Substance P stimulates cyclooxygenase-2 and prostaglandin E2 expression through JAK-STAT activation in human colonic epithelial cells.
Substance P (SP) via its neurokinin-1 receptor (NK-1R) regulates several gastrointestinal functions. We previously reported that NK-1R-mediated chloride secretion in the colon involves formation of PG. PGE2 biosynthesis is controlled by cyclooxygenase-1 (COX-1) and COX-2, whose induction involves the STATs. In this study, we examined whether SP stimulates PGE2 production and COX-2 expression in human nontransformed NCM460 colonocytes stably transfected with the human NK-1R (NCM460-NK-1R cells) and identified the pathways involved in this response. SP exposure time and dose dependently induced an early (1-min) phosphorylation of JAK2, STAT3, and STAT5, followed by COX-2 expression and PGE2 production by 2 h. Pharmacologic experiments showed that PGE2 production is dependent on newly synthesized COX-2, but COX-1 protein. Inhibition of protein kinase Ctheta (PKCtheta), but not PKCepsilon and PKCdelta, significantly reduced SP-induced COX-2 up-regulation, and JAK2, STAT3, and STAT5 phosphorylation. Pharmacological blockade of JAK inhibited SP-induced JAK2, STAT3, and STAT5 phosphorylation; COX-2 expression; and PGE2 production. Transient transfection with JAK2 short-interferring RNA reduced COX-2 promoter activity and JAK2 phosphorylation, while RNA interference of STAT isoforms showed that STAT5 predominantly mediates SP-induced COX-2 promoter activity. Site-directed mutation of STAT binding sites on the COX-2 promoter completely abolished COX-2 promoter activity. Lastly, COX-2 expression was elevated in colon of mice during experimental colitis, and this effect was normalized by administration of the NK-1R antagonist CJ-12,255. Our results demonstrate that SP stimulates COX-2 expression and PGE2 production in human colonocytes via activation of the JAK2-STAT3/5 pathway.
Koon
Hon-Wai
HW
Gastrointestinal Neuropeptide Center, Division of Gastroenterology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
Zhao
Dezheng
D
Zhan
Yanai
Y
Rhee
Sang Hoon
SH
Moyer
Mary P
MP
Pothoulakis
Charalabos
C
D000818:Animals; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D002460:Cell Line; D003106:Colon / Q000187:drug effects* / Q000378:metabolism*; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism*; D004247:DNA / Q000235:genetics / Q000378:metabolism; D015232:Dinoprostone / Q000096:biosynthesis*; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D053614:Janus Kinase 2; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D016297:Mutagenesis, Site-Directed; D064729:Neurokinin-1 Receptor Antagonists; D011401:Promoter Regions, Genetic; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D018040:Receptors, Neurokinin-1 / Q000378:metabolism; D050791:STAT Transcription Factors / Q000378:metabolism*; D050796:STAT3 Transcription Factor / Q000378:metabolism; D050799:STAT5 Transcription Factor / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013373:Substance P / Q000494:pharmacology*
D064729:Neurokinin-1 Receptor Antagonists; D011518:Proto-Oncogene Proteins; D018040:Receptors, Neurokinin-1; D050791:STAT Transcription Factors; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; D050799:STAT5 Transcription Factor; D013373:Substance P; D004247:DNA; D051546:Cyclooxygenase 2; D011505:Protein-Tyrosine Kinases; C507924:JAK2 protein, human; C507926:Jak2 protein, mouse; D053614:Janus Kinase 2; D015232:Dinoprostone