Trolox and ascorbate: are they synergistic in protecting liver cells in vitro and in vivo?

1991 ◽  
Vol 69 (2-3) ◽  
pp. 198-201 ◽  
Author(s):  
L.-H. Zeng ◽  
Jun Wu ◽  
Doug Carey ◽  
T.-W. Wu
Keyword(s):  
Hydrogen Peroxide ◽  
Body Weight ◽  
Ischemia Reperfusion ◽  
Water Soluble ◽  
Cultured Hepatocytes ◽  
Hepatic Ischemia ◽  
Multilamellar Liposomes ◽  
Hepatic Ischemia Reperfusion

From in vitro studies involving multilamellar liposomes or other artificial systems, several groups of workers have deduced that Trolox (a water-soluble analogue of vitamin E) and ascorbate are synergistic antioxidants. Here, we demonstrate that while Trolox and ascorbate individually protect cultured hepatocytes against oxyradicals generated either with xanthine oxidase plus hypoxanthine or with hydrogen peroxide, the two antioxidants do not appear to be synergistic when used in equimolar combinations. Also, in a rat model of hepatic ischemia–reperfusion, we observed that infusion of Trolox or ascorbate (7.5–10 μmol/kg body weight) into the postischemic liver reduced the reperfusion injury by 76 or 67%, respectively. However, when both compounds were used together (each at the same dose as used separately), the organ salvage amounted to only 79%. Therefore, there is no evidence of synergism between Trolox and ascorbate in our in vitro and especially in vivo systems.Key words: synergism, vitamin C, Trolox, antioxidants.

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 Role of miR-148a in Mitigating Hepatic Ischemia-Reperfusion Injury by Repressing the TLR4 Signaling Pathway via Targeting CaMKIIα in Vivo and in Vitro

2018 ◽  
Vol 49 (5) ◽  
pp. 2060-2072 ◽  
Author(s):  
Daofeng Zheng ◽  
Zhongtang Li ◽  
Xufu Wei ◽  
Rui Liu ◽  
Ai Shen ◽  
...  
Keyword(s):  
Liver Dysfunction ◽  
Ischemia Reperfusion ◽  
Inflammatory Factors ◽  
Luciferase Reporter ◽  
Hepatic Ischemia ◽  
Tlr4 Signaling ◽  
Hepatic Ischemia Reperfusion

Background/Aims: Hepatic ischemia-reperfusion (I/R) injury, which is mainly induced by inflammation and unstable intracellular ions, is a major negative consequence of surgery that compromises hepatic function. However, the exact mechanisms of liver I/R injury have not been determined. Positive crosstalk with the Ca2+/CaMKII pathway is required for complete activation of the TLR4 pathway and inflammation. We previously found that miR-148a, which decreased in abundance with increasing reperfusion time, targeted and repressed the expression of CaMKIIα. In the present study, we examined the role of the miR-148a machinery in I/R-induced Ca2+/CaMKII and TLR4 signaling changes, inflammation, and liver dysfunction in vivo and in vitro. Methods: Liver function was evaluated by serum aminotransferase levels and hematoxylin-eosin (HE) staining. Inflammatory factors were detected by enzyme-linked immunosorbent assay. Gene and protein expression were assessed by RT-PCR and western blot. Small interfering RNA was used to silence target gene expression. HE staining and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling were used to measure hepatic tissue apoptosis. These assays were performed to identify factors upregulated in hepatic I/R injury and downregulated by miR-148a. Results: We manifested that expression of CaMKIIα and phosphorylation of TAK1 and IRF3 were elevated in hypoxia/reoxygenation (H/R)-treated primary Kupffer cells (KCs) and liver tissue of I/R-treated mice, but these effects were attenuated by treatment with miR-148a mimic and were accompanied by the alleviation of liver dysfunction and hepatocellular apoptosis. Luciferase reporter experiments showed that miR148a suppressed luciferase activity by almost 60%. Moreover, knockdown of CaMKIIα in H/R KCs led to significant deficiencies in p-TAK1, P-IRF3, IL-6, and TNF-α, which was consistent with the effects of miR-148a overexpression. Otherwise, the same trend of activation of TAK1 and IRF3 and inflammatory factors in vitro was observed in the siTAK1 + siIRF3 group compared with the siCaMKIIα group. Conclusion: Taken together, we conclude that miR-148a may mitigate hepatic I/R injury by ameliorating TLR4-mediated inflammation via targeting CaMKIIα in vitro and in vivo.

scholarly journals Aloin Preconditioning Attenuates Hepatic Ischemia/Reperfusion Injury via Inhibiting TLR4/MyD88/NF-κB Signal Pathway In Vivo and In Vitro

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Yichao Du ◽  
Baolin Qian ◽  
Lin Gao ◽  
Peng Tan ◽  
Hao Chen ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Inflammatory Response ◽  
Liver Tissue ◽  
Molecular Mechanisms ◽  
Ischemia Reperfusion ◽  
Primary Hepatocytes ◽  
Hepatic Ischemia ◽  
Hepatic Ischemia Reperfusion

Background. Aloin exerts considerable protective effects in various disease models, and its effect on hepatic ischemia-reperfusion (HIR) injury remains unknown. This research is aimed at conducting an in-depth investigation of the antioxidant, anti-inflammatory, and antiapoptosis effects of aloin in HIR injury and explain the underlying molecular mechanisms. Methods. In vivo, different concentrations of aloin were intraperitoneally injected 1 h before the establishment of the HIR model in male mice. The hepatic function, pathological status, oxidative stress, and inflammatory and apoptosis markers were measured. In vitro, aloin (AL, C21H22O9) or lipopolysaccharide (LPS) was added to a culture of mouse primary hepatocytes before it underwent hypoxia/reoxygenation (H/R), and the apoptosis in the mouse primary hepatocytes was analyzed. Results. We found that 20 mg/kg was the optimum concentration of aloin for mitigating I/R-induced liver tissue damage, characterized by decreased serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Aloin pretreatment substantially suppressed the generation of hepatic malondialdehyde (MDA), tumor necrosis factor alpha (TNF-α), and IL-6 and enhanced the hepatic superoxide dismutase (SOD) activities as well as glutathione (GSH) and IL-10 levels in the liver tissue of I/R mice; this indicated that aloin ameliorated I/R-induced liver damage by reducing the oxidative stress and inflammatory response. Moreover, aloin inhibited hepatocyte apoptosis and inflammatory response that was caused by the upregulated expression of Bcl-2, the downregulated expression of cleaved caspase3(C-caspase3), Bax, Toll-like receptor 4 (TLR4), FADD, MyD88, TRAF6, phosphorylated IKKα/β (p-IKKα/β), and phosphorylated nuclear factor κB p65 (p-NF-κB p65).

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 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.

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.

LncRNA Gm4419 induces cell apoptosis in hepatic ischemia–reperfusion injury via regulating the miR-455–SOX6 axis

2020 ◽  
Vol 98 (4) ◽  
pp. 474-483 ◽  
Author(s):  
Dongjian Ying ◽  
Xinhua Zhou ◽  
Yi Ruan ◽  
Luoluo Wang ◽  
Xiang Wu
Keyword(s):  
Cell Apoptosis ◽  
Ischemia Reperfusion Injury ◽  
Cell Model ◽  
Ischemia Reperfusion ◽  
Annexin V ◽  
Luciferase Reporter ◽  
Hepatic Ischemia ◽  
Hepatic Ischemia Reperfusion

Long non-coding RNA (lncRNA) is known to be involved in a variety of diseases. However, the role of Gm4419 in hepatic ischemia–reperfusion (I/R) injury remains unknown. To study this, we first established a rat model of hepatic I/R, and a BRL-3A cell model of hypoxia–reoxygenation (H/R) for in vivo and in vitro studies. Staining with hematoxylin and eosin and hepatic injury scores were used to evaluate the degree of hepatic I/R injury. Cell apoptosis was assessed via staining with Edu, and with annexin V–FITC–propidium iodide assays. The interactions between Gm4419 and miR-455, as well as miR-455 and SOX6 were evaluated via luciferase reporter activity assays and RNA immunoprecipitation assays. In vivo, we found that Gm4419 was up-regulated in the rats subjected to I/R. Moreover, knockdown of Gm4419 alleviated the I/R-induced liver damage in the rats. In vitro, knockdown of Gm4419 alleviated H/R-induced apoptosis in BRL-3A cells. Interestingly, we found that miR-455 is a target of Gm4419, and Gm4419 regulates the expression of miR-455 via sponging. Furthermore, SOX6 was proven to be the target of miR-455. Finally, rescue experiments confirmed that knockdown of Gm4419 inhibits apoptosis by regulating miR-455 and SOX6 in H/R-treated BRL-3A cells. Therefore, our findings show that the lncRNA Gm4419 accelerates hepatic I/R injury by targeting the miR-455–SOX6 axis, which suggests a novel therapeutic target for hepatic I/R injury.

scholarly journals PGC-1α Protects against Hepatic Ischemia Reperfusion Injury by Activating PPARα and PPARγ and Regulating ROS Production

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Chaoqun Wang ◽  
Zihao Li ◽  
Baolei Zhao ◽  
Yaohua Wu ◽  
Yao Fu ◽  
...  
Keyword(s):  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Peroxisome Proliferator ◽  
Hepatic Ischemia ◽  
Peroxisome Proliferator Activated Receptors ◽  
Hepatic Ischemia Reperfusion ◽  
Serum Aminotransferases

Peroxisome proliferator-activated receptors (PPARs) α and γ have been shown to be protective in hepatic ischemia/reperfusion (I/R) injury. However, the precise role of PPARγ coactivator-1α (PGC-1α), which can coactivate both of these receptors, in hepatic I/R injury, remains largely unknown. This study was designed to test our hypothesis that PGC-1α is protective during hepatic I/R injury in vitro and in vivo. Our results show that endogenous PGC-1α is basally expressed in normal livers and is moderately increased by I/R. Ectopic PGC-1α protects against hepatic I/R and hepatocyte anoxia/reoxygenation (A/R) injuries, whereas knockdown of endogenous PGC-1α aggravates such injuries, as evidenced by assessment of the levels of serum aminotransferases and inflammatory cytokines, necrosis, apoptosis, cell viability, and histological examination. The EMSA assay shows that the activation of PPARα and PPARγ is increased or decreased by the overexpression or knockdown of PGC-1α, respectively, during hepatic I/R and hepatocyte A/R injuries. In addition, the administration of specific antagonists of either PPARα (MK886) or PPARγ (GW9662) can effectively decrease the protective effect of PGC-1α against hepatic I/R and hepatocyte A/R injuries. We also demonstrate an important regulatory role of PGC-1α in reactive oxygen species (ROS) metabolism during hepatic I/R, which is correlated with the induction of ROS-detoxifying enzymes and is also dependent on the activations of PPARα and PPARγ. These data demonstrate that PGC-1α protects against hepatic I/R injury, mainly by regulating the activation of PPARα and PPARγ. Thus, PGC-1α may be a promising therapeutic target for the protection of the liver against I/R injury.

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