Proliferating culture of aged microglia for the study of neurodegenerative diseases.

Microglial cells' phenotype and function change with aging. Since microglial cell impairments that are relevant for neurodegenerative diseases appear to be unique to aged individuals, it is important to assess function of aged microglia. However, most studies are done with microglia from neonates, mostly due to lack of reliable protocols to obtain microglia from adult animals. Here, we present a conditioned media-dependent culture system that promotes proliferation of adult microglia. We observed that inflammatory activation was increasingly oxidative in microglia from aged animals. Also, whereas phagocytosis of Aβ by microglia from adult animals was more robust than that of microglia from neonates, the induction of phagocytosis by TGFβ was abolished in aged animals. Our results show the importance of using adult animals cells for the study of neurodegenerative processes or other diseases associated with aging. The proposed culture method is inexpensive and cell yield allows for their assessment by functional bioassays and biochemistry.