Electronic Poster | Session 1

047 – Agathisflavone (FAB) acts via alpha estrogen receptors to promote remyelination and regulate gliosis in the mouse cerebellar slice lysolecithin demyelination model

MONIQUE MARYLIN ALVES DE ALMEIDA (1, 4) – FRANCESCA PIEROPAN (4) – Larissa de Matos Oliveira (5) – Jorge Mauricio David (2) – Juceni Pereira David (3) – Manoelito Coelho dos Santos Junior (5) – Victor Diogenes A. da Silva (1) – Cleide dos Santos Souza (6) – Silvia Lima Costa (1*) – Arthur Morgan Butt (4*)
Department of Biochemistry and Biophysics, Institute of Health Sciences, Federal University of Bahia, Brazil (1) – Departament of Inorganic Chemistry, Institute of Chemistry, Federal University da Bahia, Brazil (2) – Departament of Medication, Faculty of Pharmacy, Federal University of Bahia, Brazil (3) – School of Pharmacy and Biomedical Science, University of Portsmouth, United Kingdom (4) – Department of Health, State University of Feira de Santana, Brazil (5) – Department of Chemistry, University of Sheffield, United Kingdom (6)

Estrogen receptors (ER) are important pharmacological targets to induce remyelination. Here, we have examined the effect of the phytoestrogen agathisflavone (FAB) on demyelination and neuroinflammation, which are hallmarks of Multiple Sclerosis (MS) and is important in most neuropathologies. Cerebellar slices from Sox10-EGFP reporter mice aged postnatal day (P)10-12 were maintained for 7 days in vitro (DIV). Demyelination was induced by lysolecithin (LPC, 0.5mg/mL), followed by treatment with agathisflavone (5 or 10µM) for 2DIV and analysed by immunohistochemistry (IHC). Demyelination (MBP-IHC) and axonal degeneration (NF-IHC) were prominent following LPC treatment, compared to controls, whilst FAB significantly accelerated remyelination and protected against axonal damage, as well as protecting Purkinje neurons against apoptosis mediated death (Calbindin+/Caspase 3 cleaved+). Treatment with FAB significantly increased the number of NG2+ oligodendrocytes precursor cells (OPCs) and stimulated their proliferation (SOX10+/Ki67+), as well as increasing the number of mature oligodendrocytes (CC1+), and decreasing their apoptosis mediated death (CC1+/Caspase 3 cleaved+). Furthermore, LCT induced astrogliosis (GFAP-IHC) and microglial proliferation (IBA1+/Ki67+), as well as switching microglia phenotype from predominantly M1 to M2 (ratio of CD16/32+/CD206+), and this was reverted by FAB. RT-qPCR showed that FAB reduces Tnfa, Il1β, and Nos2 and increases Arg1, Tgfb and Acvr1b expression. Notably, the promyelinating and antigliotic effects of FAB were inhibited by blockade of alpha estrogen receptors (aER), and molecular docking analyses demonstrated intermolecular interactions between FAB and aER, which has known promyelinating and prosurvival effects. This study provides evidence that FAB acts via aER to promote oligodendrocyte regeneration and remyelination and switches microglia to a phenotype that is beneficial for repair. The results indicate FAB may constitute a promising non-toxic disease-modifying therapy in MS and other neuropathologies.
Keywords: Flavonoids, Remyelination, Microglia, Estrogen Receptors.