THE CONTENT OF ENDOTHELIN-1 IN THE BLOOD PLASMA OF PATIENTS WITH DIABETIC RETINOPATHY ON THE BACKGROUND OF TYPE 2 DIABETES DEPENDING ON THE POLYMORPHIC VARIANTS OF THE MTHFR, MTRR AND MTR GENES

Abstract

Backround. The vascular and extravascular microcirculation of the eye is a rich source of endothelin-1 (ET-1), which can contribute to abnormal retinal hemodynamics in diabetic retinopathy. In patients with type 2 diabetes mellitus (T2DM), an increase in the level of circulating ET-1 was found, and a positive correlation between its levels in the blood was found and degree of microangiopathy. Strengthens the development of endothelial dysfunction and microvascular complications, a high level of homocysteine, which occurs due to a genetically determined deficiency of enzymes of the folate cycle, determines in the body what, because homocysteine ​​causes a violation of the structure of endothelial cells. Aim: to study the ET-1 content in the blood plasma of patients with diabetic retinopathy against the background of type 2 diabetes, depending on the polymorphic variants of the MTHFR, MTRR and MTR genes, as an important pathogenetic pathway for the development of endothelial dysfunction. Materials and methods. The study included 83 patients (83 eyes) with T2DM, in whom non-proliferative and proliferative DR were found according to the results of an ophthalmological examination using the ETDRS scale. The control group (CG) included 35 people without diabetes, who were matched with patients by gender, age, and body mass index. Gene polymorphism was determined using real-time PCR on the automatic amplifier Gene Amp® PCR System 7500, the content of ET-1 was determined in blood plasma by the ELISA method. Conclusion. The SS genotype of the rs1801133 gene, the GG genotype of the rs1805087 gene, the AS polymorphism, and the SS genotype of the rs1801131 gene can be considered potential risk factors for the development of DR on the background of type 2 diabetes. The SS genotype of the rs1801133 gene was accompanied by a maximum 14-fold increase in ET-1 in patients with DR. The minor GG genotype of the rs1805087 gene was found only in patients with DR, and was characterized by the maximum content of ET-1. In the carriers of AS polymorphism of the rs1801131 gene, an 8-fold increase in ET-1 was found during the development of DR. The minor GG genotype of the rs1805087 gene was found only in patients with DR, and was characterized by the maximum content of ET-1. In the carriers of AS polymorphism of the rs1801131 gene, an 8-fold increase in ET-1 was found during the development of DR. The minor SS genotype of this gene was twice as common in patients, and the ET-1 content increased 5 times with the development of DR. The presence of ST polymorphism of the rs1801133 gene and the AA genotype of rs1801131 are probably factors that prevent the development of DR. The ST gene rs1801133 polymorphism was accompanied by the lowest ET-1 content. The AA genotype of the rs1801131 gene was 1.3 times less frequent, the ET-1 content in these individuals was the lowest and practically did not change during the development of DR.