Downregulation of CYP17A1 by 20-hydroxyecdysone: plasma progesterone and its vasodilatory properties.

Aim: To investigate the effect of 20-hydroxyecdysone on steroidogenic pathway genes and plasma progesterone, and its potential impact on vascular functions. Methods: Chimeric mice with humanized liver were treated with 20-hydroxyecdysone for 3 days, and hepatic steroidogenic pathway genes and plasma progesterone were measured by transcriptomics and GC-MS/MS, respectively. Direct effects on muscle and mesenteric arterioles were assessed by myography. Results: CYP17A1 was downregulated in 20-hydroxyecdysone-treated mice compared with untreated group (p = 0.04), with an insignificant increase in plasma progesterone. Progesterone caused vasorelaxation which was blocked by 60 mM KCl, but unaffected by nitric oxide synthase inhibition. Conclusion: In the short term, 20-hydroxyecdysone mediates CYP17A1 downregulation without a significant increase in plasma progesterone, which has a vasodilatory effect involving inhibition of voltage-dependent calcium channels, and the potential to enhance 20-hydroxyecdysone vasorelaxation.

Premortem anticoagulation timing and dose in donation after circulatory death: multicentre study of associations with graft function.

BACKGROUND: In controlled donation after circulatory determination of death (DCD), it is common to administer premortem heparin to potential donors. This practice remains controversial because there is limited evidence for it and there is the possibility of inducing hemorrhage. To our knowledge, no previous studies have assessed the effects of heparin timing and dose on graft function. METHODS: We performed a multicentre cohort study of consecutive DCD donors and the recipients of their organs. Anticoagulation administration was considered early if given near the time of withdrawal of life-sustaining measures and late if delayed until the onset of donor hypoxemia (oxygen saturation < 70%) or hypotension (systolic blood pressure < 60 mm Hg or mean blood pressure < 50 mm Hg). The anticoagulation dose was considered high if it was 300 units/kg or greater. RESULTS: Donor anticoagulation data were available for 301 kidney, 75 liver and 46 lung recipients. Heparin was administered in 92% of cases and was most commonly withheld in donors with cerebrovascular causes of death (p = 0.01). Administration was late in 59% and the dose was low in 27%. Among kidney recipients, there were no significant differences in need for dialysis, glomerular filtration rate over the first year after transplantation or graft survival on the basis of whether or not the donor received heparin, the timing of heparin administration or the dose of heparin. Among liver recipients, alkaline phosphatase concentrations over the first year were significantly higher among recipients who received organs from donors to whom lower doses of heparin had been administered. CONCLUSION: Premortem heparin is widely used in DCD cases, but there is variability in timing and dose, which was not associated with kidney outcomes in this study. Donor anticoagulation may have a greater impact in preventing biliary complications following liver transplantation.

Higher subcutaneous adipose tissue radiodensity is associated with increased mortality in patients with cirrhosis.

Background & Aims: Association between sarcopenia and mortality in cirrhosis is well recognised; however, little is known about the clinical implications of adipose tissue radiodensity, indicative of biological features. This study aimed to determine an association between high subcutaneous adipose tissue (SAT) radiodensity and survival, compare the prevalence of high SAT radiodensity between healthy population and patients with cirrhosis, and identify an association between computed tomography (CT)-measured SAT radiodensity and histological characteristics. Methods: Adult patients with cirrhosis (n = 786) and healthy donors (n = 129) with CT images taken as part of the liver transplant (LT) assessment were included. Abdominal SAT biopsies (1-2 g) were harvested from the incision site at the time of LT from 12 patients with cirrhosis. Results: The majority of patients were male (67%) with a mean model for end-stage liver disease (MELD) score of 15 ± 8. SAT radiodensity above -83 HU in females (sub-distribution hazard ratio [sHR] 1.84, 95% CI 1.20-2.85, p = 0.006) and higher than -74 HU in males (sHR 1.51, 95% CI 1.05-1.18, p = 0.02) was associated with the highest mortality risk after adjusting for confounders in competing risk analysis. The frequency of high SAT radiodensity was 26% for those with cirrhosis, compared with 2% in healthy donors (p <0.001). An inverse correlation was found between SAT radiodensity and the mean cross-sectional area of SAT adipocytes (r = -0.67, p = 0.02). Shrunken, smaller adipocytes with expanded interstitial space were predominant in patients with high SAT radiodensity, whereas larger adipocytes with a thin rim of cytoplasm were observed in patients with low SAT radiodensity (744 ± 400 vs. 1,521 ± 1,035 µm2, p <0.001). Conclusion: High SAT radiodensity frequently presents and is associated with a higher mortality in cirrhosis. SAT morphological rearrangement in patients with high SAT radiodensity might indicate diminished lipid stores and alterations in tissue characteristics. Lay summary: Poor quality of subcutaneous adipose tissue (fat under the skin) is associated with higher mortality in patients with end-stage liver disease. Fat cells are smaller in patients with poor adipose tissue quality.

The Transition to Microsurgical Technique for Hepatic Artery Reconstruction in Pediatric Liver Transplantation.

BACKGROUND: Hepatic artery thrombosis represents a potentially fatal complication following liver transplantation. Rates of hepatic artery thrombosis are significantly higher in children, with mortality reported up to 80 percent. Microsurgical anastomosis has been shown to decrease the rate of hepatic artery thrombosis and now represents the standard of care at the authors' institution. In this article, the authors present the largest study of its type directly comparing rates of hepatic artery thrombosis with and without microsurgical reconstruction of the hepatic artery. METHODS: All pediatric patients who underwent primary orthotopic liver transplantation between 1989 and 2018 were included. Patients were divided into two cohorts: standard anastomosis with loupes, and microsurgical anastomosis under the operating microscope. The authors' primary outcome was the rate of hepatic artery thrombosis. Secondary outcomes were graft survival, patient survival, retransplantation rate, requirement for intraoperative blood products, and length of stay. RESULTS: Two hundred thirty-one children met criteria for inclusion. One hundred eighty cases were performed with loupe magnification and 51 cases were performed under the microscope. The hepatic artery thrombosis rate was lower, but not significantly so (p = 0.114), in the microsurgical group [n = 1 (2.0 percent)] compared with the standard cohort [n = 15 (8.3 percent)]. Survival analysis revealed a significant increase in graft survival with microsurgical anastomosis (p = 0.020), but not patient survival (p = 0.196). The retransplantation rate was significantly lower with microsurgical anastomosis (p = 0.021). CONCLUSIONS: Microsurgical anastomosis was associated with a clinically important decrease in hepatic artery thrombosis compared with standard loupe anastomosis. The graft survival rate was significantly higher in the microsurgical cohort, with a reduced retransplantation rate at 1 year. On this basis, the authors recommend microsurgical hepatic artery anastomosis in cases of pediatric liver transplantation. . CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Membrane type 1 matrix metalloproteinase promotes LDL receptor shedding and accelerates the development of atherosclerosis.

Plasma low-density lipoprotein (LDL) is primarily cleared by LDL receptor (LDLR). LDLR can be proteolytically cleaved to release its soluble ectodomain (sLDLR) into extracellular milieu. However, the proteinase responsible for LDLR cleavage is unknown. Here we report that membrane type 1-matrix metalloproteinase (MT1-MMP) co-immunoprecipitates and co-localizes with LDLR and promotes LDLR cleavage. Plasma sLDLR and cholesterol levels are reduced while hepatic LDLR is increased in mice lacking hepatic MT1-MMP. Opposite effects are observed when MT1-MMP is overexpressed. MT1-MMP overexpression significantly increases atherosclerotic lesions, while MT1-MMP knockdown significantly reduces cholesteryl ester accumulation in the aortas of apolipoprotein E (apoE) knockout mice. Furthermore, sLDLR is associated with apoB and apoE-containing lipoproteins in mouse and human plasma. Plasma levels of sLDLR are significantly increased in subjects with high plasma LDL cholesterol levels. Thus, we demonstrate that MT1-MMP promotes ectodomain shedding of hepatic LDLR, thereby regulating plasma cholesterol levels and the development of atherosclerosis.

Liver Transplantation in Locally Unresectable, Undifferentiated Embryonal Cell Sarcoma.

BACKGROUND: Undifferentiated embryonal cell sarcoma (UESL) of the liver is the third most common malignant liver disease of childhood presenting as a rapidly enlarging intraabdominal mass. This systematic review explores the practicality of liver transplantation as a viable option in the treatment armamentarium for locally advanced undifferentiated embryonal cell sarcoma. METHODS: A systematic review of the literature was performed using Medline and Embase, from inception of databases to December 31, 2018. Keywords and MeSH headings used were embryonal sarcoma, mesenchymal sarcoma, and liver transplant. Reviews and manuscripts with incomplete data were excluded. RESULTS: Twenty-eight patients had orthotopic liver transplantation (OLT) as a curative treatment option. The median age at presentation was 8 and 27 years in the pediatric and adult population, respectively, with a similar male to female ratio. A majority of the patients presented with abdominal pain, palpable mass, and a normal alpha-feto-protein. The median tumor size was 15 cm mainly affecting the right lobe (62%) of the liver. Eighty-two percent of the patients underwent primary OLT and 5 patients had salvage OLT. One death (3.6%) was due to initial misdiagnosis and management for hepatoblastoma. Recurrence was noted in 7.1% of the population. The median follow-up was noted to be 28.5 months. The documented survival rate post-liver transplant for UESL was 96%. CONCLUSIONS: Based on available data and the very positive results therein, liver transplantation is a practical and justifiable use of a scarce resource as a treatment option for locally unresectable, undifferentiated embryonal cell sarcoma. The authors propose (accepting existence of different proposals) neoadjuvant therapy before curative resection, and if not achievable, then liver transplantation followed by adjuvant chemotherapy is an option for suitable candidates. For recurrent tumors after surgical resection, adjuvant therapy with salvage liver transplantation is an option.

Donation after circulatory determination of death in western Canada: a multicentre study of donor characteristics and critical care practices.

PURPOSE: Donation after circulatory determination of death (DCD) has been performed in Canada since 2006. Numerous aspects of donor management remain controversial. METHODS: We performed a multicentre cohort study involving potential DCD donors in western Canada (2008-2017), as well as recipients of their organs, to describe donor characteristics and critical care practices, and their relation to one-year recipient and graft survival. RESULTS: There were 257 patients in four provinces that underwent withdrawal of life-sustaining therapies (WLST) in anticipation of possible DCD. The proportion of patients that died within two hours of WLST ranged from 67% to 88% across provinces (P = 0.06), and was predicted by deeper coma (P = 0.01), loss of pupillary light or corneal reflexes (P = 0.02), and vasopressor use (P = 0.01). There were significant differences between provinces in time intervals from onset of hypotension to death (9-11 min; P = 0.02) and death to vascular cannulation (7-10 min; P < 0.001). There was inconsistency in pre-mortem heparin administration (82-96%; P = 0.03), including timing (before vs after WLST; P < 0.001) and dose (≥ 300 vs < 300 units·kg-1; P < 0.001). Donation after circulatory death provided organs for 321 kidney, 81 liver, and 50 lung transplants. One-year recipient and graft survival did not differ among provinces (range 85-90%, P = 0.45). Predictors of death or graft failure included older recipient age (odds ratio [OR] per year, 1.04; 95% confidence interval [CI],1.01 to 1.07) and male donor sex (OR, 3.35; 95% CI, 1.39 to 8.09), but not time intervals between WLST and cannulation or practices related to heparin use. CONCLUSION: There is significant variability in critical care DCD practices in western Canada, but this has not resulted in significant differences in recipient or graft survival. Further research is required to guide optimal management of potential DCD donors.

RéSUMé: OBJECTIF: Le don d'organes après décès cardiocirculatoire (DDC) est pratiqué au Canada depuis 2006. De nombreux aspects touchant à la prise en charge des donneurs demeurent controversés. MéTHODE: Nous avons réalisé une étude de cohorte multicentrique auprès de donneurs potentiels de DDC dans l'Ouest canadien (2008­2017), ainsi qu'auprès des récipiendaires de leurs organes, afin de décrire les caractéristiques des donneurs et les pratiques de soins intensifs, ainsi que la relation entre ces éléments et la survie à un an des récipiendaires et des organes greffés. RéSULTATS: Au total, 257 patients provenant de quatre provinces ont subi une interruption des traitements de survie en vue d'un possible DDC. La proportion de patients décédés dans les deux heures suivant l'interruption des traitements de survie allait de 67 % à 88 % dans toutes les provinces à l'étude (P = 0,06) et pouvait être prédite par une profondeur du coma plus importante (P = 0,01), la perte de la réaction pupillaire à la lumière ou des réflexes cornéens (P = 0,02), et l'utilisation de vasopresseurs (P = 0,01). Des différences significatives ont été observées entre les différentes provinces dans les intervalles de temps entre le début de l'hypotension et le décès (9­11 min; P = 0,02) et entre le décès et la canulation vasculaire (7­10 min; P < 0,001). Il y avait divergence dans l'administration d'héparine avant le décès (82-96 %; P = 0,03), notamment en ce qui concerne le moment d'administration (avant vs après l'interruption des traitements de survie; P < 0,001) et la posologie (≥ 300 vs < 300 unités·kg−1; P < 0,001). Le don après décès cardiocirculatoire a permis de procurer des organes pour 321 greffes rénales, 81 greffes hépatiques et 50 greffes pulmonaires. La survie à un an du récipiendaire et du greffon ne différait pas d'une province à l'autre (allant de 85 à 90 %, P = 0,45). Les prédicteurs de décès ou de la défaillance du greffon incluaient l'âge plus avancé du récipiendaire (rapport de cotes [RC] par année, 1,04; intervalle de confiance [IC] 95 %, 1,01 à 1,07) et un donneur de sexe masculin (RC, 3,35; IC 95 %, 1,39 à 8,09), mais pas les intervalles de temps entre l'interruption des traitements de survie et la canulation, ni les pratiques liées à l'utilisation d'héparine. CONCLUSION: Il existe une importante variabilité dans les pratiques de soins intensifs pour le DDC dans l'Ouest canadien, mais cette variabilité n'a pas résulté en différences significatives en matière de survie des récipiendaires ou des greffons. Des recherches supplémentaires sont nécessaires afin d'aiguiller la prise en charge optimale des donneurs potentiels de DDC.

Intraoperative continuous renal replacement therapy during liver transplantation: a pilot randomized-controlled trial (INCEPTION).

PURPOSE: To evaluate the feasibility of intraoperative continuous renal replacement therapy (IoCRRT) during liver transplantation (LT), in terms of recruitment, protocol adherence, and ascertainment of follow-up. METHODS: In this pilot randomized open-label controlled trial in adults receiving LT with a Model for End-Stage Liver Disease (MELD) score ≥ 25 and preoperative acute kidney injury (RIFLE - RISK or higher) and/or estimated glomerular filtration rate < 60 mL·min-1·1.73 m-2, patients were randomized to receive IoCRRT or standard of care (SOC). Primary endpoints were feasibility and adverse events. Primary analysis was intention-to-treat (n = 32) and secondary analysis was per-protocol (n = 28). RESULTS: The trial was stopped early because of slow patient accrual and inadequate funding. Sixty patients were enrolled and 32 (53%) were randomized (n = 15 IoCRRT; n = 17 SOC). Mean (standard deviation) MELD was 36 (8), 81% (n = 26) had cirrhosis; 69% (n = 22) received preoperative RRT; 66% (n = 21) received LT from the intensive care unit. Four patients (n = 2 IoCRRT, n = 2 SOC) did not receive LT post-randomization. Seven patients (41%) allocated to SOC crossed over intraoperatively to IoCRRT. Three patients were lost to follow-up at one year. No adverse events occurred related to IoCRRT. There were no differences in survival at one year (IoCRRT, 71% [n = 10/14] vs SOC, 93% [n = 14/15]; risk ratio, 0.77; 95% confidence interval, 0.54 to 1.1). In the per-protocol analysis (n = 28 received IoCRRT after randomization - n = 20 IoCRRT, n = 8 SOC), one-year survival was 92% and perioperative complications were similar between groups. Only one patient was receiving dialysis one year after LT. CONCLUSION: In this pilot randomized trial, IoCRRT was feasible and safe with no difference in complications. Crossover rates were high. Despite high preoperative severity of illness, one-year survival was excellent. These data can inform the design of a larger multicentre trial. TRIAL REGISTRATION: www.clinicalTrials.gov (NCT01575015); registered 12 April, 2012.

RéSUMé: OBJECTIF: Notre but était d'évaluer la faisabilité d'un traitement substitutif peropératoire continu de l'insuffisance rénale pendant une greffe hépatique, notamment en matière de recrutement, d'adhésion au protocole, et de suivi. MéTHODE: Dans cette étude randomisée contrôlée non aveugle pilote réalisée auprès d'adultes recevant une greffe hépatique avec un score MELD (Model for End-Stage Liver Disease) ≥ 25 et une insuffisance rénale aiguë préopératoire (RIFLE - RISQUÉ ou plus élevé) et/ou un taux de filtration glomérulaire estimé < 60 mL·min−1·1,73 m−2, les patients ont été randomisés à recevoir un traitement substitutif peropératoire continu de l'insuffisance rénale (le traitement) ou les soins habituels (la norme). Les critères d'évaluation principaux étaient la faisabilité et les événements indésirables. L'analyse principale était l'analyse du projet thérapeutique (intention-to-treat; n = 32) et l'analyse secondaire était l'analyse selon le protocole (n = 28). RéSULTATS: L'étude a été précocement interrompue en raison du recrutement lent de patients et du manque de fonds. Soixante patients ont été recrutés et 32 (53 %) ont été randomisés (n = 15 traitement; n = 17 norme). Le score MELD moyen (écart type) était de 36 (8), 81 % (n = 26) des patients souffraient de cirrhose; 69 % (n = 22) ont reçu un traitement substitutif de l'insuffisance rénale préopératoire; 66 % (n = 21) ont reçu une greffe hépatique à partir de l'unité de soins intensifs. Quatre patients (n = 2 traitement, n = 2 norme) n'ont pas reçu de greffe hépatique après la randomisation. Sept patients (41 %) alloués au groupe norme sont passés dans le groupe traitement en période peropératoire. Trois patients ont été perdus au suivi au cours de la première année. Aucun événement indésirable n'est survenu en association au traitement substitutif peropératoire continu de l'insuffisance rénale. Aucune différence en matière de survie à un an n'a été observée (traitement, 71 % [n = 10/14] vs norme, 93 % [n = 14/15]; risque relatif, 0,77; intervalle de confiance 95 %, 0,54 à 1,1). Dans l'analyse selon le protocole (n = 28 ont reçu un traitement après la randomisation - n = 20 traitement, n = 8 norme), la survie à un an était de 92 % et les complications périopératoires étaient semblables dans les deux groupes. Un seul patient recevait de la dialyse un an après la greffe hépatique. CONCLUSION: Dans cette étude randomisée pilote, le traitement substitutif peropératoire continu de l'insuffisance rénale s'est avéré faisable et sécuritaire, et aucune différence en matière de complications n'a été observée. Les taux de transfert d'un groupe à l'autre étaient élevés. Malgré une sévérité préopératoire élevée de la maladie, la survie à un an était excellente. Ces données peuvent être utiles pour concevoir une étude multicentrique plus importante. ENREGISTREMENT DE L'éTUDE: www.clinicalTrials.gov (NCT01575015); enregistrée le 12 avril 2012.

Mice with Chimeric Human Livers and Their Applications.

The complete life cycle of the hepatitis C virus (HCV) can be recapitulated in vivo using immunodeficient mice that have had their livers extensively repopulated with human hepatocytes. These human liver chimeric mouse models have enabled the study of many aspects of the HCV life cycle, including antiviral interventions that have helped to shape the curative landscape that is available today. The first human liver chimeric mouse model capable of supporting the HCV life cycle was generated in SCID-uPA mice. Although other human liver chimeric mouse models have since been developed, the SCID-uPA mouse model remains one of the most robust in vivo systems available for HCV studies. This chapter reviews development, validation and application of the SCID-uPA mouse model, and discusses their potential application for studying other liver-centric diseases and pathogens and for the design and testing of vaccine candidates for the eradication of HCV.

Metabolism of a Phenylarsenical in Human Hepatic Cells and Identification of a New Arsenic Metabolite.

Environmental contamination and human consumption of chickens could result in potential exposure to Roxarsone (3-nitro-4-hydroxyphenylarsonic acid), an organic arsenical that has been used as a chicken feed additive in many countries. However, little is known about the metabolism of Roxarsone in humans. The objective of this research was to investigate the metabolism of Roxarsone in human liver cells and to identify new arsenic metabolites of toxicological significance. Human primary hepatocytes and hepatocellular carcinoma HepG2 cells were treated with 20 or 100 µM Roxarsone. Arsenic species were characterized using a strategy of complementary chromatography and mass spectrometry. The results showed that Roxarsone was metabolized to more than 10 arsenic species in human hepatic cells. A new metabolite was identified as a thiolated Roxarsone. The 24 h IC50 values of thiolated Roxarsone for A549 lung cancer cells and T24 bladder cancer cells were 380 ± 80 and 42 ± 10 µM, respectively, more toxic than Roxarsone, whose 24 h IC50 values for A549 and T24 were 9300 ± 1600 and 6800 ± 740 µM, respectively. The identification and toxicological studies of the new arsenic metabolite are useful for understanding the fate of arsenic species and assessing the potential impact of human exposure to Roxarsone.

Protein O-fucosylation in Plasmodium falciparum ensures efficient infection of mosquito and vertebrate hosts.

O-glycosylation of the Plasmodium sporozoite surface proteins CSP and TRAP was recently identified, but the role of this modification in the parasite life cycle and its relevance to vaccine design remain unclear. Here, we identify the Plasmodium protein O-fucosyltransferase (POFUT2) responsible for O-glycosylating CSP and TRAP. Genetic disruption of POFUT2 in Plasmodium falciparum results in ookinetes that are attenuated for colonizing the mosquito midgut, an essential step in malaria transmission. Some POFUT2-deficient parasites mature into salivary gland sporozoites although they are impaired for gliding motility, cell traversal, hepatocyte invasion, and production of exoerythrocytic forms in humanized chimeric liver mice. These defects can be attributed to destabilization and incorrect trafficking of proteins bearing thrombospondin repeats (TSRs). Therefore, POFUT2 plays a similar role in malaria parasites to that in metazoans: it ensures the trafficking of Plasmodium TSR proteins as part of a non-canonical glycosylation-dependent endoplasmic reticulum protein quality control mechanism.The role of O-glycosylation in the malaria life cycle is largely unknown. Here, the authors identify a Plasmodium protein O-fucosyltransferase and show that it is important for normal trafficking of a subset of surface proteins, particularly CSP and TRAP, and efficient infection of mosquito and vertebrate hosts.

AMA1 and MAEBL are important for Plasmodium falciparum sporozoite infection of the liver.

The malaria sporozoite injected by a mosquito migrates to the liver by traversing host cells. The sporozoite also traverses hepatocytes before invading a terminal hepatocyte and developing into exoerythrocytic forms. Hepatocyte infection is critical for parasite development into merozoites that infect erythrocytes, and the sporozoite is thus an important target for antimalarial intervention. Here, we investigated two abundant sporozoite proteins of the most virulent malaria parasite Plasmodium falciparum and show that they play important roles during cell traversal and invasion of human hepatocytes. Incubation of P. falciparum sporozoites with R1 peptide, an inhibitor of apical merozoite antigen 1 (AMA1) that blocks merozoite invasion of erythrocytes, strongly reduced cell traversal activity. Consistent with its inhibitory effect on merozoites, R1 peptide also reduced sporozoite entry into human hepatocytes. The strong but incomplete inhibition prompted us to study the AMA-like protein, merozoite apical erythrocyte-binding ligand (MAEBL). MAEBL-deficient P. falciparum sporozoites were severely attenuated for cell traversal activity and hepatocyte entry in vitro and for liver infection in humanized chimeric liver mice. This study shows that AMA1 and MAEBL are important for P. falciparum sporozoites to perform typical functions necessary for infection of human hepatocytes. These two proteins therefore have important roles during infection at distinct points in the life cycle, including the blood, mosquito, and liver stages.

Clinical Impact of Portal Vein Thrombosis Prior to Liver Transplantation: A Retrospective Cohort Study

ABSTRACT Introduction. To identify the impact of portal vein thrombosis (PVT) and associated medical and surgical factors on outcomes post liver transplant (LT). Material and methods. Two analyses were performed. Analysis One: cohort study of 505 consecutive patients who underwent LT (Alberta) between 01/2002-12/2012. PVT was identified in 61 (14%) patients. Analysis Two: cohort study of 144 consecutive PVT patients from two sites (Alberta and London) during the same period. Cox multivariable survival analysis was used to identify independent associations with post-LT mortality. Results. In Analysis One (Alberta), PVT was not associated with post-LT mortality (log rank p = 0.99). On adjusted analysis, complete/occlusive PVT was associated with increased mortality (Hazard Ratio (HR) 8.4, p < 0.001). In Analysis Two (Alberta and London), complete/occlusive PVT was associated with increased mortality only on unadjusted analysis (HR 3.7, p = 0.02). On adjusted analysis, Hepatitis C (HR 2.1, p = 0.03) and post-LT portal vein re-occlusion (HR 3.2, p = 0.01) were independently associated with increased mortality. Conclusion: Well-selected LT patients who had PVT prior to LT had similar post-LT outcomes to non-PVT LT recipients. Subgroups of PVT patients who did worse post-LT (complete/occlusive thrombosis pre-LT, Hepatitis C or post-LT portal vein re-occlusion) warrant closer evaluation in listing and management post-LT.

Cell Traversal Activity Is Important for Plasmodium falciparum Liver Infection in Humanized Mice.

Malaria sporozoites are deposited into the skin by mosquitoes and infect hepatocytes. The molecular basis of how Plasmodium falciparum sporozoites migrate through host cells is poorly understood, and direct evidence of its importance in vivo is lacking. Here, we generated traversal-deficient sporozoites by genetic disruption of sporozoite microneme protein essential for cell traversal (PfSPECT) or perforin-like protein 1 (PfPLP1). Loss of either gene did not affect P. falciparum growth in erythrocytes, in contrast with a previous report that PfPLP1 is essential for merozoite egress. However, although traversal-deficient sporozoites could invade hepatocytes in vitro, they could not establish normal liver infection in humanized mice. This is in contrast with NF54 sporozoites, which infected the humanized mice and developed into exoerythrocytic forms. This study demonstrates that SPECT and perforin-like protein 1 (PLP1) are critical for transcellular migration by P. falciparum sporozoites and demonstrates the importance of cell traversal for liver infection by this human pathogen.

Clinical Impact of Portal Vein Thrombosis Prior to Liver Transplantation: A Retrospective Cohort Study.

INTRODUCTION: To identify the impact of portal vein thrombosis (PVT) and associated medical and surgical factors on outcomes post liver transplant (LT). MATERIAL AND METHODS: Two analyses were performed. Analysis One: cohort study of 505 consecutive patients who underwent LT (Alberta) between 01/2002-12/2012. PVT was identified in 61 (14%) patients. Analysis Two: cohort study of 144 consecutive PVT patients from two sites (Alberta and London) during the same period. Cox multivariable survival analysis was used to identify independent associations with post-LT mortality. RESULTS: In Analysis One (Alberta), PVT was not associated with post-LT mortality (log rank p = 0.99). On adjusted analysis, complete/occlusive PVT was associated with increased mortality (Hazard Ratio (HR) 8.4, p &lt; 0.001). In Analysis Two (Alberta and London), complete/occlusive PVT was associated with increased mortality only on unadjusted analysis (HR 3.7, p = 0.02). On adjusted analysis, Hepatitis C (HR 2.1, p = 0.03) and post-LT portal vein re-occlusion (HR 3.2, p = 0.01) were independently associated with increased mortality. CONCLUSION: Well-selected LT patients who had PVT prior to LT had similar post-LT outcomes to non-PVT LT recipients. Subgroups of PVT patients who did worse post-LT (complete/occlusive thrombosis pre-LT, Hepatitis C or post-LT portal vein re-occlusion) warrant closer evaluation in listing and management post-LT.

A positive feedback loop involving the Wnt/ß-catenin/MYC/Sox2 axis defines a highly tumorigenic cell subpopulation in ALK-positive anaplastic large cell lymphoma.

BACKGROUND: We have previously described the existence of two phenotypically distinct cell subsets in ALK-positive anaplastic large cell lymphoma (ALK + ALCL) based on their differential responsiveness to a Sox2 reporter (SRR2), with reporter-responsive (RR) cells being more tumorigenic and chemoresistant than reporter-unresponsive (RU) cells. However, the regulator(s) of RU/RR dichotomy are not identified. In this study, we aim to delineate the key regulator(s) of RU/RR dichotomy. METHODS: JASPER motif match analysis was used to identify the putative factors binding to SRR2 sequence. SRR2 probe pull-down assay and quantitate real-time PCR were performed to analyze the regulation of Sox2 transcriptional activity by MYC. Methylcellulose colony formation assay, chemoresistance to doxorubicin and mouse xenograft study were performed to investigate the biological functions of MYC. PCR array and western blotting were executed to study related signaling pathways that regulate MYC expression. Immunofluorescence and immunohistochemistry assay were initiated to evaluate the expression of MYC and its correlation with its regulator by chi-square test analysis in human primary tumor cells. RESULTS: We identified MYC as a potential regulator of RU/RR dichotomy. In support of its role, MYC was highly expressed in RR cells compared to RU cells, and inhibition of MYC substantially decreased the Sox2/SRR2 binding, Sox2 transcriptional activity, chemoresistance, and methylcellulose colony formation. In contrast, enforced expression of MYC in RU cells conferred the RR phenotype. The Wnt/ß-catenin pathway, a positive regulator of MYC, was highly active in RR but not RU cells. While inhibition of this pathway in RR cells substantially decreased MYC expression and SRR2 reporter activity, experimental activation of this pathway led to the opposite effects in RU cells. Collectively, our results support a model in which a positive feedback loop involving Wnt/ß-catenin/MYC and Sox2 contributes to the RR phenotype. In a mouse xenograft model, RU cells stably transfected with MYC showed upregulation of the Wnt/ß-catenin/MYC/Sox2 axis and increased tumorigenecity. Correlating with these findings, there was a significant correlation between the expression of active ß-catenin and MYC in ALK + ALCL primary tumor cells. CONCLUSIONS: A positive feedback loop involving the Wnt/ß-catenin/MYC/Sox2 axis defines a highly tumorigenic cell subset in ALK + ALCL.

Affinity maturation of a broadly neutralizing human monoclonal antibody that prevents acute hepatitis C virus infection in mice.

Direct-acting antivirals (DAAs) have led to a high cure rate in treated patients with chronic hepatitis C virus (HCV) infection, but this still leaves a large number of treatment failures secondary to the emergence of resistance-associated variants (RAVs). To increase the barrier to resistance, a complementary strategy is to use neutralizing human monoclonal antibodies (HMAbs) to prevent acute infection. However, earlier efforts with the selected antibodies led to RAVs in animal and clinical studies. Therefore, we identified an HMAb that is less likely to elicit RAVs for affinity maturation to increase potency and, more important, breadth of protection. Selected matured antibodies show improved affinity and neutralization against a panel of diverse HCV isolates. Structural and modeling studies reveal that the affinity-matured HMAb mediates virus neutralization, in part, by inducing conformational change to the targeted epitope, and that the maturated light chain is responsible for the improved affinity and breadth of protection. A matured HMAb protected humanized mice when challenged with an infectious HCV human serum inoculum for a prolonged period. However, a single mouse experienced breakthrough infection after 63 days when the serum HMAb concentration dropped by several logs; sequence analysis revealed no viral escape mutation. CONCLUSION: The findings suggest that a single broadly neutralizing antibody can prevent acute HCV infection without inducing RAVs and may complement DAAs to reduce the emergence of RAVs. (Hepatology 2016;64:1922-1933).

Validation of the Model of End-Stage Liver Disease for Liver Transplant Allocation in Alberta: Implications for Future Directions in Canada.

Background. Since 2002, the Model of End-Stage Liver Disease (MELD) has been used for allocation of liver transplants (LT) in the USA. In Canada, livers were allocated by the CanWAIT algorithm. The aim of this study was to compare the abilities of MELD, Child-Pugh (CP), and CanWAIT status to predict 3-month and 1-year mortality before LT in Canadian patients and to describe the use of MELD in Canada. Methods. Validation of MELD was performed in 320 patients listed for LT in Alberta (1998-2002). In October 2014, a survey of MELD use by Canadian LT centers was conducted. Results. Within 1 year of listing, 47 patients were removed from the waiting list (29 deaths, 18 too ill for LT). Using logistic regression, the MELD and CP were better than the CanWAIT at predicting 3-month (AUROC: 0.79, 0.78, and 0.59; p = 0.0002) and 1-year waitlist mortality (AUROC: 0.70, 0.70, and 0.55; p = 0.0023). Beginning in 2004, MELD began to be adopted by Canadian LT programs but its use was not standardized. Conclusions. Compared with the CanWAIT system, the MELD score was significantly better at predicting LT waitlist mortality. MELD-sodium (MELD-Na) has now been adopted for LT allocation in Canada.

Hepatitis C Virus-Induced Degradation of Cell Death-Inducing DFFA-Like Effector B Leads to Hepatic Lipid Dysregulation.

UNLABELLED: Individuals chronically infected with hepatitis C virus (HCV) commonly exhibit hepatic intracellular lipid accumulation, termed steatosis. HCV infection perturbs host lipid metabolism through both cellular and virus-induced mechanisms, with the viral core protein playing an important role in steatosis development. We have recently identified a liver protein, the cell death-inducing DFFA-like effector B (CIDEB), as an HCV entry host dependence factor that is downregulated by HCV infection in a cell culture model. In this study, we investigated the biological significance and molecular mechanism of this downregulation. HCV infection in a mouse model downregulated CIDEB in the liver tissue, and knockout of the CIDEB gene in a hepatoma cell line results in multiple aspects of lipid dysregulation that can contribute to hepatic steatosis, including reduced triglyceride secretion, lower lipidation of very-low-density lipoproteins, and increased lipid droplet (LD) stability. The potential link between CIDEB downregulation and steatosis is further supported by the requirement of the HCV core and its LD localization for CIDEB downregulation, which utilize a proteolytic cleavage event that is independent of the cellular proteasomal degradation of CIDEB. IMPORTANCE: Our data demonstrate that HCV infection of human hepatocytesin vitroandin vivoresults in CIDEB downregulation via a proteolytic cleavage event. Reduction of CIDEB protein levels by HCV or gene editing, in turn, leads to multiple aspects of lipid dysregulation, including LD stabilization. Consequently, CIDEB downregulation may contribute to HCV-induced hepatic steatosis.