Changes in the expression of galanin and galanin receptors in the wall of the colon in pigs experimentally infected with Brachyspira hyodysenteriae

Abstract

The expression of galanin (GAL) and its three receptors (GalR1, GalR2, and GalR3) were studied with real-time PCR in the colonic wall of pigs suffering from experimental colitis caused by the infection with Brachyspira hyodysenteriae. The expression was studied in the muscular membrane, mucosa/submucosa layer, and in lymphocytes isolated from mucosa/submucosa. The expression levels were normalized to glyceraldehyde-6-phosphate dehydrogenase (GAPDH) expression and compared to expression levels in control animals. GAL expression was found in all three studied compartments of the colonic wall. A significant decrease in GAL expression level was found in the mucosa/submucosa and in isolated lymphocytes, whereas the decrease was much less profound in the muscular membrane. In the case of galanin receptors their expression was found in all studied compartments of the colonic wall, however at different levels, as compared to GAPDH expression. The decrease of galanin receptors expression was found in all studied compartments of the colonic wall of the sick animals.

Galaninergic intramural nerve and tissue reaction to antral ulcerations

“…48 This study has revealed that only in the stomach tissues directly adjacent to the ulcer, thus affected by acute inflammatory process, the expression of both subtypes of galanin receptors was increased. However, previous studies have demonstrated that in the porcine pylorus 25 and in the colon 36 their expressions were not significantly changed and even distinctly decreased, respectively. Although, as mentioned before, in the latter study the tissue degradation might have affected the results, all these variations between different parts of the por- Although the functional significance of data gained from the present experiment have to be further verified by other scientific disciplines, based on the literature review it is tempting to speculate that galanin is strongly involved in protective and recovery processes, transduction of pain and, partially, in the modulation of the peristalsis in the (porcine) stomach.…”

“…This study has revealed that only in the stomach tissues directly adjacent to the ulcer, thus affected by acute inflammatory process, the expression of both subtypes of galanin receptors was increased. However, previous studies have demonstrated that in the porcine pylorus and in the colon their expressions were not significantly changed and even distinctly decreased, respectively. Although, as mentioned before, in the latter study the tissue degradation might have affected the results, all these variations between different parts of the porcine gastrointestinal tract indicate a unique role played by each receptor in response of individual tissues to the pathology.…”

“…In dysenteric pigs, tissue concentration of galanin determined with ELISA was significantly increased in the colon while in the ileum it was comparable to that found in the intact animals . Interestingly, investigations with application of Q‐PCR have revealed a prominent decrease in tissue levels of mRNA encoding galanin and all its receptor subtypes (GalR1, GalR2, GalR3) in the porcine colon affected with dysenteric inflammation as well as in lymphocytes isolated from this part of the intestine . The decrease in galanin expression observed in the colon samples could partially result from the fact that intestinal tissues were heavily damaged by the severe pathological process and some structures expressing galanin and its receptors were destroyed.…”

“…The present results are in agreement with earlier studies in humans and mice, which revealed elevated GalR1 expression in tissues of the colon affected by naturally developing or experimentally induced inflammation. [42][43][44][45][46][47] The information on the expression of GalR2 and GalR3 in the course of inflammation is very limited and deals with such tissues as the porcine pylorus (our previous study 25 ), porcine colon and lymphocytes, 36 and mouse calvaria. 48 This study has revealed that only in the stomach tissues directly adjacent to the ulcer, thus affected by acute inflammatory process, the expression of both subtypes of galanin receptors was increased.…”

The Influence of Gastric Antral Ulcerations on the Expression of Galanin and GalR1, GalR2, GalR3 Receptors in the Pylorus with Regard to Gastric Intrinsic Innervation of the Pyloric Sphincter

“…Then, from each cDNA sample Real-Time PCRs were performed for the following genes: Gal, GalR1, GalR2, GalR3 and porcine glyceraldehyde 3-phosphate dehydrogenase (GAPDH) as the housekeeping gene, each in triplicate. The primers were designed with Primer-BLAST software ( http://ncbi.nlm.nih.gov ) and their detailed descriptions are enclosed in our previous study [ 37 ]. Sequences of primers are shown in Table 1 .…”