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Updated: Aug 3, 2026
Post-Myocardial Infarction Heart Failure in Closed-chest Coronary Occlusion/Reperfusion Model in Göttingen Minipigs and Landrace Pigs
Published on: April 17, 2021
Targeting of CIP4-Calcineurin Signalosomes Improves Cardiac Structure and Function After Myocardial Infarction
Background:
Calcineurin in a pleiotropic signaling enzyme that promotes pathological cardiac remodeling but also cardioprotection in ischemia-reperfusion injury. In addition, calcineurin inhibitors are immunosuppressants. This pleiotropy has precluded the use of calcineurin inhibitors as treatments for heart failure. Cdc42-interacting protein 4 (CIP4/TRIP10) is an endosomal scaffold protein that organizes a calcium and calcineurin Aβ2 (CaNAβ2) signaling compartment activated by G-protein coupled receptors independently of contractile calcium. CIP4 binds CaNAβ2 via the CaNAβ-specific N-terminal polyproline (PP) domain. We previously showed that targeting of CIP4-CaNAβ2 signalosomes inhibited pathological cardiac hypertrophy and the development of heart failure induced by chronic pressure overload in mice. It is unknown whether CIP4-CaNAβ2 signalosomes contribute to cardioprotection and/or cardiac remodeling in ischemic heart disease.
Methods:
CIP4 conditional knock-out (CKO) mice were studied by echocardiography with strain analysis and histology following ischemia-reperfusion (I/R) injury and permanent left coronary artery (LCA) ligation to induce myocardial infarction. Wildtype C57BL/6NJ mice were transduced with adeno-associated virus (AAV) engineered for cardiomyocyte-specific expression of either a CaNAβ2 shRNA to inhibit CaNAβ2 expression, a VIVIT peptide to inhibit CaN-NFAT signaling, or a CaNAβ2 PP peptide to block CIP4-CaNAβ2 binding. AAV-transduced mice were studied by I/R injury. Additional mice were subjected to permanent LCA ligation and subsequently treated with AAV to test the effects of CaN inhibition in chronic ischemic cardiomyopathy. The effects of CaNAβ2 PP-GFP expression on primary T-cell activation were studied in vitro .
Results:
CIP4 CKO mice and mice expressing the PP anchoring disruptor peptide exhibited preserved cardiac function after I/R injury and decreased infarct size and preserved cardiac function 8 weeks after myocardial infarction by permanent LCA ligation. In contrast, cardiomyocyte-specific depletion of CaNAβ2 and VIVIT peptide expression worsened outcome after I/R injury and in chronic ischemic cardiomyopathy. In addition, in contrast to cardiomyocytes, PP-mediated CaNAβ anchoring inhibition had no effect on T-cell activation and cytokine expression in vitro .
Conclusions:
CIP4-CaNAβ2 signalosomes promote adverse cardiac remodeling and are not cardioprotective. Proof-of-concept is provided for the treatment of ischemic cardiomyopathy by a PP anchoring disruptor gene therapy. Targeting these complexes may be beneficial in cardiovascular diseases, including ischemic cardiomyopathy and acute myocardial infarction.
Clinical Perspective:
What is New?: Targeting CIP4, which is a scaffold protein for the phosphatase calcineurin, improves cardiac function in mice after acute myocardial infarction due to ischemia-reperfusion injury and in chronic ischemic cardiomyopathy.Gene therapy-based expression of a calcineurin Aβ-derived polyproline peptide, which can compete CIP4-calcineurin binding, is beneficial in acute and chronic myocardial infarction.What Are the Clinical Implications?: This study establishes CIP4 signalosomes as a new drug target for the treatment of ischemia-reperfusion injury and chronic pathological cardiac remodeling.This study provides proof-of-concept for a new gene therapy approach to treating acute myocardial infarction and chronic ischemic cardiomyopathy.
Insights
Targeting Cdc42-interacting protein 4 (CIP4) signalosomes improves cardiac function in mice with myocardial infarction and ischemic cardiomyopathy. Gene therapy using a calcineurin Aβ-derived peptide shows promise for treating these cardiovascular conditions.
Area of Science:
- Cardiovascular Research
- Molecular Cardiology
- Gene Therapy
Background:
- Calcineurin is a signaling enzyme with dual roles in cardiac remodeling and cardioprotection, complicating its therapeutic use.
- Cdc42-interacting protein 4 (CIP4) organizes calcineurin Aβ2 (CaNAβ2) signaling compartments, independent of contractile calcium.
- Previous studies indicated CIP4-CaNAβ2 signalosomes inhibit pathological cardiac hypertrophy.
Purpose of the Study:
- To investigate the role of CIP4-CaNAβ2 signalosomes in cardioprotection and cardiac remodeling following ischemic heart disease.
- To evaluate the therapeutic potential of targeting CIP4-CaNAβ2 interactions in mouse models of myocardial infarction and chronic ischemic cardiomyopathy.
Main Methods:
- Utilized CIP4 conditional knock-out (CKO) mice and adeno-associated virus (AAV)-mediated gene transfer in wildtype mice.
- Assessed cardiac function and infarct size using echocardiography, strain analysis, and histology after ischemia-reperfusion (I/R) injury and permanent left coronary artery (LCA) ligation.
- Investigated the effects of inhibiting CaNAβ2 expression, CaN-NFAT signaling (VIVIT peptide), or CIP4-CaNAβ2 binding (PP peptide) in cardiomyocytes and T-cells.
Main Results:
- CIP4 CKO mice and mice expressing the PP peptide showed preserved cardiac function and reduced infarct size after I/R injury and myocardial infarction.
- Cardiomyocyte-specific depletion of CaNAβ2 or VIVIT peptide worsened outcomes in I/R injury and chronic ischemic cardiomyopathy models.
- PP-mediated inhibition of CaNAβ anchoring did not affect T-cell activation or cytokine expression in vitro.
Conclusions:
- CIP4-CaNAβ2 signalosomes promote adverse cardiac remodeling and are not cardioprotective in ischemic heart disease.
- Targeting CIP4-CaNAβ2 complexes offers a potential therapeutic strategy for cardiovascular diseases, including ischemic cardiomyopathy and myocardial infarction.
- Gene therapy with a PP anchoring disruptor peptide provides proof-of-concept for treating acute and chronic ischemic heart conditions.
