Recovery of mucosal barrier function in ischemic porcine ileum and colon is stimulated by a novel agonist of the ClC-2 chloride channel, lubiprostone

2007 ◽  
Vol 292 (2) ◽  
pp. G647-G656 ◽  
Author(s):  
Adam J. Moeser ◽  
Prashant K. Nighot ◽  
Kory J. Engelke ◽  
Ryuji Ueno ◽  
Anthony T. Blikslager
Keyword(s):  
Tight Junctions ◽  
Barrier Function ◽  
Structural Changes ◽  
Ex Vivo ◽  
Short Circuit ◽  
Mucosal Barrier ◽  
Ileal Mucosa ◽  
Signaling Mechanism ◽  
Ussing Chambers ◽  
Mucosal Barrier Function

Previous studies utilizing an ex vivo porcine model of intestinal ischemic injury demonstrated that prostaglandin (PG)E2 stimulates repair of mucosal barrier function via a mechanism involving Cl− secretion and reductions in paracellular permeability. Further experiments revealed that the signaling mechanism for PGE2-induced mucosal recovery was mediated via type-2 Cl− channels (ClC-2). Therefore, the objective of the present study was to directly investigate the role of ClC-2 in mucosal repair by evaluating mucosal recovery in ischemia-injured intestinal mucosa treated with the selective ClC-2 agonist lubiprostone. Ischemia-injured porcine ileal mucosa was mounted in Ussing chambers, and short-circuit current ( Isc) and transepithelial electrical resistance (TER) were measured in response to lubiprostone. Application of 0.01–1 μM lubiprostone to ischemia-injured mucosa induced concentration-dependent increases in TER, with 1 μM lubiprostone stimulating a twofold increase in TER (ΔTER = 26 Ω·cm2; P < 0.01). However, lubiprostone (1 μM) stimulated higher elevations in TER despite lower Isc responses compared with the nonselective secretory agonist PGE2 (1 μM). Furthermore, lubiprostone significantly ( P < 0.05) reduced mucosal-to-serosal fluxes of 3H-labeled mannitol to levels comparable to those of normal control tissues and restored occludin localization to tight junctions. Activation of ClC-2 with the selective agonist lubiprostone stimulated elevations in TER and reductions in mannitol flux in ischemia-injured intestine associated with structural changes in tight junctions. Prostones such as lubiprostone may provide a selective and novel pharmacological mechanism of accelerating recovery of acutely injured intestine compared with the nonselective action of prostaglandins such as PGE2.

Stress signaling pathways activated by weaning mediate intestinal dysfunction in the pig

2007 ◽  
Vol 292 (1) ◽  
pp. G173-G181 ◽  
Author(s):  
Adam J. Moeser ◽  
Carin Vander Klok ◽  
Kathleen A. Ryan ◽  
Jenna G. Wooten ◽  
Dianne Little ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Barrier Function ◽  
Short Circuit ◽  
Mucosal Barrier ◽  
Intestinal Barrier Function ◽  
Stressful Event ◽  
Stress Signaling ◽  
Ussing Chambers ◽  
Mucosal Barrier Function ◽  
The Impact

Weaning in the piglet is a stressful event associated with gastrointestinal disorders and increased disease susceptibility. Although stress is thought to play a role in postweaning intestinal disease, the mechanisms by which stress influences intestinal pathophysiology in the weaned pig are not understood. The objectives of these experiments were to investigate the impact of weaning on gastrointestinal health in the pig and to assess the role of stress signaling pathways in this response. Nineteen-day-old pigs were weaned, and mucosal barrier function and ion transport were assessed in jejunal and colonic tissues mounted on Ussing chambers. Weaning caused marked disturbances in intestinal barrier function, as demonstrated by significant ( P < 0.01) reductions in transepithelial electrical resistance and increases in intestinal permeability to [3H]mannitol in both the jejunum and colon compared with intestinal tissues from age-matched, unweaned control pigs. Weaned intestinal tissues exhibited increased intestinal secretory activity, as demonstrated by elevated short-circuit current that was sensitive to treatment with tetrodotoxin and indomethacin, suggesting activation of enteric neural and prostaglandin synthesis pathways in weaned intestinal tissues. Western blot analyses of mucosal homogenates showed increased expression of corticotrophin-releasing factor (CRF) receptor 1 in the jejunum and colon of weaned intestinal tissues. Pretreatment of pigs with the CRF receptor antagonist α-helical CRF(9–41), which was injected intraperitoneally 30 min prior to weaning, abolished the stress-induced mucosal changes. Our results indicate that weaning stress induces mucosal dysfunction mediated by intestinal CRF receptors and activated by enteric nerves and prostanoid pathways.

Physiological concentrations of bile salts inhibit recovery of ischemic-injured porcine ileum

2004 ◽  
Vol 287 (2) ◽  
pp. G399-G407 ◽  
Author(s):  
Nigel B. Campbell ◽  
Craig G. Ruaux ◽  
Donnie E. Shifflett ◽  
Jöerg M. Steiner ◽  
David A. Williams ◽  
...  
Keyword(s):  
Barrier Function ◽  
Bile Salts ◽  
Deoxycholic Acid ◽  
Paracellular Permeability ◽  
Mucosal Barrier ◽  
Histological Evaluation ◽  
Ileal Mucosa ◽  
Ussing Chambers ◽  
Mucosal Barrier Function ◽  
Mannitol Flux

We have previously shown rapid in vitro recovery of barrier function in porcine ischemic-injured ileal mucosa, attributable principally to reductions in paracellular permeability. However, these experiments did not take into account the effects of luminal contents, such as bile salts. Therefore, the objective of this study was to evaluate the role of physiological concentrations of deoxycholic acid in recovery of mucosal barrier function. Porcine ileum was subjected to 45 min of ischemia, after which mucosa was mounted in Ussing chambers and exposed to varying concentrations of deoxycholic acid. The ischemic episode resulted in significant reductions in transepithelial electrical resistance (TER), which recovered to control levels of TER within 120 min, associated with significant reductions in mucosal-to-serosal 3H-labeled mannitol flux. However, treatment of ischemic-injured tissues with 10−5 M deoxycholic acid significantly inhibited recovery of TER with significant increases in mucosal-to-serosal 3H-labeled mannitol flux, whereas 10−6 M deoxycholic acid had no effect. Histological evaluation at 120 min revealed complete restitution regardless of treatment, indicating that the breakdown in barrier function was due to changes in paracellular permeability. Similar effects were noted with the application of 10−5 M taurodeoxycholic acid, and the effects of deoxycholic acid were reversed with application of the Ca2+-mobilizing agent thapsigargin. Deoxycholic acid at physiological concentrations significantly impairs recovery of epithelial barrier function by an effect on paracellular pathways, and these effects appear to be Ca2+ dependent.

Prostaglandin-mediated inhibition of Na+/H+ exchanger isoform 2 stimulates recovery of barrier function in ischemia-injured intestine

2006 ◽  
Vol 291 (5) ◽  
pp. G885-G894 ◽  
Author(s):  
Adam J. Moeser ◽  
Prashant K. Nighot ◽  
Kathleen A. Ryan ◽  
Jenna G. Wooten ◽  
Anthony T. Blikslager
Keyword(s):  
Barrier Function ◽  
Intestinal Ischemia ◽  
Short Circuit ◽  
Intestinal Barrier ◽  
Short Circuit Current ◽  
Selective Inhibition ◽  
Ileal Mucosa ◽  
Ussing Chambers ◽  
Nhe Isoforms

Prostaglandins stimulate repair of the ischemia-injured intestinal barrier in the porcine ileum through a mechanism involving cAMP-dependent Cl− secretion and inhibition of electroneutral Na+/H+ exchanger (NHE) activity. In the present study, we focused on the role of individual NHE isoforms in the recovery of barrier function. Ischemia-injured porcine ileal mucosa was mounted on Ussing chambers. Short-circuit current ( Isc), transepithelial electrical resistance (TER), and isotopic fluxes of 22Na were measured in response to PGE2 and selective inhibitors of epithelial NHE isoforms. Immunoassays were used to assess the expression of NHE isoforms. Forty-five minutes of intestinal ischemia resulted in a 45% reduction in TER ( P < 0.01). Near-complete restitution occurred within 60 min. Inhibition of NHE2 with HOE-694 (25 μM) added to the mucosal surface of the injured ileum stimulated significant elevations in TER, independent of changes in Isc and histological evidence of restitution. Pharmacological inhibition of NHE3 or NHE1 with mucosal S-3226 (20 μM) or serosal cariporide (25 μM), respectively, had no effect. Ischemia-injured tissues treated with mucosal S-3226 or HOE-694 exhibited equivalent reductions in mucosal-to-serosal fluxes of 22Na+ (by ∼35%) compared with nontreated ischemia-injured control tissues ( P < 0.05). Intestinal ischemia resulted in increased expression of the cytoplasmic NHE regulatory factor EBP50 in NHE2 but not in NHE3 immunoprecipitates. Selective inhibition of NHE2, and not NHE3, induces recovery of barrier function in the ischemia-injured intestine.

scholarly journals Early weaning stress impairs development of mucosal barrier function in the porcine intestine

2010 ◽  
Vol 298 (3) ◽  
pp. G352-G363 ◽  
Author(s):  
Feli Smith ◽  
Jessica E. Clark ◽  
Beth L. Overman ◽  
Christena C. Tozel ◽  
Jennifer H. Huang ◽  
...  
Keyword(s):  
Mast Cells ◽  
Barrier Function ◽  
Life Stress ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Mucosal Barrier ◽  
Early Weaning ◽  
Barrier Dysfunction ◽  
Weaned Pigs ◽  
Mucosal Barrier Function

Early life stress is a predisposing factor for the development of chronic intestinal disorders in adult life. Here, we show that stress associated with early weaning in pigs leads to impaired mucosal barrier function. Early weaning (15- to 21-day weaning age) resulted in sustained impairment in intestinal barrier function, as indicated by reductions in jejunal transepithelial electrical resistance and elevations in mucosal-to-serosal flux of paracellular probes [3H]mannitol and [14C]inulin measured at 5 and 9 wk of age, compared with that shown in late-weaned pigs (23- to 28-day weaning age). Elevated baseline short-circuit current was observed in jejunum from early-weaned pigs and was shown to be mediated via enhanced Cl− secretion. Jejunal barrier dysfunction in early-weaned pigs coincided with increased lamina propria immune cell density particularly mucosal mast cells. The mast cell stabilizer drug sodium cromoglycolate ameliorated barrier dysfunction and hypersecretion in early-weaned pigs, demonstrating an important role of mast cells. Furthermore, activation of mast cells ex vivo with c48/80 and corticotrophin-releasing factor (CRF) in pig jejunum mounted in Ussing chambers induced barrier dysfunction and elevations in short-circuit current that were inhibited with mast cell protease inhibitors. Experiments in which selective CRF receptor antagonists were administered to early-weaned pigs revealed that CRF receptor 1 (CRFr1) activation mediates barrier dysfunction and hypersecretion, whereas CRFr2 activation may be responsible for novel protective properties in the porcine intestine in response to early life stress.

Neonatal maternal separation predisposes adult rats to colonic barrier dysfunction in response to mild stress

2002 ◽  
Vol 283 (6) ◽  
pp. G1257-G1263 ◽  
Author(s):  
Johan D. Söderholm ◽  
Derrick A. Yates ◽  
Mélanie G. Gareau ◽  
Ping-Chang Yang ◽  
Glenda MacQueen ◽  
...  
Keyword(s):  
Maternal Separation ◽  
Acute Stress ◽  
Short Circuit ◽  
Mucosal Barrier ◽  
Transepithelial Transport ◽  
Mild Stress ◽  
Barrier Dysfunction ◽  
Adult Rats ◽  
Ussing Chambers ◽  
Mucosal Barrier Function

Intestinal dysfunction is related to stress and early life events, but the mechanisms are largely unknown. Our aim was to determine whether early trauma predisposes adult rats to intestinal mucosal dysfunction in response to stress. Neonatal Sprague-Dawley rats were individually separated from their mothers for 3 h/day at 4–21 days of age. Between days 80 and 90, separated and control rats were subjected to mild acute stress (30-min water avoidance) or sham stress. Mucosal barrier function and ion transport were assessed in colonic tissues mounted in Ussing chambers. Mild stress increased short-circuit current, conductance, and transepithelial transport of macromolecules in separated rats, while having minimal effects in controls. Pretreatment of the separated rats with a corticotropin-releasing hormone (CRH) antagonist, the peptide α-helical CRH(9–41) injected intraperitoneally 20 min before stress, abolished the stress-induced mucosal changes. Our results indicate that neonatal trauma can induce phenotypic changes in adulthood, including enhanced vulnerability of the gut mucosa to stress via mechanisms involving peripherally located CRH receptors.

Glucagon-Like Peptide-2 Improve Intestinal Mucosal Barrier Function in Aged Rats

2018 ◽  
Vol 22 (6) ◽  
pp. 731-738 ◽  
Author(s):  
Weiying Ren ◽  
Jiayu Wu ◽  
Li Li ◽  
Y. Lu ◽  
Y. Shao ◽  
...  
Keyword(s):  
Barrier Function ◽  
Mucosal Barrier ◽  
Aged Rats ◽  
Intestinal Mucosal Barrier ◽  
Mucosal Barrier Function ◽  
Glucagon Like Peptide

scholarly journals 191 Early weaning in pigs induces long-term alterations in intestinal nutrient transporter function and expression partially via beta adrenergic enteric neural receptors

2019 ◽  
Vol 97 (Supplement_2) ◽  
pp. 112-113
Author(s):  
Yihang Li ◽  
Karina Matos ◽  
Mrigendra Rajput ◽  
Adam James Moeser
Keyword(s):  
Adrenergic Receptor ◽  
Glucose Transporter ◽  
Short Circuit ◽  
Na Channel ◽  
Early Weaning ◽  
Ileal Mucosa ◽  
Ussing Chambers ◽  
New Findings ◽  
Nutrient Transporter

Abstract Early weaning (EW) has negative impacts on performance and health that persist from wean-to-finish. The mechanisms linking EW and lifetime performance reductions are poorly understood. The objective of this study was to investigate whether EW influences the long-term development of intestinal epithelial nutrient transporter function and expression and the potential mechanisms. Yorkshire gilts were split-weaned from their sows at 15 d (EW) or 28 d of age (Late Weaning; LW) and transferred to an on-site nursery room. All pigs received the same diets in a standard phase feeding program and were euthanized at 75 d of age. Mid-jejunum and distal ileum were mounted on Ussing chambers to evaluate Na+-dependent glucose and amino acid (AA) transporter function, measured as nutrient-induced changes in short circuit current (Isc). EW gilts exhibited reduced capacity for electrogenic transport of glucose (by ~30%; P < 0.05) and glutamate, glutamine, and alanine by (~ 30–35%; P < 0.05), compared with LW pigs. In contrast, jejunal and ileal lysine transporter function was upregulated (by 110% and 25%, respectively; P < 0.05) in EW pigs. Epithelial expression for glucose transporter (SGLT1) was reduced (P < 0.05) while glucose/fructose transporter (GLUT2), fructose transporter (GLUT5) and lysine transporters (B0AT1, CAT1, and ATB0, +) were enhanced in the EW jejunum. No differences observed in villus morphology between EW and LW pigs. Pretreatment of ileal mucosa on Ussing chambers with the Na+ channel blocker (Tetrodotoxin) or the β-adrenergic receptor blocker (Propranolol) augmented glucose, lysine and alanine transporter function in EW but not LW pigs. Together, these data show that EW in gilts induces lasting and divergent alterations in intestinal nutrient transporter function and expression which is mediated in part by the enteric nervous system and β-adrenergic receptor pathways. These new findings may explain why EW pigs exhibit lasting deleterious impacts on performance. Further mechanism-based investigations could reveal new targets for optimizing performance in EW pigs throughout the production lifespan.

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