T1831 5-HT3 Receptor in the Submucousal Plexus Mediates Inhibition of Serotonin-Induced Secretion in Rat Distal Colon

Genisphere FlashTag Kit and hybridized to Invitrogen NCode Multi-Species miRNA Microarray V2 in a Maui hybridization station.Processed slides were scanned in an Agilent DNA microarray scanner.Resulting images was analyzed and ratio of median normalized using GenePix Pro 6.0.Four biological replicates were used for each comparison.Samples were hybridized to four arrays in a dual color dye swap microarray experimental design.BRB ArrayTools were used for fold change and statistical calculations.Selected miRNA data from the array analysis were validated using TaqMan real-time PCR miRNA assays.Results: The array probes for 250 mouse miRNAs and out these significant expression of 48 miRNAs was detected in the fundus and 57 in the antrum.When comparing the expression of miRNA in fundus and antrum, 2 of the miRNA expressed in both tissues had a higher expression in the fundus whereas 5 had a higher expression in the antrum.Loss of gastrin and subsequent achlorhydria and inflammation caused an up regulation of 6 miRNAs and down regulation of 5 in the antrum.In the fundus, one miRNA was up regulated and one down regulated.Infection with H. pylori caused the up regulation of 4 miRNA in the antrum and the down regulation of 2. In contrast H. pylori infection only one miRNA was unregulated in the fundus of the infected mice (miR-449b).Among the miRNAs up regulated the gastric antrum in both the gastrin KO as well as the H. pylori infected mice was Let-7.Up regulation of Let-7 has been associated with increased STAT3 activation.STAT3 activation has recently is one of the key steps in gastric carcinogenesis.Others and we have shown that over time gastrin KO mice.Conclusion: We found expression of 20-25% of the miRNA for which we examined which comparable to the expression of miRNA in other tissues.Some of the changes we identified, also suggest that miRNAs are indeed involved in the gastritis-atrophyintestinal metaplasia-carcinoma sequence.