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.

Neonatal maternal separation of rat pups results in abnormal cholinergic regulation of epithelial permeability

2007 ◽  
Vol 293 (1) ◽  
pp. G198-G203 ◽  
Author(s):  
Mélanie G. Gareau ◽  
Jennifer Jury ◽  
Mary H. Perdue
Keyword(s):  
Maternal Separation ◽  
Mucosal Barrier ◽  
Epithelial Barrier ◽  
Epithelial Permeability ◽  
Barrier Dysfunction ◽  
Adult Rats ◽  
Western Blots ◽  
Ussing Chambers ◽  
Rat Pups ◽  
Neonatal Maternal Separation

Neonatal maternal separation (MS) predisposes adult rats to develop stress-induced mucosal barrier dysfunction/visceral hypersensitivity and rat pups to develop colonic epithelial dysfunction. Our aim was to examine if enhanced epithelial permeability in such pups resulted from abnormal regulation by enteric nerves. Pups were separated from the dam for 3 h/day ( days 4– 20); nonseparated (NS) pups served as controls. On day 20, colonic tissues were removed and mounted in Ussing chambers. Horseradish peroxidase (HRP) flux was used to measure macromolecular permeability. HRP flux was increased in MS versus NS pups. The enhanced flux was inhibited by the cholinergic muscarinic antagonist atropine and the nicotinic antagonist hexamethonium. The cholinergic component was greater in tissues from MS versus NS pups, suggesting that increased cholinergic activity was responsible for the MS elevated permeability. Western blots and immunohistochemistry of colonic tissues demonstrated increased expression of choline acetyltransferase (ChAT) in MS pups, indicating greater synthesis of acetylcholine. Since a previous study indicated that corticotrophin-releasing factor (CRF) mediates barrier dysfunction in MS pups, we examined if the two pathways were linked. In MS tissues, nonselective CRF receptor antagonism inhibited the enhanced flux, and the addition of atropine did not produce further inhibition. Using selective receptor antagonists, we identified that CRF receptor 2 was involved in mediating this effect. These findings suggest that CRF, via CRF receptor 2, acts on cholinergic nerves to induce epithelial barrier dysfunction. Our study provides evidence that MS stimulates synthesis of acetylcholine, which, together with released CRF, creates a condition conducive to the development of epithelial barrier defects.

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.

Early maternal deprivation predisposes adult rats to colonic mucosal barrier dysfunction in response to mild stress

2001 ◽  
Vol 120 (5) ◽  
pp. A23-A24 ◽  
Author(s):  
Johan D. Soderholm ◽  
Derrick A. Yates ◽  
Glenda Macqueen ◽  
Mary H. Perdue
Keyword(s):  
Maternal Deprivation ◽  
Mucosal Barrier ◽  
Mild Stress ◽  
Barrier Dysfunction ◽  
Adult Rats

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.

Feeding induces lipid accumulation and increased Na+ transport in in vitro Necturus antrum

1990 ◽  
Vol 259 (6) ◽  
pp. G998-G1009
Author(s):  
M. J. Rutten ◽  
C. D. Moore ◽  
R. Delcore ◽  
L. Y. Cheung
Keyword(s):  
Electron Microscopy ◽  
Lipid Accumulation ◽  
Corn Oil ◽  
Short Circuit ◽  
Nile Red ◽  
Transepithelial Transport ◽  
Na Transport ◽  
Ussing Chambers ◽  
Lipid Granules

We investigated the effects of feeding on lipid accumulation and transepithelial transport using in vitro Necturus gastric antral mucosae. Antra from fed Necturi were examined for lipid accumulation using light, fluorescence, histochemical, and electron microscopy. Ussing chambers were used for measurement of potential difference (PD), transepithelial resistance (Rt), short-circuit current (Isc), and unidirectional fluxes of 22Na+ and [3H]mannitol. Light microscopy of antra from 2-day postfed animals showed many intracellular lipid granules in surface mucous epithelial cells. These granules could be distinguished from other intracellular organelles by their high affinity for osmium and the lipid fluorescent probe Nile red. Glycoprotein cytochemical staining showed these granules to be distinct from the epithelial cell mucous granules. Electron microscopy showed the lipid granules to be part of a membranous reticular network. Two-day postfed animals also had a approximately 3.5-fold increase in amiloride-sensitive Isc and PD, a decrease in Rt, and an increased luminal-to-serosal Na+ fluxes. Transepithelial [3H]mannitol fluxes were low and remained unchanged in both fasted and 2-day postfed animals. After 2 days of feeding, the PD and Isc began to decrease followed by a secondary increase in Rt. Feeding Necturi a corn oil diet did not induce the appearance of either cellular lipid or alterations in Isc but produced a transient increase in Rt. Our data show that feeding (goldfish) to Necturi causes an increase in both lipid accumulation and amiloride-sensitive Na+ transport in gastric antral cells.

scholarly journals Campylobacter concisus Impairs Sodium Absorption in Colonic Epithelium via ENaC Dysfunction and Claudin-8 Disruption

2020 ◽  
Vol 21 (2) ◽  
pp. 373 ◽  
Author(s):  
Praveen Kumar Nattramilarasu ◽  
Roland Bücker ◽  
Fábia Daniela Lobo de Sá ◽  
Anja Fromm ◽  
Oliver Nagel ◽  
...  
Keyword(s):  
Cell Model ◽  
Short Circuit ◽  
Intestinal Transport ◽  
Intestinal Lumen ◽  
Sodium Absorption ◽  
Epithelial Cell Line ◽  
Barrier Dysfunction ◽  
Campylobacter Concisus ◽  
Ussing Chambers ◽  
Ht 29

The epithelial sodium channel (ENaC) can increase the colonic absorptive capacity for salt and water. Campylobacter concisus is a common pathogenic epsilonproteobacterium, causing enteritis and diarrhea. It can induce barrier dysfunction in the intestine, but its influence on intestinal transport function is still unknown. Therefore, our study aimed to characterize C. concisus effects on ENaC using the HT-29/B6-GR/MR (epithelial cell line HT-29/B6 transfected with glucocorticoid and mineralocorticoid receptors) cell model and mouse colon. In Ussing chambers, C. concisus infection inhibited ENaC-dependent Na+ transport as indicated by a reduction in amiloride-sensitive short circuit current (−55%, n = 15, p < 0.001). This occurred via down-regulation of β- and γ-ENaC mRNA expression and ENaC ubiquitination due to extracellular signal-regulated kinase (ERK)1/2 activation, predicted by Ingenuity Pathway Analysis (IPA). In parallel, C. concisus reduced the expression of the sealing tight junction (TJ) protein claudin-8 and induced claudin-8 redistribution off the TJ domain of the enterocytes, which facilitates the back leakage of Na+ ions into the intestinal lumen. In conclusion, C. concisus caused ENaC dysfunction via interleukin-32-regulated ERK1/2, as well as claudin-8-dependent barrier dysfunction—both of which contribute to Na+ malabsorption and diarrhea.

Gastric surface cell function: potential difference and mucosal barrier

1984 ◽  
Vol 247 (1) ◽  
pp. G79-G87 ◽  
Author(s):  
J. M. McGreevy
Keyword(s):  
Cell Function ◽  
Cell Layer ◽  
Short Circuit ◽  
Potential Difference ◽  
Mucosal Barrier ◽  
Ussing Chambers ◽  
Fundic Mucosa ◽  
Surface Cell ◽  
Unidirectional Fluxes ◽  
Nutrient Solutions

Rabbit fundic mucosa mounted in Ussing chambers for 4 h developed morphological deterioration of the gastric glands (GG), while the surface epithelial cell layer (SEC) remained intact. Since the tissues maintained a steady-state potential difference (PD) and resistance (R), it seemed that the surface cells might be responsible for both the PD and the R. To test this hypothesis, segments of fundic mucosa were exposed to selective anoxia by bubbling the mucosal (anoxic SEC) or serosal (anoxic GG) nutrient solutions with N2 instead of O2. Control tissues received O2 into both nutrient solutions. SEC anoxia resulted in a PD and short-circuit current (Isc) of zero within 10 min; R fell by 60% within 2 h. GG anoxia caused no change in PD or R over 2 h. Unidirectional fluxes (J) of 36Cl did not diminish as expected in tissues with no PD or Isc. This persistent JCl in tissues with a PD of zero was investigated in tissues with anoxic SEC. Simultaneous unidirectional fluxes of 36Cl and [3H]mannitol were determined to identify the transcellular (JClcell) and paracellular (JClleak) components of JCl during SEC anoxia. Similar flux measurements were made in control tissues (no anoxia). In control tissues, the calculated JClcell correlated with Isc (r = 0.72, n = 44). In tissues with anoxic SEC, the JClcell was 0.05 +/- 0.4 (mean +/- SD, n = 44). This series of experiments suggests that the PD and mucosal barrier characteristics of rabbit gastric mucosa in Ussing chambers are functions of a healthy surface cell layer.

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