Helicobacter pylori and Epstein-Barr Virus Co-Infection in Gastric Disease: What Is the Correlation with p53 Mutation, Genes Methylation and Microsatellite Instability in a Cohort of Sicilian Population?

Genetic predisposition, environmental factors, and infectious agents interact in the development of gastric diseases. Helicobacter pylori (Hp) and Epstein-Barr virus (EBV) infection has recently been shown to be correlated with these diseases. A cross-sectional study was performed on 100 hospitalized Italian patients with and without gastric diseases. The patients were stratified into four groups. Significant methylation status differences among CDH1, DAPK, COX2, hMLH1 and CDKN2A were observed for coinfected (Hp-EBV group) patients; particularly, a significant presence of COX2 (p = 0.0179) was observed. For microsatellite instability, minor stability was described in the Hp-HBV group (69.23%, p = 0.0456). Finally, for p53 mutation in the EBV group, exon 6 was, significantly, most frequent in comparison to others (p = 0.0124), and in the Hp-EBV group exon 8 was, significantly, most frequent in comparison to others (p < 0.0001). A significant positive relationship was found between patients with infection (Hp, EBV or both) and p53 mutation (rho = 0.383, p = 0.0001), methylation status (rho = 0.432, p < 0.0001) and microsatellite instability (rho = 0.285, p = 0.004). Finally, we observed among infection and methylation status, microsatellite instability, and p53 mutation a significant positive relationship only between infection and methylation status (OR = 3.78, p = 0.0075) and infection and p53 mutation (OR = 6.21, p = 0.0082). According to our analysis, gastric disease in the Sicilian population has different pathways depending on the presence of various factors, including infectious agents such as Hp and EBV and genetic factors of the subject.

An aqueous extract from Artemisia capillaris inhibits acute gastric injury through mucosal stabilization.

BACKGROUND: Artemisia capillaris is among the most abundantly used traditional medicines, utilized in East Asia to treat diverse illnesses, including gastrointestinal tract diseases. We previously reported that an aqueous extract of A. capillaris (AEAC) inhibited gastric inflammation induced by HCl/ethanol via reactive oxygen species scavenging and NF-κB downregulation. To date, the pharmacological potential of AEAC for promoting mucosal integrity has not been studied. RESULTS: Here, we report that a single treatment with AEAC increased mucus production, and repeated administration of AEAC abolished HCl/ethanol-induced mucosal injury in vivo. Single- and multiple-dose AEAC treatments measurably increased the expression of mucosal stabilizing factors in vivo, including mucin (MUC) 5 AC, MUC6, and trefoil factor (TFF) 1 and TFF2 (but not TFF3). AEAC also induced mucosal stabilizing factors in both SNU-601 cells and RGM cells through phosphorylation of extracellular signal-regulated kinases. CONCLUSION: Taken together, our results suggest that AEAC protects against HCl/ethanol-induced gastritis by upregulating MUCs and TFFs and stabilizing the mucosal epithelium. © 2021 Society of Chemical Industry.

Role of nucleotide binding oligomerization domain-like receptor protein 3 inflammasome in stress-induced gastric injury.

BACKGROUND AND AIM: The inflammasomes promote pro-caspase-1 cleavage, leading to processing of pro-interleukin (IL)-1ß into its mature form. We investigated the role of the IL-1ß and nucleotide binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome in gastric injury in mice receiving water-immersion restraint stress (WIRS), focusing on the cyclooxygenase (COX)-2/prostaglandin (PG) E2 axis. METHODS: To induce gastric injury, the mice were placed in a restraint cage and immersed in the water bath to the level of the xiphoid process. Protein levels of mature caspase-1 and IL-1ß were assessed by western blotting. RESULTS: Water-immersion restraint stress induced gastric injury with increase in IL-1ß expression by activation of NLRP3 inflammasome. Exogenous IL-1ß attenuated the injury, whereas anti-IL-1ß neutralizing antibody and IL-1ß receptor antibody aggravated it. NLRP3-/- and caspase-1-/- mice enhanced the injury with reducing of mature IL-1ß, and this aggravation was reduced by exogenous IL-1ß supplementation. Toll-like receptor 4-/- mice were hyporesponsive to WIRS in terms of mature IL-1ß production. Rabeprazole attenuated the injury with preventing inflammasome activation. WIRS injured the stomach with promotion of COX-2 mRNA and PGE2 production, and exogenous IL-1ß enhanced these molecules, while IL-1ß immunoneutralization exerted opposite effect. PGE2 supplementation abolished the hypersensitivity in NLRP3-/- and caspase-1-/- mice through negative regulation of inflammatory cytokines. CONCLUSION: These results suggest that NLRP3 inflammasome-derived IL-1ß plays a protective role in stress-induced gastric injury via activation of the COX-2/PGE2 axis. Toll-like receptor 4 signaling and gastric acid may be involved in NLRP3 inflammasome activation.

Irsogladine maleate alters expression of a tight junction protein in portal hypertensive gastropathy.

BACKGROUND AND AIM: Portal hypertensive gastropathy (PHG) is characterized by noninflammatory edema and vasodilatation of the lamina propria of the mucosal epithelium. In addition, the alterations of intercellular junction proteins and dilatation of the endothelial gaps have been reported. In this study, we examined whether irsogladine maleate (IM), a gastric mucosal protective agent, has the potential to improve PHG by restoration of tight junctions (TJs). METHODS: Twenty-four patients with PHG were registered and randomly assigned into two groups: 12 patients in the IM-administration group and 12 patients in the non-administration group. In the administration group, IM (4 mg/day) was administered orally for 12 weeks. Gastric mucosa with a red color in patients with PHG were obtained endoscopically on the registration day and 12 weeks later. The endoscopic findings were evaluated, an immunohistochemical analysis of claudin-3 (a TJ protein) expression in gastric mucosal tissues by a laser microscope was performed, and claudin-3 expression was quantified by western blot analysis. RESULTS: Irsogladine maleate improved the degree of PHG in 2/12 patients endoscopically, in contrast to none of the 12 patients in the non-administration group. Immunohistochemical analysis showed that expression of claudin-3 increased in 8/12 patients in the IM-administration group and 2/12 patients in the non-administration group (P = 0.036). Western blot analysis revealed that the increase in claudin-3 after 12 weeks was significantly higher in the IM-administration group than in the non-administration group (P = 0.010). CONCLUSIONS: The present pilot study suggested that IM might improve the gastric mucosa in PHG through restoration of TJ-protein claudin-3.

An LCM-based genomic analysis of SPEM, Gastric Cancer and Pyloric Gland Adenoma in an Asian cohort.

Spasmolytic polypeptide-expressing metaplasia (SPEM) and pyloric gland adenoma (PGA) in the stomach are metaplastic and neoplastic lesions, respectively, in which gastric body glands are replaced by pyloric glands. The aim of this study was to evaluate the genomic profile of SPEM and compare it with intestinal-type gastric cancer (GC) and PGA. Thirteen gastrectomies showing PGA with or without dysplasia, GC and SPEM were retrospectively selected. MUC5AC, MUC6, gastrin, and TFF2 IHC were performed. Lesions were subjected to laser capture microdissection followed by DNA extraction. Forty-three DNA samples were extracted from PGA without cytological dysplasia, PGA with low-grade and high-grade dysplasia and pyloric gland adenocarcinoma, GC, SPEM, and adjacent normal tissue from the body of the stomach and were subjected to exome sequencing for 49 genes that are commonly dysregulated in GC. Sanger sequencing was performed for confirmation. Twenty nonsynonymous mutations were identified in SPEM, and none of these were frameshifts or indels. PGA with or without cytological dysplasia showed a significantly higher number of mutations compared with SPEM. As cytological dysplasia increased from no dysplasia to dysplasia in PGA, the percentage of frameshift mutations, indels, and missense variations increased. Further missense or frameshift mutations were observed in the KRAS, APC, TP53, and CTNNB1 genes in the PGA group. In GC, mutations were observed in the TP53 gene (p.Arg248Gln). Missense mutations in the MUC5AC, KRAS, BRAF, and EZH2 genes were common between SPEM and GC. SPEM showed fewer genomic variations than GC and PGA, and was genomically distinct from the pyloric epithelium in PGA. Stepwise progression of PGA from PGA without dysplasia to PGA with dysplasia/adenocarcinoma was associated an increase in mutations. SPEM appears to be more genomically similar to GC than PGA.

Activated Braf induces esophageal dilation and gastric epithelial hyperplasia in mice.

Germline mutations in BRAF are a major cause of cardio-facio-cutaneous (CFC) syndrome, which is characterized by heart defects, characteristic craniofacial dysmorphology and dermatologic abnormalities. Patients with CFC syndrome also commonly show gastrointestinal dysfunction, including feeding and swallowing difficulties and gastroesophageal reflux. We have previously found that knock-in mice expressing a Braf Q241R mutation exhibit CFC syndrome-related phenotypes, such as growth retardation, craniofacial dysmorphisms, congenital heart defects and learning deficits. However, it remains unclear whether BrafQ241R/+ mice exhibit gastrointestinal dysfunction. Here, we report that BrafQ241R/+ mice have neonatal feeding difficulties and esophageal dilation. The esophagus tissues from BrafQ241R/+ mice displayed incomplete replacement of smooth muscle with skeletal muscle and decreased contraction. Furthermore, the BrafQ241R/+ mice showed hyperkeratosis and a thickened muscle layer in the forestomach. Treatment with MEK inhibitors ameliorated the growth retardation, esophageal dilation, hyperkeratosis and thickened muscle layer in the forestomach in BrafQ241R/+ mice. The esophageal dilation with aberrant skeletal-smooth muscle boundary in BrafQ241R/+ mice were recovered after treatment with the histone H3K27 demethylase inhibitor GSK-J4. Our results provide clues to elucidate the pathogenesis and possible treatment of gastrointestinal dysfunction and failure to thrive in patients with CFC syndrome.

Epidemiological characterization, genetic alterations of Helicobacter pylori infection in chronic gastric disorder and prognostic values of heterozygosity loss in chromosome 3p.

From the literature review, there seem to be no studies conducted on infection caused by Helicobacter pylori in patients with gastric MALT lymphoma in the KSA region. The present research is an attempt to understand the prevalence of patients infected with H. pylori in the selected region and the role of allelic imbalance of chromosome 3p regions to understand the clinical manifestations and features associated with MALT lymphomagenesis. The researcher analyzed the frequency of infection in patients from the region of Saudi Arabia by examining the data collected from hospitals and biopsy tissue samples as per the recommended protocol. The endoscopic diagnosis was performed to collect biopsy samples. Histology and AP-PCR DNA fingerprinting analyses were performed from the endoscopic gastric mucosal biopsies collected from patients with associated gastric MALT lymphoma. The existence of H. pylori was examined based on the results of gastric mucosal biopsies stained with hematoxylin-eosin (H&E) and Steiner's silver stains. MALT, MALT lymphoma tissue samples and H. pylori-positive chronic gastritis were examined for LOH at chromosome 3p24 using standard procedures and techniques. The findings of the paper revealed the H. pylori was found to be positive in 17% of the cases significantly high among the age group of 31-50 years. Patients with MALT, MALT lymphoma, and H. pylori-associated gastritis presented features such as lymphocyte accumulation, vacuolation, Peyer's patch appearance, and lymphatic follicles. H. pylori were found to appear as a dense colored accumulated mass in the gastric epithelial layer. The findings from AP-PCR generated DNA fingerprints revealed intense band including two prominent bands in MALT lymphoma. Among other loci, 3p24 was the only one locus that showed high percentages of LOH as reported earlier in all cancer-related cases. The findings of this research paper empower the fact that allelic imbalances play a vital role in the development of MALT lymphoma. However, future researches should be conducted to identify the chromosome regions of the AP-PCR generated DNA fingerprints of human gastric MALT lymphoma in order to confirm this proposition.

A quarter of patients with type 1 diabetes have co-existing non-islet autoimmunity: the findings of a UK population-based family study.

Individuals with type 1 diabetes (T1D) are at increased risk of coeliac disease (CD), autoimmune thyroiditis and autoimmune gastritis, but the absolute risks are unclear. The aim of this study was to investigate the prevalence of autoantibodies to tissue transglutaminase (TGA), thyroid peroxidase (TPOA) and gastric H+ /K+ -ATPase (ATPA) and their genetic associations in a well-characterized population-based cohort of individuals with T1D from the Bart's-Oxford family study for whom islet autoantibody prevalence data were already available. Autoantibodies in sera from 1072 patients (males/females 604/468; median age 11·8 years, median T1D duration 2·7 months) were measured by radioimmunoassays; HLA class II risk genotype was analysed in 973 (91%) using polymerase chain reaction with sequence specific primers (PCR-SSP). The prevalence of TGA (and/or history of CD), TPOA and ATPA in patients was 9·0, 9·6 and 8·2%, respectively; 3·1% had two or more autoantibodies. Females were at higher risk of multiple autoimmunity; TGA/CD were associated with younger age and TPOA with older age. ATPA were uncommon in patients under 5 years, and more common in older patients. Anti-glutamate decarboxylase autoantibodies were predictive of co-existing TPOA/ATPA. TGA/CD were associated with human leucocyte antigen (HLA) DR3-DQ2, with the DR3-DQ2/DR3-DQ2 genotype conferring the highest risk, followed by DR4-DQ8/DR4-DQ8. ATPA were associated with DR3-DQ2, DRB1*0404 (in males) and the DR3-DQ2/DR4-DQ8 genotype. TPOA were associated with the DR3-DQ2/DR3-DQ2 genotype. Almost one-quarter of patients diagnosed with T1D aged under 21 years have at least one other organ-specific autoantibody. HLA class II genetic profiling may be useful in identifying those at risk of multiple autoimmunity.

Human and Helicobacter pylori Interactions Determine the Outcome of Gastric Diseases.

The innate immune response is a critical hallmark of Helicobacter pylori infection. Epithelial and myeloid cells produce effectors, including the chemokine CXCL8, reactive oxygen species (ROS), and nitric oxide (NO), in response to bacterial components. Mechanistic and epidemiologic studies have emphasized that dysregulated and persistent release of these products leads to the development of chronic inflammation and to the molecular and cellular events related to carcinogenesis. Moreover, investigations in H. pylori-infected patients about polymorphisms of the genes encoding CXCL8 and inducible NO synthase, and epigenetic control of the ROS-producing enzyme spermine oxidase, have further proven that overproduction of these molecules impacts the severity of gastric diseases. Lastly, the critical effect of the crosstalk between the human host and the infecting bacterium in determining the severity of H. pylori-related diseases has been supported by phylogenetic analysis of the human population and their H. pylori isolates in geographic areas with varying clinical and pathologic outcomes of the infection.

A genome-wide association study for left-sided displacement of the abomasum using a high-density single nucleotide polymorphism array.

Left-sided displacement of the abomasum (LDA) is a frequent disease in dairy cattle causing significant financial losses for dairy farmers. Heritability (h2) of this complex disease was estimated at up to 0.5 in German Holstein (GH) cattle. Using the Bovine High Density BeadChip (Illumina Inc., San Diego, CA) comprising 588,753 single nucleotide polymorphisms (SNP) after quality control for 126 LDA cases and 280 population-based controls, we used a mixed linear model analysis in a genome-wide association study (GWAS). We identified 6 genomic regions for LDA on bovine chromosomes 2, 8, 13, 20, 24, and X that were significantly associated with LDA. Each of these regions was covered by 4 to 12 LDA-associated SNP. Single SNP within these regions explained up to 7.3% of the phenotypic variance. An independent sample of 1,554 GH cows, including 539 controls and 1,015 cases, were genotyped for 8 SNP highly associated with LDA on Bos taurus autosomes (BTA) 2, 8, 13, and 24, as well as 6 SNP located in previously identified LDA regions on BTA1, 5, 11, and 27 using competitive allele-specific PCR genotyping technology (KASP). The analysis using the KASP genotypes confirmed LDA-associated loci on BTA2, 8, 13, and 27. These genomic regions may contribute to the susceptibility to LDA in Holstein cows and may harbor functional variants for LDA.

Activating GNAS and KRAS mutations in gastric foveolar metaplasia, gastric heterotopia, and adenocarcinoma of the duodenum.

BACKGROUND: Heterotopic gastric-type epithelium, including gastric foveolar metaplasia (GFM) and gastric heterotopia (GH), is a common finding in duodenal biopsy specimens; however, there is still controversy regarding their histogenetic backgrounds. METHODS: We analysed a total of 177 duodenal lesions, including 66 GFM lesions, 81 GH lesions, and 30 adenocarcinomas, for the presence of GNAS, KRAS, and BRAF mutations. RESULTS: Activating GNAS mutations were identified in 27 GFM lesions (41%) and 23 GH lesions (28%). The KRAS mutations were found in 17 GFM lesions (26%) and 2 GH lesions (2%). A BRAF mutation was found in only one GFM lesion (2%). These mutations were absent in all 32 normal duodenal mucosa specimens that were examined, suggesting a somatic nature. Among the GFM lesions, GNAS mutations were more common in lesions without active inflammation. Analyses of adenocarcinomas identified GNAS and KRAS mutations in 5 (17%) and 11 lesions (37%), respectively. Immunohistochemically, all the GNAS-mutated adenocarcinomas diffusely expressed MUC5AC, indicating gastric epithelial differentiation. CONCLUSIONS: A significant proportion of GFM and GH harbours GNAS and/or KRAS mutations. The common presence of these mutations in duodenal adenoma and adenocarcinoma with a gastric epithelial phenotype implies that GFM and GH might be precursors of these tumours.

Familial Gastric Cancers.

Although the majority of gastric carcinomas are sporadic, approximately 10% show familial aggregation, and a hereditary cause is determined in 1%-3% cases. Of these, hereditary diffuse gastric cancer is the most recognized predisposition syndrome. Although rare, the less commonly known syndromes also confer a markedly increased risk for development of gastric cancer. Identification and characterization of these syndromes require a multidisciplinary effort involving oncologists, surgeons, genetic counselors, biologists, and pathologists. This article reviews the molecular genetics, clinical and pathologic features, surveillance guidelines, and preventive measures of common and less common hereditary gastric cancer predisposition syndromes.

Indian Hedgehog mediates gastrin-induced proliferation in stomach of adult mice.

BACKGROUND & AIMS: Loss of expression of Sonic Hedgehog (Shh) from parietal cells results in hypergastrinemia in mice, accompanied by increased expression of Indian Hedgehog (Ihh) and hyperproliferation of surface mucous cells. We investigated whether hypergastrinemia induces gastric epithelial proliferation by activating Ihh signaling in mice. METHODS: We studied mice with parietal cell-specific deletion of Shh (PC-Shh(KO)) and hypergastrinemia, crossed with gastrin-deficient (GKO) mice (PC-Shh(KO)/GKO). When mice were 3-4 months old, gastric tissues were collected and analyzed by histology, for incorporation of bromodeoxyuridine, and for expression of the surface mucous cell marker Ulex europaeus. PC-Shh(KO)/GKO mice were given gastrin infusions for 7 days; gastric surface epithelium was collected and expression of Ihh was quantified by laser capture microdissection followed by quantitative reverse transcriptase polymerase chain reaction. Mouse stomach-derived organoids were incubated with or without inhibitors of WNT (DKK1) or Smoothened (vismodegib) and then cocultured with immortalized stomach mesenchymal cells, to assess proliferative responses to gastrin. RESULTS: Gastric tissues from PC-Shh(KO)/GKO mice with hypergastrinemia had an expanded surface pit epithelium, indicated by a significant increase in numbers of bromodeoxyuridine- and Ulex europaeus-positive cells, but there was no evidence for hyperproliferation. Gastrin infusion of PC PC-Shh(KO)/GKO mice increased expression of Ihh and proliferation within the surface epithelium compared with mice given infusions of saline. In gastric organoids cocultured with immortalized stomach mesenchymal cells, antagonists of WNT and Smoothened inhibited gastrin-induced proliferation and WNT activity. Activity of WNT in media collected from immortalized stomach mesenchymal cells correlated with increased expression of glioma-associated oncogene homolog 1, and was inhibited by DKK1 or vismodegib. CONCLUSIONS: Ihh signaling mediates gastrin-induced proliferation of epithelial cells in stomachs of adult mice.

[Langerhans cell histiocytosis of the stomach with BRAF-V600E-mutation: case report and review of the literature]. / Langerhans-Zellhistiozytose des Magens mit BRAF-V600E-Mutation: Fallbericht und Literaturübersicht.

Langerhans cell histiocytosis is a disease with different clinical presentations and a wide spectrum of organ involvements. Rarely Langerhans cell histiocytosis can involve the gastrointestinal tract of adult patients. A case of infiltration of gastric mucosa by Langerhans cell histiocytosis is presented. The neoplastic nature of this infiltrate is underlined by the detection of a BRAF-V600E-mutation. Additionally, an overview of the so far 5 cases published in the English literature is provided. The published clinical experience indicates a benign curse of the disease.

Key role of endothelial importin-α in VEGF expression and gastric angiogenesis: novel insight into aging gastropathy.

Recent in vivo studies demonstrated that aging gastric mucosa has impaired angiogenesis and reduced expression of vascular endothelial growth factor (VEGF). Angiogenesis is triggered by hypoxia and VEGF gene activation, and the latter requires transport of transcription factor(s) into endothelial cell nuclei. We focused on gastric mucosal endothelial cells (GMEC), which are key targets and effectors of gastric angiogenesis, and determined whether and to what extent importin-α, a nuclear transport protein, regulates VEGF gene activation and gastric angiogenesis and the possible role of importin-α in aging gastropathy. GMEC were isolated from rats 3 and 24 mo of age, young (YGEC) and aging (AGEC), respectively. We examined in these cells 1) in vitro angiogenesis, 2) expression of VEGF and importin-α, 3) nuclear transport of hypoxia-inducible factor (HIF)-1α by importin-α, 4) binding of HIF-1α to the VEGF gene promoter, and 5) effects of importin-α silencing in YGEC and its upregulation in AGEC on angiogenesis and VEGF expression. AGEC exhibited significantly impaired in vitro angiogenesis by fourfold and decreased expression of VEGF, importin-α, and nuclear HIF-1α by 1.4-fold, 1.6-fold, and 2.9-fold, respectively, vs. YGEC. Upregulation of importin-α in AGEC significantly reversed all these abnormalities. In YGEC, knockdown of importins-α1 and -α3 significantly reduced in vitro angiogenesis by 93% and 73% and VEGF expression by 48% and 52%, respectively. The above findings demonstrate that importin-α is a novel and critical regulator of gastric angiogenesis. Its reduced expression in AGEC is the key mechanism for impaired angiogenesis and reduced VEGF.

Gastrointestinal mucosal involvement without amyloidosis in children with familial Mediterranean fever.

BACKGROUND AND OBJECTIVES: Familial Mediterranean fever (FMF) and inflammatory bowel disease togetherness is well described in the literature. Abdominal pain and various gastrointestinal manifestations may arise directly from FMF or secondary to FMF-associated diseases such as inflammatory bowel disease, vasculitidies, or amyloidosis. The aim of the study was to document gastrointestinal involvement in familial Mediterranean fever. METHODS: The medical files of the patients who were diagnosed as having FMF at the Department of Pediatric Gastroenterology, Gazi University School of Medicine between 2007 and 2012 were examined retrospectively. FMF diagnosis was made through performing clinical, laboratory, colonoscopy, endoscopy, and genetic analysis. RESULTS: Thirty-six patients were diagnosed as having FMF during this period. Among them, 11 patients were admitted with vomiting or diarrhea. Colonoscopy and upper gastrointestinal endoscopy were performed. Colonic inflammation and multiple gastric aphthous ulcerations were observed. CONCLUSIONS: In this report, we described 11 patients who presented with gastrointestinal symptoms and eventually diagnosed as having FMF. Gastrointestinal mucosal involvement without amyloidosis is documented by endoscopic and histopathologic investigations in these patients. We concluded that mucosal involvement of the gastrointestinal tract may be attack-related manifestations in these patients.

Abnormal expression of Toll-like receptor 4 is associated with susceptibility to ethanol-induced gastric mucosal injury in mice.

BACKGROUND AND AIMS: Toll-like receptor 4 (TLR4) contributes to ethanol-induced gastric mucosal injury. This study aimed to determine its precise role in this pathogenic state and the related signaling pathway. METHODS: Ethanol-induced gastric mucosal injury models were generated in TLR4(-/-) mice (C3H/HeJ: point mutation; C57BL/10ScNJ: gene deletion), their respective TLR4(+/+) wild-type counterparts, and heterozygous TLR4(+/-) mice. Lipopolysaccharide (LPS) or pyrrolidine dithiocarbamate (PDTC) was injected intraperitoneally 1 h or 30 min before ethanol administration. At 1 h post-ethanol treatment, gastric or serum specimens were evaluated. RESULTS: Ethanol intra-gastric administration induced significant gastric mucosal injury in all mice, but the damaged area was larger in TLR4(-/-) mice. LPS preconditioning and up-regulated TLR4 expression led to significantly larger areas of gastric mucosal damage. Upon ethanol administration, TLR4(+/+), and not TLR4(-/-), mice showed significant increases in TLR4, myeloid differentiation factor 88 (MyD88), cytoplasmic high mobility group box 1 (HMGB1), and nuclear factor-kappa B p65 (NF-κB p65). PDTC pretreatment significantly attenuated the ethanol-induced gastric mucosal damaged areas, inhibited nuclear NF-κB p65 expression, and suppressed HMGB1 translocation out of the nucleus. In addition, PDTC pretreatment reduced ethanol-stimulated expression of the inflammatory modulators, interleukin-1ß (IL-1ß) and tumor necrosis factor-alpha (TNF-α), in serum. CONCLUSIONS: Both deficient and excessive expression of TLR4 promotes ethanol-induced gastric mucosal injury. The underlying mechanism involves the MyD88/NF-κB signaling pathway and the HMGB1, TLR4 activator ligand. The increased expression of HMGB1 may lead to increased secretion and binding to TLR4, further stimulating the TLR4/MyD88/NF-κB signaling pathway and aggravating the ethanol-induced gastric mucosal injury.

Genetic associations of ketosis and displaced abomasum with milk production traits in early first lactation of Canadian Holsteins.

The aim of this study was to investigate the genetic associations of ketosis and displaced abomasum with milk production traits in early first lactation of Canadian Holsteins. Health data recorded by producers were available from the national dairy cattle health system in Canada. Test-day records of milk, fat, and protein yields were obtained from the routine milk recoding scheme. Ketosis and displaced abomasum were defined as binary traits (0 = healthy; 1 = sick) based on whether or not the cow had at least 1 case of the respective disease in the period from calving to 100 d after calving. Mean frequencies of ketosis and displaced abomasum were 4.1 and 2.7%, respectively. The following milk production traits were considered: milk yield, fat percentage (Fat%), protein percentage (Prot%), fat-to-protein (F:P) ratio, and F:P ratio >1.5. The trait F:P ratio >1.5 was scored as 1 or 0, based on whether or not the cow had an F:P ratio >1.5. For milk production traits, the first (5-30 d in milk) and the second (31-60 d in milk) test days were considered. Data were analyzed using bivariate linear animal models. Average heritabilities of 0.02 and 0.04 were obtained for ketosis and displaced abomasum, respectively. For milk production traits, the lowest heritabilities were obtained for F:P >1.5 (0.04 to 0.08), whereas the highest estimates were found for Prot% (0.27 to 0.38). Ketosis and displaced abomasum were genetically uncorrelated with milk yield in early lactation. Moderate favorable correlations were found between metabolic diseases and milk composition traits. Ketosis was significantly correlated with Fat% (0.33), F:P ratio (0.30), and F:P ratio >1.5 (0.35) at the first test day, whereas all genetic correlations with milk composition traits at the second test day were not significant and close to zero. Significant favorable genetic correlations were also found between displaced abomasum and F:P ratio (0.26), F:P ratio >1.5 (0.25) and Prot% (-0.19) at the first test day. Also, Prot% at the second test day was significantly correlated (-0.16) with displaced abomasum. Overall, a higher Fat% and F:P ratio and a lower Prot% at the first test day were associated with an increased susceptibility to metabolic diseases. As genetic correlations between metabolic diseases and F:P ratio were far from unity, dairy producers should be encouraged to keep accurate and complete health data. This will be expected to yield to more accurate genetic evaluations for metabolic diseases.

Keap1-null mutation leads to postnatal lethality due to constitutive Nrf2 activation.

Transcription factor Nrf2 (encoded by Nfe2l2) regulates a battery of detoxifying and antioxidant genes, and Keap1 represses Nrf2 function. When we ablated Keap1, Keap1-deficient mice died postnatally, probably from malnutrition resulting from hyperkeratosis in the esophagus and forestomach. Nrf2 activity affects the expression levels of several squamous epithelial genes. Biochemical data show that, without Keap1, Nrf2 constitutively accumulates in the nucleus to stimulate transcription of cytoprotective genes. Breeding to Nrf2-deficient mice reversed the phenotypic Keap1 deficiencies. These experiments show that Keap1 acts upstream of Nrf2 in the cellular response to oxidative and xenobiotic stress.

Genetic dissection reveals unexpected influence of beta subunits on KCNQ1 K+ channel polarized trafficking in vivo.

Targeted deletion of the Kcne2 potassium channel ß subunit gene ablates gastric acid secretion and predisposes to gastric neoplasia in mice. Here, we discovered that Kcne2 deletion basolaterally reroutes the Kcnq1 α subunit in vivo in parietal cells (PCs), in which the normally apical location of the Kcnq1-Kcne2 channel facilitates its essential role in gastric acid secretion. Quantitative RT-PCR and Western blotting revealed that Kcne2 deletion remodeled fundic Kcne3 (2.9±0.8-fold mRNA increase, n=10; 5.3±0.4-fold protein increase, n=7) but not Kcne1, 4, or 5, and resulted in basolateral Kcnq1-Kcne3 complex formation in Kcne2(-/-) PCs. Concomitant targeted deletion of Kcne3 (creating Kcne2(-/-)Kcne3(-/-) mice) restored PC apical Kcnq1 localization without Kcne1, 4, or 5 remodeling (assessed by quantitative RT-PCR; n=5-10), indicating Kcne3 actively, basolaterally rerouted Kcnq1 in Kcne2(-/-) PCs. Despite this, Kcne3 deletion exacerbated gastric hyperplasia in Kcne2(-/-) mice, and both hypochlorhydria and hyperplasia in Kcne2(+/-) mice, suggesting that Kcne3 up-regulation was beneficial in Kcne2-depleted PCs. The findings reveal, in vivo, Kcne-dependent α subunit polarized trafficking and the existence and consequences of potassium channel ß subunit remodeling.