Decoding mitochondrial apoptosis in ischemic stroke via a miR-21a-3p/Plaur-centered regulatory network

Area of Science:

• Neuroscience
• Molecular Biology
• Genetics

Background:

• Ischemic stroke causes significant death and disability.
• Current therapies offer limited protection against secondary brain injury.
• Mitochondrial-dependent cell death pathways are implicated, but regulatory networks are unclear.

Purpose of the Study:

• To identify key regulators of mitochondrial apoptosis in ischemic stroke.
• To elucidate cell type-specific responses to ischemia.
• To investigate the role of microRNAs (miRNAs) in regulating these pathways.

Main Methods:

• Integrated single-cell RNA sequencing (scRNA-seq), bulk RNA sequencing, and miRNA profiling in mouse models of ischemic stroke.
• Analyzed cell type composition and differential gene expression using scRNA-seq.
• Validated findings in hypoxia-treated microglia and endothelial cells using molecular and cellular assays.

Main Results:

• scRNA-seq revealed significant changes in endothelial cells, monocytes, astrocytes, and microglia, highlighting 'apoptotic mitochondrial changes'.
• The Plaur gene was identified as a key dysregulated gene, particularly in endothelial and myeloid cells.
• miR-21a-3p was identified as a direct upstream regulator of Plaur, and this axis attenuated hypoxia-induced cell injury in vitro.

Conclusions:

• The miR-21a-3p/Plaur axis connects miRNA regulation to mitochondrial apoptotic and oxidative damage pathways.
• This pathway represents a potential therapeutic target for ischemic stroke.
• Further mechanistic and translational studies are warranted.