Lipoprotein receptor-related protein-1 (LRP-1), a multifunctional scavenger and signaling receptor, is expressed in neural cells and cerebral microvessels including capillaries, small venules, and arterioles (Wolf et al., 1992; Tooyama et al., 1995; Shibata et al., 2000). LRP-1 has received increasing attention as it mediates transport of Aβ out of the brain across the BBB (Bell and Zlokovic, 2009). Many reports have described the genetic linkage of LRP-1 with AD (Kang et al., 1997; Lambert et al., 1998; Wavrant-DeVrièze et al., 1999) and CAA (Christoforidis et al., 2005). Colocalization of LRP-1 with Aβ was pathologically recognized in senile plaques (Rebeck et al., 1993; Donahue et al., 2006), strengthening the linkage. The relationship is further supported by reduced LRP-1 staining in vessels both in AD patients (Shibata et al., 2000; Donahue et al., 2006) and CAA model mice carrying a vasculotropic Dutch/Iowa mutant form of APP gene (Deane et al., 2004).
