scholarly journals The cGAS-STING Pathway: Novel Perspectives in Liver Diseases

2021 ◽  
Vol 12 ◽  
Author(s):  
Dongwei Xu ◽  
Yizhu Tian ◽  
Qiang Xia ◽  
Bibo Ke

Liver diseases represent a major global health burden accounting for approximately 2 million deaths per year worldwide. The liver functions as a primary immune organ that is largely enriched with various innate immune cells, including macrophages, dendritic cells, neutrophils, NK cells, and NKT cells. Activation of these cells orchestrates the innate immune response and initiates liver inflammation in response to the danger signal from pathogens or injured cells and tissues. The cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway is a crucial signaling cascade of the innate immune system activated by cytosol DNA. Recognizing DNA as an immune-stimulatory molecule is an evolutionarily preserved mechanism in initiating rapid innate immune responses against microbial pathogens. The cGAS is a cytosolic DNA sensor eliciting robust immunity via the production of cyclic GMP-AMPs that bind and activate STING. Although the cGAS-STING pathway has been previously considered to have essential roles in innate immunity and host defense, recent advances have extended the role of the cGAS-STING pathway to liver diseases. Emerging evidence indicates that overactivation of cGAS-STING may contribute to the development of liver disorders, implying that the cGAS-STING pathway is a promising therapeutic target. Here, we review and discuss the role of the cGAS-STING DNA-sensing signaling pathway in a variety of liver diseases, including viral hepatitis, nonalcoholic fatty liver disease (NAFLD), alcoholic liver disease (ALD), primary hepatocellular cancer (HCC), and hepatic ischemia-reperfusion injury (IRI), with highlights on currently available therapeutic options.

Cells ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 837 ◽  
Author(s):  
Xiaowen Ma ◽  
Tara McKeen ◽  
Jianhua Zhang ◽  
Wen-Xing Ding

The mitochondrion is an organelle that plays a vital role in the regulation of hepatic cellular redox, lipid metabolism, and cell death. Mitochondrial dysfunction is associated with both acute and chronic liver diseases with emerging evidence indicating that mitophagy, a selective form of autophagy for damaged/excessive mitochondria, plays a key role in the liver’s physiology and pathophysiology. This review will focus on mitochondrial dynamics, mitophagy regulation, and their roles in various liver diseases (alcoholic liver disease, non-alcoholic fatty liver disease, drug-induced liver injury, hepatic ischemia-reperfusion injury, viral hepatitis, and cancer) with the hope that a better understanding of the molecular events and signaling pathways in mitophagy regulation will help identify promising targets for the future treatment of liver diseases.


MicroRNA ◽  
2020 ◽  
Vol 09 ◽  
Author(s):  
Chrysanthos D. Christou ◽  
Georgios Tsoulfas

Introduction: Ischemia-reperfusion (I/R) injuries are caused by complex interrelated mechanisms and pathways. Regarding the liver, I/R injuries and their clinical manifestations are crucial for the surgical outcome. Despite its importance, there is no broadly accepted therapy either for the prevention or for the management of I/R injury. I/R injury of the liver can occur either during hepatic surgery (warm) or during the transplantation procedure (cold). MicroRNAs play a pivotal role in the mechanism of I/R injury, as they regulate the expression of the cellular participants and humoral factors associated with I/R injury. Objective: In this review, we highlight the microRNAs that are involved in the I/R injury of the liver, and the molecular pathways that they regulate. In addition, we discuss the potential role of circulating microRNAs as biomarkers and their role as pharmacological targets in the prevention, diagnosis and treatment of I/R injuries. Method: We conducted a comprehensive review of the PubMed bibliographic database regarding microRNAs and I/R injuries of the liver. Results: In diagnostics, microRNA panels could replace invasive diagnostic procedures, relieving patients of the associated complications. In therapeutics, microRNA agomirs, antagomirs and other drugs can be used to shift the balance between proapoptotic and survival pathways, to alleviate the liver damage caused by I/R. In transplantation procedures, microRNA profiling could decrease the incidence of early graft dysfunction, especially regarding marginal grafts. Conclusion: Although microRNAs seem a very promising clinical tool in the management of I/R injuries, further research is required, until microRNAs become a novel tool in the diagnosis and monitoring of an I/R injury of the liver.


2005 ◽  
Vol 124 (1) ◽  
pp. 59-66 ◽  
Author(s):  
Taiji Watanabe ◽  
Sunao Kubota ◽  
Masaki Nagaya ◽  
Shoichi Ozaki ◽  
Hiroko Nagafuchi ◽  
...  

2006 ◽  
Vol 12 (23) ◽  
pp. 2953-2967 ◽  
Author(s):  
M. Habib ◽  
H. F. Hodgson ◽  
B. Davidson

Medicina ◽  
2019 ◽  
Vol 55 (6) ◽  
pp. 296 ◽  
Author(s):  
Pascale ◽  
Peitta ◽  
Simile ◽  
Feo

Several researchers have analyzed the alterations of the methionine cycle associated with liver disease to clarify the pathogenesis of human hepatocellular carcinoma (HCC) and improve the preventive and the therapeutic approaches to this tumor. Different alterations of the methionine cycle leading to a decrease of S-adenosylmethionine (SAM) occur in hepatitis, liver steatosis, liver cirrhosis, and HCC. The reproduction of these changes in MAT1A-KO mice, prone to develop hepatitis and HCC, demonstrates the pathogenetic role of MAT1A gene under-regulation associated with up-regulation of the MAT2A gene (MAT1A:MAT2A switch), encoding the SAM synthesizing enzymes, methyladenosyltransferase I/III (MATI/III) and methyladenosyltransferase II (MATII), respectively. This leads to a rise of MATII, inhibited by the reaction product, with a consequent decrease of SAM synthesis. Attempts to increase the SAM pool by injecting exogenous SAM have beneficial effects in experimental alcoholic and non-alcoholic steatohepatitis and hepatocarcinogenesis. Mechanisms involved in hepatocarcinogenesis inhibition by SAM include: (1) antioxidative effects due to inhibition of nitric oxide (NO•) production, a rise in reduced glutathione (GSH) synthesis, stabilization of the DNA repair protein Apurinic/Apyrimidinic Endonuclease 1 (APEX1); (2) inhibition of c-myc, H-ras, and K-ras expression, prevention of NF-kB activation, and induction of overexpression of the oncosuppressor PP2A gene; (3) an increase in expression of the ERK inhibitor DUSP1; (4) inhibition of PI3K/AKT expression and down-regulation of C/EBPα and UCA1 gene transcripts; (5) blocking LKB1/AMPK activation; (6) DNA and protein methylation. Different clinical trials have documented curative effects of SAM in alcoholic liver disease. Furthermore, SAM enhances the IFN-α antiviral activity and protects against hepatic ischemia-reperfusion injury during hepatectomy in HCC patients with chronic hepatitis B virus (HBV) infection. However, although SAM prevents experimental tumors, it is not curative against already established experimental and human HCCs. The recent observation that the inhibition of MAT2A and MAT2B expression by miRNAs leads to a rise of endogenous SAM and strong inhibition of cancer cell growth could open new perspectives to the treatment of HCC.


2014 ◽  
Vol 46 (7) ◽  
pp. 503-511 ◽  
Author(s):  
Yue Li ◽  
Yang Yang ◽  
Yingtong Feng ◽  
Juanjuan Yan ◽  
Chongxi Fan ◽  
...  

2018 ◽  
Vol 38 (5) ◽  
Author(s):  
Di Liu ◽  
Xin Jin ◽  
Chunqi Zhang ◽  
You Shang

Purpose: This article aimed to study the role of sevoflurane pre-conditioning in hepatic ischemia–reperfusion and its potential mechanism. Methods: Rat liver ischemia–reperfusion model was constructed. Serum TNF-α, IL-1β, IL-10, and IL-6 concentrations were detected by ELISA. Malondialdehyde (MDA), superoxide dismutase (SOD), and nitric oxide (NO) in liver homogenate were determined. Hematoxylin–Eosin (HE) staining, Tunel, and immunohistochemistry were performed. Ischemia–reperfusion hepatocyte model was established. Cells transfection was conducted. Apoptosis was observed by flow cytometry. Quantitative real-time PCR (qRT-PCR) and Western blotting analysis were used. Results: Compared with I/R group, liver damage degree, liver cell apoptosis, and glucose regulatory protein 78 (Grp78) expression was obviously reduced in rats of SEV group. TNF-α, IL-1β, and IL-6 concentrations were also significantly increased (P<0.01). MDA and NO concentrations were dramatically lower (P<0.01) and SOD concentration was significantly higher (P<0.01). Apoptosis rate, Grp78, PERK, eIF2α, and p-c-JNK/JNK expression was also significantly decreased (P<0.01). Sevoflurane significantly reduced apoptosis and expression of PERK, eIF2α, p-c-JNK/JNK by inhibiting the expression of Grp78 (P<0.01). Conclusion: Sevoflurane relieves hepatic ischemia–reperfusion injury by inhibiting the expression of Grp78.


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