The Effect of Adriamycin Exposure on the Notochord of Mouse Embryos

The notochord has important structural and signaling properties during vertebrate development with key roles in patterning surrounding tissues, including the foregut. The adriamycin mouse model is an established model of foregut anomalies where exposure of embryos in utero to the drug adriamycin leads to malformations including oesophageal atresia and tracheoesophageal fistula. In addition to foregut abnormalities, treatment also causes branching, displacement, and hypertrophy of the notochord. Here, we explore the hypothesis that the notochord may be a primary target of disruption leading to abnormal patterning of the foregut by examining notochord position and structure in early embryos following adriamycin exposure. Treated (n = 46) and control (n = 30) embryos were examined during the crucial period when the notochord normally delaminates away from the foregut endoderm (6–28 somite pairs). Transverse sections were derived from the anterior foregut and analyzed by confocal microscopy following immunodetection of extracellular matrix markers E‐cadherin and Laminin. In adriamycin‐treated embryos across all stages, the notochord was abnormally displaced ventrally with prolonged attachment to the foregut endoderm. While E‐cadherin was normally detected in the foregut endoderm with no expression in the notochord of control embryos, treated embryos up to 24 somites showed ectopic notochordal expression indicating a change in characteristics of the tissue; specifically an increase in intracellular adhesiveness, which may be instrumental in structural changes, affecting mechanical and signaling properties. This is consistent with disruption of the notochord leading to altered signaling to the foregut causing abnormal patterning and congenital foregut malformations.     

Increased in vivo inhibition of gene expression by combining RNA interference and U1 inhibition

Inhibition of gene expression can be achieved with RNA interference (RNAi) or U1 small nuclear RNA-snRNA-interference (U1i). U1i is based on U1 inhibitors (U1in), U1 snRNA molecules modified to inhibit polyadenylation of a target pre-mRNA. In culture, we have shown that the combination of RNAi and U1i results in stronger inhibition of reporter or endogenous genes than that obtained using either of the techniques alone. We have now used these techniques to inhibit gene expression in mice. We show that U1ins can induce strong inhibition of the expression of target genes in vivo. Furthermore, combining U1i and RNAi results in synergistic inhibitions also in mice. This is shown for the inhibition of hepatitis B virus (HBV) sequences or endogenous Notch1. Surprisingly, inhibition obtained by combining a U1in and a RNAi mediator is higher than that obtained by combining two U1ins or two RNAi mediators. Our results suggest that RNAi and U1i cooperate by unknown mechanisms to result in synergistic inhibitions. Analysis of toxicity and specificity indicates that expression of U1i inhibitors is safe. Therefore, we believe that the combination of RNAi and U1i will be a good option to block damaging endogenous genes, HBV and other infectious agents in vivo.     

Coumarin-trioxane hybrids: synthesis and evaluation as a new class of antimalarial scaffolds

First synthesis of novel coumarin-trioxane hybrids is reported. The synthesis was achieved via condensation of β-hydroxyhydroperoxides with coumarinic-aldehydes in presence of p-toluenesulfonic acid in good yields and the novel hybrids were evaluated for their antimalarial activity both in vitro and in vivo.     

Antidyslipidemic activity of polyprenol from Coccinia grandis in high-fat diet-fed hamster model

Ethanol extract of Coccinia grandis (L.) Voigt showed significant triglyceride (TG) and cholesterol-lowering effects in dyslipidemic hamster model. Ethanolic extract was fractionated into chloroform, n-butanol and water-soluble fractions and were evaluated. Activity was proved to be concentrated in chloroform-soluble fraction. Chloroform-soluble fraction containing active component was subjected to repeated column chromatography, furnished a polyprenol characterized as C₆₀-polyprenol (1) isolated for the first time from this plant. It significantly decreased serum TG by 42%, total cholesterol (TC) 25% and glycerol (Gly) 12%, accompanied HDL-C/TC ratio 26% in high-fat diet (HFD)-fed dyslipidemic hamsters at the dose of 50 mg/kg body weight. Results are comparable to standard drug fenofibrate at the dose of 108 mg/kg. Based on these investigations, it was concluded that the compound polyprenol (1) isolated from leaves of C. grandis possess marked antidyslipidemic activity.     

Negative correlation between cerebral inorganic phosphate and the volumetric niacin response in male patients with schizophrenia who have seriously and dangerously violently offended: a (31)P magnetic resonance spectroscopy study

The aim of the study was to examine the association of arachidonic acid-related signal transduction with cerebral metabolism in patients with schizophrenia who have violently and dangerously offended while psychotic. Cerebral 31-phosphorus magnetic resonance spectroscopy was carried out in 11 male patients with schizophrenia who had violently offended (homicide, attempted murder, or wounding with intent to cause grievous bodily harm) while psychotic. Spectra were obtained from 70 x 70 x 70 mm(3) voxels using an image-selected in vivo spectroscopy pulse sequence. Niacin flush testing results were quantified as the volumetric niacin response. There was a strong, and negative, correlation between the volumetric niacin response and the metabolite concentration of inorganic phosphate expressed as a ratio of the total 31-phosphorus signal (p<0.005). Our results suggest that patients with schizophrenia who have violently offended and have poor phospholipid-related signal transduction may have higher levels of cerebral energy metabolism.     

A 31-phosphorus neurospectroscopy study of omega-3 long-chain polyunsaturated fatty acid intervention with eicosapentaenoic acid and docosahexaenoic acid in patients with chronic refractory epilepsy

The aim of this study was to determine whether supplementation with the n-3 long-chain polyunsaturated fatty acids eicosapentaenoic acid and docosahexaenoic acid in patients with chronic refractory epilepsy is associated with beneficial changes in cerebral biochemistry. In a 3-month pilot randomized double-blind placebo-controlled study, three patients received eicosapentaenoic acid and docosahexaenoic acid daily and four received a placebo. 31-Phosphorus neurospectroscopy showed a decrease in phosphodiesters, an increase in gammaNTP and an increase in the broadband component in the active group over this period, while the opposite changes occurred in the placebo group. Therefore, in chronic refractory epilepsy, omega-3 supplementation may be associated with reduced membrane phospholipid breakdown in the brain, an improvement in brain energy metabolism, and an increased level of phospholipids in membranes and/or vesicle bilayers in cells in the brain. The unfavourable biochemical changes observed in the placebo group may be a feature of chronic intractable epilepsy.     

Commentary: ATG16L1 meets ATG9 in recycling endosomes: Additional roles for the plasma membrane and endocytosis in autophagosome biogenesis

Autophagosomes are formed by double-membraned structures, which engulf portions of cytoplasm. Autophagosomes ultimately fuse with lysosomes, where their contents are degraded. The origin of the autophagosome membrane may involve different sources, such as mitochondria, Golgi, endoplasmic reticulum, plasma membrane, and recycling endosomes. We recently observed that ATG9 localizes on the plasma membrane in clathrin-coated structures and is internalized following a classical endocytic pathway through early and then recycling endosomes. By contrast, ATG16L1 is also internalized by clathrin-mediated endocytosis but via different clathrin-coated pits, and appears to follow a different route to the recycling endosomes. The R-SNARE VAMP3 mediates the coalescence of the 2 different pools of vesicles (containing ATG16L1 or ATG9) in recycling endosomes. The heterotypic fusion between ATG16L1- and ATG9-containing vesicles strongly correlates with subsequent autophagosome formation. Thus, ATG9 and ATG16L1 both traffic from the plasma membrane to autophagic precursor structures and provide 2 routes from the plasma membrane to autophagosomes.