• Asian-Australasian Journal of Animal Sciences
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• v.27 no.5
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• pp.733-742
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• 2014

The glucagon-like peptide 2 (GLP-2) that is expressed in intestine epithelial cells of mammals, is important for intestinal barrier function and regulation of tight junction (TJ) proteins. However, there is little known about the intracellular mechanisms of GLP-2 in the regulation of TJ proteins in piglets' intestinal epithelial cells. The purpose of this study is to test the hypothesis that GLP-2 regulates the expressions of TJ proteins in the mitogen-activated protein kinase (MAPK) signaling pathway in piglets' intestinal epithelial cells. The jejunal tissues were cultured in a Dulbecco's modified Eagle's medium/high glucose medium containing supplemental 0 to 100 nmol/L GLP-2. At 72 h after the treatment with the appropriate concentrations of GLP-2, the mRNA and protein expressions of zonula occludens-1 (ZO-1), occludin and claudin-1 were increased (p<0.05). U0126, an MAPK kinase inhibitor, prevented the mRNA and protein expressions of ZO-1, occludin, claudin-1 increase induced by GLP-2 (p<0.05). In conclusion, these results indicated that GLP-2 could improve the expression of TJ proteins in weaned pigs' jejunal epithelium, and the underlying mechanism may due to the MAPK signaling pathway.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.2
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• pp.236-245
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• 2017

Objective: The study was to investigate the effects of alanyl-glutamine (Ala-Gln) and glutamine (Gln) supplementation on the intestinal mucosa barrier in piglets. Methods: A total of 180 barrows with initial weight $10.01{\pm}0.03kg$ were randomly allocated to three treatments, and each treatment consisted of three pens and twenty pigs per pen. The piglets of three groups were fed with control diet [0.62% alanine (Ala)], Ala-Gln diet (0.5% Ala-Gln), Gln diet (0.34% Gln and 0.21% Ala), respectively. Results: The results showed that in comparison with control diet, dietary Ala-Gln supplementation increased the height of villi in duodenum and jejunum (p<0.05), Gln supplementation increased the villi height of jejunum (p<0.05), Ala-Gln supplementation up-regulated the mRNA expressions of epidermal growth factor receptor and insulin-like growth factor 1 receptor in jejunal mucosa (p<0.05), raised the mRNA expressions of Claudin-1, Occludin, zonula occludens protein-1 (ZO-1) and the protein levels of Occludin, ZO-1 in jejunal mucosa (p<0.05), Ala-Gln supplementation enlarged the number of goblet cells in duodenal and ileal epithelium (p<0.05), Gln increased the number of goblet cells in duodenal epithelium (p<0.05) and Ala-Gln supplementation improved the concentrations of secretory immunoglobulin A and immunoglobulin G in the jejunal mucosa (p<0.05). Conclusion: These results demonstrated that dietary Ala-Gln supplementation could maintain the integrity of small intestine and promote the functions of intestinal mucosa barriers in piglets.

• Korean Journal of Veterinary Pathology
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• v.3 no.1
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• pp.35-44
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• 1999

The morphologic changes of small intestinal epithelium in pigs diagnosed as porcine epidemic diarrhea(PED} by virus isolation and immunohistochemistry were studied through light microscope and transmissible electron microscope. On semi-thin section, the histologic findings showed severe villous atrophy and fusion with hyperplasia of cuboidal epithelium in the villi, inflammatory cell infiltration in lamina propria, and increased mitotic figures in the crypt. The structural changes were mostly restricted to the cytoplasm of affected absorptive epithelium of villi. 3 types of epithelial changes were found; degenerated virus-affected cells, undifferentiated cuboidal cells, and normal columnar cells. On electron microscopy, round to spherical viral particles of 50∼l00nm in diameter were found within the dilated vesicles and endoplasmic reticulums of degenerated cells, which had decreased their cytoplasmic electron density due to dilated and missing organelles(e.g. mitochondria, ERs, etc.). Microvilli were shortened and sparse, leaving denuded terminal web of the villous epithelial cells. Fat globules were often found within slightly degenerated enterocytes. On the tip of villi, severely damaged cells were exfoliated and replaced by undifferentiated cuboidal cells We found distinct ultrastructural changes in the jejunal epithelium confirming PED virus infection is involved in malabsorptive diarrhea.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.12
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• pp.1790-1797
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• 2002

Lactic acid bacteria were isolated from piglets and chicken and characterized. Lactic acid bacteria showing resistance to low pH and bile, adhesion to intestinal epithelium cells, and the inhibition of Escherichia coli and Salmonella spp. were identified as Lactobacillus acidophilus. L. acidophilus PF01 survived for 2 h in MRS broth adjusted to pH 2. L. acidophilus CF07 was less resistant than L. acidophilus PF01 to pH 2, but survived at pH 2.5 for 2 h. Both of isolates were able to grow in MRS broth containing 0.3% (w/v) bile, with L. acidophilus CF07 being more tolerant to bile than L. acidophilus PF01. L. acidophilus PF01 and CF07 adhered specifically to the duodenal and jejunal epithelium cells of piglet, and the cecal and duodenal epithelium cells of chicken, respectively. Both of isolates did not adhere to the epithelium cells of the various animal intestines from which they were isolated. When L. acidophilus was cultured with E. coli and Salmonella spp. in MRS broth, MRS broth containing 2% skim milk powder or modified tryptic soy broth at $37^{\circ}C$, L. acidophilus PF01 and CF07 inhibited the growths of E. coli K88 and K99, and S. enteritidis and S. typhimurium, respectively. Both of isolates were found to possess the essential characteristics of probiotic lactic acid bacteria for piglet and chicken.

• Microbiology and Biotechnology Letters
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• v.35 no.2
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• pp.98-103
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• 2007

To isolate probiotic lactic acid bacteria for animal, we have screened the microorganisms from chicken feces, by random selection and agar well diffusion assay. Among them, CPM-7 strain showing superior inhibitory activity against Escherichia coli was selected. By examining carbohydrates utilization, morphologic property and 16S rRNA gene sequence, CPM-7 strain was identified as Lactobacillus salivarius, then named L. salivarius CPM-7. L. salivarius CPM-7 produced thirteen enzymes in the test using API ZYM kit, and showed resistance to low pH and bile salts. It survived at pH 2 for 30 min. and pH 3 for 6 hr. And, it was able to grow in MRS medium containing 0.2% (w/v) bile salts. L. salivarius CPM-7 adhered to the jejunal epithelium cells of pig. Both the supernatant of L. salivarius CPM-7 and the its neutralized one showed high inhibitory activity against E. coli K88.

• Radiation Oncology Journal
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• v.12 no.3
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• pp.271-284
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• 1994

Purpose : Phospholipase C(PLC) isozymes play significant roles in transmembrane signal transduction. PLC-${\gamma}1$ acts as the intracellular effector in signal transduction for cellular proliferation and differentiation. Ras oncoprotein is also involved in cell growth. We determined the biological significance of PLC and ras oncoprotein in regeneration following radiation and the effect of different modes of administration of 5-FU. Materials and Methods : To determine the effect of the administration mode of 5-FU on the regeneration of intestinal mucosa of rats following radiation, we compared the expression of PLC and ras oncoprotein in six groups. Group I had no treatment. Group II received radiation(8 Gy) only. Group III received radiation(8 Gy) and 5-FU(150mg/kg) continuous intravenous (iv) infusion for 12 hours. Group IV received radiation(8 Gy) and 5-FU(750mg/kg) iv bolus injection. Group V received only 5-FU(150mg/kg) continuous iv infusion for 12 hours, Group VI received only 5-FU (150mg/kg) iv bolus injection. Through immunoblotting and immunohistochemistry, we examined the expression of PLC and ras oncoprotein in rat jejunum at 96 hours after radiation or 5-FU administration and at 120 hours after radiation and 5-FU adminstration. We also investigated the histological findings using hematoxylin and eosin stain. Results : In the immunohistochemistry study, PLC-${\gamma}1$ expression was the highest in group III followed by groups II and VI in that order and was weakly positive in groups V and VI. PLC-${\gamma}1$ was hardly detected in the control group. The expression of ras oncoprotein was the same as the PLC-${\gamma}1$ expression for all groups. These results were confirmed by the histological findings regarding the mucosal regeneration. In the immunoblotting analysis, PLC-${\gamma}1$ expression was the highest in group III followed by group IV and II in that order. This difference between the immunoblotting and immunohistochemistry study was due to the high expression of PLC-${\gamma}1$ on the damaged surface epithelium rather than to its expression in the regeneration region as observed in the immunohistochemistry study for group IV. The expression of PLC-${\delta}1$ was positive only in group V and VI, which received both radiation and 5-FU, and the expression of PLC-${\beta}1$ was negligible for all groups. Conclusion : These results suggest that PLC-${\gamma}1$ mediated signal transduetion and ras oncoprotein may have a significant role in mucosal regeneration after radiation, and that continuous iv infusion of 5-FU may induce active regeneration in intestinal mucosa following radiation. In addition, the expression of PLC-${\delta}1$ in combined group of radiation and 5-FU implies that PLC-${\delta}1$ may be involved in signal transduction mediated by concerted action between radiation and 5-FU.

• Radiation Oncology Journal
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• v.15 no.2
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• pp.79-95
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• 1997

Purpose : Phospholipase C(PLC) isozymes play significant roles in signal transduction mechanism. $PLC-\gamma$ 1 is one of the key regulatory enzymes in signal transduction for cellular proliferation and differentiation. Ras oncoprotein, EGFR, and PKC are also known to be involved in cell growth. The exact mechanisms of these signal transduction following irradiation, however, were not clearly documented Thus, this study was Planned to determine the biological significance of PLC, ras oncoprotein, EGFR, and PKC in damage and regeneration of rat intestinal mucosa following irradiation. Material and Method : Sixty Sprague-Dawley rats were irradiated to entire body with a single dose of 8Gy. The rats were divided into S groups according to the sacrifice days after irradiation. The expression of PLC, ras oncoprotein, EGFR and PKC in each group were examined by the immunoblotting and immunohistochemistry. The histopathologic findings were observed using H&I stain, and the mitoses for the evidence of regeneration were counted using the light microscopy & PCNA kit. The Phosphoinositide(PI) hydrolyzing activity assay was also done for the indirect evaluation of $PLC-\gamma$ 1 activity. Results: In the immunohistochemistry , the expression of $PLC-{\beta}$ was negative for all grøups. The expression of $PLC-{\gamma}1$ was highest in the group III followed by group II in the proliferative zone of mucosa. The expression of $PKC-{\delta}1$ was strongly positive in group 1 followed by group II in the damaged surface epithelium. The above findings were also confirttled in the immunoblotting study. In the immunoblotting study, the expressions of $PLC-{\beta}$, $PLC-{\gamma}1$, and $PKC-{\delta}1$ were the same as the results of immunohis-tochemistry. The expression of ras oncoprctein was weakly positive in groups II, III and IV. The of EGFR was the highest in the group II, III, follwed by group IV and the expression of PKC was weakly positive in the group II and III. Conclusion: $PLC-{\gamma}1$ mediated signal transduction including ras oncoprotein, EGFR, and PKC play a significant role in mucosal regeneration after irradiation. $PLC-{\delta}1$ mediated signal transduction might have an important role in mucosal damage after irradiation. Further studies will be necessary to confirm the signal transduction mediating the $PKC-{\delta}1$.