Quantifying oxidative injury in the liver

1995 ◽  
Vol 268 (3) ◽  
pp. G471-G479 ◽  
Author(s):  
R. S. Poggetti ◽  
E. E. Moore ◽  
F. A. Moore ◽  
K. Koike ◽  
R. Tuder ◽  
...  

Oxidative injury is a mechanism common to both ischemia-reperfusion (IR) and leukocyte-mediated injury. Reperfused tissue beds and elaborated mediators can activate a cascade of intercellular and interorgan injuries that often precipitates multiple organ failure. Initiation of lung injury by gut IR is a case in point, but concomitant liver injury may have been overlooked because of the absence of comparably sensitive physiological markers. In this study, we explore the hypothesis that occurrence of portally derived oxidant-induced liver dysfunction may be detected with both sensitivity and specificity. We simulated pure oxidative injury to the liver and separated the contributions from secondary systemic oxidation. Both tissue and plasma indicators were evaluated, each reflecting aspects of oxidation, membrane integrity, and metabolic function. Tissue markers readily detect oxidative liver injury, but systemic 3-hydroxybutyrate (3-OHB) concentration and ketone body ratio (KBR) are the most sensitive. Comparison of 3-OHB concentrations against the corresponding KBR can be used to distinguish adjustments within a physiological range from the transition into injury.

Shock ◽  
2021 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Jaganathan Lakshmanan ◽  
Baochun Zhang ◽  
Kalen Wright ◽  
Amierreza T. Motameni ◽  
James L. Herbst ◽  
...  

2021 ◽  
Vol 12 ◽  
Author(s):  
Shih-En Tang ◽  
Wen-I Liao ◽  
Hsin-Ping Pao ◽  
Chin-Wang Hsu ◽  
Shu-Yu Wu ◽  
...  

Background: Poloxamer 188 (P188) possesses anti-inflammatory properties and can help to maintain plasma membrane function. P188 has been reported to exert beneficial effects in the treatment of various disorders. However, the effects of P188 in ischemia/reperfusion (IR)-induced acute lung injury have not been examined.Methods: We investigated the ability of P188 to attenuate IR-induced acute lung injury in rats and hypoxia/reoxygenation (HR) injury in murine epithelial cells. Isolated perfused rat lungs were exposed to 40 min ischemia followed by 60 min reperfusion to induce IR injury.Results: IR led to lung edema, increased pulmonary arterial pressure, promoted lung tissue inflammation and oxidative stress, and upregulated the levels of TNF-α, IL-6 and CINC-1, and increased Lactic dehydrogenase (LDH) activity in bronchoalveolar lavage fluid. IR also downregulated the levels of inhibitor of κB (IκB-α), upregulated nuclear factor (NF)-κB (NF-κB), and promoted apoptosis in lung tissues. P188 significantly suppressed all these effects. In vitro, P188 also exerted a similar effect in murine lung epithelial cells exposed to HR. Furthermore, P188 reduced the number of propidium iodide-positive cells, maintained cell membrane integrity, and enhanced cell membrane repair following HR.Conclusion: We conclude that P188 protects against lung IR injury by suppressing multiple signaling pathways and maintaining cell membrane integrity.


2020 ◽  
Vol 13 ◽  
Author(s):  
Milad Ashrafizadeh ◽  
Saeed Samarghandian ◽  
Kiavash Hushmandi ◽  
Amirhossein Zabolian ◽  
Md Shahinozzaman ◽  
...  

Background: Ischemia/reperfusion (I/R) injury is a serious pathologic event that occurs due to restriction in blood supply to an organ, followed by hypoxia. This condition leads to enhanced levels of pro-inflammatory cytokines such as IL-6 and TNF-, and stimulation of oxidative stress via enhancing reactive oxygen species (ROS) levels. Upon reperfusion, blood supply increases, but it deteriorates condition, and leads to generation of ROS, cell membrane disruption and finally, cell death. Plant derived-natural compounds are well-known due to their excellent antioxidant and anti-inflammatory activities. Quercetin is a flavonoid exclusively found in different vegetables, herbs, and fruits. This naturally occurring compound possesses different pharmacological activities making it appropriate option in disease therapy. Quercetin can also demonstrate therapeutic effects via affecting molecular pathways such as NF-B, PI3K/Akt and so on. Methods: In the present review, we demonstrate that quercetin administration is beneficial in ameliorating I/R injury via reducing ROS levels, inhibition of inflammation, and affecting molecular pathways such as TLR4/NF-B, MAPK and so on. Results and conclusion: Quercetin can improve cell membrane integrity via decreasing lipid peroxidation. Apoptotic cell death is inhibited by quercetin via down-regulation of Bax, and caspases, and upregulation of Bcl-2. Quercetin is able to modulate autophagy (inhibition/induction) in decreasing I/R injury. Nanoparticles have been applied for delivery of quercetin, enhancing its bioavailability and efficacy in alleviation of I/R injury. Noteworthy, clinical trials have also confirmed the capability of quercetin in reducing I/R injury.


2019 ◽  
Vol 17 (12) ◽  
pp. 1245-1256 ◽  
Author(s):  
Yuting Jin ◽  
Changyong Li ◽  
Dongwei Xu ◽  
Jianjun Zhu ◽  
Song Wei ◽  
...  

AbstractNotch signaling plays important roles in the regulation of immune cell functioning during the inflammatory response. Activation of the innate immune signaling receptor NLRP3 promotes inflammation in injured tissue. However, it remains unknown whether Jagged1 (JAG1)-mediated myeloid Notch1 signaling regulates NLRP3 function in acute liver injury. Here, we report that myeloid Notch1 signaling regulates the NLRP3-driven inflammatory response in ischemia/reperfusion (IR)-induced liver injury. In a mouse model of liver IR injury, Notch1-proficient (Notch1FL/FL) mice receiving recombinant JAG1 showed a reduction in IR-induced liver injury and increased Notch intracellular domain (NICD) and heat shock transcription factor 1 (HSF1) expression, whereas myeloid-specific Notch1 knockout (Notch1M-KO) aggravated hepatocellular damage even with concomitant JAG1 treatment. Compared to JAG1-treated Notch1FL/FL controls, Notch1M-KO mice showed diminished HSF1 and Snail activity but augmented NLRP3/caspase-1 activity in ischemic liver. The disruption of HSF1 reduced Snail activation and enhanced NLRP3 activation, while the adoptive transfer of HSF1-expressing macrophages to Notch1M-KO mice augmented Snail activation and mitigated IR-triggered liver inflammation. Moreover, the knockdown of Snail in JAG1-treated Notch1FL/FL livers worsened hepatocellular functioning, reduced TRX1 expression and increased TXNIP/NLRP3 expression. Ablation of myeloid Notch1 or Snail increased ASK1 activation and hepatocellular apoptosis, whereas the activation of Snail increased TRX1 expression and reduced TXNIP, NLRP3/caspase-1, and ROS production. Our findings demonstrated that JAG1-mediated myeloid Notch1 signaling promotes HSF1 and Snail activation, which in turn inhibits NLRP3 function and hepatocellular apoptosis leading to the alleviation of IR-induced liver injury. Hence, the Notch1/HSF1/Snail signaling axis represents a novel regulator of and a potential therapeutic target for liver inflammatory injury.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Christina D’Agrosa ◽  
Charles L. Cai ◽  
Faisal Siddiqui ◽  
Karen Deslouches ◽  
Stephen Wadowski ◽  
...  

Abstract Background Neonatal intermittent hypoxia (IH) results in oxidative distress in preterm infants with immature antioxidant systems, contributing to lung injury. Coenzyme Q10 (CoQ10) and fish oil protect against oxidative injury. We tested the hypothesis that CoQ10 is more effective than fish oil for prevention of IH-induced lung injury in neonatal rats. Methods Newborn rats were exposed to two clinically relevant IH paradigms at birth (P0): (1) 50% O2 with brief hypoxia (12% O2); or (2) room air (RA) with brief hypoxia (12% O2), until P14 during which they were supplemented with daily oral CoQ10, fish oil, or olive oil from P0 to P14. Pups were studied at P14 or placed in RA until P21 with no further treatment. Lungs were assessed for histopathology and morphometry; biomarkers of oxidative stress and lipid peroxidation; and antioxidants. Results Of the two neonatal IH paradigms 21%/12% O2 IH resulted in the most severe outcomes, evidenced by histopathology and morphometry. CoQ10 was effective for preserving lung architecture and reduction of IH-induced oxidative stress biomarkers. In contrast, fish oil resulted in significant adverse outcomes including oversimplified alveoli, hemorrhage, reduced secondary crest formation and thickened septae. This was associated with elevated oxidants and antioxidants activities. Conclusions Data suggest that higher FiO2 may be needed between IH episodes to curtail the damaging effects of IH, and to provide the lungs with necessary respite. The negative outcomes with fish oil supplementation suggest oxidative stress-induced lipid peroxidation.


2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Da Tang ◽  
Guang Fu ◽  
Wenbo Li ◽  
Ping Sun ◽  
Patricia A. Loughran ◽  
...  

Abstract Background Hepatic ischemia/reperfusion (I/R) injury can be a major complication following liver surgery contributing to post-operative liver dysfunction. Maresin 1 (MaR1), a pro-resolving lipid mediator, has been shown to suppress I/R injury. However, the mechanisms that account for the protective effects of MaR1 in I/R injury remain unknown. Methods WT (C57BL/6J) mice were subjected to partial hepatic warm ischemia for 60mins followed by reperfusion. Mice were treated with MaR1 (5-20 ng/mouse), Boc2 (Lipoxin A4 receptor antagonist), LY294002 (Akt inhibitor) or corresponding controls just prior to liver I/R or at the beginning of reperfusion. Blood and liver samples were collected at 6 h post-reperfusion. Serum aminotransferase, histopathologic changes, inflammatory cytokines, and oxidative stress were analyzed to evaluate liver injury. Signaling pathways were also investigated in vitro using primary mouse hepatocyte (HC) cultures to identify underlying mechanisms for MaR1 in liver I/R injury. Results MaR1 treatment significantly reduced ALT and AST levels, diminished necrotic areas, suppressed inflammatory responses, attenuated oxidative stress and decreased hepatocyte apoptosis in liver after I/R. Akt signaling was significantly increased in the MaR1-treated liver I/R group compared with controls. The protective effect of MaR1 was abrogated by pretreatment with Boc2, which together with MaR1-induced Akt activation. MaR1-mediated liver protection was reversed by inhibition of Akt. Conclusions MaR1 protects the liver against hepatic I/R injury via an ALXR/Akt signaling pathway. MaR1 may represent a novel therapeutic agent to mitigate the detrimental effects of I/R-induced liver injury.


Antioxidants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1243
Author(s):  
Eunus S. Ali ◽  
Grigori Y. Rychkov ◽  
Greg J. Barritt

TRPM2 channels admit Ca2+ and Na+ across the plasma membrane and release Ca2+ and Zn2+ from lysosomes. Channel activation is initiated by reactive oxygen species (ROS), leading to a subsequent increase in ADP-ribose and the binding of ADP-ribose to an allosteric site in the cytosolic NUDT9 homology domain. In many animal cell types, Ca2+ entry via TRPM2 channels mediates ROS-initiated cell injury and death. The aim of this review is to summarise the current knowledge of the roles of TRPM2 and Ca2+ in the initiation and progression of chronic liver diseases and acute liver injury. Studies to date provide evidence that TRPM2-mediated Ca2+ entry contributes to drug-induced liver toxicity, ischemia–reperfusion injury, and the progression of non-alcoholic fatty liver disease to cirrhosis, fibrosis, and hepatocellular carcinoma. Of particular current interest are the steps involved in the activation of TRPM2 in hepatocytes following an increase in ROS, the downstream pathways activated by the resultant increase in intracellular Ca2+, and the chronology of these events. An apparent contradiction exists between these roles of TRPM2 and the role identified for ROS-activated TRPM2 in heart muscle and in some other cell types in promoting Ca2+-activated mitochondrial ATP synthesis and cell survival. Inhibition of TRPM2 by curcumin and other “natural” compounds offers an attractive strategy for inhibiting ROS-induced liver cell injury. In conclusion, while it has been established that ROS-initiated activation of TRPM2 contributes to both acute and chronic liver injury, considerable further research is needed to elucidate the mechanisms involved, and the conditions under which pharmacological inhibition of TRPM2 can be an effective clinical strategy to reduce ROS-initiated liver injury.


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