Investigation of cytokine changes and deiminated proteins in LPS-induced inflammation in BV2 microglial cells

Abstract

Abstract Background Recent studies show that, deimination, one of the post-translational modifications, is associated with the neuro-degenerative disease process. Peptidyl arginine deiminases (PADs) catalyze deimination, PAD2 is particularly active in the central nervous system. This study aimed to examine the changes in proteins regarding deimination by inducing inflammation with lipopolysaccharide (LPS) in the BV2 microglial cell line and observe the changes in cytokines. Methods LPS was applied to the microglial cell line. The change in Interleukin-1β (IL-1β) was observed by enzyme linked immunosorbent assay (ELISA). Western blotting with F95 antibody was performed to identify deimine proteins. To determine whether C-reactive protein (CRP) was changed, immunoprecipitation with anti-CRP antibody or not was followed by western blotting with F95 antibody. Real-time polymerase chain reaction (RT-PCR) was performed to determine the change in PAD2 and CRP expression levels. Results A significant increase in IL-1β due to inflammation was observed in microglia. An increase in the proteins subjected to deimination was observed by Western blot method and it was determined that CRP was deiminated. A statistically significant decrease in PAD2 expression level was observed by RT-PCR. Conclusions In the present study, an increase in IL 1-β levels and the amount of deimination protein was observed as a result of inflammation.This result confirms that there is a connection between neurodegeneration and deimination. This study is the first to show that CRP is one of the deiminated protein candidates as a result of inflammation in microglia.