Molecular and cellular substrates for the Friedreich Ataxia. significance of contactin expression and of antioxidant administration

In this study, the neural phenotype is explored in rodent models of the spinocerebellar disorder known as the Friedreich Ataxia (FA), which results from mutations within the gene encoding the Frataxin mitochondrial protein. For this, the M12 line, bearing a targeted mutation, which disrupts the Frataxin gene exon 4 was used, together with the M02 line, which, in addition, is hemizygous for the human Frataxin gene mutation (Pook transgene), implying the occurrence of 82–190 GAA repeats within its first intron. The mutant mice phenotype was compared to the one of wild type littermates in regions undergoing differential profiles of neurogenesis, including the cerebellar cortex and the spinal cord by using neuronal (β-tubulin) and glial (Glial Fibrillary Acidic Protein) markers as well as the Contactin 1 axonal glycoprotein, involved in neurite growth control. Morphological/morphometric analyses revealed that while in Frataxin mutant mice the neuronal phenotype was significantly counteracted, a glial upregulation occurred at the same time. Furthermore, Contactin 1 downregulation suggested that changes in the underlying gene contributed to the disorder pathogenesis. Therefore, the FA phenotype implies an alteration of the developmental profile of neuronal and glial precursors. Finally, epigallocatechin gallate polyphenol administration counteracted the disorder, indicating protective effects of antioxidant administration

Protective effects of eicosapentaenoic acid plus hydroxytyrosol supplementation against white adipose tissue abnormalities in mice fed a high-fat diet

Objective: Obesity induced by high-fat diet (HFD) elicits white adipose tissue dysfunction. In this study, we have hypothesized that the metabolic modulator eicosapentaenoic acid (EPA) combined with the antioxidant hydroxytyrosol (HT) attenuates HFD-induced white adipose tissue (WAT) alterations. Methods: C57BL/6J mice were administered with a HFD (60% fat, 20% protein, 20% carbohydrates) or control diet (CD; 10% fat, 20% protein, 70% carbohydrates), with or without EPA (50 mg/kg/day), HT (5 mg/kg/day), or both for 12 weeks. Determinations in WAT include morphological parameters, EPA and docosahexaenoic acid content in phospholipids (gas chromatography), lipogenesis, oxidative stress (OS) and inflammation markers, and gene expression and activities of transcription factors, such as sterol regulatory element-binding protein-1c (SREBP-1c), peroxisome proliferator-activated receptor-gamma (PPAR-γ), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) (p65 subunit) and nuclear factor erythroid 2-related factor 2 (Nrf2) (quantitative polymerase chain reaction and enzyme linked immunosorbent assay). Results: HFD led to WAT hypertrophy in relation to PPAR-γ downregulation. WAT metabolic dysfunction was characterized by upregulation of lipogenic SREBP-1c system, mitochondrial energy metabolism depression, loss of the antioxidant Nrf2 signaling with OS enhancement, n-3 long-chain polyunsaturated fatty acids depletion and activation of the pro-inflammatory NF-κB system. EPA and HT co-supplementation diminished HFD-dependent effects additively, reaching values close or similar to controls. Conclusion: Data presented strengthen the importance of combined protocols such as EPA plus HT to attenuate metabolic-inflammatory states triggered by obesity

Multiplicity of Positive Solutions for an Obstacle Problem in R

In this paper we establish the existence of two positive solutions for the obstacle problem \displaystyle \int_{\Re}\left[u'(v-u)'+(1+\lambda V(x))u(v-u)\right] \geq \displaystyle \int_{\Re} f(u)(v-u), \forall v\in \Ka where $f$ is a continuous function verifying some technical conditions and \Ka is the convex set given by \Ka =\left\{v\in H^{1}(\Re); v \geq \varphi \right\}, with $\varphi \in H^{1}(\Re)$ having nontrivial positive part with compact support in $\Re$. \vspace{0.2cm} \noindent \emph{2000 Mathematics Subject Classification} : 34B18, 35A15, 46E39. \noindent \emph{Key words}: Obstacle problem, Variational methods, Positive solutions.Comment: To appear in Progress in Nonlinear Differential Equations and their Application

Epiboxidine and Novel Related Analogues : a Convenient Synthetic Approach and Estimation of Their Affinity at Neuronal Nicotinic Acetylcholine Receptor Subtypes

Racemic exo-epiboxidine 3, endo-epiboxidine 6, and the two unsaturated epiboxidine-related derivatives 7 and 8 were efficiently prepared taking advantage of a palladium-catalyzed Stille coupling as the key step in the reaction sequence. The target compounds were assayed for their binding affinity at neuronal alpha 4 beta 2 and alpha 7 nicotinic acetylcholine receptors. Epiboxidine 3 behaved as a high affinity alpha 4 beta 2 ligand (K-i = 0.4 nM) and, interestingly, evidenced a relevant affinity also for the alpha 7 subtype (K-i = 6 nM). Derivative 7, the closest analogue of 3 in this group, bound with lower affinity at both receptor subtypes (K-i = 50 nM for alpha 4 beta 2 and K-i = 1.6 mu M for alpha 7) evidenced a gain in the alpha 4 beta 2 versus 00 selectivity when compared with the model compound

Red wine and components flavonoids inhibit UGT2B17 in vitro

Background The metabolism and excretion of the anabolic steroid testosterone occurs by glucuronidation to the conjugate testosterone glucuronide which is then excreted in urine. Alterations in UGT glucuronidation enzyme activity could alter the rate of testosterone excretion and thus its bioavailability. The aim of this study is to investigate if red wine, a common dietary substance, has an inhibitory effect on UGT2B17. Methods Testosterone glucuronidation was assayed using human UGT2B17 supersomes with quantification of unglucuronidated testosterone over time using HPLC with DAD detection. The selected red wine was analysed using HPLC and the inhibitory effects of the wine and phenolic components were tested independently in a screening assay. Further analyses were conducted for the strongest inhibitors at physiologically relevant concentrations. Control experiments were conducted to determine the effects of the ethanol on UGT2B17. Results Over the concentration range of 2 to 8% the red wine sample inhibited the glucuronidation of testosterone by up to 70% over 2 hours. The ethanol content had no significant effect. Three red wine phenolics, identified by HLPC analyses, also inhibited the enzyme by varying amounts in the order of quercetin (72%), caffeic acid (22%) and gallic acid (9%); using a ratio of phenolic:testosterone of 1:2.5. In contrast p-coumaric acid and chlorogenic acid had no effect on the UGT2B17. The most active phenolic was selected for a detailed study at physiologically relevant concentrations, and quercetin maintained inhibitory activity of 20% at 2 M despite a ten-fold excess of testosterone. Conclusion This study reports that in an in vitro supersome-based assay, the key steroid-metabolising enzyme UGT2B17 is inhibited by a number of phenolic dietary substances and therefore may reduce the rate of testosterone glucuronidation in vivo. These results highlight the potential interactions of a number of common dietary compounds on testosterone metabolism. Considering the variety of foodstuffs that contain flavonoids, it is feasible that diet can elevate levels of circulating testosterone through reduction in urinary excretion. These results warrant further investigation and extension to a human trial to delineate the healt

Microbial shifts in the aging mouse gut

YesBackground: The changes that occur in the microbiome of aging individuals are unclear, especially in light of the imperfect correlation of frailty with age. Studies in older human subjects have reported subtle effects, but these results may be confounded by other variables that often change with age such as diet and place of residence. To test these associations in a more controlled model system, we examined the relationship between age, frailty, and the gut microbiome of female C57BL/6 J mice. Results: The frailty index, which is based on the evaluation of 31 clinical signs of deterioration in mice, showed a near-perfect correlation with age. We observed a statistically significant relationship between age and the taxonomic composition of the corresponding microbiome. Consistent with previous human studies, the Rikenellaceae family, which includes the Alistipes genus, was the most significantly overrepresented taxon within middle-aged and older mice. The functional profile of the mouse gut microbiome also varied with host age and frailty. Bacterial-encoded functions that were underrepresented in older mice included cobalamin (B12) and biotin (B7) biosynthesis, and bacterial SOS genes associated with DNA repair. Conversely, creatine degradation, associated with muscle wasting, was overrepresented within the gut microbiomes of the older mice, as were bacterial-encoded β-glucuronidases, which can influence drug-induced epithelial cell toxicity. Older mice also showed an overabundance of monosaccharide utilization genes relative to di-, oligo-, and polysaccharide utilization genes, which may have a substantial impact on gut homeostasis. Conclusion: We have identified taxonomic and functional patterns that correlate with age and frailty in the mouse microbiome. Differences in functions related to host nutrition and drug pharmacology vary in an age-dependent manner, suggesting that the availability and timing of essential functions may differ significantly with age and frailty. Future work with larger cohorts of mice will aim to separate the effects of age and frailty, and other factors.This work was supported by the Canadian Institutes of Health Research (CIHR) through an Emerging Team Grant to RGB, CIHR Operating Grants to Langille et al. Microbiome 2014, 2:50 Page 10 of 12 http://www.microbiomejournal.com/content/2/1/50 SEH (MOP 126018) and RAR (MOP 93718), and a CIHR Fellowship to MGIL. Infrastructure was supported by the Canada Foundation for Innovation through a grant to RGB. RGB also acknowledges the support of the Canada Research Chairs program

Design, synthesis and pharmacology of novel ligands targeting neuronal nicotinic acetylcholine receptor subtypes

Neuronal nicotinic acetylcholine receptors (nAChRs) make up a family of pentameric ligand-gated ion channels which are formed by combinations of alpha and beta subunits or exist as homopentamers, in the cases of \u3b1-7, \u3b1-8, and \u3b1-9 receptors, which are inhibited by \u3b1-bungarotoxin. To date, nine \u3b1 (\u3b1-2-\u3b1-10) and three \u3b2(\u3b22-\u3b24) isoforms have been characterized, though only a relatively small subset of combinations generates functionally and physiologically relevant channels. Nicotinic receptors are widely distributed in the brain, where they primarily modulate the release of other neurotransmitters and, to a lesser extent, mediate synaptic transmission. Neuronal nAChRs are involved in various processes such as cognition, learning and memory, cerebral blood flow and metabolism, as well as an array of pathological conditions such as Alzheimer\u2019s and Parkinson\u2019s diseases, mild cognitive impairment (MCI), schizophrenia, epilepsy, Tourette\u2019s syndrome, anxiety, depression, attention-deficit hyperactivity disorder (ADHD), and nicotine addiction. The heteromeric \u3b14\u3b22 and the homomeric \u3b17 nAChR subtypes represent the most relevant biological targets in view of potential therapeutic applications for the above cited pathologies. In this study, the group of novel stereoisomeric \u3942-isoxazolines 1a-1f and 2a-f, structurally related to the \u3b14\u3b22 selective nicotinic agonist ABT-418, has been prepared and tested at neuronal \u3b14\u3b22 and \u3b17 nAChR subtypes. Moreover, (-)-Cytisine 3, a natural selective \u3b14\u3b22 ligand, was taken as model compound to synthesize the group of 4-substituted derivatives 4-8.The two series of derivates were synthesized by taking advantage of a 1,3-dipolar or a 1,6-intramolecular cycloaddition processes.On the other hand, as an extension of a previous research project, we prepared a group of novel derivatives characterized by a spirocylic junction between the quinuclidine ring and the \u3942-isoxazoline (8a-g and 9a-g) or the isoxazolidin-3-one (10a-b) moieties. Some of the compounds under study behaved as potent and selective \u3b17 nAChR agonists/partial agonists and were further investigated in in vitro and in vivo tests