The Double-Edged Sword: A Structured Narrative Review of Microglial Phenotypic Transition as a Pivotal Driver and Therapeutic Target in Parkinson's Disease.
Level 5 - mechanism / opinion, no new human data
Structured narrative review synthesizing mechanistic and preclinical literature without new human clinical data
PubMed 42576524 · doi:10.2174/011570159X473857260708102204
What was done
A structured PubMed literature search was conducted up to December 2025 using search terms related to Parkinson's disease, microglia, neuroinflammation, alpha-synuclein, polarization, tunneling nanotubes, NF-κB, and NLRP3. Of 2,952 retrieved records, 147 studies addressing microglial polarization, neuroinflammation, alpha-synuclein pathology, and intercellular communication were selected and summarized.
What was found
The abstract reports qualitative mechanistic pathways without quantitative numerical data. In early stages, microglia clear alpha-synuclein via autophagy, donate healthy mitochondria, and transfer excess alpha-synuclein through tunneling nanotubes. Progressive alpha-synuclein accumulation drives microglia toward an M1 pro-inflammatory phenotype via TLR2/4, TREM2, MHCII, and RAGE activation, triggering NF-κB and NLRP3 signaling, cytokine release, and NOX2-mediated reactive oxygen species that injure dopaminergic neurons and disrupt the blood-brain barrier.
Why it matters
The review provides a comprehensive mechanistic framework for how the microglial functional switch promotes Parkinson's pathology, framing microglial polarization as a potential target for therapeutic intervention.
Limits
The synthesized evidence is heavily weighted toward preclinical in vitro and animal models rather than clinical human data. No quantitative meta-analysis was performed, and specific clinical biomarkers for microglial state transitions remain undefined.
Cited by
- supports Microglial cells support blood-brain barrier maintenance, but this maintenance is impaired when microglia switch to the pro-inflammatory M1 phenotype.