Upregulation of MiRNA-149-5p Reduces the Infract Volume in Middle Cerebral Artery Occlusion Rats by Modulating Cation-Chloride Cotransporters Expressions

Abstract

Background: Brain ischemia often leads to the chloride gradient alternations, which affects volume regulation and neuronal survival. Increase in NKCC1 expression and reduction in KCC2 level under ischemic condition results in inflammation and neuronal death. In this study, we investigated the effect of mimic miRNA and coenzyme Q10 (CoQ10) on the expression of cation-chloride cotransporters (CCCs) (NKCC1 and KCC2) after cerebral ischemia.

Methods: In this study, cerebral ischemia was modeled using the middle cerebral artery occlusion method. Rats were randomly divided into six groups: sham, model, negative control, vehicle, and the first and second treatments. In the Sham group, ischemia was not induced, and no treatment was performed. In the Model group, ischemia induction was performed, and other groups, in addition to ischemia induction, received Scramble miRNA, Ethanol, mimic miRNA-149-5p and CoQ10, respectively. Each group was divided into three subgroups to assess the volume of the tissue damage and neurological deficits scores (NDS) in subgroup 1, brain water content in subgroup 2, level of miRNA-149-5p and CCC expressions in subgroup 3.

Results: Our data suggested that the use of mimic miRNA and Q10 increased the level of miRNA-149 and KCC2 expression and decreased NDS, NKCC1 expression, brain water content, and infract volume.

Conclusion: Findings of this study suggest that the mimic miRNA and Q10 may have neuroprotective effects through reducing infract volume and brain water content and modulating the expression of CCCs after brain ischemia.

Keywords: Brain edama; Brain ischemia; Coenzyme Q10; MicroRNAs.

Fig. 1

Changes of miRNA-149-5p following cerebral ischemia and treatment with mimic miRNA and CoQ10. The data are expressed as the mean ± SEM. ^**p < 0.01 compared to Sham Group; ^##p < 0.01 compared to MCAO Model, NC, and Vehicle groups; ^###p < 0.001 compared to MCAO Model, NC and Vehicle groups; ^&&&p < 0.001 compared to mimic miRNA group (n = 6)

Fig. 2

Evaluation of NDS following cerebral ischemia and treatment with mimic miRNA and CoQ10. The data are expressed as the mean ± SEM. ^#p < 0.05 compared to MCAO Model, NC, and vehicle groups; ^##p < 0.01 compared to MCAO Model, NC, and Vehicle groups; ^&p < 0.05 compared to mimic miRNA group (n = 6).

Fig. 3

NKCC1 changes following cerebral ischemia and treatment with mimic miRNA and CoQ10. The data are expressed as the mean ± SEM. ^***p < 0.001 compared to Sham group; ^###p < 0.001 compared to MCAO Model group; ^$$p < 0.01 compared to NC and Vehicle groups (n = 6)

Fig. 4

Changes of KCC2 following cerebral ischemia and treatment with mimic miRNA and CoQ10. The data are expressed as the mean ± SEM. ^***p < 0.001 compared to sham group; ^###p < 0.001 compared to MCAO Model, NC, and vehicle groups (n = 6)

Fig. 5

Sample of coronal sections of rat brain stained with 2% TTC solution (A) and changes in the volume of tissue damage in studied groups in cortical and subcortical regions (B-D). The red and white areas indicate the healthy and damaged areas, respectively. In sham group rats, no white area is visible, while in the Model rats, almost half of the sections are white. Treatment with mimic miRNA and CoQ10 resulted in a decrease in white areas compared to the MCAO Model group. The lines above the images indicate a length of 1 cm. The data are expressed as the mean ± SEM. ^##p < 0.01 compared to MCAO Model, NC, and Vehicle groups; ^###p < 0.001 compared to MCAO Model, NC, and Vehicle groups; ^&&p < 0.01) compared to mimic miRNA group; ^&&&p < 0.001 compared to mimic miRNA group (n = 6)

Fig. 6

Changes in the brain water content of the damaged (right) and healthy (left) hemispheres of rats in the studied groups. The data are expressed as the mean ± SEM. ^***p < 0.001 compared to sham group; ^##p < 0.01 compared to MCAO Model, NC, and Vehicle groups; ^&p < 0.1 compared to mimic miRNA group; ^{^^^}p < 0.001 and ^{^^}p < 0.01 compared to opposite hemisphere in the same group (n = 6)