Bile acids regulate SF-1 to alter cholesterol balance in adrenocortical cells via S1PR2.

Glucocorticoid synthesis typically occurs in adrenal cortex and is influenced by cholesterol balance, since cholesterol is the sole precursor of steroids. Bile acids as the signaling molecules, have been shown to promote steroidogenesis in steroidogenic cells. However, whether bile acids directly regulate cholesterol balance remains elusive. In this study, we prepared cholestatic mouse models and cultured human adrenocortical cells (H295R) treated with taurochenodeoxycholic acid (TCDCA) to determine transcription levels of cholesterol metabolism associated genes and cholesterol concentrations in adrenocortical cells. Results showed that common bile duct ligation (CBDL) and chenodeoxycholic acid (CDCA) feeding elevated the mRNA levels of Abca1, Cyp51, Hmgcr, Srb1, and Mc2r in adrenals of mice. Meanwhile, the concentrations of total cholesterol and cholesteryl ester in adrenals of CBDL and CDCA-fed mice were dramatically lowered. The total and phosphorylation levels of HSL in adrenal glands of CBDL mice were also enhanced. Similarly, TCDCA treatment in H295R cells decreased intracellular concentrations of total cholesterol and cholesteryl ester and increased transcription levels of SRB1, MC2R, and HSL as well. Inhibition of bile acids' receptor sphingosine 1-phosphate receptor 2 (S1PR2), extracellular signal-regulated kinase (ERK) phosphorylation, and steroidogenic factor 1 (SF-1) respectively successfully abolished effect of TCDCA on H295R cells. SF-1s was found to be phosphorylated at Thr75 in TCDCA-treated H295R cells. While a mild increase of intracellular cAMP concentration was detected upon TCDCA treatment, inhibition of PKA activity with Rp-Isomer in H295R cells failed to decrease the expression of SF-1 and its target genes. Our findings suggest that conjugated bile acids affect cholesterol balance through regulation of SF-1 in adrenocortical cells so as to provide an adequate cholesterol supply for glucocorticoid synthesis, which improves and enriches our understanding of the mechanism whereby bile acids regulate cholesterol balance to affect adrenal function.

A combined computational and functional approach identifies IGF2BP2 as a driver of chemoresistance in a wide array of pre-clinical models of colorectal cancer.

AIM: Chemoresistance is a major cause of treatment failure in colorectal cancer (CRC) therapy. In this study, the impact of the IGF2BP family of RNA-binding proteins on CRC chemoresistance was investigated using in silico, in vitro, and in vivo approaches. METHODS: Gene expression data from a well-characterized cohort and publicly available cross-linking immunoprecipitation sequencing (CLIP-Seq) data were collected. Resistance to chemotherapeutics was assessed in patient-derived xenografts (PDXs) and patient-derived organoids (PDOs). Functional studies were performed in 2D and 3D cell culture models, including proliferation, spheroid growth, and mitochondrial respiration analyses. RESULTS: We identified IGF2BP2 as the most abundant IGF2BP in primary and metastastatic CRC, correlating with tumor stage in patient samples and tumor growth in PDXs. IGF2BP2 expression in primary tumor tissue was significantly associated with resistance to selumetinib, gefitinib, and regorafenib in PDOs and to 5-fluorouracil and oxaliplatin in PDX in vivo. IGF2BP2 knockout (KO) HCT116 cells were more susceptible to regorafenib in 2D and to oxaliplatin, selumitinib, and nintedanib in 3D cell culture. Further, a bioinformatic analysis using CLIP data suggested stabilization of target transcripts in primary and metastatic tumors. Measurement of oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) revealed a decreased basal OCR and an increase in glycolytic ATP production rate in IGF2BP2 KO. In addition, real-time reverse transcriptase polymerase chain reaction (qPCR) analysis confirmed decreased expression of genes of the respiratory chain complex I, complex IV, and the outer mitochondrial membrane in IGF2BP2 KO cells. CONCLUSIONS: IGF2BP2 correlates with CRC tumor growth in vivo and promotes chemoresistance by altering mitochondrial respiratory chain metabolism. As a druggable target, IGF2BP2 could be used in future CRC therapy to overcome CRC chemoresistance.

Drug Therapies for Chronic Cholestatic Liver Diseases.

Though ursodeoxycholic acid (UDCA) remains the baseline treatment for most cholestatic liver diseases, UDCA treatment leaves approximately one-third of patients with primary biliary cholangitis (PBC) and all patients with primary sclerosing cholangitis (PSC) at risk for disease progression. New anticholestatic agents, including nuclear receptor agonists, choleretics, and bile acid synthesis suppressors, will likely increase response rates to therapy in PBC and PSC. Strategies that target early immune-mediated injury have so far been disappointing, hampered by the lack of biomarkers to detect early disease states, which then could profit from immunomodulatory therapy. Future concepts need to personalize treatments according to disease stage, progression, and phase, and to combine multiple drugs to target different pathogenic pathways.

Fungal translocation measured by serum 1,3-ß-D-glucan correlates with severity and outcome of liver cirrhosis-A pilot study.

BACKGROUND & AIMS: On a global scale, liver cirrhosis is attributable to ~1 million deaths per year. This systemic disease comes along with diverse sequelae, including microbiota alterations, increased gut permeability and translocation of microbial components into the systemic circulation. Alongside the extensively studied influence of bacterial translocation and its host-pathogen interactions, far less is known about the role and impact of fungal components once having crossed the intestinal barrier. METHODS: Including 70 patients with different aetiologies of liver cirrhosis, we investigated the relationship between fungal translocation, measured by 1,3-ß-D-glucan (BDG), and biomarkers of gut integrity, inflammation and severity/outcome of liver disease. RESULTS: Patients with cirrhosis Child-Pugh class (CPC)-B were more likely to have positive serum BDG (aOR 5.4, 95% CI 1.2-25.2) compared to patients with cirrhosis CPC-A. BDG showed a moderate positive correlation with several markers of inflammation (sCD206, sCD163, Interleukin 8, interferon-gamma-induced protein). Mortality differed significantly between patients with positive versus negative BDG (log-rank test, p = 0.015). The multivariable Cox regression model yielded an aHR of 6.8 (95% CI 1.8-26.3). DISCUSSION: We observed trends for increased fungal translocation depending on the severity of liver cirrhosis, an association of BDG with an inflammatory environment and the adverse effects of BDG on disease outcome. In order to gain more in-depth knowledge about (fungal-)dysbiosis and its detrimental consequences in the setting of liver cirrhosis, these trends need to be studied in more detail including prospective sequential testing in larger cohorts together with mycobiome analyses. This will further elucidate complex host-pathogen interactions and potentially introduce points of application for therapeutic interventions.

A novel score predicts mortality after transjugular intrahepatic portosystemic shunt: MOTS - Modified TIPS Score.

BACKGROUND AND AIMS: The high risk for severe shunting-related post-interventional complications demands a stringent selection of candidates for transjugular intrahepatic portosystemic shunt (TIPS). We aimed to develop a simple and reliable tool to accurately predict early post-TIPS mortality. METHODS: 144 cases of TIPS implantation were retrospectively analysed. Using univariate and multivariate Cox regression analysis of factors predicting mortality within 90 days after TIPS, a score integrating urea, international normalized ratio (INR) and bilirubin was developed. The Modified TIPS-Score (MOTS) ranges from 0 to 3 points: INR >1.6, urea >71 mg/dl and bilirubin >2.2 mg/dl account for one point each. Additionally, MOTS was tested in an external validation cohort (n = 187) and its performance was compared to existing models. RESULTS: Modified TIPS-Score achieved a significant prognostic discrimination reflected by 90-day mortality of 8% in patients with MOTS 0-1 and 60% in patients with MOTS 2-3 (p < .001). Predictive performance (area under the curve) of MOTS was accurate (c = 0.845 [0.73-0.96], p < .001), also in patients with renal insufficiency (c = 0.830 [0.64-1.00], p = .02) and in patients with refractory ascites (c = 0.949 [0.88-1.00], p < .001), which are subgroups with particular room for improvement of post-TIPS mortality prediction. The results were reproducible in the validation cohort. CONCLUSIONS: Modified TIPS-Score is a novel, practicable tool to predict post-TIPS mortality, that can significantly simplify clinical decision making. Its practical applicability should be further investigated.

Liver Fibrosis-4 index indicates atrial fibrillation in acute ischemic stroke.

BACKGROUND: Non-alcoholic fatty liver disease and particularly liver fibrosis are related to cardiovascular disease and may indicate an increased risk for atrial fibrillation (AF), but this association has not yet been systematically investigated in a cohort of ischemic stroke patients. METHODS: We analyzed data from a prospective single-center study enrolling all consecutive ischemic stroke patients admitted to our stroke unit over a 1-year period. All patients received a thorough etiological workup. For evaluation of liver fibrosis, we determined the Fibrosis-4 (FIB-4) index, a well-established noninvasive liver fibrosis test. Laboratory results were analyzed from a uniform blood sample taken at stroke unit admission. RESULTS: Of 414 included patients (mean age 70.2 years, 57.7% male), FIB-4 indicated advanced liver fibrosis in 92 (22.2%). AF as the underlying stroke mechanism was present in 28.0% (large vessel disease: 25.6%, small vessel disease: 11.4%, cryptogenic: 29.2%). Patients with FIB-4 ≥ 2.67 had higher rates of AF (53.3% vs. 20.8%, p < 0.001), and this association remained significant after correction for established AF risk factors (odds ratio 2.53, 95% confidence interval 1.44-4.46, p = 0.001). FIB-4 was further associated with worse functional outcome 3 months (p < 0.001) and higher mortality 4 years post-stroke (p < 0.02), but these relationships were no longer present after correction for age and initial stroke severity. Moreover, FIB-4 was not associated with long-term recurrent vascular events. CONCLUSIONS: Liver fibrosis assessed by the FIB-4 index is independently associated with AF in acute ischemic stroke patients. Further studies should evaluate whether adding the FIB-4 index to AF risk scores increases their precision.

Downregulation of TGR5 (GPBAR1) in biliary epithelial cells contributes to the pathogenesis of sclerosing cholangitis.

BACKGROUND & AIMS: Primary sclerosing cholangitis (PSC) is characterized by chronic inflammation and progressive fibrosis of the biliary tree. The bile acid receptor TGR5 (GPBAR1) is found on biliary epithelial cells (BECs), where it promotes secretion, proliferation and tight junction integrity. Thus, we speculated that changes in TGR5-expression in BECs may contribute to PSC pathogenesis. METHODS: TGR5-expression and -localization were analyzed in PSC livers and liver tissue, isolated bile ducts and BECs from Abcb4-/-, Abcb4-/-/Tgr5Tg and ursodeoxycholic acid (UDCA)- or 24-norursodeoxycholic acid (norUDCA)-fed Abcb4-/- mice. The effects of IL8/IL8 homologues on TGR5 mRNA and protein levels were studied. BEC gene expression was analyzed by single-cell transcriptomics (scRNA-seq) from distinct mouse models. RESULTS: TGR5 mRNA expression and immunofluorescence staining intensity were reduced in BECs of PSC and Abcb4-/- livers, in Abcb4-/- extrahepatic bile ducts, but not in intrahepatic macrophages. No changes in TGR5 BEC fluorescence intensity were detected in liver tissue of other liver diseases, including primary biliary cholangitis. Incubation of BECs with IL8/IL8 homologues, but not with other cytokines, reduced TGR5 mRNA and protein levels. BECs from Abcb4-/- mice had lower levels of phosphorylated Erk and higher expression levels of Icam1, Vcam1 and Tgfß2. Overexpression of Tgr5 abolished the activated inflammatory phenotype characteristic of Abcb4-/- BECs. NorUDCA-feeding restored TGR5-expression levels in BECs in Abcb4-/- livers. CONCLUSIONS: Reduced TGR5 levels in BECs from patients with PSC and Abcb4-/- mice promote development of a reactive BEC phenotype, aggravate biliary injury and thus contribute to the pathogenesis of sclerosing cholangitis. Restoration of biliary TGR5-expression levels represents a previously unknown mechanism of action of norUDCA. LAY SUMMARY: Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease-associated with progressive inflammation of the bile duct, leading to fibrosis and end-stage liver disease. Bile acid (BA) toxicity may contribute to the development and disease progression of PSC. TGR5 is a membrane-bound receptor for BAs, which is found on bile ducts and protects bile ducts from BA toxicity. In this study, we show that TGR5 levels were reduced in bile ducts from PSC livers and in bile ducts from a genetic mouse model of PSC. Our investigations indicate that lower levels of TGR5 in bile ducts may contribute to PSC development and progression. Furthermore, treatment with norUDCA, a drug currently being tested in a phase III trial for PSC, restored TGR5 levels in biliary epithelial cells.

Hypercortisolism in patients with cholestasis is associated with disease severity.

BACKGROUND: Cholestasis might lead to an impairment of adrenal function as suggested by in vitro and in vivo data as well as by clinical findings. Bile acid and adrenal steroid metabolism not only share the receptors farnesoid X receptor (FXR) and the G protein-coupled bile acid receptor 1 (TGR5), but supraphysiological bile acid levels were found to stimulate steroidogenesis independent of FXR and TGR5. Our previous experimental findings revealed that mice fed bile acids or subjected to common bile duct ligation develop hypercortisolemia. We thus aimed to assess adrenal gland function in patients with cholestasis. METHODS: Adrenal gland function was assessed in 36 patients with cholestasis and in 32 patients without cholestasis by measuring total serum cortisol, adrenocorticotropic hormone (ACTH), as well as the increase of cortisol 20 and 30 min after administration of 1 µg of ACTH. Bile acid levels and bile acid pool composition were determined by high-resolution mass spectrometry. RESULTS: Patients with cholestasis per definition had markedly elevated levels of alkaline phosphatase (AP), bilirubin and serum bile acids. Baseline cortisol and maximum cortisol after ACTH stimulation were significantly higher in patients with cholestasis compared to controls. Increase of cortisol after ACTH stimulation and ACTH did not differ. In the cholestasis group, baseline cortisol correlated with bilirubin but not with AP, total serum bile acids and levels of conjugated and unconjugated bile acid species. Patients with duration of cholestasis < 6 months (n = 30) had significantly higher baseline cortisol levels than those with long standing cholestasis (> 6 months), together with higher bilirubin levels. CONCLUSIONS: We find no evidence of adrenal insufficiency in non-cirrhotic patients with cholestasis. In contrast, patients with cholestasis show hypercortisolism associated with disease severity as mirrored by levels of bilirubin. Lack of ACTH increase in cholestasis suggests a direct effect of cholestasis on adrenals and not on the pituitary gland. Further studies are needed to elucidate the mechanism of cortisol elevation in patients with cholestasis and its clinical significance.

Cholemic Nephropathy Reloaded.

Acute kidney injury (AKI) is a dreaded complication in patients with liver disease and jaundice, since it is associated with significant morbidity and mortality. Cholemic nephropathy (CN) is thought to represent a widely underestimated important cause of AKI in advanced liver diseases with jaundice. The umbrella term CN describes impaired renal function along with histomorphological changes consisting of intratubular cast formation and tubular epithelial cell injury directed primarily toward distal nephron segments. In cholestasis, biliary constituents may be excreted via the kidney and bilirubin or bile acids may trigger tubular injury and cast formation, but as we begin to understand the underlying pathophysiologic mechanisms, we become increasingly aware of the urgent need for clearly defined diagnostic criteria. In the following, we aim to summarize current knowledge of clinical and morphological characteristics of CN, discuss potential pathomechanisms, and raise key questions to stimulate evolution of a research strategy for CN.

FXR-dependent Rubicon induction impairs autophagy in models of human cholestasis.

BACKGROUND & AIMS: Cholestasis comprises a spectrum of liver diseases characterized by the accumulation of bile acids. Bile acids and activation of the farnesoid X receptor (FXR) can inhibit autophagy, a cellular self-digestion process necessary for cellular homeostasis and regeneration. In mice, autophagy appears to be impaired in cholestasis and induction of autophagy may reduce liver injury. METHODS: Herein, we explored autophagy in human cholestasis in vivo and investigated the underlying molecular mechanisms in vitro. FXR chromatin immunoprecipitation-sequencing and qPCR were performed in combination with luciferase promoter studies to identify functional FXR binding targets in a human cholestatic liver sample. RESULTS: Autophagic processing appeared to be impaired in patients with cholestasis and in individuals treated with the FXR ligand obeticholic acid (OCA). In vitro, chenodeoxycholic acid and OCA inhibited autophagy at the level of autophagosome to lysosome fusion in an FXR-dependent manner. Rubicon, which inhibits autophago-lysosomal maturation, was identified as a direct FXR target that is induced in cholestasis and by FXR-agonistic bile acids. Genetic inhibition of Rubicon reversed the bile acid-induced impairment of autophagic flux. In contrast to OCA, ursodeoxycholic acid (UDCA), which is a non-FXR-agonistic bile acid, induced autophagolysosome formation independently of FXR, enhanced autophagic flux and was associated with reduced Rubicon levels. CONCLUSION: In models of human cholestasis, autophagic processing is impaired in an FXR-dependent manner, partly resulting from the induction of Rubicon. UDCA is a potent inducer of hepatic autophagy. Manipulating autophagy and Rubicon may represent a novel treatment concept for cholestatic liver diseases. LAY SUMMARY: Autophagy, a cellular self-cleansing process, is impaired in various forms of human cholestasis. Bile acids, which accumulate in cholestatic liver disease, induce Rubicon, a protein that inhibits proper execution of autophagy. Ursodeoxycholic acid, which is the first-line treatment option for many cholestatic liver diseases, induces hepatic autophagy along with reducing Rubicon.

Histological demonstration of BSEP/ABCB11 inhibition in transient neonatal cholestasis: a case report.

BACKGROUND: Idiopathic or transient neonatal cholestasis (TNC) represents a group of cholestatic disorders with unidentified origin and remains a diagnosis of exclusion. Dysfunction of hepatobiliary transporters mediating excretion of biliary constituents from hepatocytes may play a central role in the pathogenesis of cholestasis. Despite variants of bile salt (BS) export pump (BSEP/ABCB11) have already been described in TNC, the pathogenic role of BSEP dysfunction in TNC remained so far elusive. CASE PRESENTATION: We report on a newly-identified heterozygous ABCB11 missense variant (c.1345G > A, p.Glu449Lys) which was associated with prolonged cholestasis in a term infant after a complicated neonatal period. Moreover, we show for the first time almost completely abolished BSEP expression on the hepatocellular membrane in TNC. CONCLUSION: This report demonstrates for the first time a close association between the prolonged cholestasis in infancy and impaired BSEP expression on the hepatocyte canalicular membrane in a heterozygous carrier of newly-identified ABCB11 variant.

Case of nasogastric tube dysfunction.

CLINICAL PRESENTATION: An elderly female patient was admitted to intensive care for prolonged vasopressor therapy and mechanical ventilation after cardiac arrest and acute percutaneous coronary intervention. Antiplatelet, thyroid hormone replacement and statin therapies were administered through a 14-French nasogastric tube (Nestlé Health Science) and enteral feeding was initiated. Correct position of the nasogastric tube was confirmed radiologically. On the seventh day in the intensive care, our patient was seen to regurgitate soft crumbs into her mouth. The blocked nasogastric tube was removed, but attempts to reinsert another tube failed.Upper GI endoscopy revealed an obstruction of the oesophagus with a milky-yellowish caseous substance 20 cm from the incisors (figure 1). The proximal part of the mass showed a central hole and ring-shaped layers resembling the cut face of a tree trunk.gutjnl;68/2/206/F1F1F1Figure 1Obstruction of the oesophagus with a milky-yellowish caseous substance. QUESTIONS: What caused the obstruction?How should we manage such a problem?

Metabolic disease and ABHD6 alter the circulating bis(monoacylglycerol)phosphate profile in mice and humans.

Bis(monoacylglycerol)phosphate (BMP) is a phospholipid that is crucial for lipid degradation and sorting in acidic organelles. Genetic and drug-induced lysosomal storage disorders (LSDs) are associated with increased BMP concentrations in tissues and in the circulation. Data on BMP in disorders other than LSDs, however, are scarce, and key enzymes regulating BMP metabolism remain elusive. Here, we demonstrate that common metabolic disorders and the intracellular BMP hydrolase α/ß-hydrolase domain-containing 6 (ABHD6) affect BMP metabolism in mice and humans. In mice, dietary lipid overload strongly affects BMP concentration and FA composition in the liver and plasma, similar to what has been observed in LSDs. Notably, distinct changes in the BMP FA profile enable a clear distinction between lipid overload and drug-induced LSDs. Global deletion of ABHD6 increases circulating BMP concentrations but does not cause LSDs. In humans, nonalcoholic fatty liver disease and liver cirrhosis affect the serum BMP FA composition and concentration. Furthermore, we identified a patient with a loss-of-function mutation in the ABHD6 gene, leading to an altered circulating BMP profile. In conclusion, our results suggest that common metabolic diseases and ABHD6 affect BMP metabolism in mice and humans.

Obeticholic acid may increase the risk of gallstone formation in susceptible patients.

BACKGROUND & AIMS: The nuclear farnesoid X receptor (FXR) agonist obeticholic acid (OCA) has been developed for the treatment of liver diseases. We aimed to determine whether OCA treatment increases the risk of gallstone formation. METHODS: Twenty patients awaiting laparoscopic cholecystectomy were randomized to treatment with OCA (25 mg/day) or placebo for 3 weeks until the day before surgery. Serum bile acids (BAs), the BA synthesis marker C4 (7α-hydroxy-4-cholesten-3-one), and fibroblast growth factor 19 (FGF19) were measured before and after treatment. During surgery, biopsies from the liver and the whole bile-filled gallbladder were collected for analyses of gene expression, biliary lipids and FGF19. RESULTS: In serum, OCA increased FGF19 (from 95.0 ±â€¯8.5 to 234.4 ±â€¯35.6 ng/L) and decreased C4 (from 31.4 ±â€¯22.8 to 2.8 ±â€¯4.0 nmol/L) and endogenous BAs (from 1,312.2 ±â€¯236.2 to 517.7 ±â€¯178.9 nmol/L; all p <0.05). At surgery, BAs in gallbladder bile were lower in patients that received OCA than in controls (OCA, 77.9 ±â€¯53.6 mmol/L; placebo, 196.4 ±â€¯99.3 mmol/L; p <0.01), resulting in a higher cholesterol saturation index (OCA, 2.8 ±â€¯1.1; placebo, 1.8 ±â€¯0.8; p <0.05). In addition, hydrophobic OCA conjugates accounted for 13.6 ±â€¯5.0% of gallbladder BAs after OCA treatment, resulting in a higher hydrophobicity index (OCA, 0.43 ±â€¯0.09; placebo, 0.34 ±â€¯0.07, p <0.05). Gallbladder FGF19 levels were 3-fold higher in OCA patients than in controls (OCA, 40.3 ±â€¯16.5 ng/L; placebo, 13.5 ±â€¯13.1 ng/ml; p <0.005). Gene expression analysis indicated that FGF19 mainly originated from the gallbladder epithelium. CONCLUSIONS: Our results show for the first time an enrichment of FGF19 in human bile after OCA treatment. In accordance with its murine homolog FGF15, FGF19 might trigger relaxation and filling of the gallbladder which, in combination with increased cholesterol saturation and BA hydrophobicity, would enhance the risk of gallstone development. LAY SUMMARY: Obeticholic acid increased human gallbladder cholesterol saturation and bile acid hydrophobicity, both decreasing cholesterol solubility in bile. Together with increased hepatobiliary levels of fibroblast growth factor 19, our findings suggest that pharmacological activation of the farnesoid X receptor increases the risk of gallstone formation. Clinical trial number: NCT01625026.

Bile acids increase steroidogenesis in cholemic mice and induce cortisol secretion in adrenocortical H295R cells via S1PR2, ERK and SF-1.

BACKGROUND AND AIMS: Bile acids are now accepted as central signalling molecules for the regulation of glucose, amino acid and lipid metabolism. Adrenal gland cortex cells express the bile acid receptors farnesoid X receptor (FXR), the G protein-coupled bile acid receptor (TGR5) and the sphingosine-1-phosphate receptor 2 (S1PR2). We aimed to determine the effects of cholestasis and more specifically of bile acids on cortisol production. METHODS: FXR and TGR5 knockout mice and controls were subjected to common bile duct ligation (CBDL) or chenodeoxycholic acid (CDCA) feeding to model cholestasis. Human adrenocortical H295R cells were challenged with bile acids for mechanistic studies. RESULTS: We found that CBDL and CDCA feeding increased the levels of corticosterone, the rodent equivalent to human cortisol and mRNA and protein levels of steroidogenesis-related enzymes in adrenals independent of FXR and TGR5. Taurine-conjugated CDCA (TCDCA) significantly stimulated cortisol secretion, phosphorylation of extracellular signal-regulated kinase (ERK) and expression of steroidogenesis-related genes in human adrenocortical H295R cells. FXR and TGR5 agonists failed to induce cortisol secretion in H295R cells. S1PR2 inhibition significantly abolished TCDCA-induced cortisol secretion, lowered phosphorylation of ERK and abrogated enhanced transcription of steroidogenesis-related genes in H295R cells. Likewise, siRNA S1PR2 treatment reduced the phosphorylation of ERK and cortisol secretion. Steroidogenic factor-1 (SF-1) transactivation activity was increased upon TCDCA treatment suggesting that bile acid signalling is linked to SF-1. Treatment with SF-1 inverse agonist AC45594 also reduced TCDCA-induced steroidogenesis. CONCLUSIONS: Our findings indicate that supraphysiological bile acid levels as observed in cholestasis stimulate steroidogenesis via an S1PR2-ERK-SF-1 signalling pathway.

Chronic gastric ulcer disease complicating selective internal radiation therapy (SIRT) in a patient with cholangiocellular carcinoma.

Selective internal radiation therapy (SIRT) is a therapeutic option for primary and metastatic liver tumors. Microspheres containing Yttrium 90, a beta-emitting radionuclide, are administered into the hepatic artery allowing selective internal radiation of a liver tumor. SIRT-related complications may appear due to migration of the radiation microspheres to organs distant from the tumor site. In order to prevent these complications, unintended non target embolization of Yttrium microspheres has to be avoided. However, data from external-beam radiation therapy (EBRT) suggests that the stomach/small bowel may actually be less radiosensitive than the liver. Gastric ulcers, a well-known SIRT-related complication, may therefore not only be caused by local radiation but also by unusual accumulation of microspheres in the submucosa and small vessel damage. We herein report a more than two- year-long persisting, highly symptomatic, non-neoplastic ulceration of the gastric antrum leading to pyloric stenosis caused by SIRT therapy with Yttrium 90 microspheres for the treatment of intrahepatic cholangiocellular carcinoma. The chronic courses of the ulcer disease together with the specific histological features highlight the pivotal role of radiation-induced small vessel damage in SIRT-induced adverse events.