Impact of Sarcopenia on the Survival of Patients with Hepatocellular Carcinoma Treated with Sorafenib.

BACKGROUND AND AIMS: Sarcopenia has been associated with poor outcomes in patients with cirrhosis and hepatocellular carcinoma. We investigated the impact of sarcopenia on survival in patients with advanced hepatocellular carcinoma treated with Sorafenib. METHODS: A total of 328 patients were retrospectively analyzed. All patients had an abdominal CT scan within 8 weeks prior to the start of treatment. Two cohorts of patients were analyzed: the "Training Group" (215 patients) and the "Validation Group" (113 patients). Sarcopenia was defined by reduced skeletal muscle index, calculated from an L3 section CT image. RESULTS: Sarcopenia was present in 48% of the training group and 50% of the validation group. At multivariate analysis, sarcopenia (HR: 1.47, p = 0.026 in training; HR 1.99, p = 0.033 in validation) and MELD > 9 (HR: 1.37, p = 0.037 in training; HR 1.78, p = 0.035 in validation) emerged as independent prognostic factors in both groups. We assembled a prognostic indicator named "SARCO-MELD" based on the two independent prognostic factors, creating three groups: group 1 (0 prognostic factors), group 2 (1 factor) and group 3 (2 factors), the latter with significantly worse survival and shorter time receiving treatment.

Multiple regions within junctin drive its interaction with calsequestrin-1 and its localization to triads in skeletal muscle.

Junctin is a transmembrane protein of striated muscles, located at the junctional sarcoplasmic reticulum (SR). It is characterized by a luminal C-terminal tail, through which it functionally interacts with calsequestrin and the ryanodine receptor (RyR). Interaction with calsequestrin was ascribed to the presence of stretches of charged amino acids (aa). However, the regions able to bind calsequestrin have not been defined in detail. We report here that, in non-muscle cells, junctin and calsequestrin assemble in long linear regions within the endoplasmic reticulum, mirroring the formation of calsequestrin polymers. In differentiating myotubes, the two proteins colocalize at triads, where they assemble with other proteins of the junctional SR. By performing GST pull-down assays with distinct regions of the junctin tail, we identified two KEKE motifs that can bind calsequestrin. In addition, stretches of charged aa downstream these motifs were found to also bind calsequestrin and the RyR. Deletion of even one of these regions impaired the ability of junctin to localize at the junctional SR, suggesting that interaction with other proteins at this site represents a key element in junctin targeting.

A novel homozygous mutation in the TRDN gene causes a severe form of pediatric malignant ventricular arrhythmia.

BACKGROUND: Triadin is a protein expressed in cardiac and skeletal muscle that has an essential role in the structure and functional regulation of calcium release units and excitation-contraction coupling. Mutations in the triadin gene (TRDN) have been described in different forms of human arrhythmia syndromes with early onset and severe arrhythmogenic phenotype, including triadin knockout syndrome. OBJECTIVE: The purpose of this study was to characterize the pathogenetic mechanism underlying a case of severe pediatric malignant arrhythmia associated with a defect in the TRDN gene. METHODS: We used a trio whole exome sequencing approach to identify the genetic defect in a 2-year-old boy who had been resuscitated from sudden cardiac arrest and had frequent episodes of ventricular fibrillation and a family history positive for sudden death. We then performed in vitro functional analysis to investigate possible pathogenic mechanisms underlying this severe phenotype. RESULTS: We identified a novel homozygous missense variant (p.L56P) in the TRDN gene in the proband that was inherited from the heterozygous unaffected parents. Expression of a green fluorescent protein (GFP)-tagged mutant human cardiac triadin isoform (TRISK32-L56P-GFP) in heterologous systems revealed that the mutation alters protein dynamics. Furthermore, when co-expressed with the type 2 ryanodine receptor, caffeine-induced calcium release from TRISK32-L56P-GFP was relatively lower compared to that observed with the wild-type construct. CONCLUSION: The results of this study allowed us to hypothesize a pathogenic mechanism underlying this rare arrhythmogenic recessive form, suggesting that the mutant protein potentially can trigger arrhythmias by altering calcium homeostasis.

Molecular determinants of homo- and heteromeric interactions of Junctophilin-1 at triads in adult skeletal muscle fibers.

In adult skeletal muscles, 2 junctophilin isoforms (JPH1 and JPH2) tether the sarcoplasmic reticulum (SR) to transverse tubule (T-tubule) membranes, generating stable membrane contact sites known as triads. JPHs are anchored to the membrane of the SR by a C-terminal transmembrane domain (TMD) and bind the T-tubule membrane through their cytosolic N-terminal region, which contains 8 lipid-binding (MORN) motifs. By combining expression of GFP-JPH1 deletion mutants in skeletal muscle fibers with in vitro biochemical experiments, we investigated the molecular determinants of JPH1 recruitment at triads in adult skeletal muscle fibers. We found that MORN motifs bind PI(4,5)P2 in the sarcolemma, but do not mediate the selective localization of JPH1 at the T-tubule compartment of triads. On the contrary, fusion proteins containing only the TMD of JPH1 were able to localize at the junctional SR compartment of the triad. Bimolecular fluorescence complementation experiments indicated that the TMD of JPH1 can form dimers, suggesting that the observed localization at triads may result from dimerization with the TMDs of resident JPH1. A second domain, capable of mediating homo- and heterodimeric interactions between JPH1 and JPH2 was identified in the cytosolic region. FRAP experiments revealed that removal of either one of these 2 domains in JPH1 decreases the association of the resulting mutant proteins with triads. Altogether, these results suggest that the ability to establish homo- and heterodimeric interactions with resident JPHs may support the recruitment and stability of newly synthesized JPHs at triads in adult skeletal muscle fibers.

Negative chronotropism, positive inotropism and lusitropism of 3,5-di-t-butyl-4-hydroxyanisole (DTBHA) on rat heart preparations occur through reduction of RyR2 Ca2+ leak.

3,5-Di-t-butyl-4-hydroxyanisole (DTBHA) is considered as an activator of the skeletal muscle sarcoplasmic reticulum (SR) Ca2+-uptake, endowed with antioxidant and L-type Ca2+ channel blocking activities. In this study we assessed the cardiac effects of DTBHA on Langendorff perfused rat hearts, isolated rat atria and rat cardiac SR membrane vesicles, as well as on several SERCA isoforms of membrane preparations. Moreover, in order to clarify its molecular mechanism of action Ca2+ imaging experiments were carried out on HEK293 cells transiently transfected with RyR2 channel. Docking of DTBHA at the rat RyR2 protein was investigated in silico. In Langendorff perfused rat hearts, DTBHA significantly increased, in a concentration-dependent manner, left ventricular pressure and diastole duration, while reducing heart rate and the time-constant of isovolumic relaxation, leaving unaltered coronary perfusion pressure. At the maximum concentration tested (30 µM), it significantly prolonged PQ interval, but left the corrected QT intervals unaffected. In spontaneously beating atria, DTBHA decreased sinus rate in a concentration-dependent manner. DTBHA, at concentrations higher than 10 µM, increased Ca2+ uptake in cardiac SR without affecting Ca2+-dependent ATPase activity assayed on several SERCA isoforms. Moreover, DTBHA antagonized thapsigargin-stimulated Ca2+ leak in cardiac SR and reduced caffeine-induced, RyR2-activated Ca2+ release in RyR2 expressing HEK293 cells. Using computational approaches, DTBHA showed a good affinity outline into binding sites of RyR2 protein. In conclusion, DTBHA behaved like a negative chronotropic, a positive inotropic and a lusitropic agent on rat heart preparations and improved cardiac SR Ca2+ uptake by lowering SR Ca2+ leak.

Reinfusion of highly purified CD133+ bone marrow-derived stem/progenitor cells in patients with end-stage liver disease: A phase I clinical trial.

BACKGROUND: Bone marrow stem/progenitor cells seem to be effective in liver regeneration after tissue injury. AIM: To evaluate the feasibility and safety of the mobilization and reinfusion of CD133+ stem/progenitor cells in patients with end-stage liver disease. METHODS: Autologous CD133+ stem/progenitor cells, mobilized with granulocyte-colony stimulating factor, were collected by leukapheresis and reinfused at increasing doses through the hepatic artery starting from 5×10(4)/kg up to 1×10(6)/kg. RESULTS: 16 subjects with Model for End-stage Liver Disease (MELD) score between 17 and 25 were enrolled, 14 mobilized an adequate number of CD133+ stem/progenitor cells and 12 were reinfused. No severe adverse events related to the procedure were reported. MELD score significantly worsened during mobilization in Child Turcotte Pugh-C patients. A significant improvement of liver function was observed 2 months after reinfusion (MELD 19.5 vs. 16; P=0.045). Overall, 5 patients underwent liver transplantation within 12 months from reinfusion and 2 died because of progressive liver failure. CONCLUSIONS: CD133+ stem/progenitor cells reinfusion in patients with end-stage liver disease is feasible and safe. A worsening of liver function was observed during mobilization in Child Turcotte Pugh-C patients. The temporary improvement of MELD score after reinfusion suggests that stem cells therapy may be a "bridge to transplant" approach for these patients.

Hepatitis C virus recurrence after liver transplantation: a 10-year evaluation.

AIM: To evaluate the predictors of 10-year survival of patients with hepatitis C recurrence. METHODS: Data from 358 patients transplanted between 1989 and 2010 in two Italian transplant centers and with evidence of hepatitis C recurrence were analyzed. A χ(2), Fisher's exact test and Kruskal Wallis' test were used for categorical and continuous variables, respectively. Survival analysis was performed at 10 years after transplant using the Kaplan-Meier method, and a log-rank test was used to compare groups. A P level less than 0.05 was considered significant for all tests. Multivariate analysis of the predictive role of different variables on 10-year survival was performed by a stepwise Cox logistic regression. RESULTS: The ten-year survival of the entire population was 61.2%. Five groups of patients were identified according to the virological response or lack of a response to antiviral treatment and, among those who were not treated, according to the clinical status (mild hepatitis C recurrence, "too sick to be treated" and patients with comorbidities contraindicating the treatment). While the 10-year survival of treated and untreated patients was not different (59.1% vs 64.7%, P = 0.192), patients with a sustained virological response had a higher 10-year survival rate than both the "non-responders" (84.7% vs 39.8%, P < 0.0001) and too sick to be treated (84.7% vs 0%, P < 0.0001). Sustained virological responders had a survival rate comparable to patients untreated with mild recurrence (84.7% vs 89.3%). A sustained virological response and young donor age were independent predictors of 10-year survival. CONCLUSION: Sustained virological response significantly increased long-term survival. Awaiting the interferon-free regimen global availability, antiviral treatment might be questionable in selected subjects with mild hepatitis C recurrence.

Increase of ribavirin dose improves sustained virological response in HCV-genotype 1 patients with a partial response to peg-interferon and ribavirin.

BACKGROUND AND AIM: In patients with chronic hepatitis C receiving Peg interferon/ribavirin (PEG-IFN/RBV) who do not achieve ≥ 2 log-reduction in HCV-RNA at week 12 (null responders, NR) and in those with ≥ 2 log-decrease but detectable at week 24 (partial responders, PR) the probability to achieve the sustained virological response (SVR) is almost null. The aim of this study was to investigate the efficacy of individualized schedule of progressively increased RBV doses in the setting of PEG-IFN/RBV treatment. MATERIAL AND METHODS: PR or NR to PEG-IFN/RBV instead of discontinuing treatment were enrolled to receive increasing doses of RBV until a target theoretical concentration ([tRBV]) of ≥ 15 µmol/L (by pharmacokinetic formula based on glomerular filtration rate). HCV-RNA was assessed every 4 weeks and, if detectable, RBV dose was gradually increased until negativization. Twelve weeks later, patients with detectable HCV-RNA discontinued therapy while those with undetectable HCV-RNA continued for further 48 weeks. RESULTS: Twenty genotype-1 patients (8 NR and 12 PR) were enrolled. After 12 weeks 9 (45%) were still HCV-RNA positive and were discontinued, while remaining 11 had undetectable HCV-RNA. One stopped treatment for side effects. Ten completed treatment. Five (all PR) achieved SVR. Side effects incidence was similar to that observed during PEG-IFN/RBV. CONCLUSIONS: In conclusion, RBV high doses, according to individualized schedule, increase SVR in PR on a similar extent to that of triple therapy but without increase of side effects. Such treatment should be considered in PR with no access or intolerant to protease inhibitors (PI).

Distinct regions of triadin are required for targeting and retention at the junctional domain of the sarcoplasmic reticulum.

Ca2+ release, which is necessary for muscle contraction, occurs at the j-SR (junctional domain of the sarcoplasmic reticulum). It requires the assembly of a large multiprotein complex containing the RyR (ryanodine receptor) and additional proteins, including triadin and calsequestrin. The signals which drive these proteins to the j-SR and how they assemble to form this multiprotein complex are poorly understood. To address aspects of these questions we studied the localization, dynamic properties and molecular interactions of triadin. We identified three regions, named TR1 (targeting region 1), TR2 and TR3, that contribute to the localization of triadin at the j-SR. FRAP experiments showed that triadin is stably associated with the j-SR and that this association is mediated by TR3. Protein pull-down experiments indicated that TR3 contains binding sites for calsequestrin-1 and that triadin clustering can be enhanced by binding to calsequestrin-1. These findings were confirmed by FRET experiments. Interestingly, the stable association of triadin to the j-SR was significantly decreased in myotubes from calsequestrin-1 knockout mice. Taken together, these results identify three regions in triadin that mediate targeting to the j-SR and reveal a role for calsequestrin-1 in promoting the stable association of triadin to the multiprotein complex associated with RyR.

Obscurin is required for ankyrinB-dependent dystrophin localization and sarcolemma integrity.

Obscurin is a large myofibrillar protein that contains several interacting modules, one of which mediates binding to muscle-specific ankyrins. Interaction between obscurin and the muscle-specific ankyrin sAnk1.5 regulates the organization of the sarcoplasmic reticulum in striated muscles. Additional muscle-specific ankyrin isoforms, ankB and ankG, are localized at the subsarcolemma level, at which they contribute to the organization of dystrophin and ß-dystroglycan at costameres. In this paper, we report that in mice deficient for obscurin, ankB was displaced from its localization at the M band, whereas localization of ankG at the Z disk was not affected. In obscurin KO mice, localization at costameres of dystrophin, but not of ß-dystroglycan, was altered, and the subsarcolemma microtubule cytoskeleton was disrupted. In addition, these mutant mice displayed marked sarcolemmal fragility and reduced muscle exercise tolerance. Altogether, the results support a model in which obscurin, by targeting ankB at the M band, contributes to the organization of subsarcolemma microtubules, localization of dystrophin at costameres, and maintenance of sarcolemmal integrity.

Long-term antiviral treatment for recurrent hepatitis C after liver transplantation.

BACKGROUND AND AIMS: The management of patients treated for hepatitis C recurrence after liver transplantation and not achieving virological response following treatment with interferon plus ribavirin is controversial. METHODS: A retrospective analysis of the outcomes of 70 patients non-responders to antiviral treatment after liver transplantation was performed. Twenty-one patients (30.0%; Group A) were treated for ≤ 12 months and 49 (70.0%; Group B) for more than 12 months. RESULTS: The 2 groups were comparable for main demographic, clinical and pathological variables. Median duration of antiviral treatment was 8.2 months in Group A and 33.4 months in Group B. No patient achieved a complete virological response. The 5-year patient hepatitis C-related survival rate was 49.2% in Group A and 88.3% in Group B (P=0.002), while the 5-year graft survival rate was 49.2% in Group A and 85.9% in Group B (P=0.007). The median yearly fibrosis progression rate was 1.21 per year in Group A and 0.40 per year in Group B (P=0.001). CONCLUSIONS: Prolonged antiviral treatment showed an overall beneficial effect in transplanted patients with a recurrent hepatitis C infection and not responding to conventional therapy. The treatment should be continued as long as it is permitted, in order to improve clinical and histological outcomes.

Liver transplantation for patients with alcoholic liver disease: an open question.

End-stage alcoholic liver disease is a recognised indication for liver transplantation but some questions on the matter remain open. It is difficult to quantify alcohol consumption, and a single definition of post-transplant relapse is lacking. Moreover, there are no internationally accepted criteria for the selection of candidates for liver transplantation and the eligibility parameters for these patients are controversial. Additional clinical and psychological evaluations are necessary in this setting, especially to establish the risk of alcohol relapse. Nevertheless, patient and graft survival rates after liver transplantation in alcoholic liver disease are comparable to those after transplant for other aetiologies, alcohol consumption relapse being one of the most important problems in the post-transplant phase. In conclusion, alcohol-related liver disease is a good indication for liver transplantation. The main future goals are to formulate a well-defined pre-transplant approach and a single definition of alcohol relapse and to improve prevention strategies.

Characterisation of a stereotypical cellular and extracellular adult liver progenitor cell niche in rodents and diseased human liver.

BACKGROUND: Stem/progenitor cell niches in tissues regulate stem/progenitor cell differentiation and proliferation through local signalling. OBJECTIVE: To examine the composition and formation of stem progenitor cell niches. METHODS: The composition of the hepatic progenitor cell niche in independent models of liver injury and hepatic progenitor cell activation in rodents and humans was studied. To identify the origin of the progenitor and niche cells, sex-mismatched bone marrow transplants in mice, who had received the choline-ethionine-deficient-diet to induce liver injury and progenitor cell activation, were used. The matrix surrounding the progenitor cells was described by immunohistochemical staining and its functional role controlling progenitor cell behaviour was studied in cell culture experiments using different matrix layers. RESULTS: The progenitor cell response in liver injury is intimately surrounded by myofibroblasts and macrophages, and to a lesser extent by endothelial cells. Hepatic progenitor cells are not of bone marrow origin; however, bone marrow-derived cells associate intimately with these cells and are macrophages. Laminin always surrounds the progenitor cells. In vitro studies showed that laminin aids maintenance of progenitor and biliary cell phenotype and promotes their gene expression (Dlk1, Aquaporin 1, gammaGT) while inhibiting hepatocyte differentiation and gene expression (CEPB/alpha). CONCLUSIONS: During liver damage in rodents and humans a stereotypical cellular and laminin niche forms around hepatic progenitor cells. Laminin helps maintenance of undifferentiated progenitor cells. The niche links the intrahepatic progenitor cells with bone marrow-derived cells and links tissue damage with progenitor cell-mediated tissue repair.

Polymorphism rtQ215H in primary resistance to adefovir dipivoxil in hepatitis B virus infection: a case report.

The benefit of lamivudine (LAM) in hepatitis B virus (HBV) infection is compromised by the progressively increasing emergence of drug-resistant mutant strains. Although the addition of adefovir dipivoxil (ADV) usually induces complete suppression of viral replication, primary non-response to ADV in LAM resistant patients has been reported in a variable percentage of cases. Here we report a case of a patient with HBV infection and hepatocellular carcinoma who started LAM therapy and subsequently developed virological breakthrough. The patient was given ADV, but HBV-DNA negativisation was not reached. However, HBV clearance was obtained when the patient was switched from ADV to tenofovir. Virological evaluations showed two well-known LAM-related mutations (rtL180M and rtM204I) in addition to reverse-transcriptase rtQ215H. This is the first case suggesting that this mutation may have an impact on viral replication. Finally, we also report that rtQ215H is responsive to tenofovir.

Stem cells for end stage liver disease: how far have we got?

End stage liver disease (ESLD) is a health problem worldwide. Liver transplantation is currently the only effective therapy, but its many drawbacks include a shortage of donors, operative damage, risk of rejection and in some cases recidivism of the pre-transplant disease. These factors account for the recent growing interest in regenerative medicine. Experiments have sought to identify an optimal source of stem cells, sufficient to generate large amounts of hepatocytes to be used in bioartificial livers or injected in vivo to repair the diseased organ. This update aims to give non-stem cell specialists an overview of the results obtained to date in this fascinating field of biomedical research.

Stem cell therapy for human liver cirrhosis: a cautious analysis of the results.

End-stage liver disease, and in particular human liver cirrhosis, represents a worldwide health problem. Currently, liver transplant is the only effective treatment, but it is affected by many problems, including relative lack of donors, operative damage, risk of rejection, and high costs. Stem cell therapy is very attractive in this setting because it has the potential to help tissue regeneration while providing minimally invasive procedures and few complications. Only a few clinical studies on the administration of bone marrow-derived stem cells to cirrhotic patients have been published up to now. Although preliminary results seem to be encouraging, the number of treated patients is too small and the study design not completely appropriate to demonstrate safety and efficacy of stem cell therapy in liver cirrhosis. Well designed, randomized, controlled studies are needed to confirm preliminary results and eventually clear doubts.

A randomized trial of induction doses of interferon alone or in combination with ribavirin or ribavirin plus amantadine for treatment of nonresponder patients with chronic hepatitis C.

BACKGROUND: Efficacy and safety of interferon induction therapy alone or in combination with ribavirin or ribavirin plus amantadine were evaluated in chronic hepatitis C patients who were nonresponders to primary antiviral treatment. METHODS: The study was designed to have 225 HCV nonresponder patients, but at an interim analysis the response rate difference between groups was lower than expected and the enrollment was stopped when 75 patients had been randomized to receive interferon-alpha2a (group A, n = 26), interferon-alpha2a plus 15 mg/kg per day of ribavirin (group B, n = 24), or interferon-alpha2a plus ribavirin plus 200 mg/day of amantadine hydrochloride (group C, n = 25). Treatment duration was 48 weeks. The dose of interferon was 6 MU/day for 4 weeks followed by 3 MU/day for the remaining 44 weeks. RESULTS: On intention-to-treat, the sustained virological response at 24 weeks of follow-up was 11.5% in group A, 12.5% in group B, and 12% in group C. Therapy was discontinued because of adverse effects in three patients in group A (11.5%), three in group B (12.5%), and two in group C (8%). CONCLUSIONS: Nonresponders with chronic hepatitis C may achieve a sustained virological response rate of approximately 12% if retreated with interferon induction treatment followed by administration of a daily dose. The addition of ribavirin or amantadine did not seem to improve the response rates.

A truncation in the RYR1 gene associated with central core lesions in skeletal muscle fibres.

A novel single-nucleotide deletion in exon 100 of the RYR1 gene, corresponding to deletion of nucleotide 14,510 in the human RyR1 mRNA (c14510delA), was identified in a man with malignant hyperthermia and in his two daughters who were normal for malignant hyperthermia. This deletion results in a RyR1 protein lacking the last 202 amino acid residues. All three subjects heterozygotic for the mutated allele presented with a prevalence of type 1 fibres with central cores, although none experienced clinical signs of myopathy. Expression of the truncated protein resulted in non-functional RYR1 calcium release channels. Expression of wild-type and RyR1(R4836fsX4838) proteins resulted in heterozygotic release channels with overall functional properties similar to those of wild-type RyR1 channels. Nevertheless, small differences in sensitivity to calcium and caffeine were observed in heterotetrameric channels, which also presented an altered assembly/stability in sucrose-gradient centrifugation analysis. Altogether, these data suggest that altered RYR1 tetramer assembly/stability coupled with subtle chronic changes in Ca2+ homoeostasis over the long term may contribute to the development of core lesions and incomplete malignant hyperthermia susceptibility penetrance in individuals carrying this novel RYR1 mutation.

Regenerative medicine and liver injury: what role for bone marrow derived stem cells?

In recent years, great interest has been aroused by the discovery of the ability of adult stem cells to contribute to regeneration processes and repair of damaged tissues. In particular, bone marrow derived stem cells (BMSCs), the most well known population of multipotent stem cells in adults, have been shown to be able to generate many different committed cellular types. In this review, we systematically organize the numerous hypotheses emerging from the most recent studies, in animal and humans, which evaluated the potentiality of BMSCs to contribute to tissue repair in different types of liver damage. Our aim is to give scientists and clinicians who are interested in regenerative medicine the rational basis for planning future studies on stem cell therapy for liver diseases.

Frequency and localization of mutations in the 106 exons of the RYR1 gene in 50 individuals with malignant hyperthermia.

Malignant hyperthermia (MH) is a dominantly inherited pharmacogenetic condition that manifests as a life-threatening hypermetabolic reaction when a susceptible individual is exposed to common volatile anesthetics and depolarizing muscle relaxants. Although MH appears to be genetically heterogeneous, RYR1 is the main candidate for MH susceptibility. However, since molecular analysis is generally limited to exons where mutations are more frequently detected, these are routinely found only in 30-50% of susceptible subjects. In this study the entire RYR1 coding region was analyzed in a cohort of 50 Italian MH susceptible (MHS) subjects. Thirty-one mutations, 16 of which were novel, were found in 43 individuals with a mutation detection rate of 86%, the highest reported for RYR1 in MH so far. These data provide clear evidence that mutations in the RYR1 gene are the predominant cause of MH.