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Published on: May 17, 2024
microRNA-33A expression is reduced in cerebral cortex in a rat model of ischemic tolerance
1Henan Provincial People's Hospital Department of Neurology Zhengzhou China fengyanfy1028@163.com.
Abstract:
This study examined the microRNA—33a (miR—33a) expression levels in cerebral cortex in rat model of cerebral ischemic tolerance (IT), with 3—nitropropionic acid (3—NPA) preconditioning. Rat model of cerebral IT was established as follows: 14 male Sprague—Dawley rats were randomly divided into two groups, the 3—NPA treated group and the control group. Intraperitoneal injection of 3—NPA or normal saline was performed in 3—NPA treated group and control group, respectively. Middle cerebral artery occlusion (MCAO) was performed in all the rats 3 days after injection and the infarct volume was measured on postoperative day—2. To study miR—33a expression levels in this model, male Sprague—Dawley rats (n = 31) were randomly divided into 4 groups, 3—NPA treatment group (n = 8), 3—NPA treatment + MCAO group (n = 9), MCAO group (n = 9), and control group (n = 5). Surviving rats were sacrificed 4 days after injection and cerebral cortex samples were obtained for total RNA isolation. MiR—33a expression levels were determined by real—time quantitative PCR (qRT—PCR). Infarct volume in 3—NPA treated group decreased significantly in comparison to the control group (P < 0.05). Expression analysis by qRT—PCR revealed that miR—33a expression levels in 3—NPA treated group were significantly higher than that in control group (P < 0.05). However, no statistically significant difference in miR—33a expression levels were observed in 3—NPA + MCAO and MCAO groups (both P > 0.05). Our results present convincing evidence that miR—33a expression levels are significantly reduced in the cerebral cortex in rat model of cerebral IT, which may have significantly impacted the infarct volume.
Insights
This study investigated microRNA-33a (miR-33a) levels in a rat model of cerebral ischemic tolerance. Preconditioning with 3-nitropropionic acid (3-NPA) reduced infarct volume and increased miR-33a expression.
Area of Science:
- Neuroscience
- Molecular Biology
- Biochemistry
Background:
- Cerebral ischemic tolerance (IT) is a phenomenon where brain tissue becomes resistant to subsequent ischemic insults.
- MicroRNAs (miRNAs) play crucial roles in regulating gene expression and are implicated in various cellular processes, including neuroprotection.
- Understanding the molecular mechanisms underlying cerebral IT is vital for developing effective therapeutic strategies.
Purpose of the Study:
- To investigate the expression levels of microRNA-33a (miR-33a) in the cerebral cortex of a rat model of cerebral ischemic tolerance (IT).
- To explore the potential role of miR-33a in the development of cerebral ischemic tolerance induced by 3-nitropropionic acid (3-NPA) preconditioning.
- To correlate miR-33a expression levels with infarct volume in the context of cerebral ischemia.
Main Methods:
- Establishment of a rat model of cerebral ischemic tolerance using 3-nitropropionic acid (3-NPA) preconditioning followed by middle cerebral artery occlusion (MCAO).
- Quantification of infarct volume in the cerebral cortex using established methods.
- Measurement of miR-33a expression levels in cerebral cortex samples using real-time quantitative PCR (qRT-PCR).
Main Results:
- 3-NPA preconditioning significantly reduced infarct volume in the rat model of cerebral IT compared to the control group (P < 0.05).
- miR-33a expression levels were significantly higher in the 3-NPA treated group compared to the control group (P < 0.05).
- No statistically significant differences in miR-33a expression levels were observed between the 3-NPA + MCAO group and the MCAO group (P > 0.05).
Conclusions:
- miR-33a expression is significantly altered in the cerebral cortex of rats exhibiting cerebral ischemic tolerance.
- The observed changes in miR-33a expression may play a role in the protective mechanisms underlying cerebral ischemic tolerance.
- Further research is warranted to elucidate the precise mechanisms by which miR-33a influences infarct volume and neuroprotection.
