RT Journal Article
SR Electronic
T1 Regional Differences in the Ghrelin-Growth Hormone Secretagogue Receptor Signalling System in Human Heart Disease
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2020.07.13.201319
DO 10.1101/2020.07.13.201319
A1 Sullivan, Rebecca
A1 Randhawa, Varinder K
A1 Lalonde, Tyler
A1 Yu, Tina
A1 Kiaii, Bob
A1 Luyt, Leonard
A1 Wisenberg, Gerald
A1 Dhanvantari, Savita
YR 2020
UL http://biorxiv.org/content/early/2020/10/05/2020.07.13.201319.abstract
AB The hormone ghrelin and its receptor, the growth hormone secretagogue receptor (GHSR) are expressed in myocardium. GHSR binding activates signalling pathways coupled to cardiomyocyte survival and contractility. These properties have made the ghrelin-GHSR axis a candidate for a biomarker of cardiac function. The dynamics of ghrelin-GHSR are altered significantly in late stages of heart failure and cardiomyopathy, when left ventricular (LV) function is failing. We examined the relationship of GHSR with ghrelin in cardiac tissue from patients with valvular disease with no detectable changes in LV function. Biopsy samples from the LV and left atrium (LA) were obtained from 25 patients with valvular disease (of whom 13 also had coronary artery disease) and preserved LV ejection fraction, and compared control samples obtained via autopsy. Using quantitative confocal fluorescence microscopy, levels of GHSR were determined using a fluorescent peptide analog of ghrelin, Cy5-ghrelin(1-19); ghrelin, the heart failure marker natriuretic peptide type-b (BNP), and contractility marker sarcoplasmic reticulum ATPase pump (SERCA2a) were measured by immunofluorescence. A positive correlation between GHSR and ghrelin was apparent in only diseased tissue. Ghrelin and BNP significantly correlated in the LV and strongly co-localized to the same intracellular compartment in both diseased and control tissue. GHSR, ghrelin and BNP all strongly and significantly correlated with SERCA2a in the LV of diseased tissue only. Our results suggest that the dynamics of the myocardial ghrelin/GHSR axis is altered in cardiovascular disease in the absence of measurable changes in heart function, and may accompany a regional shift in endocrine programming.Competing Interest StatementThe authors have declared no competing interest.