Fumaric Acids Directly Influence Gene Expression of Neuroprotective Factors in Rodent Microglia

Area of Science:

• Neuroimmunology
• Cell Biology
• Pharmacology

Background:

• Dimethyl fumarate (DMF) is an approved treatment for relapsing-remitting multiple sclerosis.
• The precise mechanism of action for DMF and its metabolite monomethyl fumarate (MMF) in the central nervous system, particularly on glial cells, remains unclear.
• Understanding DMF's effects on microglia and oligodendrocytes is crucial for optimizing multiple sclerosis therapy.

Purpose of the Study:

• To investigate the direct effects of DMF and MMF on primary rat microglia.
• To examine the indirect impact of DMF and MMF on oligodendrocyte precursor cells (OPCs).
• To elucidate the anti-inflammatory and neuroprotective potential of DMF in the context of multiple sclerosis.

Main Methods:

• Primary rat microglia were differentiated into M0, M1-like, and M2-like phenotypes and treated with DMF or MMF in vitro.
• Gene and protein expression of inflammatory markers (e.g., IL-10, TNFα, iNOS) and growth factors (IGF-1) were analyzed using qPCR, ELISA, and FACS.
• Microglia phagocytic activity was assessed, and conditioned media effects on OPC proliferation and differentiation were evaluated.

Main Results:

• DMF treatment upregulated gene expression of IGF-1 and Mannose Receptor C (MRC1) in M0 and M1-like microglia, but not at the protein level.
• Microglial phagocytic activity was not significantly altered by DMF or MMF treatment.
• Supernatants from DMF- and MMF-treated microglia enhanced the proliferation of oligodendrocyte precursor cells (OPCs).

Conclusions:

• Dimethyl fumarate exhibits anti-inflammatory properties in microglia.
• DMF and MMF may indirectly promote oligodendrocyte precursor cell proliferation.
• These findings suggest a potential therapeutic pathway for DMF in multiple sclerosis via microglial modulation and oligodendrocyte support.