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A Hypoxia-Reoxygenation Injury Model in Self-Assembling Human Cardioids
Published on: March 17, 2026
[Calreticulin expression increases during delayed cardioprotection induced by hypoxic preconditioning]
Fei-Fei Xu1, Yan Fu, Feng-Ying Liu
1Department of Pathophysiology, Chinese People's Liberation Army General Hospital, Beijing 100853, China.
Sheng Li Xue Bao : [Acta Physiologica Sinica]
|December 19, 2006
Summary
Hypoxic preconditioning (HPC) enhances cardioprotection by altering calreticulin (CRT) expression, improving myocardial function and reducing infarct size. p38 MAPK signaling is involved in this protective mechanism.
Area of Science:
- Cardiovascular Physiology
- Molecular Cardiology
- Cellular Signaling
Context:
- Myocardial infarction (MI) remains a leading cause of mortality, necessitating strategies to mitigate ischemic injury.
- Hypoxic preconditioning (HPC) is a phenomenon that confers protection against subsequent severe ischemic insults.
- The role of calreticulin (CRT) and its regulatory pathways in HPC-induced cardioprotection requires further elucidation.
Purpose:
- To investigate the alteration of calreticulin (CRT) expression during delayed cardioprotection induced by hypoxic preconditioning (HPC).
- To explore the intracellular signal transduction mechanisms, specifically the involvement of p38 mitogen-activated protein kinase (MAPK) and stress-activated protein kinase (SAPK), underlying CRT modulation by HPC.
- To assess the functional impact of CRT alterations on myocardial protection in both in vivo and in vitro models of ischemia/reperfusion injury.
Summary:
- In vivo studies demonstrated that HPC significantly improved cardiac function (+dp/dt(max) and -dp/dt(max)), reduced infarct size and area at risk in Wistar rats post-MI.
- HPC dramatically altered CRT expression, with a significant increase observed 24 hours post-infarction, correlating positively with myocardial function and negatively with infarct size.
- In cultured cardiomyocytes, HPC attenuated hypoxia/reoxygenation (H/R)-induced injury, modulating CRT expression and showing a positive correlation with p38 MAPK activity and a negative correlation with SAPK activity.
Impact:
- Findings indicate that HPC confers significant cardioprotection against ischemia/reperfusion injury, mediated in part by dynamic changes in CRT expression.
- The study suggests that p38 MAPK signaling pathways are involved in the up-regulation of CRT induced by HPC, contributing to the protective effect.
- This research provides insights into the molecular mechanisms of HPC and highlights CRT as a potential therapeutic target for myocardial protection.
