Abstract. MicroRNAs (miRNAs or miRs) are small (19-23 nt) non-coding RNA molecules that are endogenous regulators of gene expression. Previous studies have found that some miRNAs are related to the progression of ischemia in the cerebral artery. Furthermore, a recent study found a significant association between miRNA single nucleotide polymorphisms (SNPs) and the risk of ischemic stroke. Therefore, it may be valuable to investigate associations between megakaryocyte formationrelated miRNA polymorphisms and the prevalence of ischemic stroke. We thus conducted a case-control study of 1,000 individuals who were screened for 4 miRNA polymorphisms (miR-34a rs6577555C>A, miR-130a rs731384C>T, miR-150 rs73056059G>A and miR-155 rs767649T>A) by PCR-RFLP analysis. The study population comprised 596 patients with ischemic stroke and 404 control subjects without any history of neurological disorders. We observed associations between miRNA polymorphisms and individual stroke subtypes. The miR-150 polymorphisms were significantly associated with ischemic stroke subgroups, such as left anterior descending artery (LAD) disease [GG vs. AA: adjusted odds ratio (AOR), 1.922; 95% confidence interval (CI), 1.003-3.681] and cardioembolism (GG vs. AA: AOR, 2.996; 95% CI, 1.293-6.939). Additionally, Cox proportional analysis indicated that the miR-150GA genotype was associated with survival in patients with ischemic stroke [adjusted hazard ratio (HR), 2.063; 95% CI, 1.142-3.727; P= 0.017] and with the LAD subgroup [adjusted HR, 3.021; 95% CI, P=0.008]. Our findings suggest that miR-150 polymorphisms may contribute to the development of ischemic stroke and may potentially act as biomarkers to predict the risk of ischemic stroke. To the best of our knowledge, this is the first study to evaluate the association between miRNA polymorphisms (miR-34aC>A, miR-130aC>T, miR-150G>A and miR-155T>A) and ischemic stroke.

Background and PurposeMicroRNA (miRNA) expression has been examined in multiple conditions, including various cancers, neurological diseases, and cerebrovascular diseases, particularly stroke. Existing evidence indicates that miRNA biosynthesis and function play crucial roles in ischemic stroke physiology and pathology. In this study, we selected six known polymorphisms in miRNA-biogenesis genes; DICER rs13078A>T, rs3742330A>G; DROSHA rs10719T>C, rs6877842G>C; Ran GTPase (RAN) rs14035C>T; exportin 5 (XPO5) rs11077A>C. MethodsWe analyzed the associations between these polymorphisms and disease status and clinical factors in 585 ischemic stroke patients and 403 controls. Genotyping was performed with the polymerase chain reaction-restriction fragment length polymorphism method. ResultsThe DICER rs3742330A>G (AA vs. AG+GG: adjusted odds ratio [AOR], 1.360; 95% confidence interval [CI], 1.024 to 1.807; P=0.034) and DROSHA rs10719T>C polymorphisms (TT vs. CC: AOR, 2.038; 95% CI, 1.113 to 3.730; P=0.021) were associated with ischemic stroke prevalence. During a mean follow-up of 4.80±2.11 years, 99 (5.91%) of the stroke patients died. In multivariate Cox proportional hazard regression models, a significant association was found between RAN rs14035 and survival of large artery disease patients with ischemic stroke (CC vs. TT: adjusted hazard ratio, 5.978; P=0.015). ConclusionsAn association was identified between the DICER and DROSHA polymorphisms and ischemic stroke. Specifically, polymorphisms (rs3742330 and rs10719) were more common in stroke patients, suggesting that they may be associated with an increased risk of ischemic stroke.

Several studies have demonstrated the beneficial effect of mesenchymal stem cells (MSCs) on intracerebral hemorrhage (ICH). Enhancement of the therapeutic efficacy of MSCs in ICH is necessary, considering the diseases high association with mortality and morbidity. Various preconditioning methods to enhance the beneficial properties of MSCs have been introduced. We suggested apocynin, a well-known nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitor, as a novel preconditioning regimen to enhance the therapeutic efficacy of MSCs in ICH. Rat ICH models were made using bacterial collagenase. 24 h after ICH induction, the rats were randomly divided into apocynin-preconditioned MSC-treated (Apo-MSC), naïve MSC-treated and control groups. Hematoma volume, brain edema, and degenerating neuron count were compared at 48 h after the ICH induction. The expression of tight junction proteins (occludin, zona occludens [ZO]-1) were also compared. Hematoma size, hemispheric enlargement and degenerating neuron count were significantly lower in the Apo-MSC group than in the naïve MSC group (p = 0.004, 0.013 and 0.043, respectively), while the expression of occludin was higher (p = 0.024). Apocynin treatment enhances the therapeutic efficacy of MSCs in ICH in the acute stage, through the improvement of the beneficial properties of MSCs, such as neuroprotection and the reinforcement of endovascular integrity of cerebral vasculature.