Zamira Hernandez-Nazara

Association of the ε2 Allele of Apoe Gene to Hypertriglyceridemia and to Early‐Onset Alcoholic Cirrhosis

BACKGROUND The diverse incidence of alcoholic cirrhosis around the world and the fact that not all alcoholic drinkers develop liver disease indicates that genetic and environmental factors play an important role in the development of liver cirrhosis. Lipids participate in early stages of alcoholic cirrhosis. Therefore variations in the plasma lipid profile due to primary (genetic) or secondary (environmental) dyslipidemia could affect the development of liver disease. The aim of this study was to analyze the lipid profile and apolipoprotein E (APOE) polymorphism in patients with alcoholic liver cirrhosis (AC) and determine the risk associated with genotype polymorphism with the onset of alcoholic cirrhosis. METHODS In a case and control study, 86 patients with AC divided into hyperlipidemic (H) and non-hyperlipidemic (non-H) groups, and 133 healthy individuals (C) matched by age and sex were studied. Lipid profile and liver function tests were measured by enzymatic methods. The APOE genotypes were identified by PCR-RFLPs. RESULTS A statistically significant increase of the APOE*2 allele and genotypes 2/2, 2/3, and 2/4 was present in AC patients compared to C group. A hyperlipidemic state characterized by increased levels of triglycerides and apolipoprotein B (APOB) and a decrease of high density lipoprotein-cholesterol (HDL-c) was detected in young-aged patients (31.2 +/- 6.2 years old vs. 46.3 +/- 12.5 years old). In this group, hypertriglyceridemia was closely associated to APOE*2 allele and to an early onset of liver cirrhosis. By contrast, APOE*4 allele was associated with a longer duration of alcohol intake (>20 years) in the non-H group. CONCLUSIONS This study shows the association of hypertriglyceridemia and APOE allele with the early onset of alcoholic liver cirrhosis, and the interaction between environmental factors, such as duration of alcohol abuse and amount of alcohol intake, and genetic factors (APOE*2 allele) on the hypertriglyceridemic process.

Effect of Ala54Thr polymorphism of FABP2 on anthropometric and biochemical variables in response to a moderate-fat diet

OBJECTIVE To analyze the effect of the fatty acid-binding protein (FABP2) gene Ala54Thr polymorphism on anthropometric and biochemical variables in response to a moderate-fat diet in overweight or obese subjects. METHODS One hundred nine subjects with a body mass index ≥ 25 kg/m(2) were studied. Participants underwent a dietary intervention that consisted of 30% fat (saturated fat <7% of total calories), 15% protein, and 55% carbohydrates. The FABP2 genotypes were analyzed by polymerase chain reaction-restriction fragment length polymorphism. Anthropometric and biochemical data were measured at baseline, 1 mo, and 2 mo of nutritional intervention. RESULTS The mean age was 38.6 ± 11.3 y and the mean body mass index 32.7 ± 6.1 kg/m(2), with 20 men (18%) and 89 women (82%). Fifty-three patients (48.6%) had genotype Ala54Ala (wild-type group) and 56 patients had genotype Ala54Thr/Thr54Thr (51.4%, mutant group). At baseline, no significant difference was found between the FABP2 genotypes groups, except for the carbohydrate intake and resting metabolic rate, which were higher in the Ala54Thr/Thr54Thr group (P < 0.05). At 2 mo, participants had lost 6.8% of their initial weight. The Ala54Thr/Thr54Thr group compared with the Ala54Ala group showed significant decreases in the parameters of weight (-7.5 versus -4.2 kg), body mass index (-2.1 versus -1.2 kg/m(2)), waist circumference (-7.6 versus -5.2 cm), waist-to-hip ratio (-0.04 versus -0.02), and C-reactive protein (-1.4 versus -0.76 mg/L), respectively (P < 0.05). After the resting metabolic rate was adjusted, the decreases in waist circumference, waist-to-hip ratio, and C-reactive protein remained significant between the two groups. CONCLUSIONS This study showed that the Thr54 allele carriers responded better to a moderate-fat diet.

Multiple cytokine expression profiles reveal immune-based differences in occult hepatitis B genotype H-infected Mexican Nahua patients

A high prevalence of occult hepatitis B (OHB) genotype H infections has been observed in the native Mexican Nahua population. In addition, a low incidence of hepatitis B virus (HBV)-associated hepatocellular carcinoma has been described in Mexico. The immune response to infection among OHB-infected patients has been poorly evaluated in vivo. Therefore, we assessed the expression profiles of 23 cytokines in OHB genotype H-infected Nahua patients. A total of 41 sera samples from natives of the Nahua community were retrospectively analysed. Based on their HBV antibody profiles, patients were stratified into two groups: OHB patients (n = 21) and patients that had recovered from HBV infection (n = 20). Herein, we report distinctive cytokines profiles in OHB-infected individuals. Compared to healthy controls (n = 20) and patients who resolved HBV infection, OHB-infected patients displayed an increase in interleukin (IL)-2 secretion in addition to a characteristic inflammation profile (decrease in IL-8 and tumour necrosis factor-alpha levels and increased levels of tumour growth factor-beta). IL-15 and interferon-gamma levels were reduced in OHB-infected individuals when compared to those patients who resolved HBV infection. In contrast, OHB patients showed an increase in monocyte chemoattractant protein (MCP)-1 and MCP-2 compared to healthy controls and patients who resolved HBV infection. These findings suggest that cytokine expression can influence the severity of OHB disease and could lead to new investigation into the treatment of liver and other infectious diseases.

Fibrogenic actions of acetaldehyde are β-catenin dependent but Wingless independent: a critical role of nucleoredoxin and reactive oxygen species in human hepatic stellate cells.

We investigated whether the fibrogenic actions of acetaldehyde, the immediate oxidation product of ethanol, are mediated via Wingless (WNT) and/or β-catenin pathways in human hepatic stellate cells (HSC). First, we show that both β-catenin small inhibitory RNA and a dominant negative-MYC expression vector markedly down-regulated the expressions of fibrogenic genes in freshly isolated HSC. We further show that acetaldehyde up-regulated platelet-derived growth factor receptor beta mRNA and protein expressions ranging from 4.0- to 7.2-fold (P<0.001). Acetaldehyde induced MYC and collagen type-1 alpha-2 mRNA and protein expressions were WNT independent because DKK1, an antagonist of the canonical WNT/β-catenin pathway, completely failed to block these inductions. Acetaldehyde increased phospho-glycogen synthase kinase-3 beta (GSK3B) protein by 31% (P<0.01), whereas phospho-β-catenin protein decreased by 50% (P ≤ 0.01). Significantly, in contrast to 43% (P<0.01) inhibition of β-catenin nuclear translocation in nucleoredoxin (NXN)-overexpressed HSC, acetaldehyde profoundly stimulated β-catenin nuclear translocation by 51%, (P<0.01). Acetaldehyde also increased the cellular reactive oxygen species level 2-fold (P<0.001) with a concomitant 2-fold (P<0.001) increase in 4-hydroxynonenal adducts. Conversely, there was a 44% decrease (P<0.001) in glutathione levels with a concomitant 76% (P<0.001) decrease in the level of NXN/ disheveled (DVL) complex. Based on these findings, we conclude that actions of acetaldehyde are mediated by a mechanism that inactivates NXN by releasing DVL, leading to the inactivation of GSK3B, and thereby blocks β-catenin phosphorylation and degradation. Thus, the stabilized β-catenin translocates to the nucleus where it up-regulates the fibrogenic pathway genes. This novel mechanism of action of acetaldehyde has the potential for therapeutic interventions in liver fibrosis induced by alcohol.

The role of dystroglycan in PDGF-BB-dependent migration of activated hepatic stellate cells/myofibroblasts

Hepatic stellate cells are embedded in the loose connective tissue matrix within the space of Disse. This extracellular matrix contains several basement membrane components including laminin, but its composition changes during liver injury because of the production of extracellular matrix components found in scar tissue. These changes in extracellular matrix composition and in cell-extracellular matrix interactions may play a key role in hepatic stellate cell transdifferentiation. In this communication we used early passages of mouse hepatic stellate cells (activated HSC/myofibroblasts) to study the platelet-derived growth factor BB (PDGF-BB)-dependent expression and regulation of β-dystroglycan and its role in activated HSC/myofibroblast migration. We used Northern and Western analysis to study dystroglycan expression and confocal microscopy to investigate changes in subcellular distribution of the protein. Activated HSC migration was investigated using an in vitro wound-healing assay. PDGF-BB induced significant changes in dystroglycan regulation and subcellular distribution of the protein. Whereas steady-state levels of dystroglycan mRNA remained constant, PDGF-BB increased dystroglycan transcription but shortened the t(1/2) by 50%. Moreover, PDGF-BB changed dystroglycan and α5-integrin cellular distribution. Cell migration experiments revealed that PDGF-BB-dependent migration of activated HSC/myofibroblasts was completely blocked by neutralizing antibodies to fibronectin, α5-integrin, laminin, and β-dystroglycan. Overall, these findings suggest that both laminin and fibronectin and their receptors play a key role in PDGF-BB-induced activated HSC migration.

Apolipoprotein AI and apolipoprotein E mRNA expression in peripheral white blood cells from patients with orthotopic liver transplantation

Background: Apolipoprotein AI/apolipoprotein E (apo‐AI/apo‐E) ratio change and its induction in non‐hepatic tissues have been reported during liver development, regeneration, and several pathophysiologic states. The clinical implication of such changes is unclear, but these could reflect recovery and/or severity of liver damage.

Asociación de los polimorfismos −319 C /T y 49 A/G del gen CTLA-4 en pacientes con infección por el virus de la hepatitis C

INTRODUCTION AND OBJECTIVE Molecular changes in the CTLA-4 gene can modify the ability to control T lymphocyte proliferation, and promote the persistence or elimination of the hepatitis C virus (HCV). We aimed to investigate the frequency and association of -319 C/T and +49 A/G polymorphism in the CTLA-4 gene in patients infected with HCV. METHODS The CTLA-4 gene polymorphisms (-319 C/T in the promoter region, and +49 A/G in exon 1) were analysed by T-ARMS-PCR in 420 individuals, including 205 chronic HCV infected patients and 215 healthy subjects. RESULTS We found a positive association of +49G allele with HCV infection (OR 1.48; 95% CI 1.09-2.02; p=.02), and with males (OR 1.80; 95% CI 1.16-2.79; p=.02), both in chronic disease (without cirrhosis). Also, significant differences in +49 A/G genotypes distribution between HCV infected patients and healthy subjects were shown in a dominant genetic model (GG+GA versus AA; OR 1.57; 95% CI 1.05-2.33; p=.04). No significant differences were observed in the -319 C/T polymorphism between HCV infected patients and healthy subjects. Moreover, -319C/+49G haplotype confers susceptibility to HCV genotype 3 infection (OR 10.68; 95% CI 1.17-96.97; p=.04). CONCLUSIONS The +49G allele confers susceptibility to HCV infection and with male gender, both in chronic disease. In addition, the -319C/+49G haplotype confers susceptibility to HCV genotype 3 infection. Our results support an important role of the -319 C/T and +49 A/G polymorphisms in HCV infection.