ABSTRACT
Multiple sclerosis (MS) is an intractable disease of the central nervous system that results from destruction of the myelin sheath. Direct measurement of de- and remyelination is required for monitoring the disease stage of MS, but no useful method has been established. In this study, we characterized four diaryl oxadiazole derivatives as novel myelin-imaging probes for single photon emission computed tomography (SPECT). All the diaryl oxadiazole derivatives penetrated the blood-brain barrier in normal mice. Among them, the highest ratio of radioactivity accumulation in the white matter (myelin-rich region) against the gray matter (myelin-deficient region) was observed at 60 min postinjection of [125I]1,3,4-PODP-DM in ex vivo autoradiography using normal mice. In the blocking study with ex vivo autoradiography, the radioactivity accumulation of [125I]1,3,4-PODP-DM in the white matter markedly reduced. [125I]1,3,4-PODP-DM detected demyelination in the ex vivo autoradiographic images of not only the spinal cord of the experimental autoimmune encephalomyelitis mice but also the brain after lysophosphatidylcholine (LPC) injection. In addition, [123I]1,3,4-PODP-DM could image LPC-induced demyelination in the mouse brain with SPECT. These results suggest that [123I]1,3,4-PODP-DM may be a potential SPECT probe for imaging myelin in MS.
Subject(s)
Encephalomyelitis, Autoimmune, Experimental , Multiple Sclerosis , Animals , Encephalomyelitis, Autoimmune, Experimental/diagnostic imaging , Mice , Multiple Sclerosis/diagnostic imaging , Myelin Sheath , Oxadiazoles/pharmacology , Tomography, Emission-Computed, Single-PhotonABSTRACT
Multiple sclerosis (MS) is the common demyelinating disease of human central nervous system. Among mouse models available to study MS, including the cuprizone application and lysolecithin-injection models, experimental autoimmune encephalomyelitis (EAE) model is widely used so that chronic EAE model of C57BL/6J can reflect the autoimmune pathogenesis of MS well. Here we introduce the EAE model based on C57BL/6J mice, which is generated by injection of myelin oligodendrocyte glycoprotein 35-55 (MOG 35-55) as an antigen. After immunization with complete Freund's adjuvant, clinical signs and changes in body weight are observed one or two weeks later. The EAE model will continue to be useful for development of therapeutics for MS.
