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Updated: Jun 27, 2026
Improved Rodent Model of Myocardial Ischemia and Reperfusion Injury
Published on: March 7, 2022
Inducible and cardiac specific PTEN inactivation protects ischemia/reperfusion injury
Hongmei Ruan1, Jian Li, Shuxun Ren
1Department of Anesthesiology, University of California, Los Angeles, Los Angeles, CA 90095-1735, USA. hmruan@ucla.edu
Abstract:
PTEN is a dual lipid and protein phosphatase that antagonizes PI3K as well as other signaling pathways and regulates cellular survival and growth. However, its potential role in cardiac ischemia/reperfusion injury remains unknown. We established a transgenic mouse model with inducible and cardiac specific deletion of Pten gene (Pten(CKO)) in adult heart via tamoxifen dependent Cre-loxP mediated DNA recombination. 3 weeks after tamoxifen induced PTEN inactivation, elevated PI3K activity was observed in the Pten(CKO) hearts as determined from downstream AKT signaling. No significant differences in cardiac function as well as chamber size were observed between Pten(CKO) and Control animals based on echocardiography. In response to 30 min ischemia followed by 120 min reperfusion in Langendorff preparations, Pten(CKO) hearts developed significantly better function recovery than Control animals. At 60 min post reperfusion, the recovery of LVDP reached 77.9% of pre-ischemia basal in Pten(CKO) hearts vs 44.2% of Control (p<0.01). Consistent with the observed functional improvement, TTC staining revealed a significant reduction in infarct size in Pten(CKO) hearts compared with Control (24.2% vs 39.7%, p<0.05). Pten(CKO) hearts had significantly fewer apoptosis positive cardiomyocytes after I/R injury as identified by TUNEL staining. Furthermore, ERK activity and BCL-2 expression were not affected at basal but became significantly higher after ischemia/reperfusion in Pten(CKO) hearts. These data indicate that PTEN may play a role in ischemia/reperfusion injury by inhibiting anti-apoptotic survival signals. Inhibiting PTEN may serve as a potential approach to exert cardiac protection against ischemia reperfusion injury.
Insights
Inhibiting PTEN (phosphatase and tensin homolog) in the heart improves recovery from ischemia/reperfusion injury. This suggests PTEN blockade as a potential strategy for cardiac protection against heart attack damage.
Area of Science:
- Cardiovascular Biology
- Molecular Cardiology
- Cellular Signaling
Background:
- PTEN (phosphatase and tensin homolog) is a key regulator of cell survival and growth, antagonizing PI3K signaling.
- The role of PTEN in cardiac ischemia/reperfusion (I/R) injury is not well understood.
- Understanding PTEN's function in the heart is crucial for developing new therapeutic strategies.
Purpose of the Study:
- To investigate the role of PTEN in cardiac ischemia/reperfusion injury.
- To determine if PTEN inactivation affects cardiac function and response to I/R.
- To explore the potential of PTEN inhibition as a cardioprotective approach.
Main Methods:
- Generated a cardiac-specific inducible Pten knockout (Pten(CKO)) mouse model using Cre-loxP technology.
- Assessed cardiac function via echocardiography and Langendorff preparations.
- Evaluated infarct size using TTC staining and apoptosis using TUNEL staining post-I/R.
Main Results:
- Cardiac-specific PTEN deletion led to elevated PI3K/AKT signaling but did not alter basal cardiac function.
- Pten(CKO) hearts exhibited significantly improved functional recovery and reduced infarct size after I/R injury compared to controls.
- Reduced cardiomyocyte apoptosis and increased ERK activity and BCL-2 expression were observed in Pten(CKO) hearts post-I/R.
Conclusions:
- PTEN plays a critical role in mediating cardiac ischemia/reperfusion injury by suppressing anti-apoptotic survival pathways.
- Inhibition of PTEN demonstrates significant cardioprotective effects against I/R injury.
- Targeting PTEN represents a promising therapeutic strategy for preventing heart damage during ischemic events.
