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Peptide YY induces intestinal proliferation in peptide YY knockout mice with total enteral nutrition after massive small bowel resection. J Pediatr Gastroenterol Nutr 2009; 48:517-25. [PMID: 19367178 DOI: 10.1097/mpg.0b013e31818c5fd8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
OBJECTIVE In previous research, peptide YY (PYY) administered in supraphysiological doses did not induce significant proliferative effects in rats that were allowed to feed ad libitum after massive small bowel resection (SBR). The main reason may well have been the interference of endogenous PYY released from L cells in the distal bowel in response to the presence of augmented unabsorbed intraluminal nutrients. The purpose of the present study was to explore the effect of PYY on intestinal proliferation with total enteral nutrition (TEN) in a SBR model of PYY knockout (Pyy(-/-)) mice, which do not produce endogenous PYY. MATERIALS AND METHODS Pyy(-/-) mice were assigned into 3 experimental groups: sham mice (sham group) underwent bowel transection and reanastomosis, and received TEN; SBR mice (SBR group) underwent a 50% small bowel resection, and received TEN; and SBR-PYY mice (SBR-PYY group) underwent a 50% small bowel resection, received TEN, and were treated with PYY1-36 subcutaneously from day 2 postoperatively. Parameters of enterocyte proliferation and apoptosis were determined on day 8 following operation. RESULTS SBR-PYY mice demonstrated a significant increase in (vs SBR) bowel and mucosal weights, mucosal DNA and protein, villus height, and crypt depth in jejunum and ileum. SBR-PYY mice also showed an increased crypt cell proliferation index in jejunum and ileum and decreased villus cell apoptotic index in ileum compared with SBR animals. CONCLUSIONS In an SBR model of Pyy(-/-) mice, PYY induces proliferation of residual intestine with TEN.
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Zhang W, Li N, Zhu W, Shi Y, Zhang J, Li Q, Li J. Peptide YY induces enterocyte proliferation in a rat model with total enteral nutrition after distal bowel resection. Pediatr Surg Int 2008; 24:913-9. [PMID: 18512063 DOI: 10.1007/s00383-008-2176-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/08/2008] [Indexed: 01/01/2023]
Abstract
The main reason why enterocyte proliferative effects of peptide YY (PYY) have not been detected in rats undergoing massive small intestinal resection after feeding may have been the background activity of markedly increased endogenous PYY released from L cells in the distal gut in response to the intraluminal nutrients. The purpose of the present study was to evaluate the effects of PYY on enterocyte proliferation in a rat model of distal bowel resection (DBR) with total enteral nutrition (TEN). Male, adult Sprague-Dawley rats were assigned into three experimental groups: sham rats underwent bowel transection and reanastomosis, DBR rats underwent the resection of 40 cm distal small intestine and colon, and DBR-PYY rats underwent distal bowel resection as above, and were treated with PYY(1-36) from day 2 to day 14 postoperatively. During days 2-14 postoperatively, all animals received isocaloric TEN. At the endpoints, plasma PYY levels and parameters of enterocyte proliferation were determined. Compared with the sham group, DBR rats demonstrated a significant decrease in plasma PYY levels, and a significant increase in intestinal bowel and mucosal weight, mucosal DNA and protein content, villus height and crypt depth, and crypt cell proliferation index. Administration of PYY (DBR-PYY group) led to a significant increase in plasma PYY levels, intestinal bowel and mucosal weight, mucosal DNA and protein content, villus height and crypt depth, and crypt cell proliferation index in comparison with the DBR untreated group. We conclude that administration of PYY increases the plasma PYY levels, and PYY induces enterocyte proliferation with TEN after distal bowel resection.
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Affiliation(s)
- Wei Zhang
- Research Institute of General Surgery, Jinling Hospital, Medical School of Nanjing University, Nanjing, China
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Rizvi IA, Robinson K, McFadden DW, Riggs DR, Jackson BJ, Vona-Davis L. Peptide YY Reverses TNF-α Induced Transcription Factor Binding of Interferon Regulatory Factor-1 and p53 in Pancreatic Acinar Cells. J Surg Res 2006; 136:25-30. [PMID: 16978650 DOI: 10.1016/j.jss.2006.05.028] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2006] [Revised: 05/12/2006] [Accepted: 05/16/2006] [Indexed: 01/28/2023]
Abstract
BACKGROUND Cytokine activation in the pancreatitis induces local and systemic cellular damage. Transcription factors interferon regulatory factor-1 (IRF-1) and the tumor suppressor gene p53 collaborate to enhance p21 related cell cycle regulation during pathological disease progression. However, little is known about their role in the pancreas after cytokine challenge. Our laboratory has previously shown that TNF-alpha induces the binding of many transcription factors, including NF-kappa B, and treatment with the gut hormone, Peptide YY (PYY), ameliorates the effects. We hypothesized that TNF-alpha would induce IRF-1 and p53 protein binding in pancreatic acinar cells and that PYY would attenuate the effect. MATERIALS AND METHODS Rat pancreatic acinar AR42J cells were treated with rat recombinant TNF-alpha (200 ng/ml). To verify that our model was inducing pancreatitis, alpha-amylase activity was measured in the cell culture supernatant by fluorescence spectroscopy. PYY [3-36] was added at 500 pM 30 min post-TNF treatment; cells were harvested at 2 h for extraction of nuclear protein. Transcription factor binding of IRF-1 and p53 were determined by protein/DNA array analysis using chemiluminescence detection, and relative spot densities were measured by densitometry. A two-fold increase or decrease in density was considered significant. RESULTS Amylase enzyme activity was significantly (P < 0.05) elevated in the TNF-alpha-treated cells by 2 h. Protein/DNA array analysis revealed significant up-regulation of both IRF-1 and p53 protein in nuclear extracts. Induction by TNF-alpha increased IRF-1 protein binding 3.5-fold, while binding levels of p53 protein increased six-fold. The addition of PYY to TNF-treated cells reduced IRF-1 and p53 binding to control levels. CONCLUSIONS We have shown for the first time that short-term exposure to TNF-alpha induces the binding activity of transcription factors IRF-1 and p53 in rat pancreatic acinar cells, and that addition of PYY reduces it. Regulation of transcription factor activity by PYY may have therapeutic potential in altering the progression of pancreatitis.
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Affiliation(s)
- Irfan A Rizvi
- Department of Surgery, West Virginia University, Morgantown, West Virginia 26506-9238, USA
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Oh NG, Son GM, Sin JY, Ding XZ, Adrian TE. Time-course of morphologic changes and peptide YY adaptation in ileal mucosa after loop ileostomy in humans. Dis Colon Rectum 2005; 48:1287-94. [PMID: 15789123 DOI: 10.1007/s10350-004-0915-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
PURPOSE The secretion mechanism of peptide YY involves systemic factors, such as humoral and neural stimuli, and local factors, such as intestinal peristalsis and intraluminal nutrients. This study was designed to survey the impact of local stimuli on the secretion of peptide YY under circumstances in which systemic stimuli are identical. METHODS Ileostomies were repaired within three months in a short-term group (14 patients) and after six months in a long-term group (14 patients). Mucosal peptide YY concentrations and cytomorphologic change, such as villus height, crypt depth, mucosal thickness, and villus index, were compared between proximal functioning ileum and a distal nonfunctioning ileal loop during ileostomy repair. In a control group of patients undergoing right hemicolectomy (21 cases), the normal distribution of peptide YY was measured in the mucosa throughout the distal ileum. RESULTS The peak of peptide YY concentration in the terminal ileum was 307.4 +/- 21 pmol/g, 25 cm from the ileocecal valve, with lower levels both proximally and distally. The mucosa of the functioning ileum in the short-term group showed hypertrophy, but had returned to preoperative levels in the long-term group. The nonfunctioning mucosa in both groups underwent atrophic changes. The mucosal peptide YY content in functioning ileum in the short-term group was higher than that of distal nonfunctioning mucosa (363.9 +/- 25.5 pmol/g vs. 284.1 +/- 13 pmol/g, P < 0.05), suggesting adaptive upregulation. The increments of mucosal peptide YY content in this short-term group compared with the control group were 45.6 and 4.7 percent in the proximal and distal segments, respectively. In the long-term group, proximal and distal mucosal peptide YY were similar (256.6 +/- 31.9 pmol/g vs. 254.9 +/- 27.1 pmol/g, P > 0.05), and there was no increment in either (1.3 vs. 4.4 percent, P > 0.05). CONCLUSIONS The peak concentrations of PYY in the ileal mucosa are found 20 to 25 cm proximal to the ileocecal valve. In the short-term response of ileostomy, local stimulatory factors play a major role in the adaptation of mucosal PYY. In the defunctioned bowel without luminal stimulation, systemic stimulation was important for maintenance of mucosal PYY.
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Affiliation(s)
- Nahm-Gun Oh
- Department of Surgery, Pusan National University School of Medicine, Pusan, Korea
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Yamazaki K, Yasuda N, Inoue T, Nagakura T, Kira K, Saeki T, Tanaka I. The combination of metformin and a dipeptidyl peptidase IV inhibitor prevents 5-fluorouracil-induced reduction of small intestine weight. Eur J Pharmacol 2004; 488:213-8. [PMID: 15044053 DOI: 10.1016/j.ejphar.2004.02.019] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2003] [Revised: 02/05/2004] [Accepted: 02/10/2004] [Indexed: 12/11/2022]
Abstract
Glucagon-like peptide 2 (GLP-2), which has intestinotrophic effects, is secreted from L-cells in the intestine in response to nutrient ingestion and is degraded by dipeptidyl peptidase IV (DPPIV). In this report, we show that biguanides promote GLP-2 release. Plasma GLP-2 levels were significantly increased by 1.4- to 1.6-fold in fasted F344 rats 1 h after oral meformin (300 mg/kg), phenformin (30 and 100 mg/kg) and buformin (100 mg/kg) treatment. In addition, metformin administration (300 mg/kg, p.o.) significantly elevated plasma GLP-2 in fasted CD-1 mice by about 2.0-fold 1 and 3 h after the treatment. Metformin and/or valine-pyrrolidide, a DPPIV inhibitor, was orally given (300 and 30 mg/kg, respectively, p.o., b.i.d., 3 days) to BALB/c mice treated with 5-fluorouracil (5-FU; 60 mg/kg, s.i.d.), which induces gastrointestinal damage leading to a reduction of small intestine wet weight. Metformin and valine-pyrrolidide co-administration prevented the 5-FU-induced reduction of wet weight of the small intestine, whereas metformin or valine-pyrrolidide alone had no effect. These results suggest that GLP-2 is co-secreted with GLP-1 flollowing biguanide stimulation, and that the combination of metformin with a DPPIV inhibitor might a useful oral treatment for gastrointestinal damage, based on GLP-2 actions.
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Affiliation(s)
- Kazuto Yamazaki
- Tsukuba Research Laboratories, Eisai Co., Ltd., 5-1-3 Tokodai, Tsukuba, Ibaraki 300-2635, Japan.
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Kazanjian KK, Towfigh S, McFadden DW. Peptide YY exhibits a mitogenic effect on pancreatic cells while improving acute pancreatitis in vitro. J Surg Res 2003; 114:95-9. [PMID: 13678704 DOI: 10.1016/s0022-4804(03)00218-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Peptide YY (PYY), a gastrointestinal regulatory peptide, improves survival and histologic parameters in animal models of acute pancreatitis. Its effects on pancreatic cell growth and acute pancreatitis in pancreatic acinar and ductal cells are unknown. We hypothesized that PYY would affect cell growth and attenuate acute pancreatitis in pancreatic acinar and ductal cells in vitro. METHODS Rat pancreatic acinar and ductal cells were cultured in the presence of 1) cerulein, a synthetic cholecystokinin analog that induces pancreatitis, 2) PYY, or 3) a combination group pretreated with PYY prior to addition of cerulein. Cell survival was measured at 48 h using MTT assay. Amylase secretion, as marker for pancreatitis, was measured at 48 h using an amylase activity assay. Statistical significance was calculated using analysis of variance and the Student's t test. RESULTS Peptide yy significantly increased cell growth and decreased amylase secretion compared with control and cerulein groups. Pretreatment with PYY significantly protected against the pancreatitis effects of cerulein. CONCLUSIONS We have shown for the first time that PYY has a mitogenic effect on pancreatic acinar and ductal cells in vitro. In addition, it directly protects against cerulein-induced pancreatitis. Its potential therapeutic benefit in acute pancreatitis would therefore be twofold: amelioration of the inflammatory process, and augmenting growth of normal pancreas to replace necrotic or apoptotic cell loss.
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Affiliation(s)
- Kevork K Kazanjian
- Department of Surgery, University of California, Los Angeles, California, USA
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Thomas RP, Hellmich MR, Townsend CM, Evers BM. Role of gastrointestinal hormones in the proliferation of normal and neoplastic tissues. Endocr Rev 2003; 24:571-99. [PMID: 14570743 DOI: 10.1210/er.2002-0028] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Gastrointestinal (GI) hormones are chemical messengers that regulate the physiological functions of the intestine and pancreas, including secretion, motility, absorption, and digestion. In addition to these well-defined physiological effects, GI hormones can stimulate proliferation of the nonneoplastic intestinal mucosa and pancreas. Furthermore, in an analogous fashion to breast and prostate cancer, certain GI cancers possess receptors for GI hormones; growth can be altered by administration of these hormones or by blocking their respective receptors. The GI hormones that affect proliferation, either stimulatory or inhibitory, include gastrin, cholecystokinin, gastrin-releasing peptide, neurotensin, peptide YY, glucagon-like peptide-2, and somatostatin. The effects of these peptides on normal and neoplastic GI tissues will be described. Also, future perspectives and potential therapeutic implications will be discussed.
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Affiliation(s)
- Robert P Thomas
- Department of Surgery, The University of Texas Medical Branch, Galveston, Texas 77555, USA
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Lambeir AM, Durinx C, Scharpé S, De Meester I. Dipeptidyl-peptidase IV from bench to bedside: an update on structural properties, functions, and clinical aspects of the enzyme DPP IV. Crit Rev Clin Lab Sci 2003; 40:209-94. [PMID: 12892317 DOI: 10.1080/713609354] [Citation(s) in RCA: 699] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Dipeptidyl-peptidase IV/CD26 (DPP IV) is a cell-surface protease belonging to the prolyloligopeptidase family. It selectively removes the N-terminal dipeptide from peptides with proline or alanine in the second position. Apart from its catalytic activity, it interacts with several proteins, for instance, adenosine deaminase, the HIV gp120 protein, fibronectin, collagen, the chemokine receptor CXCR4, and the tyrosine phosphatase CD45. DPP IV is expressed on a specific set of T lymphocytes, where it is up-regulated after activation. It is also expressed in a variety of tissues, primarily on endothelial and epithelial cells. A soluble form is present in plasma and other body fluids. DPP IV has been proposed as a diagnostic or prognostic marker for various tumors, hematological malignancies, immunological, inflammatory, psychoneuroendocrine disorders, and viral infections. DPP IV truncates many bioactive peptides of medical importance. It plays a role in glucose homeostasis through proteolytic inactivation of the incretins. DPP IV inhibitors improve glucose tolerance and pancreatic islet cell function in animal models of type 2 diabetes and in diabetic patients. The role of DPP IV/ CD26 within the immune system is a combination of its exopeptidase activity and its interactions with different molecules. This enables DPP IV/CD26 to serve as a co-stimulatory molecule to influence T cell activity and to modulate chemotaxis. DPP IV is also implicated in HIV-1 entry, malignant transformation, and tumor invasion.
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Affiliation(s)
- Anne-Marie Lambeir
- Department of Pharmaceutical Sciences, Laboratory of Medical Biochemistry, University of Antwerp, Universiteitsplein 1, Wilrijk, Belgium.
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Sáenz de Pipaón M, VanBeek RHT, Quero J, Pérez J, Wattimena DJL, Sauer PJJ. Effect of minimal enteral feeding on splanchnic uptake of leucine in the postabsorptive state in preterm infants. Pediatr Res 2003; 53:281-7. [PMID: 12538787 DOI: 10.1203/01.pdr.0000047519.22873.3f] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
We conducted a controlled, randomized trial to study the effect of minimal enteral feeding on leucine uptake by splanchnic tissues, as an indicator of maturation of these tissues, in preterm infants in the first week of life. Within a few hours after birth, while receiving only glucose, a primed constant infusion of [1-(13)C]-leucine was started and continued for 5 h via the nasogastric tube, whereas 5,5,5 D3-leucine was infused intravenously (for both tracers, priming dose 2 mg/kg, continuous infusion 2 mg/kg/h). Patients were thereafter randomized to receive solely parenteral nutrition (C), parenteral nutrition and 20 mL breast milk/kg/d (BM), or parenteral nutrition and 20 mL formula/kg/d (F). On d 7, the measurements were repeated, after discontinuing the oral intake for 5 h. Fourteen infants were included in group C, 12 in group BM, and 12 in group F. There was no difference in energy intake or nitrogen balance at any time. On d 1, plasma enrichment for the nasogastric tracer was lower than for the intravenous tracer for all three groups, both for leucine and for alpha-keto-isocaproic acid. On d 7, the enrichment for leucine and alpha-keto-isocaproic acid for the nasogastric tracer was lower than for the intravenous tracer for the groups BM and F (BM: 3.65 +/- 1.20 nasogastric versus 4.64 +/- 0.64 i.v.; F: 4.37 +/- 1.14 nasogastric versus 5.21 +/- 0.9 i.v.). In the control group, there was no difference between tracers. The lower plasma enrichment for the nasogastric tracer compared with the intravenous tracer suggests uptake of leucine by the splanchnic tissues. We conclude that minimal enteral feeding--even in low volumes of 20 mL/kg/d--increases the leucine uptake by the splanchnic tissue. We speculate that this reflects a higher protein synthesis of splanchnic tissues in the groups receiving enteral nutrition.
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Affiliation(s)
- Miguel Sáenz de Pipaón
- Neonatology Unit, La Paz University Hospital, Autónoma University of Madrid, Madrid, Spain.
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Lambeir AM, Durinx C, Scharpé S, De Meester I. Dipeptidyl-Peptidase IV from Bench to Bedside: An Update on Structural Properties, Functions, and Clinical Aspects of the Enzyme DPP IV. Crit Rev Clin Lab Sci 2003. [DOI: 10.1080/713609354/?{alert(1)}] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/30/2022]
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Abstract
Neuropeptide Y (NPY) family of hormones exhibits a wide spectrum of central and peripheral activities mediated by six G-protein coupled receptor subtypes denoted as Y1, Y2, Y3, Y4, Y5, and y6. Investigations to date have implicated NPY in the pathophysiology of a number of diseases including feeding disorders, seizures, anxiety, diabetes, hypertension, congestive heart failure and intestinal disorders. These observations suggest that long-acting, potent NPY receptor selective agonists and antagonists developed could be used to treat a variety of diseases. These possibilities are discussed in this paper.
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Affiliation(s)
- Ambikaipakan Balasubramaniam
- Division of Gastrointestinal Hormones, Department of Surgery, University of Cincinnati Medical Center, Cincinnati, OH 45267-0558, USA.
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Abstract
Peptide YY is an abundant distal gut hormone that may play a significant role in intestinal epithelial proliferation. Gut epithelial cells express specific receptors for PYY, PYY induces proliferation in intestinal cells in vivo and in vitro, and the Y1 receptor subtype couples to mitogenic signaling pathways. In addition to proposed physiologic effects on gut mucosal maintenance, PYY proliferative effects may be hypothesized to contribute to pathophysiologic consequences of stimulated growth.
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Affiliation(s)
- Peter J Mannon
- Mucosal Immunity Section, Laboratory of Clinical Investigation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA.
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Abstract
Peptide YY (PYY) is a naturally occurring gut hormone with mostly inhibitory actions on multiple tissue targets. PYY has been identified in several carcinoid tumors and a decreased expression of PYY may be relevant to the development and progression of colon adenocarcinoma. Treatment with PYY decreases growth in pancreatic and breast tumors, most likely through a reduction in intracellular cAMP. In cancer patients, PYY may also improve malnutrition that results from iatrogenic causes or cachexia associated with advanced disease. PYY plays a significant role in multiple aspects of cancer from regulation of cell growth to potential therapeutic applications.
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Affiliation(s)
- William W Tseng
- Northwestern University Medical School, Chicago, Illinois 60611, USA
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Chance WT, Sheriff S, Foley-Nelson T, Thomas I, Balasubramaniam A. Maintaining gut integrity during parenteral nutrition of tumor-bearing rats: effects of glucagon-like peptide 2. Nutr Cancer 2001; 37:215-22. [PMID: 11142096 DOI: 10.1207/s15327914nc372_15] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Maintaining tumor-bearing rats on total parenteral nutrition (TPN) for eight days significantly reduced mass, protein, and DNA in small intestine and colon. Coinfusion of glucagon-like peptide 2 (GLP-2) significantly increased each of these variables in the duodenum, jejunum, and ileum, but not in the colon. Histological analysis of tissue revealed normal mucosa thickness and villus height in the small intestine of GLP-2-treated rats, whereas non-treated rats maintained on TPN exhibited villus shortening and thinning of the mucosa. Compared with TPN alone, no significant effects of GLP-2 were noted on tumor growth, liver weight, or heart weight. Coinfusion of GLP-2 with TPN had no significant effect on TPN-associated immunosuppression, as measured by mitogen-induced proliferation of cultured splenocytes. Although translocation of bacteria to the mesenteric lymph nodes appeared to be reduced in GLP-2-treated rats, the difference between groups was not statistically significant. These results suggest that hormonal alterations may be more important than an absence of luminal nutrition in TPN-associated mucosa changes in tumor-bearing rats. Additionally, maintenance of gut integrity during TPN does not appear to be a sufficient condition for the avoidance of the negative sequelae associated with this route of supplemental nutrition.
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Affiliation(s)
- W T Chance
- Medical Research Service, Department of Veterans Affairs, Cincinnati, OH 45220, USA
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Kouris GJ, Liu Q, Rossi H, Djuricin G, Gattuso P, Nathan C, Weinstein RA, Prinz RA. The effect of glucagon-like peptide 2 on intestinal permeability and bacterial translocation in acute necrotizing pancreatitis. Am J Surg 2001; 181:571-5. [PMID: 11513789 DOI: 10.1016/s0002-9610(01)00635-3] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND Acute pancreatitis (AP) initiates a generalized inflammatory response that increases intestinal permeability and promotes bacterial translocation (BT). Impairment of the intestinal epithelial barrier is known to promote BT. Glucagon-like peptide 2 (GLP-2), a 33 residue peptide hormone, is a key regulator of the intestinal mucosa by stimulating epithelial growth. The purpose of this study was to determine whether GLP-2 decreases intestinal permeability and BT in AP. METHODS To examine whether GLP-2 can decrease intestinal permeability and thereby decrease BT in acute necrotizing pancreatitis, 34 male Sprague-Dawley rats (200 to 300 g) were studied. AP was induced in group I and group II by pressure injection of 3% taurocholate and trypsin into the common biliopancreatic duct (1 mg/kg of body weight). The potent analog to GLP-2 called ALX-0600 was utilized. Group I rats received GLP-2 analog (0.1 mg/kg, SQ, BID) and group II rats received a similar volume of normal saline as a placebo postoperatively for 3 days. Group III and group IV received GLP-2 analog and placebo, respectively. At 72 hours postoperatively, blood was drawn for culture of gram-negative organisms. Specimens from mesenteric lymph nodes (MLN), pancreas and peritoneum were harvested for culture of gram-negative bacteria. Intestinal resistance as defined by Ohm's law was determined using a modified Ussing chamber to measure transepithelial current at a fixed voltage. A point scoring system for five histologic features that include intestinal edema, inflammatory cellular infiltration, fat necrosis, parenchymal necrosis, and hemorrhage was used to evaluate the severity of pancreatitis. Specimens from MLN, pancreas, jejunum, and ileum were taken for pathology. RESULTS All group I and group II rats had AP. The average transepithelial resistance in group I was 82.8 Omega/cm(2) compared with 55.9 Omega/cm(2) in group II (P <0.01). Gram-negative BT to MLN, pancreas, and peritoneum was 80%, 0%, and 0%, respectively in group I compared with 100%, 30%, and 20% translocation in group II. CONCLUSION GLP-2 treatment significantly decreases intestinal permeability in acute pancreatitis.
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Affiliation(s)
- G J Kouris
- Department of General Surgery, Rush-Presbyterian-St. Luke's Medical Center, Cook County Hospital, Chicago, IL, USA
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Balasubramaniam A, Tao Z, Zhai W, Stein M, Sheriff S, Chance WT, Fischer JE, Eden PE, Taylor JE, Liu CD, McFadden DW, Voisin T, Roze C, Laburthe M. Structure-activity studies including a Psi(CH(2)-NH) scan of peptide YY (PYY) active site, PYY(22-36), for interaction with rat intestinal PYY receptors: development of analogues with potent in vivo activity in the intestine. J Med Chem 2000; 43:3420-7. [PMID: 10978189 DOI: 10.1021/jm000052z] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Peptide YY (PYY) is a gut hormone that inhibits secretion and promotes absorption and growth in the intestinal epithelium. We have performed structure-activity studies with the active site, N-alpha-Ac-PYY(22-36)-NH(2), for interaction with intestinal PYY receptors. Investigation of aromatic substitutions at position 27 resulted in analogues that exhibited potent in vitro antisecretory potencies with N-alpha-Ac-[Trp(27)]PYY(22-36)-NH(2) exhibiting even greater potency than intact PYY. In vivo studies in dogs revealed that this analogue also promoted intestinal absorption of water and electrolytes during continuous intravenous and intraluminal infusion. Investigations carried out to identify features that would enhance stability revealed that incorporation of Trp(30) increased affinity for PYY receptors. A "CH(2)-NH" scan revealed that incorporation of reduced bonds at position 28-29 or 35-36 imparted greater receptor affinity. In general, disubstituted analogues designed based on the results of single substitutions exhibited good receptor affinity with N-alpha-Ac-[Trp(27),CH(2)-NH(35-36)]PYY(22-36)-NH(2) having the greatest affinity (IC(50) = 0.28 nM). Conservative multiple substitutions with Nle-->Leu and Nva-->Val also imparted good affinity. An analogue designed to encompass most of the favored substitutions, N-alpha-Ac-[Nle(24,28),Trp(30),Nva(31), CH(2)-NH(35-36)]PYY(22-36)-NH(2), exhibited a proabsorptive effect in dogs comparable to, but longer lasting than, that of intact hormone. Selected analogues also exhibited good antisecretory potencies in rats with N-alpha-Ac-[Trp(30)]PYY(22-36)-NH(2) being even more potent than PYY. However, the potencies did not correlate well with the PYY receptor affinity or the proabsorptive potencies in dogs. These differences could be due to species effects and/or the involvement of multiple receptors and neuronal elements in controlling the in vivo activity of PYY compounds. PYY(22-36) analogues exhibited good affinity for neuronal Y2 receptors but poor affinity for Y1 receptors. Also, crucial analogues in this series hardly bound to Y4 and Y5 receptors. In summary, we have developed PYY(22-36) analogues which, via interacting with intestinal PYY receptors, promoted potent and long-lasting proabsorptive and antisecretory effects in in vivo models. These compounds or analogues based on them may have useful clinical application in treating malabsorptive disorders observed under a variety of conditions.
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Affiliation(s)
- A Balasubramaniam
- Division of Gastrointestinal Hormones, Department of Surgery, University of Cincinnati Medical Center, Cincinnati, Ohio 45267-0558, USA.
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Xiao Q, Boushey RP, Cino M, Drucker DJ, Brubaker PL. Circulating levels of glucagon-like peptide-2 in human subjects with inflammatory bowel disease. Am J Physiol Regul Integr Comp Physiol 2000; 278:R1057-63. [PMID: 10749795 DOI: 10.1152/ajpregu.2000.278.4.r1057] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Glucagon-like peptide-2 (GLP-2) is a recently characterized intestine-derived peptide that exerts trophic activity in the small and large intestine. Whether circulating levels of GLP-2 are perturbed in the setting of human inflammatory bowel disease (IBD) remains unknown. The circulating levels of bioactive GLP-2-(1-33) compared with its degradation product GLP-2-(3-33) were assessed using a combination of RIA and HPLC in normal and immunocompromised control human subjects and patients hospitalized for IBD. The activity of the enzyme dipeptidyl peptidase IV (DP IV), a key determinant of GLP-2-(1-33) degradation was also assessed in the plasma of normal controls and subjects with IBD. The circulating levels of bioactive GLP-2-(1-33) were increased in patients with either ulcerative colitis (UC) or Crohn's Disease (CD; to 229 +/- 65 and 317 +/- 89%, P < 0.05, of normal, respectively). Furthermore, the proportion of total immunoreactivity represented by intact GLP-2-(1-33), compared with GLP-2-(3-33), was increased from 43 +/- 3% in normal healthy controls to 61 +/- 6% (P < 0.01) and 59 +/- 2% (P < 0.01) in patients with UC and CD, respectively. The relative activity of plasma DP IV was significantly reduced in subjects with IBD compared with normal subjects (1.4 +/- 0.3 vs. 5.0 +/- 1.1 mU/ml, respectively; P < 0.05). These results suggest that patients with active IBD may undergo an adaptive response to intestinal injury by increasing the circulating levels of bioactive GLP-2-(1-33), facilitating enhanced repair of the intestinal mucosal epithelium in vivo.
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Affiliation(s)
- Q Xiao
- Department of Physiology, Mount Sinai Hospital and the Toronto General Hospital, Toronto M5G 2C4, Ontario, Canada M5S 1A8
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Mannon PJ, Kanungo A, Mannon RB, Ludwig KA. Peptide YY/neuropeptide Y Y1 receptor expression in the epithelium and mucosal nerves of the human colon. REGULATORY PEPTIDES 1999; 83:11-9. [PMID: 10498339 DOI: 10.1016/s0167-0115(99)00035-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
OBJECTIVES Peptide YY is an abundant distal gut hormone which regulates secretion, motility, and possibly epithelial proliferation in the gut. Though messenger RNA for the peptide YY Y1 receptor subtype occurs in the basal colonic crypts of humans, peptide YY receptors themselves have not been clearly localized within the adult human gastrointestinal tract. Using an antiserum directed against the C-terminus of the Y1 receptor we determined the actual extent of Y1 receptor protein expression in the human colon in order to identify areas targeted for peptide YY effects and suggest additional physiological roles for PYY in the human gut. RESULTS Y1 receptor protein expression was seen throughout the colonic epithelium along its basolateral aspect. There was an unexpected dense distribution of Y1 receptor immunoreactivity in varicose fibers within the mucosa. Staining was also noted in nerve fibers of the muscularis mucosae, in the submucous and myenteric plexuses, and in nerves in the muscularis propria. CONCLUSIONS Widespread distribution of Y1 receptors in the colonic epithelium and mucosal nerve fibers suggests diverse regulatory roles for peptide YY in modulating epithelial function as well as secretomotor reflexes in response to lumenal peptide YY-release signals.
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Affiliation(s)
- P J Mannon
- Department of Medicine, Durham Veterans Affairs Medical Center, NC 27710, USA.
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Abstract
The use of nutrients for pharmacotherapy is a recent advance in the treatment of gastrointestinal disorders or alterations of gut function and structure. Nutrients may have a direct effect on the gut, or may enhance the response to medications. Alternatively, pharmacologic agents may improve the absorption of nutrients. Potentially, pharmacotherapy may be an adjunct to the traditional approach used in the treatment of compromised patients.
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Affiliation(s)
- R D Rothstein
- Department of Medicine, University of Pennsylvania Health System, Philadelphia, USA
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Chance WT, Zhang X, Zuo L, Balasubramaniam A. Reduction of gut hypoplasia and cachexia in tumor-bearing rats maintained on total parenteral nutrition and treated with peptide YY and clenbuterol. Nutrition 1998; 14:502-7. [PMID: 9646290 DOI: 10.1016/s0899-9007(98)00038-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Prevention of gut hypoplasia associated with total parenteral nutrition (TPN) was investigated in 67 adult male Fisher 344 rats. Mass and protein content of the small intestine was reduced by 31% and 39%, respectively, after 7 d of TPN in tumor-bearing (TB) rats. Coinfusing peptide YY (PYY; 1 nmol.kg-1.h-1) and treating the rats with the anabolic beta-adrenergic agonist, clenbuterol (CLE; 2 mg.kg-1.d-1), resulted in significant savings in small intestine weight (26% increase) and protein (42% increase). Although the colon also exhibited a significant decrease in mass (31%), none of the treatment combinations were effective in this region of the gut. Histologic analysis of ileum suggested that the additive effects of PYY and CLE were due to differential effects of these compounds on mucosal and muscular tissues, respectively. This combination of treatments also resulted in significant savings (30% increase) in gastrocnemius protein, suggesting a reduction in the cachectic response. These results suggest that TPN-induced gut hypoplasia and cancer cachexia may be reduced by the proper combination of nutritional, hormonal, and pharmacologic treatments. In addition, the anabolic effects of various treatments may be additive to counteract TPN-induced gut atrophy.
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Affiliation(s)
- W T Chance
- Department of Surgery, University of Cincinnati Medical Center, Ohio 45267-0558, USA
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Abstract
Neuropeptide Y (NPY) is the most abundant peptide present in the mammalian central and peripheral nervous system. NPY exhibits a variety of potent central and peripheral effects including those on feeding, memory, blood pressure, cardiac contractility and intestinal secretions. Classical pharmacological studies have shown that NPY effects are mediated by four different receptor subtypes, Y-1, Y-1-like, Y-2, and Y-3. However, the existence of numerous atypical activities provide strong evidence for the occurrence of additional NPY receptor subtypes. Pharmacological studies have further been facilitated by the recent cloning and expression of Y-1, Y-2, Y-4 (PP-1) and Y-5 receptors. Moreover, the cloned Y-5 receptor has been suggested to be the long awaited Y-1-like receptor involved in feeding. Structure-activity studies have laid a good foundation towards the development of receptor selective compounds, and to date potent Y-1 selective peptide and nonpeptide antagonists have been developed. The need to clone numerous receptor subtypes and to develop receptor selective compounds for physiological and perhaps clinical use is expected to keep NPY research active for many years to come.
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Affiliation(s)
- A A Balasubramaniam
- Department of Surgery, University of Cincinnati Medical Center, Ohio 45267, USA. Ambi.bala@uc-edu
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