Rosaria Maria Pipitone

Transmembrane 6 superfamily member 2 gene variant disentangles nonalcoholic steatohepatitis from cardiovascular disease

Excess hepatic storage of triglycerides is considered a benign condition, but nonalcoholic steatohepatitis (NASH) may progress to fibrosis and promote atherosclerosis. Carriers of the TM6SF2 E167K variant have fatty liver as a result of reduced secretion of very‐low‐density lipoproteins (VLDLs). As a result, they have lower circulating lipids and reduced risk of myocardial infarction. In this study, we aimed to assess whether TM6SF2 E167K affects liver damage and cardiovascular outcomes in subjects at risk of NASH. Liver damage was evaluated in 1,201 patients who underwent liver biopsy for suspected NASH; 427 were evaluated for carotid atherosclerosis. Cardiovascular outcomes were assessed in 1,819 controls from the Swedish Obese Subjects (SOS) cohort. Presence of the inherited TM6SF2 E167K variant was determined by TaqMan assays. In the liver biopsy cohort, 188 subjects (13%) were carriers of the E167K variant. They had lower serum lipid levels than noncarriers (P < 0.05), had more‐severe steatosis, necroinflammation, ballooning, and fibrosis (P < 0.05), and were more likely to have NASH (odds ratio [OR]: 1.84; 95% confidence interval [CI]: 1.23‐2.79) and advanced fibrosis (OR, 2.08; 95% CI: 1.20‐3.55), after adjustment for age, sex, body mass index, fasting hyperglycemia, and the I148M PNPLA3 risk variant. However, E167K carriers had lower risk of developing carotid plaques (OR, 0.49; 95% CI: 0.25‐0.94). In the SOS cohort, E167K carriers had higher alanine aminotransferase ALT and lower lipid levels (P < 0.05), as well as a lower incidence of cardiovascular events (hazard ratio: 0.61; 95% CI: 0.39‐0.95). Conclusions: Carriers of the TM6SF2 E167K variant are more susceptible to progressive NASH, but are protected against cardiovascular disease. Our findings suggest that reduced ability to export VLDLs is deleterious for the liver. (Hepatology 2015;61:506‐514)

Statin use and non-alcoholic steatohepatitis in at risk individuals

BACKGROUND & AIMS Excess hepatic free cholesterol contributes to the pathogenesis of non-alcoholic steatohepatitis, and statins reduce cholesterol synthesis. Aim of this study was to assess whether statin use is associated with histological liver damage related to steatohepatitis. METHODS The relationship between statin use, genetic risk factors, and liver damage was assessed in a multi-center cohort of 1201 European individuals, who underwent liver biopsy for suspected non-alcoholic steatohepatitis. RESULTS Statin use was recorded in 107 subjects, and was associated with protection from steatosis, NASH, and fibrosis stage F2-F4, in a dose-dependent manner (adjusted p<0.05 for all). In 100 treated patients matched 1:1 for modality of recruitment, gender, presence of IFG or type 2 diabetes, PNPLA3 I148M risk alleles, TM6SF2 E167K variant, age, and BMI, statin use remained associated with protection from steatosis (OR 0.09, 95% C.I. 0.01-0.32; p=0.004), steatohepatitis (OR 0.25, 95% C.I. 0.13-0.47; p<0.001), and fibrosis stage F2-F4 (OR 0.42, 95% C.I. 0.20-0.8; p=0.017). Results were confirmed in a second analysis, where individuals were matched within recruitment center (p<0.05 for all). The protective effect of statins on steatohepatitis was stronger in subjects not carrying the I148M PNPLA3 risk variant (p=0.02 for interaction), as statins were negatively associated with steatohepatitis in patients negative (p<0.001), but not in those positive for the I148M variant (p=n.s.). CONCLUSIONS Statin use was associated with protection towards the full spectrum of liver damage in individuals at risk of non-alcoholic steatohepatitis. However, the I148M PNPLA3 risk variant limited this beneficial effect.

The MBOAT7-TMC4 Variant rs641738 Increases Risk of Nonalcoholic Fatty Liver Disease in Individuals of European Descent.

BACKGROUND & AIMS Nonalcoholic fatty liver disease (NAFLD) is a leading cause of liver damage and is characterized by steatosis. Genetic factors increase risk for progressive NAFLD. A genome-wide association study showed that the rs641738 C>T variant in the locus that contains the membrane bound O-acyltransferase domain-containing 7 gene (MBOAT7, also called LPIAT1) and transmembrane channel-like 4 gene (TMC4) increased the risk for cirrhosis in alcohol abusers. We investigated whether the MBOAT7-TMC4 is a susceptibility locus for the development and progression of NAFLD. METHODS We genotyped rs641738 in DNA collected from 3854 participants from the Dallas Heart Study (a multi-ethnic population-based probability sample of Dallas County residents) and 1149 European individuals from the Liver Biopsy Cross-Sectional Cohort. Clinical and anthropometric data were collected, and biochemical and lipidomics were measured in plasma samples from participants. A total of 2736 participants from the Dallas Heart Study also underwent proton magnetic resonance spectroscopy to measure hepatic triglyceride content. In the Liver Biopsy Cross-Sectional Cohort, a total of 1149 individuals underwent liver biopsy to diagnose liver disease and disease severity. RESULTS The genotype rs641738 at the MBOAT7-TMC4 locus associated with increased hepatic fat content in the 2 cohorts, and with more severe liver damage and increased risk of fibrosis compared with subjects without the variant. MBOAT7, but not TMC4, was found to be highly expressed in the liver. The MBOAT7 rs641738 T allele was associated with lower protein expression in the liver and changes in plasma phosphatidylinositol species consistent with decreased MBOAT7 function. CONCLUSIONS We provide evidence for an association between the MBOAT7 rs641738 variant and the development and severity of NAFLD in individuals of European descent. This association seems to be mediated by changes in the hepatic phosphatidylinositol acyl-chain remodeling.

IL28B and PNPLA3 polymorphisms affect histological liver damage in patients with non-alcoholic fatty liver disease

BACKGROUND & AIMS Genetic background may affect liver damage in patients with non-alcoholic fatty liver disease (NAFLD). The main outcomes of the study were to assess whether IL28B rs12979860 and rs8099917 polymorphisms, together with PNPLA3 rs738409 C>G polymorphism, are associated with lobular inflammation and fibrosis, in NAFLD patients. METHODS One hundred sixty consecutive NAFLD patients were assessed by liver biopsy (Kleiner score); anthropometric, and biochemical and metabolic features were included. IL28B rs12979860 C>T, IL28B rs8099917 G>C, and PNPLA3 rs738409 C>G single nucleotide polymorphisms were tested. RESULTS Seventy-four (46.2%) patients had IL28B rs12979860 CC polymorphism, compared with 72 (45%) and 14 (8.8%) with TC and TT variants, respectively. PNPLA3 rs738409 CC polymorphism was present in 47 (29.4%) patients, compared with 79 (49.4%) and 34 (21.3%) with CG and GG variants, respectively. Multivariate logistic regression analysis showed that age (OR 1.043, 95% CI 1.012-1.075, p=0.007), triglycerides (OR 1.005, 95% CI 1.000-1.010, p=0.04), hyperuricemia (OR 5.027, 95% CI 1.839-13.742, p=0.002), IL28B rs12979860 TT/TC (OR 0.219, 95% CI 0.101-0.472, p<0.001), and steatosis grade (OR 1.704, 95% CI 1.048-2.773, p=0.03) were independently linked to moderate-severe lobular inflammation. Finally, IL28B rs12979860 CC was associated with severe fibrosis (F3-F4) on univariate analysis, even if only older age (OR 1.064, 95% CI 1.026-1.104, p=0.001), high HOMA (OR 1.213, 95% CI 1.068-1.377, p=0.003), and lobular inflammation (OR 3.181, 95% CI 1.438-7.036, p=0.004), remained associated in multivariate logistic regression analysis. CONCLUSIONS In NAFLD patients, IL28B rs12979860 CC genotype, together with PNPLA3 rs738409 GG, is associated with the severity of liver damage.

Identification of Biphenyl-Based Hybrid Molecules Able To Decrease the Intracellular Level of Bcl-2 Protein in Bcl-2 Overexpressing Leukemia Cells

With the aim of enhancing the structural complexity and diversity of an existing collection of bi- and terphenyl compounds, we synthesized hybrid molecules comprising of spirocyclic ketones (a complexity-bearing core) and bi/terphenyls (privileged fragments). Compounds 1, 3, 4, and 6 showed well-defined activity on apoptosis and differentiation, making them potential leads for development as new anticancer agents and chemical probes to study signaling networks in neoplastic cells.

Glucokinase Regulatory Protein Gene Polymorphism Affects Liver Fibrosis in Non-Alcoholic Fatty Liver Disease

Background and Aims Variant in glucokinase regulatory protein (GCKR), associated with lipid and glucose traits, has been suggested to affect fatty liver infiltration. We aimed to assess whether GCKR rs780094 C→T SNP influences the expression of steatosis, lobular inflammation and fibrosis in NAFLD patients, after correction for PNPLA3 genotype. Methods In 366 consecutive NAFLD patients (197 from Sicily, and 169 from center/northern Italy), we assessed anthropometric, biochemical and metabolic features; liver biopsy was scored according to Kleiner. PNPLA3 rs738409 C>G and GCKR rs780094 C>T single nucleotide polymorphisms were also assessed. Results At multivariate logistic regression analysis in the entire NAFLD cohort, the presence of significant liver fibrosis (>F1) was independently linked to high HOMA (OR 1.12, 95% CI 1.01–1.23, p = 0.02), NAFLD activity score ≥5 (OR 4.09, 95% CI 2.45–6.81, p<0.001), and GCKR C>T SNP (OR 2.06, 95% CI 1.43–2.98, p<0.001). Similar results were observed considering separately the two different NAFLD cohorts. GCKR C>T SNP was also associated with higher serum triglycerides (ANOVA, p = 0.02) in the entire cohort. Conclusions In patients with NAFLD, GCKR rs780094 C>T is associated with the severity of liver fibrosis and with higher serum triglyceride levels.

PNPLA3 GG Genotype and Carotid Atherosclerosis in Patients with Non-Alcoholic Fatty Liver Disease

Background and Aim To evaluate if the presence of carotid atherosclerosis in patients with NAFLD, could be related to gene variants influencing hepatic fat accumulation and the severity of liver damage. Methods We recorded anthropometric, metabolic and histological data(Kleiner score) of 162 consecutive, biopsy-proven Sicilian NAFLD patients. Intima-media thickness(IMT), IMT thickening(IMT≥1 mm) and carotid plaques(focal thickening of >1.3 mm at the level of common carotid artery) were evaluated using ultrasonography. IL28B rs12979860 C>T, PNPLA3 rs738409 C>G, GCKR rs780094 C>T, LYPLAL1 rs12137855 C>T, and NCAN rs2228603 C>T single nucleotide polymorphisms were also assessed. The results were validated in a cohort of 267 subjects with clinical or histological diagnosis of NAFLD from Northern Italy, 63 of whom had follow-up examinations. Results Carotid plaques, IMT thickening and mean maximum IMT were similar in the two cohorts, whereas the prevalence of diabetes, obesity, NASH, and PNPLA3 GG polymorphism(21%vs.13%, p = 0.02) were significantly higher in the Sicilian cohort. In this cohort, the prevalence of carotid plaques and IMT thickening was higher in PNPLA3 GG compared to CC/CG genotype(53%vs.32%, p = 0.02; 62%vs.28%, p<0.001, respectively). These associations were confirmed at multivariate analyses (OR2.94;95%C.I. 1.12–7.71, p = 0.02, and OR4.11;95%C.I. 1.69–9.96, p = 0.002, respectively), although have been observed only in patients <50years. Also in the validation cohort, PNPLA3 GG genotype was independently associated with IMT thickening in younger patients only (OR: 6.00,95%C.I. 1.36–29, p = 0.01), and to IMT progression (p = 0.05) in patients with follow-up examinations. Conclusion PNPLA3 GG genotype is associated with higher severity of carotid atherosclerosis in younger patients with NAFLD. Mechanisms underlying this association, and its clinical relevance need further investigations.

Galangin increases the cytotoxic activity of imatinib mesylate in imatinib-sensitive and imatinib-resistant Bcr-Abl expressing leukemia cells

Resistance to imatinib mesylate is an emergent problem in the treatment of Bcr-Abl expressing myelogenous leukemias and additional therapeutic strategies are required. We observed that galangin, a non-toxic, naturally occurring flavonoid was effective as anti-proliferative, and apoptotic agent in Bcr-Abl expressing K562 and KCL22 cells and in imatinib mesylate resistant K562-R and KCL22-R cells. Galangin induced an arrest of cells in G0-G1phase of cell cycle and a decrease in pRb, cdk4, cdk1, cycline B levels; moreover, it was able to induce a monocytic differentiation of leukemic Bcr-Abl+ cells. Of note, galangin caused a decrease in Bcl-2 levels and markedly increased the apoptotic activity of imatinib both in sensitive or imatinib-resistant Bcr-Abl+ cell lines. In contrast, flavonoids unable to modify the Bcl-2 intracellular levels, such as fisetin and chrysin, did not increase the apoptotic effect of imatinib. These data suggest that galangin is an interesting candidate for a combination therapy in the treatment of imatinib-resistant leukemias.

Insulin-Like Growth Factor-I, Inflammatory Proteins, and Fibrosis in Subjects With Nonalcoholic Fatty Liver Disease

CONTEXT Inflammation may have a pathogenic role in the progression of nonalcoholic fatty liver disease (NAFLD); by contrast, the role of anti-inflammatory molecules has not been addressed. Low circulating levels of the anti-inflammatory molecule IGF-I have been described in subjects with NAFLD. OBJECTIVE The aim of the study was to elucidate the clinical significance of IGF-I in NAFLD and its relationship with inflammatory biomarkers and fibrosis. DESIGN AND SETTING We conducted a cross-sectional study and in vitro experiments on hepatic HepG2 cells at the Internal Medicine and Gastrointestinal and Liver Units of the Universities of Catanzaro and Palermo. SUBJECTS A total of 221 individuals with NAFLD diagnosed on ultrasonography (cohort 1) and 50 subjects with biopsy-proven NAFLD (cohort 2) participated in the study. INTERVENTION Liver ultrasonography was performed on cohort 1, and hepatic biopsies were obtained from cohort 2. MAIN OUTCOME MEASURES NAFLD fibrosis and Kleiner scores were calculated. IGF-I and inflammatory biomarker plasma concentrations were assessed with specific assays. In the in vitro study, real-time RT-PCR was used to assess the mRNA expression levels of acute-phase reactants. RESULTS In the first cohort, circulating IGF-I levels showed an inverse correlation with NAFLD fibrosis score and inflammatory biomarkers; similarly in the second cohort, liver IGF-I mRNA levels and the fibrosis score showed a negative relationship. Finally, we showed that IGF-I was able to directly modulate the expression of acute-phase reactants, decreasing C-reactive protein and fibrinogen levels and up-regulating albumin expression in HepG2 cells. CONCLUSIONS The present data suggest that evaluation of circulating IGF-I and proinflammatory markers might be useful to assess comprehensively the severity of the disease in individuals with NAFLD.

Association of vitamin D serum levels and its common genetic determinants, with severity of liver fibrosis in genotype 1 chronic hepatitis C patients.

Lower 25‐hydroxyvitamin D [25(OH)D] serum levels have been associated with the severity of liver fibrosis in genotype 1 chronic hepatitis C patients (G1CHC). In addition, a recent genome‐wide study identified genetic variants (rs12785878, near dehydrocholesterol reductase, DHCR7; rs10741657, near CYP2R1; and rs7041, near vitamin D‐binding protein, GC) affecting 25(OH)D serum levels in healthy populations. We aimed to assess the association between vitamin D serum levels and its genetic determinants, with the severity of liver fibrosis. Two hundred and sixty patients with biopsy‐proven G1CHC were consecutively evaluated. The 25(OH)D serum levels were measured by high‐pressure liquid chromatography. All patients were genotyped for DHCR7 rs12785878, CYP2R1 rs10741657 and GC rs7041 single nucleotide polymorphisms. DHCR7 GG genotype (P = 0.003) and the severity of fibrosis (P = 0.03) were independent factors associated with lower 25(OH)D serum levels in multiple linear regression analysis. Interestingly, 53.8% (7/13) of patients with DHCR7 GG genotype had severe liver fibrosis, compared to 27.1% (67/247) of those with DHCR7 TT/TG genotype (P = 0.03). By multivariate logistic regression analysis, severe fibrosis was independently associated with older age (OR, 1.056; 95% CI, 1.023–1.089, P = 0.001), low cholesterol (OR, 0.984; 95% CI, 0.974–0.994, P = 0.002), high triglycerides (OR, 1.008; 95% CI, 1.002–1.015, P = 0.01), low 25(OH)D (OR, 0.958; 95% CI, 0.919–0.999, P = 0.04), DHCR7 GG genotype (OR, 4.222; 95% CI, 1.106–16.120; P = 0.03), moderate–severe steatosis (OR, 2.588; 95% CI, 1.355–4.943; P = 0.004) and moderate–severe necroinflammatory activity (grading) (OR, 2.437; 95% CI, 1.307–4.763; P = 0.001). No associations were found between liver fibrosis and both CYP2R1 and GC genotypes. In patients with G1CHC, GG homozygosis for DHCR7 gene and lower 25(OH)D levels are independently associated with the severity of liver fibrosis.