PLASMA LEVELS OF microRNA-122, ADAM17 AND THEIR ASSOCIATION WITH LIPIDS IN HYPERTENSIVE PATIENTS IN ENUGU, SOUTH-EAST NIGERIA

Abstract

Dyslipidaemia is a major risk factor for development of atherosclerosis and cardiovascular
disease. Coexistence of risk factors as seen in coexistence of dyslipidaemia and
hypertension further increases this risk. The aim of this work was to determine the
association of lipids with the plasma levels of miRNA-122 and ADAM17. miRNA-122
has been found to promote lipogenesis and also has ADAM17 as its direct putative target.
Hence, therapeutically targeting miRNA-122 might have a potential for treating
dyslipidaemia.
This cross-sectional study was done with 200 hypertensive patients recruited from the
outpatient clinic of the University of Nigeria Teaching Hospital, Enugu, and another 200
age and sex-matched, normotensive controls. Plasma ADAM17 was analyzed by Enzyme
Linked Immunosorbent Assay while miRNA-122 was extracted using Strategene miRNA
Isolation kit and quantified using Polymerase Chain Reaction. Total cholesterol,
triglycerides and high-density cholesterol were analyzed using enzymatic methods, and
low-density cholesterol calculated using Friedewald equation. Correlation was done using
Pearson’s correlation coefficient. A p-value of <0.05 was considered statistically
significant.
Prevalence of dyslipidaemia was found to be 44% in hypertensives and 23.5% in controls.
Dyslipidaemic hypertensives had significantly higher mean values of ADAM17 (3.7 + 0.9
11

ng/mL), miRNA-122 (1389.4 + 578.2 copies/5µL of cDNA), Total Cholesterol (5.7 + 1.6
mmol/L), and LDL (4.3 + 1.1 mmol/L) than the non-dyslipidaemic hypertensives with
ADAM17 (1.9 + 0.6 ng/mL), miRNA-122 (668.3 + 135.6 copies/5µL of cDNA), Total
Cholesterol (4.7 + 0.8 mmol/L), and LDL (3.0 + 0.6 mmol/L). Dyslipidaemic controls
equally had significantly higher mean values of ADAM17 (3.0 + 0.8 ng/mL), miRNA-122
(1351.4 + 167.4 copies/5µL of cDNA), Total Cholesterol (5.5 + 2.2 mmol/L), and LDL
(3.6 + 1.8 mmol/L), than the non-dyslipidaemic controls with ADAM17 (1.7 + 0.5 ng/mL),
miRNA-122 (647.8 + 110.0 copies/5µL of cDNA), Total Cholesterol (4.0 + 0.7 mmol/L),
and LDL (2.2 + 0.7 mmol/L). A strong positive correlation was seen between ADAM17
and miRNA-122, r = 0.82, p< 0.05. miRNA-122 was also positively correlated with LDL
Cholesterol and Total Cholesterol, r = 0.53, p<0.05 and r= 0.51 p< 0.05 respectively.
Correlation of miRNA-122 with triglycerides and HDL-Cholesterol was however weak,
r = 0.1, p> 0.05 and r = -0.1, p> 0.05 respectively.
From the foregoing, higher levels of miRNA-122 and ADAM17 in dyslipidaemic
individuals and the significant positive correlation with lipids supports their stimulant role
in lipogenesis, and the possible benefit of having them as therapeutic targets in treating
dyslipidaemia and ameliorating cardiovascular diseases.

PLASMA LEVELS OF microRNA-122, ADAM17 AND THEIR ASSOCIATION WITH LIPIDS IN HYPERTENSIVE PATIENTS IN ENUGU, SOUTH-EAST NIGERIA