Subunit composition of respiratory chain complex 1 and its responses to oxygen in mitochondria from human donor livers

OBJECTIVE: Donor liver function in transplantation is defined by mitochondrial function and the ability of mitochondria to recover from the sequence of warm and/or cold ischemia. Mitochondrial resilience maybe related to assembly and- subunit composition of Complex 1. The aim of this study was to determine if Complex 1 subunit composition was different in donor livers of varying quality and whether oxygen exposure had any effect. RESULTS: Five human livers not suitable for transplant were split. One half placed in cold static storage and the other half exposed to 40% oxygen for 2 h. Protein was extracted for western blot. Membranes were probed with antibodies against β-actin and the following subunits of Complex 1: MTND1, NDUFA10, NDUFB6 and NDUFV2. No difference in steady state Complex 1 subunit composition was demonstrated between donor livers of varying quality, in terms of steatosis or mode of donation. Neither did exposure to oxygen influence Complex 1 subunit composition. This small observational study on subunit levels suggest that Complex 1 is fully assembled as no degradation of subunits associated with the different parts of the enzyme was seen

Computational Analysis of Cholangiocarcinoma Phosphoproteomes Identifies Patient-Specific Drug Targets

Cholangiocarcinoma is a form of hepatobiliary cancer with an abysmal prognosis. Despite advances in our understanding of cholangiocarcinoma pathophysiology and its genomic landscape, targeted therapies have not yet made a significant impact on its clinical management. The low response rates of targeted therapies in cholangiocarcinoma suggest that patient heterogeneity contributes to poor clinical outcome. Here we used mass spectrometry–based phosphoproteomics and computational methods to identify patient-specific drug targets in patient tumors and cholangiocarcinoma-derived cell lines. We analyzed 13 primary tumors of patients with cholangiocarcinoma with matched nonmalignant tissue and 7 different cholangiocarcinoma cell lines, leading to the identification and quantification of more than 13,000 phosphorylation sites. The phosphoproteomes of cholangiocarcinoma cell lines and patient tumors were significantly correlated. MEK1, KIT, ERK1/2, and several cyclin-dependent kinases were among the protein kinases most frequently showing increased activity in cholangiocarcinoma relative to nonmalignant tissue. Application of the Drug Ranking Using Machine Learning (DRUML) algorithm selected inhibitors of histone deacetylase (HDAC; belinostat and CAY10603) and PI3K pathway members as high-ranking therapies to use in primary cholangiocarcinoma. The accuracy of the computational drug rankings based on predicted responses was confirmed in cell-line models of cholangiocarcinoma. Together, this study uncovers frequently activated biochemical pathways in cholangiocarcinoma and provides a proof of concept for the application of computational methodology to rank drugs based on efficacy in individual patients. SIGNIFICANCE: Phosphoproteomic and computational analyses identify patient-specific drug targets in cholangiocarcinoma, supporting the potential of a machine learning method to predict personalized therapies

Biliary complications after liver transplantation using grafts from donors after cardiac death: results from a matched control study in a single large volume center.

OBJECTIVE: To assess the incidence and impact of biliary complications in recipients transplanted from donors after cardiac death (DCD) at one single large institution. BACKGROUND: Shortage of available cadaveric organs is a significant limiting factor in liver transplantation (LT). The use of DCD offers the potential to increase the organ pool. However, early results with DCD liver grafts were associated with a greater incidence of ischemic cholangiopathy (IC), leading to several programs to abandoning this source of organs. METHODS: A retrospective analysis of a prospective database from April 2001 to 2010 focused on 167 consecutive DCD-LT. Each DCD transplant was matched with 2 brain death donors (DBD) grafts (n = 333) according to the period of transplantation. Primary outcome measures were biliary complications including the severity of complications, graft survival and patient survival. Minimum follow-up was 3 months. RESULTS: Anastomotic stricture was the most common biliary complication (DCD = 30, 19% vs. DBD = 41, 13%). Most were treated endocoscopically (grade IIIa = 72%), whereas hepatico-jejunostomy (grade IIIb) was performed in 22%. Primary IC occurred in 4 (2.5%) recipients from the DCD group and was absent in the DBD group (P = 0.005). However, none of these patients required retransplantation. Patient and graft survival at 1, 3, and 5 years were similar between DCD and DBD groups (P = 0.106, P = 0.138, P = 0.113, respectively). CONCLUSIONS: The encouraging results with DCD-LT are probably due to the selection of DCD grafts and clear definition of warm ischemia

Ischemic cholangiopathy in liver transplantation using donation after cardiac death donors: analysis of a matched control study in a single large volume center.

Background: Shortage of available organs is a limiting factor in liver transplantation (LT). The use of donors after cardiac death (DCD) offers potentials to increase the organ pool. The early results with DCD liver grafts were associated with a greater incidence of non-anastomotic biliary complications, leading to several programs to abandoning this source of organs. The UNOS data also raise concerns regarding DCD-LT results and the incidence of cholangiopathy. Aim: To assess the impact of cholangiopathy and biliary complications in DCD recipients at a single institution. Methods: A retrospective analysis from April 2001 to 2010 was undertaken focusing on 167 consecutive DCD-LT. Each DCD transplant was matched with two DBD (brain death donors) grafts (n=333) according to the period of transplantation. Primary outcome measures were biliary complications and ischemic cholangiopathy including the severity of complications, graft survival and patient survival. Results: The most common type among biliary complication was anastomotic stricture (DCD=30, 19% vs. DBD=41, 13%). Most of them were treated endocoscopically (grade IIIa=72%), while hepatico-jejunostomy (grade IIIb) was performed in 22%. Primary ischemic cholangiopathy occurred in 4 (2.5%) recipients from the DCD group, while such complication were absent in the DBD group (p=0.005). However, none of these patients required re-transplantation. Patient and graft survival at 1-, 3- and 5- years were similar between DCD and DBD groups (p=0.106, p=0.138, p=0.113 respectively). Conclusions: In contrast to previous reports, the incidence of ischemic cholangiopathy in DCD recipients was low, and has had no impact on graft or patient survival to-date. These encouraging results of DCD-LT are likely due to a stringent selection of DCD grafts and clear definition of warm ischemia