CaMKIIδ Mediates Myocardial Ischemia/Reperfusion Injury Through NF-κB
Published Date:Feb 06 2013
Source:Circ Res. 112(6):935-944.
Ca2+/calmodulin-dependent Protein Kinase II
Calcium-Calmodulin-Dependent Protein Kinase Type 2
Gene Expression Profiling
I-kappa B Proteins
Ischemic Heart Disease
Myocardial Reperfusion Injury
Nuclear Factor Kappa B
Recovery Of Function
Transcription Factor RelA
Funding:1U54HK08460-01/HK/PHITPO CDC HHS/United States
8UL1TR000100-03/TR/NCATS NIH HHS/United States
HL080101/HL/NHLBI NIH HHS/United States
P01 HL080101/HL/NHLBI NIH HHS/United States
P01HL098053/HL/NHLBI NIH HHS/United States
T32 GM007752/GM/NIGMS NIH HHS/United States
Ca2+/calmodulin-dependent protein kinase II (CaMKII) has been implicated as a maladaptive mediator of cardiac ischemic injury. We hypothesized that the inflammatory response associated with in vivo ischemia/reperfusion (I/R) is initiated through CaMKII signaling.
To assess the contribution of CaMKIIδ to the development of inflammation, infarct and ventricular dysfunction following in vivo I/R and define early cardiomyocyte-autonomous events regulated by CaMKIIδ using cardiac-specific knockout (KO) mice.
Methods and Results
Wild-type (WT) and CaMKIIδ KO mice were subjected to in vivo I/R by occlusion of the left anterior descending (LAD) artery for 1-hr followed by reperfusion for various times. CaMKIIδ deletion protected the heart against I/R damage as evidenced by decreased infarct size, attenuated apoptosis and improved functional recovery. CaMKIIδ deletion also attenuated I/R induced inflammation and upregulation of NF-κB target genes. Further studies demonstrated that I/R rapidly increases CaMKII activity, leading to NF-κB activation within minutes of reperfusion. Experiments using cyclosporine A and cardiac-specific CaMKIIδ knockout mice indicate that NF-κB activation is initiated independent of necrosis and within cardiomyocytes. Expression of activated CaMKII in cardiomyocytes lead to I kappa B kinase (IKK) phosphorylation and concomitant increases in nuclear p65. Experiments using an IKK inhibitor support the conclusion that this is a proximal site of CaMKII-mediated NF-κB activation.
This is the first study demonstrating that CaMKIIδ mediates NF-κB activation in cardiomyocytes following in vivo I/R and suggests that CaMKIIδ serves to trigger, as well as to sustain subsequent changes in inflammatory gene expression that contribute to myocardial I/R damage.
application/pdf text/plain image/gif image/jpeg image/gif image/jpeg image/gif image/jpeg image/gif image/jpeg image/gif image/jpeg image/gif image/jpeg image/gif image/jpeg
You May Also Like: