Related Experiment Video
Updated: Jul 15, 2026
Improved Rodent Model of Myocardial Ischemia and Reperfusion Injury
Published on: March 7, 2022
Overexpression of histidine-rich Ca-binding protein protects against ischemia/reperfusion-induced cardiac injury
Xiaoyang Zhou1, Guo-Chang Fan, Xiaoping Ren
1Department of Pharmacology and Cell Biophysics, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0575, USA.
Insights
Increased cardiac histidine-rich Ca-binding protein (HRC) protects the heart from ischemia/reperfusion injury. Overexpression of HRC improves cardiac function recovery and reduces infarct size, offering a potential therapeutic target for heart attack recovery.
Area of Science:
- Cardiology
- Molecular Biology
- Biochemistry
Background:
- The histidine-rich Ca-binding protein (HRC) is a sarcoplasmic reticulum Ca-storage protein implicated in cardiac dysfunction.
- Previous studies indicated HRC inhibits Ca-transport, potentially impacting cardiac health.
- Myocardial ischemia/reperfusion (I/R) injury involves complex Ca-cycling disruptions.
Purpose of the Study:
- To investigate the role of HRC in myocardial I/R injury.
- To determine if cardiac-specific HRC overexpression affects cardiac function and survival post-I/R.
- To elucidate the molecular mechanisms underlying HRC's effect on I/R injury.
Main Methods:
- Utilized a transgenic mouse model with cardiac-specific HRC overexpression.
- Assessed cardiac contractile parameters using Langendorff perfusion before and after induced I/R injury.
- Analyzed infarct size, creatine kinase release, and apoptotic markers (DNA fragmentation, Bcl-2, caspases) in both ex vivo and in vivo models.
Main Results:
- Transgenic HRC hearts showed depressed baseline function but significantly better recovery of left ventricular developed pressure post-I/R compared to wild types.
- HRC overexpression led to smaller infarct sizes and reduced creatine kinase release.
- Apoptotic cell death was attenuated in transgenic hearts, with decreased DNA fragmentation and altered Bcl-2 and caspase expression.
Conclusions:
- Increased cardiac HRC expression confers protection against ischemia/reperfusion injury.
- HRC overexpression improves functional recovery and reduces myocardial infarction size.
- Modulating cardiac HRC levels represents a potential therapeutic strategy for I/R injury.
Objective:
The histidine-rich Ca-binding protein (HRC) is a Ca-storage protein in cardiac sarcoplasmic reticulum. Recent transgenic studies revealed that this protein inhibits the maximal rates of sarcoplasmic reticulum Ca-transport, leading to cardiac dysfunction. In view of the role of sarcoplasmic reticulum Ca-cycling in myocardial ischemia/reperfusion injury, we designed this study to gain further insight into the role of HRC during ischemia/reperfusion.
Methods And Results:
The transgenic mouse model with cardiac-specific overexpression of HRC was utilized and cardiac contractile parameters were assessed before and after ischemia/reperfusion injury by Langendorff perfusion. After a 20-min stabilization period, the hearts were subjected to 40 min of global ischemia, followed by 60 min of reperfusion. We found that although transgenic (TG) hearts showed depressed cardiac function (25%) compared to wild types (WTs) at baseline, they exhibited better recovery of left ventricular developed pressure (86.6+/-2.6% in TGs vs. 58.3+/-4.0% in WTs of pre-ischemic values, P<0.05) and higher rates of contraction and relaxation after ischemia/reperfusion than WTs. This improvement was accompanied by smaller infarcts (23.1+/-1.7% in TGs vs. 41.1+/-2.5% in WTs of infarct region-to-risk region ratio, P<0.05) and lower creatine kinase release. Notably, the extent of apoptotic cell death was significantly attenuated, as evidenced by decreased DNA fragmentation, upregulation of the antiapoptotic protein Bcl-2, and downregulation of the active caspases (3, 9 and 12) following ischemia/reperfusion in TG hearts, compared with WTs. Extension of these studies to an in vivo model of 30-min myocardial ischemia, via coronary artery occlusion, followed by 24-h reperfusion, showed that the infarct region-to-risk region ratio was 9+/-0.9% in TGs, compared with 20.4+/-2.9% in WTs (P<0.05).
Conclusions:
Our findings suggest that increased cardiac HRC expression protects against ischemia/reperfusion injury in the heart, resulting in improved recovery of function and reduced infarction.
