Recent Insights into the Pathogenesis of Acute Porphyria Attacks and Increasing Hepatic PBGD as an Etiological Treatment

Rare diseases, especially monogenic diseases, which usually affect a single target protein, have attracted growing interest in drug research by encouraging pharmaceutical companies to design and develop therapeutic products to be tested in the clinical arena. Acute intermittent porphyria (AIP) is one of these rare diseases. AIP is characterized by haploinsufficiency in the third enzyme of the heme biosynthesis pathway. Identification of the liver as the target organ and a detailed molecular characterization have enabled the development and approval of several therapies to manage this disease, such as glucose infusions, heme replenishment, and, more recently, an siRNA strategy that aims to down-regulate the key limiting enzyme of heme synthesis. Given the involvement of hepatic hemoproteins in essential metabolic functions, important questions regarding energy supply, antioxidant and detoxifying responses, and glucose homeostasis remain to be elucidated. This review reports recent insights into the pathogenesis of acute attacks and provides an update on emerging treatments aimed at increasing the activity of the deficient enzyme in the liver and restoring the physiological regulation of the pathway. While further studies are needed to optimize gene therapy vectors or large-scale production of liver-targeted PBGD proteins, effective protection of PBGD mRNA against the acute attacks has already been successfully confirmed in mice and large animals, and mRNA transfer technology is being tested in several clinical trials for metabolic diseases

Expression of alternansucrase in potato plants

Alternan, which consists of alternating α-(1→3)/α-(1→6)-linked glucosyl residues, was produced in potato tubers by expressing a mature alternansucrase (Asr) gene from Leuconostoc mesenteroides NRRL B-1355 in potato. Detection of alternan was performed by enzyme-linked immunosorbent assay in tuber juices, revealing a concentration between 0.3 and 1.2 mg g-1 fresh wt. The Asr transcript levels correlated well with alternan accumulation in tuber juices. It appeared that the expression of sucrose-regulated starch-synthesizing genes (ADP-glucose pyrophosphorylase subunit S and granule-bound starch synthase I) was down-regulated. Despite this, the physico-chemical properties of the transgenic starches were unaltered. These results are compared to those obtained with other transgenic potato plants producing mutan [α-(1→3)-linked glucosyl residues] and dextran [α-(1→6)-linked glucosyl residues]

Analyse des signaux pour un dispositif de mesure et de stimulation du système nerveux central

- Un des enjeux actuels en Neurosciences est de pouvoir enregistrer simultanément les activités d'un grand nombre de cellules au sein de grands réseaux de neurones, et de pouvoir stimuler de manière dynamique ces réseaux afin d'en contrôler les activités. Le but du projet Neurocom est de réaliser un système multiélectrode haute densité intégré sur silicium, permettant d'enregistrer et de stimuler de grands réseaux de neurones in vitro. Ce dispositif sera constitué d'une microstructure d'électrodes stérilisable hybridée sur un circuit analogique intégré (préamplification, filtrage, multiplexage, stimulation), lui-même interfacé via une carte numérique de commande et acquisition reliée à un PC. Afin de pouvoir mieux appréhender les phénomènes bioélectriques et électrochimiques à l'interface capteur et donc mieux spécifier le cahier des charges et l'architecture du système, la maquette de test NEUROCOM1 a été conçue en électronique discrète et est actuellement utilisée pour conduire différents tests

ON THE WAY TO LIGANDLESS PD-CATALYTIC SYSTEM FOR SITE-SELECTIVE INDOLE ARYLATION ON WATER

International @ BIOVERT+LDJInternational audienceNon

Innovative one-pot heterogeneous Pd-catalysed synthesis of stylbenes, bibenzyls and bis(bibenzyls).

internationa

The future of host cell protein (HCP) identification during process development and manufacturing linked to a risk-based management for their control.

The use of biological systems to synthesize complex therapeutic products has been a remarkable success. However, during product development, great attention must be devoted to defining acceptable levels of impurities that derive from that biological system, heading this list are host cell proteins (HCPs). Recent advances in proteomic analytics have shown how diverse this class of impurities is; as such knowledge and capability grows inevitable questions have arisen about how thorough current approaches to measuring HCPs are. The fundamental issue is how to adequately measure (and in turn monitor and control) such a large number of protein species (potentially thousands of components) to ensure safe and efficacious products. A rather elegant solution is to use an immunoassay (enzyme-linked immunosorbent assay [ELISA]) based on polyclonal antibodies raised to the host cell (biological system) used to synthesize a particular therapeutic product. However, the measurement is entirely dependent on the antibody serum used, which dictates the sensitivity of the assay and the degree of coverage of the HCP spectrum. It provides one summed analog value for HCP amount; a positive if all HCP components can be considered equal, a negative in the more likely event one associates greater risk with certain components of the HCP proteome. In a thorough risk-based approach, one would wish to be able to account for this. These issues have led to the investigation of orthogonal analytical methods; most prominently mass spectrometry. These techniques can potentially both identify and quantify HCPs. The ability to measure and monitor thousands of proteins proportionally increases the amount of data acquired. Significant benefits exist if the information can be used to determine critical HCPs and thereby create an improved basis for risk management. We describe a nascent approach to risk assessment of HCPs based upon such data, drawing attention to timeliness in relation to biosimilar initiatives. The development of such an approach requires databases based on cumulative knowledge of multiple risk factors that would require national and international regulators, standards authorities (e.g., NIST and NIBSC), industry and academia to all be involved in shaping what is the best approach to the adoption of the latest bioanalytical technology to this area, which is vital to delivering safe efficacious biological medicines of all types

Heterogeneously Pd/C catalysed procedure for the vinylation of aryl bromides

Joucla, Lionel Cusati, Giuseppe Pinel, Catherine Djakovitch, LaurentHeterogeneous Pd/C catalyst was applied to the Suzuki-Miyaura vinylation of various aryl and heteroaryl halides under aerobic and mild reaction conditions [1.0 mmol aryl halide, 1.5 mmol potassium vinyltrifluoroborate, 3.0 mmol K3PO4 center dot H2O, 0.1 mol% Pd/C-(EVO), 1 mL NMP, 100 degrees C, 24 h]. Useful isolated yields (57-73%) were achieved. In some cases, the catalytic system should be tuned to face the reactivity of the aryl halides: while 0.1 mol% Pd/C is sufficient for almost all aryl bromides, 1.0 mol% Pd/C was used for free phenols. The heterogeneous catalyst was proved to be stable upon several catalytic cycles: however, the results showed that this was dependent on addition of the base. Hot-filtration experiment indicates that the activity was mainly due to leached Pd-species, indicating that the Pd/C catalyst acts as a palladium reservoir. (c) 2009 Elsevier B.V. All rights reserved

Efficient heterogeneous vinylation of aryl halides using potassium vinyltrifluoroborate

International audienceAn efficient heterogeneously palladium catalysed procedure for the vinylation of aryl iodides and bromides is reported. Using common reaction conditions (Pd/C 2 mol %, AcONa3H2O, NMP or NMP/H2O), good to complete conversions (40–100%) with high selectivities (79–100%) towards the expected vinylaromatic were achieved

One-pot palladium-catalysed synthesis of stilbene derivatives

internationa

One-Pot Suzuki/Heck Sequence for the Synthesis of (E)-Stilbenes Featuring a Recyclable Silica-Supported Palladium Catalyst via a Multi-Component Reaction in 1,3-Propanediol

Joucla, Lionel Cusati, Giuseppe Pinel, Catherine Djakovitch, LaurentThe synthesis of (E)-stilbenes was performed following a one-pot Suzuki/Heck sequence through the use of potassium vinyltrifluoroborate. The combination of heterogeneous palladium/silica (Pd/SiO2) catalyst with potassium phosphate monohydrate (K3PO4H2O) as base resulted in useful to good isolated yields regardless of the ortho-, meta- or para-substitution of the aryl halides employed. In a sustainable approach. we found that bio-sourced 1,3-propanediol could advantageously replace N-methyl-pyrrolidone (NMP) as similar yields were obtained Moreover, the reactivity gap between aryl iodides and bromides resulting from the use of 1,3-propanediol allowed an efficient multi-component approach toward the synthesis of (E)-stilbenes. Furthermore. this heterogeneous catalyst was found to he extremely robust despite the use of aerobic conditions and was successfully re-used over several cycles