Only IL4 treated microglia were Bosutinib molecular weight compared with controls because LPS treated cells migrated very poorly. IL4 treatment greatly in creased transmigration, and this was reduced back to the control level by the Cat S inhibitor. The apparent trend toward reduced transmigration by three other inhibitors did not reach statistical significance with the sample size used. None of the inhibitors affected cell viability at the concentrations and times tested. Interestingly, invasion through the same ECM sub strate required different enzymes in un treated and IL4 treated microglia. In unstimulated microglia, invasion was inhibited only by the broad spectrum cysteine cathepsin inhibitor, E 64, which decreased invasion to approximately 50% below the control level.

Inhibitors,Modulators,Libraries Invasion was not altered by the selective Cat S and K inhibitors, suggesting that E 64 acts through a different enzyme. IL4 treatment increased invasion about 2 fold, and all the enzyme inhibitors then reduced it to the baseline level. These results demonstrate that IL4 treated microglia can use all three classes of ECM degrading enzymes for inva sion. Untreated microglia were more restricted, using primarily cysteine cathepsins. The microglial activation state alters expression of ECM degrading enzymes Based on the differences in migration and enzymes Inhibitors,Modulators,Libraries used for invasion in unstimulated versus IL4 treated microglia, we next compared transcript expression of several ECM degrading enzymes. LPS treated cells were also examined because they degraded Inhibitors,Modulators,Libraries fibronectin despite being poorly migratory.

For eight of the nine enzymes examined, the pattern was unique to the stimulus. LPS treated microglia had increased MMP9, MMP12, MMP14, heparanase and Cat L1. In IL4 treated micro glia only MMP2, Cat S and Cat K increased, which Inhibitors,Modulators,Libraries is consistent with the unique contribution of Cat S and Cat K to invasion in IL4 treated cells. Given the small increase in MMP2 only, and the increase in the general MMP inhibitor, TIMP metallopeptidase inhibitor 1, we were surprised that invasion by IL4 treated capacity in both 2 D and 3 D assays. We found that LPS treated micro glia were less migratory. Previous reports are inconsist ent, and while the reasons are not clear, the effect of LPS on migration might depend on Inhibitors,Modulators,Libraries species and strain, cell type and age. Impaired migration has been reported for neonatal rat and adult human microglia, and for guinea pig peritoneal macrophages and rabbit alveolar macrophages.

Conversely, some studies reported that LPS can increase migration in the RAW264. 7 macrophage cell line and primary rat peritoneal macrophages, but the LPS dose was not stated. Interestingly, migration of peritoneal macrophages was mildly inhibited by LPS in LPS sensitive mouse strains but increased in LPS resistant mice, al though only at LPS doses greater than different 50 ng ml.