High impact information on HCN2

• HCN expression under control conditions was HCN4 > HCN2 >> HCN1 [1].
• During vagal stimulation, HCN2-injected dogs showed rhythms originating from the left ventricle, the rate of which was significantly more rapid than in the controls [2].
• Hearts were then removed and injection sites visually identified and removed for microelectrode study of action potentials, patch clamp studies of pacemaker current, and/or immunohistochemical studies of HCN2 [2].
• BACKGROUND: We hypothesized that administration of the HCN2 gene to the left bundle-branch (LBB) system of intact dogs would provide pacemaker function in the physiological range of heart rates [2].
• BACKGROUND: We hypothesized that localized overexpression of the hyperpolarization-activated, cyclic nucleotide-gated (HCN2) pacemaker current isoform in canine left atrium (LA) would constitute a novel biological pacemaker [3].

Anatomical context of HCN2

• CHF significantly decreased sinus node HCN expression at both mRNA and protein levels (HCN2 by 78% and 82%; HCN4 by 42% and 77%, respectively) [1].

Analytical, diagnostic and therapeutic context of HCN2

• CONCLUSIONS: HCN2 overexpression provides an I(f)-based pacemaker sufficient to drive the heart when injected into a localized region of atrium, offering a promising gene therapy for pacemaker disease [3].

References