Ncx3 gene ablation impairs oligodendrocyte precursor response and increases susceptibility to experimental autoimmune encephalomyelitis

Abstract

The Na(+) /Ca(2+) exchanger NCX3, recently identified as a myelin membrane component, is involved in the regulation of [Ca(2+) ]i during oligodendrocyte maturation. Here NCX3 involvement was studied in myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. Western blotting and quantitative colocalization studies performed in wild-type ncx3(+/+) mice at different stages of EAE disease showed that NCX3 protein was intensely upregulated during the chronic stage, where it was intensely coexpressed with the oligodendrocyte precursor cells (OPC) marker NG2 and the premyelinating marker CNPase. Moreover, MOG35-55 -immunized mice lacking the ncx3 gene displayed not only a reduced diameter of axons and an intact myelin ring number but also a dramatic decrease in OPC and pre-myelinating cells in the white matter of the spinal cord when compared with ncx3(+/+) . Accordingly, ncx3(-/-) and ncx3(+/-) mutants developed early onset of EAE and more severe clinical symptoms. Interestingly, cytofluorimetric analysis revealed that during the peak stage of the disease, the number of immune T-cell subsets in ncx3(-/-) mice, was not statistically different from that measured in ncx3(+/+) . Our findings demonstrate that knocking-out NCX3 impairs oligodendrocyte response and worsens clinical symptoms in EAE without altering the immune T-cell population. GLIA 2016;64:1124-1137.

EphB4 Regulates Self-Renewal, Proliferation and Neuronal Differentiation of Human Embryonic Neural Stem Cells in Vitro

“…Next, we analyzed the impact of EphB4 on glial differentiation. Immunostaining analysis and RT-PCR analysis of glial differentiation markers, GFAP for astrocytes and NG2 for early oligodendrocytes [33] revealed a significantly higher percentage of glial cells derived from hNSCs and a significantly higher of mRNA levels of GFAP and NG2 after EphB4 knockdown than from control hNSCs. Conversely, overexpression of EphB4 decreased the number of GFAP + and NG2 + cells and the mRNA levels of GFAP and NG2 (Fig.…”

Preconditioning, induced by sub-toxic dose of the neurotoxin L-BMAA, delays ALS progression in mice and prevents Na+/Ca2+ exchanger 3 downregulation

“…To date three different isoforms, NCX1-3, and several splicing variants have been described within the CNS. The specific role of each isoform in ALS pathophysiology has not yet been determined, nevertheless some seminal works attribute to NCX3 a pivotal role in neuromuscular transmission impairment 16 – 18 . These information render this transporter particularly interesting as putative druggable target in ALS.…”

Ionic Homeostasis Maintenance in ALS: Focus on New Therapeutic Targets

“…NCX, by contributing to the maintenance of Na + and Ca 2+ homeostasis, takes part to the progression of some neurological diseases including stroke, seizure, multiple sclerosis and Alzheimer Disease (Annunziato et al, 2004 , 2007 , 2013 ; Sirabella et al, 2009 ; Molinaro et al, 2011 , 2013 ; Pannaccione et al, 2012 ; Lanzillotta et al, 2013 ). Up to now, within the CNS, three different isoforms, NCX1, NCX2 and, NCX3, and numerous splicing variants have been identified; the precise involvement of each NCX isoform in ALS progression and etiology has not yet been determined, nonetheless some seminal works postulated a crucial role for NCX3 in mediating the impairment in neuromuscular transmission occurring ALS and in other related disease (Sokolow et al, 2004 ; Boscia et al, 2012 ; Casamassa et al, 2016 ; Anzilotti et al, 2018 ), thus rendering it a putative druggable target in ALS. On the other hand, as previously mentioned, In familiar ALS, mitochondrial Ca 2+ overload, caused by Cu/Zn-superoxide dismutase 1 (SOD1) mutation, causes strong ROS generation.…”