Enhanced sphingosine-1-phosphate receptor 2 expression underlies female CNS autoimmunity susceptibility
Lillian Cruz-Orengo, … , Seth D. Crosby, Robyn S. Klein
Lillian Cruz-Orengo, … , Seth D. Crosby, Robyn S. Klein
Published May 8, 2014
Citation Information: J Clin Invest. 2014;124(6):2571-2584. https://doi.org/10.1172/JCI73408.
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Research Article Autoimmunity

Enhanced sphingosine-1-phosphate receptor 2 expression underlies female CNS autoimmunity susceptibility

Abstract

Multiple sclerosis (MS) is an inflammatory disease of the CNS that is characterized by BBB dysfunction and has a much higher incidence in females. Compared with other strains of mice, EAE in the SJL mouse strain models multiple features of MS, including an enhanced sensitivity of female mice to disease; however, the molecular mechanisms that underlie the sex- and strain-dependent differences in disease susceptibility have not been described. We identified sphingosine-1-phosphate receptor 2 (S1PR2) as a sex- and strain-specific, disease-modifying molecule that regulates BBB permeability by destabilizing adherens junctions. S1PR2 expression was increased in disease-susceptible regions of the CNS of both female SJL EAE mice and female patients with MS compared with their male counterparts. Pharmacological blockade or lack of S1PR2 signaling decreased EAE disease severity as the result of enhanced endothelial barrier function. Enhanced S1PR2 signaling in an in vitro BBB model altered adherens junction formation via activation of Rho/ROCK, CDC42, and caveolin endocytosis-dependent pathways, resulting in loss of apicobasal polarity and relocation of abluminal CXCL12 to vessel lumina. Furthermore, S1PR2-dependent BBB disruption and CXCL12 relocation were observed in vivo. These results identify a link between S1PR2 signaling and BBB polarity and implicate S1PR2 in sex-specific patterns of disease during CNS autoimmunity.

Authors

Lillian Cruz-Orengo, Brian P. Daniels, Denise Dorsey, Sarah Alison Basak, José G. Grajales-Reyes, Erin E. McCandless, Laura Piccio, Robert E. Schmidt, Anne H. Cross, Seth D. Crosby, Robyn S. Klein

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Figure 3

Female SJL mice exhibit sexually dimorphic enhancement of BBB permeability and S1PR2 expression during EAE.

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Female SJL mice exhibit sexually dimorphic enhancement of BBB permeabili...
(A) Male and female C57BL/6 and SJL mice at peak of EAE (clinical score of 3 to 4) or first remission (clinical score of 2) were examined for BBB permeability to Na-Fluorescein within cortices, cerebella, and spinal cords, normalized to sera values for individual mice (5–8 mice per group). Data are reported as arbitrary fluorescence values, normalized to mean values for naive male C57BL/6 in each CNS region. (B) Protein lysates from CNS regions of male and female C57BL/6 and SJL mice at peak of EAE (clinical scores of 3 to 4) were probed for S1PR2 (red), with β-tubulin (green) as a loading control. Data are reported as density values of S1PR2 normalized to density values for β-tubulin. Data are normalized to mean values for male C57BL/6 mice in each CNS region. (A and B) Bar graphs depict mean ± SEM findings for male (B6: light blue bars; SJL: blue bars) and female (B6: light red bars; SJL: red bars) for 4 mice per group. *P < 0.05; ***P < 0.001, 2-way ANOVA. (C) Immunofluorescence detection of S1PR2 (red, top and middle; green, bottom) in vessels (CD31, green), astrocytes (GFAP, green), and pericytes (PDGF-Rβ, red, bottom) in cortices, cerebella, and spinal cords of female SJL mice at peak of EAE. All nuclei were stained with Topro3 (blue). Scale bar: 25 μm. Data are representative of 10 images each from 5 male and 5 female animals. Arrows indicate areas of colocalization.