ABSTRACT
Inflammation, demyelination, oligodendrocyte (OLG) death, and axonal degeneration are primary characteristics of multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE). OLGs generate myelin sheaths that surround axons, while damage to OLGs leads to demyelination and neurological functional deficit. Matrine (MAT), a quinolizidine alkaloid derived from the herb Radix Sophorae Flave, has been recently found to effectively ameliorate clinical signs in EAE. Its therapeutic mechanism has, however, not been completely elucidated. In the present study, we found that MAT retarded the disease process, attenuated the clinical severity of EAE rats, ameliorated inflammation and demyelination, and suppressed the apoptosis of OLGs in the central nervous system (CNS) of EAE rats. In addition, MAT markedly blocked increased expression of the proNGF-p75(NTR) death signaling complex, which is known to mediate OLG death in EAE animals. At the same time, MAT also prevented a decrease in the levels of NGF and its receptor TrkA, which together mediate the cell survival pathway and differentiation of OLGs. ProNGF, NGF, and the downstream effector proteins play an important role in the growth, differentiation, and apoptosis of OLGs as well as the reparative response to neuronal damage. These findings thus indicate that MAT improves clinical severity of EAE in part by reducing OLG apoptosis via restoring the ratios of proNGF:NGF and the respective receptors p75(NTR):TrkA in vivo. Taken together, these results suggest that MAT may be a promising agent for MS treatment based on its protective effect on OLGs.
Subject(s)
Alkaloids/pharmacology , Encephalomyelitis, Autoimmune, Experimental/prevention & control , Nerve Growth Factors/metabolism , Protein Precursors/metabolism , Quinolizines/pharmacology , Signal Transduction/drug effects , Animals , Apoptosis/drug effects , Axons/drug effects , Cell Survival/drug effects , Central Nervous System/drug effects , Central Nervous System/metabolism , Central Nervous System/pathology , Demyelinating Diseases/metabolism , Demyelinating Diseases/prevention & control , Encephalomyelitis, Autoimmune, Experimental/metabolism , Female , Fluorescent Antibody Technique , Immunohistochemistry , Neuroprotective Agents/pharmacology , Oligodendroglia/drug effects , Oligodendroglia/metabolism , Oligodendroglia/pathology , Phytotherapy/methods , Rats, Wistar , Sophora/chemistry , MatrinesABSTRACT
Multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE), are autoimmune diseases characterized by immune-mediated neuroinflammation, demyelination and neurodegeneration of the central nervous system (CNS). While matrine (MAT), a monomer that is used in traditional Chinese medicine as an anti-inflammatory treatment, delayed onset and ameliorated severity of EAE, the underlying mechanisms have not been fully elucidated. In this study, we investigated the relationship between the clinical effect of MAT and the levels of certain important chemokines/chemokine receptors. Our results showed that attenuated severity of EAE resulting from MAT treatment was positively correlated with the reduction of CCL2 and CXCL10 levels in the periphery and the CNS; both of these chemokines play a crucial role in the recruitment and accumulation of inflammatory cells, especially monocytes/macrophages and T cells, into the CNS. The levels of their corresponding receptors, CCR2 and CXCR3, were also significantly reduced after MAT treatment. Taken together, our data indicate that MAT may be an effective immunomodulatory therapeutic approach for MS/EAE by countering the immune cell recruitment mechanisms.
