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Surinder K. Batra - One of the best experts on this subject based on the ideXlab platform.
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Genetically engineered mucin mouse models for inflammation and cancer
Cancer and Metastasis Reviews, 2015Co-Authors: Suhasini Joshi, Sushil Kumar, Sangeeta Bafna, Satyanarayana Rachagani, Kay-uwe Wagner, Maneesh Jain, Surinder K. BatraAbstract:Mucins are heavily O-glycosylated proteins primarily produced by glandular and ductal epithelial cells, either in membrane-tethered or secretory forms, for providing lubrication and protection from various exogenous and endogenous insults. However, recent studies have linked their aberrant overexpression with infection, inflammation, and cancer that underscores their importance in tissue homeostasis. In this review, we present current status of the existing mouse models that have been developed to gain insights into the functional role(s) of mucins under physiological and pathological conditions. Knockout mouse models for membrane-associated (Muc1 and Muc16) and secretory mucins (Muc2) have helped us to elucidate the role of mucins in providing effective and protective barrier functions against pathological threats, participation in disease progression, and improved our understanding of mucin interaction with biotic and abiotic environmental components. Emphasis is also given to available transgenic mouse models (MUC1 and MUC7), which has been exploited to understand the context-dependent regulation and therapeutic potential of human mucins during inflammation and cancer.
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Mucins in pancreatic cancer and its microenvironment
Nature Reviews Gastroenterology & Hepatology, 2013Co-Authors: Sukhwinder Kaur, Sushil Kumar, Navneet Momi, Aaron R. Sasson, Surinder K. BatraAbstract:Pancreatic cancer remains a lethal malignancy with poor prognosis. Here, the authors summarize emerging data on the role of mucins in the development and progression of pancreatic cancer and its microenvironment and discuss the diagnostic and therapeutic contributions of mucins for patients with pancreatic cancer. Pancreatic cancer remains a lethal malignancy with poor prognosis owing to therapeutic resistance, frequent recurrence and the absence of treatment strategies that specifically target the tumour and its supporting stroma. Deregulated cell-surface proteins drive neoplastic transformations and are envisioned to mediate crosstalk between the tumour and its microenvironment. Emerging studies have elaborated on the role of mucins in diverse biological functions, including enhanced tumorigenicity, invasiveness, metastasis and drug resistance through their characteristic O -linked and N -linked oligosaccharides (glycans), extended structures and unique domains. Multiple mucin domains differentially interact and regulate different components of the tumour microenvironment. This Review discusses: the expression pattern of various mucins in the pancreas under healthy, inflammatory, and cancerous conditions; the context-dependent attributes of mucins that differ under healthy and pathological conditions; the contribution of the tumour microenvironment in pancreatic cancer development and/or progression; diagnostic and/or prognostic efficacy of mucins; and mucin-based therapeutic strategies. Overall, this information should help to delineate the intricacies of pancreatic cancer by exploring the family of mucins, which, through various mechanisms in both tumour cells and the microenvironment, worsen disease outcome. Mucins, by virtue of their extended ectodomain, variety of domains and varied degree of glycosylation, act as multifaceted glycoproteins that have evolved convergently to protect the exposed surfaces of organisms Pancreatic cancer is characterized by the aberrant expression of both transmembrane and secretory mucins De novo expression of MUC4, MUC5AC, and MUC16 is observed in pancreatic cancer as early as pancreatic intraepithelial neoplasia and expression increases gradually with disease progression and subsequent metastasis Altered attributes of mucins are used by tumour cells to facilitate their growth, proliferation, interaction with the extracellular matrix or stromal cells and detachment from the primary tumour for invasion and metastasis CA19-9, the FDA-approved prognostic marker for pancreatic cancer, is a carbohydrate antigen (sialyl Lewis^a) present on the surface of MUC1, MUC16 and MUC5AC; MUC1-based therapies are in preclinical and clinical trials
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RETRACTED ARTICLE: Membrane-Bound Mucins and Mucin Terminal Glycans Expression in Idiopathic or Helicobacter pylori, NSAID Associated Peptic Ulcers
Digestive Diseases and Sciences, 2012Co-Authors: Doron Boltin, Marisa Halpern, Miriam Cohen, Zohar Levi, Alex Vilkin, Sara Morgenstern, Vahig Manugian, Erica St. Lawrence, Pascal Gagneux, Surinder K. BatraAbstract:Background The ratio of Helicobacter pylori /NSAID-negative gastric ulcers is increasing. Idiopathic gastric ulcers have unique clinical and endoscopic features, and are associated with more bleeding complications and a higher mortality. Alterations in gastric mucin expression and sialylation pattern may be important in ulcer pathogenesis. Aims The purpose of this study was to determine the expression pattern of membrane-bound mucins and side chain sugars in H. pylori associated-, NSAID-, and idiopathic-gastric ulcers. Methods We randomly selected 92 patients with H. pylori (group 1, n = 30), NSAID (group 2, n = 18), combined H. pylori and NSAID associated gastric ulcers (group 3, n = 24), and patients with idiopathic gastric ulcers (group 4, n = 20). Immunohistochemistry for T-cell CD4/CD8, MUC1, MUC4, MUC17, and ECA and SNA lectins staining was performed on sections from the ulcer margins. Inflammation score was assessed according to the Sydney system. Results Bleeding and mortality rates were significantly higher in group 4. CD4 positive T cell count was higher in H. pylori positive patients ( P = 0.009). Staining intensity of MUC17 was higher in group 1 than in group 4, foveola and glands alike, with 11.50 ± 3.47 versus 6.80 ± 4.02, and 9.61 ± 4.26 versus 7.59 ± 3.26, respectively ( P
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expression of MUC17 is regulated by hif1α mediated hypoxic responses and requires a methylation free hypoxia responsible element in pancreatic cancer
PLOS ONE, 2012Co-Authors: Sho Kitamoto, Michiyo Higashi, Seiya Yokoyama, Norishige Yamada, Surinder K. Batra, Shyuichiro Matsubara, Sonshin Takao, Suguru YonezawaAbstract:: MUC17 is a type 1 membrane-bound glycoprotein that is mainly expressed in the digestive tract. Recent studies have demonstrated that the aberrant overexpression of MUC17 is correlated with the malignant potential of pancreatic ductal adenocarcinomas (PDACs); however, the exact regulatory mechanism of MUC17 expression has yet to be identified. Here, we provide the first report of the MUC17 regulatory mechanism under hypoxia, an essential feature of the tumor microenvironment and a driving force of cancer progression. Our data revealed that MUC17 was significantly induced by hypoxic stimulation through a hypoxia-inducible factor 1α (HIF1α)-dependent pathway in some pancreatic cancer cells (e.g., AsPC1), whereas other pancreatic cancer cells (e.g., BxPC3) exhibited little response to hypoxia. Interestingly, these low-responsive cells have highly methylated CpG motifs within the hypoxia responsive element (HRE, 5'-RCGTG-3'), a binding site for HIF1α. Thus, we investigated the demethylation effects of CpG at HRE on the hypoxic induction of MUC17. Treatment of low-responsive cells with 5-aza-2'-deoxycytidine followed by additional hypoxic incubation resulted in the restoration of hypoxic MUC17 induction. Furthermore, DNA methylation of HRE in pancreatic tissues from patients with PDACs showed higher hypomethylation status as compared to those from non-cancerous tissues, and hypomethylation was also correlated with MUC17 mRNA expression. Taken together, these findings suggested that the HIF1α-mediated hypoxic signal pathway contributes to MUC17 expression, and DNA methylation of HRE could be a determinant of the hypoxic inducibility of MUC17 in pancreatic cancer cells.
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MUC17 protects intestinal epithelial cells from enteroinvasive e coli infection by promoting epithelial barrier integrity
American Journal of Physiology-gastrointestinal and Liver Physiology, 2011Co-Authors: Silvia Restalenert, Surinder K. Batra, Samuel B HoAbstract:The membrane-bound mucin MUC17 (mouse homolog Muc3) is highly expressed on the apical surface of intestinal epithelia and is thought to play a role in epithelial restitution and protection. Therefore, we hypothesized that MUC17 has a role in protection of the intestinal mucosa against luminal pathogens. Human intestinal cell lines were transfected by electroporation (Caco-2 and HT 29/19A) and by retroviral expression vector (LS174T, a cell line with high levels of MUC17 expression) using MUC17 siRNA. Transepithelial electrical resistance, permeability, tight-junction protein expression, adhesion, and invasion in response to enteroinvasive Escherichia coli (EIEC) were measured in all cell lines. In some experiments, the effect of the addition of exogenous purified crude mucin or recombinant Muc3 cysteine-rich domain protein (Muc3 CRD1-L-CRD2) as preventative or protective treatment was tested. Reduction of endogenous MUC17 is associated with increased permeability, inducible nitric oxide synthase and cyclooxygenase 2 induction, and enhanced bacterial invasion in response to EIEC exposure. Bacterial adhesion is not affected. Exogenous mucin (Muc3) and recombinant Muc3CRD treatment had a small but significant effect in attenuating the effects of EIEC infection. In conclusion, these data suggest that both native and exogenous MUC17 play a role in attachment and invasion of EIEC in colonic cell lines and in maintaining epithelial barrier function.
Gunnar C Hansson - One of the best experts on this subject based on the ideXlab platform.
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the human transmembrane mucin MUC17 responds to tnfα by increased presentation at the plasma membrane
Biochemical Journal, 2019Co-Authors: Hannah Schneider, Thaher Pelaseyed, Evelin Berger, Brendan Dolan, Beatriz Martinezabad, Liisa Arike, Gunnar C HanssonAbstract:Transmembrane mucin MUC17 is an integral part of the glycocalyx as it covers the brush border membrane of small intestinal enterocytes and presents an extended O-glycosylated mucin domain to the intestinal lumen. Here, we identified two unknown phosphorylated serine residues, S4428 and S4492, in the cytoplasmic tail of human MUC17. We have previously demonstrated that MUC17 is anchored to the apical membrane domain via an interaction with the scaffolding protein PDZK1. S4492, localized in the C-terminal PDZ binding motif of MUC17, was mutated to generate phosphomimetic and phosphodeficient variants of MUC17. Using Caco-2 cells as a model system, we found that induction of an inflammatory state by long-term stimulation with the proinflammatory cytokine TNFα resulted in an increase of MUC17 protein levels and enhanced insertion of MUC17 and its two phospho-variants into apical membranes. Up-regulation and apical insertion of MUC17 was followed by shedding of MUC17-containing vesicles. Transmembrane mucins have previously been shown to play a role in the prevention of bacterial colonization by acting as sheddable decoys for encroaching bacteria. Overexpression and increased presentation at the plasma membrane of wild-type MUC17 and its phosphodeficient variant MUC17 S-4492A protected Caco-2 cells against adhesion of enteropathogenic Escherichia coli, indicating that C-terminal phosphorylation of MUC17 may play a functional role in epithelial cell protection. We propose a new function for MUC17 in inflammation, where MUC17 acts as a second line of defense by preventing attachment of bacteria to the epithelial cell glycocalyx in the small intestine.
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carbachol induced MUC17 endocytosis is concomitant with nhe3 internalization and cftr membrane recruitment in enterocytes
American Journal of Physiology-cell Physiology, 2013Co-Authors: Thaher Pelaseyed, Jenny K Gustafsson, Ida J Gustafsson, Anna Ermund, Gunnar C HanssonAbstract:We have reported that transmembrane mucin MUC17 binds PDZ protein PDZK1, which retains MUC17 apically in enterocytes. MUC17 and transmembrane mucins MUC3 and MUC12 are suggested to build the entero...
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CFTR anion channel modulates expression of human transmembrane mucin MUC3 through the PDZ protein GOPC.
Journal of cell science, 2011Co-Authors: Thaher Pelaseyed, Gunnar C HanssonAbstract:The transmembrane mucins in the enterocyte are type 1 transmembrane proteins with long and rigid mucin domains, rich in proline, threonine and serine residues that carry numerous O-glycans. Three of these mucins, MUC3, MUC12 and MUC17 are unique in harboring C-terminal class I PDZ motifs, making them suitable ligands for PDZ proteins. A screening of 123 different human PDZ domains for binding to MUC3 identified a strong interaction with the PDZ protein GOPC (Golgi-associated PDZ and coiled-coil motif-containing protein). This interaction was mediated by the C-terminal PDZ motif of MUC3, binding to the single GOPC PDZ domain. GOPC is also a binding partner for cystic fibrosis transmembrane conductance regulator (CFTR) that directs CFTR for degradation. Overexpression of GOPC downregulated the total levels of MUC3, an effect that was reversed by introducing CFTR. The results suggest that CFTR and MUC3 compete for binding to GOPC, which in turn can regulate levels of these two proteins. For the first time a direct coupling between mucins and the CFTR channel is demonstrated, a finding that will shed further light on the still poorly understood relationship between cystic fibrosis and the mucus phenotype of this disease.
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the c terminus of the transmembrane mucin MUC17 binds to the scaffold protein pdzk1 that stably localizes it to the enterocyte apical membrane in the small intestine
Biochemical Journal, 2008Co-Authors: Emily K Malmberg, Thaher Pelaseyed, Asa C Petersson, Ursula Seidler, Hugo R De Jonge, John R Riordan, Gunnar C HanssonAbstract:The membrane-bound mucins have a heavily O-glycosylated extracellular domain, a single-pass membrane domain and a short cytoplasmic tail. Three of the membrane-bound mucins, MUC3, MUC12 and MUC17, are clustered on chromosome 7 and found in the gastrointestinal tract. These mucins have C-terminal sequences typical of PDZ-domain-binding proteins. To identify PDZ proteins that are able to interact with the mucins, we screened PDZ domain arrays using YFP (yellow fluorescent protein)-tagged proteins. MUC17 exhibited a strong binding to PDZK1 (PDZ domain containing 1), whereas the binding to NHERF1 (Na + /H + -exchanger regulatory factor 1) was weak. Furthermore, we showed weak binding of MUC12 to PDZK1, NHERF1 and NHERF2. GST (glutathione transferase) pull-down experiments confirmed that the C-terminal tail of MUC17 co-precipitates with the scaffold protein PDZK1 as identified by MS. This was mediated through the C-terminal PDZ-interaction site in MUC17, which was capable of binding to three of the four PDZ domains in PDZK1. Immunostaining of wild-type or Pdzk1 −/− mouse jejunum with an antiserum against Muc3(17), the mouse orthologue of human MUC17, revealed strong brush-border membrane staining in the wild-type mice compared with an intracellular Muc3(17) staining in the Pdzk1 −/− mice. This suggests that Pdzk1 plays a specific role in stabilizing Muc3(17) in the apical membrane of small intestinal enterocytes.
Thaher Pelaseyed - One of the best experts on this subject based on the ideXlab platform.
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the human transmembrane mucin MUC17 responds to tnfα by increased presentation at the plasma membrane
Biochemical Journal, 2019Co-Authors: Hannah Schneider, Thaher Pelaseyed, Evelin Berger, Brendan Dolan, Beatriz Martinezabad, Liisa Arike, Gunnar C HanssonAbstract:Transmembrane mucin MUC17 is an integral part of the glycocalyx as it covers the brush border membrane of small intestinal enterocytes and presents an extended O-glycosylated mucin domain to the intestinal lumen. Here, we identified two unknown phosphorylated serine residues, S4428 and S4492, in the cytoplasmic tail of human MUC17. We have previously demonstrated that MUC17 is anchored to the apical membrane domain via an interaction with the scaffolding protein PDZK1. S4492, localized in the C-terminal PDZ binding motif of MUC17, was mutated to generate phosphomimetic and phosphodeficient variants of MUC17. Using Caco-2 cells as a model system, we found that induction of an inflammatory state by long-term stimulation with the proinflammatory cytokine TNFα resulted in an increase of MUC17 protein levels and enhanced insertion of MUC17 and its two phospho-variants into apical membranes. Up-regulation and apical insertion of MUC17 was followed by shedding of MUC17-containing vesicles. Transmembrane mucins have previously been shown to play a role in the prevention of bacterial colonization by acting as sheddable decoys for encroaching bacteria. Overexpression and increased presentation at the plasma membrane of wild-type MUC17 and its phosphodeficient variant MUC17 S-4492A protected Caco-2 cells against adhesion of enteropathogenic Escherichia coli, indicating that C-terminal phosphorylation of MUC17 may play a functional role in epithelial cell protection. We propose a new function for MUC17 in inflammation, where MUC17 acts as a second line of defense by preventing attachment of bacteria to the epithelial cell glycocalyx in the small intestine.
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Study of mucin turnover in the small intestine by in vivo labeling
Scientific Reports, 2018Co-Authors: Hannah Schneider, Thaher Pelaseyed, Frida Svensson, Malin E. V. JohanssonAbstract:Mucins are highly glycosylated proteins which protect the epithelium. In the small intestine, the goblet cell-secreted Muc2 mucin constitutes the main component of the loose mucus layer that traps luminal material. The transmembrane mucin MUC17 forms part of the carbohydrate-rich glycocalyx covering intestinal epithelial cells. Our study aimed at investigating the turnover of these mucins in the small intestine by using in vivo labeling of O-glycans with N-azidoacetylgalactosamine. Mice were injected intraperitoneally and sacrificed every hour up to 12 hours and at 24 hours. Samples were fixed with preservation of the mucus layer and stained for Muc2 and MUC17. Turnover of Muc2 was slower in goblet cells of the crypts compared to goblet cells along the villi. MUC17 showed stable expression over time at the plasma membrane on villi tips, in crypts and at crypt openings. In conclusion, we have identified different subtypes of goblet cells based on their rate of mucin biosynthesis and secretion. In order to protect the intestinal epithelium from chemical and bacterial hazards, fast and frequent renewal of the secreted mucus layer in the villi area is combined with massive secretion of stored Muc2 from goblet cells in the upper crypt.
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the mucus and mucins of the goblet cells and enterocytes provide the first defense line of the gastrointestinal tract and interact with the immune system
Immunological Reviews, 2014Co-Authors: Thaher Pelaseyed, Jenny K Gustafsson, Anna Ermund, Joakim H Bergstrom, George M H Birchenough, Andre Schutte, Sjoerd Van Der Post, Frida Svensson, Ana M Rodriguezpineiro, Elisabeth E L NystromAbstract:The gastrointestinal tract is covered by mucus that has different properties in the stomach, small intestine and colon. The large highly glycosylated gel-forming mucins MUC2 and MUC5AC are the major components of the mucus in the intestine and stomach, respectively. In the small intestine mucus limits the number of bacteria that can reach the epithelium and the Peyer’s patches. In the large intestine the inner mucus layer separates the commensal bacteria from the host epithelium. The outer colonic mucus layer is the natural habitat for the commensal bacteria. The intestinal goblet cells not only secrete the MUC2 mucin, but also a number of typical mucus components: CLCA1, FCGBP, AGR2, ZG16, and TFF3. The goblet cells have recently been shown to have a novel gate-keeping role for the presentation of oral antigens to the immune system. Goblet cells deliver small intestinal luminal material to the lamina propria dendritic cells of the tolerogenic CD103+-type. In addition to the gel forming mucins, the transmembrane mucins MUC3, MUC12 and MUC17 form the enterocyte glycocalyx that can reach about a micrometer out from the brush border. The MUC17 mucin can shuttle from a surface to an intracellular vesicle localization suggesting that enterocytes might control and report epithelial microbial challenge. There is not only communication from the epithelial cells to the immune system, but also in the opposite direction. One example of this is IL10 that can affect and improve the properties of the inner colonic mucus layer. The mucus and epithelial cells of the gastrointestinal tract are the primary gate keepers and controllers of bacterial interactions with the host immune system, but our understanding of this relationship is still in its infancy.
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carbachol induced MUC17 endocytosis is concomitant with nhe3 internalization and cftr membrane recruitment in enterocytes
American Journal of Physiology-cell Physiology, 2013Co-Authors: Thaher Pelaseyed, Jenny K Gustafsson, Ida J Gustafsson, Anna Ermund, Gunnar C HanssonAbstract:We have reported that transmembrane mucin MUC17 binds PDZ protein PDZK1, which retains MUC17 apically in enterocytes. MUC17 and transmembrane mucins MUC3 and MUC12 are suggested to build the entero...
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CFTR anion channel modulates expression of human transmembrane mucin MUC3 through the PDZ protein GOPC.
Journal of cell science, 2011Co-Authors: Thaher Pelaseyed, Gunnar C HanssonAbstract:The transmembrane mucins in the enterocyte are type 1 transmembrane proteins with long and rigid mucin domains, rich in proline, threonine and serine residues that carry numerous O-glycans. Three of these mucins, MUC3, MUC12 and MUC17 are unique in harboring C-terminal class I PDZ motifs, making them suitable ligands for PDZ proteins. A screening of 123 different human PDZ domains for binding to MUC3 identified a strong interaction with the PDZ protein GOPC (Golgi-associated PDZ and coiled-coil motif-containing protein). This interaction was mediated by the C-terminal PDZ motif of MUC3, binding to the single GOPC PDZ domain. GOPC is also a binding partner for cystic fibrosis transmembrane conductance regulator (CFTR) that directs CFTR for degradation. Overexpression of GOPC downregulated the total levels of MUC3, an effect that was reversed by introducing CFTR. The results suggest that CFTR and MUC3 compete for binding to GOPC, which in turn can regulate levels of these two proteins. For the first time a direct coupling between mucins and the CFTR channel is demonstrated, a finding that will shed further light on the still poorly understood relationship between cystic fibrosis and the mucus phenotype of this disease.
Samuel B Ho - One of the best experts on this subject based on the ideXlab platform.
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MUC17 protects intestinal epithelial cells from enteroinvasive e coli infection by promoting epithelial barrier integrity
American Journal of Physiology-gastrointestinal and Liver Physiology, 2011Co-Authors: Silvia Restalenert, Surinder K. Batra, Samuel B HoAbstract:The membrane-bound mucin MUC17 (mouse homolog Muc3) is highly expressed on the apical surface of intestinal epithelia and is thought to play a role in epithelial restitution and protection. Therefore, we hypothesized that MUC17 has a role in protection of the intestinal mucosa against luminal pathogens. Human intestinal cell lines were transfected by electroporation (Caco-2 and HT 29/19A) and by retroviral expression vector (LS174T, a cell line with high levels of MUC17 expression) using MUC17 siRNA. Transepithelial electrical resistance, permeability, tight-junction protein expression, adhesion, and invasion in response to enteroinvasive Escherichia coli (EIEC) were measured in all cell lines. In some experiments, the effect of the addition of exogenous purified crude mucin or recombinant Muc3 cysteine-rich domain protein (Muc3 CRD1-L-CRD2) as preventative or protective treatment was tested. Reduction of endogenous MUC17 is associated with increased permeability, inducible nitric oxide synthase and cyclooxygenase 2 induction, and enhanced bacterial invasion in response to EIEC exposure. Bacterial adhesion is not affected. Exogenous mucin (Muc3) and recombinant Muc3CRD treatment had a small but significant effect in attenuating the effects of EIEC infection. In conclusion, these data suggest that both native and exogenous MUC17 play a role in attachment and invasion of EIEC in colonic cell lines and in maintaining epithelial barrier function.
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Intestinal Goblet Cells and Mucins in Health and Disease: Recent Insights and Progress
Current Gastroenterology Reports, 2010Co-Authors: Samuel B HoAbstract:The mucus layer coating the gastrointestinal tract is the front line of innate host defense, largely because of the secretory products of intestinal goblet cells. Goblet cells synthesize secretory mucin glycoproteins ( MUC2 ) and bioactive molecules such as epithelial membrane-bound mucins ( MUC1, MUC3, MUC17 ), trefoil factor peptides (TFF), resistin-like molecule β (RELMβ), and Fc-γ binding protein (Fcgbp). The MUC2 mucin protein forms trimers by disulfide bonding in cysteine-rich amino terminal von Willebrand factor (vWF) domains, coupled with crosslinking provided by TFF and Fcgbp proteins with MUC2 vWF domains, resulting in a highly viscous extracellular layer. Colonization by commensal intestinal microbiota is limited to an outer “loose” mucus layer, and interacts with the diverse oligosaccharides of mucin glycoproteins, whereas an “inner” adherent mucus layer is largely devoid of bacteria. Defective mucus layers resulting from lack of MUC2 mucin, mutated Muc2 mucin vWF domains, or from deletion of core mucin glycosyltransferase enzymes in mice result in increased bacterial adhesion to the surface epithelium, increased intestinal permeability, and enhanced susceptibility to colitis caused by dextran sodium sulfate. Changes in mucin gene expression and mucin glycan structures occur in cancers of the intestine, contributing to diverse biologic properties involved in the development and progression of cancer. Further research is needed on identification and functional significance of various components of mucus layers and the complex interactions among mucus layers, microbiota, epithelial cells, and the underlying innate and adaptive immunity. Further elucidation of the regulatory mechanisms involved in mucin changes in cancer and inflammation may lead to the development of novel therapeutic approaches.
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expression of intestinal MUC17 membrane bound mucin in inflammatory and neoplastic diseases of the colon
Journal of Clinical Pathology, 2010Co-Authors: Shantibhusan Senapati, Sukhwinder Kaur, Samuel B Ho, Poonam Sharma, Subhankar Chakraborty, Gloria A Niehans, Surinder K. BatraAbstract:Aim To determine the cellular location and expression of MUC17 mucin in specimens of normal, inflamed and neoplastic colon. Methods Immunohistochemical analysis of human surgical resection specimens (n=106) was performed with a specific antibody to the MUC17 apomucin protein. A semi-quantitative scoring system was used to measure MUC17 expression. In various colon cancer cell lines, the MUC17 expression was examined by immunoblot analysis and normal RT-PCR. Results MUC17 was highly expressed on the surface epithelium and crypts of colonic mucosa. In contrast, the expression of MUC17 was significantly decreased in colonic mucosa of chronic ulcerative colitis (p Conclusion Results indicate that the potential protective effects of this membrane-bound mucin are primarily or secondarily diminished in inflammatory and neoplastic conditions. Further research is needed to determine the specific role of MUC17 in the pathogenesis of these conditions.
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human intestinal MUC17 mucin augments intestinal cell restitution and enhances healing of experimental colitis
The International Journal of Biochemistry & Cell Biology, 2010Co-Authors: Wade M Junker, Satyanarayana Rachagani, Surinder K. Batra, Robert L Heinrikson, Laurie L Shekels, Samuel B HoAbstract:Abstract The membrane-bound mucins, MUC17 (human) and Muc3 (mouse), are highly expressed on the apical surface of intestinal epithelia and are thought to be cytoprotective. The extracellular regions of these mucins contain EGF-like Cys-rich segments (CRD1 and CRD2) connected by an intervening linker domain (L). The purpose of this study was to determine the functional activity of human MUC17 membrane-bound mucin. Methods Endogenous MUC17 was inhibited in LS174T colon cells by stable transfection of a small hairpin RNA targeting MUC17 (LSsi cells). The effect of recombinant MUC17-CRD1-L-CRD2 protein on migration, apoptosis, and experimental colitis was determined. Results Reduced MUC17 expression in LSsi cells was associated with visibly reduced cell aggregation, reduced cell–cell adherence, and reduced cell migration, but no change in tumorigenicity. LSsi cells also demonstrated a 3.7-fold increase in apoptosis rates compared with control cells following treatment with etoposide. Exposure of colonic cell lines to exogenous recombinant MUC17-CRD1-L-CRD2 protein significantly increased cell migration and inhibited apoptosis. As a marker of biologic activity, MUC17-CRD1-L-CRD2 proteins stimulate ERK phosphorylation in colonic cell lines; and inhibition of ERK phosphorylation reduced the anti-apoptosis and migratory effect of MUC17-CRD1-L-CRD2. Finally, mice treated with MUC17-CRD1-L-CRD2 protein given per rectum demonstrated accelerated healing in acetic acid and dextran sodium sulfate induced colitis in vivo . These data indicate that both native MUC17 and the exogenous recombinant cysteine-rich domain of MUC17 play a role in diverse cellular mechanisms related to cell restitution, and suggest a potential role for MUC17-CRD1-L-CRD2 recombinant protein in the treatment of mucosal inflammatory diseases.
Wade M Junker - One of the best experts on this subject based on the ideXlab platform.
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human intestinal MUC17 mucin augments intestinal cell restitution and enhances healing of experimental colitis
The International Journal of Biochemistry & Cell Biology, 2010Co-Authors: Wade M Junker, Satyanarayana Rachagani, Surinder K. Batra, Robert L Heinrikson, Laurie L Shekels, Samuel B HoAbstract:Abstract The membrane-bound mucins, MUC17 (human) and Muc3 (mouse), are highly expressed on the apical surface of intestinal epithelia and are thought to be cytoprotective. The extracellular regions of these mucins contain EGF-like Cys-rich segments (CRD1 and CRD2) connected by an intervening linker domain (L). The purpose of this study was to determine the functional activity of human MUC17 membrane-bound mucin. Methods Endogenous MUC17 was inhibited in LS174T colon cells by stable transfection of a small hairpin RNA targeting MUC17 (LSsi cells). The effect of recombinant MUC17-CRD1-L-CRD2 protein on migration, apoptosis, and experimental colitis was determined. Results Reduced MUC17 expression in LSsi cells was associated with visibly reduced cell aggregation, reduced cell–cell adherence, and reduced cell migration, but no change in tumorigenicity. LSsi cells also demonstrated a 3.7-fold increase in apoptosis rates compared with control cells following treatment with etoposide. Exposure of colonic cell lines to exogenous recombinant MUC17-CRD1-L-CRD2 protein significantly increased cell migration and inhibited apoptosis. As a marker of biologic activity, MUC17-CRD1-L-CRD2 proteins stimulate ERK phosphorylation in colonic cell lines; and inhibition of ERK phosphorylation reduced the anti-apoptosis and migratory effect of MUC17-CRD1-L-CRD2. Finally, mice treated with MUC17-CRD1-L-CRD2 protein given per rectum demonstrated accelerated healing in acetic acid and dextran sodium sulfate induced colitis in vivo . These data indicate that both native MUC17 and the exogenous recombinant cysteine-rich domain of MUC17 play a role in diverse cellular mechanisms related to cell restitution, and suggest a potential role for MUC17-CRD1-L-CRD2 recombinant protein in the treatment of mucosal inflammatory diseases.
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functional characterization of MUC17 in pancreatic adenocarcinoma cells
Cancer Research, 2008Co-Authors: Wade M Junker, Surinder K. BatraAbstract:1938 Mucin glycoproteins are implicated in various cancer types and are being actively studied due to their deregulated expression patterns, which can differentiate normal tissues from their malignant counterparts. Of particular interest is our recently characterized mucin 17 (MUC17), a membrane-anchored glycoprotein that is normally expressed in the gastrointestinal tract. We have reported that MUC17 is aberrantly expressed in pancreatic tumor cells and tumor cell lines with no expression detected in the normal pancreas or in benign pancreatitis tissues (Moniaux N., et al. 2006, 281, 23676-23685). Therefore, our working hypothesis is that MUC17 is implicated in the pathogenesis of pancreatic cancer. The MUC17 gene encodes a message of 14.4 Kb. Due to the large size of MUC17, a retroviral system was used to express a stable MUC17-specific RNAi that knocked down expression in the MUC17 expressing AsPC-1 pancreatic adenocarcinoma cell line. Both single colony clones and clonal populations of knock-down cells were assessed alongside parental AsPC-1 or AsPC-1 cells expressing a stable scrambled RNAi sequence. MUC17 knocked down cell lines displayed increased growth kinetics with reduced doubling time. Adhesion to cell culture surface was similar between knock-down and control populations; however, an increased motility was observed in the absence of MUC17 (motility and wound-healing assays). Knock-down and control population cell lines showed similar aggregation in hanging drop aggregation assays. No difference was observed in tests for clonogenic potential or in soft agar assays for tumorigenic potential. Xenotransplantation of the AsPC-1 cell line/model produces tumors with differentiation ranging from well to poorly differentiated adenocarcinomas. In the absence of MUC17, increased tumor weights were observed; however, no statistical difference between clonal populations of parental and knock-down (p=.1967) or scrambled and knock-down (p=.3772) cell lines was detected due to a large variance among tumor weights. In conclusion, our in vitro and in vivo results show that the absence of MUC17 in the AsPC-1 pancreatic model results in a pattern of increased tumorigenic potential. MUC17 expression in pancreatic cancer may therefore be an attempt to prevent tumorigenic growth or could be a surrogate consequence of altered signaling pathways in the cancerous state. The potential for MUC17 to mediate adhesion while conveying outside signals to the intracellular machinery is great. Microarray analysis and mechanistic study of scrambled versus knock-down populations will be performed. Additionally, a pancreas-specific mouse model, in which K-Ras is genetically inactivated and results in pancreatic cancer, is under development. The model will be used to assess the role of the MUC17 mouse homologue mMUC17 (work, in part, was supported by the NIH grants UO1 CA 111294 and T32 CA09476).
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regulation of human mucin MUC17 expression in pancreatic adenocarcinoma cells
Cancer Research, 2008Co-Authors: Wade M Junker, Surinder K. BatraAbstract:78 Pancreatic cancer is a devastating malignancy for which treatment and detection remain enigmatic. New diagnostic markers, therapeutics, and a better understanding of disease progression are urgently required to improve survival of patients. The mucin glycoproteins are a family of diverse molecules that have enabled us to detect cancers in relation to their normal tissue counterparts. One such mucin, mucin 17 (MUC17), is detected in pancreatic cancer tissues, which sharply contrasts the absence of MUC17 expression in the normal pancreas. We hypothesized that specific pathways, which are associated with expression of MUC17, control its aberrant expression and are activated in pancreatic cancer. To determine the significance of MUC17 expression in pancreatic cancer, it was necessary to define the underlying molecular mechanisms implicated in its aberrant expression. The pancreatic adenocarcinoma AsPC-1 cell line was used to investigate which signaling pathways contribute to MUC17 expression. Our data show that a 1,168 bp region proximal to the MUC17 coding sequence contains both promoter and enhancer activities. The MUC17 transcription initiator was identified and confirmed by primer extension analysis. Transcription initiates 54bp upstream of the ATG codon previously identified as the translation initiation site (Moniaux N., et al. 2006, 281, 23676-23685). Using databases, potential transcription factor binding sites (including those for: VDR/RXR heterodimers, NFκB, SMAD3, SMAD4, CDX-2, PDX-1, MZF-1, KLFs, GATA-1, AP-1, and growth factor responsiveness) were identified. Luciferase reporter assay results in AsPC-1 cells provide evidence that the cytokines, TNF-α and IL-6, and the growth factors, TGFβ-1, TGFβ-2, and EGF, are capable of activating transcription by increasing enhancer and/or basal promoter activities. Quantitative real-time PCR and western blotting demonstrate that an observed increase in MUC17 message results in increased production of MUC17 at the protein level, via activation by exogenous cytokines and growth factors and is dose and time dependent. Our results also provide evidence that combinations of growth factors (EGF + TGFβ-1) or growth factor and cytokine (TGFβ-2 + IL-6) up regulate MUC17 in an additive manner. Of particular interest is that when the cytokine TNF-α is combined with growth factors (+EGF, +TGFβ-1, or +TGFβ-2) a general decrease in MUC17 expression is observed (below that of TNF-α or growth factor treatment alone). This suggests that a counter mechanism exists for the down regulation of MUC17. MUC17 expression in the presence of growth factors or IL-6 may decrease if signals such as TNF-α are produced. Additional studies are underway to determine if expression of MUC17 is involved in the progression of disease or is lost as the result of developing inflammation associated with ductal pancreatic cancer (work, in part, was supported by the NIH grants UO1 CA 111294 and T32 CA09476).
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aberrant phenotypic expression of MUC17 is associated with aggressive behavior of colorectal adenocarcinomas
Cancer Research, 2008Co-Authors: Chandrakumar Shanmugam, Surinder K. Batra, Wade M Junker, Nirag Jhala, Sreelatha Meleth, William Grizzle, Upender ManneAbstract:987 Background: Mucins are the major secreted glycoprotein of gastrointestinal tract including the colon and the rectum. Aberrant expression of mucins has been known to play a role in colorectal carcinogenesis. Increased expression of MUC17, a recently identified membrane tethered mucin, was reported in pancreatic tumor tissues and in cancer cell lines of pancreas and colon. Nevertheless, the staining patterns of MUC17 and their clinical significance in colorectal adenocarcinomas (CRCs) have not been studied. Methods: One hundred and thirty six patients, who underwent surgical resection for CRC and had not received any pre- or -post surgery therapy, were selected for this study. Formalin-fixed paraffin embedded tissue specimens from these patients were evaluated for phenotypic expression of MUC17 using rabbit polyclonal antibody and horse-radish peroxidase detection method. The expression levels and patterns were correlated with different clinicopathologic features and patient outcomes. Results: In our study, MUC17 was localized to the cytoplasm, specifically in supra-nuclear position (punctate pattern), in all benign colonic epithelial tissues. In contrast, we observed two distinct patterns either punctate (60 of 136, 44%) or diffuse cytoplasmic (76 of 136, 56%) staining in tumor tissues. The cases in which the tumors exhibited diffuse cytoplasmic pattern were considered to be aberrant expressors of MUC17. The aberrant expression of MUC17 was significantly correlated with poor tumor differentiation (χ2, P=0.021) and with larger tumor size (χ2, P=0.011). Also, patients whose tumors demonstrated loss of punctate staining (diffuse cytoplasmic) patterns of MUC17 had a trend towards poor overall patient survival (logrank, P=0.072).Conclusion:These preliminary results suggest that the loss of punctate immunostaining pattern of MUC17 is associated with an aggressive behavior of colorectal adenocarcinomas and poor patient survival. This work is supported by funds from the National Institute of Health/National Cancer Institute (RO1-CA98932-01, 2U54-CA118948-03, U01CA111294, and the Early Detection Research Network, U24-CA086359).
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characterization of human mucin MUC17 complete coding sequence and organization
Journal of Biological Chemistry, 2006Co-Authors: Nicolas Moniaux, Wade M Junker, Ajay P Singh, Andria M Jones, Surinder K. BatraAbstract:Abstract With increasing interest on mucins as diagnostic and therapeutic targets in cancers and other diseases, it is becoming imperative to characterize novel mucins and investigate their biological significance. Here, we present the completed coding sequence and genomic organization of the previously published partial cDNA sequence of MUC17. Rapid amplification of cDNA ends with PCR, sequences from the Human Genome databases, and in vitro transcription/translational assays were used for these analyses. The MUC17 gene is located within a 39-kb DNA fragment between MUC12 and SERPINE1 on chromosome 7 in the region q22.1. The full-length coding sequence of MUC17 transcribes a 14.2-kb mRNA encompassing 13 exons. Alternate splicing generates two variants coding for a membrane-anchored and a secreted form. The canonical variable number of tandem repeats polymorphism of the central tandem repeat domain of the MUC genes is not significantly detected in the MUC17 gene. In addition, we show the overexpression of MUC17 by Western blot and immunohistochemical analyses in pancreatic tumor cell lines and tumor tissues compared with the normal pancreas. The expression of MUC17 is regulated by a 1,146-bp fragment upstream of MUC17 that contains VDR/RXR, GATA, NFκB, and Cdx-2 response elements.