Interaction between tacrolimus, MELD score and acute kidney injury after liver transplantation. Analysis on a large contemporary bicenter meld-era series.

BACKGROUND: Acute kidney injury (AKI) after liver transplantation (LT) is a common problem with complex management. The aims were to analyze the profile of AKI-RIFLE categories in the post-transplant setting of a wide multicentre cohort of patients in the MELD era and to specifically determine the effect of tacrolimus-based (TACRO) immunosuppressive regimes on the development of AKI. METHODS: A retrospective analysis of 550 (2007-2012) consecutive patients transplanted at Reina Sofia, Cordoba, and King's College Hospital, London, was performed. Inclusion criterion was to have CNI as part of initial immunosuppression immediately after LT. RESULTS: After exclusion criteria, a total of 477 patients were analyzed. Incidence of AKI within the first 2 weeks after LT was 65.8% (AKI-Risk), 41.3% (AKI-Injury), and 12.3% (AKI-Failure). The development of any type of AKI had no impact on short- and/or long-term survival up to 3 years after the transplant. Moreover, AKI was almost universal in the early post-transplant period and TACRO trough concentrations during the first 2 weeks after the transplant were not predictors of AKI in none of its categories in the multivariate analyses. CONCLUSIONS: Low-TACRO-based regimes were not as useful as expected in the prevention of AKI when analyzed in the context of a large contemporary LT series.

Preliminary results from the use of intraoperative real-time biliary oxygen monitoring in liver transplantation.

BACKGROUND AND AIMS: Biliary anastomosis is a frequent area of complications after liver transplantation (LT) and a potential area of "microangiopathy". The concept of a "marginal bile duct" is unexplored. The main aim was to make a preliminary evaluation of the utility of an innovative real-time oxygen microtension (pO2mt) testing device for the assessment of bile duct viability during LT and to correlate these pO2mt values with microvascular tissue quality by histopathology and outcomes. PATIENTS AND METHODS: Observational prospective cohort study with 23 patients. Oxygen microtension measurements were made placing a micropO2 probe in different areas of recipient and donor's bile duct intraoperative. RESULTS: Mean pO2mt in the graft bile duct at the level of the anastomosis 103.82 (31-157) mm Hg, being 121.52 (55-174) mm Hg 1.5 cm proximal to the hilar plate (P < 0.001). Mean pO2mt in the recipient's bile duct was 117.87 (62-185) mm Hg, while a value of 137.30 (81-198) mm Hg was observed 1.5 cm distal to the anastomosis (P < 0.001). Cystic duct resection (12 cases) was also related with higher pO2mt values at anastomosis [117.8 (93-157) vs 88.54 (31-124) mm Hg] and distal to anastomosis [135.6 (111-174) vs 106.2 (55-133) mm Hg; P < 0.001]. Patients with 1-, 3-, and 12-month biliary complications had significantly lower pO2mt in the intraoperative measurements. CONCLUSION: Our preliminary results show that distal borders of donor and recipient bile ducts may be low-vascularized areas. Tissue pO2mt is significantly higher in areas close to the hilar plate and to the duodenum in donor and recipient's sides, respectively. Bile duct injury and biliary complications are associated with worse tissue pO2mt.

Identification of candidate biomarkers for hepatocellular carcinoma in plasma of HCV-infected cirrhotic patients by 2-D DIGE.

BACKGROUND: The current methods available for screening and detecting hepatocellular carcinoma (HCC) have insufficient sensitivity and specificity, and only a low percentage of diagnosis of small tumours is based on these assays. Because HCC is usually asymptomatic at potentially curative stages, identification of biomarkers for the early detection of HCC is essential to improve patient survival. AIM: The aim of this study was to identify candidate markers for HCC development in the plasma from hepatitis C virus (HCV)-infected cirrhotic patients. METHODS: We compared protein expression profiles of plasma samples from HCV-infected cirrhotic patients with and without HCC, using two-dimensional fluorescence difference gel electrophoresis (2-D DIGE) coupled with MALDI-TOF/TOF mass spectrometry. The 2-D DIGE results were analysed statistically using Decyder™ software, and verified by western blot and enzyme-linked immunosorbent assay (ELISA). RESULTS: In the plasma of HCV-infected HCC patients, we observed decreased expression of complement component 9, ficolin-3 (FCN3), serum amyloid P component (SAP), fibrinogen-gamma and immunoglobulin gamma-1 chain, and increased expression of vitronectin (VTN) and galectin-3 binding protein (G3BP) by DIGE analysis. ELISA confirmed DIGE results for VTN and G3BP but not for SAP or FCN3 in a larger patient population. CONCLUSIONS: The proteins VTN and SAP are candidate biomarkers for HCC development in HCV-infected cirrhotic patients.

Cardiotrophin-1 reduces ischemia/reperfusion injury during liver transplant.

BACKGROUND: Orthotopic liver transplantation (OLT) is currently the elective treatment for advanced liver cirrhosis and acute liver failure. Ischemia/reperfusion damage may jeopardize graft function during the postoperative period. Cardiotrophin-1 (CT-1) has demonstrated cytoprotective properties in different experimental models of liver injury. There is no evidence to demonstrate its potential use in the prevention of the ischemia/reperfusion injury that occurs during OLT. The present study is the first report to show that the administration of CT-1 to donors would benefit the outcome of OLT. MATERIALS AND METHODS: We tested the cytoprotective effect of CT-1 administered to the donor prior to OLT in an experimental pig model. Hemodynamic changes, hepatic histology, cell death parameters, activation of cell signaling pathways, oxidative and nitrosative stress, and animal survival were analyzed. RESULTS: Our data showed that CT-1 administration to donors increased animal survival, improved cardiac and respiratory functions, and reduced hepatocellular injury as well as oxidative and nitrosative stress. These beneficial effects, related to the activation of AKT, ERK, and STAT3, reduced caspase-3 activity and diminished IL-1ß and TNF-α expression together with IL-6 upregulation in liver tissue. CONCLUSIONS: The administration of CT-1 to donors reduced ischemia/reperfusion injury and improved survival in an experimental pig model of OLT.

Machine perfusion and the prevention of ischemic type biliary lesions following liver transplant: What is the evidence?

The widespread uptake of different machine perfusion (MP) strategies for liver transplant has been driven by an effort to minimize graft injury. Damage to the cholangiocytes during the liver donation, preservation, or early posttransplant period may result in stricturing of the biliary tree and inadequate biliary drainage. This problem continues to trouble clinicians, and may have catastrophic consequences for the graft and patient. Ischemic injury, as a result of compromised hepatic artery flow, is a well-known cause of biliary strictures, sepsis, and graft failure. However, very similar lesions can appear with a patent hepatic artery and these are known as ischemic type biliary lesions (ITBL) that are attributed to microcirculatory dysfunction rather than main hepatic arterial compromise. Both the warm and cold ischemic period duration appear to influence the onset of ITBL. All of the commonly used MP techniques deliver oxygen to the graft cells, and therefore may minimize the cholangiocyte injury and subsequently reduce the incidence of ITBL. As clinical experience and published evidence grows for these modalities, the impact they have on ITBL rates is important to consider. In this review, the evidence for the three commonly used MP strategies (abdominal normothermic regional perfusion [A-NRP], hypothermic oxygenated perfusion [HOPE], and normothermic machine perfusion [NMP] for ITBL prevention has been critically reviewed. Inconsistencies with ITBL definitions used in trials, coupled with variations in techniques of MP, make interpretation challenging. Overall, the evidence suggests that both HOPE and A-NRP prevent ITBL in donated after circulatory death grafts compared to cold storage. The evidence for ITBL prevention in donor after brain death grafts with any MP technique is weak.

Impact of age on liver regeneration response to injury after partial hepatectomy in a rat model.

BACKGROUND: Liver resection is a feasible treatment for multiple liver diseases. There is no evidence about the impact of age on liver regeneration. OBJECTIVE: To assess the effect of age on liver regeneration in an experimental in vivo animal model of 70%-partial hepatectomy. METHODS: Forty young (Y) and old (O) Wistar male rats (n = 80) were distributed into four groups [controls (C), sham operated (SO), hepatectomy 6 h (H6), and 48 h (H48)]. Different morphometric and biochemical factors, oxidative and nitrosative stress, lipid peroxidation, cytokines kinetics, and histopathologic tissular parameters were determined. RESULTS: Early postoperative mortality was higher in aged rats (P = 0.049). Morphometric determinations, liver regeneration index, and total volume weight were favorable to young rats. Serum transaminase levels were higher in aged rats. Parameters of necrosis (measured by histopathologic injury [HI: 0-I-II-III]), regeneration (measured by bromodeoxyuridine-BrdU incorporation) and apoptosis (determined by the TDT-mediated dUTP nick end labeling-TUNEL) were well-synchronized in young rats. Parameters of oxidative stress such as reduced (GSH), oxidized (GSSG) glutathione and lipid peroxidation (measured by hepatic malondialdehyde -MDA-) were lower in young animals throughout the studied period. Nitrosative stress measured by nitric oxide (NO) end-products was higher in late stages in resected old rats. Pro-inflammatory cytokines (TNF- α) reached higher and earlier levels in aged rats while pro-regenerative cytokines (IL-6) were significantly higher in early stages for young rats and in late stages for aged rats. The levels of TGF-ß were higher in young rats. CONCLUSION: Liver regeneration is delayed and reduced in aged animals submitted to liver resection.

Nitric oxide mimics transcriptional and post-translational regulation during α-tocopherol cytoprotection against glycochenodeoxycholate-induced cell death in hepatocytes.

BACKGROUND & AIMS: Reactive oxygen species (ROS) and nitric oxide (NO) exert a relevant role during bile acid-induced hepatotoxicity. Whether α-Tocopherol regulates oxidative and nitrosative stress, bile acid transporter expression and their NO-dependent post-translational modifications, and cell death were assessed in vitro and in vivo. METHODS: α-Tocopherol and/or NO donors (DETA-NONOate or CSNO, and V-PYRRO/NO) were administered to glycochenodeoxycholic acid (GCDCA)-treated cultured human hepatocytes or to bile duct obstructed rats. Cell injury, superoxide anion (O⁻2) production, as well as inducible nitric oxide synthase (NOS-2), cytochrome P4507A1 (CYP7A1), heme oxygenase-1, (HO-1) and bile acid transporter expression were determined. Cysteine S-nitrosylation and tyrosine nitration of Na(+)-taurocholate co-transporting polypeptide (NTCP), as well as taurocholic acid (TC) uptake were also evaluated. RESULTS: GCDCA-induced cell death was associated with increased (O⁻2) production, NTCP and HO-1 expression, and with a reduction of CYP7A1 and NOS-2 expression. α-Tocopherol reduced cell death, (O⁻2) production, CYP7A1, NTCP, and HO-1 expression, as well as increased NOS-2 expression and NO production in GCDCA-treated hepatocytes. α-Tocopherol and NO donors increased NTCP cysteine S-nitrosylation and tyrosine nitration, and reduced TC uptake in hepatocytes. α-Tocopherol and V-PYRRO/NO reduced liver injury and NTCP expression in obstructed rats. CONCLUSIONS: The regulation of CYP7A1, NTCP, and HO-1 expression may be relevant for the cytoprotective properties of α-Tocopherol and NO against mitochondrial dysfunction, oxidative stress and cell death in GCDCA-treated hepatocytes. The regulation of NO-dependent post-translational modifications of NTCP by α-Tocopherol and NO donors reduces the uptake of toxic bile acids by hepatocytes.

Extended criteria donors in liver transplant candidates with hepatorenal syndrome.

Hepatorenal syndrome (HRS) is a complication of cirrhosis with a poor prognosis without transplantation. The aim of this study is to analyze the influence of extended criteria donors (ECD) on the postoperative outcome of recipients with HRS. The last 498 patients were divided according to pre-transplant type 1 or 2 HRS. Sixty-six (13.25%) recipients fulfilled HRS criteria. Three-month graft survival was 84% with at-listing recipient serum creatinine ranging from 0-0.8 mg/dL; 80% with s-creatinine = 0.9-1.5 mg/dL; 79% with s-creatinine = 1.6-2.5 mg/dL; and 58% with s-creatinine >2.6 mg/dL (log-rank = 18.039; p = 0.001). Recipients with HRS presented higher levels of pre-transplant creatinine and lower levels of sodium, more episodes of hemodialysis and ascitis, and higher model of end-stage liver disease-scores. Three-month graft survival in recipients with HRS relative to ECD-variables showed differences in univariate analysis according to graft steatosis (85% in absent steatosis = 0-10%; 78% in mild steatosis = 10-30%; 76% in moderate steatosis = 30-60%; and 49% when severe steatosis >60%; log-rank = 5.146; p = 0.023). Cox-proportional-hazard-model revealed that graft macrosteatosis per-30%-increments (p = 0.000; HR = 1.303 [1.24-1.33] per-30%-increment) and donors >65 yr (p = 0.089; HR = 1.622 [1.17-1.94]) were independent predictors of graft loss in recipients with HRS. In conclusion, the use of ECD in recipients with cirrhosis and HRS is a good option. However, grafts from moderate-to-severe steatosis and those from aged donors must be carefully allocated in candidates with HRS.

Predictive Factors for Pulmonary Homograft Dysfunction After Ross Surgery: A 20-Year Follow-up.

BACKGROUND: We studied the determinants of hemodynamics and analyzed the incidence, risk factors, and clinical impact of pulmonary homograft dysfunction following Ross surgery, after a 20-year follow-up at our referral center. METHODS: From 1997 to 2017, a total of 142 patients underwent surgery using the Ross procedure. The development of moderate-severe stenosis (peak transhomograft pressure gradient 36 mm Hg or greater) and surgical or percutaneous Ross homograft reinterventions were evaluated by echocardiography in the immediate postoperative period and at annual intervals. RESULTS: After 20 years of follow-up, 31% of patients had moderate-severe homograft stenosis, and 9.1% had had to undergo one or two reinterventions, of which, six were valve replacements and seven were percutaneous interventions. At 1, 5, and 20 years, 89.4%, 74.6%, and 69% of these patients, respectively, were free from moderate-severe stenosis; and 99.3%, 95.7%, and 90.9%, respectively, had freedom from homograft reintervention. The pediatric group had a higher risk factor for homograft stenosis (hazard ratio 3.70; 95% confidence interval, 1.56 to 7.20, P = .002), whereas donor age behaved as a protective factor (hazard ratio 0.98; 95% confidence interval, 0.95 to 0.99; P = .044). Pulmonary homograft stenosis tended to appear in the first year (10.6%) or at 5 years (25.4%). CONCLUSIONS: Pulmonary homografts implanted in the Ross procedure offer satisfactory long-term results, but the level of homograft dysfunction is not negligible. Young recipient and donor age were associated with a higher rate of homograft stenosis during follow-up. Moreover, homograft dysfunction usually occurred during the first few years of follow-up, and may have been related to immune responses.

Results of a survey on peri-operative nutritional support in pancreatic and biliary surgery in Spain.

INTRODUCTION: Introduction: a survey on peri-operative nutritional support in pancreatic and biliary surgery among Spanish hospitals in 2007 showed that few surgical groups followed the 2006 ESPEN guidelines. Ten years later we sent a questionnaire to check the current situation. Methods: a questionnaire with 21 items sent to 38 centers, related to fasting time before and after surgery, nutritional screening use and type, time and type of peri-operative nutritional support, and number of procedures. Results: thirty-four institutions responded. The median number of pancreatic resections (head/total) was 29.5 (95% CI: 23.0-35; range, 5-68) (total, 1002); of surgeries for biliary malignancies (non-pancreatic), 9.8 (95% CI: 7.3-12.4; range, 2-30); and of main biliary resections for benign conditions, 10.4 (95% CI: 7.6-13.3; range, 2-33). Before surgery, only 41.2% of the sites used nutritional support (< 50% used any nutritional screening procedure). The mean duration of preoperative fasting for solid foods was 9.3 h (range, 6-24 h); it was 6.6 h for liquids (range, 2-12). Following pancreatic surgery, 29.4% tried to use early oral feeding, but 88.2% of the surveyed teams used some nutritional support; 26.5% of respondents used TPN in 100% of cases. Different percentages of TPN and EN were used in the other centers. In malignant biliary surgery, 22.6% used TPN always, and EN in 19.3% of cases. Conclusions: TPN is the commonest nutrition approach after pancreatic head surgery. Only 29.4% of the units used early oral feeding, and 32.3% used EN; 22.6% used TPN regularly after surgery for malignant biliary tumours. The 2006 ESPEN guideline recommendations are not regularly followed 12 years after their publication in our country.

INTRODUCCIÓN: Introducción: realizamos una encuesta sobre soporte nutricional perioperatorio en cirugía pancreática y biliar en hospitales españoles en 2007, que mostró que pocos grupos quirúrgicos seguían las guías de ESPEN 2006. Diez años después enviamos un cuestionario para comprobar la situación actual. Métodos: treinta y ocho centros recibieron un cuestionario con 21 preguntas sobre tiempo de ayunas antes y después de la cirugía, cribado nutricional, duración y tipo de soporte nutricional perioperatorio, y número de procedimientos. Resultados: respondieron 34 grupos. La mediana de pancreatectomías (cabeza/total) fue de 29,5 (IC 95%: 23,0-35; rango, 5-68) (total, 1002), la de cirugías biliares malignas de 9,8 (IC 95%: 7,3-12,4; rango, 2-30) y la de resecciones biliares por patología benigna de 10,4 (IC 95%: 7,6-13,3; rango, 2-33). Solo el 41,2% de los grupos utilizaban soporte nutricional antes de la cirugía (< 50% habian efectuado un cribado nutricional). El tiempo medio de ayuno preoperatorio para sólidos fue de 9,3 h (rango, 6-24 h), y de 6,6 h para líquidos (rango, 2-12). Tras la pancreatectomía, el 29,4% habían intentado administrar una dieta oral precoz, pero el 88,2% de los grupos usaron algún tipo de soporte nutricional y el 26,5% usaron NP en el 100% de los casos. Los demás grupos usaron diferentes porcentajes de NP y NE en sus casos. En la cirugía biliar maligna, el 22,6% utilizaron NP siempre y NE en el 19,3% de los casos. Conclusiones: la NP es el soporte nutricional más utilizado tras la cirugía de cabeza pancreática. Solo el 29,4% de las unidades usan nutrición oral precoz y el 32,3% emplean la NE tras este tipo de cirugía. El 22,6% de las instituciones usan NP habitualmente tras la cirugía de tumores biliares malignos. Las guías ESPEN 2006 no se siguen de forma habitual en nuestro país tras más de 10 años desde su publicación.

Impact of donor graft steatosis on overall outcome and viral recurrence after liver transplantation for hepatitis C virus cirrhosis.

The aim of this study was to determine the influence of donor graft steatosis on overall outcome, viral recurrence, and fibrosis progression in orthotopic liver transplantation (OLT) for hepatitis C virus (HCV) cirrhosis. One hundred twenty patients who underwent OLT for HCV cirrhosis between 1995 and 2005 were included in the study. Donor steatosis was categorized as absent (0%-10%; n = 40), mild (10%-30%; n = 32), moderate (30%-60%; n = 29), or severe (>60%; n = 19). A Cox multivariate analysis for marginal donor variables and a Model for End-Stage Liver Disease index were performed. Fibrosis evolution was analyzed in liver biopsies (fibrosis < 2 or > or =2) 3, 6, and 12 months post-OLT and in the late post-OLT period. Fifty-six grafts were lost (46%). The survival of the grafts was inversely proportional to donor liver steatosis: 82%, 72%, and 72% at 1, 2, and 3 years post-OLT in the absence of steatosis; 73%, 63%, and 58% with mild steatosis; 74%, 62%, and 43% with moderate steatosis; and 62%, 49%, and 42% with severe steatosis (P = 0.012). HCV recurrence was earlier and more frequent in recipients with steatosis > 30% (46% versus 32% at 3 months, P = 0.017; 58% versus 43% at 6 months, P = 0.020; 70% versus 56% at 12 months, P = 0.058; and 95% versus 69% at 3 years post-OLT, P = 0.0001). Graft survival was lower in alcoholic liver disease recipients versus HCV recipients when steatosis was >30% at 3, 6, and 12 months post-OLT (P = 0.042) but not when steatosis was <30% (P = 0.53). A higher fibrosis score was obtained 3 months post-OLT (P = 0.033), 6 months post-OLT (P = 0.306), 12 months post-OLT (P = 0.035), and in the late post-OLT period (P = 0.009). In conclusion, donor graft steatosis influences the outcome of OLT for HCV cirrhosis. HCV recurrence is more frequent and earlier in recipients of moderately and severely steatotic livers. Fibrosis evolution is higher when graft steatosis is >30%. OLT with >30% steatotic donor livers should be precluded in HCV recipients.

Alteration of S-nitrosothiol homeostasis and targets for protein S-nitrosation in human hepatocytes.

The liver is one organ clearly influenced by nitric oxide (NO), and acute and chronic exposure to this substance has been associated with distinct patterns of liver disease. Disruption or deregulation of S-nitrosothiol (SNO) signalling leads to impairment of cellular function and disease, and this study was aimed to identify potential targets for protein S-nitrosation during alteration of SNO homeostasis in human hepatocytes. Cells were treated with S-nitroso-L-cysteine (CSNO), an effective physiological nitrosothiol for delivering NO bioactivity to cells. Treatment with CSNO augmented the levels of S-nitrosoproteins detected both by chemiluminescence and the biotin switch method. CSNO treatment also increased S-nitrosoglutathione reductase (GSNOR) activity that returned SNO content to basal levels. This increased enzymatic activity was related to augmented levels of ADH-5 mRNA, the gene encoding for GSNOR in humans. In addition, the treatment with the SNO also increased cell death. Twenty S-nitrosoproteins were identified in CSNO-treated hepatocytes, including mitochondrial aldehyde dehydrogenase, protein disulphide isomerase, Hsp60, GRP75 and Raf kinase inhibitor protein. The identification in the S-nitrosatable proteome of proteins involved in metabolism, maintenance of cellular homeostasis and signalling points to the relevance of protein S-nitrosation to the physiology and pathophysiology of human hepatocytes.

Late hepatic artery pseudoaneurysm: a rare complication after resection of hilar cholangiocarcinoma.

We report an unusual pathological entity of a pseudoaneurysm of the right hepatic artery, which developed two years after the resection of a type II hilar cholangiocarcinoma and secondary to an excessive skeletonization for regional lymphadenectomy and neoadjuvant external-beam radiotherapy. After a sudden and massive hematemesis, a multidetector computed tomographic angiography (MDCTA) showed a hepatic artery pseudoaneurysm. Angiography with embolization of the pseudoaneurysm was attempted using microcoils with adequate patency of the hepatic artery and the occlusion of the pseudoaneurysm. A new episode of hematemesis 3 wk later revealed a partial revascularization of the pseudoaneurysm. A definitive interventional radiological treatment consisting of transarterial embolization (TAE) of the right hepatic artery with stainless steel coils and polyvinyl alcohol particles was effective and well-tolerated with normal liver function tests and without signs of liver infarction.

Conservative management of perforated duodenal diverticulum: a case report and review of the literature.

Duodenal diverticula are a relatively common condition. They are asymptomatic, unless they become complicated, with perforation being the rarest but most severe complication. Surgical treatment is the most frequently performed approach. We report the case of a patient with a perforated duodenal diverticulum, which was diagnosed early and treated conservatively with antibiotics and percutaneous drainage of secondary retroperitoneal abscesses. We suggest this method could be an acceptable option for the management of similar cases, provided that the patient is in good general condition and without septic signs.

Risk factors of early recurrence in retroperitoneal liposarcoma. / Factores de riesgo implicados en la recurrencia precoz del liposarcoma retroperitoneal.

INTRODUCTION: The aim of this study is to identify factors associated to recurrence and survival in primary retroperitoneal liposarcomas. METHODS: Prospective database of 35 patients with primary retroperitoneal liposarcoma treated 2004-2015 were retrospectively analyzed. Exclusion criteria were recurrent and metastatic tumors. Overall survival (OS) and disease-free survival were reviewed. Patient data were compared between patients with or without recurrence within 12 months after surgery. Risk factors were determined using logistic regression analysis. RESULTS: Five-year OS was 61.1%. One and three-year disease-free survival were 68.6% and 17.1% respectively. OS in the early recurrence group was 36.4 months compared with 43.2 months in the group without early recurrence (P=.011). Early recurrence was associated with a reduction in OS (HR=4.05; CI95%: 1.27-12.96; P=.018). Multifocality and microscopic positive margins R1 were associated with early recurrence. Histologic subtype, margin of resection, histologic grade and multifocality were factors associated with recurrence. Contiguously involved organ resection had a beneficial effect on early recurrence and was associated with an increase in disease-free survival and OS. Adjuvant treatments had no protective effect on recurrence. CONCLUSIONS: This study underlines the crucial role aggressive surgical approach in retroperitoneal Liposarcoma treatment, especially in those patients with histological characteristics that adversely the prognosis.

Cytoprotective properties of alpha-tocopherol are related to gene regulation in cultured D-galactosamine-treated human hepatocytes.

Vitamin E (alpha-tocopherol) has demonstrated antioxidant activity and gene-regulatory properties. d-Galactosamine (D-GalN)-induced cell death is mediated by nitric oxide in hepatocytes, and it is associated with hepatic steatosis. The beneficial properties of alpha-tocopherol and their relation to oxidative stress and gene regulation were assessed in D-GalN-induced cell death. Hepatocytes were isolated from human liver resections by a collagenase perfusion technique. alpha-Tocopherol (50 microM) was administered at the advanced stages (10 h) of D-GalN-induced cell death in cultured hepatocytes. Cell death, oxidative stress, alpha-tocopherol metabolism, and NF-kappaB-, pregnane X receptor (PXR)-, and peroxisome proliferator-activated receptor (PPAR-alpha)-associated gene regulation were estimated in the hepatocytes. D-GalN increased cell death and alpha-tocopherol metabolism. alpha-Tocopherol exerted a moderate beneficial effect against apoptosis and necrosis induced by D-GalN. Induction (rifampicin) or inhibition (ketoconazole) of alpha-tocopherol metabolism and overexpression of PXR showed that the increase in PXR-related CYP3A4 expression caused by alpha-tocopherol enhanced cell death in hepatocytes. Nevertheless, the reduction in NF-kappaB activation and inducible nitric oxide synthase expression and the enhancement of PPAR-alpha and carnitine palmitoyl transferase gene expression by alpha-tocopherol may be relevant for cell survival. In conclusion, the cytoprotective properties of alpha-tocopherol are mostly related to gene regulation rather than to antioxidant activity in toxin-induced cell death in hepatocytes.

S-Nitrosation of proteins during D-galactosamine-induced cell death in human hepatocytes.

Nitric oxide (NO) participates in the cell death induced by d-Galactosamine (d-GalN) in hepatocytes, and NO-derived reactive oxygen intermediates are critical contributors to protein modification and hepatocellular injury. It is anticipated that S-nitrosation of proteins will participate in the mechanisms leading to cell death in d-GalN-treated human hepatocytes. In the present study, d-GalN-induced cell death was related to augmented levels of NO production and S-nitrosothiol (SNO) content. The biotin switch assay confirmed that d-GalN increased the levels of S-nitrosated proteins in human hepatocytes. S-nitrosocysteine (CSNO) enhanced protein S-nitrosation and altered cell death parameters that were related to S-nitrosation of the executioner caspase-3. Fifteen S-nitrosated proteins participating in metabolism, antioxidative defense and cellular homeostasis were identified in human hepatocytes treated with CSNO. Among them, seven were also identified in d-GalN-treated hepatocytes. The results here reported underline the importance of the alteration of SNO homeostasis during d-GalN-induced cell death in human hepatocytes.