Effects of Acetyl-L-Carnitine on Oxidative Stress in Amyotrophic Lateral Sclerosis Patients: Evaluation on Plasma Markers and Members of the Neurovascular Unit

Oxidative stress, the alteration of mitochondrial function, and the neurovascular unit (NVU), play a role in Amyotrophic Lateral Sclerosis (ALS) pathogenesis. We aimed to demonstrate the changes in the plasma redox system and nitric oxide (NO) in 32 new ALS-diagnosed patients in treatment with Acetyl-L-Carnitine (ALCAR) compared to healthy controls. We also evaluated the effects of plasma on human umbilical cord-derived endothelial vascular cells (HUVEC) and astrocytes. The analyses were performed at the baseline (T0), after three months (T1), and after six months (T2). In ALS patients at T0/T1, the plasma markers of lipid peroxidation, thiobarbituric acid reactive substances (TBARS) and 4-hydroxy nonenal (4-HNE) were higher, whereas the antioxidants, glutathione (GSH) and the glutathione peroxidase (GPx) activity were lower than in healthy controls. At T2, plasma TBARS and 4-HNE decreased, whereas plasma GSH and the GPx activity increased in ALS patients. As regards NO, the plasma levels were firmly lower at T0–T2 than those of healthy controls. Cell viability, and mitochondrial membrane potential in HUVEC/astrocytes treated with the plasma of ALS patients at T0–T2 were reduced, while the oxidant release increased. Those results, which confirmed the fundamental role of oxidative stress, mitochondrial function, and of the NVU in ALS pathogenesis, can have a double meaning, acting as disease markers at baseline and potential markers of drug effects in clinical practice and during clinical trial

17,β-estradiol inhibits hepatitis C virus mainly by interference with the release phase of its life cycle

Rationale & Aim: Estrogen and estrogen-mediated signalling protect from hepatitis C virus through incompletely understood mechanisms. We aimed to ascertain which phase(s) of HCV life cycle is/are affected by estrogens. Methods: Huh7 cells infected with the JFH1 virus (genotype 2a) were exposed to dehydroepiandrosterone, testosterone, progesterone and 17β-estradiol (tested with/without its receptor antagonist fulvestrant). Dose-response curves were established to calculate IC50 values. To dissect how 17β-estradiol interferes with phases of HCV life cycle, its effects were measured on the HCV pseudo-particle system (viral entry), the sub-genomic replicon N17/JFH1 and the replicon cell line Huh7-J17 (viral replication). Finally, in a dual-step infection model, infectious supernatants, collected from infected cells exposed to hormones, were used to infect naïve cells. Results: Progesterone and testosterone showed no inhibitory effect on HCV; dehydroepiandrosterone was only mildly inhibitory. In contrast, 17β-estradiol inhibited infection by 64-67% (IC50 values 140 to 160 nM). Fulvestrant reverted the inhibition by 17β-estradiol in a dose-dependent manner. 17β-estradiol exerted only a slight inhibition (<20%) on HCV pseudo-particles, and had no effect on cells either transiently or stably (Huh7-J17 cells) expressing the N17/JFH1 replicon. In the dual-step infection model, a significant IC50 decline occurred between primary (134 nM) and secondary (100 nM) infections (p=0.02), with extracellular HCV RNA and infectivity being reduced to a higher degree in comparison to its intracellular counterpart. Conclusions: 17β-estradiol inhibits HCV acting through its intracellular receptors, mainly interfering with late phases (assembly/release) of the HCV life cycle

Exposure to Plasma From Non-alcoholic Fatty Liver Disease Patients Affects Hepatocyte Viability, Generates Mitochondrial Dysfunction, and Modulates Pathways Involved in Fat Accumulation and Inflammation

Changes of lipidic storage, oxidative stress and mitochondrial dysfunction may be involved in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). Although the knowledge of intracellular pathways has vastly expanded in recent years, the role and mechanisms of circulating triggering factor(s) are debated. Thus, we tested the hypothesis that factors circulating in the blood of NAFLD patients may influence processes underlying the disease. Huh7.5 cells/primary human hepatocytes were exposed to plasma from 12 NAFLD patients and 12 healthy subjects and specific assays were performed to examine viability, H2O2 and mitochondrial reactive oxygen species (ROS) release, mitochondrial membrane potential and triglycerides content. The involvement of NLRP3 inflammasome and of signaling related to peroxisome-proliferator-activating-ligand-receptor-γ (PPARγ), sterol-regulatory-element-binding-protein-1c (SREBP-1c), nuclear-factor-kappa-light-chain-enhancer of activated B cells (NF-kB), and NADPH oxidase 2 (NOX2) was evaluated by repeating the experiments in the presence of NLRP3 inflammasome blocker, MCC950, and through Western blot. The results obtained shown that plasma of NAFLD patients was able to reduce cell viability and mitochondrial membrane potential by about 48 and 24% (p < 0.05), and to increase H2O2, mitochondrial ROS, and triglycerides content by about 42, 19, and 16% (p < 0.05), respectively. An increased expression of SREBP-1c, PPARγ, NF-kB and NOX2 of about 51, 121, 63, and 46%, respectively, was observed (p < 0.05), as well. Those effects were reduced by the use of MCC950. Thus, in hepatocytes, exposure to plasma from NAFLD patients induces a NAFLD-like phenotype by interference with NLRP3-inflammasome pathways and the activation of intracellular signaling related to SREBP-1c, PPARγ, NF-kB and NOX2

Levosimendan: a cardiovascular drug to prevent liver ischemia-reperfusion injury?

INTRODUCTION: Temporary occlusion of the hepatoduodenal ligament leads to an ischemic-reperfusion (IR) injury in the liver. Levosimendan is a new positive inotropic drug, which induces preconditioning-like adaptive mechanisms due to opening of mitochondrial KATP channels. The aim of this study was to examine possible protective effects of levosimendan in a rat model of hepatic IR injury. MATERIAL AND METHODS: Levosimendan was administered to male Wistar rats 1 hour (early pretreatment) or 24 hours (late pretreatment) before induction of 60-minute segmental liver ischemia. Microcirculation of the liver was monitored by laser Doppler flowmeter. After 24 hours of reperfusion, liver and blood samples were taken for histology, immuno- and enzyme-histochemistry (TUNEL; PARP; NADH-TR) as well as for laboratory tests. Furthermore, liver antioxidant status was assessed and HSP72 expression was measured. RESULTS: In both groups pretreated with levosimendan, significantly better hepatic microcirculation was observed compared to respective IR control groups. Similarly, histological damage was also reduced after levosimendan administration. This observation was supported by significantly lower activities of serum ALT (pearly = 0.02; plate = 0.005), AST (pearly = 0.02; plate = 0.004) and less DNA damage by TUNEL test (pearly = 0.05; plate = 0.034) and PAR positivity (pearly = 0.02; plate = 0.04). Levosimendan pretreatment resulted in significant improvement of liver redox homeostasis. Further, significantly better mitochondrial function was detected in animals receiving late pretreatment. Finally, HSP72 expression was increased by IR injury, but it was not affected by levosimendan pretreatment. CONCLUSION: Levosimendan pretreatment can be hepatoprotective and it could be useful before extensive liver resection

Beneficial Effects of Estrogen in a Mouse Model of Cerebrovascular Insufficiency

BACKGROUND: The M(5) muscarinic acetylcholine receptor is known to play a crucial role in mediating acetylcholine dependent dilation of cerebral blood vessels. Previously, we reported that male M(5) muscarinic acetylcholine knockout mice (M5R(-/-) mice) suffer from a constitutive constriction of cerebral arteries, reduced cerebral blood flow, dendritic atrophy, and short-term memory loss, without necrosis and/or inflammation in the brain. METHODOLOGY/PRINCIPAL FINDINGS: We employed the Magnetic Resonance Angiography to study the area of the basilar artery in male and female M5R(-/-) mice. Here we show that female M5R(-/-) mice did not show the reduction in vascular area observed in male M5R(-/-) mice. However, ovariectomized female M5R(-/-) mice displayed phenotypic changes similar to male M5R(-/-) mice, strongly suggesting that estrogen plays a key role in the observed gender differences. We found that 17beta-estradiol (E2) induced nitric oxide release and ERK activation in a conditional immortalized mouse brain cerebrovascular endothelial cell line. Agonists of ERalpha, ERbeta, and GPR30 promoted ERK activation in this cell line. Moreover, in vivo magnetic resonance imaging studies showed that the cross section of the basilar artery was restored to normal in male M5R(-/-) mice treated with E2. Treatment with E2 also improved the performance of male M5R(-/-) mice in a cognitive test and reduced the atrophy of neural dendrites in the cerebral cortex and hippocampus. M5R(-/-) mice also showed astrocyte swelling in cortex and hippocampus using the three-dimensional reconstruction of electron microscope images. This phenotype was reversed by E2 treatment, similar to the observed deficits in dendrite morphology and the number of synapses. CONCLUSIONS/SIGNIFICANCE: Our findings indicate that M5R(-/-) mice represent an excellent novel model system to study the beneficial effects of estrogen on cerebrovascular function and cognition. E2 may offer new therapeutic perspectives for the treatment of cerebrovascular insufficiency related memory dysfunction

Primjena i kompozicija individualiziranih zaštitnih elemenata linijske grafike u projektiranju novčanica

Proces stvaranja novčanica je dugotrajan i složen, što rezultira kompleksnim rješenjima koja predstavljaju pravo remek djelo grafike. Novčanice su prožete brojnim detaljima i prenose različite informacije koje se analiziraju u teorijskom dijelu rada. Prvotno se postavljaju kriteriji po kojima se izrađuje detaljna analiza velikog broja zaštitnih i konceptualnih elemenata na primjerima novčanica. Time je prikazan okvirni povijesni pregled razvoja novčanica i utjecaji kojima je bio izložen. Analizira se međuovisnost dizajna o sigurnosnim značajkama, te se ispituje razina informiranosti javnosti o zaštitama na novčanicama. Zaključuje se koje metode zaštite su najučinkovitije, te kako šira javnost najčešće provjerava autentičnost novčanica. U eksperimentalnom dijelu rada se na temelju donesenih zaključaka iz teorijskog dijela izrađuje prototip novčanice koja je u najvećoj mjeri prožeta individualiziranim PostScript programskim rješenjima elemenata linijske grafike (rozete, mikrotekst, zaštitne linije, brojevi apoena), a od ostalih zaštita modeliran je individualizirani raster transformacijom matematičkog izraza u PostScript programski kod. Sve ostale zaštite tipične za novčanice simulirane su alatima za rastersku i vektorsku grafiku. U radu se ispituje utjecaj kompozicije zaštitnih elemenata na prepoznavanje autentičnosti novčanica, te efikasnost samih individualiziranih programskih rješenja