Abstract P081: Expression Of Micro-rnas And Transfer Of Lipids To HDL In Vitro In Stroke Due To Hypertensive Emergency

Abstract

Objective: This study evaluates the association of expression of microRNAs (miRNAs) 221/222 and lipid transfer in ischemic stroke (IS) patients due to hypertensive emergency (HE). Methods: Thirty and one patients with IS due to hypertensive emergency (IS-HE), 33 individuals with IS without HE (IS), 31 controlled hypertensive (CHT) and 33 normotensive (NT) individuals were studied. The expression of miRNAs was performed by RT-q PCR (real-time quantitative polymerase chain reaction). The lipid transfer to high density lipoprotein cholesterol (HDLc) was evaluated after incubation of the plasma with an artificial nanoparticle used as a donor of esterified and non-esterified cholesterol, radiolabelled. Cholesterol transfer was measured in the HDLc fraction, after chemical precipitation of lipoproteins containing apolipoprotein B. Results: Systolic and diastolic blood pressure were significantly higher in the IS-HE compared to IS, CT and NT groups (162/99 mmHg vs 140/87, 128/69 and 129/82 mmHg, respectively; p<0.05). The miRNA-221 expression was higher in the IS-HE group compared to the IS, CHT and NT groups (4.23 vs 2.44, 1.35 and 1.05, respectively; p<0.003). MiRNA-222 showed overexpression in the IS-HE and IS groups compared to the CHT group (1.26 and 1.27 vs 0.24, respectively; p<0.0001). The esterified cholesterol transfer was reduced in the IS-HE and IS groups in relation to the CHT and NT groups (4.19 and 3.76 vs 4.5 and 4.75, respectively; p<0.05). Non-esterified cholesterol transfer was decreased in the IS-HE and IS groups compared to CHT and NT groups (4.57 and 4.06 vs 5.47 and 5.71, respectively; p<0.05). There was a negative correlation between miRNA-221 and esterified cholesterol transfer and also with free cholesterol. Conclusions: This study provides evidence of the miRNAs participation in IS-HE, suggesting that the increased expression of miRNAs-221/222 can be a biomarker in cases of IS, mainly associated to HE. In addition, lipid transfer to HDLc is decreased in patients with stroke and hypertensive emergency. This reduction was previously associated with coronary heart disease, but no with stroke. Therefore, HDLc functions can be reduced in ischemic stroke by hypertensive emergency, which can also contribute to atherogenic process.