Spermidine Inhibits M1 Microglia Polarization in a Mouse Model of Parkinson's Disease and BV2 Cells via NF-κB/STAT-1

Jun Shu1, Yuqiong Jiao1, Wenshi Wei1

  • 1Department of Neurology, Huadong Hospital, Fudan University, Shanghai, China.

Brain and Behavior
|March 10, 2025
PubMed
Abstract

Insights

Spermidine reduces M1 microglia activation and promotes M2 polarization, mitigating neuroinflammation and dopaminergic neuron death in Parkinson's disease models. This polyamine offers potential neuroprotection by modulating key signaling pathways.

Area of Science:

  • Neuroscience
  • Immunology
  • Pharmacology

Background:

  • Activated M1 microglia exacerbate neuroinflammation and neuronal death in Parkinson's disease (PD).
  • Spermidine, a natural polyamine, exhibits potential anti-inflammatory properties.
  • The precise role of spermidine in modulating microglial polarization and neuroinflammation in PD remains unclear.

Purpose of the Study:

  • To investigate the effects of spermidine on M1/M2 microglial polarization in Parkinson's disease models.
  • To elucidate the underlying molecular mechanisms of spermidine's action on neuroinflammation and neuroprotection.

Main Methods:

  • Utilized the MPTP mouse model of PD and LPS-stimulated BV2 cells.
  • Assessed microglial polarization using RT-PCR, western blotting, and immunofluorescence.
  • Analyzed the impact of spermidine on key signaling pathways (NF-κB, STAT1, p38 MAPK, STAT6) and neurotrophic factors (BDNF-TrkB-PI3K/AKT).

Main Results:

  • Spermidine pretreatment reduced M1 microglia activation and increased M2 phenotype in PD mice.
  • Spermidine decreased inflammatory factors and dopaminergic neuron death in vivo.
  • In vitro, spermidine protected neurons by modulating microglial polarization and activating the BDNF-TrkB-PI3K/AKT pathway, while inhibiting NF-κB, STAT1, and p38 MAPK pathways.

Conclusions:

  • Spermidine mitigates neuroinflammation in PD by shifting microglial polarization from M1 to M2.
  • The mechanism involves inhibiting NF-κB, STAT1, and p38 MAPK pathways while activating STAT6.
  • Spermidine confers indirect neuroprotection via the BDNF-TrkB-PI3K/AKT signaling cascade.