SB203580

Br J Pharmacol,2000 Sep;131(1):99-107.

The p38 MAP kinase inhibitor SB203580 enhances nuclear factor-kappa B transcriptional activity by a non-specific effect upon the ERK pathway.[Pubmed: 10960075]

METHODS AND RESULTS:
In the present study we investigated a possible role for the p38 mitogen-activated protein (MAP) kinase pathway in mediating nuclear factor-kappa B (NF-kappaB) transcriptional activity in the erythroleukaemic cell line TF-1. TF-1 cells stimulated with the phosphatase inhibitor okadaic acid (OA) demonstrated enhanced NF-kappaB and GAL4p65-regulated transcriptional activity which was associated with elevated p38 phosphorylation. However, pretreatment with the p38 MAPK specific inhibitor SB203580 (1 microM) or overexpression of kinase-deficient mutants of MKK3 or MKK6 did not affect OA-enhanced NF-kappaB transcriptional potency, as determined in transient transfection assays. In fact, 5 and 10 microM SB203580 enhanced rather than inhibited NF-kappaB-mediated promoter activity by 2 fold, which was independent of phosphorylation of the p65 subunit. The SB203580-mediated increase in NF-kappaB transcriptional activity was associated with enhanced phosphorylation of extracellular signal-regulated kinase (ERK)1/2 and c-Jun N-terminal kinase (JNK), but not p38 kinase. Overexpression of kinase-deficient mutants belonging to the ERK1/2, JNK, and p38 pathways showed that only dominant-negative Raf-1 abrogated SB203580-enhanced NF-kappaB activity. This would implicate the involvement of the ERK1/2 pathway in the enhancing effects of SB203580 on NF-kappaB-mediated gene transcription.
CONCLUSIONS:
This study demonstrates that the p38 MAP kinase pathway is not involved in the OA-induced activation of NF-kappaB. SB203580 at higher concentrations activates the ERK pathway, which subsequently enhances NF-kappaB transcriptional activity.

J Biol Chem,2000 Mar 10;275(10):7395-402.

The pyridinyl imidazole inhibitor SB203580 blocks phosphoinositide-dependent protein kinase activity, protein kinase B phosphorylation, and retinoblastoma hyperphosphorylation in interleukin-2-stimulated T cells independently of p38 mitogen-activated protein kinase.[Pubmed: 10702313]

Cell lines: CT6 cell , BA/F3 F7 cell
Concentrations:  0–30 μM
Incubation Time:  1 hour
Method:
CT6 cell and BA/F3 F7 cell are rested by washing three times in RPMI and culturing overnight in RPMI, 5% fetal calf serum in the absence of growth factor, antibiotics, or β-mercaptoethanol supplements. 2–5 × 106 rested CT6 cells are resuspended in 2 mL of RPMI, 5% fetal calf serum and preincubated with SB203580 or vehicle control as indicated in figure legends. Cells are then stimulated with 20 ng/ml recombinant human IL-2 for 5 minutes at 37  °C and pelleted in a minifuge for 30 seconds, medium is aspirated, and the pellet is lysed in the appropriate buffer. BA/F3 cells stably expressing deletion mutants of IL-2 receptor β chain are maintained in glutamine containing RPMI further supplemented with 5% fetal calf serum and 0.2 μg/mL G418. The cells are then washed extensively, rested overnight, and washed again before activating with IL-2; such cell preparations are >90% T cells. Cellular proliferation assays are performed by measurement of [3H]thymidine incorporation.

Int Immunopharmacol,2011 Sep;11(9):1319-26.

The selective p38 mitogen-activated protein kinase inhibitor, SB203580, improves renal disease in MRL/lpr mouse model of systemic lupus.[Pubmed: 21549858]

Animal Models: Systemic lupus erythematosus (SLE) are established in female MRL/lpr mice and female C57BL/6 mice
Dosages:0.1 M/day
Administration: Orally administered