Figure 5.

Western blot analysis demonstrated the inhibitory effects of minocycline, sulforaphane and SB203580 on the protein expression of the p65 subunit of nuclear factor-κB and mitogen-activated protein kinases in cultured retinal microglial cells. A: The protein expression of the p65 subunit of NF-κB and p-p38, p-p44/42, and p-JNK MAPKs in cultured microglia with or without LPS administration. The cultured retinal microglial cells constitutively expressed high levels of p-p44/42, but expressed low levels of p-p38, p-JNK, and the p65 subunit of NF-κB without LPS administration. Following exposure to LPS, the expression of p-p38, p-JNK, and the p65 subunit of NF-κB was upregulated. However, the expression of p-p44/42 was not changed. The ERK2 MAPK was used to assay total (phospho-independent) ERK and served as a control to ensure that equivalent quantities of proteins were used for SDS-PAGE. B: Pretreatment with minocycline, sulforaphane or SB203580 completely inhibited LPS-induced upregulation of p-p38, but had no effect on the expression of p-p44/42, p-JNK, and the p65 subunit of NF-κB.