Two actin binding proteins, actin depolymerizing factor and cofilin, are associated with Hirano bodies.

Hirano bodies are intracellular, paracrystalline, rod-like structures which contain actin, tropomyosin, vinculin, alpha-actinin, amyloid beta-protein precursor and several microtubule associated proteins (MAPs). These bodies are observed more frequently in the elderly and in a number of neurodegenerative diseases including Alzheimer's disease. Many of the proteins known to be associated with Hirano bodies are actin binding proteins. We present immunohistological evidence that actin depolymerizing factor (ADF) and cofilin, two closely related proteins that bind and sever actin filaments, are also components of Hirano bodies. However, we could detect no difference in the levels of expression of either ADF or cofilin in the hippocampal tissue from normal individuals and Alzheimer's disease patients.