scholarly journals Dysregulation of miR-21-associated miRNA regulatory networks by chronic ethanol consumption impairs liver regeneration

2021 ◽  
Author(s):  
Austin Parrish ◽  
Ankita Srivastava ◽  
Egle Juskeviciute ◽  
Jan B. Hoek ◽  
Rajanikanth Vadigepalli
Keyword(s):  
Liver Regeneration ◽  
Hepatic Stellate Cell ◽  
Mirna Expression ◽  
Hepatic Stellate Cells ◽  
Regulatory Networks ◽  
Stellate Cell ◽  
Stellate Cells ◽  
Chronic Ethanol ◽  
Regenerative Capacity

Impaired liver regeneration has been considered as a hallmark of progression of alcohol-associated liver disease. Our previous studies demonstrated that in vivo inhibition of the microRNA (miRNA) miR21 can restore regenerative capacity of the liver in chronic ethanol-fed animals. The present study focuses on the role of microRNA regulatory networks that are likely to mediate the miR-21 action. Rats were chronically fed an ethanol-enriched diet along with pair-fed control animals and treated with AM21 (anti-miR-21), a locked nucleic acid antisense to miR-21. Partial hepatectomy (PHx) was performed and miRNA expression profiling over the course of liver regeneration was assessed. Our results showed dynamic expression changes in several miRNAs post PHx, notably with altered miRNA expression profiles between ethanol versus control groups. We found that in vivo inhibition of miR-21 led to correlated differential expression of miR-340-5p, and anti-correlated expression of miR-365, let-7a, miR-1224 and miR-146a across all sample groups post PHx. Gene set enrichment analysis identified a miRNA signature significantly associated with hepatic stellate cell activation within whole-liver tissue data. We hypothesized that at least part of the PHx-induced miRNA network changes responsive to miR-21 inhibition is localized to hepatic stellate cells. We validated this hypothesis using AM21 and TGF-β treatments in LX-2 human hepatic stellate cells in culture, and measured expression levels of select miRNAs by quantitative RT-PCR. Based on the in vivo and in vitro results, we propose a hepatic stellate cell miRNA regulatory network as contributing to the restoration of liver regenerative capacity by miR-21 inhibition.

scholarly journals Identification of GDF15 as A Pro-Fibrotic Factor in Mouse Liver Fibrosis Progression

2021 ◽  
Author(s):  
Peng Qi ◽  
Ming-Ze Ma ◽  
Jing-Hua Kuai
Keyword(s):  
Carbon Tetrachloride ◽  
Liver Fibrosis ◽  
Hepatic Stellate Cell ◽  
Hepatic Stellate Cells ◽  
Liver Tissue ◽  
Cell Activation ◽  
Stellate Cell ◽  
Neutralizing Antibody ◽  
Stellate Cells ◽  
Fibrosis Progression

Abstract Aim:To elucidate the inhibitory role of growth differentiation factor 15 (GDF15) in liver fibrosis and its possible activation mechanism in hepatic stellate cells of mice.Methods:We generated a GDF15-neutralizing antibody that can inhibit TGF-β1-induced activation of the TGF-β/Smad2/3 pathway in LX-2 cells. All the mice in this study were induced by carbon tetrachloride and thioacetamide. In addition, primary hepatic stellate cells from mice were isolated from fresh livers using Nycodenz density gradient separation. The severity and extent of liver fibrosis in mice were evaluated by Sirius Red and Masson staining. The effect of GDF15 on the activation of the TGF-β pathway was detected using dual-luciferase reporter assays and Western blotting assays.Results:The expression of GDF15 in cirrhotic liver tissue was higher than that in normal liver tissue. Blocking GDF15 with a neutralizing antibody resulted in a delay in primary hepatic stellate cell activation and remission of liver fibrosis induced by carbon tetrachloride or thioacetamide. Meanwhile, TGF-β pathway activation was partly inhibited by a GDF15-neutralizing antibody in primary hepatic stellate cells. These results indicated that GDF15 plays an important role in regulating HSC activation and liver fibrosis progression.Conclusions:The inhibition of GDF15 attenuates chemical-inducible liver fibrosis and delays hepatic stellate cell activation, and this effect is probably mainly attributed to its regulatory role in TGF-β signalling.

scholarly journals Alpha-single chains of collagen type VI inhibit the fibrogenic effects of triple helical collagen VI in hepatic stellate cells

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0254557
Author(s):  
Christian Freise ◽  
Hyunho Lee ◽  
Christopher Chronowski ◽  
Doug Chan ◽  
Jessica Cziomer ◽  
...  
Keyword(s):  
Hepatic Stellate Cells ◽  
Collagen Type ◽  
Stellate Cell ◽  
Smooth Muscle Actin ◽  
Stellate Cells ◽  
Collagen Type I ◽  
Serum Starvation ◽  
Type I ◽  
Linear Peptide

The interaction of extracellular matrix (ECM) components with hepatic stellate cells (HSCs) is thought to perpetuate fibrosis by stimulating signaling pathways that drive HSC activation, survival and proliferation. Consequently, disrupting the interaction between ECM and HSCs is considered a therapeutical avenue although respective targets and underlying mechanisms remain to be established. Here we have interrogated the interaction between type VI collagen (CVI) and HSCs based on the observation that CVI is 10-fold upregulated during fibrosis, closely associates with HSCs in vivo and promotes cell proliferation and cell survival in cancer cell lines. We exposed primary rat HSCs and a rat hepatic stellate cell line (CFSC) to soluble CVI and determined the rate of proliferation, apoptosis and fibrogenesis in the absence of any additional growth factors. We find that CVI in nanomolar concentrations prevents serum starvation-induced apoptosis. This potent anti-apoptotic effect is accompanied by induction of proliferation and acquisition of a pronounced pro-fibrogenic phenotype characterized by increased α-smooth muscle actin, TGF-β, collagen type I and TIMP-1 expression and diminished proteolytic MMP-13 expression. The CVI-HSC interaction can be disrupted with the monomeric α2(VI) and α3(VI) chains and abrogates the activating CVI effects. Further, functional relevant α3(VI)—derived 30 amino acid peptides lead to near-complete inhibition of the CVI effect. In conclusion, CVI serves as a potent mitogen and activating factor for HSCs. The antagonistic effects of the CVI monomeric chains and peptides point to linear peptide sequences that prevent activation of CVI receptors which may allow a targeted antifibrotic therapy.

Lycopene inhibits hepatic stellate cell activation and modulates cellular lipid storage and signaling

2019 ◽  
Vol 10 (4) ◽  
pp. 1974-1984 ◽  
Author(s):  
Monique de Barros Elias ◽  
Felipe Leite Oliveira ◽  
Fatima Costa Rodrigues Guma ◽  
Renata Brum Martucci ◽  
Radovan Borojevic ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
Hepatic Stellate Cell ◽  
Hepatic Stellate Cells ◽  
Cell Activation ◽  
Stellate Cell ◽  
Stellate Cells ◽  
Lipid Storage ◽  
Cellular Lipid ◽  
Perivascular Cells ◽  
Hepatic Stellate Cell Activation

Hepatic stellate cells are liver-specific perivascular cells, identified as the major source of collagen in liver fibrosis, following their activation and conversion to myofibroblast-like cells.

scholarly journals Platelet Interactions with Liver Sinusoidal Endothelial Cells and Hepatic Stellate Cells Lead to Hepatocyte Proliferation

Cells ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 1243 ◽  
Author(s):  
Jeremy Meyer ◽  
Alexandre Balaphas ◽  
Pierre Fontana ◽  
Philippe Morel ◽  
Simon C. Robson ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Liver Regeneration ◽  
Partial Hepatectomy ◽  
Hepatic Stellate Cells ◽  
Stellate Cells ◽  
Hepatocyte Proliferation ◽  
Liver Sinusoidal Endothelial Cells ◽  
Hepatocyte Growth

(1) Background: Platelets were postulated to constitute the trigger of liver regeneration. The aim of this study was to dissect the cellular interactions between the various liver cells involved in liver regeneration and to clarify the role of platelets. (2) Methods: Primary mouse liver sinusoidal endothelial cells (LSECs) were co-incubated with increasing numbers of resting platelets, activated platelets, or platelet releasates. Alterations in the secretion of growth factors were measured. The active fractions of platelet releasates were characterized and their effects on hepatocyte proliferation assessed. Finally, conditioned media of LSECs exposed to platelets were added to primary hepatic stellate cells (HSCs). Secretion of hepatocyte growth factor (HGF) and hepatocyte proliferation were measured. After partial hepatectomy in mice, platelet and liver sinusoidal endothelial cell (LSEC) interactions were analyzed in vivo by confocal microscopy, and interleukin-6 (IL-6) and HGF levels were determined. (3) Results: Co-incubation of increasing numbers of platelets with LSECs resulted in enhanced IL-6 secretion by LSECs. The effect was mediated by the platelet releasate, notably a thermolabile soluble factor with a molecular weight over 100 kDa. The conditioned medium of LSECs exposed to platelets did not increase proliferation of primary hepatocytes when compared to LSECs alone but stimulated hepatocyte growth factor (HGF) secretion by HSCs, which led to hepatocyte proliferation. Following partial hepatectomy, in vivo adhesion of platelets to LSECs was significantly increased when compared to sham-operated mice. Clopidogrel inhibited HGF secretion after partial hepatectomy. (4) Conclusion: Our findings indicate that platelets interact with LSECs after partial hepatectomy and activate them to release a large molecule of protein nature, which constitutes the initial trigger for liver regeneration.

Influence of caveolin on constitutively activated recombinant eNOS: insights into eNOS dysfunction in BDL rat liver

2003 ◽  
Vol 285 (3) ◽  
pp. G652-G660 ◽  
Author(s):  
H. Hendrickson ◽  
S. Chatterjee ◽  
S. Cao ◽  
M. Morales Ruiz ◽  
W. C. Sessa ◽  
...  
Keyword(s):  
Rat Liver ◽  
Hepatic Stellate Cells ◽  
Fluorescent Protein ◽  
Stellate Cell ◽  
Active Form ◽  
Stellate Cells ◽  
Liver Cells ◽  
No Production

Diminished endothelial nitric oxide (NO) synthase (eNOS)-derived NO production from the hepatic vascular endothelium contributes to hepatic vasoconstriction in portal hypertension. The aim of this study was to examine the mechanism of this process by testing the influence of a constitutively active form of eNOS (S1179DeNOS) in both primary and propagated liver cells in vitro and in the sham and bile duct ligated (BDL) rat liver in vivo, using an adenoviral vector encoding green fluorescent protein (AdGFP) and S1179DeNOS (AdS1179DeNOS). AdS1179DeNOS transduction augmented basal and agonist-stimulated NO generation in nonparenchymal liver cells. Sham rats transduced in vivo with AdS1179DeNOS evidenced a decreased pressor response to incremental doses of the vasoconstrictor methoxamine compared with sham rats transduced with AdGFP. However, BDL rats transduced with AdS1179DeNOS did not display improved vasodilatory responses as evidenced by similar flow-dependent pressure increases to that observed in BDL rats transduced with AdGFP, despite similar levels of viral transgene expression. We next examined the influence of the eNOS inhibitory protein caveolin on S1179DeNOS dysfunction in cirrhotic liver. Immunogold electron microscopic analysis of caveolin in BDL liver demonstrated prominent expression not only in liver endothelial cells, but also in hepatic stellate cells. In vitro studies in the LX2 hepatic stellate cell line demonstrate that caveolin precipitates recombinant S1179DeNOS in LX2 cells, that recombinant S1179DeNOS coprecipitates caveolin, and that binding is enhanced in the presence of overexpression of caveolin. Furthermore, caveolin overexpression inhibits recombinant S1179DeNOS activity. These studies indicate that recombinant S1179DeNOS protein functions appropriately in normal liver cells and tissue but evidences dysfunction in the cirrhotic rat liver and that caveolin expression and inhibition in BDL nonparenchymal cells, including hepatic stellate cells, may account for this dysfunction.

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