Cytoplasmic gelsolin in pheochromocytoma-12 cells forms a complex with amyloid beta-protein

Gelsolin exists as secretory (plasma) and cytoplasmic forms. We have reported that plasma gelsolin binds to amyloid beta-protein (Abeta), and inhibits its fibrillization. Others reported that peripheral administration or transgene expression of plasma gelsolin reduces amyloid load in transgenic mouse models of Alzheimer's disease. Here, we report that the expression of cytoplasmic gelsolin in pheochromocytoma-12 cells increases after treatment with hydrogen peroxide. When synthetic Abeta was fortified with cell lysate, cytoplasmic gelsolin co-immunoprecipitated with Abeta. The results suggest that cytoplasmic gelsolin forms a complex with Abeta in a manner like plasma form, and it may also regulate Abeta fibrillization. This report indicates that structural differences between plasma and cytoplasmic gelsolin do not play a key role in their complex formation with Abeta.