3.2.3 Reduced expression of TJ proteins
Using electron microscopic analysis, Garbuzova-Davis et al.suggested that the endothelial cell TJs appeared intact in early and
late symptomatic SOD1G93A mice (Garbuzova-Davis,
Haller, Saporta, Kolomey, Nicosia & Sanberg, 2007). However, using a
more quantitative approach (Western blot), a 30-60% reduction in zonula
occludens-1, occludin and claudin-5 was consistently observed in spinal
cord microvessels of SOD1G93A mice relative to
wildtype mice (Zhong et al., 2008). In addition, a progressive reduction
in occludin abundance at the BSCB in SOD1G93A mice was
demonstrated by Miyazaki et al. using immunohistochemistry and
Western blot (Miyazaki et al., 2011). Similarly, in
SOD1G93A rats, zonula occludens-1 and occludin mRNA
were significantly reduced in the lumbar spinal cords at the symptomatic
stage only but not in the brain or brain stem (Nicaise et al., 2009).