KCNQ1 autoantibodies: Another way to regulate IKs

摘要

A subset of patients with dilated cardiomyopathy (DCM) have been shown to carry increased levels of autoantibodies against P-adrenoceptors, muscarinic receptors, Na~+-K~+-ATPase, or troponin I. There is increasing evidence thatthese autoantibodies can have important electro-physiological consequences and may contribute to the arrhythmogenic risk of DCM patients. In this edition of Cardiovascular Research, Li et al. identify another potential electrophysiological target of autoantibodies by showingthat a subset of patients with DCM has elevated autoantibodies against the extracellular pore region of KCNQ1,the alpha-subunitofthe slowly activating delayed rectifier K~+ current (I_(ks)). Anti-KCNQ1 autoantibodies, present in ~6% of DCM patients, increased I_(ks) in human embryonic kidney cells, and were associated with shortened QT intervals in seropositive patients. This interesting study adds important new insights to our understanding of the regulation and potential dysfunction of I_(ks).