Caveolae, CD109, and endothelial cells as targets for treating Alzheimer's disease

Reduced functionality of transforming growth factor β (TGF‐β) is a major pathogenetic component of Alzheimer's disease (AD). The reduction is caused by an ≈50% decrease in the AD brain of the TGF‐β receptor, TGFBR, causing a bottleneck effect that reduces the downstream actions of TGF‐β, which is highly disadvantageous for brain function. Degradation of TGFBR occurs in caveolae with participation by caveolin‐1 (Cav‐1) and CD109. Mechanisms for this are discussed. In the cerebral microcirculation, endothelial cells (which are rich in caveolae) carry CD109 as a surface marker that co‐precipitates with Cav‐1. Atorvastatin reduced Cav‐1 by 75% and, because Cav‐1 and CD109 co‐immunoprecipitate reciprocally, atorvastatin would also reduce the level of CD109. Administration of atorvastatin as a component of combination therapy would diminish the degradation of TGFBR and thereby benefit patients with AD.