Abstract
The ATP-sensitive potassium (KATP) channel is a critical metabolic sensor in skeletal muscle, yet its definitive molecular composition and functional roles remain contested. In this study, I conclusively demonstrate that the Kir6.2/SUR2 complex forms sarcolemmal KATP channel in mouse fast-twitch muscle. Genetic knock-out (KO) of Kir6.2 (Kcnj11−/−) or SUR2 (Abcc9−/−) resulted in a similar phenotype with increased fatigue resistance and a pathological rise in unstimulated resting tension at high-frequency stimulation. In contrast, SUR1 (Abcc8−/−) KO was ineffective. Furthermore, a CRISPR/Cas9 knock-in mouse model of a human SUR2A truncation variant (KCGV/KCGV) recapitulated the abnormal force accumulation, demonstrating that even loss-of-function of this subunit specifically disrupts electromechanical stability. Crucially, the KV7 channel agonist retigabine (20 µM) partially prevented the increase in unstimulated tension, suggesting a potential therapeutic approach. I also have developed a same-day, suspension-mode fluorescence ion-flux assay that provides a greater than two-fold enhancement in signal intensity and can be used as a stable base for future high-throughput therapeutic screening. This would eliminate uncertainties in muscle KATP channel biology and create a pipeline from mechanistic discovery to potential therapeutic approach.
Committee Chair
Colin G. Nichols
Committee Members
Nathaniel Huebsch, Gretchen Meyer
Degree
Master of Science (MS)
Author's Department
Biomedical Engineering
Document Type
Thesis
Date of Award
Fall 12-17-2025
Language
English (en)
Author's ORCID
https://orcid.org/0009-0004-0265-5067
Recommended Citation
Chen, Yuezhou, "Optimization of Research Pipeline to Characterize the Effects of ATP-sensitive Potassium Channels Mutations on Native Skeletal Muscle Fibers and Evaluate Potential Drug Therapy" (2025). McKelvey School of Engineering Theses & Dissertations. 1295.
https://openscholarship.wustl.edu/eng_etds/1295