A remarkable presentation of a massive Budd-Chiari syndrome

A 59-year-old female presented to the emergency department with malaise, significant weight loss, abdominal discomfort, dyspnoea and severely swollen peripheral extremities. She had a past medical history of sickle cell anaemia, a latent tuberculosis infection and a chronic hepatitis B that was treated with PEG-interferon alpha-2 in 2008. Since 2018, she was lost to follow-up. The patient was critically ill, sarcopenic and lethargic. Clinical examination revealed icteric sclerae and a markedly distended and diffusely tender abdomen and peripheral oedemas. Her vital signs included a blood pressure of 105/64 mmHg, tachycardia of 130 bpm, hypothermia of 35.6°C and a SpO2 of 100% in ambient air. Laboratory workup demonstrated a total bilirubin of 12.9 mg/dL, AST 500 U/L, ALT 218 U/L, ALP 178 U/L and GGT 126 U/L, a thrombocytopenia of 34 x10E3/ μL, 16,01 x10E3/μL leukocytes, a CRP of 94.8 mg/L and a lactate of 10,12 mmol/L. The serum creatinine was 1.04 mg/dL, eGFR 54.1 ml/min. The INR was 2.77 and there was a severe hypoalbuminemia (22 g/L). D-dimers were >20 000 ng/ml. The patient presented also with spontaneous hypoglycaemia. A multiphasic contrast-enhanced thoracic and abdominal computed tomography (CT) was performed (figure 1). Given the results of the CT, a 2D echocardiogram was urgently requested (figure 2).

An unusual cause of portal hypertension

A 66-year-old male with a medical history of coronary artery disease presented with nonspecific symptoms of anorexia, lethargy and an increase in abdominal girth. He was diagnosed 3 months ago with chronic liver disease of undetermined aetiology. He did not smoke and was a social drinker till 4 months ago. He was taking tests showed progressive cholestatic liver enzymes (total bilirubin 1,09 mg/dL, AST 130 U/L, ALT 129 U/L, GGT 517 U/L and ALP 641 U/L) and a severe hypoalbuminemia. Laboratory workup made a metabolic, autoimmune, and viral aetiology of the suspected cirrhosis less probable. Urinalysis showed a rapidly progressive proteinuria in the nephrotic range accompanied by the presence of serum spike of monoclonal lambda light Furosemide, Aldactone, Pantoprazole, Acetylcysteine and Atorvastatin. He had no personal or familial history of liver diseases. Physical examination revealed a tender but distended abdomen and large ascites was present. The laboratory chain protein on electrophoresis with immunofixation. Doppler echocardiography revealed a hypertrophic cardiomyopathy based on diffuse left and right ventricular hypertrophy with relative apical sparing. A diagnostic paracentesis was undertaken and the results were consistent with portal hypertension (SAAG 1,6 g/ dL). Considering the concomitant presence of hypertrophic cardiomyopathy, nephrotic syndrome and a presentation of portal hypertension of undetermined aetiology in presence of a monoclonal IgG lambda light chain spike, a transjugular liver biopsy (figure 1 and 2) was performed with HVPG measurement consistent with significant portal hypertension (15 mmHg).

Liver health and the interplay between obesity, alcohol and bariatric surgery

The prevalence of obesity and metabolic consequences, including non-alcoholic fatty liver disease (NAFLD) has become a global health problem. Obesity has an important impact on chronic liver disease even beyond NAFLD, as it accelerates the progression of alcohol liver disease. Conversely, even moderate alcohol use can affect NAFLD disease severity. Weight loss is the gold standard treatment but adherence to lifestyle changes is very low in the clinical setting. Bariatric surgery can improve metabolic components and cause long-term weight loss. Therefore, bariatric surgery could serve as an attractive treatment option for NAFLD patients. A pitfall is the use of alcohol after bariatric surgery. This short review integrates data about the influence of obesity and alcohol on liver function and the role of bariatric surgery.

Angiogenesis in the progression of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the most prevalent liver disease worldwide, and an increasing cause of liver cirrhosis and hepatocellular carcinoma. Angiogenesis, the formation of new blood vessels from pre-existing ones, is a key pathophysiological mechanism contributing to NAFLD progression. Major triggers for angiogenesis in NAFLD include tissue hypoxia, structural and dynamic endothelial cell dysfunction, stellate cell activation and macrophage-mediated inflammation. In turn, angiogenesis drives inflammation and is closely linked to the progression of liver fibrosis and the development of liver cancer. In particular, the molecular crosstalk between pro-angiogenic endothelial cells and activated stellate cells can result in a positive feedback loop in which angiogenesis and fibrosis develop in parallel. In this review, we highlight the molecular mechanisms, drivers and consequences of angiogenesis in the progression of NAFLD to NASH, fibrosis and hepatocellular carcinoma. Evidence from animal and clinical studies suggests that mediators of angiogenesis and endothelial dysfunction are promising disease biomarkers, and that inhibiting angiogenesis may improve the course of NAFLD.

Update on liver transplantation for cholangiocarcinoma : a review of the recent literature

Cholangiocarcinoma (CC) represent 3% of all gastrointestinal tumours and can be classified anatomically in 3 types: intrahepatic (ICC), perihilar (PCC) and distal (DCC) cholangiocarcinomas. Resection is the treatment of choice but is only achieved in a few cases (<20%) because of invasion of the biliary tract and/or vascular structures. The outcome of advanced CC is poor with an overall survival (OS) of maximum 15 months with chemotherapy. In the 1990s, CC was regarded as a contraindication for liver transplantation (LT). LT has recently been proposed as potentially curative option for ICC and PCC. Careful patient selection has changed OS. This article provides an update on current status of LT for patients with unresectable CC.

The potential of glycomics as prognostic biomarkers in liver disease and liver transplantation

The study of glycomics is a novel and fascinating approach for the development of biomarkers. It has become clear that in the field of liver disease specific glycomic patters are present in specific disease states, which has led to the development of diagnostic biomarkers. In this manuscript, we will describe two new applications of this technology for the development of prognostic biomarkers. The first biomarker is associated with the risk of hepatocellular carcinoma development in patients with compensated cirrhosis. The second biomarker is present in perfusate and is related to the risk of primary non function occurrence after liver transplantation. The technology used for these biomarkers could easily be implemented on routine capillary electrophoresis equipment.

The Belgian Association for Study of the Liver Guidance Document on the Management of Adult and Paediatric Non-Alcoholic Fatty Liver Disease

Non-Alcoholic Fatty Liver Disease (NAFLD) is highly prevalent and associated with considerable liver-related and non-liverrelated morbidity and mortality. There is, however, a lot of uncertainty on how to handle NAFLD in clinical practice. The current guidance document, compiled under the aegis of the Belgian Association for the Study of the Liver by a panel of experts in NAFLD, from a broad range of different specialties, covers many questions encountered in daily clinical practice regarding diagnosis, screening, therapy and follow-up in adult and paediatric patients. Guidance statements in this document are based on the available evidence whenever possible. In case of absence of evidence or inconsistency of the data, guidance statements were formulated based on consensus of the expert panel. This guidance document is intended as a help for clinicians (general practitioners and all involved specialties) to implement the most recent evidence and insights in the field of NAFLD within a Belgian perspective.

Phosphodiesterase 2 Protects Against Catecholamine-Induced Arrhythmia and Preserves Contractile Function After Myocardial Infarction

Rationale:

Phosphodiesterase 2 is a dual substrate esterase, which has the unique property to be stimulated by cGMP, but primarily hydrolyzes cAMP. Myocardial phosphodiesterase 2 is upregulated in human heart failure, but its role in the heart is unknown.

Objective:

To explore the role of phosphodiesterase 2 in cardiac function, propensity to arrhythmia, and myocardial infarction.

Methods and Results:

Pharmacological inhibition of phosphodiesterase 2 (BAY 60–7550, BAY) led to a significant positive chronotropic effect on top of maximal β-adrenoceptor activation in healthy mice. Under pathological conditions induced by chronic catecholamine infusions, BAY reversed both the attenuated β-adrenoceptor–mediated inotropy and chronotropy. Conversely, ECG telemetry in heart-specific phosphodiesterase 2-transgenic (TG) mice showed a marked reduction in resting and in maximal heart rate, whereas cardiac output was completely preserved because of greater cardiac contraction. This well-tolerated phenotype persisted in elderly TG with no indications of cardiac pathology or premature death. During arrhythmia provocation induced by catecholamine injections, TG animals were resistant to triggered ventricular arrhythmias. Accordingly, Ca 2+ -spark analysis in isolated TG cardiomyocytes revealed remarkably reduced Ca 2+ leakage and lower basal phosphorylation levels of Ca 2+ -cycling proteins including ryanodine receptor type 2. Moreover, TG demonstrated improved cardiac function after myocardial infarction.

Conclusions:

Endogenous phosphodiesterase 2 contributes to heart rate regulation. Greater phosphodiesterase 2 abundance protects against arrhythmias and improves contraction force after severe ischemic insult. Activating myocardial phosphodiesterase 2 may, thus, represent a novel intracellular antiadrenergic therapeutic strategy protecting the heart from arrhythmia and contractile dysfunction.

Elafibranor, an Agonist of the Peroxisome Proliferator-Activated Receptor-α and -δ, Induces Resolution of Nonalcoholic Steatohepatitis Without Fibrosis Worsening

BACKGROUND & AIMS

Elafibranor is an agonist of the peroxisome proliferator-activated receptor-α and peroxisome proliferator-activated receptor-δ. Elafibranor improves insulin sensitivity, glucose homeostasis, and lipid metabolism and reduces inflammation. We assessed the safety and efficacy of elafibranor in an international, randomized, double-blind placebo-controlled trial of patients with nonalcoholic steatohepatitis (NASH).

METHODS

Patients with NASH without cirrhosis were randomly assigned to groups given elafibranor 80 mg (n = 93), elafibranor 120 mg (n = 91), or placebo (n = 92) each day for 52 weeks at sites in Europe and the United States. Clinical and laboratory evaluations were performed every 2 months during this 1-year period. Liver biopsies were then collected and patients were assessed 3 months later. The primary outcome was resolution of NASH without fibrosis worsening, using protocol-defined and modified definitions. Data from the groups given the different doses of elafibranor were compared with those from the placebo group using step-down logistic regression, adjusting for baseline nonalcoholic fatty liver disease activity score.

RESULTS

In intention-to-treat analysis, there was no significant difference between the elafibranor and placebo groups in the protocol-defined primary outcome. However, NASH resolved without fibrosis worsening in a higher proportion of patients in the 120-mg elafibranor group vs the placebo group (19% vs 12%; odds ratio = 2.31; 95% confidence interval: 1.02-5.24; P = .045), based on a post-hoc analysis for the modified definition. In post-hoc analyses of patients with nonalcoholic fatty liver disease activity score ≥4 (n = 234), elafibranor 120 mg resolved NASH in larger proportions of patients than placebo based on the protocol definition (20% vs 11%; odds ratio = 3.16; 95% confidence interval: 1.22-8.13; P = .018) and the modified definitions (19% vs 9%; odds ratio = 3.52; 95% confidence interval: 1.32-9.40; P = .013). Patients with NASH resolution after receiving elafibranor 120 mg had reduced liver fibrosis stages compared with those without NASH resolution (mean reduction of 0.65 ± 0.61 in responders for the primary outcome vs an increase of 0.10 ± 0.98 in nonresponders; P < .001). Liver enzymes, lipids, glucose profiles, and markers of systemic inflammation were significantly reduced in the elafibranor 120-mg group vs the placebo group. Elafibranor was well tolerated and did not cause weight gain or cardiac events, but did produce a mild, reversible increase in serum creatinine (effect size vs placebo: increase of 4.31 ± 1.19 μmol/L; P < .001).

CONCLUSIONS

A post-hoc analysis of data from trial of patients with NASH showed that elafibranor (120 mg/d for 1 year) resolved NASH without fibrosis worsening, based on a modified definition, in the intention-to-treat analysis and in patients with moderate or severe NASH. However, the predefined end point was not met in the intention to treat population. Elafibranor was well tolerated and improved patients' cardiometabolic risk profile. ClinicalTrials.gov number: NCT01694849.

Luteinizing Hormone Causes Phosphorylation and Activation of the cGMP Phosphodiesterase PDE5 in Rat Ovarian Follicles, Contributing, Together with PDE1 Activity, to the Resumption of Meiosis

The meiotic cell cycle of mammalian oocytes in preovulatory follicles is held in prophase arrest by diffusion of cGMP from the surrounding granulosa cells into the oocyte. Luteinizing hormone (LH) then releases meiotic arrest by lowering cGMP in the granulosa cells. The LH-induced reduction of cGMP is caused in part by a decrease in guanylyl cyclase activity, but the observation that the cGMP phosphodiesterase PDE5 is phosphorylated during LH signaling suggests that an increase in PDE5 activity could also contribute. To investigate this idea, we measured cGMP-hydrolytic activity in rat ovarian follicles. Basal activity was due primarily to PDE1A and PDE5, and LH increased PDE5 activity. The increase in PDE5 activity was accompanied by phosphorylation of PDE5 at serine 92, a protein kinase A/G consensus site. Both the phosphorylation and the increase in activity were promoted by elevating cAMP and opposed by inhibiting protein kinase A, supporting the hypothesis that LH activates PDE5 by stimulating its phosphorylation by protein kinase A. Inhibition of PDE5 activity partially suppressed LH-induced meiotic resumption as indicated by nuclear envelope breakdown, but inhibition of both PDE5 and PDE1 activities was needed to completely inhibit this response. These results show that activities of both PDE5 and PDE1 contribute to the LH-induced resumption of meiosis in rat oocytes, and that phosphorylation and activation of PDE5 is a regulatory mechanism.

Game Maturity Model for Health Care

This article introduces the Game Maturity Model for the healthcare industry as an extension to the general Game Maturity Model and describes the usage by two case studies of applied health games. The Game Maturity Model for healthcare provides a practical and value-adding method to assess existing games and to determine strategic considerations for application of applied health games. Our forecast is that within 5 years the use and development of applied games will have a role in our daily lives and the way we organize health care that will be similar to the role social media has today.

Association of recently described adipokines with liver histology in biopsy-proven non-alcoholic fatty liver disease: a systematic review

The prevalence of non-alcoholic fatty liver disease (NAFLD) is rising, as is the prevalence of obesity and type 2 diabetes. It is increasingly recognized that an impaired pattern in adipokine secretion could play a pivotal role in the development of NAFLD. We performed a systematic review to evaluate the potential link between newly described adipokines and liver histology in biopsy-proven NAFLD patients. A computerized literature search was performed in PubMed, EMBASE and Web of Science electronic databases. Thirty-one cross-sectional studies were included, resulting in a total of seven different investigated adipokines. Studies included in this review mainly had a good methodological quality. Most adipokines were suggested to be involved in the inflammatory response that develops within the context of NAFLD, either at hepatic or systemic level, and/or hepatic insulin resistance. Based on literature, clinical studies suggest that chemerin, resistin and adipocyte-fatty-acid-binding protein potentially are involved in NAFLD pathogenesis and/or progression. However, major inconsistency still exists, and there is a high need for larger studies, together with the need of standardized assays to determine adipokine levels.

IgG4-related cholangitis: Case report and literature review

CASE PRESENTATION

We describe a case of a patient who presents with jaundice, elevated cholestatic liver enzymes, an extreme weight loss and a midcholedochal stricture very suspect for a cholangiocarcinoma. In the conviction of malignancy, although the absence of anatomopathological prove, the patient underwent a choledochal resection. The anatomopathological specimen revealed no malignancy. In the year following resection, the patient keeps presenting with bile duct strictures and further weight loss. Ultimately the diagnosis of Ig G4-related cholangitis is withheld. Therapy with corticosteroids is initiated with a spectacular clinical, biochemical and radiographical result.

DISCUSSION

IgG4-related cholangitis is the biliary presentation of IgG4-related disease, a recently discovered entity of fibroinflammatory masses which can affect virtually every organ in the body. It is characterized by a dense lymphoplasmacytic infiltrate, storiform fibrosis, obliterative phlebitis and a presence of > 30 IgG4-positive plasma cells per high power field. Main differential diagnosis contains cholangiocarcinoma and primary sclerosing cholangitis. Corticoids are cornerstone of therapy, with azathioprine frequently used as a maintenance in case of relapse.

CONCLUSIONS

With this case we want to draw the attention to a rather uncommon cause of biliary obstruction, easily mistaken for a cholangiocarcinoma.

Dephosphorylation and inactivation of NPR2 guanylyl cyclase in granulosa cells contributes to the LH-induced decrease in cGMP that causes resumption of meiosis in rat oocytes

In mammals, the meiotic cell cycle of oocytes starts during embryogenesis and then pauses. Much later, in preparation for fertilization, oocytes within preovulatory follicles resume meiosis in response to luteinizing hormone (LH). Before LH stimulation, the arrest is maintained by diffusion of cyclic (c)GMP into the oocyte from the surrounding granulosa cells, where it is produced by the guanylyl cyclase natriuretic peptide receptor 2 (NPR2). LH rapidly reduces the production of cGMP, but how this occurs is unknown. Here, using rat follicles, we show that within 10 min, LH signaling causes dephosphorylation and inactivation of NPR2 through a process that requires the activity of phosphoprotein phosphatase (PPP)-family members. The rapid dephosphorylation of NPR2 is accompanied by a rapid phosphorylation of the cGMP phosphodiesterase PDE5, an enzyme whose activity is increased upon phosphorylation. Later, levels of the NPR2 agonist C-type natriuretic peptide decrease in the follicle, and these sequential events contribute to the decrease in cGMP that causes meiosis to resume in the oocyte.

Cutaneous infection by Alternaria infectoria in a liver transplant recipient: a case report

We report the case of a 65-year-old man who developed multiple crusty ulcerative skin lesions on both lower extremities six months after liver transplantation. The causative pathogen was identified as Alternaria Infectoria, an opportunistic fungal agent. The patient was successfully treated with fluconazole for 27 weeks, with complete regression of the lesions. Due to the lack of well-designed clinical studies it is difficult to determine the best treatment course regarding solid organ transplant recipients presenting with invasive fungal infections. And for now, the clinician must lean upon case-reports or retrospective analyses to compose the most suited therapy for his patient. Based upon literature, it seems that the combination of a broad spectrum azole and reducing the dose of immunosuppressive drugs is the cornerstone of treating invasive fungal infections in solid organ transplant patients.

Characterization of the cellular activity of PDE 4 inhibitors using two novel PDE 4 reporter cell lines

We report here the generation and pharmacological characterization of two novel PDE 4B1 and PDE 4D3 reporter cell lines. Intracellular cAMP levels are monitored in these cells by a cAMP-sensitive biosensor. We used the recombinant PDE 4B1 and PDE 4D3 reporter cell lines to characterize the cellular effects of various competitive and allosteric PDE 4 inhibitors. In addition, we compared the cellular activity of these PDE 4 inhibitors with the in vitro inhibition of full-length PDE 4D3 and a truncated enzyme comprising the PDE 4D3 catalytic domain. Two different groups of PDE 4 inhibitors could be identified. The first group, including competitive inhibitors like roflumilast, cilomilast and piclamilast, shows similar in vitro activity on full-length and truncated PDE 4D3 and comparably low cellular activity. The second group, including the allosteric inhibitors PMNPQ, D159153, and D159404, shows much better inhibition of full-length versus truncated PDE 4D3. In addition, these compounds show high cellular activity. Our data obtained with the prototype PDE 4 inhibitor rolipram show that rolipram has properties intermediate between the two groups. The results imply that these novel PDE 4 reporter cell lines are well-suited for the characterization of the cellular activity of PDE 4 inhibitors and may also support a better understanding of the complex PDE 4 pharmacology.

Invasive aspergillosis in patients with cirrhosis, a case report and review of the last 10 years

BACKGROUND

Untreated invasive aspergillosis (IA) is lethal, yet diagnosis is often delayed. Recognising the risk factors can lead to earlier diagnosis. We present a case of an invasive pulmonary aspergillosis in a patient with cirrhosis, who had been treated with corticosteroids for 2.5 weeks for alcoholic hepatitis. He was successfully treated with liposomal amphotericin B and caspofungin (first in combination, then caspofungin monotherapy).

PURPOSE

To evaluate the role of aspergillosis in cirrhosis.

METHODS

A literature search on aspergillosis in cirrhosis and liver failure patients was conducted in PubMed/Medline (2002-dec 2012), according to pre-set selection criteria.

RESULTS

20 out of 330 articles were retrieved, representing 43 patients with cirrhosis and/or liver failure who had an aspergillosis infection. Most Aspergillus (A.) infections were due to A. fumigatus and the lungs were the most frequent organ involved (42/43). 58% of the patients used steroids and mortality was 53.5%. The most frequent used antifungal was caspofungin.

DISCUSSION

Diagnosis of IA is difficult and there might be a delay in diagnosis since cirrhosis is not recognised as one of the classical risk factors. Mortality was 53.5%, but this is lower than in previous decades. Since voriconazole is hepatotoxic, treatment with caspofungin and/or amphotericin is preferable.

CONCLUSION

Early recognition of aspergillosis in a cirrhosis/liver failure patient is crucial and should prompt direct treatment.

Pathophysiology and management of post resection liver failure

Post resection liver failure (PRLF) is defined by the occurrence of jaundice, coagulopathy and encephalopathy after liver resection. When PRLF is present, it has a high morbidity and mortality. The incidence of PRLF ranges between 0-30%. For having a healthy regeneration of the liver remnant an adequate number of hepatocytes and nonparenchymal cells, a normal functional and regenerative capacity and also a good accommodation of haemodynamic changes without congestion are needed. To avoid the presence of PRLF ongoing parenchymal damage after the liver resection should be avoided. So, ischemia reperfusion injury should be minimalized, infection and sepsis should be treated immediately and small for size syndrome should be avoided.

Progressive familial intrahepatic cholestasis and benign recurrent intrahepatic cholestasis: a review

Progressive familial intrahepatic cholestasis (PFIC) and benign recurrent intrahepatic cholestasis (BRIC) are two rare autosomal recessive disorders, characterized by cholestasis. They are related to mutations in hepatocellular transport system genes involved in bile formation. The differentiation between PFIC and BRIC is based on phenotypic presentation: PFIC is a progressive disease, with evolution to end-stage liver disease. BRIC is characterized by intermittent recurrent cholestatic episodes, with irresistible pruritus, mostly without evident liver damage. Between symptomatic periods, patients are completely asymptomatic. In this article, a short overview of the aetiology, the clinical and diagnostic characteristics and the therapy of both PFIC and BRIC are given.

Pharmacological characterization of receptor guanylyl cyclase reporter cell lines

Receptor guanylyl cyclases are implicated in a growing number of pathophysiologies and, therefore, represent an important target class for drug development. We report here the generation and pharmacological characterization of three particulate guanylyl cyclase (pGC) reporter cell lines. Plasmid constructs encoding the natriuretic peptide receptors GC-A and GC-B, and the heat-stable enterotoxin receptor GC-C, were stably transfected in a parental reporter cell line expressing a cyclic nucleotide-gated (CNG) cation channel, acting as the biosensor for intracellular cGMP. In our reporter cell lines pGC activity can be monitored in living cells in real-time . By using different natural as well as synthetic receptor ligands of the natriuretic and guanylin peptide families, we show that our reporter assay monitors pGC activity with very high sensitivity. In contrast to previous findings, we could detect significant stimulation of GC-A and GC-B by each of the natriuretic peptides ANP, BNP and CNP. In addition, the clearance receptor ligand Cys-ANF(4-18) and the ANP receptor antagonist Arg-ANF(6-18) were characterized as partial GC-A agonists. The results imply that our novel pGC reporter cell lines are well suited for the characterization of receptor pharmacology and may be used for natural ligand characterization of guanylyl cyclase orphan receptors.

Hepatitis E seroprevalence in east and west Flanders, Belgium

BACKGROUND AND STUDY AIM

Hepatitis E virus (HEV) infection is increasingly recognized as a cause of hepatitis in developed countries. The goal of this study is to provide an estimate of the seroprevalence of HEV in Belgium, more precisely in East and West Flanders, since data for this country are currently lacking.

PATIENTS AND METHODS

One hundred patients presenting at the gynecological (mainly fertility center) or orthopedic clinics of our hospital were randomly selected to be tested for anti-HEV IgG antibodies using a sensitive indirect ELISA and, in the case of a borderline result, a strip immunoassay.

RESULTS

The anti-HEV IgG seroprevalence was found to be 14%.

CONCLUSIONS

The observed seroprevalence rate suggests that HEV infection is not an uncommon occurrence in Belgium. Comparisons with published seroprevalence data of other Western European countries should be made with caution due to differences in the analytical performance of anti-HEV IgG assays.

Luteinizing hormone reduces the activity of the NPR2 guanylyl cyclase in mouse ovarian follicles, contributing to the cyclic GMP decrease that promotes resumption of meiosis in oocytes

In preovulatory ovarian follicles of mice, meiotic prophase arrest in the oocyte is maintained by cyclic GMP from the surrounding granulosa cells that diffuses into the oocyte through gap junctions. The cGMP is synthesized in the granulosa cells by the transmembrane guanylyl cyclase natriuretic peptide receptor 2 (NPR2) in response to the agonist C-type natriuretic peptide (CNP). In response to luteinizing hormone (LH), cGMP in the granulosa cells decreases, and as a consequence, oocyte cGMP decreases and meiosis resumes. Here we report that within 20 min, LH treatment results in decreased guanylyl cyclase activity of NPR2, as determined in the presence of a maximally activating concentration of CNP. This occurs by a process that does not reduce the amount of NPR2 protein. We also show that by a slower process, first detected at 2h, LH decreases the amount of CNP available to bind to the receptor. Both of these LH actions contribute to decreasing cGMP in the follicle, thus signaling meiotic resumption in the oocyte.

Ascites: not always the usual suspects

A case report of a 44-year-old woman with an infrequent cause of ascites, i.e. intraperitoneal urine leakage, is presented. Urinary ascites due to spontaneous bladder rupture or fistula after radiation therapy for cervical cancer is not a rare complication and can develop several years after initial treatment. Diagnosis of urinary ascites should be suspected in patients with ascites and a history of radiation therapy for a bladder or a gynaecological disease. Measurement of urea and creatinine levels in urine, ascites and plasma is a simple and non-invasive diagnostic test. In physiological conditions, the ascites/plasma creatinine ratio approximates a ratio of one to one. This ratio is elevated to a value of 5/1 in case of urinary ascites. Although cystoscopy and imaging techniques such as cystography and computed tomography (with or without cystography) are extremely helpful, definitive diagnosis is frequently based on intraoperative findings, because of the lack of pathognomonic symptoms or signs. Surgery is the treatment of choice.

Chemosensory Ca2+ dynamics correlate with diverse behavioral phenotypes in human sperm

In the female reproductive tract, mammalian sperm undergo a regulated sequence of prefusion changes that "prime" sperm for fertilization. Among the least understood of these complex processes are the molecular mechanisms that underlie sperm guidance by environmental chemical cues. A "hard-wired" Ca(2+) signaling strategy that orchestrates specific motility patterns according to given functional requirements is an emerging concept for regulation of sperm swimming behavior. The molecular players involved, the spatiotemporal characteristics of such motility-associated Ca(2+) dynamics, and the relation between a distinct Ca(2+) signaling pattern and a behavioral sperm phenotype, however, remain largely unclear. Here, we report the functional characterization of two human sperm chemoreceptors. Using complementary molecular, physiological, and behavioral approaches, we comparatively describe sperm Ca(2+) responses to specific agonists of these novel receptors and bourgeonal, a known sperm chemoattractant. We further show that individual receptor activation induces specific Ca(2+) signaling patterns with unique spatiotemporal dynamics. These distinct Ca(2+) dynamics are correlated to a set of stimulus-specific stereotyped behavioral responses that could play vital roles during various stages of prefusion sperm-egg chemical communication.

The multicenter Belgian survey on liver transplantation for hepatocellular failure after bariatric surgery

The prevalence of obesity has grown dramatically over the last decades, with nonalcoholic steatohepatitis increasingly observed. Therapeutic options for morbid obesity include bariatric surgery. Fatal liver failure (LF) has been recorded after jejunoileal bypass (JIB) but is controversial after biliopancreatic diversion (BPD, Scopinaro operation). We performed a survey on the frequency of liver transplantation (LT) after bariatric surgery in Belgium. An enquiry was sent to all Belgian liver transplant centers to investigate the occurrence of subacute and chronic LF after bariatric surgery. After weight-reduction surgery, 10 patients in 3 Belgian transplant centers were listed for LT due to severe hepatocellular failure. Nine of them had undergone a Scopinaro operation and 1 a jejunoileal bypass. The median time to develop LF was 5 years. The patient with JIB developed chronic LF after 25 years. Seven patients were transplanted; two died awaiting a graft and one is still on the waiting list. After LT, 1 patient developed rapid reappearance of LF at 10 months, requiring retransplantation. Two recipients died after LT because of multiorgan failure shortly after transplantation. In another case, a de novo cancer was fatal at 6 years' follow-up. The remaining recipients were doing well. According to this survey, the BPD operation carries a potential risk of LF. However, because there were only 10 cases, we remain unaware of the actual incidence of Scopinaro operation-induced LF. We advise strict follow-up of liver function and timely dismantling of BPD.

Early arterial revascularization after hepatic artery thrombosis may avoid graft loss and improve outcomes in adult liver transplantation

BACKGROUND

Hepatic artery thrombosis (HAT) represents a devastating complication after liver transplantation (LT), occurring in 1.6%-9.2% of adult recipients. Treatments of HAT include thrombectomy and thrombolysis (with or without redo of the arterial anastomosis), percutaneous thrombolysis through an angiogram, liver retransplantation, and clinical observation.

METHODS

We retrospectively analyzed data from 739 adult LTs between January 1992 and September 2009. HAT was classified as early (E-HAT), when occurring within the first 30 days after LT, or late HAT (L-HAT), when diagnosed from the 2nd month onward. HAT suspected clinically was confirmed by Doppler ultrasound and angiography in all cases. Attempted revascularization was defined as early (ER) if performed within the first 2 weeks after LT and late (LR) if performed between 15 and 30 days.

RESULTS

After a median follow-up (FU) of 62 months (range, 1-227 months), HAT occurred in 31/739 grafts (4.3%). E-HAT was recorded in 25/31 cases (3.4%) and L-HAT in 11/31 cases (0.8%). ER was performed in 20/31 patients (65%) leading to 62% graft salvage; it was 81% when the revascularization was performed within the first week after LT (P = ns). LR was unsuccessful in all cases (P = .08). The overall incidence of BC among rescued grafts was 54% without graft loss during FU. Graft survival was 79% versus 71%; and 50% versus 50% at 1 and 3 years for E-HAT and L-HAT, respectively (P = ns).

CONCLUSIONS

Urgent revascularization in cases of early HAT may decrease graft loss, especially when performed within the first week after LT, with improved overall outcomes.

TOX3 is a neuronal survival factor that induces transcription depending on the presence of CITED1 or phosphorylated CREB in the transcriptionally active complex

TOX3 is a nuclear protein containing a high mobility group (HMG)-box domain, which regulates Ca(2+)-dependent transcription in neurons through interaction with the cAMP-response-element-binding protein (CREB). TOX3 appears to be associated with breast cancer susceptibility and was previously shown to be expressed downstream of a cytoprotective cascade together with CITED1, a transcriptional regulator that does not bind directly to DNA. In the present study we show that TOX3 is predominantly expressed in the brain, forms homodimers and interacts with CITED1. TOX3 overexpression protects neuronal cells from cell death caused by endoplasmic reticulum stress or BAX overexpression through the induction of anti-apoptotic transcripts and repression of pro-apoptotic transcripts, which correlates with enhanced transcription involving isolated estrogen-responsive elements and estrogen-responsive promoters. However, both functions cannot be inhibited with the anti-estrogen fulvestrant and are only attenuated by mutation of estrogen-responsive elements. TOX3 also interacts with native CREB and induces the CREB-responsive BCL-2 promoter, which can be inhibited by coexpression of CITED1. Coexpression of CREB, by contrast, abolishes TOX3-mediated transcription from the estrogen-responsive complement C3 promoter. Our results suggest that TOX3 can enhance transcriptional activation from different cytoprotective promoters and that this is dependent on the predominance of either phosphorylated CREB or CITED1 within the transcriptionally active complex.

A novel giant peroxisomal superoxide dismutase motif-containing protein

Oxidative glutamate toxicity in the neuronal cell line HT22 is a model for neuronal cell death by oxidative stress. In this model, extracellular glutamate blocks cystine uptake via the glutamate/cystine antiporter system x(c)(), eventually leading to depletion of the antioxidant glutathione and cell death. We used subtractive suppression hybridization and a screening procedure using various HT22 sublines to identify transcripts relevantly upregulated in resistance to oxidative glutamate toxicity. One of these coded for a novel protein of 3440 amino acids comprising a superoxide dismutase (SOD) motif, which we named TIGR for "transcript increased in glutamate resistance." TIGR is mainly expressed in the nervous system in cortical pyramidal and hippocampal neurons. Intracellularly, TIGR colocalizes with catalase, strongly suggesting a peroxisomal localization. Overexpression of TIGR but not of a mutant lacking two conserved histidine residues in the SOD motif increased SOD activity and protected against oxidative stress in mammalian cells, but had no direct SOD activity in yeast. We conclude that this novel giant peroxisomal protein is implicated in resistance to oxidative stress. Despite the presence of a SOD motif, which is necessary for protection in mammalian cells, the protein is not a functional SOD, but might be involved in SOD activity.

Cardiac glycosides potently inhibit C-reactive protein synthesis in human hepatocytes

Elevated plasma levels of C-reactive protein (CRP), the prototype acute-phase protein (APP), are predictive for future cardiovascular events. Controversial evidence suggests that CRP may play a causal role in cardiovascular disease. CRP synthesis inhibition is a potential approach for reducing cardiovascular mortality. We show here that endogenous and plant-derived inhibitors of the Na(+)/K(+)-ATPase, i.e. the cardiac glycosides ouabain and digitoxin, inhibit IL-1beta- and IL-6-induced APP expression in human hepatoma cells and primary human hepatocytes (PHH) at nanomolar concentrations. Inhibition is demonstrated on transcriptional and on protein level. The molecular target of cardiac glycosides, i.e. the alpha1 subunit of the Na(+)/K(+)-ATPase, is strongly expressed in human hepatocytes. Inhibition of APP synthesis correlates with the potency of cardiac glycosides at the Na(+)/K(+)-ATPase. The trigger for APP expression inhibition is an increase in intracellular calcium since the calcium ionophore calcimycin is also active. Qualified specificity of oubain for hepatocellular APP synthesis inhibition is demonstrated by lack of effectivity on IL-1beta-induced IL-6 release from primary human coronary artery smooth muscle cells. The inhibitory activity of cardiac glycosides on CRP expression may have important implications for the treatment of cardiovascular disease. Cardiac glycosides may be used for CRP synthesis inhibition in the future.

Improved results for adult split liver transplantation with extended right lobe grafts: could we enhance its application?

OBJECTIVE

Split liver transplantation (SLT) allows grafting of 2 recipients with 1 allograft. Results of adult SLT have improved since its first introduction. Children benefit most from SLT, while among some adult liver transplanters there are concerns about splitting a liver, turning a good quality graft into a marginal one. We performed a single center retrospective review to address this issue.

PATIENTS AND METHODS

Between June 2001 and August 2008, we performed 22 extended right liver graft (eRLG) transplantations in 21 adult patients.

RESULTS

Eleven donors (50%) did not meet the Eurotransplant criteria for optimal donors. Forty-one percent of eRLG donors showed hemodynamic instability at the time of harvest. Eighteen (82%) splitting procedures were performed ex situ. The main indications for transplantation were alcoholic liver cirrhosis (32%), hepatitis C-related cirrhosis (18%), and acute liver failure (18%). Mean recipient age was 54 years (range, 17-69 years); median Model for End-Stage Liver Disease (MELD) score was 15 (range, 7-40). Patients were followed for a median of 16 months (range, 4-92 months) following transplantation. We observed 5 (23%) vascular and 3 (14%) biliary complications. Overall patient survival was 84% at 3 years; overall graft survival was 79%. For the 11 patients who had undergone transplantation after 2007, we observed a 100% patient and graft survival.

CONCLUSION

After an initial learning curve and provided careful selection, exceptions to classical donor criteria for splitting can be accepted with successful outcomes comparable to those after whole liver transplantation.

An inhibitor of interleukin-6 trans-signalling, sgp130, contributes to impaired acute phase response in human chronic liver disease

In chronic liver disease, high circulating interleukin (IL)-6 contrasts with a poor acute phase response. We evaluated the impact of liver and circulating IL-6-receptor (IL-6R) forms on IL-6 bioactivity in chronic liver disease. IL-6, soluble IL-6-receptor and sgp130 levels were assayed in plasma from 45 patients with alcoholic liver disease, 84 with hepatitis C virus (HCV) infection undergoing transjugular liver biopsies and 15 healthy subjects. IL-6R mRNA was quantified on liver extracts from 54 patients with alcoholic liver disease with or without cirrhosis and 18 HCV-infected patients. The effect of gp130-Fc on fibrinogen secretion induced by IL-6 trans-signalling was evaluated on hepatocyte cultures. Levels of plasma IL-6 and sgp130, but not soluble IL-6R, increased with the stage of chronic liver disease, and correlated significantly with disease severity. Alcoholic liver disease patients had higher plasma IL-6 levels than hepatitis C, but lower liver IL-6R expression. In alcoholic and HCV-related liver diseases, liver IL-6R expression decreased with advanced fibrosis stage. In vitro, on hepatocytes, gp130-Fc blunted the acute phase response while soluble IL-6R enhanced IL-6 stimulation. In advanced chronic liver disease, high plasma IL-6 is associated with low liver IL-6R expression. This situation enables high plasma sgp130 to act as a major negative regulator of liver IL-6 trans-signalling, as demonstrated functionally here on hepatocytes. This might explain the poor acute phase response induced by IL-6 in chronic liver disease.

A novel PDE2A reporter cell line: characterization of the cellular activity of PDE inhibitors

We report here the generation and pharmacological characterization of a phosphodiesterase 2A (PDE2A) reporter cell line. Human PDE2A was stably transfected in a parental cell line expressing the atrial natriuretic peptide (ANP) receptor and the cyclic nucleotide-gated (CNG) cation channel CNGA2, acting as the biosensor for intracellular cGMP. In this reporter cell line, cGMP levels can be monitored in real-time via aequorin luminescence stimulated by calcium influx through the CNG channel. By using different PDE inhibitors, we could show that our PDE2A reporter assay specifically monitors PDE2A inhibition with high sensitivity. In the absence of ANP stimulation, the PDE2A selective inhibitors EHNA, BAY 60-7550 and PDP did not increase basal luminescence levels in this experimental setting. However, in combination with ANP, these inhibitors stimulated luminescence signals and induced leftward shifts of ANP concentration-response curves. Similar results were obtained when using IBMX, trequinsin and dipyridamole, which inhibit PDE2A nonselectively with lower potency. PDP, the most potent PDE2A inhibitor known to date, was found to exhibit much lower cellular activity as anticipated from its biochemical PDE2A inhibitory activity. By cellular uptake and transport studies we could show that PDP's cell permeability is low and that the compound is a substrate for an efflux transporter. Other PDE inhibitors including vinpocetine, milrinone, rolipram, sildenafil, zaprinast, BRL 50481 and BAY 73-6691 did not stimulate luminescence signals on our PDE2A reporter cell line. The results imply that this novel PDE2A reporter assay provides an efficient, high throughput means for the identification and characterization of PDE2A inhibitors.

The constitutively active orphan G-protein-coupled receptor GPR39 protects from cell death by increasing secretion of pigment epithelium-derived growth factor

GPR39 is a constitutively active orphan G-protein-coupled receptor capable of increasing serum response element-mediated transcription. We found GPR39 to be up-regulated in a hippocampal cell line resistant against diverse stimulators of cell death and show that its overexpression protects against oxidative and endoplasmic reticulum stress, as well as against direct activation of the caspase cascade by Bax overexpression. In contrast, silencing GPR39 rendered cells more susceptible to cell death. An array analysis of transcripts induced by GPR39 revealed up-regulation of RGS16 (inhibitor of G-protein signaling 16), which suggested coupling to Galpha(13) and induction of serum response element-mediated transcription by the small GTPase RhoA. In line with this, co-expression of GPR39 with RGS16, dominant-negative RhoA, or serum response factor abolished cell protection, whereas overexpression of the serum response factor protected from cell death. Further downstream the signaling cascade, GPR39 overexpression leads to increased secretion of the cytoprotective pigment epithelium-derived growth factor (PEDF). Medium conditioned by cells overexpressing GPR39 contained 4-fold more PEDF, and when stripped off it lost most but not all of its protective properties. We conclude that GPR39 is a novel inhibitor of cell death, which might represent a therapeutic target with implications for processes involving apoptosis and endoplasmic reticulum stress like cancer, ischemia/reperfusion injury, and neurodegenerative disease.

Pharmacological and kinetic characterization of adrenomedullin 1 and calcitonin gene-related peptide 1 receptor reporter cell lines

Adrenomedullin (ADM) and calcitonin gene-related peptide (CGRP) receptors and their respective ligands play important roles in cardiovascular (patho-)physiology. Functional expression of ADM and CGRP receptors requires the presence of the calcitonin receptor-like receptor (CRLR) together with receptor-activity-modifying proteins (RAMPs). We have characterized the expression patterns of CRLR and RAMP1 to RAMP3 in human cardiovascular-related tissues by quantitative polymerase chain reaction. We could identify high expression levels of CRLR, RAMP1, and RAMP2 in human heart and various blood vessels. RAMP3 expression in these tissues, however, was detectable at significantly lower levels. In addition, we describe here a novel, aequorin luminescence-based G protein-coupled receptor reporter assay that enables the real-time detection of receptor activation in living cells. In the assay system, intracellular cAMP levels are monitored with high sensitivity by using a modified, heteromultimeric cyclic nucleotide-gated channel mediating calcium influx. G(q)-coupled receptor activation is detected via aequorin luminescence stimulated by calcium release from intracellular stores. Using this novel reporter assay, we established and characterized stable ADM1 and CGRP1 receptor cell lines. The peptide ligands ADM, CGRP1, and CGRP2 were characterized as potent agonists at their respective receptors. In contrast, intermedin acted as a weak agonist on both receptors and showed only partial agonism on the ADM1 receptor. Agonist activities were effectively antagonized by the receptor antagonists ADM(22-52) and CGRP(8-37). Various vasoactive ADM fragments were also characterized but showed no activity on the ADM1 receptor cell line. In addition, luminescence signal kinetics after activation of G(s)- and G(q)-coupled receptors were found to be markedly different.

One-sided limb lymphedema in a liver transplant recipient receiving sirolimus

Sirolimus (SRL) is associated with many side effects including hypercholesterolemia, anaemia, impaired wound healing and abnormal liver function tests. Limb lymphedema has only been reported several times in renal transplant recipients. We present a case of lower limb lymphedema that occurred in a 59-year-old liver transplant recipient after being on a SRL regimen for seven months. Extensive diagnostic investigations could not reveal signs of infection, venous obstruction or malignancy. After discontinuation of SRL, the lymphedema gradually resolved during the next three months. The pathologic mechanism behind this phenomenon is unknown, but antiangiogenetic and antiproliferative properties of SRL have been hold responsible. Further studies are necessary to explain this rare side effect.

Probing the substrate specificity of the ergothioneine transporter with methimazole, hercynine, and organic cations

Recently, we have identified the ergothioneine (ET) transporter ETT (gene symbol SLC22A4). Much interest in human ETT has been generated by case-control studies that suggest an association of polymorphisms in the SLC22A4 gene with susceptibility to chronic inflammatory diseases. ETT was originally designated a multispecific novel organic cation transporter (OCTN1). Here we reinvestigated, based on stably transfected 293 cells and with ET as reference substrate, uptake of quinidine, verapamil, and pyrilamine. ETT from human robustly catalyzed transport of ET (68micfrol/(minmgprotein)), but no transport of organic cations was discernible. With ET as substrate, ETT was relatively resistant to inhibition by selected drugs; the most potent inhibitor was verapamil (K(i)=11micromol/l). The natural compound hercynine and antithyroid drug methimazole are related in structure to ET. However, efficiency of ETT-mediated transport of methimazole (K(i)=7.5mmol/l) was 130-fold lower, and transport of hercynine (K(i)=1.4mmol/l) was 25-fold lower than transport of ET. ETT from mouse, upon expression in 293 cells, catalyzed high affinity, sodium-driven uptake of ET very similar to ETT from human. Additional real-time PCR experiments based on 16 human tissues revealed ETT mRNA levels considerably lower than in bone marrow. Our experiments establish that ETT is highly specific for its physiological substrate ergothioneine. ETT is not a cationic drug transporter, and it does not have high affinity for organic cation inhibitors. Detection of ETT mRNA or protein can therefore be utilized as a specific molecular marker of intracellular ET activity.

Hepatic stellate cells express synemin, a protein bridging intermediate filaments to focal adhesions

BACKGROUND AND AIMS

In the liver, stellate cells play several important (patho)physiological roles. They express a broad but variable spectrum of intermediate filament (IF) proteins. The aim of this study was to investigate the expression and functions of the intermediate filament protein synemin in hepatic stellate cells (HSCs).

METHODS

In isolated and cultured rat HSCs, synemin expression was examined by quantitative reverse transcriptase polymerase chain reaction, western blotting, and immunocytochemistry. Protein-protein interaction between synemin and possible binding partners was investigated by co-immunoprecipitation and confocal microscopy.

RESULTS

Expression of synemin was significantly downregulated with increased culture time. In 1-day cultured HSCs, synemin associated with other IF proteins (GFAP, desmin, and vimentin), and with the focal adhesion proteins vinculin and talin, but not with alpha-actinin or paxillin. Synemin IF and focal adhesion proteins co-localised in long slender processes, but not in the lamellipodia. In human and rat liver tissue, the presence of synemin was investigated by immunohistochemistry. In normal rat and human livers, synemin immunoreactivity was found in HSCs, smooth muscle cells of hepatic arterioles, and nerve bundles in portal tracts, but not in portal fibroblasts. In CCl4-intoxicated rat livers and in human cirrhotic livers, immunoreactivity for synemin in the parenchymal tissue was decreased. Thus synemin was expressed in quiescent HSCs but not in portal fibroblasts; and synemin expression decreased with HSC activation in vivo during chronic liver damage and with HSC activation in culture.

CONCLUSIONS

Synemin forms heteropolymeric filaments with type-III IF proteins and acts as a bridging protein between IFs and a specific type of focal adhesions.

Review article: the treatment of non-alcoholic steatohepatitis with thiazolidinediones

It is generally accepted that non-alcoholic fatty liver disease will be the most frequent liver disease in the near future and that the management of patients with non-alcoholic fatty liver disease will be a challenge for hepatologists in the next decades. Non-alcoholic fatty liver disease is considered the hepatic manifestation of the metabolic syndrome, in which insulin resistance plays a crucial role. Although steatosis will often not progress to severe liver disease, in some patients, it results in cirrhosis and even hepatocellular carcinoma. Therefore, it is important to identify those patients at risk for developing fibrosis. Age, diabetes, obesity and hypertriglyceridaemia are independent risk factors for fibrosis in patients with elevated serum alanine aminotransferase levels and steatosis on ultrasound. The presence of multiple metabolic disorders increases the risk. Apart from diet, exercise and correction of underlying metabolic abnormalities, no specific treatment is available at the moment. Theoretically, thiazolidinediones are an attractive way to treat non-alcoholic fatty liver disease, because they improve insulin resistance. Some preliminary studies with thiazolidinediones were encouraging, as steatosis, inflammation and fibrosis improved in a substantial number of patients. Although no serious side effects occurred in the pilot studies, we should look vigilantly for hepatotoxicity, as the first generation thiazolidinediones proved to be toxic for the liver.

Discovery of the ergothioneine transporter

Variants of the SLC22A4 gene are associated with susceptibility to rheumatoid arthritis and Crohn's disease. SLC22A4 codes for an integral membrane protein, OCTN1, that has been presumed to carry organic cations like tetraethylammonium across the plasma membrane. Here, we show that the key substrate of this transporter is in fact ergothioneine (ET). Human OCTN1 was expressed in 293 cells. A substrate lead, stachydrine (alias proline betaine), was identified by liquid chromatography MS difference shading, a new substrate search strategy. Analysis of transport efficiency of stachydrine-related solutes, affinity, and Na+ dependence indicates that the physiological substrate is ET. Efficiency of transport of ET was as high as 195 microl per min per mg of protein. By contrast, the carnitine transporter OCTN2 from rat did not transport ET at all. Because ET is transported >100 times more efficiently than tetraethylammonium and carnitine, we propose the functional name ETT (ET transporter) instead of OCTN1. ET, all of which is absorbed from food, is an intracellular antioxidant with metal ion affinity. Its particular purpose is unresolved. Cells with expression of ETT accumulate ET to high levels and avidly retain it. By contrast, cells lacking ETT do not accumulate ET, because their plasma membrane is virtually impermeable for this compound. The real-time PCR expression profile of human ETT, with strong expression in CD71+ cells, is consistent with a pivotal function of ET in erythrocytes. Moreover, prominent expression of ETT in monocytes and SLC22A4 polymorphism associations suggest a protective role of ET in chronic inflammatory disorders.

Expression of somatostatin receptors in normal and cirrhotic human liver and in hepatocellular carcinoma

BACKGROUND

Somatostatin analogues have been used with conflicting results to treat advanced hepatocellular carcinoma (HCC). The aim of this study was to investigate expression of somatostatin receptor (SSTR) subtypes in human liver, and to examine the effect of selective SSTR agonists on proliferation, apoptosis, and migration of hepatoma cells (HepG2, HuH7) and hepatic stellate cells (HSCs).

METHODS

Expression of SSTRs in cell lines, normal and cirrhotic liver, and HCC was examined by immunohistochemistry and reverse transcription-polymerase chain reaction. Effects of SSTR agonists on proliferation and apoptosis of tumour cells and HSCs were assessed by the 5-bromo-2' deoxyuridine and TUNEL methods, respectively. The influence of SSTR agonists on migration was investigated using Boyden chambers.

RESULTS

In normal liver, both hepatocytes and HSCs were negative for all five SSTRs. Cirrhotic liver and HCC as well as cultured hepatoma cells and HSCs expressed all five SSTRs, both at the protein and mRNA levels, except for HuH7 cells which did not immunoreact with SSTR3. None of the agonists influenced proliferation or apoptosis. However, compared with untreated cells, L-797,591, an SSTR1 agonist, reduced migration of HepG2, HuH7, and HSCs significantly to 88 (7)% (p<0.05), 83 (11)% (p<0.05), and 67 (13)% (p<0.01), respectively.

CONCLUSIONS

Cirrhotic liver and HCC express SSTRs. Although the somatostatin analogues used in this study did not affect proliferation and apoptosis, stimulation of SSTR1 may decrease invasiveness of HCC by reducing migration of hepatoma cells and/or HSCs. Clinical trials evaluating somatostatin analogues for the treatment of HCC should take these findings into account.

Metastatic follicular dendritic cell sarcoma of the stomach: a case report and review of the literature

Follicular dendritic cell (FDC) sarcomas are rare tumours, typically seen in lymph nodes. However, in about one third of the reported cases, a FDC sarcoma presents as an extranodal mass. Involvement of the gastrointestinal tract is extremely rare, and only 3 cases have been described to date. We report on a 40-year-old female patient with a follicular dendritic cell sarcoma located in the stomach and the presence of a metastasis in the liver at the time of diagnosis. Severe asthenia, nausea, back pain and loss of weight were the presenting symptoms. A CT scan of the abdomen and an upper gastrointestinal endoscopy revealed a tumour mass in the stomach. The diagnosis of a FDC sarcoma was made on histological and immunohistochemical findings. We report the second case of a FDC sarcoma presenting in the stomach. Due to its rarity, a FDC sarcoma seldom enters the differential diagnosis of spindle cells neoplasms of the gastrointestinal tract. Complete surgical resection is the treatment of choice for FDC sarcoma.

Pharmacological rationale for the use of somatostatin and analogues in portal hypertension

Somatostatin and its analogue octreotide have been used for two decades to treat oesophageal variceal haemorrhage. The drug was introduced because of its capacity to decrease portal venous pressure without major side effects. In clinical trials assessing the efficacy of somatostatin and long-acting analogues in arresting variceal haemorrhage, conflicting results have been obtained. Furthermore, in haemodynamic studies evaluating the effects of somatostatin and analogues in patients with cirrhosis, divergent effects were observed. The main reason for these differences is probably related to different affinities of the drugs for different somatostatin receptor subtypes. The effects of somatostatin and analogues are mediated via five different G-protein coupled receptors (somatostatin receptor subtypes 1-5), which regulate the activity of ion channels (Ca2+, K+, Na+ and Cl-) and enzymes (adenyl cyclase, phospholipase C, phospholipase A2, phosphoinositide 3-kinase and guanylate cyclase) responsible for the synthesis or degradation of intracellular second messengers including cyclic AMP, inositol 1,4,5-trisphosphate, diacylglycerol and cyclic GMP. Despite universal use of somatostatin, the cellular and biochemical mechanisms of its effects in portal hypertension are relatively poorly studied and remain incompletely understood. In this review, we summarize relevant signal transduction of somatostatin and analogues, the haemodynamic effects of the drugs and the possible mechanisms by which these effects are mediated.