Related Experiment Video
Updated: Jun 9, 2025
Enhancing the Engraftment of Human Induced Pluripotent Stem Cell-derived Cardiomyocytes via a Transient Inhibition of Rho Kinase Activity
Published on: July 10, 2019
CHK1 attenuates cardiac dysfunction via suppressing SIRT1-ubiquitination
Tong-Tong Yang1, Liu-Hua Zhou1, Ling-Feng Gu1
1Department of Cardiology, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China.
Background:
Mitochondrial dysfunction is linked to myocardial ischemia-reperfusion (I/R) injury. Checkpoint kinase 1 (CHK1) could facilitate cardiomyocyte proliferation, however, its role on mitochondrial function in I/R injury remains unknown.
Methods:
To investigate the role of CHK1 on mitochondrial function following I/R injury, cardiomyocyte-specific knockout/overexpression mouse models were generated. Adult mouse cardiomyocytes (AMCMs) were isolated for in vitro study. Mass spectrometry-proteomics analysis and protein co-immunoprecipitation assays were conducted to dissect the molecular mechanism.
Results:
CHK1 was downregulated in myocardium post I/R and AMCMs post oxygen-glucose deprivation/re‑oxygenation (OGD/R). In vivo, CHK1 overexpression protected against I/R induced cardiac dysfunction, while heterogenous CHK1 knockout exacerbated cardiomyopathy. In vitro, CHK1 inhibited OGD/R-induced cardiomyocyte apoptosis and bolstered cardiomyocyte survival. Mechanistically, CHK1 attenuated oxidative stress and preserved mitochondrial metabolism in cardiomyocytes under I/R. Moreover, disrupted mitochondrial homeostasis in I/R myocardium was restored by CHK1 through the promotion of mitochondrial biogenesis and mitophagy. Through mass spectrometry analysis following co-immunoprecipitation, SIRT1 was identified as a direct target of CHK1. The 266-390 domain of CHK1 interacted with the 160-583 domain of SIRT1. Importantly, CHK1 phosphorylated SIRT1 at Thr530 residue, thereby inhibiting SMURF2-mediated degradation of SIRT1. The role of CHK1 in maintaining mitochondrial dynamics control and myocardial protection is abolished by SIRT1 inhibition, while inactivated mutation of SIRT1 Thr530 fails to reverse the impaired mitochondrial dynamics following CHK1 knockdown. CHK1 Δ390 amino acids (aa) mutant functioned similarly to full-length CHK1 in scavenging ROS and maintaining mitochondrial dynamics. Consistently, cardiac-specific SIRT1 knockdown attenuated the protective role of CHK1 in I/R injury.
Conclusions:
Our findings revealed that CHK1 mitigates I/R injury and restores mitochondrial dynamics in cardiomyocytes through a SIRT1-dependent mechanism.
Insights
Checkpoint kinase 1 (CHK1) protects the heart from ischemia-reperfusion (I/R) injury by preserving mitochondrial function. CHK1 achieves this through a SIRT1-dependent pathway, highlighting a novel therapeutic target for cardiac protection.
Area of Science:
- Cardiology
- Molecular Biology
- Mitochondrial Biology
Background:
- Mitochondrial dysfunction is a key factor in myocardial ischemia-reperfusion (I/R) injury.
- Checkpoint kinase 1 (CHK1) is known to promote cardiomyocyte proliferation, but its effect on mitochondrial function during I/R injury is unclear.
Purpose of the Study:
- To investigate the role of CHK1 in regulating mitochondrial function and cardiomyocyte survival following I/R injury.
- To elucidate the molecular mechanism by which CHK1 influences mitochondrial homeostasis and cardiac protection.
Main Methods:
- Generation of cardiomyocyte-specific CHK1 knockout and overexpression mouse models.
- Isolation of adult mouse cardiomyocytes for in vitro oxygen-glucose deprivation/re-oxygenation (OGD/R) studies.
- Utilized mass spectrometry-proteomics and co-immunoprecipitation assays to identify molecular targets and interactions.
Main Results:
- CHK1 expression was reduced in I/R injured myocardium and OGD/R stressed cardiomyocytes.
- CHK1 overexpression conferred protection against I/R injury, while CHK1 deficiency exacerbated cardiac dysfunction and apoptosis.
- CHK1 preserved mitochondrial metabolism, attenuated oxidative stress, and promoted mitochondrial biogenesis and mitophagy, identifying SIRT1 as a direct target phosphorylated by CHK1.
Conclusions:
- CHK1 mitigates myocardial I/R injury by enhancing mitochondrial function and promoting cardiomyocyte survival.
- The protective effects of CHK1 are mediated through a SIRT1-dependent mechanism, involving the inhibition of SIRT1 degradation.
- These findings establish CHK1 as a critical regulator of mitochondrial dynamics and a potential therapeutic target for I/R injury.
More Related Videos
05:58Mouse Electroacupuncture Fixation Device Fabrication for Electroacupuncture Pretreatment in Diabetic Cardiomyopathy Mouse Model
Published on: April 18, 2025
07:40Protection of H9c2 Myocardial Cells from Oxidative Stress by Crocetin via PINK1/Parkin Pathway-Mediated Mitophagy
Published on: May 26, 2023
Related Concept Videos
01:26Heart Failure Drugs: Inhibitors of Renin-Angiotensin System
01:17Pathophysiology of Heart Failure