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Updated: Feb 13, 2026
Murine Model of Intestinal Ischemia-reperfusion Injury
Published on: May 11, 2016
Oxidative cross-linking of proteins to DNA following ischemia-reperfusion injury
Arnold Groehler1, Stefan Kren2, Qinglu Li2
1Department of Medicinal Chemistry, University of Minnesota, 8-101 Weaver Densford Hall, 308 Harvard Street SE, Minneapolis, MN 55455, USA.
Insights
Reperfusion therapy after heart attack can cause damage due to reactive oxygen species (ROS). This study shows ROS create DNA-protein cross-links (DPCs) in heart cells, contributing to injury and cell death.
Area of Science:
- Cardiovascular Biology
- Molecular Medicine
- Biochemistry
Background:
- Myocardial infarction (MI) treatments restore blood flow but can cause reperfusion injury.
- Reactive oxygen species (ROS) influx during reperfusion is implicated in this damage.
- The precise molecular mechanisms underlying reperfusion injury remain incompletely understood.
Purpose of the Study:
- To investigate the molecular mechanisms of ischemia/reperfusion (I/R) injury in cardiomyocytes.
- To identify specific molecular adducts formed during I/R injury.
- To elucidate the role of DNA-protein cross-links (DPCs) in I/R-induced cardiac damage.
Main Methods:
- Utilized a rat model of myocardial infarction (MI) induced by left anterior descending artery ligation and reperfusion.
- Employed mass spectrometry to identify and characterize DNA-protein cross-links (DPCs) formed in cardiomyocytes.
- Conducted quantitative proteomics to identify proteins involved in DPC formation and global proteome alterations.
Main Results:
- Demonstrated the formation of toxic DNA-protein cross-links (DPCs), specifically thymidine-tyrosine (dT-Tyr) conjugates, in cardiomyocytes following I/R injury.
- Identified nearly 90 proteins involved in hydroxyl radical-induced DPC formation, including ROS scavengers and apoptosis regulators.
- Observed increased expression of mitochondrial proteins and sarcomere breakdown biomarkers, with less pronounced global proteome changes.
Conclusions:
- Ischemia/reperfusion injury involves oxidative stress leading to the formation of DNA-protein cross-links (DPCs) in cardiomyocytes.
- These DPCs may contribute to reperfusion injury by disrupting gene expression and promoting cardiomyocyte death.
- Findings provide insights into the molecular pathology of reperfusion injury, suggesting DPCs as potential therapeutic targets.
Abstract:
Myocardial infarction (MI) is a life-threatening condition that can occur when blood flow to the heart is interrupted due to a blockage in one or more of the coronary vessels. Current treatments of MI rapidly restore blood flow to the affected myocardium using thrombolytic agents or angioplasty. Adverse effects including inflammation, tissue necrosis, and ventricular dysfunction are, however, not uncommon following reperfusion therapy. These conditions are thought to be caused by a sudden influx of reactive oxygen species (ROS) to the affected myocardium. We employed the model of left anterior descending artery ligation/reperfusion surgery in a rat model to show that ischemia/reperfusion injury is associated with the formation of toxic DNA-protein cross-links (DPCs) in cardiomyocytes. Mass spectrometry based experiments have revealed that these conjugates were formed by a free radical mechanism and involved thymidine residues of DNA and tyrosine side chains of proteins (dT-Tyr). Quantitative proteomics experiments have identified nearly 90 proteins participating in hydroxyl radical-induced DPC formation, including ROS scavengers, contractile proteins, and regulators of apoptosis. Global proteome changes were less pronounced and included increased expression of mitochondrial proteins required for aerobic respiration and biomarkers of sarcomere breakdown following ischemia/reperfusion injury. Overall, our results are consistent with a model where sudden return of oxygen to ischemic tissues induces oxidative stress, inflammation, and the formation of DNA-protein cross-links that may contribute to reperfusion injury by desregulating gene expression and inducing cardiomyocyte death.
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