MiR-21-5p protects against ischemic stroke by targeting IL-6R

Area of Science:

• Neuroscience
• Molecular Biology
• Genetics

Background:

• Ischemic stroke is a critical neurological condition resulting from vascular obstruction.
• MicroRNAs (miRNAs) play a significant role in regulating cellular processes and are implicated in ischemic stroke.
• Certain miRNAs demonstrate potential to mitigate ischemic injury, necessitating further investigation into their protective mechanisms.

Purpose of the Study:

• To identify and characterize protective microRNAs involved in the ischemia-reperfusion process in the context of ischemic stroke.
• To elucidate the specific role of hsa-miR-21-5p in protecting against ischemia-reperfusion injury.
• To investigate the molecular mechanism by which hsa-miR-21-5p exerts its protective effects, particularly its interaction with interleukin-6 receptor (IL-6R).

Main Methods:

• Analysis of peripheral RNA sequencing datasets (GEO) from ischemic stroke patients to identify differentially expressed miRNAs.
• Quantitative reverse transcription polymerase chain reaction (qRT-PCR) to measure miRNA expression levels in patients and healthy controls.
• Establishment of an in vitro ischemia-reperfusion model using oxygen-glucose deprivation (OGD) in HMEC-1 cells.
• Cell viability (MTT assay) and apoptosis (TUNEL assay) assessments, along with western blot analysis of apoptosis-related proteins.
• Luciferase reporter assays to confirm the direct binding and inhibitory effect of hsa-miR-21-5p on IL-6R gene expression.

Main Results:

• RNA-seq analysis revealed significantly lower expression of several miRNAs, including hsa-miR-21-5p, in ischemic stroke patients.
• hsa-miR-21-5p was found to directly bind to the 3'-untranslated region (3'-UTR) of the IL-6R gene, inhibiting its translation and leading to elevated IL-6R levels in patients.
• Overexpression of hsa-miR-21-5p in OGD-treated HMEC-1 cells enhanced cell viability and reduced apoptosis, effects that were diminished by IL-6R overexpression.

Conclusions:

• hsa-miR-21-5p is significantly decreased in the peripheral blood of ischemic stroke patients, while IL-6R levels are elevated.
• hsa-miR-21-5p directly targets and suppresses IL-6R expression, thereby alleviating cellular damage induced by oxygen-glucose deprivation.
• These findings highlight hsa-miR-21-5p as a potential therapeutic agent for mitigating ischemia-reperfusion injury in ischemic stroke.