Platelet production and destruction in liver cirrhosis.

BACKGROUND & AIMS: Thrombocytopenia is common in liver cirrhosis (LC) but the mechanisms are not fully understood. The purpose of our work was to evaluate platelet kinetics in LC with different etiologies by examining platelet production and destruction. METHODS: Ninety-one consecutive LC patients (36 HCV, 49 alcoholics, 15 HBV) were enrolled. As controls, 25 subjects with idiopathic thrombocytopenic purpura, 10 subjects with aplastic anemia, and 40 healthy blood donors were studied. Plasma thrombopoietin (TPO) was measured by ELISA. Reticulated platelets (RP) were determined using the Thiazole Orange method. Plasma glycocalicin (GC) was measured using monoclonal antibodies. Platelet associated and serum antiplatelet antibodies were detected by flow cytometry. B-cell monoclonality in PBMC was assessed by immunoglobulin fingerprinting. RESULTS: Serum TPO was significantly lower in LC (29.9±18.1 pg/ml) compared to controls (82.3±47.6 pg/ml). The GC levels were higher in LC (any etiology) than in healthy cases. Conversely, the absolute levels of RP were lower in LC (any etiology) than in healthy controls. The platelet-associated and serum anti-platelet antibodies were higher in HCV+ LC compared to healthy subjects (p<0.0064), alcoholic LC (p<0.018), and HBV+ LC (p<0.0001). B-cell monoclonality was found in 27% of the HCV+LC, while it was not found in HBV+ or alcoholic LC. CONCLUSIONS: Patients with LC present decreased plasma TPO, accelerated platelet turnover, and reduced platelet production. This indicates that LC thrombocytopenia is a multifactorial condition involving both increased platelet clearance and impaired thrombopoiesis.

Serum response factor depletion affects the proliferation of the hepatocellular carcinoma cells HepG2 and JHH6.

For hepatocellular carcinoma (HCC), a leading cause of cancer death world-wide, there is no effective therapy especially for the advanced stage of the disease. Thus, we started the investigations about a novel anti HCC approach based on the depletion of the transcription factor serum response factor (SRF) in HCC cell lines; SRF choice was based on its recently proposed contribution to HCC tissue development and on its important role in cell proliferation. SRF depletion, obtained by a siRNA (siSRF797), was studied in two HCC cell lines, i.e. HepG2 and JHH6 assigned to high and low hepatocytic differentiation grade on the base of the capacity to synthesize albumin. In the HCC cell lines examined, siSRF797 reduced both the mRNA and protein levels of SRF without inducing unspecific interferon response or cytotoxicity. Moreover, SRF depletion induced the reduction of S-phase cells and a decrease in cell number and vitality. Particularly in HepG2, cell growth impairment was paralleled by the decrease of the levels of the transcription factor E2F1 together with some of its regulated genes. In HepG2 but not in JHH6, SRF depletion was associated with apoptosis. Finally, in both HepG2 and JHH6, the combined administration of siSRF797 and bortezomib, a proteasome inhibitor whose therapeutic potential for HCC is considered attractive, further reduced cell viability compared to either siSRF797 or bortezomib treatment alone. In conclusion, SRF depletion affects the expansion of the high and low differentiation grade HCC cells HepG2 and JHH6. These results can pave the way to understand the role of SRF in HCC development and possibly to identify novel anti HCC therapeutic strategies.

Role of E2F1-cyclin E1-cyclin E2 circuit in human coronary smooth muscle cell proliferation and therapeutic potential of its downregulation by siRNAs.

Aberrant coronary vascular smooth muscle cell (CSMC) proliferation is a pivotal event underlying intimal hyperplasia, a phenomenon impairing the long-term efficacy of bypass surgery and angioplasty procedures. Consequently research has become focused on efforts to identify molecules that are able to control CSMC proliferation. We investigated downregulation of CSMC growth by small interfering RNAs (siRNAs) targeted against E2F1, cyclin E1, and cyclin E2 genes, whose contribution to CSMC proliferation is only now being recognized. Chemically synthesized siRNAs were delivered by two different transfection reagents to asynchronous and synchronous growing human CSMCs cultivated either in normo- or hyperglycemic conditions. The depletion of each of the three target genes affected the expression of the other two genes, demonstrating a close regulatory control. The clearest effects associated with the inhibition of the E2F1-cyclin E1/E2 circuit were the reduction in the phosphorylation levels of the retinoblastoma protein pRB and a decrease in the amount of cyclin A2. At the phenotypic level the downmodulation of CSMC proliferation resulted in a decrease of S phase matched by an increase of G1-G0 phase cell amounts. The antiproliferative effect was cell-donor and transfectant independent, reversible, and effective in asynchronous and synchronous growing CSMCs. Importantly, it was also evident in hyperglycemia, a condition that underlies diabetes. No significant aspecific cytotoxicity was observed. Our data demonstrate the interrelation among E2F1-cyclin E1-cyclin E2 and the pivotal role this circuit exerts in CSMC proliferation. Additionally, our work validates the concept of utilizing anti-E2F1-cyclin E1-cyclin E2 siRNAs to develop a potential novel therapy to control intimal hyperplasia.

Gene-environment interactions between HLA B7/A2, EBV antibodies are associated with MRI injury in multiple sclerosis.

PURPOSE: To determine the role of gene-environmental interactions between the Class I and Class II HLA alleles and the humoral anti-Epstein-Barr Virus (EBV) responses in the development of brain injury and clinical disability in multiple sclerosis (MS) patients. METHODS: A total of 93 MS patients (62 females; 31 males) and 122 healthy controls underwent HLA typing and testing for antibodies against EBV. The MS patients underwent brain MRI and quantitative measurements of T1- and T2-lesion volumes (LVs) and brain parenchymal fraction (BPF) were obtained. There were 54 MS cases that underwent MRI and EBV-antibody assessments at the 3-year follow-up. The anti-EBV panel included measurements of the levels of anti-EBV early antigen (EA) IgG, anti-EBV nuclear antigen (EBNA) IgG and anti-EBV viral capsid antigen (VCA) IgM and anti-EBV VCA IgG. The relationships between HLA alleles, anti-EBV antibody levels, MRI and clinical parameters were assessed in regression analysis. RESULTS: The presence of HLA B7 was associated with increased T1-LV and trends indicating increased anti-EBV VCA IgG levels, higher disability (EDSS) and more destructive MRI parameters (increased T2-LV and decreased BPF). The presence of HLA A2 was associated with lower EDSS and a trend toward decreased anti-EBV VCA IgG levels; the associations with MRI variables were not significant. The HLA B7-A2 haplotype was significantly associated with higher T2-LV and T1-LV and a trend toward lower BPF was observed. CONCLUSIONS: Our data suggest that gene-environment interactions between specific HLA Class I loci and EBV exposure are associated with MRI markers of lesion injury and brain atrophy in MS patients.

Bortezomib arrests the proliferation of hepatocellular carcinoma cells HepG2 and JHH6 by differentially affecting E2F1, p21 and p27 levels.

Despite the broad anti-tumour potential of the proteasome inhibitor bortezomib, partial information is available with regard to its effects on hepatocellular carcinoma (HCC) cells. Here we studied the effects of bortezomib on two human HCC cell lines displaying a different phenotype, hepatocyte-like for HepG2 and undifferentiated for JHH6. Bortezomib induced a dose- and time-dependent increase in cell toxicity and decrease of cell viability, with JHH6 being less sensitive than HepG2. Moreover, a differential influence on major cell cycle regulatory genes was responsible for the observed decrease of S and increase of G(2)-M phase cells. In HepG2, bortezomib induced a post-transcriptional increase of cyclin E1 together with a transcriptional-mediated decrease of the transcription factor E2F1. This in turn resulted in the reduction of the hyper-phosphorylated form of pRB and in the transcriptional down-regulation of the E2F1 targets cyclin D1, cyclin A2 and CdK2 but not cyclin E1. Up-regulation of LRH1, a liver specific cyclin E1 transcription factor, accounted for the unvaried cyclin E1 mRNA levels. Additionally, bortezomib induced both transcriptional and post-translational increase of p21(waf1/cip1) and p27(kip1). In JHH6, an overall more contained variation in cell cycle mediators was observed with the reduction of E2F1, cyclin A2, LRH1 and the increase of p21(waf1/cip1) being the most evident. In conclusion, the presented data show the mechanisms regulating cell proliferation inhibition by bortezomib in two different HCC cell lines. Despite a certain phenotype-dependent effect, the potent action exerted by bortezomib makes this drug attractive for future experimentation in animal models, possibly leading to novel treatments for HCC.

Inhibitory effects of fenofibrate on apoptosis and cell proliferation in human endothelial cells in high glucose.

Fenofibrate has beneficial effects on the progression and clinical emergence of atherosclerosis in normoglycemic and in diabetic patients. Given the involvement of endothelium in these processes, we speculated that fenofibrate may influence endothelial cell apoptosis and proliferation, regulators of endothelium integrity. Fenofibrate effects on apoptosis and proliferation were studied in human umbilical vein endothelial cells under normal (5.5 mmol/l, NG) and high (22 mmol/l, HG) glucose with or without fenofibrate (50 micromol/l). Apoptosis was evaluated by annexin V, by poly(ADP-ribose) polymerase protein cleavage, and cyclooxygenase-2 (COX-2), Bax/Bcl-2, and p53 protein levels; proliferation was assessed by determining cell cycle phase distribution and the amounts of the cell cycle regulators E2F1, cyclin D1, E1, and A and the levels of the hyper-phosphorylated form of the retinoblastoma protein (ppRb). HG resulted in increased (p<0.05) apoptosis rate associated with COX-2 protein overexpression, without modification of Bax/Bcl2 ratio and p53 levels. Fenofibrate decreased apoptosis and normalized increased COX-2 expression in HG (p<0.05). Both in HG and NG, fenofibrate dramatically reduced cell proliferation (p<0.05) through a G1/G0 block mediated by the reduction in ppRb and the decrease in E2F1, cyclin E1, A, and D1 protein expression, with a mechanism that, for cyclin E1, occurred at the posttranscriptional level. In conclusion, our data show that fenofibrate reduces apoptosis caused by HG but severely interferes with endothelial cell proliferation both in NG and HG. The resulting effect may influence endothelium integrity in vivo and may impact the outcome of acute complications of atherosclerosis in diabetes.

HLA-DRB1*1501, -DQB1*0301, -DQB1*0302, -DQB1*0602, and -DQB1*0603 alleles are associated with more severe disease outcome on MRI in patients with multiple sclerosis.

The most important confirmed genetic factor of susceptibility to multiple sclerosis (MS) has been identified in the HLA class II region. The hypothesis that several genes, including HLA class II, may influence the prognosis of patients with MS has been proposed. In a recent study, using low intermediate resolution typing, we found that some HLA alleles may predict disease severity as assessed by magnetic resonance imaging (MRI) measures. The aim of this study was to examine the relationship between high-resolution typing of HLA alleles and disease severity as measured by brain MRI quantitative markers of demyelinating and destructive pathology in patients with MS. In 41 MS patients (27 relapsing-remitting, 7 secondary progressive, and 7 primary progressive), we performed high-resolution typing of alleles HLA-DRB1*04, -DQB1*03, -DRB1*15, -DQB1*06, and of haplotypes -DRB1*04-DQB1*03 and -DRB1*15-DQB1*06. These alleles and haplotypes were associated with higher susceptibility to MS in a recently published case-control study conducted in the Friuli-Venezia-Giulia region, Italy. Of 41 included patients, 13 were men and 28 were women. Mean age was 43.3 (SD 11.4) years, mean disease duration 10.3 (SD 7.8) years, and mean EDSS 2.3. DNA extraction and genomic typing were obtained with the sequence-specific primers method using primer pairs that amplified the HLA alleles. All patients underwent a 1.5-T MRI examination of the brain. Disease severity was assessed by clinical measures [Expanded Disability Status Scale (EDSS)] and MRI measures. T2- and T1-lesion volumes (LVs) and brain atrophy measures [fractions of brain parenchyma (BPF), gray matter (GMF), and white matter (WMF)] were calculated. We used general linear model analysis (GML), controlled for age, disease duration, and treatment status, to compare the MRI measures according to allele and haplotype status. The following significant results were found: HLA-DRB1*1501 positive patients had significantly lower GMF (0.493 vs 0.526, p < 0.001), lower BPF (0.784 vs 0.815, p = 0.018), and higher T1-LV (2.8 vs 0.7ml, p = 0.036); -DQB1*0301 positive patients had significantly higher T2-LV (34.1 vs 0.7 ml, p = 0.041), and showed a trend for lower BPF (0.790 vs 0.846, p = 0.064); -DQB1*0302 positive patients had significantly lower T1-LV (2.4 vs 0.9 ml, p = 0.016); and -DQB1*0602 positive patients had significantly lower GMF (0.492 vs 0.521, p = 0.007) and lower BPF (0.781 vs 0.811, p = 0.023). No differences were found in the indices of MRI disease severity according to HLA haplotype associations. Both in correlation and in regression analyses, we observed significant associations between HLA-DRB1*1501 and lower GMF and BPF and higher T1-LV, between -DQB1*0301 and higher T2-LV and disease duration, between -DQB1*0302 and lower GMF and higher T1- and T2-LV, between -DQB1*0602 and lower GMF and BPF, and between -DQB1*0603 and higher T1-LV and EDSS. High-resolution HLA genotyping analysis revealed a robust relationship between alleles HLA-DRB1*1501, -DQB1*0301, -DQB1*0302, -DQB1*0602, and -DQB1*0603, and more severe damage on inflammatory and neurodegenerative MRI measures.

MMP-9 microsatellite polymorphism and susceptibility to carotid arteries atherosclerosis.

OBJECTIVE: The aims of this study were to compare a microsatellite polymorphism (PM) of matrix metalloproteinase (MMP)-9 in patients with carotid atherosclerosis and control population, and to assess the relationship between this PM and plaque structure. METHODS AND RESULTS: One hundred fifty patients referring to vascular diagnostic centers for suspected carotid atherosclerosis (at ultrasound examination: 110 positive, 40 negative) and controls (n=110) have been genotyped for MMP-9 PM. After controlling for risk factors, allelic and genotype frequencies were significantly different among the groups, with significant prevalence of long microsatellites in patients with carotid atherosclerosis. Long microsatellites (settled as 22 to 27 repeats) were associated with carotid atherosclerosis (odds ratio [OR], 5.2; 95% confidence interval [CI], 2.9 to 9.2), compared with controls; an independent case control study on patients with coronary atherosclerosis confirmed such result. Binary logistic regression showed that hypertension, long microsatellites in MMP-9 PM and smoking habits were variables accounting for the difference between ultrasound-positive patients and controls. Long microsatellites were also associated to plaques with thin fibrous cap and echolucent core (OR, 13.1; 95% CI, 1.6 to 100). These alleles were slightly more represented in female patients (chi2 test=0.019; OR, 2.7; 95% CI, 1.2 to 6) but not associated with other risk factors. Plasma MMP-9 levels were related neither to MMP-9 PM nor to plaque type, and were related to gender and extension of atherosclerosis in carotid arteries. CONCLUSIONS: The number of repeats (> or =22 CA) in the microsatellite of MMP-9 promoter, but not MMP-9 plasma levels, is associated to carotid atherosclerosis and particularly to plaques with a thin fibrous cap.

Relationship between human leucocyte antigen class I and class II and chronic idiopathic urticaria associated with aspirin and/or NSAIDs hypersensitivity.

BACKGROUND: HLA genes play a role in the predisposition of several diseases. The aim was to analyze the prevalence of HLA class I phenotypes and HLA-DRB1* genotype in patients with CIU associated with ASA and NSAIDs hypersensitivity (AICU). METHODS: 69 patients with AICU, and 200 healthy subjects. RESULTS: Subjects with HLA-B44 and HLA-Cw5 antigens were more represented in patients with AICU than in control group. Subjects with HLA-A11, HLA-B13, HLACw4, and HLA-Cw7 antigen were more represented in control group than in patients with AICU. Multiple logistic regression demonstrated an association of HLA-Cw4 and HLA-Cw7 with a lower risk of AICU, whereas carriers of HLA-B44 phenotype had a higher risk of AICU. No differences were found between patients and controls as regards to HLA-DRB1* genotype. CONCLUSIONS: We observed an association between some HLA class-I antigens and AICU. To the best of our knowledge this is the first description of such association.

MMP-9 microsatellite polymorphism: association with the progression of intima-media thickening and constrictive remodeling of carotid atherosclerotic plaques.

Intima-media thickening (IMT) of carotid arteries and constrictive remodeling (CR) of atherosclerotic plaques are vascular pathologic characteristics that precede the onset of vascular events. SMC migration and proliferation are linked both to IMT and CR and are matrix metalloproteinase 9 (MMP-9) dependent. A genetic polymorphism (PM) of MMP-9, a CA (13-27) microsatellite in the promoter region, which accounts for differential expression of MMP-9, could be linked to progression of IMT and CR. Progression of IMT and CR of plaques in carotid arteries were studied in 55 consecutive patients with a 12-18 months follow-up. All patients were genotyped for MMP-9 PM. A positive linear relationship between the number of repeats and the progression of IMT (P=0.028) as well as of CR (P=0.018) was found. The analogous relationship was obtained when only the allele with longer microsatellite was considered. Carriers of more than 20 repeats in one allele showed faster both IMT growth (P=0.045) and stenosis progressions of plaques (P=0.019). In multivariate analysis, age, dyslipidemia, and MMP-9 PM were determinants of IMT progression, while MMP-9 PM was the only one of CR. In conclusion, the high number of CA repeats in MMP-9 promoter is positively correlated with faster IMT and CR progression.

MMP-9 microsatellite polymorphism and susceptibility to exudative form of age-related macular degeneration.

PURPOSE: To assess if a polymorphism (PM) of the microsatellite (CA(13-27)) in the promoter region of Matrix Metalloproteinase 9 (MMP-9) was associated with the exudative form of age-related macular degeneration (AMD) and to its risk factors. METHODS: In 107 patients with AMD (AMD Group) and 223 age- and gender-matched controls (Control Group) with cataract, demographic, clinical data, and MMP-9 PM have been compared. RESULTS: The comparison of allelic frequencies showed a different pattern of CA repeats between AMD and Control Group (P < 0.00005), in particular the prevalence of longer microsatellites (> or = 22 CA repeats) was higher in AMD than in Control Group (O.R. 2.49, 95% CI 1.71-3.37, P < 0.001). Analyses of genetic frequencies gave similar results. Logistic regression confirmed that 22 or more CA repeats are associated to AMD. The only association between MMP-9 PM and other risk factors for AMD was with BMI (Spearman's R = 0.298, P < 0.00005): all patients with both microsatellites > or = 22 CA repeats were overweight or obese (chi2 test P < 0.0005, compared to other genotypes). CONCLUSIONS: Longer microsatellites in the promoter of MMP-9 are associated to the exudative form of AMD and to body mass index, a well-known risk factor for the disease.

HLA genotypes and disease severity assessed by magnetic resonance imaging findings in patients with multiple sclerosis.

The objective of the study was to examine the relationship between HLA genotypes and disease severity as measured by brain MRI quantitative markers of demyelinating and destructive pathology in patients with multiple sclerosis (MS). We studied 100 patients with MS and 122 age, sex-, ethnic- and residence-matched controls. The DNA extraction and the genomic typing (A, B, DRB1 and DQB1 loci) were obtained with sequence-specific oligonucleotide method, using a commercially available reversible line blot assay (INNO-LIPA). All patients underwent a 1.5 tesla MRI examination of the brain. Disease severity was assessed by clinical (Expanded Disability Status Scale (EDSS)) and MRI (T2- and T1-lesion load (LL) and brain parenchymal fraction (BPF)) outcome measures. HLA-DQB1* 02 (OR 19.9, 95% C. I. 16.2-24.3, uncorrected (uncorr)- p<0.00001, corr-p<0.0006), -DQB1*03 (OR 16.8, 95% C. I. 13.6-20.5, uncorr-p<0.00001, corrp< 0.0006), -DRB1*15 (OR 4.6, 95% C. I. 3.7-5.6, uncorr-p= 0.0001, corr-p=0.006), and -DRB1*03 (OR 3.9, 95% C. I. 3.2-4.8, uncorr-p=0.0001, corr-p= 0.006) alleles were associated with MS. T2-, T1-LL, BPF and EDSS were not significantly different according to the carrier status of these HLA alleles. No differences were found in the ratios of disease severity/disease duration according to the HLA carrier status. Multiple regression analysis showed that a higher T2-LL was associated with the presence of DRB1*04 (uncorr-R2=0.15, p=0.006 and corr-R2=0.11, p=0.025) and B7 alleles (uncorr-R2=0.08, p=0.02 and corr-R2=0.07, p=0.018), T1-LL was associated with B7 (uncorr-R2=0.30, p<0.0001 and corr-R2=0.27, p=0.0001) and DRB1*12 (uncorr-R2=0.25, p<0.0001 and corr-R2=0.21, p=0.0002) alleles, whereas the BPF was predicted only by the presence of DRB1*12 allele (uncorr-R2=0.24, p=0.002 and corr-R2=0.20, p=0.004). The study findings suggest that some HLA alleles may predict the destructive pathological processes visible on MRI. Since the size of the sample studied is relatively small, further studies are needed to draw any firm conclusion about genotype/phenotype correlation in patients with MS.