Free radical biology for medicine: learning from nonalcoholic fatty liver disease

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Redox cell signaling and hepatic progenitor cells.

Hepatic diseases are widespread in the world and organ transplantation is currently the only treatment for liver failure. New cell-based approaches have been considered, since stem cells may represent a possible source to treat liver diseases. Acute and chronic liver diseases are characterized by high production of reactive oxygen and nitrogen species, with consequent oxidative modifications of cellular macromolecules and alteration of signaling pathways, metabolism and cell cycle. Although considered harmful molecules, reactive species are involved in cell growth and differentiation processes, modulating the activity of transcription factors, which take part in stemness/proliferation. It is conceivable that redox balance may regulate the development of hepatic progenitor cells, function and survival in synchrony with metabolism during chronic liver diseases. This review aims to summarize diverse redox-sensitive signaling pathways involved in stem cell fate, highlighting the important role of hepatic progenitor cells as a possible source to treat end-stage liver disease for organ regeneration

Analogs in the treatment of chronic hepatitis B: real life experience with tenofovir and entecavir

INTRODUCTION: Tenofovir and entecavir are potent antiviral agents. By suppressing viral replication, they induce histological improvement and finally delay the progression of chronic hepatitis B and the development of complications. They are rarely associated with serious side effects. Our data from a real life experience support data from the literature and suggest some minimal difference that may be useful in tailoring therapy.PATIENTS AND METHODS: We retrospectively analyzed 54 patients affected by chronic hepatitis B (31 and 23 treated by entecavir and tenofovir, respectively). Eight patients were cirrhotic. At baseline and 4-12 and 24 weeks after starting therapy, biochemical and virological analysis were performed in all patients. Renal function tests (serum creatinine, creatinine clearance and blood urea), serum (calcium and phosphate blood level) and urine electrolyte were also studied.RESULTS: All the patients reached virological control within 24 weeks. Only in the group treated by tenofovir we observed a complete viral suppression within 12 weeks. Some patients treated with tenofovir showed increased creatinine clearance without serum creatinine alteration. No significant side effects were reported with the exception of one case of persistent headache in the entecavir group for which the drug was suspended.CONCLUSIONS: Entecavir and tenofovir are effective in suppressing viral replication in patients with chronic hepatitis B. Tenofovir is more potent than entecavir and viral replication is blocked within 12 weeks of therapy. Tenofovir administration is associated with slight increase of creatinine clearance without alteration of serum creatinine levels. The choice of one or the other should be made according to target and specific patients characteristics. In patients with high serum viral load where the complete and quick control of viral replication is the main target, tenofovir may represent the best choice

Alterations of clock gene RNA expression in brain Regions of a triple transgenic model of Alzheimer's Disease

A disruption to circadian rhythmicity and the sleep/wake cycle constitutes a major feature of Alzheimer's disease (AD). The maintenance of circadian rhythmicity is regulated by endogenous clock genes and a number of external Zeitgebers, including light. This study investigated the light induced changes in the expression of clock genes in a triple transgenic model of AD (3×Tg-AD) and their wild type littermates (Non-Tg). Changes in gene expression were evaluated in four brain areas¾suprachiasmatic nucleus (SCN), hippocampus, frontal cortex and brainstem¾of 6- and 18-month-old Non-Tg and 3×Tg-AD mice after 12 h exposure to light or darkness. Light exposure exerted significant effects on clock gene expression in the SCN, the site of the major circadian pacemaker. These patterns of expression were disrupted in 3×Tg-AD and in 18-month-old compared with 6-month-old Non-Tg mice. In other brain areas, age rather than genotype affected gene expression; the effect of genotype was observed on hippocampal Sirt1 expression, while it modified the expression of genes regulating the negative feedback loop as well as Rorα, Csnk1ɛ and Sirt1 in the brainstem. In conclusion, during the early development of AD, there is a disruption to the normal expression of genes regulating circadian function after exposure to light, particularly in the SCN but also in extra-hypothalamic brain areas supporting circadian regulation, suggesting a severe impairment of functioning of the clock gene pathway. Even though this study did not demonstrate a direct association between these alterations in clock gene expression among brain areas with the cognitive impairments and chrono-disruption that characterize the early onset of AD, our novel results encourage further investigation aimed at testing this hypothesis

seborrhoeic dermatitis in the elderly inferences on the possible role of disability and loss of self sufficiency

The constant increase of life expectancy in countries with high standards of living raises growing concern about many aspects of skin morbidity in the elderly. As regards seborrhoeic dermatitis, literature yields prevalence estimates for elderly people that are consistently higher than those reported from the general population. This prompts speculations on whether factors inherently involved in senescence might have some role in the course of seborrhoeic dermatitis. In a series of 186 subjects, aged §65, strength of association of the skin disorder with age, sex, coexisting non-cutaneous conditions, and degree of loss of self-sufficiency in activities of daily living (ADL index) was evaluated by univariate and multivariate analysis. We found that age (OR: 1.14; pv0.001) and, more importantly, dependency in more than one ADL (OR: 30.2; pv0.0001) were independent explanatory variables of seborrhoeic dermatitis. These findings suggest that senescence per se might have some significance in the natural history of this type of eczema. Key words: seborrhoeic dermatitis; old age; senescence; disability; ADL index; odds ratio

Synergistic interaction of fatty acids and oxysterols impairs mitochondrial function and limits liver adaptation during nafld progression

The complete mechanism accounting for the progression from simple steatosis to steatohepatitis in nonalcoholic fatty liver disease (NAFLD) has not been elucidated. Lipotoxicity refers to cellular injury caused by hepatic free fatty acids (FFAs) and cholesterol accumulation. Excess cholesterol autoxidizes to oxysterols during oxidative stress conditions. We hypothesize that interaction of FAs and cholesterol derivatives may primarily impair mitochondrial function and affect biogenesis adaptation during NAFLD progression. We demonstrated that the accumulation of specific non-enzymatic oxysterols in the liver of animals fed high-fat+high-cholesterol diet induces mitochondrial damage and depletion of proteins of the respiratory chain complexes. When tested in vitro, 5α-cholestane-3β,5,6β-triol (triol) combined to FFAs was able to reduce respiration in isolated liver mitochondria, induced apoptosis in primary hepatocytes, and down-regulated transcription factors involved in mitochondrial biogenesis. Finally, a lower protein content in the mitochondrial respiratory chain complexes was observed in human non-alcoholic steatohepatitis. In conclusion, hepatic accumulation of FFAs and non-enzymatic oxysterols synergistically facilitates development and progression of NAFLD by impairing mitochondrial function, energy balance and biogenesis adaptation to chronic injury

Direct‐acting antivirals for HCV treatment in older patients: A systematic review and meta‐analysis

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Vascular risk and genetics of sporadic late-onset Alzheimer's disease.

In recent years, it is becoming apparent that genes may play an important role in the development of late-onset Alzheimer’s disease (LOAD), and genetic studies could unravel new clues. Based on a growing vascular hypothesis for the pathogenesis of LOAD and other dementias, there is increasing interest for environmental and genetic vascular factors. Polymorphisms in different susceptibility genes already implicated in vascular disease risk are now also being suggested as possible genetic markers for increased risk of developing LOAD; however, many of these studies have shown conflicting results. Thus far, the apolipoprotein E (APOE) gene seems to be the only vascular susceptibility factor that is agreed to play a role in the multifactorial pathogenesis of AD although emerging genetic and biological evidence is now strengthening the case for additional inclusion of angiotensin I-converting enzyme 1 (ACE1) into this category. This review will focus on the current knowledge on genetic and nongenetic vascular factors likely to be involved in LOAD, with special emphasis placed on the APOE and ACE1 genes

Risk of Statin-Induced Hypertransaminasemia: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Objective: To assess the effect of statins compared with placebo on the risk of developing hypertransaminasemia. Patients and methods: We performed a systematic review of electronic databases and included articles published between January 1, 1965, and April 10, 2017. Randomized clinical trials (RCTs) comparing statins vs placebo were included. Odds ratios (ORs) were pooled in random-effect meta-analyses according to established methods recommended by the Cochrane Collaboration. Results: Seventy-three eligible RCTs, comprising 123,051 patients, were identified. Statins associated with a significantly risk of hypertransaminasemia (OR 1.45; 95% confidence interval [CI], 1.24-1.69; P<.001). Atorvastatin showed the highest odds (OR 2.66; 95% CI, 1.74-4.06; P<.001) followed by rosuvastatin (OR 1.35; 95% CI, 1.06-1.70; P=.01) and lovastatin (OR 1.53; 95% CI, 1.03-2.28; P=.04). Pravastatin, fluvastatin, and simvastatin yielded no statistically different odds compared with placebo. Conclusions: A dose-dependent risk of developing hypertransaminasemia occurs in patients taking atorvastatin, rosuvastatin, and lovastatin