Effects of AgNP Exposure on F-actin Organization and Tau Protein Localization Using Caenorhabditis Elegans

Due to their strong antimicrobial properties, AgNPs are increasingly incorporated into consumer and medical products. AgNPs shed off these products, can be ingested, inhaled, and cross the blood-brain barrier, leading to bioaccumulation in the brain. We previously found that AgNP exposure disrupts F-actin organization and induces neurite collapse in cultured neural cells. The nematode Caenorhabditis elegans has a well characterized nervous system and is easily genetically modified, making it well suited to study the structure of neurons. We examined how AgNP exposure during development impacts the morphology of F-actin dependent structures, such as dendritic branches. Following AgNP exposure, an increase in quaternary dendritic structures within the PVD neuron was observed. We also examined AgNP exposure effects on the localization of human tau protein in cell body versus neuronal processes during aging. Worms expressing aggregation prone human tau appear to increase tau localization to neuronal processes and not cell bodies following AgNP exposure. AgNP exposure may alter dendritic structure and tau localization mechanisms in neurons. This work will help to understand the effects of AgNP exposure on brain function and inform regulation of the manufacture and disposal of products containing this material. This work is supported by NSF CBET #2413997 to NS. KB received a SURE fellowship.