Dynamic Brain Lipid Profiles Modulate Microglial Lipid Droplet Accumulation and Inflammation Under Ischemic...

Area of Science:

• Neuroscience
• Immunology
• Cell Biology

Background:

• Microglia are key players in post-stroke inflammation.
• Lipid droplet (LD) accumulation in microglia is linked to dysfunction and inflammation in aging and neurodegenerative diseases.
• The role of LD-rich microglia (LDRM) in stroke remains unclear.

Purpose of the Study:

• To investigate microglial LD accumulation patterns and inflammatory signaling during stroke.
• To explore the temporal and spatial dynamics of lipid profiles and microglial phenotypes post-stroke.
• To elucidate the relationship between microglial lipid metabolism and inflammatory responses in ischemic brain injury.

Main Methods:

• Utilized in vitro and in vivo stroke models.
• Analyzed microglial LD accumulation and perilipin 2 (PLIN2) expression.
• Assessed inflammatory markers (TNF-α, IL-6, IL-1β) and gene expression related to lipid metabolism.
• Examined spatial and temporal lipid profile dynamics, including cholesteryl ester and triacylglycerol levels.

Main Results:

• Microglia showed increased LD accumulation and PLIN2 expression under hypoxia and stroke conditions.
• LDRM exhibited a pro-inflammatory phenotype with elevated TNF-α, IL-6, and IL-1β.
• Distinct spatial and temporal changes in lipid profiles, particularly cholesteryl esters and triacylglycerols, were observed.
• Differential expression of lipid metabolism-related genes was noted in LDRM.

Conclusions:

• Stroke induces significant LD accumulation and pro-inflammatory activation in microglia.
• Microglial lipid profiles dynamically change post-ischemia, exacerbating inflammation.
• A reciprocal relationship exists between microglial phenotype, lipid metabolism, and brain injury progression during stroke.