scholarly journals N6-methyladenosine demethylase FTO impairs hepatic ischemia–reperfusion injury via inhibiting Drp1-mediated mitochondrial fragmentation

2021 ◽  
Vol 12 (5) ◽  
Author(s):  
Ying Dong Du ◽  
Wen Yuan Guo ◽  
Cong Hui Han ◽  
Ying Wang ◽  
Xiao Song Chen ◽  
...  
Keyword(s):  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Mitochondrial Fragmentation ◽  
Hepatic Ischemia ◽  
Adeno Associated Virus ◽  
Downstream Target ◽  
Hepatic Ischemia Reperfusion

AbstractDespite N6-methyladenosine (m6A) is functionally important in various biological processes, its role and the underlying regulatory mechanism in the liver remain largely unexplored. In the present study, we showed that fat mass and obesity-associated protein (FTO, an m6A demethylase) was involved in mitochondrial function during hepatic ischemia–reperfusion injury (HIRI). We found that the expression of m6A demethylase FTO was decreased during HIRI. In contrast, the level of m6A methylated RNA was enhanced. Adeno-associated virus-mediated liver-specific overexpression of FTO (AAV8-TBG-FTO) ameliorated the HIRI, repressed the elevated level of m6A methylated RNA, and alleviated liver oxidative stress and mitochondrial fragmentation in vivo and in vitro. Moreover, dynamin-related protein 1 (Drp1) was a downstream target of FTO in the progression of HIRI. FTO contributed to the hepatic protective effect via demethylating the mRNA of Drp1 and impairing the Drp1-mediated mitochondrial fragmentation. Collectively, our findings demonstrated the functional importance of FTO-dependent hepatic m6A methylation during HIRI and provided valuable insights into the therapeutic mechanisms of FTO.

scholarly journals MicroRNA-141-3p Attenuates Oxidative Stress-induced Hepatic Ischemia Reperfusion Injury via Keap1/Nrf2 Pathway

2021 ◽  
Author(s):  
Tingting Li ◽  
Qingsong Chen ◽  
Jiangwen Dai ◽  
Zuotian Huang ◽  
Yunhai Luo ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Liver Transplantation ◽  
Reperfusion Injury ◽  
Inflammatory Responses ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Hepatic Ischemia ◽  
Hepatic Ischemia Reperfusion

Abstract Hepatic ischemia reperfusion injury (IRI) is a major factor affecting the prognosis of liver transplantation through a series of severe cell death and inflammatory responses. MicroRNA-141-3p (miR-141-3p) has been reported to be associated with hepatic steatosis and other liver diseases. However, the potential role of miR-141-3p in hepatic IRI is currently unknown. In the present study, we found that miR-141-3p levels were negatively correlated with alanine aminotransferase (ALT)/aspartate aminotransferase (AST) in liver transplantation patients. The results demonstrated that miR-141-3p was decreased in mouse liver tissue after hepatic IRI in mice and in hepatocytes after hypoxia/reoxygenation (H/R). Overexpression of miR-141-3p directly decreased Kelch-like ECH-associated protein 1 (Keap1) levels and attenuated cell apoptosis in vivo and in vitro, while inhibition of miR-141-3p facilitated apoptosis. Further experiments revealed that overexpression of miR-141-3p also attenuated oxidative stress-induced damage in hepatocytes under H/R conditions. Taken together, our results indicate that miR-141-3p plays a major role in hepatic IRI through the Keap1 signaling pathway, and the present study suggests that miR-141-3p might have a protective effect on hepatic IRI to some extent.

Remifentanil Preconditioning Reduces Hepatic Ischemia–Reperfusion Injury in Rats via  Inducible Nitric Oxide Synthase Expression

2011 ◽  
Vol 114 (5) ◽  
pp. 1036-1047 ◽  
Author(s):  
Li-Qun Yang ◽  
Kun-Ming Tao ◽  
Yan-Tao Liu ◽  
Chi-Wai Cheung ◽  
Michael G. Irwin ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Methyl Ester ◽  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Hepatic Ischemia ◽  
Hepatic Ischemia Reperfusion ◽  
Inducible Nos

Background Opioid preconditioning against ischemia reperfusion injury has been well studied in myocardial and neuronal tissues. The objective of this study was to determine whether remifentanil could attenuate hepatic injury and to investigate the mechanisms. Methods A rat model of hepatic ischemia reperfusion injury and a hepatocyte hypoxia reoxygenation (HR) injury model were used, respectively, in two series of experiments. Remifentanil was administered before ischemia or hypoxia and the experiments were repeated with previous administration of naloxone, L-arginine and N-ω-nitro-L-arginine methyl ester, a nonselective opioid receptor antagonist, a nitric oxide donor, and nitric oxide synthase (NOS) inhibitor, respectively. Serum aminotransferase, cytokines, and hepatic lipid peroxidation were measured. Histopathology examination and apoptotic cell detection were assessed. For the in vitro study, cell viability, intracellular nitric oxide, apoptosis, and NOS expression were evaluated. Results Remifentanil and L-arginine pretreatment reduced concentrations of serum aminotransferases and cytokines, decreased the concentrations of hepatic malondialdehyde and myeloperoxidase activity, and increased superoxide dismutase, nitric oxide, and inducible NOS expression in vivo. Decreased histologic damage and apoptosis were also seen in these two groups. These changes were prevented by previous administration of N-ω-nitro-L-arginine methyl ester but not naloxone. There was an increase in inducible NOS protein expression but not endogenous NOS in remifentanil and L-arginine pretreated groups compared with control, naloxone, and N-ω-nitro-L-arginine methyl ester groups. Conclusion Pretreatment with remifentanil can attenuate liver injury both in vivo and in vitro. Inducible NOS but not opioid receptors partly mediate this effect by exhausting reactive oxygen species and attenuating the inflammatory response.

scholarly journals Effects of GIT-27NO, a NO-donating compound, on hepatic ischemia/reperfusion injury

2019 ◽  
Vol 33 ◽  
pp. 205873841986273 ◽  
Author(s):  
Katia Mangano ◽  
Raffaele Lanteri ◽  
Maria Sofia Basile ◽  
Noemi Bellavia ◽  
Rosalia Latino ◽  
...  
Keyword(s):  
Reperfusion Injury ◽  
Hepg2 Cells ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Dimethyl Fumarate ◽  
Positive Control ◽  
Hepatic Ischemia ◽  
Hepatic Ischemia Reperfusion

Hepatic ischemia/reperfusion injury (IRI) is a clinical condition that may lead to cellular injury and organ dysfunction that can be observed in different conditions, such as trauma, shock, liver resection, and transplantation. Moderate levels of nitric oxide (NO) produced by the endothelial isoform of the NO synthase protect against liver IRI. GIT-27NO is a NO-derivative of the toll-like receptor 4 antagonist VGX-1027 that has been shown to possess both antineoplastic and immunomodulatory properties in vitro and in vivo. In this study, we have investigated the effects of this compound in vitro, in a model of oxidative stress induced in HepG2 cells by hydrogen peroxide (H2O2), and in vivo, in a rat model of IRI of the liver. GIT-27NO significantly counteracted the toxic effects induced by the H2O2 on the HepG2 cells and in vivo, GIT-27NO reduced the transaminase levels and the histological liver injury by reducing necrotic areas with preservation of viable tissue. These effects were almost similar to that of the positive control drug dimethyl fumarate. These data suggest that the beneficial effect of GIT-27NO in the hepatic IRI can be secondary to anti-oxidative effects and hepatocyte necrosis reduction probably mediated by NO release.

Attenuation of hepatic ischemia-reperfusion injury through CD47 blockade in vivo

2012 ◽  
Vol 215 (3) ◽  
pp. S138
Author(s):  
Bernard John DuBray ◽  
Pam T. Manning ◽  
William A. Frazier ◽  
Kristen L. Gunter ◽  
Parvathi Balachandran ◽  
...  
Keyword(s):  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Hepatic Ischemia ◽  
Hepatic Ischemia Reperfusion

Novel In Vitro Model For Studying Hepatic Ischemia-Reperfusion Injury Using Liver Cubes

2011 ◽  
Vol 165 (2) ◽  
pp. 281-282
Author(s):  
B.J. DuBray ◽  
K.D. Conzen ◽  
G.A. Upadhya ◽  
P. Balachandran ◽  
J. Jia ◽  
...  
Keyword(s):  
Reperfusion Injury ◽  
In Vitro Model ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Hepatic Ischemia ◽  
Vitro Model ◽  
Hepatic Ischemia Reperfusion

scholarly journals Acidic Microenvironment Aggravates the Severity of Hepatic Ischemia/Reperfusion Injury by Modulating M1-Polarization Through Regulating PPAR-γ Signal

2021 ◽  
Vol 12 ◽  
Author(s):  
Wei Ding ◽  
Yunfei Duan ◽  
Zhen Qu ◽  
Jiawei Feng ◽  
Rongsheng Zhang ◽  
...  
Keyword(s):  
Liver Injury ◽  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Hepatic Ischemia ◽  
Acidic Microenvironment ◽  
Ppar Γ ◽  
M1 Polarization ◽  
Hepatic Ischemia Reperfusion

Hepatic injury induced by ischemia and reperfusion (HIRI) is a major clinical problem after liver resection or transplantation. The polarization of macrophages plays an important role in regulating the severity of hepatic ischemia/reperfusion injury. Recent evidence had indicated that the ischemia induces an acidic microenvironment by causing increased anaerobic glycolysis and accumulation of lactic acid. We hypothesize that the acidic microenvironment might cause the imbalance of intrahepatic immunity which aggravated HIRI. The hepatic ischemia/reperfusion injury model was established to investigate the effect of the acidic microenvironment to liver injury. Liposomes were used to deplete macrophages in vivo. Macrophages were cultured under low pH conditions to analyze the polarization of macrophages in vitro. Activation of the PPAR-γ signal was determined by Western blot. PPAR-γ agonist GW1929 was administrated to functionally test the role of PPAR-γ in regulating macrophage-mediated effects in the acidic microenvironment during HIRI. We demonstrate that acidic microenvironment aggravated HIRI while NaHCO3 reduced liver injury through neutralizing the acid, besides, liposome abolished the protective ability of NaHCO3 through depleting the macrophages. In vivo and vitro experiment showed that acidic microenvironment markedly promoted M1 polarization but inhibited M2 polarization of macrophage. Furthermore, the mechanistic study proved that the PPAR-γ signal was suppressed during the polarization of macrophages under pH = 6.5 culture media. The addition of PPAR-γ agonist GW1929 inhibited M1 polarization under acidic environment and reduced HIRI. Our results indicate that acidic microenvironment is a key regulator in HIRI which promoted M1 polarization of macrophages through regulating PPAR-γ. Conversely, PPAR-γ activation reduced liver injury, which provides a novel therapeutic concept to prevent HIRI.

scholarly journals Renalase as a Novel Biomarker for Evaluating the Severity of Hepatic Ischemia-Reperfusion Injury

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Huili Li ◽  
Jianrong Guo ◽  
Hongli Liu ◽  
Yanfeng Niu ◽  
Lixia Wang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Mouse Models ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Dependent Manner ◽  
Hepatic Ischemia ◽  
Hepatic Ischemia Reperfusion ◽  
R Process

Hepatic ischemia-reperfusion (I/R) injury is a serious complication in clinical practice. However, no efficient biomarkers are available for the evaluation of the severity of I/R injury. Recently, renalase has been reported to be implicated in the I/R injury of various organs. This protein is secreted into the blood in response to increased oxidative stress. To investigate the responsiveness of renalase to oxidative stress, we examined the changes of renalase in cell and mouse models. We observed a significant increase of renalase expression in HepG2 cells in a time- and dose-dependent manner when treated with H2O2. Renalase expression also increased significantly in liver tissues that underwent the hepatic I/R process. The increased renalase levels could be efficiently suppressed by antioxidantsin vitroandin vivo. Furthermore, serum renalase levels were significantly increased in the mouse models and also efficiently suppressed by antioxidants treatment. The variation trends are consistent between renalase and liver enzymes in the mouse models. In conclusion, renalase is highly sensitive and responsive to oxidative stressin vitroandin vivo. Moreover, renalase can be detected in the blood. These properties make renalase a highly promising biomarker for the evaluation of the severity of hepatic I/R injury.

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