Hif-1α expression targets the TMA/Fmo3/TMAO axis to participate in gallbladder cholesterol stone formation in individuals living in plateau regions.

The incidence of gallbladder cholesterol stones (GCS) increases rapidly among people living in high-altitude hypoxic environments compared to those in normoxic areas. Upregulation of hepatic hypoxia inducible factor 1α (Hif-1α) plays a key role in the formation of GCS. High plasma trimethylamine-N-oxide (TMAO) levels are positively correlated with the occurrence of GCS. We hypothesized that HIF-1α may upregulate TMAO levels by promoting the transcription of flavin-containing monooxygenase 3 (Fmo3), which eventually leads to GCS formation. Our study shows that in women, high plasma total cholesterol and apolipoprotein B were positively correlated with cholecystolithiasis and hypoxia. Hif-1α binds to the Fmo3 promoter and promotes Fmo3 expression. Hypoxia and lithogenic diet induce the expression of Hif-1α, Fmo3, TMAO and cholesterol tube transporters in the livers of mice, disturb the proportion of bile and plasma components, and induce the formation of GCS. In cell experiments, silencing Hif-1α downregulates the expression of Fmo3, TMAO and cholesterol tube transporters. In a mouse model of hypoxic cholecystolithiasis, silencing Hif-1α downregulates the expression of related genes, restores the proportion of bile and plasma lipid components, and reduces the formation of GCS. Our study shows that Hif-1α binds to the promoter region of Fmo3 and promotes Fmo3 transcription. Thus, it mediates the transcriptional activation of the TMA/Fmo3/TMAO pathway, upregulates the expression of ATP-binding cassettes (Abc) g5 and g8, and participates in the regulation of the occurrence of GCS in the plateau region.

Hereditary liver disease: gallstones.

Gallstones are common in Western countries and due to pain and complications pose a substantial burden on health care systems. In general, cholesterol gallstones are distinguished from bilirubin gallstones. Bilirubin gallstones form if the ion product of unconjugated bilirubin and calcium in gallbladder bile exceeds the solubilisation capacities of mixed micelles and vesicles. Cholesterol gallstones develop if the amount of cholesterol in gallbladder bile exceeds the maximum concentration that is soluble at the given concentration of bile salts and phospholipids. In addition, cholesterol gallstone formation requires hypomotility of the gallbladder and a mucin gel as nucleation matrix for monohydrate crystals. The individual risk of gallstone formation is determined by interactions of lithogenic alleles of gallstone susceptibility genes and multiple environmental factors. For asymptomatic gallstones, expectant management is recommended, whereas an episode of gallstone-associated pain substantially increases the risk of complications such as cholecystitis, cholangitis and pancreatitis and therefore necessitates cholecystectomy.

MDR3 mutations associated with intrahepatic and gallbladder cholesterol cholelithiasis: an update.

BACKGROUND: The recurrent microlithiasis represents one of the most frequent clinical forms of lithiasis of the bile ducts. This affection is characterized by the presence of cholesterolic microgallstones on hepatic canaliculars, and belongs to a heterogeneous group of autosomal recessive liver disorders. Radiological diagnosis can be confirmed by analysis of MDR3 gene, coding a protein involved in physiologic translocation of phospholipids in bile. Discovery of MDR3 mutations is of particular interest, since normally associated with good effectiveness of medication by ursodesoxycholic acid. AIM: To review MDR3 mutations in humans associated with recurrent cholesterol microlithiasis and to suggest a practical approach for MDR3 gene analysis. RESULTS: 48 mutations of MDR3 gene have been reported in humans to date, from which 43 (89.5%) in the coding region, and 5 splice site mutations have been associated to cholesterol cholelithiasis. 21 (43.8%) of the 43 precited mutations are located in only 8 exons on 28, near transmembrane or nucleotide binding domains of the protein. From the 22 remaining described mutations, 9 (18.8%) are restricted to exon 14. We suggest therefore to start analysis of MDR3 gene by screening exons 6, 7, 9, 10, 12, 14, 17, 23 and 24 with an appropriate protocol in this diagnosis associated with effective treatment. In conclusion such therapeutic orientation is valuable, since recurrent cholesterolic microlithiasis occurs relatively early in life, and by the fact that recurrence of symptoms may occur despite cholecystectomy, or shock-wave therapy.

[Study on the position of genes responsible for gallstone disease in Chinese population].

OBJECTIVE: To search the susceptibility genes of gallstone disease in Chinese population. METHODS: A genome wide scan was performed in twelve families with gallstone disease using fluorescence-labeled microsatellite markers. Genehunter and Batchlink of Linkage package were used for non- parameter and parameter linkage analysis to search the linkage loci on chromosomes. RESULTS: Four loci of D3S1266, D4S406, D9S1682 and D11S902 showed suggestive evidence for linkage. nonparametric linkage analysis (NPL)-score of D4S406 and D9S1682 was 1.77 (P = 0.05) and 1.92 (P = 0.04) respectively. The corresponding logarithm of the odds ratio (LOD)-score of D3S1266, D9S1682 were 1.35 and 2.07, and showed a rise of LOD-score from 1.35 to 2.71, 2.07 to 2.40 respectively when families with later-found patients or with higher triglyceride level were analyzed alone. Transmitted disequilibrium test of D11S902 showed a P-value of 0.0027. CONCLUSIONS: Chromosome 3, 4, 9 and 11 may contain genes involved in gallstone disease in Chinese population, and chromosome 3, 9 may hide genes that are liked to gallstone disease in families with later-found patients or with higher triglyceride concentration.

Detection of cancer cells and gene expression of cytokines in the peritoneal cavity in patients with gastric cancer.

BACKGROUND: The gene expression of the cytokines interleukin-2 (IL-2) and IL-10 in peritoneal washings was examined in relation to the presence of cancer cells in the peritoneal cavity in patients with gastric cancer. METHODS: Total RNA was extracted from 50-ml peritoneal wash samples from 124 patients (gastric cancer, n = 110; controls, n = 14). Carcinoembrionic antigen (CEA) messenger RNA (mRNA) was used to identify the number of cancer cells in peritoneal wash samples by a real-time reverse transcription-polymerase chain reaction (RT-PCR) method, which method was also used to assay the IL-2 and IL-10 gene expression levels. RESULTS: In the 14 control samples, CEA mRNA was not detected, while CEA mRNA was detected in 2 of the 51 stage I gastric cancer patients. Thus, the specificity of this method for the detection of cancer cells in peritoneal wash samples was 97% (63/65). The CEA-based real-time RT-PCR method demonstrated greater prognostic impact than the traditional cytological method. IL-2 gene expression in peritoneal wash samples that were CEA mRNA-positive was suppressed compared with that in peritoneal wash samples that were CEA mRNA-negative, while IL-10 gene expression did not differ according to the CEA mRNA findings. CONCLUSION: The detection of small numbers of cancer cells in peritoneal wash samples from patients with advanced gastric cancer is a good marker for peritoneal metastatic recurrence. In the peritoneal cavity, cancer cells may escape from immune surveillance by controlling the expression of cytokines.

Mechanisms of disease: the genetic epidemiology of gallbladder stones.

Cholelithiasis is one of the most prevalent and most expensive gastroenterologic diseases. It belongs to the group of complex metabolic disorders that affect humans, and its critical pathogenic mechanisms are not well defined. As a result, primary or secondary prevention strategies are sparse, and the only effective treatment is cholecystectomy. Here we provide an update on the molecular pathogenesis of gallbladder stones, evidence supporting the hypothesis that genetic factors are key elements predisposing to gallstones, and progress in human genetic studies of cholesterol stones. Data from recent identical twin, family and linkage studies provide conclusive evidence for a strong genetic component to gallstone disease. Furthermore, epidemiologic studies in at-risk populations indicate that gallstone formation is caused by multiple environmental influences and common genetic factors and their interactions. By contrast, monogenic subtypes of cholelithiasis, such as ATP-binding-cassette transporter deficiencies, appear to be rare. The summary of human association studies illustrates that distinct common gene variants might contribute to gallstone formation in different ethnic groups. The characterization of lithogenic genes in knockout and transgenic mice and the identification of many gallstone-susceptibility loci in inbred mice provide the basis for studies of the corresponding genes in patients with gallstones. The transfer of findings from mouse genetics to the bedside might lead to new strategies for individual risk assessment and reveal novel molecular targets for prevention and medical therapies.

[The relationship between the C589T polymorphism of IL-4 gene and cholelithiasis].

OBJECTIVE: To investigate the relationship between IL-4 gene polymorphism and cholelithiasis in Chinese population. METHODS: Polymerase chain reaction combined with restriction enzyme digestion was used to detect the polymorphism of IL-4 gene in 81 cholecystolithiasis, 41 patients with biliary duct stone. RESULTS: There were no significant differences of the IL-4 gene polymorphism genotypes and alleles between 81 cholecystolithiasis patients (CC11.1%, CT34.6%, TT54.3%; C28.4.7%, T71.6%). There were significant differences of the IL-4 gene polymorphism genotypes and alleles between 41 patients with biliary duct stone (CC48.8%, CT36.6%, TT14.6%; C67.1%, T32.9%). CONCLUSIONS: The C589T polymorphism of IL-4 gene was not associated with cholecystolithiasis patients in Chinese, but was related to patients with biliary duct stone in Chinese.

Genomic determination of CR1 CD35 density polymorphism on erythrocytes of patients with gallbladder carcinoma.

AIM: To study the changes of quantitative expression, adhering activity and genomic density polymorphism of complement types in erythrocytes (CR1) of patients with gallbladder carcinoma and the related clinical significance. METHODS: Polymerase chain reaction (PCR), Hind III restriction enzyme digestion, quantitative assay of CR1 and adhering activity assay of CR1 in erythrocytes were used. RESULTS: The number and adhering activity of CR1 in patients with gallbladder carcinoma (0.738+/-0.23, 45.9+/-5.7) were significantly lower than those in chronic cholecystitis and cholecystolithiasis (1.078+/-0.21, 55.1+/-5.9) and healthy controls (1.252+/-0.31, 64.2+/-7.4) (P<0.01). The number and adhering activity of CR1 in patients with chronic cholecystitis and cholecystolithiasis (1.078+/-0.21, 55.1+/-5.9) were significantly lower than those in healthy controls (1.252+/-0.31, 64.2+/-7.4) (P<0.05). There was a positive correlation between quantitative expression and adhering activity of CR1 (r = 0.79, P<0.01). Compared with those on preoperative day (0.738+/-0.23, 45.4+/-4.9), the number and adhering activity of CR1 in patients with gallbladder carcinoma decreased greatly on the third postoperative day (0.310+/-0.25, 31.8+/-5.1) (P<0.01), and on the first postoperative week (0.480+/-0.25, 38.9+/-5.2) (P<0.01), but they were increased slightly than those on the preoperative day (P>0.05). The number and adhering activity of CR1 recovered in the second postoperative week(0.740+/-0.24, 46.8+/-5.9) (P<0.01) and increased greatly in the third postoperative week (0.858+/-0.35, 52.7+/-5.8) (P<0.01) in comparison with those on the preoperative day and in the first postoperative week. The number and adhering activity of CR1 of gallbladder carcinoma patients with infiltrating, adjacent lymphogenous and distant organ metastases were significantly lower than those of gallbladder carcinoma patients without them (P<0.01). No difference was observed between the patients with gallbladder carcinoma and healthy individuals in the spot mutation rate of CR1 density gene (chi(2) = 0.521, P>0.05). The distribution of expression was 67.8% in high expression genomic type, 24.8% in moderate expression genomic type, and 7.4% in low expression genomic type. The number and adhering activity of CR1 high expression genomic type gallbladder carcinomas (0.749+/-0.22, 42.1+/-6.2) were significantly lower than those of healthy individuals (1.240+/-0.29, 63.9+/-7.2), and were also significantly lower than those of healthy individuals (0.921+/-0.23, 54.8+/-7.1), but no difference was observed between the number and adhering activity of CR1 lower expression genomic type gallbladder carcinomas (0.582+/-0.18, 44.3+/-5.5) and those of healthy individuals (0.610+/-0.20, 45.8+/-5.7) (P>0.05). CONCLUSION: Defective expression of CR1 in gallbladder carcinoma is mostly acquired through central peripheral mechanisms. The changes in CR1 quantitative expression and adhering activity are consanguineously related to the development and metastasis in gallbladder carcinoma.

[Evidence-based prevention of cholecystolithiasis]. / Evidenzbasierte Prävention der Cholezystolithiasis.

Evidence based prevention of cholecystolithiasis. Cholesterol cholelithiasis is one of the most common and expensive gastroenterological diseases. Beside common exogenous risk factors, recent molecular genetic studies have identified genetic risk factors for both cholesterol and pigment stone formation. Examples are low phospholipid-associated cholelithiasis due to mutations of the gene encoding the hepatocanalicular phosphatidylcholine transporter, and pigment stones in association with mutations of the ileal bile salt transporter gene. Evidence-based options for primary prevention of cholecystolithiasis include physical activity, slow weight reduction, regular vitamin C supplementation, and moderate coffee consumption. The ongoing genome projects provide the basis for future epidemiological studies of human gallstone (LITH) genes, which might offer new prospects for individual risk assessment and prevention of gallstones.

Smooth muscle function and dysfunction in gallbladder disease.

The gallbladder epithelium and smooth muscle layer are exposed to concentrated biliary solutes, including cholesterol and potentially toxic hydrophobic bile salts, which are able to influence muscle contraction. Physiologically, gallbladder tone is regulated by spontaneous muscle activity, hormones, and neurotransmitters released into the muscle from intrinsic neurons and extrinsic sympathetic nerves. Methods to explore gallbladder smooth muscle function in vitro include cholecystokinin (CCK) receptor-binding studies and contractility studies. In human and animal models, studies have focused on cellular and molecular events in health and disease, and in vitro findings mirror in vivo events. The interplay between contraction and relaxation of the gallbladder muscularis leads in vivo to appropriate gallbladder emptying and refilling during fasting and postprandially. Defective smooth muscle contractility and/or relaxation are found in cholesterol stone-containing gallbladders, featuring a type of gallbladder leiomyopathy; defects of CCKA receptors and signal transduction may coexist with abnormal responses to oxidative stress and inflammatory mediators. Abnormal smooth musculature contractility, impaired gallbladder motility, and increased stasis are key factors in the pathogenesis of cholesterol gallstones.

[Correlation between gene expression of CCK-A receptor and gallbladder emptying in gallstone patients].

OBJECTIVE: To investigate the expression of CCK-A receptor and its relation with gallbladder hypomotility in patients with gallstone. METHODS: 20 patients with gallstone and 10 normal subjects were studied and gallbladder emptying function was measured by B ultrasonography. The other 8 patients without gallstone who died of accident were selected as controls for measuring mRNA expression of CCK-A receptor of gallbladder; RT-PCR was used to explore gene expression of CCK-A receptor of gallbladder. RESULTS: The gallbladder motility was significantly impaired in gallstone patients. The patients had lower mRNA expression of CCK-A receptor than control subjects (0.633 +/- 0.167 vs. 0.944 +/- 0.230, P < 0.01), and so did patients with impaired gallbladder motility then those with normal motility (0.544 +/- 0.124 vs. 0.768 +/- 0.131, P < 0.05). Furthermore, the change of expression of CCK-A receptors was markedly correlated with gallbladder emptying (r = 0.925, P < 0.01). CONCLUSIONS: mRNA expression of CCK-A receptor in gallstone patients decreases, which was related to gallbladder hypomotility. The down-regulation of gene expression of CCK-A receptor plays an important role in gallbladder hypomotility in patients with gallstone.