Mast Cells Release Chemokine CCL2 in Response to Parkinsonian Toxin 1-Methyl-4-Phenyl-Pyridinium (MPP(+)).

Microglial activation and release of inflammatory cytokines and chemokines are crucial events in neuroinflammation. Microglial cells interact and respond to other inflammatory cells such as T cells and mast cells as well as inflammatory mediators secreted from these cells. Recent studies have shown that neuroinflammation causes and accelerates neurodegenerative disease such as Parkinson's disease (PD) pathogenesis. 1-methyl-4-phenyl-pyridinium ion (MPP(+)), the active metabolite of neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydro pyridine activates glial cells and mediate neurodegeneration through release of inflammatory mediators. We have shown that glia maturation factor (GMF) activates glia and induces neuroinflammation and neurodegeneration and that MPP(+) activates mast cells and release proinflammatory cytokines and chemokines. The chemokine (C-C motif) ligand 2 (CCL2) levels have been shown to be elevated and play a role in PD pathogenesis. In the present study, we analyzed if MPP(+) activates mouse and human mast cells to release chemokine CCL2. Mouse bone marrow-derived mast cells (BMMCs) and human umbilical cord blood-derived cultured mast cells (hCBMCs) were incubated with MPP(+) (10 µM) for 24 h and CCL2 levels were measured in the supernatant media by ELISA. MPP(+)-significantly induced CCL2 release from BMMCs and hCBMCs. Additionally, GMF overexpression in BMMCs obtained from wild-type mice released significantly more CCL2, while BMMCs obtained from GMF-deficient mice showed less CCL2 release. Further, we show that MPP(+)-induced CCL2 release was greater in BMMCs-astrocyte co-culture conditions. Uncoupling protein 4 (UCP4) which is implicated in neurodegenerative diseases including PD was detected in BMMCs by immunocytochemistry. Our results suggest that mast cells may play role in PD pathogenesis.

Dopaminergic Toxin 1-Methyl-4-Phenylpyridinium, Proteins α-Synuclein and Glia Maturation Factor Activate Mast Cells and Release Inflammatory Mediators.

Parkinson's disease (PD) is characterized by the presence of Lewy bodies and degeneration of dopaminergic neurons. 1-methyl-4-phenylpyridinium (MPP+), a metabolite of neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and Lewy body component α-synuclein activates glia in PD pathogenesis. Mast cells and glia maturation factor (GMF) are implicated in neuroinflammatory conditions including Multiple Sclerosis. However, the role of mast cells in PD is not yet known. We have analyzed the effect of recombinant GMF, MPP+, α-synuclein and interleukin-33 (IL-33) on mouse bone marrow-derived cultured mast cells (BMMCs), human umbilical cord blood-derived cultured mast cells (hCBMCs) and mouse brain-derived cultured astrocytes by quantifying cytokines/chemokines released using ELISA or by detecting the expression of co-stimulatory molecules CD40 and CD40L by flow cytometry. GMF significantly released chemokine (C-C motif) ligand 2 (CCL2) from BMMCs but its release was reduced in BMMCs from GMF knockout mice. GMF, α-synuclein and MPP+ released IL-1ß, ß-hexosaminidase from BMMCs, and IL-8 from hCBMCs. GMF released CCL5, and IL-33- induced the expression of GMF from hCBMCs. Novel GMF expression was detected in hCBMCs and BMMCs by immunocytochemistry. GMF released tumor necrosis factor-alpha (TNF-α) from mouse astrocytes, and this release was greater in BMMC- astrocyte coculture than in individual cultures. Flow cytometry results showed increased IL-33 expression by GMF and MPP+, and GMF-induced CD40 expression in astrocytes. Proinflammatory mediator release by GMF, MPP+ and α-synuclein, as well as GMF expression by mast cells indicate a potential therapeutic target for neurodegenerative diseases including PD.