fumaric-acid and citraconic-acid

Dimethylfumarate (DMF) has been approved the for treatment of relapsing-remitting multiple sclerosis. The mode of action of DMF and its assumed active primary metabolite monomethylfumarate (MMF) is still not fully understood, notably for brain resident cells. Therefore we investigated potential direct effects of DMF and MMF on microglia and indirect effects on oligodendrocytes. Primary rat microglia were differentiated into M1-like, M2-like and M0 phenotypes and treated in vitro with DMF or MMF. The gene expression of pro-inflammatory and anti-inflammatory factors such as growth factors (IGF-1), interleukins (IL-10, IL-1β), chemokines (CCl3, CXCL-10) as well as cytokines (TGF-1β, TNFα), iNOS, and the mannose receptor (MRC1) was examined by determining their transcription level with qPCR, and on the protein level by ELISA and FACS analysis. Furthermore, microglia function was determined by phagocytosis assays and indirect effects on oligodendroglial proliferation and differentiation. DMF treatment of M0 and M1-like polarized microglia demonstrated an upregulation of gene expression for IGF-1 and MRC1, but not on the protein level. While the phagocytic activity remained unchanged, DMF and MMF treated microglia supernatants led to an enhanced proliferation of oligodendrocyte precursor cells (OPC). These results suggest that DMF has anti-inflammatory effects on microglia which may result in enhanced proliferation of OPC.

Topics: Animals; Cell Differentiation; Cell Proliferation; Dimethyl Fumarate; Fumarates; Gene Expression Regulation; Insulin-Like Growth Factor I; Maleates; Microglia; Neuroprotective Agents; Oligodendroglia; Phagocytosis; Rats, Sprague-Dawley; Stem Cells

A series of fumarate analogues has been used to explore the molecular mechanism of the activation of dopamine beta-mono-oxygenase by fumarate. Mesaconic acid (MA) and trans -glutaconic acid (TGA) both activate the enzyme at low concentrations, similar to fumarate. However, unlike fumarate, TGA and MA interact effectively with the oxidized enzyme to inhibit it at concentrations of 1-5 mM. Monoethylfumarate (EFum) does not activate the enzyme, but inhibits it. In contrast with TGA and MA, however, EFum inhibits the enzyme by interacting with the reduced form. The saturated dicarboxylic acid analogues, the geometric isomer and the diamide of fumaric acid do not either activate or inhibit the enzyme. The phenylethylamine-fumarate conjugate, N -(2-phenylethyl)fumaramide (PEA-Fum), is an approximately 600-fold more potent inhibitor than EFum and behaves as a bi-substrate inhibitor for the reduced enzyme. The amide of PEA-Fum behaves similarly, but with an inhibition potency approximately 20-fold less than that of PEA-Fum. The phenylethylamine conjugates of saturated or geometric isomers of fumarate do not inhibit the enzyme. Based on these findings and on steady-state kinetic analysis, an electrostatic model involving an interaction between the amine group of the enzyme-bound substrate and a carboxylate group of fumarate is proposed to account for enzyme activation by fumarate. Furthermore, in light of the recently proposed model for the similar copper enzyme, peptidylglycine alpha-hydroxylating mono-oxygenase, the above electrostatic model suggests that fumarate may also play a role in efficient electron transfer between the active-site copper centres of dopamine beta-mono-oxygenase.

Topics: Amides; Animals; Ascorbic Acid; Binding Sites; Cattle; Dopamine beta-Hydroxylase; Dose-Response Relationship, Drug; Electron Transport; Enzyme Activation; Fumarates; Glutarates; Kinetics; Maleates; Models, Chemical; Models, Molecular; Oxygen; Phenethylamines; Spectrophotometry; Tyramine

Systemic administration of fumaric acid (FA) derivatives was originally an empirical antipsoriatic treatment, which showed promising clinical results. In the present study, FURA-2-loaded suspensions of cultured normal keratinocytes and SV40-transformed keratinocytes (SVK-14 cells) were used to study the effects of FA derivatives on the intracellular free calcium concentration ([Ca2+]i). Monomethylfumarate (MMF), dimethylfumarate (DMF) and monoethylfumarate (MEF) induced a rapid, transient [Ca2+]i increase in both cell types. This immediate increase reached maximal values of 396 nmol/l 10s after addition of MMF, and fell to basal values within 90-120 s (173 nmol/l for normal keratinocytes and 68 nmol/l for transformed keratinocytes). This increase was not affected by the prior addition of EGTA, indicating that FA derivatives released Ca2+ mainly from intracellular stores into the cytoplasm. Subsequently, dose-dependent inhibitory effects of FA derivatives on keratinocyte proliferation were demonstrated. The results of these experiments revealed that DMF was the most potent, MMF and MEF intermediate, and FA and malonic acid the least potent growth inhibitors. These antiproliferative effects of FA derivatives might be linked to the observed, transient [Ca2+]i elevations.

Topics: Anticarcinogenic Agents; Calcium; Cell Division; Cell Line, Transformed; Cells, Cultured; Depression, Chemical; Dimethyl Fumarate; Dose-Response Relationship, Drug; Fumarates; Humans; Intracellular Fluid; Keratinocytes; L-Lactate Dehydrogenase; Male; Maleates

Topics: Anthracenes; Citraconic Anhydrides; Fumarates; Maleates

Topics: Citraconic Anhydrides; Fumarates; Maleates