Radiation Treatment Persistently Alters Heart Cell Function to Produce Benefits in Heart Failure Patients

This paper is interesting as a first step on the way to further research into compensatory therapies that can reduce the cardiac muscle dysfunction of heart failure. One-time radiation therapy appears to persistently change cardiomyocyte behavior via altered epigenetic regulation of notch signaling, leading to modestly improved heart tissue function. Perhaps this should be taken as supportive of efforts to more directly target this regulatory pathway in the aging heart via other means. Cardiac radiotherapy (RT) may be effective in treating heart failure (HF) patients with refractory ventricular tachycardia (VT). The previously proposed mechanism of radiation-induced fibrosis does not explain the rapidity and magnitude with which VT reduction occurs clinically. Here, we demonstrate in hearts from RT patients that radiation does not achieve transmural fibrosis within the timeframe of VT reduction. Electrophysiologic assessment of irradiated murine hearts reveals a persistent supraphysiologic electrical phenotype, mediated by increases in NaV1.5 and Cx43. By sequencing and transgenic approaches, we identify Notch signaling as a mechanistic contributor to NaV1.5 upregulation after RT. Our study presents findings to suggest that radiation therapy, successfully used in patients with refractory VT, may increase levels of the cardiac sodium channel and improve conduction. Indeed, explanted cardiac specimens obtained from a treated patient with refractory VT revealed t...
Source: Fight Aging! - Category: Research Authors: Tags: Daily News Source Type: blogs