Natural variations of copper and sulfur stable isotopes in blood of hepatocellular carcinoma patients.

The widespread hypoxic conditions of the tumor microenvironment can impair the metabolism of bioessential elements such as copper and sulfur, notably by changing their redox state and, as a consequence, their ability to bind specific molecules. Because competing redox state is known to drive isotopic fractionation, we have used here the stable isotope compositions of copper ((65)Cu/(63)Cu) and sulfur ((34)S/(32)S) in the blood of patients with hepatocellular carcinoma (HCC) as a tool to explore the cancer-driven copper and sulfur imbalances. We report that copper is (63)Cu-enriched by ∼0.4‰ and sulfur is (32)S-enriched by ∼1.5‰ in the blood of patients compared with that of control subjects. As expected, HCC patients have more copper in red blood cells and serum compared with control subjects. However, the isotopic signature of this blood extra copper burden is not in favor of a dietary origin but rather suggests a reallocation in the body of copper bound to cysteine-rich proteins such as metallothioneins. The magnitude of the sulfur isotope effect is similar in red blood cells and serum of HCC patients, implying that sulfur fractionation is systemic. The (32)S-enrichment of sulfur in the blood of HCC patients is compatible with the notion that sulfur partly originates from tumor-derived sulfides. The measurement of natural variations of stable isotope compositions, using techniques developed in the field of Earth sciences, can provide new means to detect and quantify cancer metabolic changes and provide insights into underlying mechanisms.

Human hepatocarcinoma-intestine-pancreas/pancreatitis-associated protein cures fas-induced acute liver failure in mice by attenuating free-radical damage in injured livers.

UNLABELLED: Acute liver failure (ALF) is a rare syndrome with a difficult clinical management and a high mortality rate. During ALF, several molecular pathways governing oxidative stress and apoptosis are activated to induce massive tissue injury and suppress cell proliferation. There are few anti-ALF drug candidates, among which is the C-type lectin Reg3α, or human hepatocarcinoma-intestine-pancreas/pancreatitis-associated protein (HIP/PAP), which displayed promising properties for tissue regeneration and protection against cellular stress in transgenic mice. We report on substantial preclinical and clinical advances in the development of a recombinant (rc) full-length human HIP/PAP protein as an anti-ALF drug. The curative effects and mechanisms of action of rcHIP/PAP were investigated in murine Fas-induced ALF. Primary hepatocytes were cultured with cytotoxic doses of tumor necrosis factor α/actinomycin-D, transforming growth factor ß, agonistic Fas antibody or hydrogen peroxide, and various concentrations of rcHIP/PAP. Cell viability, proliferation index, apoptosis, and oxidation were monitored. We found that rcHIP/PAP significantly improved survival in Fas-intoxicated mice in a dose-dependent and time-dependent manner, with optimum effects when it was injected at advanced stages of ALF. Primary hepatocytes were efficiently protected against multiple cell death signals by rcHIP/PAP. This survival benefit was linked to a depletion of oxidized biomolecules in injured liver cells due to a strong reactive oxygen species scavenging activity of rcHIP/PAP. Clinically, an escalating dose phase 1 trial demonstrated a good tolerability and pharmacokinetic profile of rcHIP/PAP in healthy subjects. CONCLUSION: The rcHIP/PAP protein exhibited significant curative properties against ALF in mice. It is a free-radical scavenger that targets a broad spectrum of death effectors and favors liver regeneration. The good safety profile of rcHIP/PAP during a phase 1 trial encourages evaluation of its efficacy in patients with ALF.

Immediate neuroendocrine signaling after partial hepatectomy through acute portal hyperpressure and cholestasis.

BACKGROUND & AIMS: Early neuroendocrine pathways contribute to liver regeneration after partial hepatectomy (PH). We investigated one of these pathways involving acute cholestasis, immediate portal hyperpressure, and arginine vasopressin (AVP) secretion. METHODS: Surgical procedure (PH, Portal vein stenosis (PVS), bile duct ligation (BDL), spinal cord lesion (SCL)) and treatments (capsaicin, bile acids (BA), oleanolic acid (OA)) were performed on rats and/or wild type or TGR5 (GPBAR1) knock-out mice. In these models, the activation of AVP-secreting supraoptic nuclei (SON) was analyzed, as well as plasma BA, AVP, and portal vein pressure (PVP). Plasma BA, AVP, and PVP were also determined in human living donors for liver transplantation. RESULTS: Acute cholestasis (mimicked by BDL or BA injection) as well as portal hyperpressure (mimicked by PVS) independently activated SON and AVP secretion. BA accumulated in the brain after PH or BDL, and TGR5 was expressed in SON. SON activation was mimicked by the TGR5 agonist OA and inhibited in TGR5 KO mice after BDL. An afferent nerve pathway also contributed to post-PH AVP secretion, as capsaicin treatment or SCL resulted in a weaker SON activation after PH. CONCLUSIONS: After PH in rodents, acute cholestasis and portal hypertension, via the nervous and endocrine routes, stimulate the secretion of AVP that may protect the liver against shear stress and bile acids overload. Data in living donors suggest that this pathway may also operate in humans.

The etiology of liver damage imparts cytokines transforming growth factor beta1 or interleukin-13 as driving forces in fibrogenesis.

UNLABELLED: It is unknown whether transforming growth factor beta1 (TGF-beta1) signaling uniformly participates in fibrogenic chronic liver diseases, irrespective of the underlying origin, or if other cytokines such as interleukin (IL)-13 share in fibrogenesis (e.g., due to regulatory effects on type I pro-collagen expression). TGF-beta1 signaling events were scored in 396 liver tissue samples from patients with diverse chronic liver diseases, including hepatitis B virus (HBV), hepatitis C virus (HCV), Schistosoma japonicum infection, and steatosis/steatohepatitis. Phospho-Smad2 staining correlated significantly with fibrotic stage in patients with HBV infection (n = 112, P < 0.001) and steatosis/steatohepatitis (n = 120, P < 0.01), but not in patients with HCV infection (n = 77, P > 0.05). In tissue with HBx protein expression, phospho-Smad2 was detectable, suggesting a functional link between viral protein expression and TGF-beta1 signaling. For IL-13, immunostaining correlated with fibrotic stage in patients with HCV infection and steatosis/steatohepatitis. IL-13 protein was more abundant in liver tissue lysates from three HCV patients compared with controls, as were IL-13 serum levels in 68 patients with chronic HCV infection compared with 20 healthy volunteers (72.87 +/- 26.38 versus 45.41 +/- 3.73, P < 0.001). Immunohistochemistry results suggest that IL-13-mediated liver fibrogenesis may take place in the absence of phospho-signal transducer and activator of transcription protein 6 signaling. In a subgroup of patients with advanced liver fibrosis (stage > or =3), neither TGF-beta nor IL-13 signaling was detectable. CONCLUSION: Depending on the cause of liver damage, a predominance of TGF-beta or IL-13 signaling is found. TGF-beta1 predominance is detected in HBV-related liver fibrogenesis and IL-13 predominance in chronic HCV infection. In some instances, the underlying fibrogenic mediator remains enigmatic.

Hepatocellular carcinoma is associated with an increased risk of hepatitis B virus recurrence after liver transplantation.

BACKGROUND & AIMS: Hepatitis B virus (HBV) recurrence after orthotopic liver transplantation (OLT) is significantly reduced by prophylaxis with hyperimmune antibody to hepatitis B surface antigen (anti-HBs) globulins (HBIG) and antiviral drugs. The role of hepatocellular carcinoma (HCC) in HBV recurrence remains unclear. We investigated the association between HCC pre-OLT and HBV recurrence post-OLT. METHODS: We studied 99 hepatitis B surface antigen-positive patients who underwent OLT for cirrhosis. The median follow-up period was 43 months. All patients received HBIG, and 51 also received lamivudine and/or adefovir. Of these 99 patients, 31 had HCC before OLT. Total HBV DNA and covalently closed circular (ccc)-DNA were measured in tumor and nontumor tissues from the explanted livers of 16 of these 31 HCC patients and, also, in a context of tumor recurrence, in 3 patients who developed HBV/HCC recurrence. RESULTS: Fourteen patients (14.1%) developed HBV recurrence within a median period of 15 months post-OLT. HCC at OLT, a pre-OLT HBV DNA viral load > or = 100,000 copies/mL, and HBIG monoprophylaxis were independently associated with HBV recurrence post-OLT. Eleven out of the 31 patients with HCC at OLT presented with HBV recurrence and 3 out of the 68 patients without HCC had HBV recurrence (P < .0001). HBV recurrence was more frequent in patients who developed HCC recurrence (7/8 patients, 87.5%) than in those who did not (4/23 patients, 17.4%) (P < .0001). In the 16 explanted livers, cccDNA was detectable in HCC cells in 11 and in nontumor cells in 12. cccDNA was detected in a context of HCC recurrence in 2 of the 3 patients tested who developed HBV/HCC recurrence. CONCLUSIONS: The associations of HCC pre-OLT, and HCC recurrence with HBV recurrence post-OLT, and the detection of HBV DNA and cccDNA in HCC suggest that HBV replication in tumor cells may contribute to HBV recurrence post-OLT.

Neurological improvement during bioartificial liver sessions in patients with acute liver failure awaiting transplantation.

BACKGROUND: Brain edema is the main cause of death in acute liver failure patients awaiting transplantation. We assessed the HepatAssist 2000, a liver-assist system containing porcine hepatocytes, as a bridge to transplantation in patients with acute liver failure. METHODS: Thirteen patients suffering from acute liver failure with criteria for transplantation entered an open baseline-controlled study, with liver-assist treatment sessions at 24-hr intervals until transplantation. Neurological status was regularly evaluated using the Glasgow Coma Scale. RESULTS: Three patients were not treated: one had an immediate transplantation and two improved spontaneously. Ten patients received one to three courses of HepatAssist. A significant neurological improvement (mean Glasgow Coma Scale before and after treatment: 6.5+/-3.7 and 9.6+/-4.4, respectively, P<0.02) was observed, which was related to the volume of plasma processed per square meter of body surface. A significant decrease was observed in mean levels of bilirubin (P=0.0005) and transaminases but not in the other indicators of liver function. Six patients had transient episodes of hemodynamic instability, and five had bleeding complications. Two patients died after transplantation. Eight patients survived with a mean follow-up of 24.3 (18-32) months. CONCLUSION: The HepatAssist 2000 is well tolerated, improves cerebral function, and may be used as a bridge to transplantation for patients with liver failure.

Could post-liver transplantation course be helpful for the diagnosis of so called cryptogenic cirrhosis?

Cryptogenic cirrhosis (CC) is diagnosed in 5-30% of cirrhotic patients overall and 7% of patients who undergo liver transplantation for cirrhosis. In our series of patients transplanted for CC, pre-transplant clinical and histological data and the post-transplant course were reexamined in an attempt to identify the aetiology. Among the 881 patients transplanted in our centre between 1987 and 2000, 28 patients with a median age of 46 yr (range: 18-69) at transplantation were initially classified as having CC. Two patients were excluded because of intense ischaemic lesions caused by chemoembolization prevented histological analysis of the native liver (n = 1) and because of cryptic HBV infection (n = 1). Among the remaining 26 patients, four groups were individualized: (i) patients with chronic inflammatory liver disease with autoimmune features (n = 14, 54%); (ii) patients with features suggestive of non-alcoholic fatty liver disease (n = 3, 11.5%); (iii); patients with incomplete septal cirrhosis (ISC) and vascular liver disease (n = 3), and (iv) patients with unresolved CC (n = 6, 23%). In the autoimmune liver disease group, the median International Autoimmune Hepatitis score was 12.5 (range: 11-19) after reevaluation and review of the post-transplantation course was helpful to confirm the diagnosis with the occurrence of active graft hepatitis in nine patients, with autoantibodies in five patients. The vascular group was characterized by lesions of obliterative portal venopathy and ISC in all native livers. Diagnosis of NAFLD was based on the clinical background of obesity and/or type 2 diabetes and the presence of steatosis or steatohepatitis in native livers and graft biopsies. A definite aetiological diagnosis can be achieved in the majority of patients initially diagnosed with CC. Autoimmune liver disease emerged as the main aetiology (14 of 26 patients, 54%) and frequently recurred on the grafted liver (nine cases). In all cases a precise diagnosis is obviously of practical interest for better management of post-transplant survey and treatment.

Hepatitis C virus viral recurrence and liver mitochondrial damage after liver transplantation in HIV-HCV co-infected patients.

BACKGROUND/AIMS: As life expectancy in HIV-HCV co-infected patients improves, end stage liver disease requiring liver transplantation (LT) may become an emerging problem. We report the Paul Brousse Hospital experience of transplantation for end stage cirrhosis in HIV-HCV co-infected patients. METHODS: Seven consecutive HIV-HCV co-infected patients were transplanted between December 1999 and December 2002 for end stage liver disease due to HCV. All patients were treated by highly active antiretroviral therapy (HAART), HIV plasma viral load was <400 copies/ml and median CD4 lymphocyte count was 306 cells/mm3 (range, 103-510) before LT. At the time of evaluation (March 2003), the median follow-up was 21 months (range, 4-40). RESULTS: Two patients died, 4 and 22 months, respectively after LT. At the last biopsy, METAVIR score was staged F4 in two patients, F3 in two, and F1 in one. Microvesicular steatosis was noted in nearly all patients. The ratio of mitochondrial to nuclear DNA was low in three of four patients examined as compared with the amount of liver mtDNA found in eight HIV-negative, HCV-infected controls (P=0.01). CONCLUSIONS: A significant defect in the activity of the respiratory chain complex IV was noted in all five patients studied. Mitochondrial hepatotoxicity and severe HCV recurrence occur in HIV-HCV co-infected patients after LT.