Suppression of cytokine responses by indomethacin in podocytes: a mechanism through induction of unfolded protein response.
We found that, in murine podocytes, expression of monocyte chemoattractant protein 1 (MCP-1) in response to TNF-alpha was suppressed by indomethacin but not by ibuprofen. This anti-inflammatory potential was correlated with induction of 78-kDa glucose-regulated protein (GRP78), a marker of unfolded protein response (UPR). Indomethacin, but not ibuprofen, also triggered expression of CHOP, another endogenous indicator of UPR, as well as repression of endoplasmic reticulum stress-responsive alkaline phosphatase, an exogenous indicator of UPR. Like ibuprofen, other nonsteroidal anti-inflammatory drugs including aspirin and sulindac also did not induce UPR, indicating that the induction of UPR by indomethacin was independent of cyclooxygenase inhibition. The induction of UPR by indomethacin was observed similarly in other cells including mesangial cells and tubular epithelial cells. In tumor necrosis factor (TNF)-alpha-treated cells, suppression of MCP-1 by indomethacin was inversely correlated with induction of UPR, and other inducers of UPR including tunicamycin, thapsigargin, and A23187 reproduced the suppressive effect. Reporter assays showed that indomethacin as well as thapsigargin attenuated activation of NF-kappaB by TNF-alpha, and it was associated with enhanced degradation of TNF receptor-associated factor 2 (TRAF2) and blunted degradation of IkappaBbeta. Subsequent experiments revealed that acute ablation of GRP78 protein by AB5 subtilase cytotoxin caused reinforcement of MCP-1 induction and NF-kappaB activation by TNF-alpha and that transfection with GRP78 significantly suppressed the cytokine-induced activation of NF-kappaB. These results suggested that indomethacin suppressed the response of podocytes to TNF-alpha via UPR and that UPR-triggered induction of GRP78 and degradation of TRAF2 may be responsible, at least in part, for the suppressive effect of indomethacin.
Okamura
Maro
M
Department of Molecular Signaling, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Shimokato 1110, Chuo, Yamanashi 409-3898, Japan.
Takano
Yosuke
Y
Hiramatsu
Nobuhiko
N
Hayakawa
Kunihiro
K
Yao
Jian
J
Paton
Adrienne W
AW
Paton
James C
JC
Kitamura
Masanori
M
D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D015152:Blotting, Northern; D015153:Blotting, Western; D002460:Cell Line; D002478:Cells, Cultured; D018932:Chemokine CCL2 / Q000235:genetics / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000187:drug effects* / Q000378:metabolism; D000091342:Endoplasmic Reticulum Chaperone BiP; D029968:Escherichia coli Proteins / Q000494:pharmacology; D015870:Gene Expression / Q000187:drug effects; D018840:HSP70 Heat-Shock Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D007052:Ibuprofen / Q000494:pharmacology; D007213:Indomethacin / Q000494:pharmacology*; D051379:Mice; D008954:Models, Biological; D018832:Molecular Chaperones / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism; D047495:PPAR gamma / Q000378:metabolism; D050199:Podocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D017510:Protein Folding / Q000187:drug effects; D011506:Proteins / Q000235:genetics / Q000378:metabolism; D013381:Subtilisins / Q000494:pharmacology; D047992:TNF Receptor-Associated Factor 2 / Q000378:metabolism; D019284:Thapsigargin / Q000494:pharmacology; D051742:Transcription Factor CHOP / Q000235:genetics / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D000894:Anti-Inflammatory Agents, Non-Steroidal; C491768:Ccl2 protein, mouse; D018932:Chemokine CCL2; C497250:Ddit3 protein, mouse; D000091342:Endoplasmic Reticulum Chaperone BiP; D029968:Escherichia coli Proteins; D018840:HSP70 Heat-Shock Proteins; D006360:Heat-Shock Proteins; C000717248:Hspa5 protein, mouse; D018832:Molecular Chaperones; D016328:NF-kappa B; D047495:PPAR gamma; D011506:Proteins; D047992:TNF Receptor-Associated Factor 2; D014409:Tumor Necrosis Factor-alpha; C050087:oxygen-regulated proteins; D051742:Transcription Factor CHOP; D019284:Thapsigargin; D013381:Subtilisins; C527234:subtilase cytotoxin, E coli; D007052:Ibuprofen; D007213:Indomethacin