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Cooney JM, Barnett MPG, Brewster D, Knoch B, McNabb WC, Laing WA, Roy NC. Proteomic Analysis of Colon Tissue from Interleukin-10 Gene-Deficient Mice Fed Polyunsaturated Fatty Acids with Comparison to Transcriptomic Analysis. J Proteome Res 2011; 11:1065-77. [DOI: 10.1021/pr200807p] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Janine M. Cooney
- Biological Chemistry & Bioactives, Food Innovation, The New Zealand Institute for Plant & Food Research Ltd, Ruakura Private Bag 3123, Waikato Mail Centre, Hamilton 3240, New Zealand
| | | | - Diane Brewster
- Biological Chemistry & Bioactives, Food Innovation, The New Zealand Institute for Plant & Food Research Ltd, Ruakura Private Bag 3123, Waikato Mail Centre, Hamilton 3240, New Zealand
| | | | | | - William A. Laing
- Biological Chemistry & Bioactives, Food Innovation, The New Zealand Institute for Plant & Food Research Ltd, Ruakura Private Bag 3123, Waikato Mail Centre, Hamilton 3240, New Zealand
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52
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Absence of keratin 8 confers a paradoxical microflora-dependent resistance to apoptosis in the colon. Proc Natl Acad Sci U S A 2011; 108:1445-50. [PMID: 21220329 DOI: 10.1073/pnas.1010833108] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Keratin 8 (K8) is a major intermediate filament protein present in enterocytes and serves an antiapoptotic function in hepatocytes. K8-null mice develop colonic hyperplasia and colitis that are reversed after antibiotic treatment. To investigate the pathways that underlie the mechanism of colonocyte hyperplasia and the normalization of the colonic phenotype in response to antibiotics, we performed genome-wide microarray analysis. Functional annotation of genes that are differentially regulated in K8(-/-) and K8(+/+) isolated colon crypts (colonocytes) identified apoptosis as a major altered pathway. Exposure of K8(-/-) colonocytes or colon organ ("organoid") cultures, but not K8(-/-) small intestine organoid cultures, to apoptotic stimuli showed, surprisingly, that they are resistant to apoptosis compared with their wild-type counterparts. This resistance is not related to inflammation per se because T-cell receptor α-null (TCR-α(-/-)) and wild-type colon cultures respond similarly upon induction of apoptosis. Following antibiotic treatment, K8(-/-) colonocytes and organ cultures become less resistant to apoptosis and respond similarly to the wild-type colonocytes. Antibiotics also normalize most differentially up-regulated genes, including survivin and β4-integrin. Treatment of K8(-/-) mice with anti-β4-integrin antibody up-regulated survivin, and induced phosphorylation of focal adhesion kinase with decreased activation of caspases. Therefore, unlike the proapoptotic effect of K8 mutation or absence in hepatocytes, lack of K8 confers resistance to colonocyte apoptosis in a microflora-dependent manner.
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53
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Khan AQ, Bury JP, Brown SR, Riley SA, Corfe BM. Keratin 8 expression in colon cancer associates with low faecal butyrate levels. BMC Gastroenterol 2011; 11:2. [PMID: 21219647 PMCID: PMC3027188 DOI: 10.1186/1471-230x-11-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Accepted: 01/10/2011] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Butyrate has been implicated in the mechanistic basis of the prevention of colorectal cancer by dietary fibre. Numerous in vitro studies have shown that butyrate regulates cell cycle and cell death. More recently we have shown that butyrate also regulates the integrity of the intermediate filament (IF) cytoskeleton in vitro. These and other data suggest a link between the role of diet and the implication of a central role for the keratin 8 (K8) as guardian of the colorectal epithelium. METHODS In this cross-sectional study possible links between butyrate levels, field effects and keratin expression in cancer were addressed directly by analysing how levels of expression of the IF protein K8 in tumours, in adjacent fields and at a distant landmark site may be affected by the level of butyrate in the colon microenvironment. An immunohistochemical scoring protocol for K8 was developed and applied to samples, findings were further tested by immunoblotting. RESULTS Levels of K8 in colorectal tumours are lower in subjects with higher levels of faecal butyrate. Immunoblotting supported this finding.Although there were no significant relationships with butyrate on the non-tumour tissues, there was a consistent trend in all measures of extent or intensity of staining towards a reduction in expression with elevated butyrate, consistent with the inverse association in tumours. CONCLUSIONS The data suggest that butyrate may associate with down-regulation of the expression of K8 in the cancerized colon. If further validated these findings may suggest the chemopreventive value of butyrate is limited to early stage carcinogenesis as low K8 expression is associated with a poor prognosis.
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Affiliation(s)
- Abdul Q Khan
- Department of Oncology, University of Sheffield, Medical School, Beech Hill Road, Sheffield, S10 2JF, UK
- Department of Gastroenterology, Northern General Hospital, Herries Road, Sheffield, S5 7AU, UK
| | - Jonathan P Bury
- Department of Oncology, University of Sheffield, Medical School, Beech Hill Road, Sheffield, S10 2JF, UK
| | - Steven R Brown
- Department of Gastroenterology, Northern General Hospital, Herries Road, Sheffield, S5 7AU, UK
| | - Stuart A Riley
- Department of Gastroenterology, Northern General Hospital, Herries Road, Sheffield, S5 7AU, UK
| | - Bernard M Corfe
- Department of Oncology, University of Sheffield, Medical School, Beech Hill Road, Sheffield, S10 2JF, UK
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54
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Ding Y, Lu B, Chen D, Meng L, Shen Y, Chen S. Proteomic analysis of colonic mucosa in a rat model of irritable bowel syndrome. Proteomics 2010; 10:2620-30. [PMID: 20461717 DOI: 10.1002/pmic.200900572] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Irritable bowel syndrome (IBS) is one of the most common functional disorders of the gastrointestinal tract. It is characterized by abdominal pain and changes in bowel habits. Various studies have investigated the pathophysiologic processes underlying IBS, but the mechanism remains poorly understood. In the present study, we established an IBS model and identified differentially expressed proteins in colon tissue of IBS rats compared with healthy controls by 2-D gel electrophoresis, MALDI-TOF-MS, and Western blot analysis. Our results showed that 13 of the 1396 protein spots on 2-D gel were differently expressed between the IBS and control groups. Ontological analysis of these proteins revealed primary roles in catalytic activity (protein disulfide-isomerase A3, glyoxalase I, cathepsin S, alpha-enolase), structural support (cytokeratin 8), antioxidant activity (peroxiredoxin-6), protein binding (transgelin, serpin peptidase inhibitor B5), and signal transduction (40S ribosomal protein SA). Protein disulfide-isomerase A3 and cytokeratin 8 overexpression in IBS were confirmed by Western blot. The findings indicate that multiple proteins are involved in IBS processes that influence intestinal tract immunity, inflammation, and nerve regulation. Our study provides useful candidate genes and proteins for further investigation.
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Affiliation(s)
- Ying Ding
- Department of Gastroenterology, First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, P R China
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55
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Abstract
Keratins are the intermediate filament (IF)-forming proteins of epithelial cells. Since their initial characterization almost 30 years ago, the total number of mammalian keratins has increased to 54, including 28 type I and 26 type II keratins. Keratins are obligate heteropolymers and, similarly to other IFs, they contain a dimeric central α-helical rod domain that is flanked by non-helical head and tail domains. The 10-nm keratin filaments participate in the formation of a proteinaceous structural framework within the cellular cytoplasm and, as such, serve an important role in epithelial cell protection from mechanical and non-mechanical stressors, a property extensively substantiated by the discovery of human keratin mutations predisposing to tissue-specific injury and by studies in keratin knockout and transgenic mice. More recently, keratins have also been recognized as regulators of other cellular properties and functions, including apico-basal polarization, motility, cell size, protein synthesis and membrane traffic and signaling. In cancer, keratins are extensively used as diagnostic tumor markers, as epithelial malignancies largely maintain the specific keratin patterns associated with their respective cells of origin, and, in many occasions, full-length or cleaved keratin expression (or lack there of) in tumors and/or peripheral blood carries prognostic significance for cancer patients. Quite intriguingly, several studies have provided evidence for active keratin involvement in cancer cell invasion and metastasis, as well as in treatment responsiveness, and have set the foundation for further exploration of the role of keratins as multifunctional regulators of epithelial tumorigenesis.
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Affiliation(s)
- V Karantza
- Department of Medicine, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Piscataway, NJ, USA.
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56
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Menon MB, Schwermann J, Singh AK, Franz-Wachtel M, Pabst O, Seidler U, Omary MB, Kotlyarov A, Gaestel M. p38 MAP kinase and MAPKAP kinases MK2/3 cooperatively phosphorylate epithelial keratins. J Biol Chem 2010; 285:33242-33251. [PMID: 20724476 DOI: 10.1074/jbc.m110.132357] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The MAPK-activated protein kinases (MAPKAP kinases) MK2 and MK3 are directly activated via p38 MAPK phosphorylation, stabilize p38 by complex formation, and contribute to the stress response. The list of substrates of MK2/3 is increasing steadily. We applied a phosphoproteomics approach to compare protein phosphorylation in MK2/3-deficient cells rescued or not by ectopic expression of MK2. In addition to differences in phosphorylation of the known substrates of MK2, HSPB1 and Bag-2, we identified strong differences in phosphorylation of keratin 8 (K8). The phosphorylation of K8-Ser(73) is catalyzed directly by p38, which in turn shows MK2-dependent expression. Notably, analysis of small molecule p38 inhibitors on K8-Ser(73) phosphorylation also demonstrated reduced phosphorylations of keratins K18-Ser(52) and K20-Ser(13) but not of K8-Ser(431) or K18-Ser(33). Interestingly, K18-Ser(52) and K20-Ser(13) are not directly phosphorylated by p38 in vitro, but by MK2. Furthermore, anisomycin-stimulated phosphorylations of K20-Ser(13) and K18-Ser(52) are inhibited by small molecule inhibitors of both p38 and MK2. MK2 knockdown in HT29 cells leads to reduced K20-Ser(13) phosphorylation, which further supports the notion that MK2 is responsible for K20 phosphorylation in vivo. Physiologic relevance of these findings was confirmed by differences of K20-Ser(13) phosphorylation between the ileum of wild-type and MK2/3-deficient mice and by demonstrating p38- and MK2-dependent mucin secretion of HT29 cells. Therefore, MK2 and p38 MAPK function in concert to phosphorylate K8, K18, and K20 in intestinal epithelia.
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Affiliation(s)
- Manoj B Menon
- From the Institute of Biochemistry, Hannover 30625, Germany
| | | | - Anurag Kumar Singh
- Department of Gastroenterology, Hepatology, and Endocrinology, Hannover 30625, Germany
| | - Mirita Franz-Wachtel
- Proteome Center Tübingen, Interfaculty Institute for Cell Biology, University of Tübingen, Tübingen 72076, Germany
| | - Oliver Pabst
- Institute of Immunology, Medical School Hannover, Hannover 30625, Germany
| | - Ursula Seidler
- Department of Gastroenterology, Hepatology, and Endocrinology, Hannover 30625, Germany
| | - M Bishr Omary
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan 48109
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57
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Abstract
The human intestine is colonized by an estimated 100 trillion bacteria. Some of these bacteria are essential for normal physiology, whereas others have been implicated in the pathogenesis of multiple inflammatory diseases including IBD and asthma. This review examines the influence of signals from intestinal bacteria on the homeostasis of the mammalian immune system in the context of health and disease. We review the bacterial composition of the mammalian intestine, known bacterial-derived immunoregulatory molecules, and the mammalian innate immune receptors that recognize them. We discuss the influence of bacterial-derived signals on immune cell function and the mechanisms by which these signals modulate the development and progression of inflammatory disease. We conclude with an examination of successes and future challenges in using bacterial communities or their products in the prevention or treatment of human disease.
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Affiliation(s)
- David A Hill
- University of Pennsylvania School of Veterinary Medicine, Department of Pathobiology, Philadelphia, 19104-4539, USA
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58
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Abstract
Epithelia form barriers that are essential to life. This is particularly true in the intestine, where the epithelial barrier supports nutrient and water transport while preventing microbial contamination of the interstitial tissues. Along with plasma membranes, the intercellular tight junction is the primary cellular determinant of epithelial barrier function. Disruption of tight junction structure, as a result of specific protein mutations or aberrant regulatory signals, can be both a cause and an effect of disease. Recent advances have provided new insights into the extracellular signals and intracellular mediators of tight junction regulation in disease states as well as into the interactions of intestinal barrier function with mucosal immune cells and luminal microbiota. In this review, we discuss the critical roles of the tight junction in health and explore the contributions of barrier dysfunction to disease pathogenesis.
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Affiliation(s)
- Amanda M Marchiando
- Department of Pathology, Graduate Program in Molecular Pathogenesis and Molecular Medicine, The University of Chicago, Chicago, Illinois, 60637, USA.
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59
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Affiliation(s)
- Clara Abraham
- Department of Internal Medicine, Section of Digestive Diseases, Yale University School of Medicine, New Haven, CT 06520, USA
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60
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Rosenstiel P, Sina C, Franke A, Schreiber S. Towards a molecular risk map--recent advances on the etiology of inflammatory bowel disease. Semin Immunol 2009; 21:334-45. [PMID: 19926490 DOI: 10.1016/j.smim.2009.10.001] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2009] [Accepted: 10/14/2009] [Indexed: 12/11/2022]
Abstract
Recent advances have enabled a comprehensive understanding of the genetic architecture of inflammatory bowel disease (IBD) with over 30 identified and replicated disease loci. The pathophysiological consequences of disease gene variants in Crohn disease and ulcerative colitis, the two main subentities of IBD, so far are only understood on the single disease gene level, yet complex network analyses linking the individual risk factors into a molecular risk map are still missing. In this review, we will focus on recent pathways and cellular functions that emerged from the genetic studies (e.g. innate immunity, autophagy) and delineate the existence of shared (e.g. IL23R, IL12B) and unique (e.g. NOD2 for CD) risk factors for the disease subtypes. Ultimately, the defined molecular profiles may identify individuals at risk early in life and may serve as a guidance to administer personalized interventions for causative therapies and/or early targeted prevention strategies. Due to this comparatively advanced level of molecular understanding in the field, IBD may represent precedent also for future developments of individualized genetic medicine in other polygenic disorders in general.
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Affiliation(s)
- Philip Rosenstiel
- Institute for Clinical Molecular Biology, Christian-Albrechts University of Kiel, Schittenhelmstr. 12, D-24105 Kiel, Germany.
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61
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Luo YX, Cui J, Wang L, Chen DK, Peng JS, Lan P, Huang MJ, Huang YH, Cai SR, Hu KH, Li MT, Wang JP. Identification of cancer-associated proteins by proteomics and downregulation of β-tropomyosin expression in colorectal adenoma and cancer. Proteomics Clin Appl 2009; 3:1397-406. [PMID: 21136959 DOI: 10.1002/prca.200900070] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2009] [Revised: 08/09/2009] [Accepted: 08/24/2009] [Indexed: 12/12/2022]
Abstract
Elucidating the molecular mechanism underlying the development of adenoma, the major precursor lesion of colorectal cancer (CRC), would provide a basis for early detection, prevention as well as treatment of CRC. Using the highly sensitive 2-D DIGE method coupled with MS, we identified 24 differentially expressed proteins in adenoma tissues compared with matched normal colonic mucosa and CRC tissues. Fifteen proteins were downregulated and three proteins were upregulated in adenoma tissues when compared with individual-matched normal colonic mucosa. Five proteins were downregulated, while one protein was upregulated in adenoma tissues when compared with matched CRC tissues. A protein, β-tropomyosin (TM-β), recently suggested to be a biomarker of esophageal squamous carcinoma, was downregulated in both adenoma and CRC tissues. Additionally, the reduction in the level of TM-β in adenoma and CRC tissues was further validated by Western blotting (p<0.05) and RT-PCR (p<0.001). Our findings suggest that downregulation of TM-β is involved in the early development of CRC and that differentially expressed proteins might serve as potential biomarkers for detection of CRC.
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Affiliation(s)
- Yan-Xin Luo
- Department of Colorectal Surgery, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, P. R. China; Gastrointestinal Institute, Sun Yat-Sen University, Guangzhou, P. R. China
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62
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Zhong B, Strnad P, Selmi C, Invernizzi P, Tao GZ, Caleffi A, Chen M, Bianchi I, Podda M, Pietrangelo A, Gershwin ME, Omary MB. Keratin variants are overrepresented in primary biliary cirrhosis and associate with disease severity. Hepatology 2009; 50:546-54. [PMID: 19585610 PMCID: PMC2756069 DOI: 10.1002/hep.23041] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
UNLABELLED Keratins (K) 8 and 18 variants predispose carriers to the development of end-stage liver disease and patients with chronic hepatitis C to disease progression. Hepatocytes express K8/K18, whereas biliary epithelia express K8/K18/K19. K8-null mice, which are predisposed to liver injury, spontaneously develop anti-mitochondrial antibodies (AMA) and have altered hepatocyte mitochondrial size and function. There is no known association of K19 with human disease and no known association of K8/K18/K19 with human autoimmune liver disease. We tested the hypothesis that K8/K18/K19 variants associate with primary biliary cirrhosis (PBC), an autoimmune cholestatic liver disease characterized by the presence of serum AMA. In doing so, we analyzed the entire exonic regions of K8/K18/K19 in 201 Italian patients and 200 control blood bank donors. Five disease-associated keratin heterozygous variants were identified in patients versus controls (K8 G62C/R341H/V380I, K18 R411H, and K19 G17S). Four variants were novel and included K19 G17S/V229M/N184N and K18 R411H. Overall, heterozygous disease-associated keratin variants were found in 17 of 201 (8.5%) PBC patients and 4 of 200 (2%) blood bank donors (P < 0.004, odds ratio = 4.53, 95% confidence interval = 1.5-13.7). Of the K19 variants, K19 G17S was found in three patients but not in controls and all K8 R341H (eight patients and three controls) associated with concurrent presence of the previously described intronic K8 IVS7+10delC deletion. Notably, keratin variants associated with disease severity (12.4% variants in Ludwig stage III/IV versus 4.2% in stages I/II; P < 0.04, odds ratio = 3.25, 95% confidence interval = 1.02-10.40), but not with the presence of AMA. CONCLUSION K8/K18/K19 variants are overrepresented in Italian PBC patients and associate with liver disease progression. Therefore, we hypothesize that K8/K18/K19 variants may serve as genetic modifiers in PBC.
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Affiliation(s)
| | | | - Carlo Selmi
- Division of Internal Medicine and Hepatobiliary Immunopathology Unit, Rozzano, Italy; University of Milan, Rozzano, Italy
| | - Pietro Invernizzi
- Division of Internal Medicine and Hepatobiliary Immunopathology Unit, Rozzano, Italy
| | - Guo-Zhong Tao
- Palo Alto VA Medical Center and Stanford University School of Medicine, Palo Alto, CA 94304 USA
| | - Angela Caleffi
- Center for Hemochromatosis, Department of Internal Medicine, University of Modena and Reggio Emilia, Modena, Italy
| | - Minhu Chen
- Division of Gastroenterology, First Affiliated Hospital of Sun Yat-sen University, Guangzhou, PR China
| | - Ilaria Bianchi
- Division of Internal Medicine and Hepatobiliary Immunopathology Unit, Rozzano, Italy; University of Milan, Rozzano, Italy
| | - Mauro Podda
- Division of Internal Medicine and Hepatobiliary Immunopathology Unit, Rozzano, Italy; University of Milan, Rozzano, Italy
| | - Antonello Pietrangelo
- Center for Hemochromatosis, Department of Internal Medicine, University of Modena and Reggio Emilia, Modena, Italy
| | - M. Eric Gershwin
- Division of Rheumatology, Allergy, and Clinical Immunology, University of California Davis, Davis, CA, USA
| | - M. Bishr Omary
- Address correspondence to: Bishr Omary, University of Michigan, School of Medicine, Department of Molecular & Integrative Physiology, 7744 Medical Science II, 1301 E. Catherine Street, Ann Arbor, MI 48109, (734) 647-2107 Phone; (734) 936-8813 Fax;
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63
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Omary MB, Ku NO, Strnad P, Hanada S. Toward unraveling the complexity of simple epithelial keratins in human disease. J Clin Invest 2009; 119:1794-805. [PMID: 19587454 DOI: 10.1172/jci37762] [Citation(s) in RCA: 212] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Simple epithelial keratins (SEKs) are found primarily in single-layered simple epithelia and include keratin 7 (K7), K8, K18-K20, and K23. Genetically engineered mice that lack SEKs or overexpress mutant SEKs have helped illuminate several keratin functions and served as important disease models. Insight into the contribution of SEKs to human disease has indicated that K8 and K18 are the major constituents of Mallory-Denk bodies, hepatic inclusions associated with several liver diseases, and are essential for inclusion formation. Furthermore, mutations in the genes encoding K8, K18, and K19 predispose individuals to a variety of liver diseases. Hence, as we discuss here, the SEK cytoskeleton is involved in the orchestration of several important cellular functions and contributes to the pathogenesis of human liver disease.
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Affiliation(s)
- M Bishr Omary
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
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64
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Abstract
Aseptic liver abscesses preceding the diagnosis of Crohn's disease are extremely rare. We report a patient with multiple liver abscesses that yielded negative microbiologic investigation and failed to develop full remission under antibiotic therapy. Diagnosis of Crohn's disease of small and large bowel was later established and she was started on sulfasalazine and azathioprine with total regression of the hepatic abscesses. This case illustrates the rare possibility of aseptic liver abscesses as an initial manifestation of Crohn's disease, which could be interpreted in the light of recent data on aberrant homing of gut T memory/effector lymphocytes in the liver.
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65
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Kang SS, Bloom SM, Norian LA, Geske MJ, Flavell RA, Stappenbeck TS, Allen PM. An antibiotic-responsive mouse model of fulminant ulcerative colitis. PLoS Med 2008; 5:e41. [PMID: 18318596 PMCID: PMC2270287 DOI: 10.1371/journal.pmed.0050041] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2007] [Accepted: 12/21/2007] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND The constellation of human inflammatory bowel disease (IBD) includes ulcerative colitis and Crohn's disease, which both display a wide spectrum in the severity of pathology. One theory is that multiple genetic hits to the host immune system may contribute to the susceptibility and severity of IBD. However, experimental proof of this concept is still lacking. Several genetic mouse models that each recapitulate some aspects of human IBD have utilized a single gene defect to induce colitis. However, none have produced pathology clearly distinguishable as either ulcerative colitis or Crohn's disease, in part because none of them reproduce the most severe forms of disease that are observed in human patients. This lack of severe IBD models has posed a challenge for research into pathogenic mechanisms and development of new treatments. We hypothesized that multiple genetic hits to the regulatory machinery that normally inhibits immune activation in the intestine would generate more severe, reproducible pathology that would mimic either ulcerative colitis or Crohn's disease. METHODS AND FINDINGS We generated a novel mouse line (dnKO) that possessed defects in both TGFbetaRII and IL-10R2 signaling. These mice rapidly and reproducibly developed a disease resembling fulminant human ulcerative colitis that was quite distinct from the much longer and more variable course of pathology observed previously in mice possessing only single defects. Pathogenesis was driven by uncontrolled production of proinflammatory cytokines resulting in large part from T cell activation. The disease process could be significantly ameliorated by administration of antibodies against IFNgamma and TNFalpha and was completely inhibited by a combination of broad-spectrum antibiotics. CONCLUSIONS Here, we develop to our knowledge the first mouse model of fulminant ulcerative colitis by combining multiple genetic hits in immune regulation and demonstrate that the resulting disease is sensitive to both anticytokine therapy and broad-spectrum antibiotics. These findings indicated the IL-10 and TGFbeta pathways synergize to inhibit microbially induced production of proinflammatory cytokines, including IFNgamma and TNFalpha, which are known to play a role in the pathogenesis of human ulcerative colitis. Our findings also provide evidence that broad-spectrum antibiotics may have an application in the treatment of patients with ulcerative colitis. This model system will be useful in the future to explore the microbial factors that induce immune activation and characterize how these interactions produce disease.
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Affiliation(s)
- Silvia S Kang
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, United States of America
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66
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Kern JS, Herz C, Haan E, Moore D, Nottelmann S, von Lilien T, Greiner P, Schmitt-Graeff A, Opitz OG, Bruckner-Tuderman L, Has C. Chronic colitis due to an epithelial barrier defect: the role of kindlin-1 isoforms. J Pathol 2008; 213:462-70. [PMID: 17955455 DOI: 10.1002/path.2253] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Kindlin-1 is an epithelium-specific phosphoprotein and focal adhesion adaptor component. Mutations in the corresponding gene (KIND1) cause Kindler syndrome (KS), which is manifested by skin blistering, poikiloderma, photosensitivity and carcinogenesis. Some patients also exhibit gastrointestinal symptoms, but it has remained unclear whether these represent a feature of Kindler syndrome or a coincidence. We examined kindlin-1 in human gastrointestinal epithelia and showed that it is involved in the aetiopathology of Kindler syndrome-associated colitis. Kindlin-1 expression was assessed by indirect immunofluorescence, western blot and RT-PCR. Kindlin-1 is expressed in oral mucosa, colon and rectum. Both the full-length 74 kDa kindlin-1 protein and a 43 kDa isoform were detected in CaCo2 cells, the latter resulting from alternative splicing. In the first months of life, patients (homozygous for null mutations) had severe intestinal involvement with haemorrhagic diarrhoea and showed morphological features of severe ulcerative colitis. Later in childhood, histopathology demonstrated focal detachment of the epithelium in all segments of the colon, chronic inflammation and mucosal atrophy. These findings define an intestinal phenotype for Kindler syndrome as a consequence of a primary epithelial barrier defect. The different clinical intestinal manifestations in Kindler syndrome patients may be explained by partial functional compensation of kindlin-1 deficiency by the intestinal isoform or by the presence of truncated mutant kindlin-1.
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Affiliation(s)
- J S Kern
- Department of Dermatology, University Medical Center, Freiburg, Germany
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67
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Nguyen DD, Maillard MH, Cotta-de-Almeida V, Mizoguchi E, Klein C, Fuss I, Nagler C, Mizoguchi A, Bhan AK, Snapper SB. Lymphocyte-dependent and Th2 cytokine-associated colitis in mice deficient in Wiskott-Aldrich syndrome protein. Gastroenterology 2007; 133:1188-97. [PMID: 17764675 PMCID: PMC2048975 DOI: 10.1053/j.gastro.2007.07.010] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2006] [Accepted: 06/28/2007] [Indexed: 12/16/2022]
Abstract
BACKGROUND & AIMS Controversy exists as to whether patients with inflammatory bowel disease have an underlying immunodeficiency. We have focused on a murine model of the Wiskott-Aldrich syndrome, an immunodeficiency in which autoimmunity can manifest in the form of an inflammatory bowel disease-like illness. Wiskott-Aldrich syndrome protein (WASP) deficiency in mice results in similar clinical features. Herein, we characterized the colitis in WASP-deficient mice. METHODS WASP-deficient mice were followed clinically and histologically. Immunologic studies were performed to determine the pathogenic cell population(s), the predominant cytokine expression pattern, and the role of cytokine(s) in colitis pathogenesis. RESULTS All WASP-deficient mice develop colitis by 6 months of age. Lymphocytes are required for disease induction, and CD4(+) T cells from WASP-deficient mice are sufficient to induce disease in lymphocyte-deficient hosts. Lamina propria preparations from WASP-deficient mice demonstrated elevations in interferon-gamma, interleukin (IL)-4, and IL-13 levels but decreased IL-6 and no difference in IL-17 expression in comparison with wild-type controls. Treatment with neutralizing antibody to IL-4, but not to interferon-gamma, abrogated colitis development. However, mice deficient in both WASP and IL-4 showed no difference in histologic colitis scores at 24 weeks of age compared with WASP-deficient mice. CONCLUSIONS These results demonstrate a critical role for lymphocytes and a relative T helper 2 cytokine predominance in the colitis associated with WASP-deficient mice. This is the only model of colitis with elevated T helper 2 cytokines and aberrant natural regulatory T cell function and is unique in having a human disease counterpart with similar defects.
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Affiliation(s)
- Deanna D Nguyen
- Gastrointestinal Unit, Massachusetts General Hospital, Boston, Massachusetts 02114, USA
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68
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Tao GZ, Strnad P, Zhou Q, Kamal A, Zhang L, Madani ND, Kugathasan S, Brant SR, Cho JH, Omary MB, Duerr RH. Analysis of keratin polypeptides 8 and 19 variants in inflammatory bowel disease. Clin Gastroenterol Hepatol 2007; 5:857-64. [PMID: 17509943 DOI: 10.1016/j.cgh.2007.02.017] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND/AIMS Keratin-8 (KRT8)-null mice develop spontaneous colitis and predisposition to liver injury. Human studies show that some KRT8 variants predispose to end-stage liver disease and progression and suggest that such variants might associate with UC or CD. We asked whether mutations in KRT8 or KRT19, the major intestinal keratins, are associated with UC/CD. METHODS Exonic regions of the KRT8/KRT19 genes were polymerase chain reaction-amplified using genomic DNA from 2 independent groups. Group I included 91 unrelated patients with CD, 93 unrelated patients with UC, and 70 unrelated/unaffected volunteers. KRT8 variants were also tested with pyrosequencing in Group II that included 682 independent nuclear families with both parents and at least 1 CD/UC-affected offspring and 273 unaffected controls. Both cohorts were enriched for familial IBD. RESULTS In Group I, KRT19 variants were identified in CD/UC patients within the promoter and exons 1+2, with similar mutation frequencies in the control/CD/UC groups. In contrast, 16 of 184 CD+UC patients harbored KRT8 heterozygous variants involving Gly62-to-Cys and Arg341-to-His and a novel Arg341-to-Cys, which were noted in 4 volunteers (Arg341-to-His) and correlated with extensive UC (P = .005). One family with unaffected parents had 3 pediatric-affected siblings with severe disease, 2 of whom are compound heterozygous (Gly62-to-Cys/Arg341-to-His). However, there was no significant departure from random transmission of the 3 alleles in Group II IBD families. CONCLUSIONS KRT8 and KRT19 variants are not overtransmitted or associated with familial IBD, although a potential role in sporadic IBD cannot be excluded. A novel but rare keratin-8 Arg341-to-Cys is identified in IBD patients.
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Affiliation(s)
- Guo-Zhong Tao
- Department of Medicine, Palo Alto Veterans Affairs Medical Center and Stanford University Digestive Disease Center, Palo Alto, California 94304, USA
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Oshima RG. Intermediate filaments: a historical perspective. Exp Cell Res 2007; 313:1981-94. [PMID: 17493611 PMCID: PMC1950476 DOI: 10.1016/j.yexcr.2007.04.007] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2007] [Revised: 04/03/2007] [Accepted: 04/05/2007] [Indexed: 01/08/2023]
Abstract
Intracellular protein filaments intermediate in size between actin microfilaments and microtubules are composed of a surprising variety of tissue specific proteins commonly interconnected with other filamentous systems for mechanical stability and decorated by a variety of proteins that provide specialized functions. The sequence conservation of the coiled-coil, alpha-helical structure responsible for polymerization into individual 10 nm filaments defines the classification of intermediate filament proteins into a large gene family. Individual filaments further assemble into bundles and branched cytoskeletons visible in the light microscope. However, it is the diversity of the variable terminal domains that likely contributes most to different functions. The search for the functions of intermediate filament proteins has led to discoveries of roles in diseases of the skin, heart, muscle, liver, brain, adipose tissues and even premature aging. The diversity of uses of intermediate filaments as structural elements and scaffolds for organizing the distribution of decorating molecules contrasts with other cytoskeletal elements. This review is an attempt to provide some recollection of how such a diverse field emerged and changed over about 30 years.
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Affiliation(s)
- Robert G Oshima
- Oncodevelopmental Biology Program, Cancer Research Center, The Burnham Institute for Medical Research, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA.
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Wang L, Srinivasan S, Theiss AL, Merlin D, Sitaraman SV. Interleukin-6 induces keratin expression in intestinal epithelial cells: potential role of keratin-8 in interleukin-6-induced barrier function alterations. J Biol Chem 2007; 282:8219-27. [PMID: 17213200 DOI: 10.1074/jbc.m604068200] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Keratin 8 (K8) and keratin-18 (K18) are the major intermediate filament proteins in the intestinal epithelia. The regulation and function of keratin in the intestinal epithelia is largely unknown. In this study we addressed the role and regulation of K8 and K18 expression by interleukin 6 (IL-6). Caco2-BBE cell line and IL-6 null mice were used to study the effect of IL-6 on keratin expression. Keratin expression was studied by Northern blot, Western blot, and confocal microscopy. Paracellular permeability was assessed by apical-to-basal transport of a fluorescein isothiocyanate dextran probe (FD-4). K8 was silenced using the small interfering RNA approach. IL-6 significantly up-regulated mRNA and protein levels of K8 and K18. Confocal microscopy showed a reticular pattern of intracellular keratin localized to the subapical region after IL-6 treatment. IL-6 also induced serine phosphorylation of K8. IL-6 decreased paracellular flux of FD-4 compared with vehicle-treated monolayers. K8 silencing abolished the decrease in paracellular permeability induced by IL-6. Administration of dextran sodium sulfate (DSS) significantly increased intestinal permeability in IL-6-/- mice compared with wild type mice given DSS. Collectively, our data demonstrate that IL-6 regulates the colonic expression of K8 and K18, and K8/K18 mediates barrier protection by IL-6 under conditions where intestinal barrier is compromised. Thus, our data uncover a novel function of these abundant cytoskeletal proteins, which may have implications in intestinal disorders such as inflammatory bowel disease wherein barrier dysfunction underlies the inflammatory response.
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Affiliation(s)
- Lixin Wang
- Division of Digestive Diseases, Department of Medicine, Emory University, Atlanta, Georgia 30322, USA
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Abstract
Our relationship with the colonic bacterial flora has long been viewed as benign, but recent studies suggest that this symbiosis has risks as well as benefits. This relationship requires that the host not only provide a supportive environment for the symbiotic bacteria, but also actively maintain intact mechanisms for properly managing the physiologic stresses that are closely associated with the symbiont’s essential survival functions. Failure to do so breaches the host-symbiont contract, and can result in serious effects on the health of the host. Recent investigations that employ several knockout mouse models reveal the consequences of genetic deficiency in the host regarding these mechanisms, and the latent, pro-inflammatory, tumorigenic nature of normal bacterial flora. Further study of the interactions between normal bacterial flora and hosts could shed light on the etiologies and pathogenesis of inflammatory diseases and related cancers, with implications for human health.
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Polley ACJ, Mulholland F, Pin C, Williams EA, Bradburn DM, Mills SJ, Mathers JC, Johnson IT. Proteomic analysis reveals field-wide changes in protein expression in the morphologically normal mucosa of patients with colorectal neoplasia. Cancer Res 2006; 66:6553-62. [PMID: 16818627 DOI: 10.1158/0008-5472.can-06-0534] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Models for the pathogenesis of colorectal cancer tend to focus on the localized lesion, with less attention paid to changes in normal-appearing mucosa. Here we used two-dimensional gel electrophoresis and mass spectrometry to define patterns of protein expression in morphologically normal colonic mucosa from 13 healthy subjects, 9 patients with adenomatous polyps, and 9 with cancer. Tumor samples were also compared with the normal mucosa. Systematic gel comparisons identified a total of 839 spots that differed significantly between one or more groups (P < 0.05). Principle component analysis indicated that the first three components accounted for approximately 37% of the total variation and provided clear evidence that flat mucosa from healthy subjects differed significantly from that of patients with polyps or cancer. Sixty-one proteins differed significantly between mucosa from healthy subjects and all other tissue types, and 206 differed significantly between healthy mucosa and polyp mucosa. Several of the proteins showing significant underexpression in tumor tissue were cytokeratins and other cytoskeletal components. In contrast, cytokeratins, including several isoforms of cytokeratin 8, were overexpressed in apparently normal mucosa from polyp and cancer patients compared with mucosa from healthy subjects. These findings indicate that protein expression in the apparently normal colonic mucosal field is modified in individuals with neoplastic lesions at sites distant from the lesion. Recognition and further characterization of this field effect at the molecular level may provide protein biomarkers of susceptibility to colorectal cancer and facilitate development of hypotheses for the role of diet and other environmental factors in its causation.
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Toivola DM, Tao GZ, Habtezion A, Liao J, Omary MB. Cellular integrity plus: organelle-related and protein-targeting functions of intermediate filaments. Trends Cell Biol 2005; 15:608-17. [PMID: 16202602 DOI: 10.1016/j.tcb.2005.09.004] [Citation(s) in RCA: 186] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2005] [Revised: 08/12/2005] [Accepted: 09/20/2005] [Indexed: 02/06/2023]
Abstract
Intermediate filament proteins (IFs) maintain cell and tissue integrity, based on evidence of their polymerization and mechanical properties, abundance and disease-associated phenotypes. This 'traditional' function is now augmented by organelle-related and protein-targeting roles. Mitochondrial location and function depend on intact IFs, as demonstrated for desmin, keratins and neurofilaments. Golgi positioning is regulated by several IFs, and endosomal/lysosomal protein distribution by vimentin. IFs dramatically affect nuclear function and shape and play a role in subcellular and membrane targeting of proteins. These functions have been noted in tissues but in some cases only in cell culture. The IF-related organelle-specific and protein-targeting roles, which are likely interrelated, provide functions beyond cell scaffolding and integrity and contribute to the cytoprotective and tissue-specific functions of IF proteins.
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Affiliation(s)
- Diana M Toivola
- Palo Alto VA Medical Center, 3801 Miranda Avenue, Palo Alto, CA 94304, USA
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