoprotein induced by transforming growth factor-β1 (TGF-β1). However, the precise functions and regulation mechanisms of Fstl1 in liver fibrogenesis remains unclear. Methods Hepatic stellate cell (HSC) line LX-2 stimulated by TGF-β1, primary culture of mouse HSCs and a model of liver fibrosis induced by CCl4 in mice was used to assess the effect of Fstl1 in vitro and in vivo. Results Here, we found that Fstl1 was significantly up regulated in human and mouse fibrotic livers, as well as activated HSCs. Haplodeficiency of Fstl1 or blockage of Fstl1 with a neutralizing antibody 22B6 attenuated CCl4-induced liver fibrosis in vivo. Fstl1 modulates TGF-β1 classic Samd2 and non-classic JNK signaling pathways. Knockdown of Fstl1 in HSCs significantly ameliorated cell activation, cell migration, chemokines C-C Motif Chemokine Ligand 2 (CCL2) and C-X-C Motif Chemokine Ligand 8 (CXCL8) secretion and extracellular matrix (ECM) production, and also modulated microRNA-29a (miR29a) expression. Furthermore, we identified that Fstl1 was a target gene of miR29a. And TGF-β1 induction of Fstl1 expression was partially through down regulation of miR29a in HSCs. Conclusions Our data suggests TGF-β1-miR29a-Fstl1 regulatory circuit plays a key role in regulation the HSC activation and ECM production, and targeting Fstl1 may be a strategy for the treatment of liver fibrosis. Graphical abstract


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