Microglial Sp1 induced LRRK2 upregulation in response to manganese exposure, and 17β-estradiol afforded protection against this manganese toxicity. (PubMed, Neurotoxicology)
The results showed that Mn induced cytotoxicity, oxidative stress, and tumor necrosis factor-α production, which were attenuated by an LRRK2 inhibitor, GSK2578215A...Furthermore, E2 attenuated the Mn-induced Sp1 expression by decreasing the expression of Sp1 via the promotion of the ubiquitin-dependent degradation pathway, which was accompanied by increased protein levels of RING finger protein 4, the E3-ligase of Sp1, Sp1 ubiquitination, and SUMOylation. Taken together, our novel findings suggest that Sp1 serves as a critical TF in Mn-induced LRRK2 expression as well as in the protection afforded by E2 against Mn toxicity through reduction of LRRK2 expression in microglia.