INTERCELLULAR INTERACTIONS IN PC12 CELLS OVEREXPRESSING BETA/A4 AMYLOID

The amyloid precursor protein (APP) is an integral membrane component of eukaryotic cells. A variety of research approaches have addressed the contribution of the beta amyloid peptide region of the APP to neuritic plaque structure and formation in the Alzheimer disease brain as well as the relationship between beta amyloid accumulation and the occurrence of dementia. However, there is limited information available concerning the cellular consequences of amyloid deposition. The present studies were undertaken to investigate the relationship between beta amyloid and intercellular junctions. Transfected PC12 eel lines, that overexpress the beta amyloid peptide, exhibit structural and functional alterations at the cell surface and tend to form aggregates more readily than normal control cells. Intermediate junctions were the most common intercellular interactions of both normal and transfected cells. However, the control and transfected cells differed since areas of continuous and extensive junctions were readily seen in transfected cells and infrequently seen in control cells. The data suggest that excess accumulation of beta amyloid is associated with the junctional apparatus and may be related to increased intercellular adhesion.