Related Experiment Video
Updated: Jun 2, 2026
Isolation of Cortical Microglia with Preserved Immunophenotype and Functionality From Murine Neonates
Published on: January 30, 2014
Expression of mutant alpha-synuclein modulates microglial phenotype in vitro
Lalida Rojanathammanee1, Eric J Murphy, Colin K Combs
1Department of Pharmacology, Physiology, & Therapeutics, University of North Dakota School of Medicine and Health Sciences, 504 Hamline Street, Neuroscience Building, Grand Forks, ND 58203, USA.
Background:
Increased reactive microglia are a histological characteristic of Parkinson's disease (PD) brains, positively correlating with levels of deposited α-synuclein protein. This suggests that microglial-mediated inflammatory events may contribute to disease pathophysiology. Mutations in the gene coding for α-synuclein lead to a familial form of PD. Based upon our prior findings that α-synuclein expression regulates microglial phenotype we hypothesized that expression of mutant forms of the protein may contribute to the reactive microgliosis characteristic of PD brains.
Methods:
To quantify the effects of wild type and mutant α-synuclein over-expression on microglial phenotype a murine microglial cell line, BV2, was transiently transfected to express human wild type (WT), and mutant α-synuclein (A30P and A53T) proteins. Transfected cells were used to assess changes in microglia phenotype via Western blot analysis, ELISA, phagocytosis, and neurotoxicity assays.
Results:
As expected, over-expression of α-synuclein induced a reactive phenotype in the transfected cells. Expression of α-synuclein increased protein levels of cycloxygenase-2 (Cox-2). Transfected cells demonstrated increased secretion of the proinflammatory cytokines, tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), as well as increased nitric oxide production. Transfected cells also had impaired phagocytic ability correlating with decreased protein levels of lysosomal-associated membrane protein 1 (LAMP-1). In spite of the increased cytokine secretion profile, the transfected cells did not exhibit increased neurotoxic ability above control non-transfected BV2 cells in neuron-microglia co-cultures.
Conclusions:
These data demonstrated that over-expression of α-synuclein drives microglial cells into a form of reactive phenotype characterized by elevated levels of arachidonic acid metabolizing enzymes, cytokine secretion, and reactive nitrogen species secretion all superimposed upon impaired phagocytic potential.
Insights
Over-expressing alpha-synuclein (α-synuclein) in microglia triggers a reactive inflammatory state, increasing pro-inflammatory cytokines and impairing phagocytosis. This suggests a role for α-synuclein in Parkinson's disease pathology.
Area of Science:
- Neuroscience
- Immunology
- Cell Biology
Background:
- Reactive microglia and alpha-synuclein (α-synuclein) protein deposits are hallmarks of Parkinson's disease (PD).
- Microglial inflammation is implicated in PD pathogenesis, with mutations in α-synuclein linked to familial PD.
- Prior studies indicate α-synuclein regulates microglial phenotype, prompting investigation into mutant forms' role in PD-associated microgliosis.
Purpose of the Study:
- To investigate how wild type and mutant α-synuclein expression affects microglial cell phenotype.
- To determine if α-synuclein overexpression influences inflammatory markers, phagocytic capacity, and neurotoxicity in microglia.
Main Methods:
- Murine microglial cell line (BV2) was transiently transfected with human wild type (WT), A30P, and A53T mutant α-synuclein.
- Assessed microglial phenotype changes using Western blot, ELISA, phagocytosis assays, and neurotoxicity assays.
Main Results:
- Overexpression of α-synuclein induced a reactive microglial phenotype, increasing cyclooxygenase-2 (Cox-2) levels.
- Transfected cells showed elevated secretion of pro-inflammatory cytokines (TNF-α, IL-6) and nitric oxide production.
- Phagocytic ability was impaired, evidenced by decreased lysosomal-associated membrane protein 1 (LAMP-1) levels, but neurotoxicity did not increase.
Conclusions:
- Overexpression of α-synuclein induces a reactive microglial phenotype characterized by increased inflammatory mediator secretion and impaired phagocytosis.
- These findings highlight a potential mechanism by which α-synuclein contributes to neuroinflammation in Parkinson's disease.
More Related Videos
09:16Exogenous Administration of Microsomes-associated Alpha-synuclein Aggregates to Primary Neurons As a Powerful Cell Model of Fibrils Formation
Published on: June 26, 2018
09:32Bioluminescence Imaging of Neuroinflammation in Transgenic Mice After Peripheral Inoculation of Alpha-Synuclein Fibrils
Published on: April 13, 2017