| 1. |
- Bonfiglio, F., et al.
(författare)
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Female-Specific Association Between Variants on Chromosome 9 and Self-Reported Diagnosis of Irritable Bowel Syndrome
- 2018
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Ingår i: Gastroenterology. - : Elsevier BV. - 0016-5085 .- 1528-0012. ; 155:1, s. 168-179
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND & AIMS: Genetic factors are believed to affect risk for irritable bowel syndrome (IBS), but there have been no sufficiently powered and adequately sized studies. To identify DNA variants associated with IBS risk, we performed a genome-wide association study (GWAS) of the large UK Biobank population-based cohort, which includes genotype and health data from 500,000 participants. METHODS: We studied 7,287,191 high-quality single nucleotide polymorphisms in individuals who self-reported a doctor's diagnosis of IBS (cases; n = 9576) compared to the remainder of the cohort (controls; n = 336,499) (mean age of study subjects, 40-69 years). Genome-wide significant findings were further investigated in 2045 patients with IBS from tertiary centers and 7955 population controls from Europe and the United States, and a small general population sample from Sweden (n = 249). Functional annotation of GWAS results was carried out by integrating data from multiple biorepositories to obtain biological insights from the observed associations. RESULTS: We identified a genome-wide significant association on chromosome 9q31.2 (single nucleotide polymorphism rs10512344; P = 3.57 x 10(-8)) in a region previously linked to age at menarche, and 13 additional loci of suggestive significance (P < 5.0 x 10(-6)). Sex-stratified analyses revealed that the variants at 9q31.2 affect risk of IBS in women only (P = 4.29 x 10(-10) in UK Biobank) and also associate with constipation-predominant IBS in women (P = .015 in the tertiary cohort) and harder stools in women (P = .0012 in the population-based sample). Functional annotation of the 9q31.2 locus identified 8 candidate genes, including the elongator complex protein 1 gene (ELP1 or IKB-KAP), which is mutated in patients with familial dysautonomia. CONCLUSIONS: In a sufficiently powered GWAS of IBS, we associated variants at the locus 9q31.2 with risk of IBS in women. This observation may provide additional rationale for investigating the role of sex hormones and autonomic dysfunction in IBS.
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| 2. |
- Awla, Darbaz, et al.
(författare)
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NFATc3 Regulates Trypsinogen Activation, Neutrophil Recruitment, and Tissue Damage in Acute Pancreatitis in Mice.
- 2012
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Ingår i: Gastroenterology. - : Elsevier BV. - 1528-0012 .- 0016-5085. ; 143:5, s. 1352-1352
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND & AIMS: The signaling mechanisms that regulate trypsinogen activation and inflammation in acute pancreatitis (AP) are unclear. We explored the involvement of the calcium- and calcineurin-dependent transcription factor nuclear factor of activated T-cells (NFAT) in development of AP in mice. METHODS: We measured levels of myeloperoxidase and macrophage inflammatory protein-2 (CXCL2), trypsinogen activation, and tissue damage in the pancreas 24 h after induction of AP by retrograde infusion of taurocholate into the pancreatic ducts of wild-type, NFAT luciferase reporter (NFAT-luc), and NFATc3-deficient mice. We isolated acinar cells and measured NFAT nuclear accumulation, trypsin activity, and expression of NFAT-regulated genes. RESULTS: Infusion of taurocholate increased the transcriptional activity of NFAT in the pancreas, aorta, lung, and spleen of NFAT-luc mice. Inhibition of NFAT with A-285222 blocked taurocholate-induced activation of NFAT in all organs. A-285222 also reduced taurocholate-induced increases in levels of amylase, myeloperoxidase and CXCL2; activation of trypsinogen; necrosis of acinar cells; edema; leukocyte infiltration; and hemorrhage in the pancreas. NFATc3-deficient mice were protected from these effects of taurocholate. Similar results were obtained using an L-arginine-induced model of AP. Reverse transcriptase PCR and confocal immunofluorescence analyses showed that NFATc3 is expressed by acinar cells. NFATc3 expression was activated by stimuli that increase intracellular calcium; activation was prevented by the calcineurin blocker cyclosporine A or A-285222. Activation of trypsinogen by secretagogues in acinar cells was prevented by pharmacologic inhibition of NFAT signaling or lack of NFATc3. A-285222 also reduced expression of inflammatory cytokines such as CXCL2 in acinar cells. CONCLUSIONS: NFATc3 regulates trypsinogen activation, inflammation, and pancreatic tissue damage during development of AP in mice, and might be a therapeutic target.
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| 3. |
- Beyder, Arthur, et al.
(författare)
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Loss-of-Function of the Voltage-Gated Sodium Channel Na(V)1.5 (Channelopathies) in Patients With Irritable Bowel Syndrome
- 2014
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Ingår i: Gastroenterology. - : Elsevier BV. - 0016-5085 .- 1528-0012. ; 146:7, s. 1659-1668
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND & AIMS: SCN5A encodes the a-subunit of the voltage-gated sodium channel Na(V)1.5. Many patients with cardiac arrhythmias caused by mutations in SCN5A also have symptoms of irritable bowel syndrome (IBS). We investigated whether patients with IBS have SCN5A variants that affect the function of Na(V)1.5. METHODS: We performed genotype analysis of SCN5A in 584 persons with IBS and 1380 without IBS (controls). Mutant forms of SCN5A were expressed in human embryonic kidney-293 cells, and functions were assessed by voltage clamp analysis. A genome-wide association study was analyzed for an association signal for the SCN5A gene, and replicated in 1745 patients in 4 independent cohorts of IBS patients and controls. RESULTS: Missense mutations were found in SCN5A in 13 of 584 patients (2.2%, probands). Diarrhea-predominant IBS was the most prevalent form of IBS in the overall study population (25%). However, a greater percentage of individuals with SCN5A mutations had constipation-predominant IBS (31%) than diarrhea-predominant IBS (10%; P < .05). Electrophysiologic analysis showed that 10 of 13 detected mutations disrupted Na(V)1.5 function (9 loss-of-function and 1 gain-of-function function). The p. A997T-Na(V)1.5 had the greatest effect in reducing Na(V)1.5 function. Incubation of cells that expressed this variant with mexiletine restored their sodium current and administration of mexiletine to 1 carrier of this mutation (who had constipation-predominant IBS) normalized their bowel habits. In the genome-wide association study and 4 replicated studies, the SCN5A locus was strongly associated with IBS. CONCLUSIONS: About 2% of patients with IBS carry mutations in SCN5A. Most of these are loss-of-function mutations that disrupt Na(V)1.5 channel function. These findings provide a new pathogenic mechanism for IBS and possible treatment options.
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| 4. |
- Björnsson, Einar, et al.
(författare)
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The natural history of small duct primary sclerosing cholangitis
- 2008
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Ingår i: Gastroenterology. - : Elsevier BV. - 1528-0012 .- 0016-5085. ; 134:4, s. 975-980
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Tidskriftsartikel (refereegranskat)abstract
- Background & Aims: The long-term prognosis of patients with small-duct primary sclerosing cholangitis (PSC) remains incompletely characterized. We aimed at determining the natural history and long-term outcomes of a large number of patients with small-duct PSC. Methods: Data from 83 patients with well-characterized small-duct PSC from several medical institutions in Europe and the United States were combined. Each patient with small-duct PSC was randomly matched to 2 patients with large-duct PSC by age, gender, calendar year of diagnosis, and institution. Results: The median age at diagnosis in both groups was 38 years (61% males). Nineteen (22.9%) of the 83 patients with small-duct PSC progressed to large-duct PSC in a median of 7.4 (interquartile range [IQR], 5.1–14) years. One patient with small-duct PSC who progressed to large-duct PSC was diagnosed with cholangiocarcinoma but after progression to large-duct PSC; 20 patients with large-duct PSC developed cholangiocarcinoma. Patients with small-duct PSC had a significantly longer transplantation-free survival compared with large-duct PSC patients (13 years [IQR, 10–17] vs 10 years [IQR, 6–14], respectively; hazard ratio, 3.04; 95% confidence interval: 1.82–5.06; P < .0001). Two patients with small-duct PSC who underwent liver transplantation had recurrence of small-duct PSC in the graft 9 and 13 years, respectively, after transplantation. Conclusions: Small-duct PSC is a disease of progressive potential but associated with a better long-term prognosis as compared with large-duct PSC. Small-duct PSC may recur after liver transplantation. Cholangiocarcinoma does not seem to occur in patients with small-duct PSC, unless the disease has progressed to large-duct PSC.
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| 5. |
- Chen, D, et al.
(författare)
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Altered control of gastric acid secretion in gastrin-cholecystokinin double mutant mice
- 2004
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Ingår i: Gastroenterology. - : Elsevier BV. - 1528-0012 .- 0016-5085. ; 126:2, s. 476-487
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Tidskriftsartikel (refereegranskat)abstract
- Background & Aims: Three pathways control gastric acid secretion: the gastrin-enterochromaffin-like (ECL) cell axis, the vagus-parietal cell axis, and the cholecystokinin (CCK)-D cell axis. Mice lacking gastrin or both gastrin and CCK were examined to determine the role of the hormones. Methods: Acid was measured after pylorus ligation, and biopsies from gastrin knockout (KO), gastrin-CCK double-KO, and wild-type (WT) mice were collected for biochemical, immunocytochemical, and electron-microscopic examination. Results: The ECL cells were inactive in both groups of mutant mice but the cell number was unaffected. Both parietal cell number and level of H+/K+-ATPase messenger RNA (mRNA) were reduced in the mutant strains, but gastrin-CCK double-KO mice displayed more active parietal cells and larger acid output than the gastrin KO mice. The acid response to histamine in double-KO mice was unchanged whereas that to gastrin was diminished, but it could be restored by infusion of gastrin. Oxyntic D-cell density was the same in both mutant strains, but the D cells were more active in the gastrin KO than in the double-KO mice. CCK infusion in gastrin-CCK double-KO mice raised the somatostatin mRNA level and inhibited acid secretion to the level seen in gastrin KO mice. Vagotomy and atropine abolished acid secretion in all 3 groups of mice. Conclusions: Lack of gastrin impairs the gastrin-ECL axis, whereas lack of gastrin and CCK impairs both hormonal pathways. In the gastrin-CCK double-KO mice, acid secretion is only controlled by cholinergic vagal stimulation, which normalizes the acid output.
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| 6. |
- Chen, DA, et al.
(författare)
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Differentiation of gastric ECL cells is altered in CCK2 receptor-deficient mice
- 2002
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Ingår i: Gastroenterology. - : Elsevier BV. - 1528-0012 .- 0016-5085. ; 123:2, s. 577-585
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Tidskriftsartikel (refereegranskat)abstract
- Background & Aims: Gastrin stimulation of the type 2 cholecystokinin (CCK2) receptor results in ECL cell proliferation and histamine secretion. This report describes the effects of targeted disruption of the CCK2 receptor gene on ECL cell morphology and function. Methods: The ECL cells in the oxyntic mucosa of CCK2 receptor-deficient (knockout [KO]) vs. wild-type (WT) mice were investigated by immunocytochemical and biochemical approaches, as well as by electron microscopy. Results: Immunocytochemistry demonstrates similar numbers (cells per millimeter of horizontal length of mucosa) of pancreastatin- or vesicle monoamine transporter-2 (VMAT-2)-immunoreactive cells in WT mice and KO mice. However, only WT mice harbor histamine-immunoreactive ECL cells. The mucosal histamine content in KO mice (likely originating from mast cells) is only a minute fraction of that present in WT animals. The activity of the histamine forming enzyme, histidine decarboxylase (a marker of ECL cells), was undetectable in the oxyntic mucosa of KO mice yet was readily apparent in the mucosa from WT animals. Electron microscopy revealed numerous ECL cells in WT mice. In KO animals, these cells were replaced by an "ECL-like" cell type, characterized by a lack of secretory vesicles (a hallmark feature of normal ECL cells) and the presence of dense-core granules and microvesicles in numbers comparable to those found in WT ECL cells. Based on ultrastructural features, the ECL-like cells in KO mice can be readily distinguished from other gastric endocrine cells, including A-like cells and D cells. Conclusions: Absence of a single gene product, the CCK2 receptor, alters the differentiation and function of gastric ECL cells.
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| 7. |
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| 8. |
- Elmberg, Maria, et al.
(författare)
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Increased Mortality Risk in Patients With Phenotypic Hereditary Hemochromatosis But Not in Their First-Degree Relatives
- 2009
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Ingår i: Gastroenterology. - : Elsevier BV. - 0016-5085 .- 1528-0012. ; 137:4, s. 1301-1309
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND & AIMS: Hereditary hemochromatosis (HH) is an autosomal-recessive disorder characterized by iron overload. Relatives of HH patients were screened and those with HH-associated mutations and an increased iron load were identified. However, little is known about their mortality or strategies for their management. We assessed mortality among Swedish patients with HH and their first-degree relatives using health and census registers. METHODS: We performed a matched population-based cohort study of 3832 patients with HH and their 14,496 first-degree relatives using data collected from 1990 through 2007. Mortality data from these groups were compared with that of 38,969 population controls and their 143,349 first-degree relatives using Cox regression analyses. RESULTS: Patients identified on the basis of hospitalization with HH had an increased risk (relative risk [RR]) for death (RR, 2.45; 95% confidence interval [CI], 2.27-2.64; 857 deaths). Patients identified through other means had a mortality risk that was lower than those identified in the hospital but higher than controls (RR, 1.15; 95% CI, 1.00-1.33; 216 deaths). Their first-degree relatives had only a marginally increased mortality risk (RR, 1.05; 95% CI, 1.01-1.10); this RR was similar to that of patients' spouses (RR, 1.09; 95% CI, 0.86-1.38; 82 deaths). Patients with HH who also had a family history of HH did not have an increased mortality risk compared with other groups (RR, 1.05; 95% CI 0.67-1.62; 21 deaths). CONCLUSIONS: Patients with HH have a modestly increased mortality risk compared with controls. The mortality of relatives is increased marginally compared with controls, and is similar among biological and nonbiological relatives.
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| 9. |
- Friis-Hansen, Lennart, et al.
(författare)
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Gastric inflammation, metaplasia, and tumor development in gastrin-deficient mice
- 2006
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Ingår i: Gastroenterology. - : Elsevier BV. - 1528-0012 .- 0016-5085. ; 131:1, s. 246-258
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Tidskriftsartikel (refereegranskat)abstract
- Background & Aims: Gastrin deficiency and proton pump inhibitor treatment cause achlorhydria, which predisposes to disease. To elucidate the underlying molecular biology, we examined the changes in gastric gene expression in both types of achlorhydria. We also explored the associated changes in the gastric microflora and the long-term consequences of gastrin-deficient achlorhydria. Methods: Expression profiles were generated from gastric RNA from wild-type mice, gastrin knockout (KO) mice, gastrin KO mice after I week of gastrin infusion, and wild-type mice treated for I month with a proton pump inhibitor. The results were confirmed using real-time polymerase chain reaction and immuno-histochemistry. Selective media were used to characterize the gastric microflora. Results: The number of gastric bacteria was increased in both gastrin KO and PPI-treated mice. The expression profiles revealed activation of immune defense genes, interferon-regulated response genes, and intestinal metaplasia of the gastric mucosa. In young gastrin-deficient mice, gastrin infusions reversed the changes. Over time, the changes accumulated, became irreversible, and progressed into metaplasia and polyp development. Finally, the study showed that gastrin regulated the expression of genes encoding extracellular matrix proteins. Conclusions: Independently of gastrin, achlorhydria is associated with gastric bacterial overgrowth and intestinal gene expression patterns and is associated with predisposition to disease. Gastrin is therefore essential for prevention of gastric disease, mainly through control of acid secretion but to a lesser extent also through control of gastric gene expression. The gastrin-deficient mouse serves as a useful new model for gastric metaplasia and neoplasia.
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| 10. |
- Huang, Wuqing, et al.
(författare)
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Use of Phosphodiesterase 5 Inhibitors Associates With Risk of Colorectal Cancer in Men With Benign Colorectal Neoplasms
- 2019
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Ingår i: Gastroenterology. - : Elsevier BV. - 1528-0012 .- 0016-5085. ; 157:3, s. 672-681
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND & AIMS: Phosphodiesterase 5 (PDE5) inhibitors have been proposed to have chemopreventative effects on colorectal cancer (CRC), although data are needed from population-based studies. We performed a nationwide cohort study to investigate the association between use of PDE5 inhibitors and risk of CRC in men with benign colorectal neoplasms.METHODS: We identified men who received a diagnosis of benign colorectal neoplasm from July 2005 through March 2015 that were listed in the Swedish Hospital Discharge Register. We linked data with those from other national Swedish registers to obtain information about prescription of PDE5 inhibitors and CRC diagnoses. Cox regression was used to calculate hazard ratios (HRs) and 95% CIs.RESULTS: A total of 4823 patients were prescribed with PDE5 inhibitors during the study period; the incidence rate of CRC was 2.64 per 1000 person-years for men prescribed PDE5 inhibitors compared to 4.46 per 1000 person-years for men without a prescription. We found a significant negative association between PDE5 inhibitor use and risk of CRC (adjusted HR, 0.65; 95% CI, 0.49-0.85); the decreased risk of CRC was associated with an increased cumulative dose of PDE5 inhibitors (P=.003). PDE5 prescription was associated with greater reduction in risk for advanced-stage CRC (adjusted HR, 0.61; 95% CI, 0.37-1.00) than early-stage CRC (adjusted HR, 0.70; 95% CI, 0.50-0.98), but the difference was not significant.CONCLUSIONS: In a nationwide population-based study of men with a diagnosis of benign colorectal neoplasm in Sweden, we found evidence that use of PDE5 inhibitors associates with a reduced risk of CRC. Further studies are needed to confirm the observed association.
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