Myocardial insufficiency is related to reduced subunit 4 content of cytochrome c oxidase.

ABSTRACT: BACKGROUND:Treatment of heart failure remains one of the most challenging task for intensive care medicine, cardiology and cardiac surgery. New options and better indicators are always required. Understanding the basic mechanisms underlying heart failure promote the development of adjusted therapy e.g. assist devices and monitoring of recovery. If cardiac failure is related to compromised cellular respiration of the heart, remains unclear. Myocardial respiration depends on Cytochrome c- Oxidase (CytOx) activity representing the rate limiting step for the mitochondrial respiratory chain. The enzymatic activity as well as mRNA expression of enzyme's mitochondrial encoded catalytic subunit 2, nuclear encoded regulatory subunit 4 and protein contents were studied in biopsies of cardiac patients suffering from myocardial insufficiency and dilated cardiomyopathy (DCM). METHODS:Fifty-four patients were enrolled in the study and underwent coronary angiography. Thirty male patients (mean age: 45 +/-?15 yrs.) had a reduced ejection fraction (EF) 35?±?12% below 45% and a left ventricular end diastolic diameter (LVEDD) of 71?±?10 mm bigger than 56 mm. They were diagnosed as having idiopathic dilated cardiomyopathy (DCM) without coronary heart disease and NYHA-class 3 and 4. Additionally, 24 male patients (mean age: 52 +/-?11 yrs.) after exclusion of secondary cardiomyopathies, coronary artery or valve disease, served as control (EF: 68?±?7, LVEDD: 51?±?7 mm). Total RNA was extracted from two biopsies of each person. Real-time PCR analysis was performed with specific primers followed by a melt curve analysis. Corresponding protein expression in the tissue was studied with immune-histochemistry while enzymatic activity was evaluated by spectroscopy. RESULTS:Gene and protein expression analysis of patients showed a significant decrease of subunit 4 (1.1 vs. 0.6, p?

SUBMITTER: Vogt S 

PROVIDER: S-EPMC6142347 | biostudies-literature | 2018 Sep

REPOSITORIES: biostudies-literature