Abstract W MP38: Apolipoprotein A-I (ApoA-I) Mimetic Peptide, D-4F, Regulates miRNA Expression and Improves Functional Outcome after Stroke in Diabetic Rats

Abstract

Introduction: Diabetes mellitus (DM) in patients is associated with low high-density lipoprotein cholesterol (HDL-C) and impairment of the anti-oxidative capacity of HDL-C. Several miRNAs have been identified as having a physiological role in tissues in which diabetes complications occur. D-4F is an economical ApoA-I mimetic peptide which increases HDL function. We therefore investigated the therapeutic effect and underlying mechanisms of D-4F treatment of stroke induced functional benefit effects in type one DM (T1DM) rats. Methods: T1DM was induced in Wistar rats by streptozotocin (60mg/kg, ip) .Subsequently they were subjected to embolic middle cerebral artery occlusion. D-4F (10 mg/kg i.p.) was administered at 2h, 24h and 48h after stroke. Functional outcomes, brain blood barrier (BBB) leakage and lesion volume were evaluated. Results: D-4F treatment of stroke in T1DM rats significantly decreased Evans Blue dye leakage (15.85±1.52 ng/mg vs contro: 30.57± 5.88 ng/mg) and significantly improved functional outcome compared to non-treatment T1DM-control. D-4F treatment significantly increased miR-124a and miR-181c, but decreased miR-200b expression in the ischemic brain. Using laser capture, D-4F also significantly increased ischemic brain endothelial cell miR-126 expression compared to non-treatment control. In addition, D-4F treatment significantly decreased miR-181c target gene tumor necrosis factor-a (TNF-a), and miR-124a target gene monocyte chemoattractant protein-1 (MCP1) expression. D-4F also decreased proinflammatory nuclear NFkB (26.07±3.17 vs 37.43±3.47), Toll-like receptor 4 (TLR4, 7.26±0.69 vs 10.5±1.2), matrix metalloproteinase 9 (MMP9, 0.16±0.04 vs 0.48±0.09) expression, and increased CD163 (M2 macrophage marker, 120.98±8.13 vs 85.02± 9.47) number compared to T1DM-MCAo control rats. Conclusion: D-4F treatment of stroke in T1DM rats regulates miRNA expression and their target gene and protein expression and induces anti-inflammatory effects and promotes M2 macrophage polarization which may contribute to D-4F decreased BBB leakage and induced functional benefit effects after stroke in T1DM rats.