scholarly journals Toll-Like Receptor Signaling and Liver Fibrosis

2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
Tomonori Aoyama ◽  
Yong-Han Paik ◽  
Ekihiro Seki
Keyword(s):  
Liver Fibrosis ◽  
Kupffer Cells ◽  
Hepatic Stellate Cells ◽  
Cell Activation ◽  
Stellate Cell ◽  
Inflammatory Cells ◽  
Stellate Cells ◽  
Cell Types ◽  
Tlr Signaling

Liver fibrosis occurs as a wound-healing scar response following acute and chronic liver inflammation including alcoholic liver disease, non-alcoholic steatohepatitis, hepatitis B and C, and autoimmune hepatitis. Myofibroblasts, mainly transdifferentiated from hepatic stellate cells, are pivotal cell types that produce fibrillar collagen. The activation of inflammatory cells, including Kupffer cells, is a crucial step for activating hepatic stellate cells. Toll-like receptors (TLRs) are pattern recognition receptors that sense pathogen-associated molecular patterns (PAMPs), which discriminate the products of microorganisms from the host. TLRs are expressed on Kupffer cells, endothelial cells, dendritic cells, biliary epithelial cells, hepatic stellate cells, and hepatocytes in the liver. TLR signaling induces potent innate immune responses in these cell types. The liver is constantly exposed to PAMPs, such as LPS and bacterial DNA through bacterial translocation because there is a unique anatomical link, the portal vein system between liver and intestine. Recent evidence demonstrates the role of TLRs in the activation of hepatic immune cells and stellate cells during liver fibrosis. Moreover, crosstalk between TLR4 signaling and TGF-βsignaling in hepatic stellate cells has been reported. This paper highlights the role of TLR signaling in stellate cell activation and the progression of liver fibrosis.

Possible Therapeutic Uses of Extracellular Vesicles for Reversion of Activated Hepatic Stellate Cells: Context and Future Perspectives

2021 ◽  
Vol 21 ◽  
Author(s):  
Fahim Rejanur Tasin ◽  
Debasish Halder ◽  
Chanchal Mandal
Keyword(s):  
Liver Fibrosis ◽  
Extracellular Vesicles ◽  
Hepatic Stellate Cells ◽  
Cell Activation ◽  
Stellate Cell ◽  
Stellate Cells ◽  
Target Cells ◽  
Fibrotic Liver ◽  
Paracrine Effects ◽  
Cell Therapies

: Liver fibrosis is one of the leading causes for cirrhotic liver disease and the lack of therapies to treat fibrotic liver is a major concern. Liver fibrosis is mainly occurred by activation of hepatic stellate cells and some stem cell therapies had previously reported for treatment. However, due to some problems with cell-based treatment, a safe therapeutic agent is vehemently sought by the researchers. Extracellular vesicles are cell-derived nanoparticles that are employed in several therapeutic approaches, including fibrosis, for their ability to transfer specific molecules in the target cells. In this review the possibilities of extracellular vesicles to inactivate stellate cells are summarized and discussed. According to several studies, extracellular vesicles from different sources can either put beneficial or detrimental effects by regulating the activation of stellate cells. Therefore, targeting extracellular vesicles for maximizing or inhibiting their production is a potential approach for fibrotic liver treatment. Extracellular vesicles from different cells can also inactivate stellate cells by carrying out the paracrine effects of those cells, working as the agents. They are also implicated as smart carrier of anti-fibrotic molecules when their respective parent cells are engineered to produce specific stellate cell-regulating substances. A number of studies showed stellate cell activation can be regulated by up/downregulation of specific proteins, and extracellular vesicle-based therapies can be an effective move to exploit these mechanisms. In conclusion, EVs are advantageous nano-carriers with the potential to treat fibrotic liver by inactivating activated stellate cells by various mechanisms.

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.

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 Role of cytoglobin, a novel radical scavenger, in stellate cell activation and hepatic fibrosis

2020 ◽  
Vol 26 (3) ◽  
pp. 280-293 ◽  
Author(s):  
Le Thi Thanh Thuy ◽  
Hoang Hai ◽  
Norifumi Kawada
Keyword(s):  
Liver Fibrosis ◽  
Hepatic Fibrosis ◽  
Cell Activation ◽  
Stellate Cell ◽  
Stellate Cells ◽  
Radical Scavenger ◽  
History Of Research ◽  
Duct Ligation ◽  
History Of

Cytoglobin (Cygb), a stellate cell-specific globin, has recently drawn attention due to its association with liver fibrosis. In the livers of both humans and rodents, Cygb is expressed only in stellate cells and can be utilized as a marker to distinguish stellate cells from hepatic fibroblast-derived myofibroblasts. Loss of Cygb accelerates liver fibrosis and cancer development in mouse models of chronic liver injury including diethylnitrosamine-induced hepatocellular carcinoma, bile duct ligation-induced cholestasis, thioacetamide-induced hepatic fibrosis, and choline-deficient L-amino acid-defined diet-induced non-alcoholic steatohepatitis. This review focuses on the history of research into the role of reactive oxygen species and nitrogen species in liver fibrosis and discusses the current perception of Cygb as a novel radical scavenger with an emphasis on its role in hepatic stellate cell activation and fibrosis.

scholarly journals Characterization of a stellate cell activation-associated protein (STAP) with peroxidase activity found in rat hepatic stellate cells.

2001 ◽  
Vol 276 (50) ◽  
pp. 47744
Author(s):  
Norifumi Kawada ◽  
Dan Bach Kristensen ◽  
Kinji Asahina ◽  
Kazuki Nakatani ◽  
Yukiko Minamiyama ◽  
...  
Keyword(s):  
Peroxidase Activity ◽  
Hepatic Stellate Cells ◽  
Cell Activation ◽  
Stellate Cell ◽  
Stellate Cells

scholarly journals Nuclear Cathepsin F Regulates Activation Markers in Rat Hepatic Stellate Cells

2008 ◽  
Vol 19 (10) ◽  
pp. 4238-4248 ◽  
Author(s):  
Gunter Maubach ◽  
Michelle Chin Chia Lim ◽  
Lang Zhuo
Keyword(s):  
Hepatic Stellate Cells ◽  
Cell Activation ◽  
Stellate Cell ◽  
Stellate Cells ◽  
Activation Process ◽  
Type I ◽  
Activation Markers ◽  
Nuclear Activity ◽  
Cystatin B ◽  
Cathepsin F

Activation of hepatic stellate cells during liver fibrosis is a major event facilitating an increase in extracellular matrix deposition. The up-regulation of smooth muscle α-actin and collagen type I is indicative of the activation process. The involvement of cysteine cathepsins, a class of lysosomal cysteine proteases, has not been studied in conjunction with the activation process of hepatic stellate cells. Here we report a nuclear cysteine protease activity partially attributed to cathepsin F, which co-localizes with nuclear speckles. This activity can be regulated by treatment with retinol/palmitic acid, known to reduce the hepatic stellate cell activation. The treatment for 48 h leads to a decrease in activity, which is coupled to an increase in cystatin B and C transcripts. Cystatin B knockdown experiments during the same treatment confirm the regulation of the nuclear activity by cystatin B. We demonstrate further that the inhibition of the nuclear activity by E-64d, a cysteine protease inhibitor, results in a differential regulation of smooth muscle α-actin and collagen type I transcripts. On the other hand, cathepsin F small interfering RNA transfection leads to a decrease in nuclear activity and a transcriptional down-regulation of both activation markers. These findings indicate a possible link between nuclear cathepsin F activity and the transcriptional regulation of hepatic stellate cell activation markers.

scholarly journals SAT-LB101 Loss of GLP-2R Signaling Activates Hepatic Stellate Cells and Exacerbates Diet-Induced Steatohepatitis in Mice

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Shai Z Fuchs ◽  
Bernardo Yusta ◽  
Laurie Baggio ◽  
Elodie Varin ◽  
Dianne Matthews ◽  
...  
Keyword(s):  
Hepatic Stellate Cells ◽  
Cell Activation ◽  
Ex Vivo ◽  
Stellate Cell ◽  
Intestinal Failure ◽  
Stellate Cells ◽  
Cell Fractionation ◽  
Hepatic Inflammation ◽  
Hepatic Lipid Accumulation ◽  
Gut Hormone

Abstract A GLP-2 analogue is used in individuals with intestinal failure at risk for liver disease, yet the hepatic actions of GLP-2 are not understood. Treatment of high fat diet (HFD)-fed mice with GLP-2 did not modify the development of hepatosteatosis or hepatic inflammation. In contrast, Glp2r-/- mice exhibited increased hepatic lipid accumulation, deterioration in glucose tolerance, and upregulation of biomarkers of hepatic inflammation. Both mouse and human liver expressed the canonical GLP-2R, and hepatic Glp2r expression was upregulated in mice with hepatosteatosis. Cell fractionation localized the Glp2r to hepatic stellate cells (HSC), and markers of HSC activation and fibrosis were increased in livers from Glp2r-/- mice. Moreover, GLP-2 directly modulated gene expression in isolated HSCs ex vivo. Taken together, these findings define an essential role for the GLP-2R in hepatic adaptation to nutrient excess and unveil a gut hormone-HSC axis, linking GLP-2R signaling to control of hepatic stellate cell activation.

scholarly journals The Role of Signal Transducer and Activator of Transcription 5 and Transforming Growth Factor-β1 in Hepatic Fibrosis Induced by Chronic Hepatitis C Virus Infection in Egyptian Patients

2018 ◽  
Vol 27 (2) ◽  
pp. 115-121
Author(s):  
Mona A. Abu El Makarem ◽  
Ghada M. El-Sagheer ◽  
Moustafa A. Abu El-Ella
Keyword(s):  
Chronic Hepatitis ◽  
Hepatitis C ◽  
Liver Fibrosis ◽  
Hepatic Stellate Cells ◽  
Stellate Cells ◽  
Serum Levels ◽  
Signal Transducer ◽  
Egyptian Patients ◽  
Tgf Β1

Objective: To investigate the possible role of signal transducer and activator of transcription 5 (STAT5) in the pathogenesis of liver fibrosis in Egyptian patients with chronic hepatitis C (CHC) virus infection and its relation to hepatic stellate cells (HSC). Subjects and Methods: Sixty-five patients (46 males and 19 females) were divided into 4 groups based on the severity of fibrosis as detected by Fibroscan as follows: F1, n = 15; F2, n = 21; F3, n = 13; and F4, n = 16. Twenty age- and gender-matched healthy persons volunteered as controls. The serum levels of STAT5, TGF-β1, α-smooth muscle actin (α-SMA), fasting blood sugar, and fasting insulin, as well as homeostasis model assessment of insulin resistance (HOMA-IR), were determined and compared for all groups. The usefulness of the studied serum biomarkers for predicting liver fibrosis was evaluated using a receiver operating characteristic curve. Results: Serum levels of STAT5 were significantly lower in patients compared to controls (9.69 ± 5.62 vs. 14.73 ± 6.52, p ≤ 0.001); on the contrary, TGF-β1, α-SMA, and HOMA-IR were significantly higher in patients compared to controls (mean: 1,796.04 vs. 1,636.94; 14.94 vs. 8.1; and 7.91 vs. 4.18; p ≤ 0.01 and 0.001, respectively). TGF-β1 and α-SMA showed a progressive increase with advancing severity of hepatic fibrosis (mean TGF-β1: 2,058.4 in F1-F2 and 1,583.8 in F3-F4, p ≤ 0.04; mean α-SMA: 13.59 in F1-F2 and 16.62 in F3-F4, p ≤ 0.05). STAT5 had a significant negative correlation with TGF-β1 (p ≤ 0.001), while no correlation was detected with α-SMA (p ≤ 0.8). Conclusions: STAT5 may play a significant role in hepatic fibrogenesis through the induction of TGF-β1 but not through the activation of hepatic stellate cells.

The Role of Galectin-3 in Stellate Cell Activation and Liver Fibrosis

2012 ◽  
pp. 391-395 ◽  
Author(s):  
Joy X. Jiang ◽  
Xiangling Chen ◽  
Hiroo Fukada ◽  
Dan K. Hsu ◽  
Fu-tong Liu ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
Cell Activation ◽  
Stellate Cell ◽  
Galectin 3
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