Blood-Brain Barrier Alterations in the Cerebral Cortex in Experimental Autoimmune Encephalomyelitis

作者：Errede Mariella^*; Girolamo Francesco; Ferrara Giovanni; Strippoli Maurizio; Morando Sara; Boldrin Valentina; Rizzi Marco; Uccelli Antonio; Perris Roberto; Bendotti Caterina; Salmona Mario; Roncali Luisa; Virgintino Daniela

来源：Journal of Neuropathology and Experimental Neurology, 2012, 71(10): 840-854.

DOI：10.1097/NEN.0b013e31826ac110

• Blood-brain barrier
• Cerebral cortex demyelination
• Claudin-5
• Experimental autoimmune encephalomyelitis
• Inflammation
• Occludin
• Oligodendrocyte precursor cells

The pathophysiology of cerebral cortical lesions in multiple sclerosis (MS) is not understood. We investigated cerebral cortex microvessels during immune-mediated demyelination in the MS model chronic murine experimental autoimmune encephalomyelitis (EAE) by immunolocalization of the endothelial cell tight junction (TJ) integral proteins claudin-5 and occludin, a structural protein of caveolae, caveolin-1, and the blood-brain barrier-specific endothelial transporter, Glut 1. In EAE-affected mice, there were areas of extensive subpial demyelination and well-demarcated lesions that extended to deeper cortical layers. Activation of microglia and absence of perivascular inflammatory infiltrates were common in these areas. Microvascular endothelial cells showed increased expression of caveolin-1 and a coincident loss of both claudin-5 and occludin normal junctional staining patterns. At a very early disease stage, claudin-5 molecules tended to cluster and form vacuoles that were also Glut 1 positive; the initially preserved occludin pattern became diffusely cytoplasmic at more advanced stages. Possible internalization of claudin-5 on TJ dismantling was suggested by its coexpression with the autophagosomal marker MAP1LC3A. Loss of TJ integrity was confirmed by fluorescein isothiocyanate-dextran experiments that showed leakage of the tracer into the perivascular neuropil. These observations indicate that, in the cerebral cortex of EAE-affected mice, there is a microvascular disease that differentially targets claudin-5 and occludin during ongoing demyelination despite only minimal inflammation.

• 出版日期2012-10