A multicenter survey on endoscopic retrograde cholangiopancreatography during the COVID-19 pandemic in northern and central Italy

Background and study aims  COVID-19 has dramatically impacted endoscopy practice because upper endoscopy procedures can be aerosol-generating. Most elective procedures have been rescheduled. Endoscopic retrograde cholangiopancreatography (ERCP) is frequently performed in emergency or urgent settings in which rescheduling is not possible. We evaluated the impact of the COVID-19 pandemic on ERCP in Italy during the SARS-CoV-2 lockdown, in areas with high incidence of COVID-19. Patients and methods  We performed a retrospective survey of centers performing ERCP in high COVID-19 prevalence areas in Italy to collect information regarding clinical data from patients undergoing ERCP, staff, case-volume and organization of endoscopy units from March 8, 2020 to April 30, 2020. Results  We collected data from 31 centers and 804 patients. All centers adopted a triage and/or screening protocol for SARS-CoV-2 and performed follow-up of patients 2 weeks after the procedure. ERCP case-volume was reduced by 44.1 % compared to the respective 2019 timeframe. Of the 804 patients undergoing ERCP, 22 (2.7 %) were positive for COVID-19. Adverse events occurred at a similar rate to previously published data. Of the patients, endoscopists, and nurses, 1.6 %, 11.7 %, and 4.9 %, respectively, tested positive for SARS-CoV-2 at follow up. Only 38.7 % of centers had access to a negative-pressure room for ERCP. Conclusion  The case-volume reduction for ERCP during lockdown was lower than for other gastrointestinal endoscopy procedures. No definitive conclusions can be drawn about the percentage of SARS-CoV-2-positive patients and healthcare workers observed after ERCP. Appropriate triage and screening of patients and adherence to society recommendations are paramount.

Clinical and patient reported outcomes of the multidisciplinary management in patients with inflammatory bowel disease-associated spondyloarthritis

OBJECTIVE

Arthritis is the most frequent extra-intestinal manifestation in patients with inflammatory bowel diseases (IBD). The coexistence of intestinal and articular inflammation advocates the need for a multidisciplinary management of patients with IBD-associated spondyloarthritis.

METHODS

Consecutive IBD patients were evaluated jointly by the gastroenterologist and the rheumatologist in a combined clinic. All the patients were assessed and screened for articular involvement, disease activity and health related quality of life. After the prescription of a shared treatment, patients with spondyloarthritis were followed up for 24 months.

RESULTS

Two hundred sixty-two IBD patients, including 80 who were classified as affected by spondyloarthritis according to the ASAS criteria, were included in the study. At baseline, patients with both IBD and spondyloarthritis showed worse quality of life in both the physical and mental domains. The multidisciplinary management provided a significant improvement of gastrointestinal and articular manifestations, as well as the health-related quality of life. Moreover, global and gastrointestinal-specific quality of life significantly correlated with articular disease activity.

CONCLUSION

The multidisciplinary management significantly improves both articular and gastrointestinal disease activities and the quality of life of patients with IBD-associated spondyloarthritis. An appropriate screening strategy and the integrated management of these patients should be encouraged and employed in clinical practice.

Effectiveness of Laser Photoradiation Therapy following Hematoporphyrin Derivative Administration in the Experimental MS-2 Tumor Model

The effectiveness of laser photoradiation therapy with hematoporphyrin derivative sensitization was tested in the MS-2 sarcoma. This solid tumor, transplanted into the pad of the hind leg of BALB/c mice, was found to be a sensitive experimental model for a quantitative evaluation of response to phototherapy and for determination of critical parameters in laser phototherapy treatment. Under our experimental conditions, optimal therapeutic effects appeared to be critically dependent on drug dose, number of treatments, light intensity, and irradiation of the peripheral border of the tumor.

Hyperthermal Effects in Phototherapy with Hematoporphyrin Derivative Sensitization

Although the photochemical reaction of hematoporphyrin derivative (HpD) appears to play a major role in cytotoxic activity, the hyperthermal contribution to tumor destruction has not yet been clarified. We investigated its role in the effectiveness of laser photoradiation therapy using MS-2 sarcoma transplanted into the hind pad of BALB/c mice as the experimental model. Mice received HpD i.V., 25 mg/kg - 24 h before exposure to light delivered from a dye laser or Nd-YAG laser, or before warming in a thermostated bath. Since our aim was not to cure the tumor, the treatment response was evaluated only as inhibition of tumor growth at different days after treatment. Our results support the view that in laser photochemotherapy the hyperthermia produced by irradiation and the photodynamic effect mediated by HpD could contribute to tumor destruction. Moreover, a synergistic interaction between the photodynamic effect and heat was observed in this experimental model.

Trend of Total and District Activity in Patients Subjected to Intralymphatic Radiotherapy

The aim of this paper is to determine the dose received by every organ of patients subjected to intralymphatic radiotherapy with Lipiodol F181I. For this purpose external counting techniques have been devised for determining the effective half-life (Te). The determination of the initial concentration (Co) will be considered in a subsequent paper. Systematic checks were carried out on 9 patients with a Nukab scanner by means of sectorial counts, total body scanning and body profiles. By measuring the areas of successive profiles in the same patient, the effective half-life of the radioactive substance in the different body sections could be exactly determined. No shifting of the medium from the abdominal to the thoracic region by direct lymphatic route could be detected from the first day after lymphography until almost total decay of 131I. The trend of radioactivity accumulation in the lung was studied during injection and during the first few hours after lymphography. Some hypotheses as to the trend of activity in the various body districts and the possible metabolic routes of the medium in the body are advanced.

Laser Phototherapy following HpD Administration in Superficial Neoplastic Lesions

We report our preliminary clinical experience with hematoporphyrin derivative (HpD) injection and argon or dye laser irradiation for the treatment of 61 surface neoplastic lesions in 7 patients. Forty-three sites were multiple basal cell carcinoma in 5 patients, and the remaining 18 were cutaneous and subcutaneous recurrent breast carcinoma after mastectomy in the thoracic wall. The patients were selected on the basis of the lack of indication for conventional therapeutic modalities. The selection of irradiation procedures and laser source was based on the thickness of the lesion and extension of the disease. The photochemical reaction between HpD injected i.v. at a dose of 3 mg/kg body weight and the laser beam at a dose of 60 to 120 J/cm2 resulted in 75 % favorable responses at the treated sites. Optimal therapeutic effects appeared to be critically dependent on total light dose and tumor infiltration patterns. The phototherapeutic technique proved to be effective in selected cases of neoplastic lesions, especially when conventional treatment modalities were poorly indicated or contraindicated.

Radioactivity in the Lungs after Intralymphatic Radiotherapy with Lipiodol F 131I

A follow-up to earlier studies on the biological behavior of Lipiodol F 131I injected into lymph vessels of the foot for intralymphatic radiotherapy. A series of investigations on the trend of the activity in the lungs was conducted using various external measurements. It was found that the radioiodide accumulation was considerable and that it was eliminated more rapidly than from the lymph nodes. An explanation of the build-up of radioactivity in the lungs is suggested.

Topical Administration of Tetrasodium-Mesotetraphenyl-Porphinesulfonate (TPPS): Correlation between Drug Penetration and Depth of Necrosis in Skin of Nude Mice following Red Light Irradiation

The main side effect in photodynamic therapy is photosensitization of the patient's skin following systemic administration of the photosensitizing agent. In the case of superficial lesions, this problem can be avoided by topically applying the drug: in this way a local treatment can be performed. We tested the photosensitizing properties of a 2 % solution of TPPS (tetrasodium-tetraphenylporphinesulfonate) in a vehicle containing a penetration enhancer, Azone, on skin of nude mice. An aliquot of 0.1 ml/cm2 of the solution was painted on the skin overlying an s.c. implanted NMU-1 tumor. Subsequently, animals were sacrificed at different times after application. Fluorescence microscopy revealed that TPPS penetration depth was related to time elapsed after application and to painting modalities. Solution penetration was enhanced by wiping with ether immediately before painting. Irradiation at 80 mW/cm2 for 20 min with a dye laser emitting at 640 am, 4 h after TPPS application, produced necrosis of the upper skin layers, up to 0.2 mm in depth. These findings suggest that topical TPPS administration, followed by laser irradiation, may be a suitable treatment modality for skin lesions involving epithelial layers, even though several aspects of this metodology need further investigation.

Sclerostin and Antisclerostin Antibody Serum Levels Predict the Presence of Axial Spondyloarthritis in Patients with Inflammatory Bowel Disease

OBJECTIVE

The early diagnosis of inflammatory bowel disease (IBD)-associated spondyloarthritis (SpA/IBD) in patients affected by IBD represents a major topic in clinical practice; in particular, to date there are no available serum biomarkers revealing the presence of joint inflammation in these patients. Sclerostin (SOST), an antagonist of the Wnt/β-catenin pathway, and antisclerostin-immunoglobulin G (anti-SOST-IgG) have been recently studied in patients with ankylosing spondylitis (AS) as a putative marker of disease activity.

METHODS

SOST and anti-SOST-IgG serum levels were assayed in 125 patients with IBD, 85 with axial or peripheral SpA, and in control groups (patients with AS and rheumatoid arthritis, and healthy individuals). The diagnostic performance in discriminating the presence of SpA/IBD was assessed for both candidate biomarkers.

RESULTS

Patients affected by SpA/IBD with axial involvement displayed significantly lower levels of SOST and higher levels of anti-SOST-IgG compared to patients with only peripheral arthritis, IBD, and controls. Moreover, SOST and anti-SOST-IgG serum levels were inversely correlated and were associated with the duration of articular symptoms. Both biomarkers showed good accuracy in predicting the presence of axial SpA in patients with IBD.

CONCLUSION

We demonstrated that in patients with IBD, SOST and anti-SOST-IgG might represent novel biomarkers to assess the presence of axial joint involvement. Moreover, the development of anti-SOST-IgG and the subsequent decrease of SOST serum levels could play a role in the pathogenesis of SpA/IBD.

Gut Microbiota and Alcoholic Liver Disease

The gut-liver axis model has often explained liver disease physiopathology. Among the latter we can mention Non-Alcoholic Liver Steatosis (NAFLD), Liver Steatohepatitis (NASH), liver cirrhosis. In this frame an altered Intestinal Permeability (IP) is the gate for antigenic/toxic substances from gut lumen until target organs such as liver in NAFLD. Altered intestinal permeability was discovered almost forty years ago as consequence of acute and chronic alcohol ingestion. Alcohol Liver Disease (ALD) is a systemic pathology whose beginning and end belong to the intestine. Several recent evidences from the literature show how gut microbiota composition can be altered by alcohol, affects IP and can be modulated by several nonpharmacological and pharmacological agents, becoming the target for ALD treatment. In this review we describe the definition of ALD, gut microbiota composition in healthy and ALD, definition and role of IP in ALD physiopathology and emerging evidences on gut microbiota modulation in ALD treatment from preliminary clinical and non-clinical studies.

ALPPS Procedure for Extended Liver Resections: A Single Centre Experience and a Systematic Review

Aim

To report a single-centre experience with the novel Associating Liver Partition and Portal vein ligation for Staged hepatectomy (ALPPS) technique and systematically review the related literature.

Methods

Since January 2013, patients with extended primary or secondary liver tumors whose future liver remnant (FLR) was considered too small to allow hepatic resection were prospectively assessed for the ALPPS procedure. A systematic literature search was performed using PubMed, Scopus and the Cochrane Library Central.

Results

Until July 2014 ALPPS was completed in 9 patients whose mean age was 60±8 years. Indications for surgical resection were metastases from colorectal cancer in 3 cases, perihilar cholangiocarcinoma in 3 cases, intrahepatic cholangiocarcinoma in 2 cases and hepatocellular carcinoma without chronic liver disease in 1 case. The calculated FLR volume was 289±122 mL (21.1±5.5%) before ALPPS-1 and 528±121 mL (32.2±5.7%) before ALLPS-2 (p<0.001). The increase in FLR between the two procedures was 96±47% (range: 24–160%, p<0.001). Additional interventions were performed in 4 cases: 3 patients underwent Roux-en-Y hepaticojejunostomy, and one case underwent wedge resection of a residual tumor in the FLR. The average time between the first and second step of the procedure was 10.8±2.9 days. The average hospital stay was 24.1±13.3 days. There was 1 postoperative death due to hepatic failure in the oldest patient of this series who had a perihilar cholangiocarcinoma and concomitant liver fibrosis; 11 complications occurred in 6 patients, 4 of whom had grade III or above disease. After a mean follow-up of 17.1±8.5 months, the overall survival was 89% at 3–6 and 12 months. The recurrence-free survival was 100%, 87.5% and 75% at 3-6-12 months respectively. The literature search yielded 148 articles, of which 22 articles published between 2012 and 2015 were included in this systematic review.

Conclusion

The ALPPS technique effectively increased the resectability of otherwise inoperable liver tumors. The postoperative morbidity in our series was high in accordance with the data from the systematic review. Age, liver fibrosis and presence of biliary stenting were predisposing factors for postoperative morbidity and mortality.

[Tenofovir and entecavir for chronic hepatitis B infection treatment: a single-center experience]

BACKGROUND AND AIM: The current treatment of chronic hepatitis B infection (CHBV) has achieved several step-ups thanks to the introduction of the new-generation nucleos(t)ide analogs. Entecavir and tenofovir have shown a high genetic resistance barrier and a low rate of side effects. In literature, there are a few studies comparing entecavir and tenofovir in the treatment of CHBV. Thus, we describe the results of our experience in managing CHBV patients with tenofovir vs. entecavir.MATERIALS AND METHODS: We have retrospectively evaluated, from 2007 to date, 20 CHBV patients treated with entecavir and tenofovir. All the patients underwent basal and periodical clinical follow-up, blood tests, virological tests, Fibroscan® test or liver biopsy and also upper abdominal ultrasound examination. Study endpoints were: viral replication inhibition, viral antigens seroconversion and transaminases normalization. Drug-associated side effects were also registered.RESULTS: After 12 weeks of therapy, entecavir and tenofovir lead to HBV-DNA negativization in 44% and 62% of patients, respectively. A case of viral seroconversion for HBeAg and HBsAg was evident in entecavir group, while no cases were registered in tenofovir group. After 12 weeks, 11% of entecavir treated patients and 37% of tenofovir treated patients showed normalization of transaminases.DISCUSSION: Tenofovir seems to exert a better viral replication inhibition (though not statistically significant) and to show transaminases improvement in comparison with entecavir, which, in turn, results more effective in HBeAg/HBsAg seroconversion. Both drugs have a high safety profile in terms of side effects.[Article in Italian]

[Therapeutic decisions and treatment with sorafenib in hepatocellular carcinoma: final analysis of GIDEON study in Italy]

INTRODUCTION

Sorafenib, an oral multikinase inhibitor, is the only targeted agent approved for the treatment of patients with hepatocellular carcinoma (HCC) after demonstration to increase overall survival compared to placebo in two randomized phase III study. GIDEON (Global Investigation of therapeutic DEcisions in HCC and Of its treatment with sorafeNib) is the largest, global, non-interventional, prospective study of patients with uHCC (n>3200) treated with sorafenib in real-life clinical practice conditions. Here we report the final analysis of safety and efficacy in the Italian cohort of patients.

METHODS

Patients with unresectable HCC who are candidates for systemic therapy, and for whom a decision has been made to treat with sorafenib, are eligible for inclusion. Patients demographics disease characteristics and treatment history were recorded at baseline visit. Sorafenib dose, concomitant medications, performance status, liver function, adverse events and efficacy (survival and response rate) were collected throughout the study.

RESULTS

In the Italian cohort of the GIDEON study 278 patients were included in 36 centers. The global rate of adverse events was 81%. Drug-related events accounted for 67%, mostly of grade 1 and 2, and only 8% were classified as serious. The most common were diarrhea (24%), fatigue (23%), dermatological (14%), rash/exfoliation (10%), hypertension (9%), hemorrage/bleeding of gastrointestinal tract (6%). Overall survival was 14.4 months and time to progression 6.2 months. Objective responses were observed in 14 patients (5%) with 3 complete responses (1%). Stable diseases of at least 6 weeks were observed in 113 patients (41%) with a 30% of disease control rate.

DISCUSSION

The safety profile of sorafenib in terms of rate and type of adverse events is similar to that emerged in the global international GIDEON study as well as in the pivotal registration studies.

KRAS and BRAF mutations and MSI status in precursor lesions of colorectal cancer detected by colonoscopy

Colorectal cancer (CRC) is one of the most frequent cancers worldwide. Adenoma is the main precursor lesion and, recently, the serrated polyps were described as a group of colorectal lesions with malignant potential. The morphologic and biologic characterizations of serrated polyps remain limited. The aim of the present study was to determine the frequency of KRAS and BRAF mutations and microsatellite instability (MSI) in CRC precursor lesions, to evaluate the association between molecular, pathologic and morphologic alterations in precursor lesions and to compare with the alterations detected in CRC. A series of 342 precursor lesions were removed from 155 patients during colonoscopy. After morphologic classification, molecular analysis was performed in 103 precursor lesions, and their genetic profile compared with 47 sporadic CRCs. Adenomas were the main precursor lesions (70.2%). Among the serrated polyps, the main precursor lesion was hyperplastic polyps (HPs) (82.4%), followed by sessile serrated adenomas (12.7%) and traditional serrated adenomas (2.0%). KRAS mutations were detected in 13.6% of the precursor lesions, namely in adenomas and in HPs, but in no serrated adenoma. BRAF mutations were found in 9 (8.7%) precursor lesions, mainly associated with serrated polyps and absent in adenomas (P<0.001). High MSI (MSI-H) was absent in precursor lesions. In the 47 CCR cases, 46.8% exhibited KRAS mutation, 6.5% BRAF mutations and 10.6% MSI-H. This study confirms the role of KRAS and BRAF mutations in CRC carcinogenesis, a crucial step in implementing CRC screening strategies.

VEGF and VEGFR genotyping in the prediction of clinical outcome for HCC patients receiving sorafenib: the ALICE-1 study

Although new treatment modalities changed the global approach to hepatocellular carcinoma (HCC), this disease still represents a medical challenge. Currently, the therapeutic stronghold is sorafenib, a tyrosine kinase inhibitor (TKI) directed against the vascular endothelial growth factor (VEGF) family. Previous observations suggested that polymorphisms of VEGF and its receptor (VEGFR) genes may regulate angiogenesis and lymphangiogenesis and thus tumour growth control. The aim of our study was to evaluate the role of VEGF and VEGFR polymorphisms in determining the clinical outcome of HCC patients receiving sorafenib. From a multicentre experience 148 samples (tumour or blood samples) of HCC patients receiving sorafenib were tested for VEGF-A, VEGF-C and VEGFR-1,2,3 single nucleotide polymorphisms (SNPs). Patients' progression-free survival (PFS) and overall survival (OS) were analysed. At univariate analysis VEGF-A alleles C of rs25648, T of rs833061, C of rs699947, C of rs2010963, VEGF-C alleles T of rs4604006, G of rs664393, VEGFR-2 alleles C of rs2071559, C of rs2305948 were significant predictors of PFS and OS. At multivariate analysis rs2010963, rs4604006 and BCLC (Barcelona Clinic Liver Cancer) stage resulted to be independent factors influencing PFS and OS. Once prospectively validated, the analysis of VEGF and VEGFR SNPs may represent a clinical tool to better identify HCC patients more likely to benefit from sorafenib. On the other hand, the availability of more accurate predictive factors could help avoiding unnecessary toxicities to potentially resistant patients who may be optimal candidates for different treatments interfering with other tumour molecular pathways.

An oestrogen receptor β-selective agonist exerts anti-neoplastic effects in experimental intrahepatic cholangiocarcinoma

BACKGROUND

Cholangiocarcinoma cells over-express oestrogen receptor-β, which displays anti-proliferative and pro-apoptotic effects.

AIM

To evaluate the effects of a newly developed and highly selective oestrogen receptor-β agonist (KB9520) on experimental intrahepatic cholangiocarcinoma.

METHODS

In vitro, the effects of KB9520 on apoptosis and proliferation of HuH-28 cells, HuH-28 cells with selective oestrogen receptor-β silencing (by small interfering RNA), HepG2 cells (oestrogen receptor-α and oestrogen receptor-β negative) and HepER3 cells (HepG2 cells transformed to stably express oestrogen receptor-α) were evaluated. In vivo, the effects of KB9520 on experimental intrahepatic cholangiocarcinoma, induced by thioacetamide administration were tested.

RESULTS

In vitro, KB9520 induced apoptosis and inhibited proliferation of HuH-28 cells. KB9520 effects were absent in cells lacking oestrogen receptor-α and β (HepG2) and in cells expressing only oestrogen receptor-α (HepER3); its pro-apoptotic effect was impaired in cells where oestrogen receptor-β expression was decreased by specific small interfering RNA. In vivo, KB9520 inhibited experimental intrahepatic cholangiocarcinoma development in thioacetamide-treated rats and promoted tumour regression in rats where tumour was already established. In treated animals, tumour areas showed reduced proliferation but increased apoptosis.

CONCLUSIONS

KB9520 induced apoptosis in cholangiocarcinoma by selectively acting on oestrogen receptor-β, suggesting that oestrogen receptor-β selective agonists may be a novel and effective therapeutic option for the medical treatment of intrahepatic cholangiocarcinoma.

Neuropeptide Y inhibits cholangiocarcinoma cell growth and invasion

No information exists on the role of neuropeptide Y (NPY) in cholangiocarcinoma growth. Therefore, we evaluated the expression and secretion of NPY and its subsequent effects on cholangiocarcinoma growth and invasion. Cholangiocarcinoma cell lines and nonmalignant cholangiocytes were used to assess NPY mRNA expression and protein secretion. NPY expression was assessed by immunohistochemistry in human liver biopsies. Cell proliferation and migration were evaluated in vitro by MTS assays and matrigel invasion chambers, respectively, after treatment with NPY or a neutralizing NPY antibody. The effect of NPY or NPY depletion on tumor growth was assessed in vivo after treatment with NPY or the neutralizing NPY antibody in a xenograft model of cholangiocarcinoma. NPY secretion was upregulated in cholangiocarcinoma compared with normal cholangiocytes. Administration of exogenous NPY decreased proliferation and cell invasion in all cholangiocarcinoma cell lines studied and reduced tumor cell growth in vivo. In vitro, the effects of NPY on proliferation were blocked by specific inhibitors for NPY receptor Y2, but not Y1 or Y5, and were associated with an increase in intracellular d-myo-inositol 1,4,5-trisphosphate and PKCα activation. Blocking of NPY activity using a neutralizing antibody promoted cholangiocarcinoma growth in vitro and in vivo and increased the invasiveness of cholangiocarcinoma in vitro. Increased NPY immunoreactivity in human tumor tissue occurred predominantly in the center of the tumor, with less expression toward the invasion front of the tumor. We demonstrated that NPY expression is upregulated in cholangiocarcinoma, which exerts local control on tumor cell proliferation and invasion. Modulation of NPY secretion may be important for the management of cholangiocarcinoma.

Cholangiocarcinoma in Italy: A national survey on clinical characteristics, diagnostic modalities and treatment. Results from the "Cholangiocarcinoma" committee of the Italian Association for the Study of Liver disease

BACKGROUND

Very few studies assessed cholangiocarcinoma clinical characteristics.

AIM

To evaluate the clinical characteristics of intra-hepatic (IH) and extra-hepatic (EH)-CCA.

METHODS

We performed a national survey based on a questionnaire.

RESULTS

218 cholangiocarcinomas were observed (47% EH-CCA, 53% IH-CCA) with an age at the diagnosis higher for EH-CCA. Coexistence of cirrhosis or viral cirrhosis was more frequent in IH-CCA than EH-CCA. An incidental asymptomatic presentation occurred in 28% of IH-CCA vs 4% EH-CCA whilst, 74% EH-CCA vs 28% IH-CCA presented with jaundice. 91% of IH-CCA presented as a single intra-hepatic mass, whilst 50% of EH-CCA was peri-hilar. In the diagnostic work-up, 70% of all cholangiocarcinoma cases received at least 3 different imaging procedures. Tissue-proven diagnosis was obtained in 80% cholangiocarcinoma. Open surgery with curative intent was performed in 45% of IH-CCA and 29% EH-CCA. 18% IH-CCA vs 4% EH-CCA did not received treatment.

CONCLUSIONS

In Italy IH-CCA is managed as frequently as EH-CCA. In comparison to EH-CCA, IH-CCA occurs at younger age and is more frequently associated with cirrhosis and with an incidental asymptomatic presentation. In contrast, most EH-CCAs are jaundiced at the diagnosis. Cholangiocarcinoma diagnostic management is cost- and time-consuming with curative surgical treatment applicable more frequently in IH-CCA.

Assessment of airborne soy-hull allergen (Gly m 1) in the Port of Ancona, Italy

BACKGROUND

Epidemic asthma outbreaks are potentially a very high-risk medical situation in seaport towns where large volumes of soybean are loaded and unloaded Airborne allergen assessment plays a pivotal role in evaluating the resulting environmental pollution.

OBJECTIVE

The aim of this study was to measure the airborne Gly m 1 allergen level in the seaport of Ancona in order assess the soybean-specific allergenic risk for the city.

METHODS

Allergen and PM10 were evaluated at progressive distances from the port area. Allergen analysis was performed by monoclonal antibody-based immunoassay on the sampled filters. Daily meteorological data were obtained from the local meteorological station. For estimating the assimilative capacity of the atmosphere, an approach based on dispersive ventilation coefficient was tried.

RESULTS

The allergen concentrations detected were low (range = 0.4-171 ng/m3). A decreasing gradient of the airborne allergen from the unloading area (22.1 +/- 41.2 ng/m3) to the control area (0.6 +/- 0.7 ng/m3) was detected. The concentration of the airborne Gly m 1 was not coupled with the presence of the soy-carrying ships in the port. A statistically significant relationship between airborne allergen, PM10 and local meteorological parameters quantifies the association with the atmospheric condition.

CONCLUSION

Airborne Gly m 1 is part of the atmospheric dust of Ancona. The low level of this allergen seems consistent with the absence of asthma epidemic outbreak.

Molecular mechanisms of cholangiocarcinoma

Cholangiocarcinoma (CC), the malignant tumor of the epithelial cells lining the biliary ducts, has undergone a worldwide increase in incidence and mortality. The malignant transformation of the biliary cells originates from a multistep process evolving through chronic inflammation of the biliary tract to CC. In the last few years several advances have been towards understanding and clarifying the molecular mechanisms implicated in the cholangiocarcinogenesis process. However, many pathophysiologic aspects governing the growth of CC are still undefined. The poor prognosis of this tumor underlines the urgent need to codify the underlying molecular mechanisms involved in the growth and progression of CC in order to design effective preventive measures and valid treatment regimens. This review reports on progresses made in the last few years in clarifying the molecular pathways involved in the process of cholangiocarcinogenesis.

After damage of large bile ducts by gamma-aminobutyric acid, small ducts replenish the biliary tree by amplification of calcium-dependent signaling and de novo acquisition of large cholangiocyte phenotypes

Large cholangiocytes secrete bicarbonate in response to secretin and proliferate after bile duct ligation by activation of cyclic adenosine 3', 5'-monophosphate signaling. The Ca(2+)-dependent adenylyl cyclase 8 (AC8, expressed by large cholangiocytes) regulates secretin-induced choleresis. Ca(2+)-dependent protein kinase C (PKC) regulates small cholangiocyte function. Because gamma-aminobutyric acid (GABA) affects cell functions by activation of both Ca(2+) signaling and inhibition of AC, we sought to develop an in vivo model characterized by large cholangiocyte damage and proliferation of small ducts. Bile duct ligation rats were treated with GABA for one week, and we evaluated: GABA(A), GABA(B), and GABA(C) receptor expression; intrahepatic bile duct mass (IBDM) and the percentage of apoptotic cholangiocytes; secretin-stimulated choleresis; and extracellular signal-regulated kinase1/2 (ERK1/2) phosphorylation and activation of Ca(2+-)dependent PKC isoforms and AC8 expression. We found that both small and large cholangiocytes expressed GABA receptors. GABA: (i) induced apoptosis of large cholangiocytes and reduced large IBDM; (ii) decreased secretin-stimulated choleresis; and (iii) reduced ERK1/2 phosphorylation and AC8 expression in large cholangiocytes. Small cholangiocytes: (i) proliferated leading to increased IBDM; (ii) displayed activation of PKCbetaII; and (iii) de novo expressed secretin receptor, cystic fibrosis transmembrane regulator, Cl(-)/HCO(3)(-) anion exchanger 2 and AC8, and responded to secretin. Therefore, in pathologies of large ducts, small ducts replenish the biliary epithelium by amplification of Ca(2+)-dependent signaling and acquisition of large cholangiocyte phenotypes.

Completely isolated enteric duplications cysts: a survey of four cases

Enteric duplication cysts are uncommon congenital abnormalities with epithelial lining. They are cystic or tubular structures intimately attached to a portion of the gastrointestinal tract; they are usually located on the mesenteric site of the digestive tract sharing common blood supply. Isolated cystic duplications are an extremely rare variant with their own blood supply: in literature only five cases have been reported. We present our four cases series of this uncommon anomaly.

Endothelin inhibits cholangiocarcinoma growth by a decrease in the vascular endothelial growth factor expression

BACKGROUND

Endothelins (ET-1, ET-2, ET-3) are peptides with vasoactive properties interacting with ET(A) and ET(B) receptors. ET-1 inhibits secretin-stimulated ductal secretion (hallmark of cholangiocyte growth) of cholestatic rats by interaction with ET receptors.

AIM

The aims of the studies were to evaluate (i) the effect of ET-1 on cholangiocarcinoma growth in Mz-ChA-1 cells and nude mice and (ii) whether ET-1 regulation of cholangiocarcinoma growth is associated with changes in the expression of vascular endothelial growth factor-A (VEGF-A), VEGF-C, VEGF receptor-2 (VEGFR-2) and VEGFR-3.

METHODS

We determined the expression of ET(A) and ET(B) receptors on normal and malignant (Mz-ChA-1) cholangiocytes and human cholangiocarcinoma tissue and the effect of ET-1 on the proliferation and expression of VEGF-A, VEGF-C (regulators of tumour angiogenesis) and its receptors, VEGFR-2 and VEGFR-3, in Mz-ChA-1 cells. In vivo, Mz-ChA-1 cells were injected into the flanks of athymic mice and injections of ET-1 or saline into the tumours were performed daily. The effect of ET-1 on tumour size, cell proliferation, apoptosis, collagen quantity and the expression of VEGF-A and VEGF-C and VEGFR-2 and VEGFR-3 were measured after 73 days.

RESULTS

Higher expression of ET(A) and ET(B) was observed in malignant compared with normal cholangiocytes. ET-1 inhibited proliferation and VEGF-A, VEGF-C, VEGFR-2 and VEGFR-3 expression of Mz-ChA-1 cells. Chronic ET-1 treatment decreased tumour volume, tumour cell proliferation and VEGF-A and VEGF-C expression but increased apoptosis and collagen tissue deposition compared with controls.

CONCLUSIONS

Modulation of VEGF-A and VEGF-C (by ET-1) may be important for managing cholangiocarcinoma growth.

Exendin-4, a glucagon-like peptide 1 receptor agonist, protects cholangiocytes from apoptosis

BACKGROUND AND AIMS

Progression of chronic cholestatic disorders towards ductopenia results from the dysregulation of cholangiocyte survival, with cell death by apoptosis prevailing over compensatory proliferation. Currently, no therapy is available to sustain cholangiocyte survival in the course of those disorders. It was recently shown that cholangiocytes express the glucagon-like peptide-1 receptor (GLP-1R); its activation results in enhanced proliferative reaction to cholestasis. The GLP-1R selective agonist exendin-4 sustains pancreatic beta cell proliferation and prevents cell death by apoptosis. Exendin-4 is now employed in humans as a novel therapy for diabetes. The aim of the present study was to verify whether exendin-4 is effective in preventing cholangiocyte apoptosis.

METHODS

In vitro, tests were carried out to determine if exendin-4 is able to prevent apoptosis of cholangiocytes isolated from normal rats induced by glycochenodeoxycholic acid (GCDCA); in vivo, animals subjected to 1 week of bile duct ligation and to a single intraperitoneal injection of CCl(4) were treated with exendin-4 for 3 days.

RESULTS

Exendin-4 prevented GCDCA-induced Bax mitochondrial translocation, cytochrome c release and an increase in caspase 3 activity. Phosphatidylinositol 3-kinase, but not cAMP/protein kinase A or Ca(2+)/calmodulin-dependent protein kinase inhibitors, neutralised the effects of exendin-4. In vivo, exendin-4 administration prevented the increase in TUNEL (terminal deoxynucleotidyl transferase-mediated triphosphate end-labelling)-positive cholangiocytes and the loss of bile ducts observed in bile duct-ligated rats treated with CCl(4).

CONCLUSION

Exendin-4 prevents cholangiocyte apoptosis both in vitro and in vivo; such an effect is due to the ability of exendin-4 to counteract the activation of the mitochondrial pathway of apoptosis. These findings support the hypothesis that exendin-4 may be effective in slowing down the progression of cholangiopathies to ductopenia.

Human cholangiocarcinoma development is associated with dysregulation of opioidergic modulation of cholangiocyte growth

BACKGROUND/AIMS

Incidence of cholangiocarcinoma is increasing worldwide, yet remaining highly aggressive and with poor prognosis. The mechanisms that drive cholangiocyte transition towards malignant phenotype are obscure. Cholangiocyte benign proliferation is subjected to a self-limiting mechanism based on the autocrine release of endogenous opioid peptides. Despite the presence of both, ligands interact with delta opioid receptor (OR), but not with microOR, with the consequent inhibition of cell growth. We aimed to verify whether cholangiocarcinoma growth is associated with failure of opioidergic regulation of growth control.

METHODS

We evaluated the effects of OR selective agonists on cholangiocarcinoma cell proliferation, migration and apoptosis. Intracellular signals were also characterised.

RESULTS

Activation of microOR, but not deltaOR, increases cholangiocarcinoma cell growth. Such an effect is mediated by ERK1/2, PI3K and Ca(2+)-CamKIIalpha cascades, but not by cAMP/PKA and PKCalpha. microOR activation also enhances cholangiocarcinoma cell migration and reduces death by apoptosis. The anti-apoptotic effect of microOR was PI3K dependent.

CONCLUSIONS

Our data indicate that cholangiocarcinoma growth is associated with altered opioidergic regulation of cholangiocyte biology, thus opening new scenarios for future surveillance or early diagnostic strategies for cholangiocarcinoma.

Control of cholangiocyte adaptive responses by visceral hormones and neuropeptides

Cholangiocytes, the epithelial cells lining the biliary tree, are the target cells in several liver diseases, termed cholangiopathies. Cholangiopathies are a challenge for clinicians and an enigma for scientists, as the pathogenetic mechanisms by which they develop, and the therapeutic tools for these diseases are still undefined. Several studies demonstrate that many visceral hormones, neuropeptides, and neurotransmitters modulate the adaptive changes of cholangiocytes to chronic cholestatic injury. The aim of this review is to present the recent findings that contributed to clarify the role of visceral hormones and neuropeptides in the regulation of the pathophysiology of cholestasis. These studies helped to shed light on some aspects of cholangiocyte pathophysiology, revealing novel perspectives for the clinical managements of cholangiopathies.

Leptin enhances cholangiocarcinoma cell growth

Cholangiocarcinoma is a strongly aggressive malignancy with a very poor prognosis. Effective therapeutic strategies are lacking because molecular mechanisms regulating cholangiocarcinoma cell growth are unknown. Furthermore, experimental in vivo animal models useful to study the pathophysiologic mechanisms of malignant cholangiocytes are lacking. Leptin, the hormone regulating caloric homeostasis, which is increased in obese patients, stimulates the growth of several cancers, such as hepatocellular carcinoma. The aim of this study was to define if leptin stimulates cholangiocarcinoma growth. We determined the expression of leptin receptors in normal and malignant human cholangiocytes. Effects on intrahepatic cholangiocarcinoma (HuH-28) cell proliferation, migration, and apoptosis of the in vitro exposure to leptin, together with the intracellular pathways, were then studied. Moreover, cholangiocarcinoma was experimentally induced in obese fa/fa Zucker rats, a genetically established animal species with faulty leptin receptors, and in their littermates by chronic feeding with thioacetamide, a potent carcinogen. After 24 weeks, the effect of leptin on cholangiocarcinoma development and growth was assessed. Normal and malignant human cholangiocytes express leptin receptors. Leptin increased the proliferation and the metastatic potential of cholangiocarcinoma cells in vitro through a signal transducers and activators of transcription 3-dependent activation of extracellular signal-regulated kinase 1/2. Leptin increased the growth and migration, and was antiapoptotic for cholangiocarcinoma cells. Moreover, the loss of leptin function reduced the development and the growth of cholangiocarcinoma. The experimental carcinogenesis model induced by thioacetamide administration is a valid and reproducible method to study cholangiocarcinoma pathobiology. Modulation of the leptin-mediated signal could be considered a valid tool for the prevention and treatment of cholangiocarcinoma.

Cholangiocyte injury and ductopenic syndromes

Cholangiopathies are characterized by a predominantly bile duct-directed inflammatory response that leads to bile duct injury and, if the injury is persistent, bile duct loss and the chance of developing bile duct cancer (cholangiocarcinoma). Although the cholangiopathies have broad range of etiologies and pathogenesis (e.g., inherited disorders, autoimmune disorders, infections, drug-induced, ischemia, and unknown etiology), all share the common pathogenetic target-the biliary epithelial cell (cholangiocyte). For the most part, the pathogenesis of these diseases is poorly understood, which correspondingly has restricted clinicians to nonspecific and usually ineffective therapies for these disorders. Nevertheless, significant advances toward the understanding of the mechanisms involved in cholangiocyte-directed inflammation, biliary fibrosis, cholangiocyte death, and cholangiocarcinoma have unfolded over the past 15 years that may provide us new hopes and schemes for treatment of these disorders.

Novel interaction of bile acid and neural signaling in the regulation of cholangiocyte function

Cholangiocytes, the epithelial cells that line the intrahepatic biliary tree, are the target of cholangiopathies, a wide array of chronic disorders that are characterized by the progressive vanishing of bile ducts, leading to ductopenia and liver failure. The loss of bile ducts is a consequence of cholangiocyte death by apoptosis and impaired proliferative response of these cells to injury. The factors that regulate cholangiocyte proliferation and survival are poorly understood. In this regard, a major role is played by the interaction between bile acids and the autonomic nervous system. It has been shown that adrenergic and cholinergic denervation of the liver results in the induction of cell death and impaired proliferative responses of the biliary epithelium to cholestasis. In addition,bile acids have been shown to enter cholangiocytes through the apical, Na(+)-dependent bile acid transporter, ASBT, which has a marked impact on cholangiocyte pathobiology. Recent evidence shows that bile acids and autonomic innervation interact in modulating cholangiocyte response to liver injury. In this review, we describe the recent advances in understanding the molecular mechanisms by which such events occur.

Taurocholic acid feeding prevents tumor necrosis factor-alpha-induced damage of cholangiocytes by a PI3K-mediated pathway

Cholangiopathies, such as primary biliary cirrhosis and primary sclerosis cholangitis, are characterized at the end stage by ductopenia due to increased cholangiocyte apoptosis and decreased cholangiocyte proliferation. Although cholangiocyte proliferation is associated with an increased number of intra-hepatic bile ducts and secretin-stimulated ductal secretion, ductopenia is coupled with decreased ductal mass and secretin-induced ductal secretory activity. We have shown that a single injection of actinomycin D + tumor necrosis factor-alpha (TNF-alpha ) to bile duct-ligated (BDL) rats induces cholangiocyte injury, which is characterized by loss of cholangiocyte proliferation, and secretory activity and by an increase in cholangiocyte apoptosis. We also have shown that taurocholic acid both in vivo and in vitro stimulates cholangiocyte proliferation. We hypothesize that taurocholic acid feeding protects cholangiocytes against TNF-alpha -induced apoptosis through a phosphatidylinositol-3-kinase (PI3K)-dependent pathway. Immediately after BDL, rats were fed taurocholic acid or control diet in the absence/presence of daily injections of wortmannin for 1 week. Seven days later, control-fed or taurocholic acid-fed rats were treated with a single intraperitoneal injection of actinomycin D + TNF-alpha . Twenty-four hours later we evaluated: (i) cholangiocyte apoptosis and proliferation in liver sections and (ii) basal and secretin-stimulated bile and bicarbonate secretion in bile fistula rats. Taurocholic acid feeding prevented TNF-alpha -induced increases in cholangiocyte apoptosis and decreases in growth and secretin-stimulated bile and bicarbonate secretion, changes that were blocked by PI3K inhibition. The PI3K survival pathway is important in bile acid protection against immune-mediated cholangiocyte injury in cholestatic liver diseases.

Cytoprotective effects of taurocholic acid feeding on the biliary tree after adrenergic denervation of the liver

BACKGROUND

Cholangiopathies impair the balance between proliferation and apoptosis of cholangiocytes leading to the disappearance of bile ducts and liver failure. Taurocholic acid (TC) is essential for cholangiocyte proliferative and functional response to cholestasis. Bile acids and neurotransmitters co-operatively regulate the biological response of the biliary epithelium to cholestasis. Adrenergic denervation of the liver during cholestasis results in the damage of bile ducts.

AIM

To verify whether TC feeding prevents the damage of the biliary tree induced by adrenergic denervation in the course of cholestasis.

METHODS

Rats subjected to bile duct ligation (BDL) and to adrenergic denervation were fed a TC-enriched diet, in the absence or presence of daily administration of the phosphatidyl-inositol-3-kinase (PI3K) inhibitor wortmannin for 1 week.

RESULTS

TC prevented the induction of cholangiocyte apoptosis induced by adrenergic denervation. TC also restored cholangiocyte proliferation and functional activity, reduced after adrenergic denervation. TC prevented AKT dephosphorylation induced by adrenergic denervation. The cytoprotective effects of TC were abolished by the simultaneous administration of wortmannin.

SUMMARY/CONCLUSIONS

TC administration prevents the damage of the biliary tree induced by the adrenergic denervation of the liver. These novel findings open novel perspectives in the understanding of the potential of bile acids especially in post-transplant liver disease.

H3 histamine receptor agonist inhibits biliary growth of BDL rats by downregulation of the cAMP-dependent PKA/ERK1/2/ELK-1 pathway

Histamine regulates many functions by binding to four histamine G-coupled receptor proteins (H1R, H2R, H3R and H4R). As H3R exerts their effects by coupling to Galpha(i/o) proteins reducing adenosine 3', 5'-monophosphate (cAMP) levels (a key player in the modulation of cholangiocyte hyperplasia/damage), we evaluated the role of H3R in the regulation of biliary growth. We posed the following questions: (1) Do cholangiocytes express H3R? (2) Does in vivo administration of (R)-(alpha)-(-)-methylhistamine dihydrobromide (RAMH) (H3R agonist), thioperamide maleate (H3R antagonist) or histamine, in the absence/presence of thioperamide maleate, to bile duct ligated (BDL) rats regulate cholangiocyte proliferation? and (3) Does RAMH inhibit cholangiocyte proliferation by downregulation of cAMP-dependent phosphorylation of protein kinase A (PKA)/extracellular signal-regulated kinase 1/2 (ERK1/2)/ets-like gene-1 (Elk-1)? The expression of H3R was evaluated in liver sections by immunohistochemistry and immunofluorescence, and by real-time PCR in cholangiocyte RNA from normal and BDL rats. BDL rats (immediately after BDL) were treated daily with RAMH, thioperamide maleate or histamine in the absence/presence of thioperamide maleate for 1 week. Following in vivo treatment of BDL rats with RAMH for 1 week, and in vitro stimulation of BDL cholangiocytes with RAMH, we evaluated cholangiocyte proliferation, cAMP levels and PKA, ERK1/2 and Elk-1 phosphorylation. Cholangiocytes from normal and BDL rats express H3R. The expression of H3R mRNA increased in BDL compared to normal cholangiocytes. Histamine decreased cholangiocyte growth of BDL rats to a lower extent than that observed in BDL RAMH-treated rats; histamine-induced inhibition of cholangiocyte growth was partly blocked by thioperamide maleate. In BDL rats treated with thioperamide maleate, cholangiocyte hyperplasia was slightly higher than that of BDL rats. In vitro, RAMH inhibited the proliferation of BDL cholangiocytes. RAMH inhibition of cholangiocyte growth was associated with decreased cAMP levels and PKA/ERK1/2/Elk-1 phosphorylation. Downregulation of cAMP-dependent PKA/ERK1/2/Elk-1 phosphorylation (by activation of H3R) is important in the inhibition of cholangiocyte growth in liver diseases.

Thyroid hormone inhibits biliary growth in bile duct-ligated rats by PLC/IP(3)/Ca(2+)-dependent downregulation of SRC/ERK1/2

The role of the thyroid hormone agonist 3,3',5 l-tri-iodothyronine (T3) on cholangiocytes is unknown. We evaluated the in vivo and in vitro effects of T3 on cholangiocyte proliferation of bile duct-ligated (BDL) rats. We assessed the expression of alpha(1)-, alpha(2)-, beta(1)-, and beta(2)-thyroid hormone receptors (THRs) by immunohistochemistry in liver sections from normal and BDL rats. BDL rats were treated with T3 (38.4 mug/day) or vehicle for 1 wk. We evaluated 1) biliary mass and apoptosis in liver sections and 2) proliferation in cholangiocytes. Serum-free T3 levels were measured by chemiluminescence. Purified BDL cholangiocytes were treated with 0.2% BSA or T3 (1 muM) in the absence/presence of U-73122 (PLC inhibitor) or BAPTA/AM (intracellular Ca(2+) chelator) before measurement of PCNA protein expression by immunoblots. The in vitro effects of T3 (1 muM) on 1) cAMP, IP(3), and Ca(2+) levels and 2) the phosphorylation of Src Tyr139 and Tyr530 (that, together, regulate Src activity) and ERK1/2 of BDL cholangiocytes were also evaluated. alpha(1)-, alpha(2)-, beta(1)-, and beta(2)-THRs were expressed by bile ducts of normal and BDL rats. In vivo, T3 decreased cholangiocyte proliferation of BDL rats. In vitro, T3 inhibition of PCNA protein expression was blocked by U-73122 and BAPTA/AM. Furthermore, T3 1) increased IP(3) and Ca(2+) levels and 2) decreased Src and ERK1/2 phosphorylation of BDL cholangiocytes. T3 inhibits cholangiocyte proliferation of BDL rats by PLC/IP(3)/Ca(2+)-dependent decreased phosphorylation of Src/ERK1/2. Activation of the intracellular signals triggered by T3 may modulate the excess of cholangiocyte proliferation in liver diseases.

Molecular pathology of biliary tract cancers

The molecular mechanisms underlying the development, growth and metastatic diffusion of biliary tract cancers are still undefined. The increase in worldwide incidence and mortality of cholangiocarcinoma justifies the impellent need to clarify the intracellular mechanisms triggering the malignant transformation of the biliary epithelium and growth of biliary malignancies. A more complete characterization of the molecular pathology of bile duct cancers could lead to the identification of valid targets for the diagnosis and therapy of these devastating malignancies. This review describes the scientific progress made over the past decades with regard to the understanding of the molecular processes of cholangiocarcinogenesis.

Administration of r-VEGF-A prevents hepatic artery ligation-induced bile duct damage in bile duct ligated rats

The hepatic artery, through the peribiliary plexus, nourishes the intrahepatic biliary tree. During obstructive cholestasis, the nutritional demands of intrahepatic bile ducts are increased as a consequence of enhanced proliferation; in fact, the peribiliary plexus (PBP) displays adaptive expansion. The effects of hepatic artery ligation (HAL) on cholangiocyte functions during cholestasis are unknown, although ischemic lesions of the biliary tree complicate the course of transplanted livers and are encountered in cholangiopathies. We evaluated the effects of HAL on cholangiocyte functions in experimental cholestasis induced by bile duct ligation (BDL). By using BDL and BDL + HAL rats or BDL + HAL rats treated with recombinant-vascular endothelial growth factor-A (r-VEGF-A) for 1 wk, we evaluated liver morphology, the degree of portal inflammation and periductular fibrosis, microcirculation, cholangiocyte apoptosis, proliferation, and secretion. Microcirculation was evaluated using a scanning electron microscopy vascular corrosion cast technique. HAL induced in BDL rats 1) the disappearance of the PBP, 2) increased apoptosis and impaired cholangiocyte proliferation and secretin-stimulated ductal secretion, and 3) decreased cholangiocyte VEGF secretion. The effects of HAL on the PBP and cholangiocyte functions were prevented by r-VEGF-A, which, by maintaining the integrity of the PBP and cholangiocyte proliferation, prevents damage of bile ducts following ischemic injury.

Nervous and Neuroendocrine regulation of the pathophysiology of cholestasis and of biliary carcinogenesis

Cholangiocytes, the epithelial cells lining the biliary ducts, are the target cells in several liver diseases. Cholangiopathies and cholangiocarcinoma generate interest in many scientists since the genesis. The developing mechanisms, and the therapeutic tools of these diseases are still undefined. Several studies demonstrate that many hormones, neuropeptides and neurotransmitters regulate malignant and non-malignant cholangiocyte pathophysiology in the course of chronic biliary diseases. The aim of this review is to present the findings of several studies published in the recent years that contributed to clarifying the role of nervous and neuroendocrine regulation of the pathophysiologic events associated with cholestasis and cholangiocarcinoma development. This manuscript is organized into two parts. The first part offers an overview of the innervation of the liver and the origin of neuroendocrine hormones, neurotransmitters and neuropeptides affecting cholangiocyte function and metabolism. The first section also reviews the effects played by several neuroendocrine hormones and nervous system on cholangiocyte growth, survival and functional activity in the course of cholestasis. In the second section, we summarize the results of some studies describing the role of nervous system and neuroendocrine hormones in the regulation of malignant cholangiocyte growth.

Heterogeneity of the intrahepatic biliary epithelium

The objectives of this review are to outline the recent findings related to the morphological heterogeneity of the biliary epithelium and the heterogeneous pathophysiological responses of different sized bile ducts to liver gastrointestinal hormones and peptides and liver injury/toxins with changes in apoptotic, proliferative and secretory activities. The knowledge of biliary function is rapidly increasing because of the recognition that biliary epithelial cells (cholangiocytes) are the targets of human cholangiopathies, which are characterized by proliferation/damage of bile ducts within a small range of sizes. The unique anatomy, morphology, innervation and vascularization of the biliary epithelium are consistent with function of cholangiocytes within different regions of the biliary tree. The in vivo models [e.g., bile duct ligation (BDL), partial hepatectomy, feeding of bile acids, carbon tetrachloride (CCl₄) or α-naphthylisothiocyanate (ANIT)] and the in vivo experimental tools [e.g., freshly isolated small and large cholangiocytes or intrahepatic bile duct units (IBDU) and primary cultures of small and large murine cholangiocytes] have allowed us to demonstrate the morphological and functional heterogeneity of the intrahepatic biliary epithelium. These models demonstrated the differential secretory activities and the heterogeneous apoptotic and proliferative responses of different sized ducts. Similar to animal models of cholangiocyte proliferation/injury restricted to specific sized ducts, in human liver diseases bile duct damage predominates specific sized bile ducts. Future studies related to the functional heterogeneity of the intrahepatic biliary epithelium may disclose new pathophysiological treatments for patients with cholangiopathies.

Endogenous opioids modulate the growth of the biliary tree in the course of cholestasis

BACKGROUND & AIMS

There is poor knowledge on the factors that modulate the growth of cholangiocytes, the epithelial cell target of cholangiopathies, which are diseases leading to progressive loss of bile ducts and liver failure. Endogenous opioids are known to modulate cell growth. In the course of cholestasis, the opioidergic system is hyperactive, and in cholangiocytes a higher expression of opioid peptide messenger RNA has been described. This study aimed to verify if such events affect the cholangiocyte proliferative response to cholestasis.

METHODS

The presence of the delta opioid receptor (OR), muOR, and kappaOR was evaluated. The effects on cholangiocyte proliferation of the in vitro and in vivo exposure to their selective agonists, together with the intracellular signals, were then studied. The effects of the OR antagonist naloxone on cell growth were also tested both in vivo and in vitro.

RESULTS

Cholangiocytes express all 3 receptors studied. deltaOR activation strongly diminished the proliferative and functional response of cholangiocytes to cholestasis, whereas muOR resulted in a slight increase in cell growth. The deltaOR signal is mediated by the IP3/CamKIIalpha/PKCalpha pathway, which inhibits the cAMP/PKA/ERK1/2/AKT cascade. In contrast, muOR activation stimulates the cAMP/PKA/ERK1/2/AKT cascade but does not affect the IP3/CamKIIalpha/PKCalpha pathway. The blockage of endogenous opioid peptides by naloxone further enhanced cholangiocyte growth both in vivo and in vitro.

CONCLUSIONS

The increase in opioid peptide synthesis in the course of cholestasis aims to limit the excessive growth of the biliary tree in the course of cholestasis by the interaction with the deltaOR expressed by cholangiocytes.

Vascular endothelial growth factor stimulates rat cholangiocyte proliferation via an autocrine mechanism

BACKGROUND & AIMS

Vascular endothelial growth factor (VEGF) is secreted by several epithelia and modulates cellular functions by autocrine and paracrine mechanisms. The role of VEGF in cholangiocyte pathophysiology is unknown. We evaluated the role of VEGF in the regulation of cholangiocyte proliferation in rats that underwent bile duct ligation.

METHODS

The expression of VEGF-A and VEGF-C and their receptors in cholangiocytes from normal and BDL rats was evaluated. Normal or BDL rats were treated with recombinant-VEGF-A or recombinant-VEGF-C or anti-VEGF antibodies, and proliferation of cholangiocytes was evaluated in situ by morphometry and in vitro by proliferating cell nuclear antigen immunoblots and MTS assay. In vitro, normal rat cholangiocyte cultures were stimulated with r-VEGF-A or r-VEGF-C and proliferation and signal transduction were evaluated.

RESULTS

We found that (1) cholangiocytes express messenger RNA and protein for VEGF-A, VEGF-C, VEGF receptor 2 (VEGFR-2), and VEGF receptor 3 (VEGFR-3) and secrete VEGF; (2) secretion of VEGF and expression of VEGFR-2 and VEGFR-3 increases in BDL cholangiocytes; (3) blocking VEGF in vivo by anti-VEGF-A or anti-VEGF-C antibodies decreases cholangiocyte proliferation; (4) the in vivo administration of r-VEGF-A or r-VEGF-C induces cholangiocyte proliferation in normal rats; and (5) in vitro, VEGF-A increases normal rat cholangiocyte culture proliferation by activation of inositol 1,4,5-triphosphate/Ca2+/protein kinase C alpha and phosphorylation of Src/ERK1/2.

CONCLUSIONS

Cholangiocytes secrete VEGF and express VEGFR-2 and VEGFR-3, all of which are amplified in BDL cholangiocytes. VEGF induces cholangiocyte proliferation by activation of inositol 1,4,5-triphosphate/[Ca2+]i/protein kinase C alpha and phosphorylation of Src/ERK1/2. VEGF mediates the adaptive proliferative response of cholangiocytes to cholestasis.

Adrenergic receptor agonists prevent bile duct injury induced by adrenergic denervation by increased cAMP levels and activation of Akt

Loss of parasympathetic innervation after vagotomy impairs cholangiocyte proliferation, which is associated with depressed cAMP levels, impaired ductal secretion, and enhanced apoptosis. Agonists that elevate cAMP levels prevent cholangiocyte apoptosis and restore cholangiocyte proliferation and ductal secretion. No information exists regarding the role of adrenergic innervation in the regulation of cholangiocyte function. In the present studies, we investigated the role of adrenergic innervation on cholangiocyte proliferative and secretory responses to bile duct ligation (BDL). Adrenergic denervation by treatment with 6-hydroxydopamine (6-OHDA) during BDL decreased cholangiocyte proliferation and secretin-stimulated ductal secretion with concomitant increased apoptosis, which was associated with depressed cholangiocyte cAMP levels. Chronic administration of forskolin (an adenylyl cyclase activator) or beta(1)- and beta(2)-adrenergic receptor agonists (clenbuterol or dobutamine) prevented the decrease in cholangiocyte cAMP levels, maintained cholangiocyte secretory and proliferative activities, and decreased cholangiocyte apoptosis resulting from adrenergic denervation. This was associated with enhanced phosphorylation of Akt. The protective effects of clenbuterol, dobutamine, and forskolin on 6-OHDA-induced changes in cholangiocyte apoptosis and proliferation were partially blocked by chronic in vivo administration of wortmannin. In conclusion, we propose that adrenergic innervation plays a role in the regulation of biliary mass and cholangiocyte functions during BDL by modulating intracellular cAMP levels.

Ca2+-dependent cytoprotective effects of ursodeoxycholic and tauroursodeoxycholic acid on the biliary epithelium in a rat model of cholestasis and loss of bile ducts

Chronic cholestatic liver diseases are characterized by impaired balance between proliferation and death of cholangiocytes, as well as vanishing of bile ducts and liver failure. Ursodeoxycholic acid (UDCA) is a bile acid widely used for the therapy of cholangiopathies. However, little is known of the cytoprotective effects of UDCA on cholangiocytes. Therefore, UDCA and its taurine conjugate tauroursodeoxycholic acid (TUDCA) were administered in vivo to rats simultaneously subjected to bile duct ligation and vagotomy, a model that induces cholestasis and loss of bile ducts by apoptosis of cholangiocytes. Because these two bile acids act through Ca2+ signaling, animals were also treated with BAPTA/AM (an intracellular Ca2+ chelator) or Gö6976 (a Ca2+-dependent protein kinase C-alpha inhibitor). The administration of UDCA or TUDCA prevented the induction of apoptosis and the loss of proliferative and functional responses observed in the bile duct ligation-vagotomized rats. These effects were neutralized by the simultaneous administration of BAPTA/AM or Gö6976. UDCA and TUDCA enhanced intracellular Ca2+ and IP3 levels, together with increased phosphorylation of protein kinase C-alpha. Parallel changes were observed regarding the activation of the MAPK and PI3K pathways, changes that were abolished by addition of BAPTA/AM or Gö6976. These studies provide information that may improve the response of cholangiopathies to medical therapy.

gamma-Aminobutyric acid inhibits cholangiocarcinoma growth by cyclic AMP-dependent regulation of the protein kinase A/extracellular signal-regulated kinase 1/2 pathway

We studied the effect of the inhibitory neurotransmitter, gamma-aminobutyric acid (GABA), in the regulation of cholangiocarcinoma growth. We determined the in vitro effect of GABA on the proliferation of the cholangiocarcinoma cell lines (Mz-ChA-1, HuH-28, and TFK-1) and evaluated the intracellular pathways involved. The effect of GABA on migration of Mz-ChA-1 cells was also evaluated. In vivo, Mz-ChA-1 cells were s.c. injected in athymic mice, and the effects of GABA on tumor size, tumor cell proliferation, apoptosis, collagen quantity, and the expression of vascular endothelial growth factor-A (VEGF-A) and VEGF-C (cancer growth regulators) were measured after 82 days. GABA decreased in vitro cholangiocarcinoma growth in a time-dependent and dose-dependent manner, by both cyclic AMP/protein kinase A- and D-myo-inositol-1,4,5-thriphosphate/Ca(2+)-dependent pathways, leading to down-regulation of extracellular signal-regulated kinase 1/2 phosphorylation. Blocking of GABA(A), GABA(B), and GABA(C) receptors prevented GABA inhibition of cholangiocarcinoma proliferation. GABA inhibited Mz-ChA-1 cell migration and, in vivo, significantly decreased tumor volume, tumor cell proliferation, and VEGF-A/C expression whereas increasing apoptosis compared with controls. An increase in collagen was evident in GABA-treated tumors. GABA decreases biliary cancer proliferation and reduces the metastatic potential of cholangiocarcinoma. GABA may represent a therapeutic agent for patients affected by malignancies of the biliary tract.