Presence of mRNA for VIP and Substance P and presence of VPAC1 and NK-1 receptor expressions in the colonic epithelium of man: changed pattern in ulcerative colitis
(English)Manuscript (Other academic)
The neuropeptides vasoactive intestinal peptide (VIP) and substance P (SP) are considered to be important in ulcerative colitis (UC). It is generally assumed that the main source of VIP and SP in the intestine is the innervation. There is no information concerning whether or not they are produced by cells in the epithelial layer. Concerning UC, there is also a lack of information concerning the VIP-receptor VPAC1 in the epithelium. In the present study, UC and non-UC colon was examined concerning expressions of VIP, SP, VPAC1 and the SP-preferred receptor, neurokinin-1 (NK-1R). Both immunohistochemistry and in situ hybridization were applied. mRNA expression for both VIP and SP were observed in the epithelium. The mRNA reactions were seen in normal and little/moderately affected mucosa. There were very marked VPAC1 immunoreactions in the epithelium, in non-UC mucosa and in little affected UC mucosa. A decrease in VPAC1 immunoreactions was noted in the epithelium in markedly affected UC mucosa. Existence of VIP immunoreaction, VIP mRNA, VPAC1 immunoreaction, SP mRNA, NK-1R immunoreaction and Substance P receptor (TACR1) mRNA was shown for cells in lamina propria and submucosa. The present study shows unexpectedly that mRNA for both VIP and SP are not only expressed in neuronal perikarya and lamina propria and submucosal cells but also in the colonic epithelium, and that marked changes in VPAC1 receptor expressions occur for this layer in severe UC. It is tentative to speculate that autocrine/paracrine VIP and SP effects may occur within the epithelium. The decrease in VPAC1 receptor reactions seen in severely UC affected mucosa may be a drawback for the intestinal function.
colitis, colonic epithelium, SP, VIP, VPAC1, NK-1 receptor
Cell and Molecular Biology
Research subject Human Anatomy
IdentifiersURN: urn:nbn:se:umu:diva-19945OAI: oai:DiVA.org:umu-19945DiVA: diva2:207792