• Biomolecules & Therapeutics
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• 제28권6호
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• pp.527-536
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• 2020

Liver fibrosis constitutes a significant health problem worldwide due to its rapidly increasing prevalence and the absence of specific and effective treatments. Growing evidence suggests that apoptosis-signal regulating kinase 1 (ASK1) is activated in oxidative stress, which causes hepatic inflammation and apoptosis, leading to liver fibrogenesis through a mitogen-activated protein kinase (MAPK) downstream signals. In this study, we investigated whether selonsertib, a selective inhibitor of ASK1, shows therapeutic efficacy for liver fibrosis, and elucidated its mechanism of action in vivo and in vitro. As a result, selonsertib strongly suppressed the growth and proliferation of hepatic stellate cells (HSCs) and induced apoptosis by increasing Annexin V and TUNEL-positive cells. We also observed that selonsertib inhibited the ASK1/MAPK pathway, including p38 and c-Jun N-terminal kinase (JNK) in HSCs. Interestingly, dimethylnitrosamine (DMN)-induced liver fibrosis was significantly alleviated by selonsertib treatment in rats. Furthermore, selonsertib reduced collagen deposition and the expression of extracellular components such as α-smooth muscle actin (α-SMA), fibronectin, and collagen type I in vitro and in vivo. Taken together, selonsertib suppressed fibrotic response such as HSC proliferation and extracellular matrix components by blocking the ASK1/MAPK pathway. Therefore, we suggest that selonsertib may be an effective therapeutic drug for ameliorating liver fibrosis.

• 대한임상검사과학회지
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• 제44권4호
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• pp.229-238
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• 2012

Cyclooxygenase(COX-2) is an inducible enzyme that catalyzes the synthesis of prostaglandins (PGs) from arachidonic acid. Over-expression of COX-2 has been reported to be associated with progressive hepatic fibrosis in chronic hepatic C infection and rat liver fibrosis induced by carbon tetrachloride($CCl_4$). Recently, it is well known that mast cell products can stimulate the proliferation of hepatic stellate cells and key players in liver fibrosis. But little is known regarding their role in $CCl_4$-induced liver fibrosis in rat. Our aim was to investigate the relation between COX-2 expression and mast cells during liver fibrosis after $CCl_4$ treatment. Thirty Wistar rats were divided into five groups (non-treated 0, 2, 4, 6 and 8-week after $CCl_4$-treatment). Reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry were used to assess the expression of ${\alpha}$-smooth muscle actin (${\alpha}$-SMA), collagen-1 and COX-2 in liver tissue from $CCl_4$-treated rats. The density of collagen and mast cells were determined using a computerized image analysis system in liver sections stained with picrosirius red and toluidine blue, respectively. The expression levels of ${\alpha}$-SMA, collagen-1 and COX-2 mRNA were significantly higher at 2 wk in $CCl_4$-treated groups than non-treated group. The number of mast cells in liver tissues increased gradually from 2 wk to 6 wk depending on the fibrosis severity but decreased abruptly at 8 wk. The significant increase of collagen-1 and ${\alpha}$-SMA mRNA expression in $CCl_4$-treated rats was continued until 6 wk while the COX-2 mRNA was significantly decreased at 8 wk. These results suggest that increased mast cells are closely associated with COX-2 over-expression during hepatic fibrogenesis of $CCl_4$-treated rats.

• Journal of Ginseng Research
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• 제41권3호
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• pp.392-402
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• 2017

Background: Previously, we reported that Korean Red Ginseng inhibited liver fibrosis in mice and reduced the expressions of fibrogenic genes in hepatic stellate cells (HSCs). The present study was undertaken to identify the major ginsenoside responsible for reducing the numbers of HSCs and the underlying mechanism involved. Methods: Using LX-2 cells (a human immortalized HSC line) and primary activated HSCs, MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide) assays were conducted to examine the cytotoxic effects of ginsenosides. $H_2O_2$ productions, glutathione contents, lactate dehydrogenase activities, mitochondrial membrane permeabilities, apoptotic cell subpopulations, caspase-3/-7 activities, transferase dUTP nick end labeling (TUNEL) staining, and immunoblot analysis were performed to elucidate the molecular mechanism responsible for ginsenoside-mediated cytotoxicity. Involvement of the AMP-activated protein kinase (AMPK)-related signaling pathway was examined using a chemical inhibitor and small interfering RNA (siRNA) transfection. Results and conclusion: Of the 11 ginsenosides tested, 20S-protopanaxadiol (PPD) showed the most potent cytotoxic activity in both LX-2 cells and primary activated HSCs. Oxidative stress-mediated apoptosis induced by 20S-PPD was blocked by N-acetyl-$\text\tiny L$-cysteine pretreatment. In addition, 20S-PPD concentration-dependently increased the phosphorylation of AMPK, and compound C prevented 20S-PPD-induced cytotoxicity and mitochondrial dysfunction. Moreover, 20S-PPD increased the phosphorylation of liver kinase B1 (LKB1), an upstream kinase of AMPK. Likewise, transfection of LX-2 cells with LKB1 siRNA reduced the cytotoxic effect of 20S-PPD. Thus, 20S-PPD appears to induce HSC apoptosis by activating LKB1-AMPK and to be a therapeutic candidate for the prevention or treatment of liver fibrosis.

• Toxicological Research
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• 제22권3호
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• pp.267-273
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• 2006

Tungtungmadic acid(3-caffeoyl, 4-dihydrocaffeoyl quinic acid: CDCQ) is a new chlorogenic acid derivative isolated from the Salicornia herbacea. The suppressive effects of CDCQ on the progress of acute carbon tetrachloride($CCl_4$)-induced hepatic fibrosis were investigated in mice. CDCQ significantly suppressed $CCl_4$-induced hepatic necrosis and inflammation, as determined by serum enzymatic activities of alanine and aspartate aminotransferase and serum TNF-$\alpha$ levels in a dose-dependent manner. In addition, increased hepatic lipid peroxidation and fibrosis after acute $CCl_4$ treatment were suppressed by the administration of CDCQ. CDCQ also significantly prevented the elevation of hepatic hydroxyproline and collagen content and ${\alpha}$-smooth muscle actin(${\alpha}$-SMA) expression in the liver of $CCl_4$-intoxicated mice. These results suggest that the suppressive effects of CDCQ against the acute $CCl_4$-induced hepatic fibrosis possibly related to its ability to block both hepatic inflammation and the activation of hepatic stellate cells.

• Biomolecules & Therapeutics
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• 제32권3호
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• pp.341-348
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• 2024

Endoplasmic reticulum (ER) stress plays a crucial role in liver diseases, affecting various types of hepatic cells. While studies have focused on the link between ER stress and hepatocytes as well as hepatic stellate cells (HSCs), the precise involvement of hepatic macrophages in ER stress-induced liver injury remains poorly understood. Here, we examined the effects of ER stress on hepatic macrophages and their role in liver injury. Acute ER stress led to the accumulation and activation of hepatic macrophages, which preceded hepatocyte apoptosis. Notably, macrophage depletion mitigated liver injury induced by ER stress, underscoring their detrimental role. Mechanistic studies revealed that ER stress stimulates macrophages predominantly via the PERK signaling pathway, regardless of its canonical substrate ATF4. hnRNPA1 has been identified as a crucial mediator of PERK-driven macrophage activation, as the overexpression of hnRNPA1 effectively reduced ER stress and suppressed pro-inflammatory activation. We observed that hnRNPA1 interacts with mRNAs that encode UPR-related proteins, indicating its role in the regulation of ER stress response in macrophages. These findings illuminate the cell type-specific responses to ER stress and the significance of hepatic macrophages in ER stress-induced liver injury. Collectively, the PERK-hnRNPA1 axis has been discovered as a molecular mechanism for macrophage activation, presenting prospective therapeutic targets for inflammatory hepatic diseases such as acute liver injury.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVI)
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• pp.221-221
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• 2005

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVII)
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• pp.231-231
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• 2005

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.222.2-223
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• 2002

• 대한약학회:학술대회논문집
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• 대한약학회 2000년도 춘계총회 및 학술대회
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• pp.211.2-211.2
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• 2000

• 한국식품과학회지
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• 제41권5호
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• pp.597-601
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• 2009

간성상세포(HSC)는 간섬유화와 간경변에 중요한 역할을 한다고 알려져 있다. 간손상에 의해 둥근 모양의 간성상세포는 활성화되어 세포외기질(ECM)을 생산하는 myofibroblast와 같은 모양으로 활성화 된다. 활성화된 간성상세포의 특징은 빠른 증식 속도와 collagen과 같은 세포외 기질의 생산이다. 활성화된 간성상 세포의 제거방법은 apoptosis를 유도하는 것이다. 가자 추출물은 정상 간세포(rat primary hepatocyte), 간세포주(HepG2) 및 활성화된 간성상세포주인 T-HSC/Cl-6에 $1,000{\mu}g/mL$의 농도까지 처리하여 세포독성을 확인하였다. 그 결과 hepatocyte나 HepG2에서는 최고 농도에서도 독성이 없었으나 T-HSC/Cl-6는 U-shape 모양으로 사멸하는 것을 확인 하였다. T-HSC/Cl-6의 사멸이 apoptosis에 의한 것인지를 Annexin-V/PI double staining을 통하여 확인한 결과 apoptosis에 의해 T-HSC/Cl-6의 사멸이 일어나는 것을 확인하였다.