1
|
Jin Z, Choe HM, Lv S, Chang S, Yin X. Esophageal striated muscle hypertrophy and muscle fiber type transformation in MSTN knockout pigs. Transgenic Res 2022; 31:341-349. [DOI: 10.1007/s11248-022-00309-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 04/18/2022] [Indexed: 11/28/2022]
|
2
|
Tamura T, Okamoto H, Suzuki T, Nakanishi Y, Sugiyama D. Evaluation of the extent of damage to the esophageal wall caused by press-through package ingestion. PeerJ 2019; 7:e6763. [PMID: 31024769 PMCID: PMC6475578 DOI: 10.7717/peerj.6763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 03/11/2019] [Indexed: 11/22/2022] Open
Abstract
Press-through package (PTP) is the most common accidentally ingested foreign body in Japan. Accidental ingestion of PTP can result in esophageal damage. An approach for evaluating the risk of esophageal injury has not been established. Therefore, we used porcine esophageal tissue and silicone sheets to establish a method for assessing the risk of esophageal damage on accidental PTP ingestion. We pathologically evaluated porcine lower esophageal tissue using a scratch tester. Using porcine esophageal tissue, scratch tests were performed with 4 test objects and pathological damage was compared. It was assumed that each object was accidentally ingested. The objects were polyvinylidene chloride (PVDC)-coated polyvinyl chloride (PVC) PTP, soft PThPa, round PTP, and a disposable scalpel. The porcine esophagus was replaced with a silicon sheet, and an automatic friction machine was used for quantitative evaluation. The silicon sheet was scratched using HHS 2000 with 750-g load at 50 mm/min. We investigated the frictional force exerted on the surface for each of the objects. The degree of damage (depth) was the highest for the disposable scalpel, followed by PVDC-coated PVC PTP, while the degree of damage (depth) was the lowest for soft PThPa and round PTP. The mean frictional forces on the silicon sheet were 524.0 gf with PVDC-coated PTP, 323.5 gf with soft PThPa, 288.7 gf with round PTP, and 922.7 gf with the disposable scalpel. We developed approaches to qualitatively and quantitatively evaluate the risk of esophageal damage after accidental PTP ingestion. Our findings indicate that the risk of gastrointestinal damage after accidental PTP ingestion is low with soft PTP and round PTP.
Collapse
Affiliation(s)
- Takuya Tamura
- Department of Research and Development of Next Generation Medicine, Faculty of Medical Sciences, Kyushu University, Fukuoka, Japan.,Center for Clinical and Translational Research, Kyushu University Hospital, Fukuoka, Japan
| | - Hajime Okamoto
- Research & Development Center, Fujimori Kogyo CO., LTD., Yokohama, Japan
| | - Toyoaki Suzuki
- Research & Development Center, Fujimori Kogyo CO., LTD., Yokohama, Japan
| | - Yoichi Nakanishi
- Center for Clinical and Translational Research, Kyushu University Hospital, Fukuoka, Japan
| | - Daisuke Sugiyama
- Department of Research and Development of Next Generation Medicine, Faculty of Medical Sciences, Kyushu University, Fukuoka, Japan.,Center for Clinical and Translational Research, Kyushu University Hospital, Fukuoka, Japan.,Department of Clinical Study, Center for Advanced Medical Innovation, Kyushu University, Fukuoka, Japan
| |
Collapse
|
3
|
Saxena AK, Klimbacher G. Comparison of esophageal submucosal glands in experimental models for esophagus tissue engineering applications. Esophagus 2019; 16:77-84. [PMID: 30097829 DOI: 10.1007/s10388-018-0633-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 07/31/2018] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Esophagus tissue engineering holds promises to overcome the limitations of the presently employed esophageal replacement procedures. This study investigated 5 animal models for esophageal submucosal glands (ESMG) to identify models appropriate for regenerative medicine applications. Furthermore, this study aimed to measure geometric parameters of ESMG that could be utilized for fabrication of ESMG-specific scaffolds for esophagus tissue engineering applications. METHODS Ovine, avian, bovine, murine, and porcine esophagus were investigated using Hematoxylin-Eosin (HE), Periodic Acid Schiff (PAS), and Alcian Blue (AB), with AB applied in 3 pH levels (0.2, 1.0, and 2.5) to detect sulphated mucous. Celleye® (version F) was employed to gain parametric data on ESMGs (size, perimeter, distance to lumen, and acini concentration) necessary for scaffold fabrication. RESULTS Murine, bovine, and ovine esophagus were devoid of ESMG. Avian esophagus demonstrated sulphated acid mucous producing ESMGs with a holocrine secretion pattern, whereas sulphated acid and neutral mucous producing ESMGs with a merocrine secretion pattern were observed in porcine esophagus. Distance of ESMGs to lumen ranged from 127-340 μm (avian) to 916-983 μm (porcine). ESMGs comprised 35% (avian) to 45% (porcine) area of the submucosa. ESMG had an area of 125000 μm2 (avian) to 580000 μm2 (porcine). CONCLUSION Avian and porcine esophagus possesses ESMGs. However, porcine esophagus correlates with data available on human ESMGs. Geometric and parametric data obtained from ESMG are valuable for the fabrication of ESMG-specific scaffolds for esophagus tissue engineering using the hybrid construct approach.
Collapse
Affiliation(s)
- Amulya K Saxena
- Department of Pediatric Surgery, Chelsea Children's Hospital, Chelsea and Westminster NHS Fdn Trust, Imperial College London, London, UK.
| | - Guenther Klimbacher
- Department of General and Visceral Surgery, Kepler Universitatsklinikum, Linz, Austria
| |
Collapse
|
4
|
Abdulnour-Nakhoul S, Brown KL, Rabon EC, Al-Tawil Y, Islam MT, Schmieg JJ, Nakhoul NL. Cytoskeletal changes induced by allosteric modulators of calcium-sensing receptor in esophageal epithelial cells. Physiol Rep 2015; 3:3/11/e12616. [PMID: 26603452 PMCID: PMC4673644 DOI: 10.14814/phy2.12616] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The calcium-sensing receptor (CaSR), a G-protein-coupled receptor, plays a role in glandular and fluid secretion in the gastrointestinal tract, and regulates differentiation and proliferation of epithelial cells. We examined the expression of CaSR in normal and pathological conditions of human esophagus and investigated the effect of a CaSR agonist, cinacalcet (CCT), and antagonist, calhex (CHX), on cell growth and cell-cell junctional proteins in primary cultures of porcine stratified squamous esophageal epithelium. We used immunohistochemistry and Western analysis to monitor expression of CaSR and cell-cell adhesion molecules, and MTT assay to monitor cell proliferation in cultured esophageal cells. CCT treatment significantly reduced proliferation, changed the cell shape from polygonal to spindle-like, and caused redistribution of E-cadherin and β-catenin from the cell membrane to the cytoplasm. Furthermore, it reduced expression of β-catenin by 35% (P < 0.02) and increased expression of a proteolysis cleavage fragment of E-cadherin, Ecad/CFT2, by 2.3 folds (P < 0.01). On the other hand, CHX treatment enhanced cell proliferation by 27% (P < 0.01), increased the expression of p120-catenin by 24% (P < 0.04), and of Rho, a GTPase involved in cytoskeleton remodeling, by 18% (P < 0.03). In conclusion, CaSR is expressed in normal esophagus as well as in Barrett's, esophageal adenocarcinoma, squamous cell carcinoma, and eosinophilic esophagitis. Long-term activation of CaSR with CCT disrupted the cadherin-catenin complex, induced cytoskeletal remodeling, actin fiber formation, and redistribution of CaSR to the nuclear area. These changes indicate a significant and complex role of CaSR in epithelial remodeling and barrier function of esophageal cells.
Collapse
Affiliation(s)
- Solange Abdulnour-Nakhoul
- Medicine/Gastroenterology, Tulane Medical School, New Orleans, Louisiana South Louisiana Veterans Health Care System (SLVHCS), New Orleans, Louisiana
| | - Karen L Brown
- South Louisiana Veterans Health Care System (SLVHCS), New Orleans, Louisiana Medicine/Nephrology, Tulane Medical School, New Orleans, Louisiana
| | - Edd C Rabon
- South Louisiana Veterans Health Care System (SLVHCS), New Orleans, Louisiana
| | - Youhanna Al-Tawil
- Pediatric Gastroenterology and Nutrition-GI for Kids, East Tennessee Children's Hospital, Knoxville, Tennessee
| | - Mohammed T Islam
- South Louisiana Veterans Health Care System (SLVHCS), New Orleans, Louisiana Medicine/Nephrology, Tulane Medical School, New Orleans, Louisiana
| | - John J Schmieg
- Pathology, Tulane Medical School, New Orleans, Louisiana
| | - Nazih L Nakhoul
- South Louisiana Veterans Health Care System (SLVHCS), New Orleans, Louisiana Medicine/Nephrology, Tulane Medical School, New Orleans, Louisiana
| |
Collapse
|
5
|
Kapoor H, Lohani KR, Lee TH, Agrawal DK, Mittal SK. Animal Models of Barrett's Esophagus and Esophageal Adenocarcinoma-Past, Present, and Future. Clin Transl Sci 2015. [PMID: 26211420 DOI: 10.1111/cts.12304] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Esophageal adenocarcinoma is the fastest rising cancer in the United States. It develops from long-standing gastroesophageal reflux disease which affects >20% of the general population. It carries a very poor prognosis with 5-year survival <20%. The disease is known to sequentially progress from reflux esophagitis to a metaplastic precursor, Barrett's esophagus and then onto dysplasia and esophageal adenocarcinoma. However, only few patients with reflux develop Barrett's esophagus and only a minority of these turn malignant. The reason for this heterogeneity in clinical progression is unknown. To improve patient management, molecular changes which facilitate disease progression must be identified. Animal models can provide a comprehensive functional and anatomic platform for such a study. Rats and mice have been the most widely studied but disease homology with humans has been questioned. No animal model naturally simulates the inflammation to adenocarcinoma progression as in humans, with all models requiring surgical bypass or destruction of existing antireflux mechanisms. Valuable properties of individual models could be utilized to holistically evaluate disease progression. In this review paper, we critically examined the current animal models of Barrett's esophagus, their differences and homologies with human disease and how they have shaped our current understanding of Barrett's carcinogenesis.
Collapse
Affiliation(s)
- Harit Kapoor
- Department of Surgery and Center for Clinical & Translational Science, Creighton University School of Medicine, Omaha, Nebraska, USA
| | - Kush Raj Lohani
- Department of Surgery and Center for Clinical & Translational Science, Creighton University School of Medicine, Omaha, Nebraska, USA
| | - Tommy H Lee
- Department of Surgery and Center for Clinical & Translational Science, Creighton University School of Medicine, Omaha, Nebraska, USA
| | - Devendra K Agrawal
- Department of Surgery and Center for Clinical & Translational Science, Creighton University School of Medicine, Omaha, Nebraska, USA
| | - Sumeet K Mittal
- Department of Surgery and Center for Clinical & Translational Science, Creighton University School of Medicine, Omaha, Nebraska, USA
| |
Collapse
|
6
|
Raman V, MacGlaflin CE, Erkmen CP. Noninvasive Positive Pressure Ventilation Following Esophagectomy. Chest 2015; 147:356-361. [DOI: 10.1378/chest.14-0886] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023] Open
|
7
|
Petitpas F, Sichel F, Hébert B, Lagadu S, Beljean M, Pottier D, Laurentie M, Prevost V. Effects of alcohol consumption on biomarkers of oxidative damage to DNA and lipids in ethanol-fed pigs. ACTA ACUST UNITED AC 2011; 65:263-9. [PMID: 21945421 DOI: 10.1016/j.etp.2011.09.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Revised: 08/26/2011] [Accepted: 09/01/2011] [Indexed: 11/18/2022]
Abstract
Chronic alcohol consumption is known to result in tissue injury, particularly in the liver, and is considered a major risk factor for cancers of the upper respiratory tract. Here we assessed the oxidative effects of subchronic ethanol consumption on DNA and lipids by measuring biomarkers 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) and malondialdehyde (MDA), respectively. Physiological responses of pigs (n = 4) administered ethanol in drinking water for 39 days were compared with those of water-fed pigs (n = 4). Alcoholisation resulted in serum ethanol concentration of 1.90 g L(-1) and in a moderate but significant increase in alanine aminotransferase activity, an index of liver injury. However, between the alcoholised and control groups there were no significant differences in the levels of 8-oxodG (8-oxodG per 10(6) 2'deoxyguanosine) from leucocytes (2.52 ± 0.42 Vs 2.39 ± 0.34) or from target organs, liver, cardia and oesophagus. Serum MDA levels were also similar in ethanol-fed pigs (0.33 ± 0.04 μM) and controls (0.28 ± 0.03 μM). Interestingly, levels of 8-oxodG in cardia were positively correlated with those in oesophagus (Spearman correlation coefficient R = 1, P < 0.0001). Our results suggest that alcohol consumption may not cause oxidative damage to DNA and lipids as measured by 8-oxodG and MDA, respectively. The duration of alcoholisation and the potential alcohol-induced nutritional deficiency may be critical determinants of ethanol toxicity. Relevant biomarkers, such as factors involved in sensitization to ethanol-induced oxidative stress are required to better elucidate the relationship between alcohol consumption, oxidative stress and carcinogenesis.
Collapse
Affiliation(s)
- F Petitpas
- ANSES, Laboratoire de Fougères, BP 90203, 35302 Fougères cedex, France
| | | | | | | | | | | | | | | |
Collapse
|
8
|
Abdulnour-Nakhoul S, Nakhoul HN, Kalliny MI, Gyftopoulos A, Rabon E, Doetjes R, Brown K, Nakhoul NL. Ion transport mechanisms linked to bicarbonate secretion in the esophageal submucosal glands. Am J Physiol Regul Integr Comp Physiol 2011; 301:R83-96. [PMID: 21474426 DOI: 10.1152/ajpregu.00648.2010] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The esophageal submucosal glands (SMG) secrete HCO(3)(-) and mucus into the esophageal lumen, where they contribute to acid clearance and epithelial protection. This study characterized the ion transport mechanisms linked to HCO(3)(-) secretion in SMG. We localized ion transporters using immunofluorescence, and we examined their expression by RT-PCR and in situ hybridization. We measured HCO(3)(-) secretion by using pH stat and the isolated perfused esophagus. Using double labeling with Na(+)-K(+)-ATPase as a marker, we localized Na(+)-coupled bicarbonate transporter (NBCe1) and Cl(-)-HCO(3)(-) exchanger (SLC4A2/AE2) to the basolateral membrane of duct cells. Expression of cystic fibrosis transmembrane regulator channel (CFTR) was confirmed by immunofluorescence, RT-PCR, and in situ hybridization. We identified anion exchanger SLC26A6 at the ducts' luminal membrane and Na(+)-K(+)-2Cl(-) (NKCC1) at the basolateral membrane of mucous and duct cells. pH stat experiments showed that elevations in cAMP induced by forskolin or IBMX increased HCO(3)(-) secretion. Genistein, an activator of CFTR, which does not increase intracellular cAMP, also stimulated HCO(3)(-) secretion, whereas glibenclamide, a Cl(-) channel blocker, and bumetanide, a Na(+)-K(+)-2Cl(-) blocker, decreased it. CFTR(inh)-172, a specific CFTR channel blocker, inhibited basal HCO(3)(-) secretion as well as stimulation of HCO(3)(-) secretion by IBMX. This is the first report on the presence of CFTR channels in the esophagus. The role of CFTR in manifestations of esophageal disease in cystic fibrosis patients remains to be determined.
Collapse
Affiliation(s)
- Solange Abdulnour-Nakhoul
- Southeast Louisiana Veterans Health Care Network, Tulane University School of Medicine, New Orleans, Louisiana 70112, USA.
| | | | | | | | | | | | | | | |
Collapse
|
9
|
Hao J, Liu B, Yang CS, Chen X. Gastroesophageal reflux leads to esophageal cancer in a surgical model with mice. BMC Gastroenterol 2009; 9:59. [PMID: 19627616 PMCID: PMC2723127 DOI: 10.1186/1471-230x-9-59] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2008] [Accepted: 07/23/2009] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Esophago-gastroduodenal anastomosis with rats mimics the development of human Barrett's esophagus and esophageal adenocarcinoma by introducing mixed reflux of gastric and duodenal contents into the esophagus. However, use of this rat model for mechanistic and chemopreventive studies is limited due to lack of genetically modified rat strains. Therefore, a mouse model of esophageal adenocarcinoma is needed. METHODS We performed reflux surgery on wild-type, p53A135V transgenic, and INK4a/Arf+/- mice of A/J strain. Some mice were also treated with omeprazole (1,400 ppm in diet), iron (50 mg/kg/m, i.p.), or gastrectomy plus iron. Mouse esophagi were harvested at 20, 40 or 80 weeks after surgery for histopathological analysis. RESULTS At week 20, we observed metaplasia in wild-type mice (5%, 1/20) and p53A135V mice (5.3%, 1/19). At week 40, metaplasia was found in wild-type mice (16.2%, 6/37), p53A135V mice (4.8%, 2/42), and wild-type mice also receiving gastrectomy and iron (6.7%, 1/15). Esophageal squamous cell carcinoma developed in INK4a/Arf+/- mice (7.1%, 1/14), and wild-type mice receiving gastrectomy and iron (21.4%, 3/14). Among 13 wild-type mice which were given iron from week 40 to 80, twelve (92.3%) developed squamous cell carcinoma at week 80. None of these mice developed esophageal adenocarcinoma. CONCLUSION Surgically induced gastroesophageal reflux produced esophageal squamous cell carcinoma, but not esophageal adenocarcinoma, in mice. Dominant negative p53 mutation, heterozygous loss of INK4a/Arf, antacid treatment, iron supplementation, or gastrectomy failed to promote esophageal adenocarcinoma in these mice. Further studies are needed in order to develop a mouse model of esophageal adenocarcinoma.
Collapse
Affiliation(s)
- Jing Hao
- Department of Chemical Biology, Susan Lehman Cullman Laboratory for Cancer Research, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA.
| | | | | | | |
Collapse
|
10
|
Nelson L, Anderson S, Archibald AL, Rhind S, Lu ZH, Condie A, McIntyre N, Thompson J, Nenutil R, Vojtesek B, Whitelaw CBA, Little TJ, Hupp T. An animal model to evaluate the function and regulation of the adaptively evolving stress protein SEP53 in oesophageal bile damage responses. Cell Stress Chaperones 2008; 13:375-85. [PMID: 18465210 PMCID: PMC2673944 DOI: 10.1007/s12192-008-0037-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2007] [Revised: 03/04/2008] [Accepted: 03/12/2008] [Indexed: 01/19/2023] Open
Abstract
Squamous epithelium in mammals has evolved an atypical stress response involving down-regulation of the classic HSP70 protein and induction of sets of proteins including one named SEP53. This atypical stress response might be due to the unusual environmental pressures placed on squamous tissue. In fact, SEP53 plays a role as an anti-apoptotic factor in response to DNA damage induced by deoxycholic acid stresses implicated in oesophageal reflux disease. SEP53 also has a genetic signature characteristic of an adaptively and rapidly evolving gene, and this observation has been used to imply a role for SEP53 in immunity. Physiological models of squamous tissue are required to further define the regulation and function of SEP53. We examined whether porcine squamous epithelium would be a good model to study SEP53, since this animal suffers from a bile-reflux disease in squamous oesophageal tissue. We have (1) cloned and sequenced the porcine SEP53 locus from porcine bacterial artificial chromosome genomic DNA, (2) confirmed the strikingly divergent nature of the C-terminal portion of the SEP53 gene amongst mammals, (3) discovered that a function of the conserved N-terminal domain of the gene is to maintain cytoplasmic localisation, and (4) examined SEP53 expression in normal and diseased porcine pars oesophagea. SEP53 expression in porcine tissue was relatively confined to gastric squamous epithelium, consistent with its expression in normal human squamous epithelium. Immunohistochemical staining for SEP53 protein in normal and damaged pars oesophagea demonstrated significant stabilisation of SEP53 protein in the injured tissue. These results suggest that porcine squamous epithelium would be a robust physiological model to examine the evolution and function of the SEP53 stress pathway in modulating stress-induced responses in squamous tissue.
Collapse
Affiliation(s)
- Lenny Nelson
- CRUK p53 Signal Transduction Group, University of Edinburgh, South Crewe Road, Edinburgh, EH4 2XR UK
| | - Susan Anderson
- Division of Genomics and Genetics, Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Roslin, Midlothian, EH25 9PS UK
| | - Alan L. Archibald
- Division of Genomics and Genetics, Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Roslin, Midlothian, EH25 9PS UK
| | - Susan Rhind
- Division of Animal Health and Welfare, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Roslin, Midlothian, EH25 9RG UK
| | - Zen H. Lu
- Division of Genomics and Genetics, Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Roslin, Midlothian, EH25 9PS UK
| | - Alison Condie
- Wellcome Trust Clinical Research Facility, South Crewe Road, Edinburgh, EH4 2XU UK
| | - Neal McIntyre
- Division of Animal Health and Welfare, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Roslin, Midlothian, EH25 9RG UK
| | - Jill Thompson
- SAC Veterinary Services (Edinburgh), Bush Estate, Penicuik, Midlothian, EH26 0QE UK
| | | | | | - C. Bruce A. Whitelaw
- Division of Genomics and Genetics, Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Roslin, Midlothian, EH25 9PS UK
| | - Tom J. Little
- Institute of Evolutionary Biology, University of Edinburgh, School of Biology, Kings Buildings, EH9 3JT Edinburgh, UK
| | - Ted Hupp
- CRUK p53 Signal Transduction Group, University of Edinburgh, South Crewe Road, Edinburgh, EH4 2XR UK
| |
Collapse
|
11
|
Abdulnour-Nakhoul S, Nakhoul NL, Wheeler SA, Wang P, Swenson ER, Orlando RC. HCO3- secretion in the esophageal submucosal glands. Am J Physiol Gastrointest Liver Physiol 2005; 288:G736-44. [PMID: 15576627 DOI: 10.1152/ajpgi.00055.2004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The mammalian esophagus has the capacity to secrete a HCO(3)(-) and mucin-rich fluid in the esophageal lumen. These secretions originate from the submucosal glands (SMG) and can contribute to esophageal protection against refluxed gastric acid. The cellular mechanisms by which glandular cells achieve these secretions are largely unknown. To study this phenomenon, we used the pH-stat technique to measure luminal alkali secretion in an isolated, perfused pig esophagus preparation. Immunohistochemistry was used to localize receptors and transporters involved in HCO(3)(-) transport. The SMG-bearing esophagus was found to have significant basal alkali secretion, predominantly HCO(3)(-), which averaged 0.21 +/- 0.04 microeq.h(-1).cm(-2). This basal secretion was doubled when stimulated by carbachol but abolished by HCO(3)(-) or Cl(-) removal. Basal- and carbachol-stimulated secretions were also blocked by serosal application of atropine, pirenzipine, DIDS, methazolamide, and ethoxzolamide. The membrane-impermeable carbonic anhydrase inhibitor benzolamide, applied to the serosal bath, partially inhibited basal HCO(3)(-) secretion and blocked the stimulation by carbachol. Immunohistochemistry using antibodies to M(1) cholinergic receptor or carbonic anhydrase-II enzyme showed intense labeling of duct cells and serous demilunes but no labeling of mucous cells. Labeling with an antibody to Na(+)-(HCO(3)(-))(n) (rat kidney NBC) was positive in ducts and serous cells, whereas labeling for Cl(-)/HCO(3)(-) exchanger (AE2) was positive in duct cells but less pronounced in serous cells. These data indicate that duct cells and serous demilunes of SMG play a role in HCO(3)(-) secretion, a process that involves M(1) cholinergic receptor stimulation. HCO(3)(-) transport in these cells is dependent on cytosolic and serosal membrane-bound carbonic anhydrase. HCO(3)(-) secretion is also dependent on serosal Cl(-) and is mediated by DIDS-sensitive transporters, possibly NBC and AE2.
Collapse
Affiliation(s)
- Solange Abdulnour-Nakhoul
- The VA Medical Center, Attn: Research, Rm. 5F151, 1601 Perdido St., New Orleans, LA 70112-2699, USA.
| | | | | | | | | | | |
Collapse
|
12
|
Choy EPY, To TSS, Cho P, Benzie IFF, Choy CKM. Viability of porcine corneal epithelium ex vivo and effect of exposure to air: a pilot study for a dry eye model. Cornea 2004; 23:715-9. [PMID: 15448499 DOI: 10.1097/01.ico.0000127475.29551.56] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To explore the use of an ex vivo, in situ porcine cornea as a model for dry eye (exposure keratitis). METHODS Twenty-seven porcine eyes were obtained from freshly killed animals at the local abattoir. The viability of 9 corneas (control-baseline group) was assessed within 5 minutes after enucleation on site. A further 18 eyes were transported to the laboratory, where they were exposed to ambient conditions for 4 hours (experimental group A, 6 eyes), for 6 hours (experimental group B, 6 eyes), and for 4 hours with wetting with Dulbecco Phosphate-Buffered Saline every 5 minutes (exposure control group, 6 eyes). All corneas were assessed by trypan blue exclusion for cell viability. RESULTS The number of dead cells in the central region was significantly greater than those in the peripheral region (P < 0.05) in all groups. The number of dead cells in both corneal areas increased significantly (P < 0.05) in the experimental groups with time of exposure, but there was no significant increase in the exposure control group. CONCLUSION Preliminary data on the number of dead cells in porcine corneal epithelium after enucleation and the effect of exposure were obtained. It was found that after exposure to air, the corneal cells were maintained well by regular wetting, but there was progressively greater cell damage with exposure without wetting. These baseline data will be useful for the further development of the porcine dry eye model to investigate exposure keratitis.
Collapse
Affiliation(s)
- Emily Pik Yin Choy
- Department of Optometry and Radiography, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China.
| | | | | | | | | |
Collapse
|
13
|
Dixon J, Strugala V, Griffin SM, Welfare MR, Dettmar PW, Allen A, Pearson JP. Esophageal mucin: an adherent mucus gel barrier is absent in the normal esophagus but present in columnar-lined Barrett's esophagus. Am J Gastroenterol 2001; 96:2575-83. [PMID: 11569678 DOI: 10.1111/j.1572-0241.2001.04159.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVES The presence of a protective adherent mucus gel barrier against gastric reflux in the healthy esophagus is uncertain. The aim was to characterize the surface mucin composition and determine the extent of any adherent mucus gel layer on the normal esophagus, and compare this with that in Barrett's esophagus. METHODS Isolated surface mucins were characterized by density centrifugation, gel filtration chromatography, and chemical composition. Adherent surface mucus was visualized in situ on unfixed and cryostat sections of mucosa and biopsies using a method that preserves mucus layer thickness. RESULTS There was a complete absence of adherent mucus gel layers on normal human, pig, and rat esophagi. This was in contrast to the thick adherent mucous layer (median thickness = 100-200 microm) seen on the corresponding gastric mucosa. Small quantities of glycoprotein with a composition characteristic of a secretory mucin were isolated from the pig esophagus surface. The mucin, density range between 1.44 and 1.48 g x ml(-1), contained 80% carbohydrate and was rich in serine, threonine, and proline. The mucin fragmented into smaller glycoprotein units on proteolysis and partially on reduction. Cryostat sections from columnar-lined esophageal biopsies had a substantial adherent surface mucous layer (median thickness = 90 microm, interquartile range = 84-94 microm) staining for neutral mucins (gastric-type epithelium) and acidic mucins (intestinal metaplasia). CONCLUSIONS A secretory mucin, with an analysis distinct from that of gastric or salivary mucin, is present in very small quantities on the esophageal mucosa and in amounts insufficient to form an adherent gel layer. It is unlikely that mucus has a role in protecting the normal esophagus against reflux. However, an adherent mucous layer was observed over columnar-lined esophagus, and this may protect against reflux.
Collapse
Affiliation(s)
- J Dixon
- Department of Physiological Sciences and Medicine, Medical School, University of Newcastle Upon Tyne, United Kingdom
| | | | | | | | | | | | | |
Collapse
|
14
|
Abstract
Proline is unique among the 20 amino acids due to its cyclic structure. This specific conformation imposes many restrictions on the structural aspects of peptides and proteins and confers particular biological properties upon a wide range of physiologically important biomolecules. In order to adequately deal with such peptides, nature has developed a group of enzymes that recognise this residue specifically. These peptidases cover practically all situations where a proline residue might occur in a potential substrate. In this paper we endeavour to discuss these enzymes, particularly those responsible for peptide or protein hydrolysis at proline sites. We have detailed their discovery, biochemical attributes and substrate specificities and have provided information as to the methodology used to detect and manipulate their activities. We have also described the roles, or potential roles that these enzymes may play physiologically and the consequences of their dysfunction in varied disease states.
Collapse
Affiliation(s)
- D F Cunningham
- School of Biological Sciences, Dublin City University, Dublin, Ireland
| | | |
Collapse
|