Related Experiment Video
Updated: Mar 10, 2026
Improved Rodent Model of Myocardial Ischemia and Reperfusion Injury
Published on: March 7, 2022
Calpain inhibition modulates glycogen synthase kinase 3β pathways in ischemic myocardium: A proteomic and mechanistic
Brittany A Potz1, Ashraf A Sabe1, Nassrene Y Elmadhun1
1Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI.
Background:
Calpain inhibition has an enhancing effect on myocardial perfusion and improves myocardial density by inhibiting glycogen synthase kinase 3β (GSK-3β) and up-regulating downstream signaling pathways, including the insulin/PI3K and WNT/β-catenin pathways, in a pig model of chronic myocardial ischemia in the setting of metabolic syndrome.
Methods:
Pigs were fed a high-fat diet for 4 weeks, then underwent placement of an ameroid constrictor to the left circumflex artery. Three weeks later, the animals received no drug (high-cholesterol controls [HCC]), a high-dose calpain inhibitor (HCI), a low-dose calpain inhibitor (LCI), or a GSK-3β inhibitor (GSK-3βI). The diets and drug regimens were continued for 5 weeks and the myocardial tissue was harvested.
Results:
Calpain and GSK-3β inhibition caused an increase in myocardial perfusion ratios at rest and during pacing compared with controls. Pigs in the LCI and HCI groups had increased vessel density in the ischemic myocardium, and pigs in the GSK-3βI group had increased vessel density in the ischemic and nonischemic myocardium compared with the HCC group. Calpain inhibition modulates proteins involved in the insulin/PI3K and WNT/β-catenin pathways. Quantitative proteomics revealed that calpain and GSK-3β inhibition significantly modulated the expression of proteins enriched in cytoskeletal regulation, metabolism, respiration, and calcium-binding pathways.
Conclusions:
In the setting of metabolic syndrome, calpain or GSK-3β inhibition increases vessel density in both ischemic and nonischemic myocardial tissue. Calpain inhibition may exert these effects through the inhibition of GSK-3β and up-regulation of downstream signaling pathways, including the insulin/PI3K and WNT/β-catenin pathways.
Insights
Calpain or GSK-3β inhibition enhances myocardial perfusion and vessel density in pigs with metabolic syndrome. These effects may involve modulating key signaling pathways, improving heart health.
Area of Science:
- Cardiovascular Research
- Molecular Cardiology
- Metabolic Syndrome Research
Background:
- Metabolic syndrome complicates chronic myocardial ischemia.
- Calpain inhibition shows potential for improving cardiac function.
- GSK-3β is implicated in cardiovascular disease pathways.
Purpose of the Study:
- To investigate the effects of calpain and GSK-3β inhibition on myocardial perfusion and density.
- To explore the underlying molecular mechanisms, including insulin/PI3K and WNT/β-catenin pathways.
- To assess these effects in a pig model of chronic myocardial ischemia and metabolic syndrome.
Main Methods:
- A pig model was established using a high-fat diet and ameroid constrictor.
- Animals were treated with calpain inhibitors (high and low dose) or a GSK-3β inhibitor.
- Myocardial tissue was analyzed for perfusion, vessel density, and protein expression via quantitative proteomics.
Main Results:
- Both calpain and GSK-3β inhibition increased myocardial perfusion at rest and during pacing.
- Vessel density increased in ischemic myocardium with calpain inhibition and in both ischemic and nonischemic myocardium with GSK-3β inhibition.
- Proteomic analysis revealed modulation of pathways involved in cytoskeletal regulation, metabolism, respiration, and calcium binding.
Conclusions:
- Calpain or GSK-3β inhibition improves myocardial vessel density in ischemic and nonischemic tissues within a metabolic syndrome context.
- Calpain inhibition may act by inhibiting GSK-3β and activating insulin/PI3K and WNT/β-catenin pathways.
- These findings suggest therapeutic potential for targeting calpain and GSK-3β in cardiovascular disease associated with metabolic syndrome.
