PMID- 9727370 OWN - NLM STAT- MEDLINE DCOM- 19981209 LR - 20210518 IS - 1046-6673 (Print) IS - 1046-6673 (Linking) VI - 9 IP - 9 DP - 1998 Sep TI - Regulation of nuclear factor kappaB by corticosteroids in rat mesangial cells. PG - 1620-8 AB - Nuclear factor kappaB (NF-kappaB) is one of the most important proinflammatory transcription factors. The anti-inflammatory activity of steroids in leukocytes is partly due to inhibition of signaling by NF-kappaB, but it is not known whether steroids inhibit NF-kappaB in kidney cells. Since the mesangial cell is important in several kidney diseases, especially mesangial proliferative glomerulonephritis, the aims of this study were: (1) to define the mechanism of NF-kappaB activation in rat glomerular mesangial cells; and (2) to determine whether steroids inhibit activation of NF-kappaB in these cells. Electrophoretic mobility shift assays (EMSA) showed that interleukin-1beta and tumor necrosis factor-alpha activated NF-kappaB from 15 min to 48 h after stimulation. Supershift EMSA demonstrated that p65 and p50 were the predominant subunits involved. Degradation of the inhibitory subunit IkappaB-alpha was first observed 15 min after stimulation by Western blot, was maximal at 15 to 30 min (>90% by densitometry), and had returned to near normal levels at 90 min. In contrast, IkappaB-beta was maximally degraded at 60 to 120 min and was still reduced at 48 h (<50% of the untreated level). Although treatment of mesangial cells with dexamethasone increased IkappaB-alpha mRNA by 1.92x and protein by 1.45x over controls, pretreatment did not inhibit degradation of IkappaB-alpha or -beta in response to stimulation, or prevent the increase in NF-kappaB binding activity shown by EMSA. However, dexamethasone significantly inhibited the increase in monocyte chemoattractant protein-1 mRNA seen after stimulation with interleukin 1beta, although this was not complete. It did not reduce transcription of an NF-kappaB reporter. In comparison, the pyrrolidine derivative of dithiocarnamate (PDTC), a known inhibitor of NF-kappaB, prevented the increase in NF-kappaB binding activity and significantly reduced transcription of the NF-kappaB reporter. These studies suggest that steroids can partially inhibit transcriptional activation by NF-kappaB in mesangial cells but not through an increase in IkappaB-alpha protein alone. Their effect must occur at the promoter and may be restricted to some NF-kappaB-responsive genes. Therapies that block NF-kappaB more effectively than steroids in mesangial cells, therefore, may be useful in the treatment of mesangial proliferative glomerulonephritis. FAU - Auwardt, R B AU - Auwardt RB AD - Immunology Research Centre, St. Vincent's Hospital, Melbourne, Victoria, Australia. FAU - Mudge, S J AU - Mudge SJ FAU - Chen, C G AU - Chen CG FAU - Power, D A AU - Power DA LA - eng PT - Comparative Study PT - Journal Article PT - Research Support, Non-U.S. Gov't PL - United States TA - J Am Soc Nephrol JT - Journal of the American Society of Nephrology : JASN JID - 9013836 RN - 0 (Adrenal Cortex Hormones) RN - 0 (DNA, Complementary) RN - 0 (Glucocorticoids) RN - 0 (Interleukin-1) RN - 0 (NF-kappa B) RN - 0 (RNA, Messenger) RN - 0 (Tumor Necrosis Factor-alpha) RN - 7S5I7G3JQL (Dexamethasone) SB - IM MH - Adrenal Cortex Hormones/*metabolism/pharmacology MH - Animals MH - Base Sequence MH - Blotting, Northern MH - Blotting, Western MH - Cells, Cultured MH - DNA, Complementary/analysis MH - Dexamethasone/pharmacology MH - Glomerular Mesangium/cytology/drug effects/*metabolism MH - Glucocorticoids/pharmacology MH - Interleukin-1/metabolism/pharmacology MH - Molecular Sequence Data MH - NF-kappa B/drug effects/*metabolism MH - Polymerase Chain Reaction MH - RNA, Messenger/analysis MH - Rats MH - Rats, Sprague-Dawley MH - Reference Values MH - Sensitivity and Specificity MH - Tumor Necrosis Factor-alpha/metabolism/pharmacology EDAT- 1998/09/04 00:00 MHDA- 1998/09/04 00:01 CRDT- 1998/09/04 00:00 PHST- 1998/09/04 00:00 [pubmed] PHST- 1998/09/04 00:01 [medline] PHST- 1998/09/04 00:00 [entrez] AID - 10.1681/ASN.V991620 [doi] PST - ppublish SO - J Am Soc Nephrol. 1998 Sep;9(9):1620-8. doi: 10.1681/ASN.V991620.