We have located links that may give you full text access.
Hyperglycemia regulates cardiac K + channels via O-GlcNAc-CaMKII and NOX2-ROS-PKC pathways.
Basic Research in Cardiology 2020 November 26
Chronic hyperglycemia and diabetes lead to impaired cardiac repolarization, K+ channel remodeling and increased arrhythmia risk. However, the exact signaling mechanism by which diabetic hyperglycemia regulates cardiac K+ channels remains elusive. Here, we show that acute hyperglycemia increases inward rectifier K+ current (IK1 ), but reduces the amplitude and inactivation recovery time of the transient outward K+ current (Ito ) in mouse, rat, and rabbit myocytes. These changes were all critically dependent on intracellular O-GlcNAcylation. Additionally, IK1 amplitude and Ito recovery effects (but not Ito amplitude) were prevented by the Ca2+ /calmodulin-dependent kinase II (CaMKII) inhibitor autocamtide-2-related inhibitory peptide, CaMKIIδ-knockout, and O-GlcNAc-resistant CaMKIIδ-S280A knock-in. Ito reduction was prevented by inhibition of protein kinase C (PKC) and NADPH oxidase 2 (NOX2)-derived reactive oxygen species (ROS). In mouse models of chronic diabetes (streptozotocin, db/db, and high-fat diet), heart failure, and CaMKIIδ overexpression, both Ito and IK1 were reduced in line with the downregulated K+ channel expression. However, IK1 downregulation in diabetes was markedly attenuated in CaMKIIδ-S280A. We conclude that acute hyperglycemia enhances IK1 and Ito recovery via CaMKIIδ-S280 O-GlcNAcylation, but reduces Ito amplitude via a NOX2-ROS-PKC pathway. Moreover, chronic hyperglycemia during diabetes and CaMKII activation downregulate K+ channel expression and function, which may further increase arrhythmia susceptibility.
Full text links
Related Resources
Trending Papers
Angiotensin Receptor Blocker-Neprilysin Inhibitor for Heart Failure with Reduced Ejection Fraction.Pharmacological Research : the Official Journal of the Italian Pharmacological Society 2024 May 12
Drug Therapy for Acute and Chronic Heart Failure with Preserved Ejection Fraction with Hypertension: A State-of-the-Art Review.American Journal of Cardiovascular Drugs : Drugs, Devices, and Other Interventions 2024 April 5
Guillain-Barré syndrome: History, pathogenesis, treatment, and future directions.European Journal of Neurology 2024 May 17
The Therapy and Management of Heart Failure with Preserved Ejection Fraction: New Insights on Treatment.Cardiac Failure Review 2024
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app
All material on this website is protected by copyright, Copyright © 1994-2024 by WebMD LLC.
This website also contains material copyrighted by 3rd parties.
By using this service, you agree to our terms of use and privacy policy.
Your Privacy Choices
You can now claim free CME credits for this literature searchClaim now
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app