Xu Lab
Research Overview
Arrhythmias remain a major health problem, causing at least 250,000 deaths annually in the United States. Dr. Xu's long term goal is to elucidate molecular signaling pathways involving the development of cardiac arrhythmias so that therapeutic targets for treatment and/or prevention can be identified. It has been shown that p90 ribosomal S6 kinase (p90RSK) activity is significantly increased in different types of cardiac diseases, in which QT-interval is prolonged, increasing the frequency of cardiac arrhythmia. In his lab, he has been exploiting a sophisticated combination of biochemical, electrophysiological and molecular techniques to define the molecular mechanism by which activation of p90RSK prolongs cardiac repolarization.
This mechanism would potentially predispose to arrhythmias via phosphorylating Kv4.3 alpha subunit, one main component of transient outward K+ current (Ito,f) channel and thus inhibiting this channel activity. Ongoing interests include studies focused on defining the functional roles of two delayed rectifier K+ currents, IKr and IKs modulation by p90RSK in the development of cardiac arrhythmias in diabetic cardiomyopathy and cardiac ischemia/reperfusion.
