Cannabinoid CB1 receptors are expressed by parietal cells of the human gastric mucosa.

Experimental data suggest that the endogenous cannabinoid system is involved in gastric function in different animal species. In most of them, CB(1) receptors have been localized on vagal terminals innervating the external wall of the stomach. We aimed at studying the putative presence and distribution of these receptors in the human gastric mucosa. To this end, we first performed Western blotting, RT-PCR, in situ hybridization, and immunohistochemical analysis of CB(1) protein distribution in biopsy samples of healthy individuals. To determine the precise cell populations expressing CB(1) receptors, we performed double immunofluorescence plus confocal microscopy analysis of the same samples. Our results show that CB(1) receptors are present in the gastric epithelium of the mucosa. Specifically, they are expressed by a subpopulation of mucosal cells, the acid-secreting parietal cells, as shown by double immunohistochemical staining and by their differential abundance in subregions of the gastric mucosa. These results reinforce the notion of a prominent role for the endocannabinoid system in the gastric function in humans and postulate the use of cannabinoid CB(1) receptors in parietal cells as new therapeutic targets for the regulation of gastric acid production.     

Mutations in the NRG1 gene are associated with Hirschsprung disease

Hirschsprung disease (HSCR, congenital colon aganglionosis) is a relatively common complex genetic condition caused by abnormal development of the enteric nervous system (ENS). Through a recent genome-wide association study conducted on Chinese HSCR patients, we identified a new HSCR contributing locus, neuregulin 1 (NRG1; 8p12), a gene known to be involved in the development of the ENS. As genes in which disease-associated common variants are found are to be considered as candidates for the search of deleterious rare variants (RVs) in the coding sequences, we sequenced the NRG1 exons of 358 sporadic HSCR patients and 333 controls. We identified a total of 13 different heterozygous RVs including 8 non-synonymous (A28G, E134K, V266L, H347Y, P356L, V486M, A511T, P608A) and 3 synonymous amino acid substitutions (P24P, T169T, L483L), a frameshift (E239fsX10), and a c.503-4insT insertion. Functional analysis of the most conserved non-synonymous substitutions, H347Y and P356L, showed uneven intracellular distribution and aberrant expression of the mutant proteins. Except for T169T and V486M, all variants were exclusive to HSCR patients. Overall, there was a statistically significant over-representation of NRG1 RVs in HSCR patients (p?=?0.008). We show here that not only common, but also rare variants of the NRG1 gene contribute to HSCR. This strengthens the role of NRG1.     

ROR1 is expressed in human breast cancer and associated with enhanced tumor-cell growth

Receptor-tyrosine-kinase-like orphan receptor 1 (ROR1) is expressed during embryogenesis and by certain leukemias, but not by normal adult tissues. Here we show that the neoplastic cells of many human breast cancers express the ROR1 protein and high-level expression of ROR1 in breast adenocarcinoma was associated with aggressive disease. Silencing expression of ROR1 in human breast cancer cell lines found to express this protein impaired their growth in vitro and also in immune-deficient mice. We found that ROR1 could interact with casein kinase 1 epsilon (CK1ε) to activate phosphoinositide 3-kinase-mediated AKT phosphorylation and cAMP-response-element-binding protein (CREB), which was associated with enhanced tumor-cell growth. Wnt5a, a ligand of ROR1, could induce ROR1-dependent signaling and enhance cell growth. This study demonstrates that ROR1 is expressed in human breast cancers and has biological and clinical significance, indicating that it may be a potential target for breast cancer therapy.     

FitSNPs: highly differentially expressed genes are more likely to have variants associated with disease

Background  

Candidate single nucleotide polymorphisms (SNPs) from genome-wide association studies (GWASs) were often selected for validation based on their functional annotation, which was inadequate and biased. We propose to use the more than 200,000 microarray studies in the Gene Expression Omnibus to systematically prioritize candidate SNPs from GWASs.     

FitSNPs: highly differentially expressed genes are more likely to have variants associated with disease

Background

Candidate single nucleotide polymorphisms (SNPs) from genome-wide association studies (GWASs) were often selected for validation based on their functional annotation, which was inadequate and biased. We propose to use the more than 200,000 microarray studies in the Gene Expression Omnibus to systematically prioritize candidate SNPs from GWASs.

Results

We analyzed all human microarray studies from the Gene Expression Omnibus, and calculated the observed frequency of differential expression, which we called differential expression ratio, for every human gene. Analysis conducted in a comprehensive list of curated disease genes revealed a positive association between differential expression ratio values and the likelihood of harboring disease-associated variants. By considering highly differentially expressed genes, we were able to rediscover disease genes with 79% specificity and 37% sensitivity. We successfully distinguished true disease genes from false positives in multiple GWASs for multiple diseases. We then derived a list of functionally interpolating SNPs (fitSNPs) to analyze the top seven loci of Wellcome Trust Case Control Consortium type 1 diabetes mellitus GWASs, rediscovered all type 1 diabetes mellitus genes, and predicted a novel gene (KIAA1109) for an unexplained locus 4q27. We suggest that fitSNPs would work equally well for both Mendelian and complex diseases (being more effective for cancer) and proposed candidate genes to sequence for their association with 597 syndromes with unknown molecular basis.

Conclusions

Our study demonstrates that highly differentially expressed genes are more likely to harbor disease-associated DNA variants. FitSNPs can serve as an effective tool to systematically prioritize candidate SNPs from GWASs.     

Cholesterol-related gene variants are associated with diabetes in coronary artery disease patients

Molecular Biology Reports - Coronary artery disease (CAD) which is a complex cardiovascular disease is the leading cause of death worldwide. The changing prevalence of the disease in different...     

Urocortin and corticotropin-releasing factor receptor expression in the human colonic mucosa

Urocortin is a newly identified member of the CRF neuropeptide family. Urocortin has been found to bind with high affinity to CRF receptors. The present study investigated urocortin and CRF receptor expression in human colonic mucosa. Non-pathologic sections of adult colorectal tissues were obtained from patients with colorectal cancer at surgery. Urocortin expression was examined using immunohistochemistry and messenger (m) RNA in situ hybridization. Isolated lamina propria mononuclear cells (LPMC) and epithelial cells were also analyzed by flow cytometry for the characterization of urocortin-positive cells, and by RT-PCR for detection of urocortin, CRF, and CRF receptor mRNA. Urocortin peptide distribution at various stages of human development (n = 35, from 11 weeks of gestation to 6 years of age) was examined by immunohistochemistry using surgical and autopsy specimens. Immunoreactive urocortin and urocortin mRNA were predominantly detected in lamina propria macrophages. Urocortin peptide expression was detected from as early as three months of age, but not before birth or in neonates. Urocortin, CRF receptor type 1 and type 2 mRNA were detected in LPMC. CRF receptor type 2β mRNA, a minor isoform in human tissues, was also detected in LPMC, but at lower levels. Urocortin is locally synthesized in lamina propria macrophages and may act on lamina propria inflammatory cells as an autocrine/paracrine regulator of the mucosal immune system. The appearance of urocortin after birth indicates that the exposure to dietary intake and/or luminal bacteria after birth may contribute to the initiation of urocortin expression in human gastrointestinal tract mucosa.     

Sialyl-Lewis x and Sialyl-Lewis a are associated with MUC1 in human endometrium

Endometrial epithelial cells express MUC1 with increased abundance in the secretory phase of the menstrual cycle, when embryo implantation occurs. MUC1 is associated with the apical surface of epithelial cells and is also secreted, being detectable in uterine fluid at elevated levels in the implantation phase. However, its physiological role is uncertain; it may either inhibit intercellular adhesion by steric hindrance or carry carbohydrate recognition structures capable of mediating cell-cell interaction. Here we show that endometrial epithelium expresses both Sialyl-Lewis x (SLe^x) and Sialyl-Lewis a (SLe^a), with a distribution and pattern of menstrual cycle regulation similar to that of MUC1. Using Western blotting and double determinant ELISA of uterine flushings, we demonstrate that SLe^x is associated with MUC1 core protein. The endometrial carcinoma cell lines HEC1A and HEC1B are shown to express MUC1 in a mosaic pattern, while three other cell lines express much lower amounts. HEC1A expresses both SLe^x and SLe^a while HEC1B expresses SLe^a only. Immunoprecipitation has been used to demonstrate that SLe^a is associated with MUC1 in HEC1B cells, and both SLe^x and SLe^a are associated with MUC1 in HEC1A cells.     

Fine structure of neurons synthesizing vasoactive intestinal peptide in the human colon from patients with Hirschsprung's disease

The fine structure of neuronal perikarya and processes containing VIP-like immunoreactive material in the colon of patients with Hirschsprung's disease was investigated by immunoelectron microscopy. No VIP-like immunoreactive terminals were found in Auerbach's plexus of the ganglionic segment. However, VIP-like immunoreactive preterminal axons were frequently found to make synaptic contact with both immunoreactive and non-immunoreactive elements within Meissner's plexus. Therefore, the function of the VIP neurons in Auerbach's plexus seems to differ from that in Meissner's plexus. In the oligoganglionic segment, there were a few VIP-like immunoreactive processes, but no VIP-like immunoreactive synaptic formations. VIP-like immunoreactive processes were rarely encountered in the aganglionic segment. In both the oligo- and aganglionic segments, bowel relaxation is considered to be disturbed due to the lack of synaptic contacts of VIP-like immunoreactive neurons with other neuronal components.     

Fine structure of neurons synthesizing vasoactive intestinal peptide in the human colon from patients with Hirschsprung's disease

Summary The fine structure of neuronal perikarya and processes containing VIP-like immunoreactive material in the colon of patients with Hirschsprung's disease was investigated by immunoelectron microscopy. No VIP-like immunoreactive terminals were found in Auerbach's plexus of the ganglionic segment. However, VIP-like immunoreactive preterminal axons were frequently found to make synaptic contact with both immunoreactive and non-immunoreactive elements within Meissner's plexus. Therefore, the function of the VIP neurons in Auerbach's plexus seems to differ from that in Meissner's plexus. In the oligoganglionic segment, there were a few VIP-like immunoreactive processes, but no VIP-like immunoreactive synaptic formations. VIP-like immunoreactive processes were rarely encountered in the aganglionic segment. In both the oligo-and aganglionic segments, bowel relaxation is considered to be disturbed due to the lack of synaptic contacts of VIP-like immunoreactive neurons with other neuronal components.This work was supported in part by a grant (no. 57370002) from the Ministry of Education, Science and Culture, Japan     

CYP1A1 *2B and *4 polymorphisms are associated with lung cancer susceptibility in Mexican patients

BACKGROUND: CYP1A1 is a gene involved in the high aryl hydrocarbon hydroxylase -inducible phenotype, which is a genetically-determined variation among individuals that has been associated with lung cancer risk. More specifically, CYP1A1 *2B and *4 polymorphisms have been associated with high susceptibility to lung cancer among cigarette smokers. MATERIALS AND METHODS: DNA was obtained from blood samples and we studied by PCR-RFLP the distribution of CYP1A1 *2B (n=248) and *4 (n=222) polymorphisms in healthy controls and 222 lung cancer patients from a Mexican population. RESULTS: Comparisons between groups showed an increased risk for lung cancer patients of *2B/*2B (18%; OR 7.6; 95% CI 3.0-19.2) and *4/ *4 genotypes (15%; OR 11.45; 95% CI 2.19-59.85) compared to the control group (1% for *2B/ *2B and 4.4% for *4/ *4). A significant association between lung cancer and homozygous *2B/ *2B passive smokers and *4/*4 ever (cigarettes) and passive smokers was also observed (p<0.05). Multivariate analysis revealed an increased risk for the *2B/*2B genotype (OR 6.83), as well as for *4/*4 (OR 28.8). CONCLUSION: The results of the study indicate a significant association between *2B/*2B and *4/*4 genotypes and the risk of developing lung cancer among Mexicans.     

Serum omentin-1 levels are inversely associated with the presence and severity of coronary artery disease in patients with metabolic syndrome

Context: Omentin-1, an adipokine secreted from visceral adipose tissue, has been reported to be associated with coronary artery disease (CAD) and metabolic disorders.

Objective: To clarify the relationship between serum omentin-1 levels and the presence and severity of CAD in patients with metabolic syndrome (MetS).

Methods: We measured serum omentin-1 levels in 175 consecutive patients with MetS and in 46 controls.

Results: Serum omentin-1 levels are inversely associated with the presence and angiographic severity of CAD in MetS patients.

Conclusions: Serum omentin-1 might be a potential biomarker to predict the development and progression of CAD in MetS patients.     

Microfibril-associated glycoprotein-1 and fibrillin-2 are associated with tropoelastin deposition in vitro

Elastic system fibers consist of microfibrils and tropoelastin. During development, microfibrils act as a template on which tropoelastin is deposited. Microfibril-associated glycoprotein-1 (MAGP-1) and fibrillin-2, the major components of microfibrils, provide the likely template for tropoelastin deposition. In this study, we used the RNA interference (RNAi) technique to establish MAGP-1 and fibrillin-2 gene-specific knock-downs individually in elastin-producing cells (human gingival fibroblasts). We then examined the extracellular deposition of tropoelastin by western blotting. These two genes were specifically suppressed to < 30% of the control level, and this was responsible for the diminution of tropoelastin deposition. An immunofluorescence study also confirmed that RNAi-mediated down-regulation of MAGP-1 or fibrillin-2 led to the loss of tropoelastin immunoreactivity. These results suggest that MAGP-1 and fibrillin-2 are, directly or indirectly, associated with the extracellular deposition of tropoelastin during elastic fiber formation in human gingival fibroblasts in vitro.