Serine Protease HtrA2/Omi Deficiency Impairs Mitochondrial Homeostasis and Promotes Hepatic Fibrogenesis via Activation of Hepatic Stellate Cells

The loss of mitochondrial function impairs intracellular energy production and potentially results in chronic liver disease. Increasing evidence suggests that mitochondrial dysfunction in hepatocytes contributes to the activation of hepatic stellate cells (HSCs), thereby resulting in hepatic fibrogenesis. High-temperature requirement protein A2 (HtrA2/Omi), a mitochondrial serine protease with various functions, is responsible for quality control in mitochondrial homeostasis. However, little information is available regarding its role in mitochondrial damage during the development of liver fibrosis. This study examined whether HtrA2/Omi regulates mitochondrial homeostasis in hepatocyte during the development of hepatic fibrogenesis. In this study, we demonstrated that HtrA2/Omi expression considerably decreased in liver tissues from the CCl4-induced liver fibrotic mice model and from patients with liver cirrhosis. Knockdown of HtrA2/Omi in hepatocytes induced the accumulation of damaged mitochondria and provoked mitochondrial reactive oxygen species (mtROS) stress. We further show that the damaged mtDNA isolated from HtrA2/Omi-deficient hepatocytes as a form of damage-associated molecular patterns can induce HSCs activation. Moreover, we found that motor neuron degeneration 2-mutant mice harboring the missense mutation Ser276Cys in the protease domain of HtrA2/Omi displayed altered mitochondrial morphology and function, which increased oxidative stress and promoted liver fibrosis. Conversely, the overexpression of HtrA2/Omi via hydrodynamics-based gene transfer led to the antifibrotic effects in CCl4-induced liver fibrosis mice model through decreasing collagen accumulation and enhancing anti-oxidative activity by modulating mitochondrial homeostasis in the liver. These results suggest that suppressing HtrA2/Omi expression promotes hepatic fibrogenesis via modulating mtROS generation, and these novel mechanistic insights involving the regulation of mitochondrial homeostasis by HtrA2/Omi may be of importance for developing new therapeutic strategies for hepatic fibrosis.

Download Full-text

Transforming growth factor beta-induced Foxo3a acts as a profibrotic mediator in hepatic stellate cells

Toxicological Sciences ◽

10.1093/toxsci/kfaa185 ◽

2020 ◽

Author(s):

Seung Jung Kim ◽

Kyu Min Kim ◽

Ji Hye Yang ◽

Sam Seok Cho ◽

Eun Hee Jeong ◽

...

Keyword(s):

Liver Fibrosis ◽

Transforming Growth Factor Beta ◽

Hepatic Stellate Cells ◽

Transforming Growth Factor ◽

Smooth Muscle Actin ◽

Stellate Cells ◽

Forkhead Transcription Factor ◽

Hepatic Fibrogenesis ◽

Duct Ligation ◽

Nuclear Levels

Abstract Hepatic stellate cells (HSCs) are major contributors to hepatic fibrogenesis facilitating liver fibrosis. FoxO3a is a member of the forkhead transcription factor family, which mediates cell proliferation and differentiation. However, the expression and function of FoxO3a during HSC activation remain largely unknown. FoxO3a overexpression was related to fibrosis in patients, and its expression was colocalized with desmin or α-smooth muscle actin, representative HSC markers. We also observed upregulated FoxO3a levels in two animal hepatic fibrosis models, a carbon tetrachloride (CCl4)-injected model and a bile duct ligation model. In addition, TGF-β treatment in mouse primary HSCs or LX-2 cells elevated FoxO3a expression. When FoxO3a was upregulated by TGF-β in LX-2 cells, both the cytosolic and nuclear levels of FoxO3a increased. In addition, we found that the induction of FoxO3a by TGF-β was due to both transcriptional and proteasome-dependent mechanisms. Moreover, FoxO3a overexpression promoted TGF-β-mediated Smad activation. Furthermore, FoxO3a increased fibrogenic gene expression, which was reversed by FoxO3a knockdown. TGF-β-mediated FoxO3a overexpression in HSCs facilitated hepatic fibrogenesis, suggesting that FoxO3a may be a novel target for liver fibrosis prevention and treatment.

Download Full-text

Inhibition of Mastermind-like 1 alleviates liver fibrosis induced by carbon tetrachloride in rats

Experimental Biology and Medicine ◽

10.1177/1535370218810892 ◽

2018 ◽

Vol 243 (14) ◽

pp. 1099-1108

Author(s):

Shaoping Zheng ◽

Yixiong Chen ◽

Shaojiang Zheng ◽

Zhihui He ◽

Zhihong Weng

Keyword(s):

Carbon Tetrachloride ◽

Liver Fibrosis ◽

Hepatic Fibrosis ◽

Hepatic Stellate Cells ◽

Stellate Cells ◽

Underlying Mechanism ◽

Signal Pathways ◽

Fibrotic Liver ◽

Hepatic Fibrogenesis ◽

Signal Transductions

Mastermind-like 1 (MAML1) functions in critical transcriptional coactivation in Notch and Wnt/β-catenin signal pathways, which participate in hepatic fibrosis. This study is aimed to reveal the potential role of MAML1 in liver fibrosis and identify its underlying mechanism. In present research, the enhanced expression of MAML1 was found in the fibrotic liver tissues in carbon tetrachloride (CCl4)-induced hepatic fibrosis in rats, and MAML1 expression increased gradually during the activation of hepatic stellate cells (HSCs) isolated from the normal rat. Further studies showed that blocking MAML1 expression efﬁciently decreased the expression of α-SMA and collagen I (Col1a1) in HSCs. Interestingly, MAML1 may modulate HSCs activation via interrupting both Notch and Wnt/β-catenin signal transductions, and the inhibition of MAML1 by a recombinant adeno-associated virus type 1 vector carrying shRNA targeting MAML1 alleviated CCl4-induced hepatic fibrosis in rats. These findings suggest that the selective regulation of MAML1 expression may be a feasible therapeutic approach to reverse liver fibrosis. Impact statement Liver fibrosis is a common wound-healing response to all kinds of liver injuries. Hepatic stellate cells (HSCs) activation is the key event during liver fibrogenesis. Thus, the elucidation of mechanisms for regulating HSCs activation is helpful for identifying novel anti-fibrotic targets and strategies. MAML1, an important component of Notch signal, functions in critical transcriptional coactivation in the Notch and Wnt/β-catenin signal pathways. In the present study, we investigated the potential function of MAML1 during hepatic fibrogenesis in rats. Our results demonstrated that MAML1 participates in liver fibrosis through modulating HSCs activation via interrupting both the Notch and Wnt/β-catenin signal transductions. Additionally, the inhibition of MAML1 markedly attenuated CCl4-induced hepatic fibrogenesis in rats. Our results shed a light for the exploitation of a new therapeutic strategy for hepatic fibrosis via targeting MAML1.

Download Full-text

Activated Hepatic Stellate Cells Induce Infiltration and Formation of CD163+ Macrophages via CCL2/CCR2 Pathway

10.21203/rs.3.rs-28626/v1 ◽

2020 ◽

Author(s):

Sujuan Xi ◽

Xiaoyan Zheng ◽

Yuming Jiang ◽

Yuankai Wu ◽

Jiao Gong ◽

...

Keyword(s):

Liver Fibrosis ◽

Hepatic Stellate Cells ◽

Stellate Cells ◽

Immunofluorescence Assay ◽

M2 Macrophage ◽

Staining Score ◽

Activated Hepatic Stellate Cells ◽

High Level ◽

And Function

Abstract Background: Growing evidence indicates that activated hepatic stellate cells (aHSCs) play unexpected roles in regulating immune cells’ function during liver fibrosis. Macrophages feature with inducible plasticity according to the circumstances while patrol for potential pathogens. However, studies seldom investigate whether and how the aHSCs regulate the phenotype and function of macrophages during liver fibrosis. Methods: 96 patients with different stages of liver fibrosis were involved in our study. Metavir score system was used to evaluate the degree of fibrosis. The expression of hepatic CCL2 and CD163 were detected by immunohistochemistry, and the relationship among CD163, CCL2, and fibrosis scores were explored. We co-cultured the aHSCs and THP-1-derived M0-type macrophages (M0MФ) to observe whether aHSCs modulate the expression of CD163 on macrophages in vitro. Furthermore, we treated the M0MФ with aHSCs’ supernatant and investigated the production of CCL2 in aHSCs by ELISA and immunofluorescence assay. To explore whether CCL2/CCR2 axis plays a crucial role in macrophage phenotypic changes during liver fibrosis, we used recombinant CCL2 and its specific receptor antagonist. Moreover, we employed LX2 system to confirm our results. Results: We found that hepatic M2 macrophages (CD163+) infiltration increased in different stages of liver fibrosis (F0-1: 34.95±18.12; F2-3: 77.57±32.48; F4: 99.62±40.84, F0-1 vs. F2-3, P<0.001; F2-3 vs. F4, P=0.074). After in vitro co-cultured with aHSCs, the macrophages expressed higher levels of CD163 (29.5±6.1% vs. 2.7±1.1%) as well as CD206 (28.0±4.2% vs. 2.4±1.2%) compared with the control. Then we found aHSC supernatant up-regulated the expression of CD163 (26.1±2.8%) and CD206 (25.8±3.8%) on macrophages independently. We noted aHSCs’ supernatant contained a high level of CCL2, which increased dramatically while TGF-β stimulation. Meanwhile, CCL2 staining score increased with the progress of fibrosis ( N: 23.26±13.85; F1: 4 8.56±19.18; F2: 58.25±16.24; F3: 81.32±18.48; F4: 110.93±24.75). Intriguingly, CCL2 significantly up-regulated the expression of CD163 (27.6±7.0%) and CD206 (26.5±5.1%) on macrophages besides inducing their aggregation. Results were confirmed with LX2 co-culture system. Conclusions: (1) The expression of M2 macrophage marker CD163 increased significantly during the progress of liver fibrosis and associated with fibrosis severity. (2) AHSCs can recruit macrophages and induce their M2 phenotypic transformation through CCL2/CCR2 pathway.

Download Full-text

Specific Overexpression of Mitofusin-2 in Hepatic Stellate Cells Ameliorates Liver Fibrosis in Mice Model

Human Gene Therapy ◽

10.1089/hum.2019.153 ◽

2020 ◽

Vol 31 (1-2) ◽

pp. 103-109 ◽

Cited By ~ 1

Author(s):

Hanzhang Zhu ◽

Yuqiang Shan ◽

Ke Ge ◽

Jun Lu ◽

Wencheng Kong ◽

...

Keyword(s):

Liver Fibrosis ◽

Hepatic Stellate Cells ◽

Stellate Cells ◽

Mice Model ◽

Mitofusin 2

Download Full-text

Targeting Myosin 1c Inhibits Murine Hepatic Fibrogenesis

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00105.2021 ◽

2021 ◽

Author(s):

Ehtesham Arif ◽

Cindy Wang ◽

Marzena K Swiderska-Syn ◽

Ashish K Solanki ◽

Bushra Rahman ◽

...

Keyword(s):

Liver Fibrosis ◽

Hepatic Stellate Cells ◽

Tissue Injury ◽

Stellate Cells ◽

Cell Type ◽

Hepatic Fibrogenesis ◽

High Throughput Data ◽

Wound Healing Response ◽

Injury And Repair ◽

Geo Database

Myosin 1c (Myo1c) is an unconventional myosin that modulates signaling pathways involved in tissue injury and repair. In this study, we observed that Myo1c expression is significantly upregulated in human chronic liver disease such as nonalcoholic steatohepatitis (NASH) and in animal models of liver fibrosis. High throughput data from the GEO-database identified similar Myo1c upregulation in mice and human liver fibrosis. Notably, TGF-β stimulation to hepatic stellate cells (HSCs, the liver pericyte and key cell type responsible for the deposition of extracellular matrix upregulates Myo1c expression, while genetic depletion or pharmacological inhibition of Myo1c blunted TGF-β induced fibrogenic responses, resulting in repression of α-SMA and Col1α1 mRNA. Myo1c deletion also decreased fibrogenic processes such as cell proliferation, wound healing response and contractility when compared with vehicle treated HSCs. Importantly, phosphorylation of SMAD2 and SMAD3 were significantly blunted upon Myo1c inhibition in GRX cells as well as Myo1c-KO MEFs upon TGF-β stimulation. Using the genetic Myo1c knockout (Myo1c-KO) mice, we confirmed that Myo1c is critical for fibrogenesis as Myo1c-KO mice were resistant to CCl4 induced liver fibrosis. Histological and immunostaining analysis of liver sections showed that deposition of collagen fibers and α-SMA expression were significantly reduced in Myo1c-KO mice upon liver injury. Collectively, these results demonstrate that Myo1c-mediates hepatic fibrogenesis by modulating TGF-β signaling and suggest that inhibiting this process may have clinical application in treating liver fibrosis.

Download Full-text

Identification and localization of xylose-binding proteins as potential biomarkers for liver fibrosis/cirrhosis

Molecular BioSystems ◽

10.1039/c5mb00703h ◽

2016 ◽

Vol 12 (2) ◽

pp. 598-605 ◽

Cited By ~ 5

Author(s):

Yaogang Zhong ◽

Xiu-Xuan Sun ◽

Peixin Zhang ◽

Xinmin Qin ◽

Wentian Chen ◽

...

Keyword(s):

Liver Fibrosis ◽

Hepatic Stellate Cells ◽

Binding Proteins ◽

Stellate Cells ◽

Expression Levels ◽

Activated Hepatic Stellate Cells ◽

And Function ◽

Potential Biomarkers

In our recent study, we found that the expression levels of total xylose-binding proteins (XBPs) were up-regulated significantly in activated hepatic stellate cells (HSCs); however, the denomination, distribution, and function of the XBPs were uncharted.

Download Full-text

Activated Hepatic Stellate Cells Induce Infiltration and Formation of CD163+ Macrophages via CCL2/CCR2 Pathway

Frontiers in Medicine ◽

10.3389/fmed.2021.627927 ◽

2021 ◽

Vol 8 ◽

Author(s):

Sujuan Xi ◽

Xiaoyan Zheng ◽

Xiangyong Li ◽

Yuming Jiang ◽

Yuankai Wu ◽

...

Keyword(s):

Liver Fibrosis ◽

Hepatic Stellate Cells ◽

Stellate Cells ◽

M2 Macrophage ◽

Macrophage Phenotype ◽

Macrophage Marker ◽

Activated Hepatic Stellate Cells ◽

And Function ◽

M2 Phenotype

Background: Activated hepatic stellate cells (aHSCs) regulate the function of immune cells during liver fibrosis. As major innate cells in the liver, macrophages have inducible plasticity. Nevertheless, the mechanisms through which aHSCs regulate macrophages' phenotype and function during liver fibrosis and cirrhosis remain unclear. In this study, we examined the immunoregulatory function of aHSCs during liver fibrosis and explored their role in regulating macrophage phenotype and function.Methods: A total of 96 patients with different stages of chronic hepatitis B-related liver fibrosis were recruited in the study. Metavir score system was used to evaluate the degree of fibrosis. The expression of hepatic CCL2 and M2 phenotype macrophage marker CD163 were detected by immunohistochemistry, and the relationship among hepatic CD163, CCL2, and fibrosis scores were also explored. In the in vitro model, the aHSCs isolated from human liver tissues and THP-1-derived M0-type macrophages (M0MΦ) were co-cultured to observe whether and how aHSCs regulate the phenotype and function of macrophages. To explore whether CCL2/CCR2 axis has a crucial role in macrophage phenotypic changes during liver fibrosis, we treated the M0MΦ with recombinant human CCL2 or its specific receptor antagonist INCB-3284. Furthermore, we used LX2 and TGF-β-activated LX2 to mimic the different activation statuses of aHSCs to further confirm our results.Results: In patients, the infiltration of M2 macrophages increased during the progression of liver fibrosis. Intriguingly, as a key molecule for aHSC chemotactic macrophage aggregation, CCL2 markedly up-regulated the expression of CD163 and CD206 on the macrophages, which was further confirmed by adding the CCR2 antagonist (INCB 3284) into the cell culture system. In addition, the TGF-β stimulated LX2 further confirmed that aHSCs up-regulate the expression of CD163 and CD206 on macrophages. LX2 stimulated with TGF-β could produce more CCL2 and up-regulate other M2 phenotype macrophage-specific markers, including IL-10, ARG-1, and CCR2 besides CD163 and CD206 at the gene level, indicating that the different activation status of aHSCs might affect the final phenotype and function of macrophages.Conclusions: The expression of the M2 macrophage marker increases during liver fibrosis progression and is associated with fibrosis severity. AHSCs can recruit macrophages through the CCL2/CCR2 pathway and induce M2 phenotypic transformation.

Download Full-text