[show abstract][hide abstract] ABSTRACT: BACKGROUND: Genetic factors implicated in the pathogenesis of non-alcoholic fatty liver disease are poorly understood. Our aim was to characterize three genes involved in a rat model of non-alcoholic fatty liver disease and investigate the effect of rosiglitazone and bezafibrate. METHOD: Five rats were fed a chow diet (controls) and 18 a fructose-enriched diet (FED) for 5 weeks: 6 were administered rosiglitazone and 6 bezafibrate during the last 2 weeks and 6 were not treated at all. Livers were examined by reverse transcription-PCR for the genes encoding peroxisome proliferator-activated receptors (PPAR), PPAR-alpha, PPAR-gamma, and Mn superoxide dismutase2 (Mn SOD2). Western blot was used for proteins levels.Result: The FED rats showed a decrease in mRNA of MnSOD2, PPAR-alpha, and PPAR-gamma (3, 3.5 fold, and 27%, respectively) (p<0.05). The 3 genes normalized in response to rosiglitazone and bezafibrate. The proteins of MnSOD2, PPAR-alpha and PPAR-gamma in the FED rats decreased (2.5, 2, and 2.2, respectively) (p<0.05). Following administration of rosiglitazone, proteins of MnSOD2, PPAR-alpha and PPAR-gamma in the FED rats increased (reaching 1.5-fold, a 20% increase and normalization, respectively), (p<0.05). Administration of bezafibrate to the FED rats restored the proteins of 3 genes to baseline. CONCLUSION: A consistent reduction in hepatic expression of MnSOD2, PPAR-alpha and PPAR-gamma in the FED rats compared with controls was observed. Administration of either rosiglitazone or bezafibrate to the FED rats restored these genes to a pre-morbid state.
Lipids in Health and Disease 03/2013; 12(1):41. · 2.02 Impact Factor
[show abstract][hide abstract] ABSTRACT: Background Telomeres are non-coding regions of DNA that cap the ends of chromosomes. Their length is considered a marker of human replicative senescence and premature aging. Given the high association of liver transplantation with the metabolic syndrome, we hypothesized that liver transplant recipients may exhibit premature and accelerated aging. Material and Methods Telomere length in peripheral blood lymphocytes was measured by polymerase chain reaction in 62 consecutive liver-transplant recipients and 59 healthy control subjects aged 20-76 years. Clinical and laboratory parameters were collected from the medical files. Results The liver transplant recipients were significantly older than the control subjects (p=0.012), with significantly higher rates of obesity (BMI >30 kg/m2), dyslipidemia, hypertension, diabetes, and fatty liver. Mean telomere length was significantly shorter in the transplant group (0.59±0.6 vs. 1.91±1.78 in the controls, p<0.0001). Within the transplant group, there was no significant association between mean telomere length and underlying liver disease or presence of the metabolic syndrome or its constituents. On multivariate analysis, telomere length was negatively associated with patient age (p=0.0001), male sex (p=0.04), acute rejection (p=0.005), and fatty liver (p=0.009), and was positively associated with time from transplantation (p=0.006). Conclusions Liver transplantation is associated with shortened telomere length in peripheral blood lymphocytes, suggesting accelerated senescence.
Annals of transplantation : quarterly of the Polish Transplantation Society. 01/2013; 18:567-75.
[show abstract][hide abstract] ABSTRACT: Toll-like receptor 4 (TLR4) is expressed on hepatic non-parenchymal cells and hepatocytes. Hepatic signaling through TLR4 is critical in the pathogenesis of ischemia reperfusion injury (IRI) and leads to the release of cytokines. The role of bone marrow-derived TLR4 in the early reperfusion stage is unclear.
We used wild type mice (WT), TLR4deficient (TLR4ko) mice and chimeras to dissociate between the role of TLR4 expression in the liver (TLR4ko/WT) and in the immuno-hematopoietic system (WT/TLR4ko) in mouse hepatic IR injury model. Mice were subjected to in vivo partial IRI (70% for 60 min).
Compared with WT IR livers, TLR4ko IRI mice (4 hours) showed a significant reduction in serum liver enzyme, hepatic TNF-α and interleukin-1β levels. Fewer apoptotic hepatocytes cells were identified by morphological criteria and immunohistochemistry for caspase-3. In TLR4ko mice, decreased hepatic CJUN and NF-ĸB expression during IRI was noted compared with WT mice. Chimeric mice having either TLR4 bone-marrow or non-bone marrow derived cells following IRI exhibited almost similar hepatic injury as WT mice in the immediate reperfusion stage. CONCLUSIOn: Both TLR4 bone marrow-derived and non-bone marrow-derived cells are necessary in the initial process of hepatic injury. Activating TLR4-dependent signaling is required for IRI. The absence of the TLR4 gene plays a pivotal role in reducing hepatic IR injury.
Cellular Physiology and Biochemistry 07/2012; 30(2):489-98. · 3.42 Impact Factor
[show abstract][hide abstract] ABSTRACT: Liver transplantation is often associated with metabolic derangements. Adipocyte fatty-acid-binding protein 4 (AFABP4) integrates inflammatory and metabolic responses. It has also been associated with metabolic syndrome in animal models and clinical studies in the general population.
To determine the role of AFABP4 in post-transplant metabolic syndrome.
Consecutive patients followed for at least 6 months after liver transplantation were tested for insulin resistance by homeostasis model assessment (HOMA). Serum levels of AFABP4 were tested by an enzyme-linked immunosorbent assay.
The study group included 76 patients (64.5% male, mean age 56.3 ± 12.4 years). Hypertension was present in 56.5%, hyperlipidemia in 69.7%, diabetes mellitus in 23.6%. Half of the patients met at least 3 criteria for metabolic syndrome. Serum AFABP4 levels (p < 0.0001), HOMA index ≥ 2.5 vs. < 2.5 (p < 0.0002) and BMI ≥ 30 vs. < 30 (p < 0.0006) were significantly higher in patients with metabolic syndrome. Within the metabolic syndrome subgroup, AFABP4 levels significantly correlated with age, aspartate aminotransaminase level, waist circumference, and HOMA index. High AFABP4 significantly increased the odds of acquiring metabolic syndrome (OR 1.04, 95% CI 1.007-1.074, p = 0.017). On multiple logistic regression analysis, independent predictors of high AFABP4 were cryptogenic liver disease, steroid administration, high HOMA index, and a high degree of fatty infiltration.
Prevalence of metabolic syndrome is significantly higher in liver transplant recipients than in the general population. AFABP4 may serve as a circulating biomarker in the clinical prediction/diagnosis of metabolic syndrome in patients post-liver transplantation.
Annals of hepatology: official journal of the Mexican Association of Hepatology 05/2012; 11(3):343-9. · 1.67 Impact Factor
[show abstract][hide abstract] ABSTRACT: Squamous cellular carcinoma antigen (SCCA) is overexpressed in hepatocellular carcinoma (HCC) tissue and in sera of HCC patients. Our aim was to assess hepatic SCCA immunostaining in a series of HCCs and to correlate its presence with cell proliferation, apoptosis and clinical outcome.
Sixty-one HCC patients were included. Liver specimens were obtained either by biopsy (n = 17) or surgically (resection 27, transplantation 17). Immunostaining for AFP, Ki-67, SCCA and TUNEL assay were performed.
SCCA staining was detected in 83.6% of specimens. A statistical significant correlation was found between negative SCCA staining and mortality (p = 0.026) and a higher immunostaining score for Ki67 (p = 0.017). Positive SCCA staining was associated with well and moderate differentiated tumors (p = 0.022). Using multiple logistic regression analysis, Ki67 and TUNEL assay were found to be significant independent predictors of negative SCCA immunostaining. The area under the receiver operator characteristic curve was 0.87. Kaplan-Meier survival analysis revealed a significant difference between the patient group with positive versus negative SCCA immunostaining relating to survival time (p = 0.0106). Cox proportional hazard regression analysis demonstrated that Ki67 immunostaining and liver transplantation or resection were independently associated with mortality.
SCCA is overexpressed in HCC. SCCA status is associated with cell proliferation, apoptosis and survival. SCCA and Ki67 staining can predict survival. Our study results support a potential association of negative SCCA expression with other markers of poor outcome in HCC. More studies are needed to clarify the role of SCCA in HCC and expand the knowledge of the SCCA antigen in HCC patients.
[show abstract][hide abstract] ABSTRACT: Liver transplantation is the only therapy of proven benefit in fulminant hepatic failure (FHF). Lipopolysaccharide (LPS), d-galactosamine (GalN)-induced FHF is a well-established model of liver injury in mice. Erythropoietin has a powerful tissue-protective effect in animal models. The aim of this study was to investigate the effect and mechanism of recombinant human erythropoietin (rhEPO) administration in FHF mice.
C57BL/6 (n=42) mice were studied in vivo in a fulminant model induced by GalN/LPS. rhEPO was administered 30 min after the induction of FHF. Serum liver enzymes and hepatic tumor necrosis factor (TNF)-α and interleukin (IL)-1β levels were determined. Histologic analysis was performed, and apoptotic cells were identified by immunohistochemistry for caspase-3. Nuclear factor (NF)-κB and c-Jun-N-terminal kinase (JNK) activation were studied using Western blot analysis.
After the induction of FHF, all control mice died within 12 hr of GalN/LPS administration. However, 83% of mice that were administered rhEPO were alive 2 weeks later, and overall survival improved (Kaplan-Meier, P<0.001). The serum liver enzymes, hepatic TNF-α and IL-1β levels, liver histologic injury, and apoptotic hepatocytes were significantly reduced in FHF mice that were administered rhEPO compared with untreated mice. A significant decrease in hepatic NF-κB and JNK activation was noted in FHF rhEPO-treated mice compared with FHF untreated mice.
The administration of rhEPO brought about increased survival and attenuation of the hepatic injury. This was associated with decreased hepatic NF-κB and JNK activation and thus TNF-α and IL-1β levels. These findings have important implications for the potential use of rhEPO in FHF.
[show abstract][hide abstract] ABSTRACT: Ischemia-reperfusion injury (I/R) is the main cause of primary graft nonfunction. Our aim was to evaluate the effect of excessive versus acute administration of erythropoietin (EPO) in attenuating the hepatic injury induced by I/R in mice. The effect of segmental (70%) hepatic ischemia was evaluated in a transgenic mouse line with constitutive overexpression of human EPO cDNA and in wild-type (WT) mice. Mice were randomly allocated to 5 main experimental groups: (i) WT-sham, (ii) WT ischemia, (iii) WT ischemia + recombinant human erythropoietin (rhEPO), (iv) transgenic-sham, and (v) transgenic ischemia. The EPO-pretreated mice showed a significant reduction in liver enzyme levels and intrahepatic caspase-3 activity and fewer apoptotic hepatocytes (p < 0.05 for all) compared with the WT untreated I/R group. EPO decreased c-Jun N-terminal kinase (JNK) phosphorylation and nuclear factor-κB (NF-κB) expression during I/R. In transgenic I/R livers, baseline histology showed diffused hepatic injury, and no significant beneficial effect was noted between the WT untreated and the transgenic I/R mice. In conclusion, acute pretreatment with EPO in WT mice attenuated in vivo I/R liver injury. However, in excessive EPO overexpression, the initial liver injury abolished the beneficial effect of EPO. These findings have important implications for the potential use of acute EPO in I/R injury during liver transplantation.
Canadian Journal of Physiology and Pharmacology 12/2010; 88(12):1130-7. · 1.56 Impact Factor
[show abstract][hide abstract] ABSTRACT: The only currently offered curative option for many patients with primary or secondary liver tumors is the resection of hepatic tumors. The aim of this study was to evaluate the role of recombinant human erythropoietin (rhEPO) in liver protection and regeneration after subtotal hepatectomy in rats. Rats undergoing 70% hepatectomy received an intraperitoneal injection of saline (control) or rhEPO (4 U/g) 30 minutes prior to resection. Liver function was assessed by the measurement of the international normalized ratio (INR) levels, and hepatic injury was assessed by serum alanine aminotransferase and aspartate aminotransferase levels. Hepatic apoptosis was assessed by intrahepatic caspase-3 activity and morphological criteria. The regeneration capacity of remnant livers was assessed over 7 days with the regenerated liver/body weight ratio, immunohistochemistry markers of cell proliferation (Ki-67) and angiogenesis (von Willebrand factor), and phosphorylated extracellular signal-regulated kinase signaling. Two and 4 days after subtotal hepatectomy, the regenerated liver/body weight ratio was significantly higher in animals treated with rhEPO versus the control group (P < 0.005). Serum liver enzymes and INR levels on days 2 and 4 post-hepatectomy were significantly lower in animals pretreated with rhEPO in comparison with the control group (P < 0.005). No statistically significant difference was noted in intrahepatic hepatic caspase-3 activity, immunohistochemistry for caspase-3, or a terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling assay between the hepatectomized groups. In the rhEPO-pretreated group, the mitotic index, Ki-67 and von Willebrand factor expression, and extracellular signal-regulated kinase activity were significantly higher on day 2 post-hepatectomy (P < 0.05) in comparison with the control group. In conclusion, rhEPO treatment may offer a unique beneficial dual-function strategy for hepatic protection and regeneration immediately after subtotal hepatectomy in rats.
[show abstract][hide abstract] ABSTRACT: Late-onset symptoms of urea-cycle disorder may lead to a life-threatening disease which is often undetected. We report the clinical and metabolic manifestations of acute hyperammonemic encephalopathy in a 47-year-old asymptomatic man with ornithine transcarbamylase (OTC) deficiency. The hyperammonemic encephalopathy was unmasked by a high-protein Atkins diet.
Genetic analysis of the patient's family, 89 unrelated Ashkenazi Jewish and 50 unrelated Europeans subjects was performed using polymerase chain reaction amplification and DNA sequencing of the OTC gene.
Treatment with hemodialysis, provision of adequate calories to prevent catabolism, and protein elimination for 24h followed by protein restriction and ammonia scavenging medications effectively lowered the patient's plasma ammonia level and resulted in full recovery. Genetic analysis of the OTC gene revealed a novel hemizygous missense mutation in exon 5 (c.477T>G), leading to an isoleucine-to-methionine substitution in codon 159 (Ile159Met). Further genetic analysis of the patient's family yielded the mutation in many of them, although findings were negative in 89 unrelated Ashkenazi Jewish and 50 unrelated Europeans subjects.
This is the first reported case of an adult urea-cycle defect unmasked by the Atkins diet. Measurements of serum ammonia level must be part of the basic work-up in all patients presenting with encephalopathy of unknown origin even in the absence of liver dysfunction. Awareness of this important association can contribute to prompt diagnosis and life-saving treatment. Correct diagnosis is also important to prevent future recurrences and to provide genetic counselling for family members.
Journal of Hepatology 02/2010; 52(2):292-5. · 9.86 Impact Factor
[show abstract][hide abstract] ABSTRACT: Mitochondrial calcium overload triggers apoptosis and also regulates ATP production. ATP and uridine-5'-triphosphate (UTP) depletion from hepatic tissue after ischemia causes cell death. ATP and UTP binds to cell membranes of the hepatocytes through P2Y receptors. Our aim was to investigate the role of UTP on the hepatic injury induced by ischemia.
Isolated mouse livers were randomly divided into five groups: (1) control group; (2) ischemic group (90 min); (3) as group 2, but with the administration of UTP; (4) as group 2, but with the administration of suramin, a P2Y antagonist; and (5) as group 3, but with the simultaneous administration of suramin and UTP.
There was a postischemic significant reduction in the release of liver enzymes in the animals pretreated with UTP, the intrahepatic caspase-3 activity was significantly decreased, and the intrahepatic ATP content increased compared with group 2 (ischemic untreated). UTP prevented intracellular Ca overload after hypoxia in hepatocyte cultures. In the UTP-treated groups, significantly fewer apoptotic hepatocyte cells were noted by weaker activation of caspase-3 and by the transferase-mediated dUTP nick end labeling assay. The administration of suramin prevented the beneficial effect of endogenous ATP. UTP treatment attenuated the degradation of IkappaBalpha (nuclear factor-kappaB inhibitor) by 80% during reperfusion with no effect on c-Jun N terminal kinase phosphorylation.
The administration of UTP before induction of ischemia-reperfusion can attenuate hepatic injury. UTP administration decreased cytosolic Ca overload in hypoxic conditions. UTP-mediated protective effects may be regulated through nuclear factor- kappaB inactivation. These findings have important implications for the potential use of UTP in ischemic hepatic injury.
[show abstract][hide abstract] ABSTRACT: Liver transplantation is considered the treatment of choice for most children with deteriorating fulminant hepatic failure (FHF). Living-related donor liver transplantation (LDLT) has been suggested as an alternative to cadaveric liver transplantation to overcome the shortage of organ donors. However, experience with LDLT for children with FHF is limited in the Western world.
To present the experience with LDLT for children with FHF in a major referral center in Israel.
The files of all children who underwent primary LDLT for FHF were reviewed for demographic, clinical, and laboratory parameters before and after transplantation.
: During 1996 to 2007, 13 children diagnosed with FHF underwent primary LDLT. Median age was 4 years (range 0.75-14 years); the causes of FHF were acute hepatitis A in 4 patients and were unknown in 9 patients. Short-term complications, documented in 12 children, included mainly hepatic artery thrombosis (n = 5), which warranted retransplantation in 3 cases, and biliary leaks (n = 3). Three patients died within the first month after LDLT of severe intraoperative bleeding (n = 1), severe brain edema (n = 1), and multiorgan failure (n = 1). Long-term complications were less common and included mainly ascending cholangitis (n = 3). Patient survival rate was 68% at 1 year and 57% at 5 years. None of the donors had long-term complications.
Among children with FHF, LDLT can serve as a timely and lifesaving alternative to cadaveric donation, and could reduce the dependence on cadaveric livers in this setting.
Journal of pediatric gastroenterology and nutrition 05/2009; 48(4):451-5. · 2.18 Impact Factor
[show abstract][hide abstract] ABSTRACT: The hepatic histology in nonalcoholic fatty liver disease can vary from isolated hepatic steatosis to steatohepatitis can progress to cirrhosis and liver-related death. The aim was to evaluate the use of blood serum N-glycan fingerprinting as a tool for differential diagnosis of nonalcoholic steatohepatitis from steatosis. A group of 47 patients with NAFLD was diagnosed by clinical laboratory analysis and ultrasonography, and was studied histologically using the Brunt's scoring system. The control group included 13 healthy individuals. N-glycan profiles of serum proteins were determined by DNA sequencer-based carbohydrate analytical profiling. We have found that the concentrations of two glycans (NGA2F and NA2) and their logarithm ratio of NGA2F versus NA2 (named GlycoNashTest) were associated with the degree of NASH-related fibrosis, but had no correlation with the grade of inflammation nor steatosis severity. When used to screen NAFLD patients, GlycoNashTest could identify advanced NASH-related fibrosis (F3-F4) with the diagnosis sensitivity of 89.5% and specificity of 71.4%. The serum N-glycan profile is a promising noninvasive method for detecting NASH or NASH-related fibrosis in NAFLD patients, which could be a valuable supplement to other markers currently used in diagnosis of NASH.
Journal of Proteome Research 02/2009; 8(2):463-70. · 5.06 Impact Factor
[show abstract][hide abstract] ABSTRACT: Hyperammonemia with or without ascites with normal synthetic liver functions after liver transplantation might indicate the presence of anastomotic stenosis of the portal or hepatic vein or the existence of a patent portosystemic shunt. The authors describe six patients, three children after split-liver transplantation and three adults after cadaver liver transplantation, who presented with hyperammonemia. Three patients had ascites. All lesions were successfully treated percutaneously; stents were placed in patients with anastomotic stenoses and coil embolization was performed in patients with patent portosystemic shunts--with either transhepatic or transjugular approaches according to the site of the abnormality. Ammonia levels returned to normal, and ascites had regressed completely for at least 3 months.
Journal of vascular and interventional radiology: JVIR 01/2009; 20(2):259-63. · 1.81 Impact Factor
[show abstract][hide abstract] ABSTRACT: The C-caffeine breath test (CBT) is a noninvasive tool for the evaluation of the cytochrome P450 system, implicated in the development of nonalcoholic steatohepatitis.
To apply the CBT to assess the extent of hepatic fibrosis in patients with nonalcoholic fatty liver disease (NAFLD).
Twenty-six consecutive patients (mean age 56.1+/-6.85 y, 69.2% women) with NAFLD underwent the CBT, in addition to the clinical and laboratory evaluations and liver biopsy. Ten healthy individuals matched for age served as controls.
Mean delta over baseline values differed significantly between patients and controls (1.51+/-0.9 vs. 2.37+/-0.8 Delta per thousand/mg, respectively) (P=0.01) and were significantly higher in patients with fibrosis stage <2 (Brunt's system) (2.0+/-0.77 vs. 1.3+/-0.9 for stage > or =2, P=0.05). Mean delta over baseline values correlated highly with fibrosis stage (P=0.01), albumin (P=0.007), international normalized ratio (P=0.04), bilirubin (P=0.0008), and platelet count (P=0.0001). On multivariate stepwise logistic regression analysis, CBT was the best predictor of severe fibrosis (stage > or =2) (odds ratio 0.274, 95% confidence interval 0.086-0.872, P=0.028), with an area under the curve of 0.788.
The CBT is safe and easy to perform. It can reliably predict severe hepatic fibrosis in patients with NAFLD. Further large-scale studies are still needed.
Journal of Clinical Gastroenterology 04/2008; 42(4):408-12. · 3.20 Impact Factor
[show abstract][hide abstract] ABSTRACT: Apoptosis is a central mechanism of cell death following reperfusion of the ischemic liver. Recombinant human erythropoietin (rhEPO) have an important role in the treatment of myocardial ischemia/reperfusion (I/R) injury, by preventing apoptosis. The aim of the study was to investigate the effect of different regimens of rhEPO in preventing apoptosis following I/R-induced hepatic injury.
Isolated mouse livers were randomly divided into five groups: (1) control group, perfused for the whole study period (105 min); (2) 30-min perfusion followed by 90 min of ischemia and 15 min of reperfusion; (3), (4) and (5) like group 2, but with administration of rhEPO 5,000 units/kg i.p. at 30 min, 24 h, or both 30 min and 24 h respectively, before induction of ischemia. Perfusate liver enzyme levels and intrahepatic caspase-3 activity were measured, and apoptotic cells were identified by morphological criteria, TUNEL assay, and immunohistochemistry for caspase-3. Using immunoblot the expression of the proapoptotic JNK and inhibitor of NFkappaB (IkappaBalpha) were also evaluated. von Willebrand factor (vWF) immunohistochemistry was used as a marker of endothelial cells.
Compared to the I/R livers, all 3 rhEPO pretreated groups showed: a significant reduction in liver enzyme levels (P < 0.05) and intrahepatic caspase-3 activity (P < 0.05), fewer apoptotic hepatocytes (P < 0.05) and positive vWF staining in numerous endothelial cells lining the sinusoids. EPO decreased JNK phosphorylation and the degradation of the inhibitor of NFkappaB (IkappaBalpha) during I/R. There was no added benefit of the multiple- over the single-dose rhEPO regimen.
Pretreatment with one dose of rhEPO can attenuate post-I/R hepatocyte apoptotic liver damage. NFkappaB and JNK activation is likely to play a pivotal role in the pathophysiology of I/R hepatic injury and might have a key role in EPO-mediated protective effects. This effect is associated with the increase in sinusoidal vWF immunostaining suggests an additional effect of rhEPO in liver angiogenesis recovery. These findings have important implications for the potential use of rhEPO in I/R injury during liver transplantation.
[show abstract][hide abstract] ABSTRACT: The hepatitis C virus (HCV) F protein is a recently described, frameshift product of HCV core encoding sequence with unknown biological function. In this study we sought to characterize the prevalence of specific anti-F antibodies in patients with chronic HCV infection and to analyze the anti-F antibody profile before, during, and after antiviral treatment in order to gain a better understanding of the role of F protein in HCV pathogenesis. Serum samples were collected from 44 patients with chronic HCV infection and from 19 healthy controls. Consecutive samples from 27 patients taken before, during, and after treatment with antiviral therapy. The F and the core proteins were cloned from the HCV genome. The recombinant proteins were expressed in Escherichia coli and affinity purified. A sensitive and specific enzyme-linked immunosorbent assay was developed to assess the prevalence of anti-F antibodies. Eighty-nine percent of chronic HCV patients had evidence of anti-F antibodies, and 95% of them had anti-core antibodies. No correlation of anti-F antibodies was found with response to treatment, genotype, or seroconversion. We conclude that the F protein elicits specific antibodies in most individuals chronically infected with HCV with no correlation with response to treatment. Our results confirm the expression of F protein during natural HCV infection.
Digestive Diseases and Sciences 10/2007; 52(9):2427-32. · 2.26 Impact Factor
[show abstract][hide abstract] ABSTRACT: Apoptosis appears to be a central mechanism of cell death following reperfusion of the ischemic liver. The aim of this study was to determine the effect of decreased expression of the proapoptotic Bax gene on hepatic apoptotic warm ischemia/reperfusion (I/R) injury. Three groups of mice were studied: homozygotic knockout mice (Bax-/-); heterozygotic (Bax+/-); and wild type (Bax+/+). Isolated mouse livers were subjected to 90 minutes of ischemia (37 degrees C) followed by 15 minutes of reperfusion. Bax and Bcl-2 expression in liver tissue homogenates was measured by Western blot. Serum liver enzyme levels were measured and intrahepatic caspase-3 activity was determined by fluorimetric assay. Oil red O (ORO) staining was performed for fat detection. Apoptotic cells were identified by morphological criteria, immunohistochemistry for caspase-3, and terminal deoxynucleotidyl transferase-mediated 2'-deoxyuridine 5'-triphosphate nick-end labeling (TUNEL) assay. At 1 minute of reperfusion, the ischemic (Bax-/-) livers were characterized by statistically significantly lower liver enzyme levels and lower caspase-3 activity than the ischemic (Bax+/+) livers (P<0.05 for both). The reduction in postischemic apoptotic hepatic injury in the ischemic Bax-/- livers group was confirmed morphologically, by the significantly reduced microvesicular steatosis as determined by ORO staining, fewer apoptotic hepatocyte cells detected (P<0.05); immunohistochemically, by the significantly weaker activation of caspase-3 compared to the ischemic group (P<0.05); and by TUNEL assay (P<0.05). Similar levels of antiapoptotic Bcl-2 protein expression were detected in all 3 groups of ischemic livers on Western blots. Bax protein was not expressed in Bax-deficient livers and was detected in Bax+/+ normal livers. In the Bax+/- livers, levels of the damage markers were moderate. In conclusion, The better tolerance of Bax knockout livers to I/R injury suggests that the Bax gene may serve as a potential target for therapeutic intervention in hepatic I/R injury.
[show abstract][hide abstract] ABSTRACT: Cytokines and chemokines are proteins that play a critical role in the regulation of immunity and inflammation in patients with chronic Hepatitis C. The aim of our study was to correlate serum cytokines, chemokines and apoptosis in non-treated chronic hepatitis C patients with various degrees of inflammation and fibrosis. We studied 778 patients: 59 had low Knodell fibrosis score and low Knodell histological activity index; 372 had mild fibrosis and low histological activity index; 270 had moderate fibrosis and moderate histological activity index; and, 77 had high fibrosis and high histological activity index on their biopsy. Serum cytokines, chemokines and apoptosis were measured by enzyme-linked-immunosorbent-assay. Multivariate analysis was employed for statistical purposes. A positive correlation was seen between the degree of inflammation and tumor necrosis factor-alpha (TNF-alpha) levels (r = 0.92) in non-cirrhotic patients and between interleukin 2 in all patients (r = 0.85). Interleukin-8 increased significantly at higher histological activity indices and continued to increase in patients with cirrhosis. Transforming growth factor-beta (TGF-beta) levels increased significantly with the severity of fibrosis, but decreased in cirrhotics. In conclusion, cytokines, chemokines and apoptosis levels reflect the progression of inflammation and fibrosis in hepatitis C infected patients, but their signatures differ.
Translational Research 04/2007; 149(3):126-36. · 3.49 Impact Factor
[show abstract][hide abstract] ABSTRACT: The progression of HCV-related disease is particularly aggressive in the post-transplantation setting. Recipients with recurrent HCV infection undergo repeated liver biopsies in order to estimate disease progression. A strong association was found between serum immunoglobulins levels and hepatic fibrosis in non-transplanted patients with chronic HCV infection. The aim of this study was to determine if serum globulin and immunoglobulins levels can predict the extent of fibrosis in patients with recurrent HCV infection. The records of 45 patients (mean age 51.6 +/- 10.5 yr; 53.3% men) with biochemical, serologic, virologic, and histological evidence of recurrent HCV infection were reviewed. Recurrence developed after a median interval of 11.7 months (range: 3-106); in 14 patients (31.1%), the recurrent infection was severe. The mean duration of follow-up was 51.4 +/- 35.4 months. A total of 96 liver biopsies were performed. The mean fibrosis score increased significantly with an increase in the number of biopsies (p < 0.0001, r = 0.44). On multivariate analysis, the only predictors of severe fibrosis were serum levels of globulin (OR: 5.97, 95% CI: 1.82-19.53; p = 0.0004) and IgG (OR: 1.003, 95% CI: 1.001-1.006; p = 0.018). On linear regression analysis, for each 0.5-g/dL increase in serum globulin level, there was a 0.22-point increase in fibrosis stage. In conclusion, serum levels of globulin and IgG can serve as a noninvasive marker of the extent of hepatic fibrosis in patients with post-transplant recurrent HCV infection, thus avoiding the need for repeated liver biopsies. These findings, if confirmed, have important implications for the prevention and treatment of fibrosis in this patient group.