Defining an olfactory receptor function in airway smooth muscle cells

Pathways that control, or can be exploited to alter, the increase in airway smooth muscle (ASM) mass and cellular remodeling that occur in asthma are not well defined. Here we report the expression of odorant receptors (ORs) belonging to the superfamily of G-protein coupled receptors (GPCRs), as well as the canonical olfaction machinery (G olf and AC3) in the smooth muscle of human bronchi. In primary cultures of isolated human ASM, we identified mRNA expression for multiple ORs. Strikingly, OR51E2 was the most highly enriched OR transcript mapped to the human olfactome in lung-resident cells. In a heterologous expression system, OR51E2 trafficked readily to the cell surface and showed ligand selectivity and sensitivity to the short chain fatty acids (SCFAs) acetate and propionate. These endogenous metabolic byproducts of the gut microbiota slowed the rate of cytoskeletal remodeling, as well as the proliferation of human ASM cells. These cellular responses in vitro were found in ASM from non-asthmatics and asthmatics, and were absent in OR51E2-deleted primary human ASM. These results demonstrate a novel chemo-mechanical signaling network in the ASM and serve as a proof-of-concept that a specific receptor of the gut-lung axis can be targeted to treat airflow obstruction in asthma.open0

An overview of the recent developments on fructooligosaccharide production and applications

Over the past years, many researchers have suggested that deficiencies in the diet can lead to disease states and that some diseases can be avoided through an adequate intake of relevant dietary components. Recently, a great interest in dietary modulation of the human gut has been registered. Prebiotics, such as fructooligosaccharides (FOS), play a key role in the improvement of gut microbiota balance and in individual health. FOS are generally used as components of functional foods, are generally regarded as safe (generally recognized as safe status—from the Food and Drug Administration, USA), and worth about 150€ per kilogram. Due to their nutrition- and health-relevant properties, such as moderate sweetness, low carcinogenicity, low calorimetric value, and low glycemic index, FOS have been increasingly used by the food industry. Conventionally, FOS are produced through a two-stage process that requires an enzyme production and purification step in order to proceed with the chemical reaction itself. Several studies have been conducted on the production of FOS, aiming its optimization toward the development of more efficient production processes and their potential as food ingredients. The improvement of FOS yield and productivity can be achieved by the use of different fermentative methods and different microbial sources of FOS producing enzymes and the optimization of nutritional and culture parameter; therefore, this review focuses on the latest progresses in FOS research such as its production, functional properties, and market data.Agencia de Inovacao (AdI)-Project BIOLIFE reference PRIME 03/347. Ana Dominguez acknowledges Fundacao para a Ciencia e a Tecnologia, Portugal, for her PhD grant reference SFRH/BD/23083/2005

Frustrated behavior of Lewis/Brønsted pairs inside molecular cages

International audienceDifferent endohedrally functionalized cages were designed to investigate the effects of the size and shape of molecular cavities on the frustrated behavior of Lewis/Brønsted acid-base pairs and on catalytic activities. The shape of the inner space above the reactive center was found to strongly affect these properties. When an acidic azaphosphatrane is inserted in the smallest cage and associated with t-BuOK or − CD 2 CN bases, a frustrated Brønsted pair is obtained. In contrast, when encapsulated in the medium or large cage, the P-H + azaphosphatrane acid is easily deprotonated under the same conditions. The resulting two supramolecular Verkade's superbases lead to frustrated Lewis pair systems in the presence of TiCl 4. Furthermore, the larger cage displays better catalytic activity in the MBH reaction. Thus, a small change in the cage size, which only differs by one methylene group in the linkers, can influence the frustrated properties of the related systems, and a right balance between the frustrated behavior and cage flexibility has to be reached to obtain optimal systems for catalytic applications

Frustrated behavior of Lewis/Brønsted pairs inside molecular cages

Small changes in the cavity size and shape allow for modulating the level of frustration of endohedrally functionalized cages.</jats:p

Frustrated behavior of Lewis/Brønsted pairs inside molecular cages

International audienceDifferent endohedrally functionalized cages were designed to investigate the effects of the size and shape of molecular cavities on the frustrated behavior of Lewis/Brønsted acid-base pairs and on catalytic activities. The shape of the inner space above the reactive center was found to strongly affect these properties. When an acidic azaphosphatrane is inserted in the smallest cage and associated with t-BuOK or − CD 2 CN bases, a frustrated Brønsted pair is obtained. In contrast, when encapsulated in the medium or large cage, the P-H + azaphosphatrane acid is easily deprotonated under the same conditions. The resulting two supramolecular Verkade's superbases lead to frustrated Lewis pair systems in the presence of TiCl 4. Furthermore, the larger cage displays better catalytic activity in the MBH reaction. Thus, a small change in the cage size, which only differs by one methylene group in the linkers, can influence the frustrated properties of the related systems, and a right balance between the frustrated behavior and cage flexibility has to be reached to obtain optimal systems for catalytic applications