Aluminum inhibition of microglial function in vitro

We have previously observed in vivo that chronic AlCl3 exposure in young adult New Zealand white rabbits induces a reversible motor neuron degeneration. In addition to the development of neurofilamentous aggregates within degenerating neurons, we have also observed a reduction of microglial number and activation. To determine if aluminum could directly effect microglial function in vivo, we used an immortalized murine microglial cell line (BV-2) to study the effect of organic (aluminum lactate) and inorganic (AlCl3) compounds on microglial function. We have observed a dose-dependent inhibition of phagocytosis, proliferation, migration, and release of TNF-α and nitric oxide in the absence of inducing microglial death. Both organic and inorganic aluminum decreased the extent of LPS-activated microglia-mediated death of a motor neuron hybridoma cell line (NSC 34). These findings demonstrate that aluminum compounds can directly affect microglial in vitro. J. Trace Elem. Exp. Med. 15:141–152, 2002. © 2002 Wiley-Liss, Inc.