GPx-1 isoenzyme - biomarker in the assessment of lipid oxidative risk, immunogenesis and arrhythmogenic potential
Authors: Bezna M C , Istratoaie O , Danoiu S , Bezna M , Toader D M , Mustafa R E , Donoiu I , Pisoschi C , Melinte P R 
Published: November 2023

Abstract

Introduction
Biomarkers such as glutathione peroxidase-GPx and superoxid dismutase-SOD can assess oxidative status of the body. Oxidative stress imbalances trigger lipid immunogenic modification with important role in atherosclerosis onset process. The present study evaluates GPx-1 because this enzyme isoform is widely expressed in cardiac and vascular structures. Reduction of GPx-1 level indicates the need to correct oxidative imbalance, for prevention of early atherosclerosis onset and cardiovascular diseases. Also, lipid cellular membrane oxidation, under the agression of increased oxidation perturbates calcium transport inside endoplasmattic reticulum, thus affecting normal heart rhyhm (causing arrythmias).

Purpose
Determination of GPx-1-isoform enzyme in correlation with oxidative status and implicitly with demonstration of oxidative activity on lipids, with the production of oxydized lipoprotein (LDLox) and anti-oxydized lipoprotein autoantibodies (antiLDLox) and the early initiation of atherogenic endothelial dysfunction.
Patients and methods: The present study was conducted on 150 patients, aged between 20-45 years old, divided equally into three groups. All the selected patients were without structural cardiovascular pathology. The first two groups presented functional cardiac arrhythmic disorders. The first group (group I) presented only cardiac rhythm disturbances, while the second one (group II) associated also dyslipidemia. The third group (group III) was control, without cardiovascular manifestations or other pathology. Clinical and paraclinical explorations were performed (biochemical, imaging, electocardiogram). In all patients, the GPx-1 isoform was determined, in hemolyzate serum, using standard methods. At the same time, LDLox and antiLDLox antibodies levels were assessed.

Results
. Mean values of GPx1- isoform were decreased up to 73% in group I, compared to the control and up to 68% in group II, thus implying a proarrhythmogenic oxidative status. In these patients, both dyslipidemic and non-dyslipidemic, the association of decreased GPx enzyme with a high oxidative status for lipids was observed by associating increased lipid oxidation biomarkers - oxidized LDL up to 140% in group I and 177% in group II. Also, as response, a concomitant increase of anti-LDLox autoantibodies was correlated (124% for group I and 156% for group II), indicating increased immunogenesis and the risk of endothelial immune inflammation.

Conclusions
1. GPx1 isoenzyme is a biomarker that reflects the existence of oxidative stress and also the risk of early development of lipid oxidation.
2. Decreased GPx level correlates with increased LDLox and antiLDLox autoantibodies levels.
3. GPx evaluation is a necessity in assessing early atherogenic risk and arrhythmogenic potential.
4. Early correction of GPx (through diet, antioxidants) may constitute a prophylaxis of early atherosclerosis and its severe cardiovascular consequences.