LPS and palmitic acid Co-upregulate microglia activation and neuroinflammatory response

Area of Science:

• Neuroscience
• Immunology
• Biochemistry

Background:

• Neuroinflammation is linked to psychiatric disorders, but mechanisms are unclear.
• Microglia are key players in neuroinflammation and response to inflammatory stimuli.
• Metabolic syndrome and type 2 diabetes involve increased saturated fatty acids (SFAs) and lipopolysaccharide (LPS).

Purpose of the Study:

• To investigate if SFAs interact with LPS to activate microglia.
• To identify molecular pathways involved in SFA-LPS-induced neuroinflammation.

Main Methods:

• Used HMC3 human microglial cell line.
• Treated cells with lipopolysaccharide (LPS) and palmitic acid (PA), alone and in combination.
• Analyzed proinflammatory cytokine expression and signaling pathways (MAPK, NFκB, AP-1).
• Measured ceramide production and effects of co-culture with immune cells.

Main Results:

• Low-dose LPS and PA stimulated proinflammatory cytokine expression.
• Combined PA and LPS synergistically upregulated cytokines via MAPK, NFκB, and AP-1 pathways.
• PA increased ceramide production; LPS and PA further elevated it.
• Co-culture with macrophages and lymphocytes amplified the inflammatory response.

Conclusions:

• LPS and PA interact to activate microglia, inducing neuroinflammation and cytokine release.
• The MAPK, NFκB, and AP-1 pathways mediate this inflammatory response.
• Inhibiting microglia activation and reducing LPS/PA-induced inflammation may treat neuronal disorders.