Gallbladder dysfunction caused by MYPT1 ablation triggers cholestasis-induced hepatic fibrosis in mice.

BACKGROUND: The incidence of gallbladder diseases is as high as 20%, but whether gallbladder diseases contribute to hepatic disorders remains unknown. METHODS: Here, we established an animal model of gallbladder dysfunction and assessed the role of a diseased gallbladder in cholestasis-induced hepatic fibrosis (CIHF). RESULTS: Mice with smooth muscle-specific deletion of Mypt1, the gene encoding the main regulatory subunit of myosin light chain phosphatase (myosin phosphatase target subunit 1 [MYPT1]), had apparent dysfunction of gallbladder motility. This dysfunction was evidenced by abnormal contractile responses, namely, inhibited cholecystokinin 8-mediated contraction and nitric oxide-resistant relaxation. As a consequence, the gallbladder displayed impaired bile filling and biliary tract dilation comparable to the alterations in CIHF. Interestingly, the mutant animals also displayed CIHF features, including necrotic loci by the age of 1 month and subsequently exhibited progressive fibrosis and hyperplastic/dilated bile ducts. This pathological progression was similar to the phenotypes of the animal model with bile duct ligation and patients with CIHF. The characteristic biomarker of CIHF, serum alkaline phosphatase activity, was also elevated in the mice. Moreover, we observed that the myosin phosphatase target subunit 1 protein level was able to be regulated by several reagents, including lipopolysaccharide, exemplifying the risk factors for gallbladder dysfunction and hence CIHF. CONCLUSIONS: We propose that gallbladder dysfunction caused by myosin phosphatase target subunit 1 ablation is sufficient to induce CIHF in mice, resulting in impairment of the bile transport system.

First multivisceral transplantation in Mitchell-Riley/Martinez-Frias syndrome.

BACKGROUND: MRS/MFS is a rare multisystem disorder with a poor prognosis. The high mortality rate of this syndrome is related to the severity of the associated gastrointestinal, pancreatic, and hepatobiliary conditions, as most of them are not amenable to conventional medical and surgical treatments. METHODS: We report the case of a Romani girl with all the key clinical features of MRS/MFS, and a review of cases reported in the literature. Our patient is a newborn from consanguineous parents who presented duodenal atresia, hypoplastic pancreas, gallbladder agenesis, and neonatal diabetes. Given the clinical suspicion of MRS/MFS, a genetic analysis was performed which revealed the presence of a homozygous variant in the RFX6 gene. During the course of the disease, the patient presented intractable secretory diarrhea and severe intestinal failure. RESULTS: At 2 years of age, she underwent MVT of the stomach, duodenum, small intestine, colon, liver, and pancreas. There were no surgical complications. Histologic evaluation of the small bowel showed extensive patches of gastric heterotopia. After more than 10 years of follow-up, she had presented with normal gastrointestinal, hepatic, and pancreatic function. She has one of the longest survival periods in the literature. CONCLUSIONS: Our experience suggests that multivisceral transplantation may be a promising option in select cases of MRS/MFS.

Mitchell-Riley syndrome iPSCs exhibit reduced pancreatic endoderm differentiation due to a mutation in RFX6.

Mitchell-Riley syndrome (MRS) is caused by recessive mutations in the regulatory factor X6 gene (RFX6) and is characterised by pancreatic hypoplasia and neonatal diabetes. To determine why individuals with MRS specifically lack pancreatic endocrine cells, we micro-CT imaged a 12-week-old foetus homozygous for the nonsense mutation RFX6 c.1129C>T, which revealed loss of the pancreas body and tail. From this foetus, we derived iPSCs and show that differentiation of these cells in vitro proceeds normally until generation of pancreatic endoderm, which is significantly reduced. We additionally generated an RFX6HA reporter allele by gene targeting in wild-type H9 cells to precisely define RFX6 expression and in parallel performed in situ hybridisation for RFX6 in the dorsal pancreatic bud of a Carnegie stage 14 human embryo. Both in vitro and in vivo, we find that RFX6 specifically labels a subset of PDX1-expressing pancreatic endoderm. In summary, RFX6 is essential for efficient differentiation of pancreatic endoderm, and its absence in individuals with MRS specifically impairs formation of endocrine cells of the pancreas head and tail.

ABCB4 disease: Many faces of one gene deficiency.

ATP-binding cassette (ABC) subfamily B member 4 (ABCB4), also known as multidrug resistance protein 3 (MDR3), encoded by ABCB4, is involved in biliary phospholipid secretion, protecting hepatobiliary system from deleterious detergent and lithogenic properties of the bile. ABCB4 mutations altering canalicular ABCB4 protein function and expression may have variable clinical presentation and predispose to several human liver diseases. Well-established phenotypes of ABCB4 deficit are: progressive familial intrahepatic cholestasis type 3, gallbladder disease 1 (syn. low phospholipid associated cholelithiasis syndrome), high ɣ-glutamyl transferase intrahepatic cholestasis of pregnancy, chronic cholangiopathy, and adult biliary fibrosis/cirrhosis. Moreover, ABCB4 aberrations may be involved in some cases of drug induced cholestasis, transient neonatal cholestasis, and parenteral nutrition-associated liver disease. Recently, genome-wide association studies have documented occurrence of malignant tumours, predominantly hepatobiliary malignancies, in patients with ABCB4/MDR3 deficit. The patient's age at the time of the first presentation of cholestatic disease, as well as the severity of liver disorder and response to treatment are related to the ABCB4 allelic status. Mutational analysis of ABCB4 in patients and their families should be considered in all individuals with cholestasis of unknown aetiology, regardless of age and/or time of onset of the first symptoms.

Acute Recurrent and Chronic Pancreatitis as Initial Manifestations of Cystic Fibrosis and Cystic Fibrosis Transmembrane Conductance Regulator-Related Disorders.

OBJECTIVES: Recurrent pancreatitis is considered a rare manifestation of cystic fibrosis transmembrane conductance regulator (CFTR) dysfunction; this case series highlights that pancreatitis can be a presenting symptoms of cystic fibrosis (CF) or a CFTR-related disorder (CFTR-RD). METHODS: Retrospective review of patients younger than 30 years diagnosed as having acute recurrent pancreatitis (ARP) or chronic pancreatitis (CP) and subsequently diagnosed as having CF or CFTR-RD. RESULTS: Among 18 patients, median time from diagnosis of ARP/CP to diagnosis of CF was 0.4 years (range, 0-33 years). Eight were classified as having CF by elevated sweat chloride testing (SCT). Five had intermediate SCT (30-59 mmol/L) with 2 pathogenic mutations. Five had CFTR-RD with intermediate SCT and 0 to 1 pathogenic mutations. Eight patients (44%) had exocrine pancreatic insufficiency, and pancreatic fluid collections were more common in this group. Based on the CFTR mutation, 6 patients were eligible for CFTR potentiator therapy, although none received it during the study period. Nine of the 18 had ≥1 other likely CF manifestations, including sinusitis (33%), nasal polyps (11%), pneumonia (22%), and gallbladder disease (22%). CONCLUSIONS: Cystic fibrosis or CFTR-RD can present as ARP/CP. Complete diagnostic testing for CFTR-RD in patients with ARP/CP will broaden treatment options and help to identify comorbid illness.

Mutational and non mutational adaptation of Salmonella enterica to the gall bladder.

During systemic infection of susceptible hosts, Salmonella enterica colonizes the gall bladder, which contains lethal concentrations of bile salts. Recovery of Salmonella cells from the gall bladder of infected mice yields two types of isolates: (i) bile-resistant mutants; (ii) isolates that survive lethal selection without mutation. Bile-resistant mutants are recovered at frequencies high enough to suggest that increased mutation rates may occur in the gall bladder, thus providing a tentative example of stress-induced mutation in a natural environment. However, most bile-resistant mutants characterized in this study show defects in traits that are relevant for Salmonella colonization of the animal host. Mutation may thus permit short-term adaptation to the gall bladder at the expense of losing fitness for transmission to new hosts. In contrast, non mutational adaptation may have evolved as a fitness-preserving strategy. Failure of RpoS- mutants to colonize the gall bladder supports the involvement of the general stress response in non mutational adaptation.

Gall bladder mucoceles in Border terriers.

BACKGROUND: Gall bladder mucoceles (GBM) are a leading cause of biliary disease in dogs with several breeds, including the Shetland Sheepdog, American Cocker Spaniel, Chihuahua, Pomeranian, and Miniature Schnauzer apparently predisposed. OBJECTIVE: To determine risk factors, clinical features, and response to treatment of GBM in Border terriers (BT). ANIMALS: Medical records of 99 dogs (including 51 BT) with an ultrasonographic (±histopathologic) diagnosis of GBM from three referral centers in the United Kingdom were collected. A control group of 87 similar-aged BT with no ultrasonographic evidence of gall bladder disease was selected for comparison. METHOD: Retrospective case-control study. Odds ratios were calculated to establish breed predisposition. Signalment, presence of endocrine disease, clinicopathologic results, and outcome were compared between the BT, other breeds, and control BTs. RESULTS: The odds of identifying a GBM in a BT in this hospital population was 85 times that of all other breeds (95% confidence interval 56.9-126.8). BT had similar clinical signs and clinicopathologic changes to other breeds with GBM. There was no evidence that endocrinopathies were associated with GBM in BT. CLINICAL SIGNIFICANCE: A robust breed predisposition to GBM is established for the BT.

Prognostic significance of promoter DNA hypermethylation of the cysteine dioxygenase 1 (CDO1) gene in primary gallbladder cancer and gallbladder disease.

BACKGROUND: Aberrant promoter DNA methylation of the cysteine dioxygenase 1 (CDO1) gene is found in various human cancers and is associated with clinical outcome. In this study, we assessed for the first time the clinicopathological significance of CDO1 methylation in primary gallbladder cancer (GBC) in comparison with non-malignant gallbladder disease. METHODS: CDO1 DNA methylation was quantified using quantitative TaqMan methylation specific PCR (Q-MSP) in 99 primary GBC patients together with the 78 corresponding non-tumor tissues and 26 benign gallbladder disease (including 7 patients with xanthogranulomatous cholecystitis) who underwent surgical resection between 1986 and 2014. RESULTS: The average CDO1 TaqMeth value of primary GBCs was 23.5±26. These values were significantly higher than those of corresponding non-tumor tissues (average 8±13, p < .0001) and diseased gallbladder tissues from patients with benign gallbladder diseases (average 0.98±1.6, p < .0001). CDO1 hypermethylation is also found in xanthogranulomatous cholecystitis. Using a cut-off value of 17.7, GBC cases with CDO1 hypermethylation (n = 47) showed significantly poorer prognosis than those with CDO1 hypomethylation (n = 52) (p = 0.0023). Multivariate Cox proportional hazards analysis identified that CDO1 hypermethylation was an independent prognostic factor. Notably, CDO1 hypermethylation showed prognostic relevance, especially in stage II GBC, in which it is highly anticipated to work as a predictive marker for candidates of adjuvant therapy. CONCLUSIONS: Promoter NA methylation of CDO1 was demonstrated for the first time to be a cancer-associated methylation in primary GBC, and it has the potential to be a prognostic biomarker of GBC for high-risk patients with stage II GBC.

Two novel RFX6 variants in siblings with Mitchell-Riley syndrome with later diabetes onset and heterotopic gastric mucosa.

Mitchell-Riley syndrome, an autosomal recessive disorder caused by mutations in the RFX6 gene, is defined as a combination of neonatal diabetes mellitus and serious congenital gastrointestinal defects. We describe Mitchell-Riley syndrome in two sisters with two novel compound heterozygous variants in the RFX6 gene: c.1154G > A, p.(Arg385Gln), and c.1316_1319delTCTA, p.(Ile439Thrfs*13). Both sisters present milder forms of the syndrome, likely due to possible residual activity of the p.Arg385Gln variant, which is localized in a dimerization domain of the RFX6 transcription factor. We propose that the prognosis is dependent on patient RFX6 genotype and possible residual activity of RFX6 transcription factor. Both sisters had atypical later onset of diabetes, at 2 years and 10 months and 2 years and 7 months, respectively. This supports the need of extending the definition of diabetes in Mitchell-Riley syndrome from neonatal to childhood onset and regular glyceamia check in patients with gastrointestinal tract malformations typical for Mitchell-Riley syndrome. The clinical course in both sisters improved significantly after surgical removal of parts of the small intestine with heterotopic gastric mucosa. We suggest that gastric mucosa heterotopy is an important actionable part of Mitchell-Riley syndrome and could have been responsible for the malabsorption, failure to thrive and severe anemia present in previously reported patients with Mitchell-Riley syndrome.

A Newly-Discovered Mutation in the RFX6 Gene of the Rare Mitchell-Riley Syndrome.

Mitchell-Riley syndrome is a genetic disorder characterized by neonatal diabetes, pancreatic hypoplasia, intestinal atresia and/or malrotation, biliary atresia, and gallbladder aplasia or hypoplasia. It was considered a variant of the Martinez-Frias syndrome with similar phenotypic characteristics, except for neonatal diabetes and tracheoesophageal fistula. However, the genetic mutation in (regulatory factor X on chromosome 6) RFX6 was only detected in babies who had diabetes, making it different from the previously known mutations for the disease. This is the first reported case of a classical Mitchell-Riley syndrome in the Arab peninsula along with additional features and novel mutations in the RFX6 gene.

Lipids, obesity and gallbladder disease in women: insights from genetic studies using the cardiovascular gene-centric 50K SNP array.

Gallbladder disease (GBD) has an overall prevalence of 10-40% depending on factors such as age, gender, population, obesity and diabetes, and represents a major economic burden. Although gallstones are composed of cholesterol by-products and are associated with obesity, presumed causal pathways remain unproven, although BMI reduction is typically recommended. We performed genetic studies to discover candidate genes and define pathways involved in GBD. We genotyped 15,241 women of European ancestry from three cohorts, including 3216 with GBD, using the Human cardiovascular disease (HumanCVD) BeadChip containing up to ~ 53,000 single-nucleotide polymorphisms (SNPs). Effect sizes with P-values for development of GBD were generated. We identify two new loci associated with GBD, GCKR rs1260326:T>C (P = 5.88 × 10(-7), ß = -0.146) and TTC39B rs686030:C>A (P = 6.95 x 10(-7), ß = 0.271) and detect four independent SNP effects in ABCG8 rs4953023:G>A (P=7.41 × 10(-47), ß = 0.734), ABCG8 rs4299376:G(>)T (P = 2.40 × 10(-18), ß = 0.278), ABCG5 rs6544718:T>C (P = 2.08 × 10(-14), ß = 0.044) and ABCG5 rs6720173:G>C (P = 3.81 × 10(-12), ß(=)0.262) in conditional analyses taking genotypes of rs4953023:G>A as a covariate. We also delineate the risk effects among many genotypes known to influence lipids. These data, from the largest GBD genetic study to date, show that specific, mainly hepatocyte-centred, components of lipid metabolism are important to GBD risk in women. We discuss the potential pharmaceutical implications of our findings.

Biallelic RFX6 mutations can cause childhood as well as neonatal onset diabetes mellitus.

Neonatal diabetes is a highly genetically heterogeneous disorder. There are over 20 distinct syndromic and non-syndromic forms, including dominant, recessive and X-linked subtypes. Biallelic truncating or mis-sense mutations in the DNA-binding domain of the RFX6 transcription factor cause an autosomal recessive, syndromic form of neonatal diabetes previously described as Mitchell-Riley syndrome. In all, eight cases have been reported, with the age at onset of diabetes in the first 2 weeks of life. Here we report two individuals born to double first cousins in whom intestinal atresias consistent with a diagnosis of Mitchell-Riley syndrome were diagnosed at birth, but in whom diabetes did not present until the ages of 3 and 6 years. Novel compound heterozygous RFX6 nonsense mutations (p.Arg726X/p.Arg866X) were identified at the 3' end of the gene. The later onset of diabetes in these patients may be due to incomplete inactivation of RFX6. Genetic testing for RFX6 mutations should be considered in patients presenting with intestinal atresias in the absence of neonatal diabetes.

Prognostic relevance of human telomerase reverse transcriptase (hTERT) expression in patients with gall bladder disease and carcinoma.

BACKGROUND: Gallbladder carcinoma (GBC) has been stated as an Indian disease, with the highest number of cases being reported from certain districts of northeast India, which has an ethnically distinct population. Unfortunately there are no scientific reports on the underlying molecular mechanisms associated with the pathogenesis of the disease from this region. AIM: The present study evaluated the role of differential expression of human telomerase reverse transcriptase (hTERT) in the development of gall bladder anomalies. MATERIALS AND METHODS: Blood and tissue samples were collected from patients undergoing routine surgical resection for clinically proven cases of gallbladder disease {cholelithiasis (CL, n=50), cholecystitis (CS, n=40) and GBC (n=30) along with adjacent histopathologically proved non-neoplastic controls (n=15)} with informed consent. Whole blood was also collected from age and sex matched healthy controls (n=25) for comparative analysis. Differential hTERT mRNA expression was evaluated by semi-quantitative rt-PCR and real-time PCR based analysis using ß-actin as an internal control. Evaluation of differential hTERT protein expression was studied by Western blot analysis and immunoflourescence. Statistical analysis for differential expression and co-relation was performed by SPSSv13.0 software. RESULTS: Gallbladder anomalies were mostly prevalent in females. The hTERT mRNA and protein expression increased gradiently from normal

Clinical and genetic complexity of Mitchell-Riley/Martinez-Frias syndrome.

Mitchell-Riley syndrome/Martinez-Frias syndrome (MRS/MFS) is a rare, autosomal recessive disorder with multisystem involvement and poor prognosis. Most reported cases have been associated with homozygous or compound heterozygous mutations in the RFX6 gene, a transcriptional regulatory factor for pancreatic morphogenesis. Given the limited number of reported cases, the syndrome may be under-recognized. When the particular phenotype of MFS includes a mutation on the RFX6 gene and neonatal diabetes, it has been called Mitchell-Riley syndrome. Because of this, we propose that MFS/MRS is a symptom continuum or an RFX6 malformation complex. We report an infant with all of the key clinical features of MRS/MFS without a definable mutation in RFX6 gene, supporting the consideration of these features as a symptom complex, and raising the question of genetic heterogeneity.

Expression of survivin mRNA in gallbladder cancer: a diagnostic and prognostic marker?

Survivin, an inhibitor of apoptosis, has been shown to be expressed in various malignancies. However, its role in gallbladder cancer (GBC) has not been evaluated yet. We investigated its expression in peripheral blood of patients with gallbladder diseases (gallstone disease (GSD), n = 30; GBC, n = 39) and compared with healthy controls (n = 25). Survivin expression was correlated with clinicopathological parameters, diagnosis, and prognosis of patients with GBC. Expression of survivin messenger RNA (mRNA) in blood was evaluated by real-time PCR. Significantly higher (P < 0.0001) expression of survivin mRNA was observed in GBC (2.2-fold) and GSD (1.52-fold) as compared to control. In GBC, increased survivin expression was significantly associated with higher tumor stage (stage III vs. stage II; P < 0.0001) and tumor differentiation (poor and moderate vs. well differentiated; P < 0.0001). No significant correlation was observed with any of the other clinicopathological parameters (age, gender, and presence or absence of gallstones) studied. Cutoff value of survivin mRNA relative quantification (RQ) was 1.08, with a sensitivity of 98.55 % and specificity of 100 % for the diseased group (GSD or GBC). RQ value of 1.71 differentiated GBC from GSD with a sensitivity of 89.74 % and specificity of 100 %. Increased expression of survivin was associated with a shorter median overall survival (12 vs. 18 months) in GBC patients. Differential expression of survivin in GBC suggests its possible role and association with poor prognosis. Expression of survivin in peripheral blood could be useful both in the diagnosis and prognosis of GBC.

Comparison of the gene expression profiles between gallstones and gallbladder polyps.

BACKGROUND: Gallstones and gallbladder polyps (GPs) are two major types of gallbladder diseases that share multiple common symptoms. However, their pathological mechanism remains largely unknown. The aim of our study is to identify gallstones and GPs related-genes and gain an insight into the underlying genetic basis of these diseases. METHODS: We enrolled 7 patients with gallstones and 2 patients with GP for RNA-Seq and we conducted functional enrichment analysis and protein-protein interaction (PPI) networks analysis for identified differentially expressed genes (DEGs). RESULTS: RNA-Seq produced 41.7 million in gallstones and 32.1 million pairs in GPs. A total of 147 DEGs was identified between gallstones and GPs. We found GO terms for molecular functions significantly enriched in antigen binding (GO:0003823, P=5.9E-11), while for biological processes, the enriched GO terms were immune response (GO:0006955, P=2.6E-15), and for cellular component, the enriched GO terms were extracellular region (GO:0005576, P=2.7E-15). To further evaluate the biological significance for the DEGs, we also performed the KEGG pathway enrichment analysis. The most significant pathway in our KEGG analysis was Cytokine-cytokine receptor interaction (P=7.5E-06). PPI network analysis indicated that the significant hub proteins containing S100A9 (S100 calcium binding protein A9, Degree=94) and CR2 (complement component receptor 2, Degree=8). CONCLUSION: This present study suggests some promising genes and may provide a clue to the role of these genes playing in the development of gallstones and GPs.

[Cholelithiasis and cholesterosis of a gallbladder: a comparison of pheno-genetypic characteristics of patients].

A study was and comparison was carried out of the phenotypical and genotypical features in 115 patients with cholelythiasis and 97 patients with cholesterosis of the gallbladder. The received data proves that cholelythiasis is characterized by the domination of (prevalence) of type O I blood type, decrease of blood types B III and AB IV in comparison to the control group and to the group with cholesterosis of the gallbladder (p < 0.05), increase of the frequency of gene O decrease of frequency of gene B, decrease of heterozygosis. Patients with cholesterosis of the gallbladder are characterized by the increase of frequency of gene A, decrease of ratio of patients with blood type B III and increase of patients with AB IV blood type (p < 0.05). The received data (results) show the presence of different and multidirectional phenotypical and genotypical characteristics in patients with cholelythiasis and cholesterosis of the gallbladder, and therefore differ genotypically.

Inflammatory fibroid polyp of the gallbladder bearing a platelet-derived growth factor receptor alpha mutation.

The inflammatory fibroid polyp (IFP) is a benign lesion occurring in the digestive tract, mostly in the stomach and small bowel, composed of fibrovascular tissue infiltrated by inflammatory cells including eosinophils and mastocytes. Its pathogenesis has been controversial (reactive versus neoplastic). The recent finding of mutations in platelet-derived growth factor receptor α (PDGFRA) in most gastric and small intestinal IFPs supported their neoplastic etiology, moreover helping in their differential diagnosis. In the only gallbladder IFP reported so far, the diagnosis was based on morphologic and immunohistochemical grounds, which in current standards would probably be considered not fully conclusive. Conversely, the gallbladder IFP we report shows typical pathologic features supported by a PDGFRA mutation, similar to its usual gastric and small intestinal counterparts, constituting the first report of an unequivocal IFP at gallbladder level. Thus, IFPs must be considered in the differential diagnosis of gallbladder mesenchymal masses, and genetic analysis of PDGFRA is a helpful tool for this purpose.

Contrast-enhanced ultrasound versus conventional ultrasound in the diagnosis of polypoid lesion of gallbladder: a multi-center study of dynamic microvascularization.

OBJECTIVE: To assess the value of contrast-enhanced ultrasound (CEUS) in the diagnosis of polypoid lesions of gallbladder (PLGs). METHODS: CEUS was performed to 116 patients (mean age, 49.6 years; range, 21-80 years) with PLGs from 8 university hospitals. 9 cases of biliary sludge were proven by surgery and the remaining 107 cases were confirmed by histopathological examination. The confidence level, diagnostic performance, inter-observer agreement of two independent readers with different experience was assessed. The readers were blind to the imaging and clinical results of the patients. RESULTS: There were significant differences between benign and malignant PLGs in patient age, gender, lesion size, echogenicity, stalk, time-to-peak, vascularity on CEUS, enhancement pattern, and wall destruction. The confidence levels increased significantly and the interobserver agreement increased from 0.425 to 0.601 after CEUS. The sensitivity increased from 22.2 to 77.8% after CEUS in the staff radiologist, and from 22.2 to 66.7% in the resident radiologist. The correctly characterized lesions were 64.7% before versus 87.1% after CEUS (P=0.125) for the staff radiologist, and 57.8% versus 70.7% for the resident radiologist (P=0.007). No significance was found in the subgroup of lesions≤1.0 cm before and after CEUS for the two radiologists. CONCLUSIONS: CEUS using convex multifrequency probes could detect the dynamic microvascularization of PLGs greater than 1.0 cm and facilitate the differentiation between benign and malignant tumors.