Hippocampal β2‑microglobulin mediates sepsis‑induced cognitive impairment

Area of Science:

• Neuroscience
• Immunology
• Pathology

Background:

• Sepsis frequently leads to acute brain dysfunction, neurocognitive deficits, and mortality.
• The mechanisms underlying sepsis-induced cognitive impairment are not fully understood.
• Beta-2 microglobulin (a component of MHC class I) is implicated in cognitive dysfunction in other neurological conditions.

Purpose of the Study:

• To investigate the role of beta-2 microglobulin in the brain in mediating sepsis-induced cognitive impairment.
• To test the hypothesis that beta-2 microglobulin contributes to sepsis-related neurocognitive deficits.

Main Methods:

• Utilized a cecal ligation and puncture (CLP) model in wild-type and antigen processing 1 (Tap1)-deficient mice.
• Assessed survival rates, cognitive function (anxiety-like behavior, contextual memory), and biochemical markers in the hippocampus.
• Tap1-deficient mice exhibit reduced cell surface expression of MHC class I.

Main Results:

• CLP induced anxiety-like behavior and impaired hippocampal memory in wild-type mice.
• Sepsis in wild-type mice led to microglial activation, increased IL-1β, and decreased BDNF and PSD-95 in the hippocampus.
• Tap1-deficient mice were protected from sepsis-induced cognitive deficits and exhibited reversed biochemical changes.

Conclusions:

• Beta-2 microglobulin appears to negatively regulate cognitive impairment in a mouse model of sepsis.
• Targeting beta-2 microglobulin may offer a therapeutic strategy for sepsis-induced brain dysfunction.