Neuroinflammation after ischemic stroke involves INPP5D expression mediated by the TMPO-AS1-PU.1 complex

Area of Science:

• Neuroscience
• Molecular Biology
• Genetics

Background:

• Ischemic stroke is a leading cause of death and disability worldwide.
• Long non-coding RNAs (lncRNAs) are increasingly recognized for their roles in various diseases, including stroke.
• The specific role of lncRNA TMPO-AS1 in ischemic stroke pathogenesis remains largely unexplored.

Purpose of the Study:

• To investigate the role of lncRNA TMPO-AS1 in ischemic stroke.
• To elucidate the underlying molecular mechanisms by which TMPO-AS1 influences neuroinflammation and stroke outcomes.

Main Methods:

• Established a middle cerebral artery occlusion (MCAO) mouse model of ischemic stroke.
• Utilized hypoxia/glucose deprivation/reoxygenation (OGD/R) in BV2 cells to mimic ischemic conditions.
• Interfered with TMPO-AS1 expression using shRNA lentivirus and assessed protein and gene expression, inflammatory cytokine secretion, and cell viability.
• Employed RNA immunoprecipitation (RIP), PNA-pull down, luciferase reporter, and chromatin immunoprecipitation (ChIP) assays to determine molecular interactions and transcriptional activity.

Main Results:

• TMPO-AS1 levels were elevated in ischemic stroke patients, MCAO mice, and OGD/R-induced BV2 cells.
• TMPO-AS1 interference significantly inhibited neuroinflammation in OGD/R-induced BV2 cells.
• TMPO-AS1 enhanced nuclear accumulation of PU.1 by binding to it, thereby promoting INPP5D transcription.
• Overexpression of INPP5D reversed the anti-inflammatory effects of TMPO-AS1 interference.
• TMPO-AS1 interference reduced infarct volume and improved sensorimotor and cognitive functions in MCAO mice.

Conclusions:

• lncRNA TMPO-AS1 plays a critical role in exacerbating neuroinflammation and stroke progression.
• The TMPO-AS1-PU.1 complex promotes INPP5D expression, contributing to stroke pathology.
• Targeting TMPO-AS1 represents a potential therapeutic strategy for ischemic stroke.