Microglia contribute to bipolar depression through Serinc2-dependent phospholipid synthesis

Ying-Han Wang1, Chong-Lei Fu2, Lin-Bo Chen1

  • 1State Key Laboratory of Membrane Biology, IDG/McGovern Institute for Brain Research, School of Life Sciences, Tsinghua University, Beijing 100084, China.

Insights

Serine-3 (Serinc2) deficits in microglia contribute to bipolar disorder (BD) by impairing synaptic pruning. Reduced Serinc2 expression in BDII patients correlates with disease severity, suggesting a potential therapeutic target.

Area of Science:

  • Neuroscience
  • Immunology
  • Genetics

Background:

  • Microglia play a role in bipolar disorder (BD) pathogenesis through inflammatory and immune responses.
  • The specific contribution of microglia to BD remains incompletely understood.

Purpose of the Study:

  • To investigate the role of Serine-3 (Serinc2) in BD susceptibility and pathogenesis.
  • To elucidate the mechanisms by which microglial Serinc2 influences BD-related behaviors.

Main Methods:

  • Analysis of Serinc2 expression in BDII patient plasma.
  • Utilized induced pluripotent stem cell (iPSC)-derived microglia-like cells from BDII patients.
  • Generated microglia-specific Serinc2-deficient mouse models.
  • Combined iPSC-microglia and mouse models to study Serinc2 function.

Main Results:

  • Reduced Serinc2 expression was observed in BDII patient plasma and iPSC-derived microglia, correlating with disease severity.
  • Microglial Serinc2 deficiency led to decreased synaptic pruning and depression-like behaviors in mice.
  • Serinc2 deficits impaired serine-related phospholipid synthesis, affecting microglial membrane CR3 formation and synaptic pruning signals.

Conclusions:

  • Microglial Serinc2 deficits are associated with BD susceptibility and pathogenesis.
  • Impaired synaptic pruning due to Serinc2-dependent lipid alterations contributes to BD-related behavioral abnormalities.
  • Serinc2 represents a potential target for understanding and treating BD.