Faculty Opinions recommendation of Differences in regulation of type I collagen synthesis in primary and passaged hepatic stellate cell cultures: the role of alpha5beta1-integrin.

Hepatic stellate cells (HSC) differ in their phenotype depending on the initiation and progression of their activation. Our hypothesis was that different mechanisms govern type I collagen synthesis depending on stage of HSC activation. We investigated the role of α5β1-integrin as a regulator of type I collagen gene COL1A1 expression in primary and passaged HSC cultures using transgenic mouse containing type I collagen gene COL1A1 promoter linked to the chloramphenicol acetyltransferase (CAT) reporter gene. The α5β1 protein levels increased during the activation and were highest in day 6 primary cultures but decreased in passaged HSC. CAT activity, reflecting COL1A1 expression, was upregulated by α5β1-integrin. Inhibition of α5β1-integrin by echistatin and blocking antibody resulted in reduced transgene activity only in early primary cultures (compared with the control, 53.3 ± 12% echistatin and 58.8 ± 7% blocking antibody, respectively, P < 0.05). Treatment of passaged HSC with either echistatin or blocking antibody had no effect. Fibronectin, an α5β1-integrin ligand, increased transgene activity in primary (210 ± 33%, P < 0.05) but not in passaged HSC cultures (119 ± 8%). This α5β1-integrin effect appears to be at least in part mediated by CCAAT enhancer binding protein-β (C/EBPβ), because fibronectin increased and α5-gene silencing by small interfering RNA decreased C/EBPβ levels. In addition, C/EBPβ knockout mice showed reduced type I collagen synthesis compared with wild-type littermates. Therefore α5β1-integrin is an important regulator of type I collagen production in early primary HSC cultures but appears to have no direct role once the HSC are fully activated.

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Establishment of an Immortalized Human Hepatic Stellate Cell Line to Develop Antifibrotic Therapies

Cell Transplantation ◽

10.3727/000000003108747064 ◽

2003 ◽

Vol 12 (5) ◽

pp. 499-507 ◽

Cited By ~ 36

Author(s):

Norikuni Shibata ◽

Takamasa Watanabe ◽

Teru Okitsu ◽

Masakiyo Sakaguchi ◽

Michihiko Takesue ◽

...

Keyword(s):

Cell Line ◽

Hepatic Stellate Cell ◽

Type I Collagen ◽

Replicative Senescence ◽

Stellate Cell ◽

Smooth Muscle Actin ◽

Population Doubling ◽

Type I ◽

Human Hepatic Stellate Cell ◽

Ifn Γ

Because human hepatic stellate cells (HSCs) perform a crucial role in the progress of hepatic fibrosis, it is of great value to establish an immortalized human cell line that exhibits HSC characteristics and grows well in tissue cultures for the development of antifibrotic therapies. Thus, we engineered an immortalized human hepatic stellate cell (HSC) line TWNT-4 by retrovirally inducing human telomerase reverse transcriptase (hTERT) into LI 90 cells established from a human liver mesenchymal tumor. Parental LI 90 entered replicative senescence, whereas TWNT-4 showed telomerase activity and proliferated for more than population doubling level (PDL) 200 without any crisis. TWNT-4 expressed platelet-derived growth factor-β receptor (PDGF-βR), α-smooth muscle actin (α-SMA), and type I collagen (α1) and was considered to be an activated form of HSCs. Treatment of TWNT-4 cells with either 100 U/ml of IFN-γ or 1 ng/ml of rapamycin (Rapa) for 14 days led to lower expression of type I collagen (α1) at RNA and protein levels. Exposure of TWNT-4 cells to both of IFN-γ (10 U/ml) and Rapa (0.1 ng/ml) for 14 days effectively decreased the expression of type I collagen (α1), PDGF-βR, and α-SMA expression and suppressed TGF-β1 secretion of TWNT-4 cells. We successfully induced apoptosis by transducing TNF-related apoptosis-inducing ligand (TRAIL) into TWNT-4 cells using adenovirus vectors Ad/GT-TRAIL and Ad/PGK-GV-17. These findings suggested that immortalized activated HSC line TWNT-4 would be a useful means to develop antifibrotic therapies.

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NP603, a novel and potent inhibitor of FGFR1 tyrosine kinase, inhibits hepatic stellate cell proliferation and ameliorates hepatic fibrosis in rats

AJP Cell Physiology ◽

10.1152/ajpcell.00452.2010 ◽

2011 ◽

Vol 301 (2) ◽

pp. C469-C477 ◽

Cited By ~ 26

Author(s):

Nan Lin ◽

Si Chen ◽

Weidong Pan ◽

Linan Xu ◽

Kunpeng Hu ◽

...

Keyword(s):

Tyrosine Kinase ◽

Hepatic Fibrosis ◽

Hepatic Stellate Cell ◽

Type I Collagen ◽

Kinase Inhibitor ◽

Stellate Cell ◽

Smooth Muscle Actin ◽

Type I ◽

Promising Therapeutic Approach ◽

The Impact

Fibroblast growth factor 2 (FGF-2) and its main receptor FGFR1 have been shown to promote hepatic stellate cell (HSC) activation and proliferation. However, scant information is available on the anti-fibrogenic activity of FGFR1 inhibitors. The aim of this study was to assess the impact of a selective FGFR1 tyrosine kinase inhibitor NP603 on HSC proliferation and hepatic fibrosis. We demonstrated that rat primary HSCs secreted significant amounts of FGF-2, and its tyrosine phosphorylation of FGFR1 was attenuated by NP603. NP603 inhibited HSC activaton by measuring the expression of α-smooth muscle actin (α-SMA) and the production of type I collagen using ELISA. Furthermore, NP603 (25 μM) in vitro strongly suppressed HSC growth induced by FGF-2 (10 ng/ml) and FCS. This effect correlated with the suppression of extracellular-regulated kinase (ERK) activity and its downstream targets cyclin D1 and p21. In addition, PO NP603 (20 mg·kg−1·day−1) administration significantly decreased hepatic collagen deposition and α-SMA expression in CCl4-treated rats. Collectively, these studies suggest that selective blocking of the FGFR1-mediated pathway could be a promising therapeutic approach for the treatment of hepatic fibrosis.

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Role of c-Jun N-terminal kinase and p38/activation protein-1 in interleukin-1β-mediated type I collagen synthesis in rat hepatic stellate cells

Apmis ◽

10.1111/j.1600-0463.2011.02816.x ◽

2011 ◽

Vol 120 (2) ◽

pp. 101-107 ◽

Cited By ~ 15

Author(s):

YAPING ZHANG ◽

XIXIAN YAO

Keyword(s):

Hepatic Stellate Cells ◽

Collagen Synthesis ◽

Type I Collagen ◽

Stellate Cells ◽

Interleukin 1Β ◽

Type I

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Dietary Flavonoid Hyperoside Induces Apoptosis of Activated Human LX-2 Hepatic Stellate Cell by Suppressing Canonical NF-κB Signaling

BioMed Research International ◽

10.1155/2016/1068528 ◽

2016 ◽

Vol 2016 ◽

pp. 1-10 ◽

Cited By ~ 9

Author(s):

Liwen Wang ◽

Zhiwei Yue ◽

Mengzheng Guo ◽

Lianying Fang ◽

Liang Bai ◽

...

Keyword(s):

Hepatic Stellate Cell ◽

Type I Collagen ◽

Stellate Cell ◽

Smooth Muscle Actin ◽

Binding Activity ◽

Type I ◽

Altered Expression ◽

Dna Binding Activity ◽

Dietary Flavonoid ◽

Induced Apoptosis

Hyperoside, an active compound found in plants of the generaHypericumandCrataegus, is reported to exhibit antioxidant, anticancer, and anti-inflammatory activities. Induction of hepatic stellate cell (HSC) apoptosis is recognized as a promising strategy for attenuation of hepatic fibrosis. In this study, we investigated whether hyperoside treatment can exert antifibrotic effects in human LX-2 hepatic stellate cells. We found that hyperoside induced apoptosis in LX-2 cells and decreased levels ofα-smooth muscle actin (α-SMA), type I collagen, and intracellular reactive oxygen species (ROS). Remarkably, hyperoside also inhibited the DNA-binding activity of the transcription factor NF-κB and altered expression levels of NF-κB-regulated genes related to apoptosis, including proapoptotic genesBcl-Xs,DR4,Fas, andFasLand anti-apoptotic genesA20,c-IAP1,Bcl-XL, andRIP1. Our results suggest that hyperoside may have potential as a therapeutic agent for the treatment of liver fibrosis.

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