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 t he contribution of the beta amyloid peptide region of the APP to neuri tic plaque structure and formation in the Alzheimer disease brain as w ell as the relationship between beta amyloid accumulation and the occu rrence of dementia. However, there is limited information available co ncerning the cellular consequences of amyloid deposition. The present studies were undertaken to investigate the relationship between beta a myloid and intercellular junctions. Transfected PC12 eel lines, that o verexpress the beta amyloid peptide, exhibit structural and functional alterations at the cell surface and tend to form aggregates more read ily than normal control cells. Intermediate junctions were the most co mmon intercellular interactions of both normal and transfected cells. However, the control and transfected cells differed since areas of con tinuous 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 apparat us and may be related to increased intercellular adhesion.