Liver Fibrosis Biomarkers Accurately Exclude Advanced Fibrosis and Are Associated with Higher Cardiovascular Risk Scores in Patients with NAFLD or Viral Chronic Liver Disease

Liver fibrosis predicts liver-related and cardiovascular outcomes in chronic liver disease patients. We compared the diagnostic performance of various liver fibrosis biomarkers for identifying histological significant/advanced fibrosis. Additionally, the correlations of such liver fibrosis biomarkers with cardiovascular risk (CVR) scores were evaluated. 173 patients with viral hepatitis (157 HCV and 16 HBV) and 107 with a non-alcoholic fatty liver disease (NAFLD) were consecutively enrolled. Various liver fibrosis biomarkers: aspartate aminotransferase (AST) to alanine aminotransferase (ALT) ratio (ARR), AST to Platelet Ratio Index (APRI), Fibrosis-4 (FiB-4), Forns index, NAFLD fibrosis score (NFS), BARD (body mass index (BMI), AAR, Diabetes) score, and Hepamet fibrosis score (HFS), were used to identify significant/advanced fibrosis. CVR was assessed by using the SCORE, the Progetto CUORE, or the Framingham risk scoring systems. Liver fibrosis biomarkers performed better in predicting advanced rather than significant liver fibrosis in all patients, regardless of chronic liver disease aetiology. Forns index and HFS performed best in predicting advanced fibrosis in patients with viral chronic liver disease and NAFLD. Lower cut-offs of these liver fibrosis biomarkers had high negative predictive values for advanced fibrosis overall, as well as in patients with NAFLD or viral chronic liver disease. FIB-4, Forns index, NFS, and HFS were positively correlated with SCORE and Framingham risk scores. In conclusion, liver fibrosis biomarkers accurately exclude advanced fibrosis and positively correlate with CVR scores in patients with chronic liver disease.

A round trip from nonalcoholic fatty liver disease to diabetes: molecular targets to the rescue?

Evidence suggests a close relationship between nonalcoholic fatty liver disease (NAFLD) and type two diabetes (T2D). On the grounds of prevalence of disease, both conditions account for a significant financial cost for health care systems and individuals. Aim of this review article is to explore the epidemiological basis and the putative molecular mechanisms underlying the association of NAFLD with T2D. Epidemiological studies have shown that NAFLD is associated to the development of incident T2D and either reversal or improvement of NAFLD will result into decreased risk of developing incident T2D. On the other side of the coin data have shown that T2D will worsen the course of NAFLD doubling the risk of disease progression (i.e. evolution from simple steatosis to advanced fibrosis, cirrhosis, hepatocellular carcinoma, liver transplant and death). Conversely, NAFLD will contribute to metabolic decompensation of T2D. The pathogenesis of T2D in NAFLD patients may be mediated by several hepatokines impairing metabolic control. Among these, Fetuin-B, which causes glucose intolerance and is increased in patients with T2D and NAFLD with fibrosis is one of the most promising. T2D may affect the progression of NAFLD by acting at different levels of the pathogenic cascade involving gut microbiota and expanded, inflamed, dysfunctional adipose tissue. In conclusion, T2D and NAFLD are mutually, closely and bi-directionally associated. An improved understanding of molecular pathogenesis underlying this bi-directional association may allow us to be able to prevent the development of T2D by halting the progression of NAFLD.

Do Nonalcoholic Fatty Liver Disease and Fetuin-A Play Different Roles in Symptomatic Coronary Artery Disease and Peripheral Arterial Disease?

BACKGROUND AND AIMS

Nonalcoholic fatty liver disease (NAFLD) is strongly associated with both atherosclerotic cardiovascular disease (CVD) and Fetuin-A. However, the association of Fetuin-A with atherosclerosis is more controversial. We hypothesized that the pathogenic interplay of NAFLD, Fetuin-A and atherosclerosis varies based on arterial site. Accordingly, we aimed to assess NAFLD prevalence, Fetuin-A values and their relationship with symptomatic atherosclerosis occurring in different localizations: coronary artery disease (CAD) vs. peripheral arterial disease (PAD).

METHODS

One hundred and forty-nine consecutive patients with symptomatic atherosclerotic CVD were recruited: 45 with CAD diagnosed by coronary angiography and 104 with PAD detected by doppler-ultrasound and/or computed tomography angiography and/or angiography. NAFLD was diagnosed based on both ultrasonography and exclusion of competing etiologies. Serum Fetuin-A was measured with ELISA.

RESULTS

NAFLD was detected in 54% of the overall group, with higher rates in PAD (59%) than CAD (42%) patients. Median Fetuin-A values were 256 (111-662) μg/mL, higher in patients with CAD (378 (124-662) μg/mL) than those with PAD (236 (111-461) μg/mL). The main findings were: (1) CAD patients had higher Fetuin-A values and less frequently NAFLD than PAD patients; (2) NAFLD was positively associated with Fetuin-A values; however, this association was limited to CAD patients only; (3) Fetuin-A values were positively associated with both CAD and NAFLD.

CONCLUSION

The pathogenic interplay of NAFLD, Fetuin-A and atherosclerosis probably varies according to the arterial site.

Ultrasonographic fatty liver indicator detects mild steatosis and correlates with metabolic/histological parameters in various liver diseases

BACKGROUND AND AIMS

Fatty liver is a common feature of different types of liver diseases. The sensitivity and specificity of ultrasonography for diagnosing fatty liver are variable. A semi-quantitative ultrasound score, i.e., the ultrasonographic fatty liver indicator (US-FLI), is closely associated with metabolic/histological variables in patients with nonalcoholic fatty liver disease (NAFLD). The main aims of this study were to assess the diagnostic performance of US-FLI in detecting varying degrees of histological steatosis, and to examine the association of US-FLI with metabolic/histological parameters in 352 biopsied patients with various chronic liver diseases (173 with hepatitis C [HCV], 23 with hepatitis B [HBV], 123 with NAFLD and 33 with other etiologies).

RESULTS

US-FLI accurately detected mild steatosis (minimum amount 10% on histology) with a cut-off value ≥2 (sensitivity 90.1%, specificity 90%), moderate steatosis (≥30%) with a cut-off value ≥3 (sensitivity 86.4%, specificity 92.5%) and severe steatosis (>66%) with a cut-off value ≥5 (sensitivity 88.5%, specificity 87%). US-FLI was correlated with steatosis percentage in each liver disease group as well as with lobular inflammation, ballooning, portal fibrosis, grading and staging in patients with NAFLD or HCV. US-FLI was also correlated with waist circumference, body mass index and insulin resistance both in the whole sample and in each liver disease group.

CONCLUSIONS

US-FLI accurately identifies histological severity and is correlated with metabolic parameters in patients with various steatogenic liver diseases. US-FLI is an easy and versatile tool for the screening of steatosis and the metabolic health of these patients.

Clinical features and natural history of cryptogenic cirrhosis compared to hepatitis C virus-related cirrhosis

AIM

To characterize natural history of cryptogenic cirrhosis (CC) and compare its clinical features and outcomes to those of hepatitis C virus (HCV)-related cirrhosis.

METHODS

A prospective cohort of 102 consecutive patients at their first diagnosis of CC were enrolled in this study. The clinical data and outcomes were compared to an age- and Child-Pugh class-matched cohort of 110 patients with HCV-related cirrhosis. Diagnosis of cirrhosis was based on compatible clinical and laboratory parameters, ultrasound/endoscopic parameters and, whenever possible, on histological grounds and transient elastography. All cases of cirrhosis without a definite etiology were enrolled in the CC group. The parameters assessed were: (1) severity of liver disease at the time of first diagnosis; (2) liver decompensation during follow-up; (3) hepatocellular carcinoma (HCC); (4) orthotopic liver transplantation; and (5) death. The independent associated factors were evaluated by multiple logistic regression analysis, and survival and its determinants by the Kaplan-Meier model, log-rank test and Cox regression.

RESULTS

At the first observation, median age was 66 and 65 years and male gender was 36% and 58% for CC and HCV cirrhosis, respectively. CC showed Child-Pugh class A/B/C of 47%/31%/22%, respectively. Compared to HCV cirrhosis, CC exhibited a significantly higher prevalence of metabolic syndrome (12% vs 54%, respectively), overweight/obesity, high BMI, impaired glucose tolerance, high blood pressure, dyslipidemia, hyperuricemia, cardiovascular diseases, extrahepatic cancer, and gallstones. Over a median period of 42 mo of follow-up, liver decompensation, HCC development and death for CC and HCV-related cirrhosis were 60.8%, and 54.4%, 16.7% and 17.2%, 39.2% and 30%, respectively. The median survival was 60 mo for CC. Independent predictors of death were age and Child-Pugh class at diagnosis. CC showed an approximately twofold higher incidence of HCC in Child-Pugh class A.

CONCLUSION

Undiagnosed nonalcoholic fatty liver disease has an etiologic role in CC that is associated with a poor prognosis, early HCC development, high risk of cardiovascular disease and extrahepatic cancer.

Telomere length elongation after weight loss intervention in obese adults

INTRODUCTION

Telomeres may be considered markers of biological aging, shorter telomere length is associated with some age-related diseases; in several studies short telomere length has also been associated to obesity in adults and adolescents. However the relationship between telomere complex functions and obesity is still not clear. Aim of the study was to assess telomere length (TL) in adults' obese subjects before and after weight loss obtained by placement of bioenteric intragastric balloon (BIB) for 6months.

METHODS

We enrolled 42 obese subjects before and after BIB placement as weight loss intervention. Blood samples were collected in order to obtain DNA from leukocyte to measure TL by quantitative PCR.

RESULTS

Data were analyzed only in 37 subjects with complete data; all presented important body weight loss (124.06±26.7 vs 105.40±23.14, p<0.001) and more interesting they presented a significant increase in TL (3.58±0.83 vs 5.61±3.29, p<0.001). Moreover we observed a significant positive correlation between TL elongation and weight loss (r=0.44, p=0.007) as well as an inverse correlation between TL at baseline and TL elongation (r=-0.35, p=0.03).The predictors of TL elongation were once again weight loss and short TL at baseline (respectively p=0.007 and p=0.003).

CONCLUSIONS

Our study shows that weight loss is associated to telomere lengthening in a positive correlation: the greater weight loss the greater telomere lengthening; moreover telomere lengthening is more significant in those subjects with shortest telomeres at baseline.

Nonalcoholic fatty liver disease is associated with an almost twofold increased risk of incident type 2 diabetes and metabolic syndrome. Evidence from a systematic review and meta-analysis

BACKGROUND AND AIM

The magnitude of the risk of incident type 2 diabetes (T2D) and metabolic syndrome (MetS) among patients with nonalcoholic fatty liver disease (NAFLD) is poorly known. We gauged the risk of developing T2D and MetS in patients with NAFLD diagnosed by either serum liver enzymes (aminotransferases or gamma-glutamyltransferase [GGT]) or ultrasonography.

METHODS

Pertinent prospective studies were identified through extensive electronic database research, and studies fulfilling enrolment criteria were included in the meta-analysis.

RESULTS

Overall, in a pooled population of 117020 patients (from 20 studies), who were followed-up for a median period of 5 years (range: 3-14.7 years), NAFLD was associated with an increased risk of incident T2D with a pooled relative risk of 1.97 (95% confidence interval [CI], 1.80-2.15) for alanine aminotransferase, 1.58 (95% CI, 1.43-1.74) for aspartate aminotransferase, 1.86 (95% CI, 1.71-2.03) for GGT (last vs first quartile or quintile), and 1.86 (95% CI, 1.76-1.95) for ultrasonography, respectively. Overall, in a pooled population of 81411 patients (from eight studies) who were followed-up for a median period of 4.5 years (range: 3-11 years), NAFLD was associated with an increased risk of incident MetS with a pooled relative risk of 1.80 (95% CI, 1.72-1.89) for alanine aminotransferase (last vs first quartile or quintile), 1.98 (95% CI, 1.89-2.07) for GGT, and 3.22 (95% CI, 3.05-3.41) for ultrasonography, respectively.

CONCLUSIONS

Nonalcoholic fatty liver disease, as diagnosed by either liver enzymes or ultrasonography, significantly increases the risk of incident T2D and MetS over a median 5-year follow-up.

Type 2 Diabetes in Non-Alcoholic Fatty Liver Disease and Hepatitis C Virus Infection--Liver: The "Musketeer" in the Spotlight

The pathogenesis of type 2 diabetes (T2D) involves chronic hyperinsulinemia due to systemic and hepatic insulin resistance (IR), which if uncorrected, will lead to progressive pancreatic beta cell failure in predisposed individuals. Non-alcoholic fatty liver disease (NAFLD) encompasses a spectrum of fatty (simple steatosis and steatohepatitis) and non-fatty liver changes (NASH-cirrhosis with or without hepatocellular carcinoma (HCC)) that are commonly observed among individuals with multiple metabolic derangements, notably including visceral obesity, IR and T2D. Hepatitis C virus (HCV) infection is also often associated with both hepatic steatosis and features of a specific HCV-associated dysmetabolic syndrome. In recent years, the key role of the steatotic liver in the development of IR and T2D has been increasingly recognized. Thus, in this comprehensive review we summarize the rapidly expanding body of evidence that links T2D with NAFLD and HCV infection. For each of these two liver diseases with systemic manifestations, we discuss the epidemiological burden, the pathophysiologic mechanisms and the clinical implications. To date, substantial evidence suggests that NAFLD and HCV play a key role in T2D development and that the interaction of T2D with liver disease may result in a "vicious circle", eventually leading to an increased risk of all-cause mortality and liver-related and cardiovascular complications. Preliminary evidence also suggests that improvement of NAFLD is associated with a decreased incidence of T2D. Similarly, the prevention of T2D following HCV eradication in the era of direct-acting antiviral agents is a biologically plausible result. However, additional studies are required for further clarification of mechanisms involved.

The Role of Nuclear Receptors in the Pathophysiology, Natural Course, and Drug Treatment of NAFLD in Humans

Nonalcoholic fatty liver disease (NAFLD) describes steatosis, nonalcoholic steatohepatitis with or without fibrosis, and hepatocellular carcinoma, namely the entire alcohol-like spectrum of liver disease though observed in the nonalcoholic, dysmetabolic, individual free of competing causes of liver disease. NAFLD, which is a major public health issue, exhibits intrahepatic triglyceride storage giving rise to lipotoxicity. Nuclear receptors (NRs) are transcriptional factors which, activated by ligands, are master regulators of metabolism and also have intricate connections with circadian control accounting for cyclical patterns in the metabolic fate of nutrients. Several transcription factors, such as peroxisome proliferator-activated receptors, liver X receptors, farnesoid X receptors, and their molecular cascades, finely regulate energetic fluxes and metabolic pathways. Dysregulation of such pathways is heavily implicated in those metabolic derangements characterizing insulin resistance and metabolic syndrome and in the histogenesis of progressive NAFLD forms. We review the role of selected NRs in NAFLD pathogenesis. Secondly, we analyze the role of NRs in the natural history of human NAFLD. Next, we discuss the results observed in humans following administration of drug agonists or antagonists of the NRs pathogenically involved in NAFLD. Finally, general principles of treatment and lines of research in human NAFLD are briefly examined.

Nonalcoholic fatty liver disease and aging: Epidemiology to management

Nonalcoholic fatty liver disease (NAFLD) is common in the elderly, in whom it carries a more substantial burden of hepatic (nonalcoholic steatohepatitis, cirrhosis and hepatocellular carcinoma) and extra-hepatic manifestations and complications (cardiovascular disease, extrahepatic neoplasms) than in younger age groups. Therefore, proper identification and management of this condition is a major task for clinical geriatricians and geriatric hepatologists. In this paper, the epidemiology and pathophysiology of this condition are reviewed, and a full discussion of the link between NAFLD and the aspects that are peculiar to elderly individuals is provided; these aspects include frailty, multimorbidity, polypharmacy and dementia. The proper treatment strategy will have to consider the peculiarities of geriatric patients, so a multidisciplinary approach is mandatory. Non-pharmacological treatment (diet and physical exercise) has to be tailored individually considering the physical limitations of most elderly people and the need for an adequate caloric supply. Similarly, the choice of drug treatment must carefully balance the benefits and risks in terms of adverse events and pharmacological interactions in the common context of both multiple health conditions and polypharmacy. In conclusion, further epidemiological and pathophysiological insight is warranted. More accurate understanding of the molecular mechanisms of geriatric NAFLD will help in identifying the most appropriate diagnostic and therapeutic approach for individual elderly patients.

Pathogenesis and significance of hepatitis C virus steatosis: An update on survival strategy of a successful pathogen

Hepatitis C virus (HCV) is a successful pathogen on the grounds that it exploits its host’s metabolism to build up viral particles; moreover it favours its own survival by inducing chronic disease and the development of specific anatomic changes in the infected organ. Steatosis, therefore, is associated with HCV infection by necessity rather than by chance alone. Approximately 6% of HCV patients have steatohepatitis. Interestingly, HCV steatosis occurs in the setting of multiple metabolic abnormalities (hyperuricemia, reversible hypocholesterolemia, insulin resistance, arterial hypertension and expansion of visceral adipose tissue) collectively referred to as “hepatitis C-associated dysmetabolic syndrome” (HCADS). General, nonalcoholic fatty liver disease (NAFLD)-like, mechanisms of steatogenesis (including increased availability of lipogenic substrates and de novo lipogenesis; decreased oxidation of fatty substrates and export of fatty substrates) are shared by all HCV genotypes. However, genotype 3 seemingly amplifies such steatogenic molecular mechanisms reported to occur in NAFLD via more profound changes in microsomal triglyceride transfer protein; peroxisome proliferator-activated receptor alpha; sterol regulatory element-binding proteins and phosphatase and tensin homologue. HCV steatosis has a remarkable clinical impact in as much as it is an acknowledged risk factor for accelerated fibrogenesis; for impaired treatment response to interferon and ribavirin; and development of hepatocellular carcinoma. Recent data, moreover, suggest that HCV-steatosis contributes to premature atherogenesis via both direct and indirect mechanisms. In conclusion, HCV steatosis fulfills all expected requirements necessary to perpetuate the HCV life cycle. A better understanding of the physiology of HCADS will likely result in a more successful handling of disease with improved antiviral success rates.

Age-associated alterations in cholesterol homeostasis: evidence from a cross-sectional study in a Northern Italy population

Background

The modifications of cholesterol metabolism associated with aging are ill-defined. The objective of this study was to define age-associated alterations of the different metabolic pathways controlling cholesterol homeostasis by analyzing circulating sterols.

Methods

We analyzed serum samples collected from 201 adult (75 male, 126 female) subjects within the epidemiological MICOL study (Multicentrica Italiana Colelitiasi). The age range was 38–79 years; 103 had evidence of gallstones. The concentrations of the different sterols, recognized as markers of the main pathways of cholesterol homeostasis, were analyzed by gas chromatography-mass spectrometry, including lathosterol (synthesis), campesterol and sitosterol (absorption), and 7α-hydroxy-4-cholesten-3-one (degradation to bile acids).

Results

A significant direct correlation was detected between age and cholesterol levels (r =0.34, P<0.01). The lathosterol/cholesterol ratio was lower in older age quartiles (P<0.05 by analysis of variance), with an inverse correlation between the lathosterol/cholesterol ratio and age (r=−0.32, P<0.01). Such correlation was particularly evident in females. The campesterol/cholesterol and sitosterol/cholesterol ratios were inversely correlated with aging in control, but not in gallstone patients. The levels of 7α-hydroxy-4-cholesten-3-one were not correlated with age.

Conclusion

These data show a reduction of cholesterol synthesis with aging which is associated with increased circulating cholesterol levels. The finding might be related to a reduced metabolic need for cholesterol in advancing age, leading to a downregulation of the main mechanisms of cholesterol intake in the liver. A different age-related behavior was observed in gallstone-free versus gallstone patients regarding cholesterol absorption. The possible implications in terms of the pharmacological management of hypercholesterolemia in the elderly remain to be defined.

Classical and innovative insulin sensitizing drugs for the prevention and treatment of NAFLD

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD), the most common chronic liver disorder worldwide, comprises a spectrum of conditions ranging from simple steatosis to nonalcoholic steatohepatitis (NASH) and cirrhosis. NASH is associated with an increased risk of hepatocellular carcinoma (HCC) and cardiometabolic disease. Insulin resistance (IR) is the underlying pathogenic mechanism for NAFLD, the presence of which in turn, is a strong predictor for the development of metabolic disorders. Hence, therapy of NAFLD with insulin-sensitizing drugs (ISDs) should ideally improve the key hepatic histological changes (steatosis, inflammation and fibrosis), but should also reduce cardiometabolic and cancer risk.

OBJECTIVES

In this review, the rationale for the use of ISDs and the evidence for their efficacy are detailed. In particular, the mechanism of action, potential for use, limitations and untoward effects of metformin and thiazolidinediones are systematically reviewed. Further, we discuss novel ISDs that may have potential clinical utility in NAFLD.

RESULTS AND CONCLUSION

Despite the theoretical prediction that ISDs might have beneficial effects on disease outcomes, evidence that ISDs are able to alter the natural history of NAFLD are presently not available. The exploration of novel strategies exploiting "nonconventional" ISDs is encouraged.

Relationship of serum fetuin-A levels with coronary atherosclerotic burden and NAFLD in patients undergoing elective coronary angiography

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) patients are prone to coronary artery disease (CAD). Fetuin-A inhibits arterial calcification, induces insulin resistance, and is increased in NAFLD. Data on fetuin-A levels in CAD are conflicting. We tried to ascertain whether NAFLD and CAD are associated and if fetuin-A predicts CAD and/or NAFLD.

METHODS

CAD was diagnosed by ≥50% stenosis in coronary arteries and NAFLD by ultrasound imaging in the absence of any other liver disease. Seventy patients who underwent elective coronarography at our hospital were recruited in this cross-sectional study. Twenty-four patients had no CAD (9 with and 15 without NAFLD) and 46 had CAD (20 with and 26 without NAFLD). Standard anthropometric indices and metabolic parameters were recorded. Fetuin-A was determined by enzyme-linked immunosorbent assay (ELISA). Visceral fat thickness and visceral/subcutaneous fat ratio were assessed by ultrasonography.

RESULTS

NAFLD was not associated with CAD, probably owing to the limited series. Fetuin-A was significantly lower, whereas visceral fat thickness and visceral/subcutaneous fat ratio were higher in patients with CAD versus those without CAD. Younger age and higher body mass index (BMI), waist circumference, triglycerides, fasting glucose, homeostasis model assessment, spleen area, subcutaneous fat thickness, and prevalence of metabolic derangements were associated with NAFLD. At multivariate analysis, elevated fetuin-A levels were an independent negative predictor of CAD [odds ratio (OR)=0.995, P=0.049]. Fetuin-A was an independent predictor of NAFLD (OR=1.005, P=0.036) in the model including BMI.

CONCLUSIONS

This prospective cross-sectional study demonstrates high fetuin-A levels to be independently associated with NAFLD and a lower risk of coronarographically diagnosed CAD.

Concomitant high gene copy number and protein overexpression of IGF1R and EGFR negatively affect disease-free survival of surgically resected non-small-cell-lung cancer patients

BACKGROUND

Insulin-like growth factor 1 receptor (IGF1R) represents a novel molecular target in non-small-cell-lung cancer (NSCLC). IGF1R and epidermal growth factor receptor (EGFR) activation are essential to mediate tumor cell survival, proliferation, and invasion. This study investigates the prognostic role of IGF1R and EGFR in surgically resected NSCLC.

MATERIALS AND METHODS

IGF1R and EGFR copy number gain (CNG) were tested by fluorescence in situ hybridization (FISH) and protein expression by immunohistochemistry (IHC) in 125 stage I-II-IIIA NSCLC patients.

RESULTS

Fourty-six tumors (40.3%) were IGF1R FISH-positive (FISH+), and 76 (67.2%) were EGFR FISH+. Tumors with concomitant IGF1R/EGFR FISH+ were observed in 34 cases (30.1%). IGF1R and EGFR FISH+ were associated with SCC histology (p = 0.01 and p = 0.04, respectively). IGF1R and EGFR protein over-expression (IHC+) were detected in 45 (36.0%) and 69 (55.2%) cases, respectively. Tumors with concomitant IGF1R/EGFR IHC+ were detected in 31 (24.8%) patients. IGF1R/EGFR FISH+ and IGF1R/EGFR IHC+ were significantly associated (χ(2) = 4.02, p = 0.04). Patients with IGF1R/EGFR FISH+ and IGF1R/EGFR IHC+ were associated with shorter disease-free survival (DFS) (p = 0.05 and p = 0.05, respectively). Patients with concomitant IGF1R/EGFR FISH+/IHC+ had a worse DFS and overall survival (p = 0.005 and p = 0.01, respectively). The multivariate model confirmed that IGF1R/EGFR FISH+/IHC+ (hazard ratio (HR), 4.08; p = 0.01) and tumor stage (II-III vs I) (HR, 4.77; p = 0.003) were significantly associated with worse DFS.

CONCLUSIONS

IGF1R/EGFR FISH+ correlates with IGF1R/EGFR IHC+. IGF1R/EGFR FISH+/IHC+ is an independent negative prognostic factor for DFS in early NSCLC. These features may have important implications for future anti-IGF1R therapeutic approaches.

Increased appearance rate of 27-hydroxycholesterol in vivo in hypercholesterolemia: a possible compensatory mechanism

BACKGROUND AND AIMS

The first step in the alternative pathway of bile acid biosynthesis is the 27-hydroxylation of cholesterol, which takes place both in liver and extrahepatic tissues. This pathway is believed to play a role in peripheral cholesterol degradation. Aim of this study was to investigate the impact of hyperlipidemia on 27-hydroxycholesterol appearance rate, and to assess the effects induced by treatment with statins.

METHODS AND RESULTS

Seven patients with familial hypercholesterolemia and eight patients with familial combined hyperlipidemia underwent determination of 27-hydroxylation rates in vivo by i.v. infusion of deuterated 27-hydroxycholesterol. Isotope enrichment was assayed by gas chromatography-mass spectrometry, allowing to calculate 27-hydroxycholesterol appearance rates. Six normocholesterolemic subjects were regarded as controls. In some hypercholesterolemic patients the infusions were repeated during treatment with atorvastatin or rosuvastatin. Hydroxylation rates were higher in hypercholesterolemic patients (8.7 ± 2.5 mg/h; controls, 3.4 ± 2.0 mg/h; combined hyperlipidemia, 4.4 ± 1.6 mg/h; mean ± SD, P < 0.01 vs both). After statin treatment, both plasma cholesterol levels and hydroxylation rates dropped by nearly 50%. No difference was detectable between the two statins. A linear correlation was shown between plasma cholesterol and 27-hydroxylation rates.

CONCLUSION

Hypercholesterolemia associates with increased 27-hydroxycholesterol appearance rates, which decrease during hypocholesterolemic treatment. The correlation with cholesterol levels supports the view that 27-hydroxylation may act as a compensatory mechanism in a condition of larger plasma cholesterol pool. A regulatory role for hepatic and extrahepatic nuclear receptors seems reasonable. These data prompt novel pharmacological approaches for the management of hypercholesterolemia and the prevention of atherosclerosis.

Are maternal mitochondria the selfish entities that are masters of the cells of eukaryotic multicellular organisms?

The Energide concept, as well as the endosymbiotic theory of eukaryotic cell organization and evolution, proposes that present-day cells of eukaryotic organisms are mosaics of specialized and cooperating units, or organelles. Some of these units were originally free-living prokaryotes, which were engulfed during evolutionary time. Mitochondria represent one of these types of previously independent organisms, the Energide, is another type. This new perspective on the organization of the cell has been further expanded to reveal the concept of a public milieu, the cytosol, in which Energides and mitochondria live, each with their own private internal milieu. The present paper discusses how the endosymbiotic theory implicates a new hypothesis about the hierarchical and communicational organization of the integrated prokaryotic components of the eukaryotic cell and provides a new angle from which to consider the theory of evolution and its bearing upon cellular complexity. Thus, it is proposed that the "selfish gene" hypothesis of Dawkins1 is not the only possible perspective for comprehending genomic and cellular evolution. Our proposal is that maternal mitochondria are the selfish "master" entities of the eukaryotic cell with respect not only to their propagation from cell-to-cell and from generation-to-generation but also to their regulation of all other cellular functions. However, it should be recognized that the concept of "master" and "servant" cell components is a metaphor; in present-day living organisms their organellar components are considered to be interdependent and inseparable.

Neurosteroids and epileptogenesis in the pilocarpine model: evidence for a relationship between P450scc induction and length of the latent period

PURPOSE

Cytochrome P450 cholesterol side-chain cleavage enzyme (P450scc) catalyzes the initial step in the biosynthesis of neurosteroids within the brain. We sought to determine which cells express P450cc and whether neurosteroids play a role in the regulation of epileptogenesis following pilocarpine-induced status epilepticus (SE).

METHODS

Rats experienced uninterrupted SE or SE terminated with diazepam at 60, 120, and 180 min. P450scc induction in CA3 hippocampus was determined by double immunolabeling with P450scc antiserum and monoclonal antibodies against GFAP (astrocytes), RIP (oligodendrocytes), or heme oxygenase-1 (microglia).

RESULTS

SE was associated with P450scc induction in many astrocytes and a small number of microglia and oligodendrocytes in the hippocampal CA3 strata radiatum and lacunosum-moleculare. The extent of P450scc induction increased with increasing SE duration. Paradoxically, increased P450scc induction in rats experiencing SE for 180 min or more was associated with the delayed onset of spontaneous recurrent seizures. Treatment with the 5 alpha-reductase inhibitor finasteride (100 mg/kg/day for 25 days), which inhibits the synthesis of gamma-aminobutyric acid (GABA)(A) receptor modulating neurosteroids such as allopregnanolone, was associated with a significant reduction in time to the onset of spontaneous seizures in rats exposed to 180-min but not 90-min SE.

DISCUSSION

P450scc is induced by SE in a diverse population of hippocampal glia. Induction of P450scc is associated with the delayed onset of spontaneous seizures. Conversely, inhibition of neurosteroid synthesis accelerated the onset of spontaneous seizures, but only in animals exhibiting significant increases in P450scc. These findings suggest that induction of neurosteroid synthesis in reactive glial cells is associated with delayed onset of spontaneously recurrent seizures.

Network hyperexcitability within the deep layers of the pilocarpine-treated rat entorhinal cortex

In this study we report that in the presence of normal buffer, epileptiform discharges occur spontaneously (duration = 2.60 +/- 0.49 s) or can be induced by electrical stimuli (duration = 2.50 +/- 0.62 s) in the entorhinal cortex (EC) of brain slices obtained from pilocarpine-treated rats but not in those from age-matched, nonepileptic control (NEC) animals. These network-driven epileptiform events consist of field oscillatory sequences at frequencies greater than 200 Hz that most often initiate in the lateral EC and propagate to the medial EC with 4-63 ms delays. The NMDA receptor antagonist CPP depresses the rate of occurrence (P < 0.01) of these spontaneous epileptiform discharges but fails in blocking them. Paradoxically, stimulus-induced epileptiform responses are enhanced in duration during CPP application. However, concomitant application of NMDA and non-NMDA glutamatergic antagonists abolishes spontaneous and stimulus-induced epileptiform events. Intracellular recordings from lateral EC layer V cells indicate a lower frequency of spontaneous hyperpolarizing postsynaptic potentials in pilocarpine-treated tissue than in NEC (P < 0.002) both under control conditions and with glutamatergic receptor blockade; the reversal potential of pharmacologically isolated GABA(A) receptor-mediated inhibitory postsynaptic potentials has similar values in the two types of tissue. Finally, immunohistochemical analysis shows that parvalbumin-positive interneurons are selectively reduced in number in EC deep layers. Collectively, these results indicate that reduced inhibition within the pilocarpine-treated EC layer V may promote network epileptic hyperexcitability.

Endogenous neurosteroids modulate epileptogenesis in a model of temporal lobe epilepsy

Neurosteroids modulate seizure susceptibility, but their role in the regulation of epileptogenesis is unknown. Status epilepticus (SE) induces temporal lobe epileptogenesis following a latent period in which glial cells are activated. Here, we found that P450scc, the rate-limiting enzyme in steroid synthesis, is upregulated in hippocampal glia during the latent period after pilocarpine-induced SE in rats. More prolonged SE was associated with greater P450scc expression and longer latencies to the development of seizures, suggesting that enhanced steroid synthesis retards epileptogenesis. The 5alpha-reductase inhibitor finasteride, which blocks neurosteroid synthesis, reduced the latent period, indicating that glia-derived neurosteroids may be antiepileptogenic.

Impaired activation of CA3 pyramidal neurons in the epileptic hippocampus

We employed in vitro and ex vivo imaging tools to characterize the function of limbic neuron networks in pilocarpine-treated and age-matched, nonepileptic control (NEC) rats. Pilocarpine-treated animals represent an established model of mesial temporal lobe epilepsy. Intrinsic optical signal (IOS) analysis of hippocampal-entorhinal cortex (EC) slices obtained from epileptic rats 3 wk after pilocarpine-induced status epilepticus (SE) revealed hyperexcitability in many limbic areas, but not in CA3 and medial EC layer III. By visualizing immunopositivity for FosB/DeltaFosB-related proteins which accumulate in the nuclei of neurons activated by seizures we found that: (1) 24 h after SE, FosB/DeltaFosB immunoreactivity was absent in medial EC layer III, but abundant in dentate gyrus, hippocampus proper (including CA3) and subiculum; (2) FosB/DeltaFosB levels progressively diminished 3 and 7 d after SE, whereas remaining elevated (p < 0.01) in subiculum; (3) FosB/DeltaFosB levels sharply increased 2 wk after SE (and remained elevated up to 3 wk) in dentate gyrus and in most of the other areas but not in CA3. A conspicuous neuronal damage was noticed in medial EC layer III, whereas hippocampus was more preserved. IOS analysis of the stimulus-induced responses in slices 3 wk after SE demonstrated that IOSs in CA3 were lower (p < 0.05) than in NEC slices following dentate gyrus stimulation, but not when stimuli were delivered in CA3. These findings indicate that CA3 networks are hypoactive in comparison with other epileptic limbic areas. We propose that this feature may affect the ability of hippocampal outputs to control epileptiform synchronization in EC.

Subiculum network excitability is increased in a rodent model of temporal lobe epilepsy

In this study, we used in vitro electrophysiology along with immunohistochemistry and molecular techniques to study the subiculum--a limbic structure that gates the information flow from and to the hippocampus--in pilocarpine-treated epileptic rats. Comparative data were obtained from age-matched nonepileptic controls (NEC). Subicular neurons in hippocampal-entorhinal cortex (EC) slices of epileptic rats were: (i) hyperexcitable when activated by CA1 or EC inputs; and (ii) generated spontaneous postsynaptic potentials at higher frequencies than NEC cells. Analysis of pharmacologically isolated, GABA(A) receptor-mediated inhibitory postsynaptic potentials revealed more positive reversal potentials in epileptic tissue (-67.8 +/- 6.3 mV, n = 16 vs. -74.8 +/- 3.6 mV in NEC, n = 13; P < 0.001) combined with a reduction in peak conductance (17.6 +/- 11.3 nS vs. 41.1 +/- 26.7 nS in NEC; P < 0.003). These electrophysiological data correlated in the epileptic subiculum with (i) reduced levels of mRNA expression and immunoreactivity of the neuron-specific potassium-chloride cotransporter 2; (ii) decreased number of parvalbumin-positive cells; and (iii) increased synaptophysin (a putative marker of sprouting) immunoreactivity. These findings identify an increase in network excitability within the subiculum of pilocarpine-treated, epileptic rats and point at a reduction in inhibition as an underlying mechanism.