oxadiazoles and Demyelinating-Diseases

Multiple sclerosis (MS) is the most common chronic inflammatory, demyelinating and neurodegenerative disease of the central nervous system in young adults. This disorder is a heterogeneous, multifactorial, immune-mediated disease that is influenced by both genetic and environmental factors. In most patients, reversible episodes of neurological dysfunction lasting several days or weeks characterize the initial stages of the disease (that is, clinically isolated syndrome and relapsing-remitting MS). Over time, irreversible clinical and cognitive deficits develop. A minority of patients have a progressive disease course from the onset. The pathological hallmark of MS is the formation of demyelinating lesions in the brain and spinal cord, which can be associated with neuro-axonal damage. Focal lesions are thought to be caused by the infiltration of immune cells, including T cells, B cells and myeloid cells, into the central nervous system parenchyma, with associated injury. MS is associated with a substantial burden on society owing to the high cost of the available treatments and poorer employment prospects and job retention for patients and their caregivers.

Topics: Azetidines; Benzyl Compounds; Demyelinating Diseases; Humans; Indans; Magnetic Resonance Imaging; Multiple Sclerosis; Oxadiazoles; Risk Factors; Thiazoles; Tomography, X-Ray Computed

Maintaining the normal function of oligodendrocyte precursor cells (OPCs) and protecting OPCs from damage is the basis of myelin regeneration in multiple sclerosis (MS). In this paper, we investigated the effect of stemazole, a novel small molecule, on the promotion of oligodendrocyte precursor cell survival and remyelination. The results show that stemazole enhanced the survival rate and the number of clone formation in a dose-dependent manner and decreased the percentage of cell apoptosis. In particular, the number of cell clones was increased up to 6-fold (p < 0.001) in the stemazole group compared with the control group. In vivo, we assessed the effect of stemazole on recovering the motor dysfunction and demyelination induced by cuprizone (CPZ). The results show that stemazole promoted the recovery of motor dysfunction and the repair of myelin sheaths. Compared with the CPZ group, the stemazole group showed a 30.46% increase in the myelin area (p < 0.001), a 37.08% increase in MBP expression (p < 0.01), and a 1.66-fold increase in Olig2 expression (p < 0.001). Histologically, stemazole had a better effect than the positive control drugs. In conclusion, stemazole promoted OPC survival in vitro and remyelination in vivo, suggesting that this compound may be used as a therapeutic agent against demyelinating disease.

Topics: Animals; Cell Differentiation; Cuprizone; Demyelinating Diseases; Disease Models, Animal; Hydrazines; Mice; Mice, Inbred C57BL; Myelin Sheath; Oligodendrocyte Precursor Cells; Oligodendroglia; Oxadiazoles; Remyelination

Recent evidence suggests that the oral drug Fingolimod (FTY720) for relapsing-remitting multiple sclerosis (MS) may act directly on the central nervous system (CNS) and modulate disease pathogenesis and progression in experimental models of MS. However, the specific subtype of sphingosine-1-phosphate (S1P) receptors that mediates the effect of FTY720 on the CNS cells has not been fully elucidated. Here, we report that S1P receptor 1 (S1PR1) is elevated in reactive astrocytes in an autoimmunity independent mouse model of MS and that selective S1PR1 modulation is sufficient to ameliorate the loss of oligodendrocytes and demyelination. The non-selective S1PR modulator, FTY720, or a short-lived S1PR1-specific modulator, CYM5442, was administered daily to mice while on cuprizone diet. Both FTY720- and CYM5422-treated mice displayed a significant reduction in oligodendrocyte apoptosis and astrocyte and microglial activation in comparison to vehicle-treated groups, which was associated with decreased production of proinflammatory mediators and down-regulation of astrocytic S1PR1 protein. Interestingly, S1PR1 modulation during the early phase of cuprizone intoxication was required to suppress oligodendrocyte death and consequent demyelination as drug treatment from 10 days after the initiation of cuprizone feeding was no longer effective. CYM5442 treatment during the brief cuprizone exposure significantly prevented Il-1β, Il-6, Cxcl10, and Cxcl3 induction, resulting in suppression of subsequent reactive gliosis and demyelination. Our study identifies functional antagonism of S1PR1 as a major mechanism for the protective effect of FTY720 in the cuprizone model and suggests pathogenic contributions of astrocyte S1PR1 signaling in primary demyelination and its potential as a therapeutic target for CNS inflammation.

Topics: Animals; Apoptosis; Brain; Chimera; Cuprizone; Demyelinating Diseases; Disease Models, Animal; Fingolimod Hydrochloride; Gene Expression; Gliosis; Indans; Inflammation; Male; Mice, Inbred C57BL; Mice, Transgenic; Neuroglia; Neuroprotective Agents; Oxadiazoles; Receptors, Lysosphingolipid; Sphingosine-1-Phosphate Receptors; White Matter

BAF312 (Siponimod) is a dual agonist at the sphingosine-1 phosphate receptors, S1PR1 and S1PR5. This drug is currently undergoing clinical trials for the treatment of secondary progressive multiple sclerosis (MS). Here, we investigated the effects of BAF312 on isolated astrocyte and microglia cultures as well as in slice culture models of demyelination.. Mouse and human astrocytes were treated with S1PR modulators and changes in the levels of pERK, pAkt, and calcium signalling as well as S1PR1 internalization and cytokine levels was investigated using Western blotting, immunochemistry, ELISA and confocal microscopy. Organotypic slice cultures were prepared from the cerebellum of 10-day-old mice and treated with lysophosphatidylcholine (LPC), psychosine and/or S1PR modulators, and changes in myelination states were measured by fluorescence of myelin basic protein and neurofilament H.. BAF312 treatment of human and mouse astrocytes activated pERK, pAKT and Ca(2+) signalling as well as inducing S1PR1 internalization. Notably, activation of S1PR1 increased pERK and pAKT in mouse astrocytes while both S1PR1 and S1PR3 equally increased pERK and pAKT in human astrocytes, suggesting that the coupling of S1PR1 and S1PR3 to pERK and pAKT differ in mouse and human astrocytes. We also observed that BAF312 moderately attenuated lipopolysaccharide (LPS)- or TNFα/IL17-induced levels of IL6 in both astrocyte and microglia cell cultures. In organotypic slice cultures, BAF312 reduced LPC-induced levels of IL6 and attenuated LPC-mediated demyelination. We have shown previously that the toxic lipid metabolite psychosine induces demyelination in organotypic slice cultures, without altering the levels of cytokines, such as IL6. Importantly, psychosine-induced demyelination was also attenuated by BAF312.. Overall, this study suggests that BAF312 can modulate glial cell function and attenuate demyelination, highlighting this drug as a further potential therapy in demyelinating disorders, beyond MS.

Topics: Animals; Animals, Newborn; Anti-Inflammatory Agents; Astrocytes; Azetidines; Benzyl Compounds; beta-Alanine; Calcium Signaling; Cerebellum; Demyelinating Diseases; eIF-2 Kinase; Humans; Immunosuppressive Agents; In Vitro Techniques; Indans; Interleukin-6; Lysophosphatidylcholines; Mice; Myelin Basic Protein; Organ Culture Techniques; Oxadiazoles; Protein Transport; Receptors, Lysosphingolipid; Thiophenes; Time Factors

Sphingosine-1-phosphate receptors (S1PRs) are drug targets for the compound FTY720, which is the first oral therapy developed for treatment of relapsing-remitting multiple sclerosis. S1PRs play a variety of functional roles in the differentiation, proliferation, survival and/or migration of neurons and glia. In this study, rat organotypic cerebellar slice cultures were used to assess whether S1PRs play a role in demyelination induced by lysolecithin (LPC). The data demonstrated that FTY720 and SEW2871 (a S1P1R-specific agonist) inhibited LPC-induced demyelination as assessed by myelin basic protein (MBP) immunofluorescence. Treatment with both drugs for 48 h also induced an increase in S1P1R expression in astrocytes. Moreover, FTY720 and SEW2871 inhibited the release of several chemokines in conditions of LPC-induced demyelination, including LIX (CXCL5), MIP-1alpha, and MIP-3alpha. Taken together, the data suggest that activation of S1P1Rs prevents LPC-induced demyelination via a mechanism involving a reduction of chemotactic chemokine release. The study supports the concept that FTY720 attenuates demyelination by not only preventing S1PR-mediated T cell migration into the CNS but also by limiting cytokine communication between cells of the immune system and the CNS.

Topics: Animals; Animals, Newborn; Astrocytes; Cell Movement; Cerebellum; Chemokine CCL20; Chemokine CCL3; Chemokines; Demyelinating Diseases; Fingolimod Hydrochloride; Gene Expression Regulation; Immunosuppressive Agents; Lysophosphatidylcholines; Myelin Basic Protein; Neurofilament Proteins; Organ Culture Techniques; Oxadiazoles; Propylene Glycols; Rats; Rats, Wistar; Receptors, Lysosphingolipid; Sphingosine; Thiophenes