Insights into the molecular mechanism of glucose metabolism regulation under stress in chicken skeletal muscle tissues

AbstractAs substantial progress has been achieved in modern poultry production with large-scale and intensive feeding and farming in recent years, stress becomes a vital factor affecting chicken growth, development, and production yield, especially the quality and quantity of skeletal muscle mass. The review was aimed to outline and understand the stress-related genetic regulatory mechanism, which significantly affects glucose metabolism regulation in chicken skeletal muscle tissues. Progress in current studies was summarized relevant to the molecular mechanism and regulatory pathways of glucose metabolism regulation under stress in chicken skeletal muscle tissues. Particularly, the elucidation of those concerned pathways promoted by insulin and insulin receptors would give key clues to the understanding of biological processes of stress response and glucose metabolism regulation under stress, as well as their later effects on chicken muscle development

Effects of in ovo feeding of chlorogenic acid on antioxidant capacity of postnatal broilers

In this study, chlorogenic acid (CGA) was injected into the amniotic cavity of chicken embryos to study the effects of in ovo feeding of CGA on the antioxidant capacity of postnatal broilers. On the 17th day of embryonic age, a total of 300 healthy broiler fertile eggs with similar weights were randomly subjected to five groups as follows; in ovo injection with 0.5 ml CGA at 4 mg/egg (4CGA) or 7 mg/egg (7CGA) or 10 mg/egg (10CGA), or sham-injection with saline (positive control, PC) or no injection (negative control, NC). Each group had six replicates of ten embryos. Six healthy chicks with similar body weights hatched from each replicate were selected and reared until heat stress treatment (35°C ± 1°C, 8 h/d) at 28–42 days of age. The results showed that there was no significant difference in the hatching rate between the groups (p > 0.05). After heat stress treatment, 4CGA group showed an improved intestinal morphology which was demonstrated by a higher villus height in the duodenum and a higher villus height/crypt depth ratio in the jejunum, compared with the NC group (p < 0.05). The antioxidant capacity of chickens was improved by in ovo feeding of CGA since 4CGA decreased the plasma content of malondialdehyde (MDA) (p < 0.05), whereas, it increased the superoxide dismutase (SOD), glutathione peroxidase (GPX), and catalase (CAT) activities compared with NC group (p < 0.05). Also, the MDA content of the different injection groups had a quadratic effect, with the 4CGA group having the lowest MDA content (Pquadratic < 0.05). In the duodenum, 4CGA injection significantly increased the mRNA expressions of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase 1 (H O -1), glutathione synthetase (GSS), and SOD1 compared to the NC and PC groups (p < 0.05). The mRNA expressions of glutathione reductase (GSR) and GPX7 were significantly increased in all CGA-treated groups compared with the PC group (p < 0.05), while the mRNA expression of CAT was significantly increased by 4CGA group than the NC group (p < 0.05). The mRNA expressions of epigenetic-related genes, ten eleven translocation 1 and 2 (Tet1 and Tet2), and DNA-methyltransferase 3 alpha (DNMT3A) in the duodenum of 4CGA injected group was significantly increased compared with the NC and PC groups (p < 0.05). The mRNA expressions of Nrf2, SOD1, and Tet2 showed a significant quadratic effects with the 4CGA group having the highest expression (Pquadratic < 0.05). In conclusion, in ovo feeding of CGA alleviated heat stress-induced intestinal oxidative damage. Injection with CGA of 4 mg/egg is considered most effective due to its actions in improving intestinal antioxidant capacity, especially in the duodenum. The antioxidant effects of in ovo CGA on postnatal heat-stressed broilers may be related to its regulation of epigenetic mechanisms. Thus, this study provides technical knowledge to support the in ovo feeding of CGA to alleviate oxidative stress in postnatal heat-stressed broilers

Catalytic selective oxidation of alcohols to carbonyl compounds by Ru-based catalysts

L'oxydation aérobie sélective des alcools en composés carbonylés est une transformation fondamentale et réalisable pour de nombreuses réactions biologiques et organiques fournissant des intermédiaires clés et des produits pharmaceutiques précieux. Les défis intrinsèques de réactivité et de sélectivité en chimie verte pour l'oxydation utilisant l'oxygène comme oxydant terminal limitent considérablement son application dans l'industrie. Les catalyseurs métalliques traditionnellement utilisés offrent une faible sélectivité due à la sur-oxydation des aldéhydes vers les acides correspondants. La combinaison récemment mise au point de piégeurs d'hydrogène organiques (e.g., DDQ, TEMPO) et d'agents de régénération inorganiques (Fe3+, NO) a été utilisée comme catalyseur pour une oxydation sélective des alcools en présence d'oxygène. Toutefois, la nature homogène du catalyseur et l'utilisation de produits chimiques toxiques et non respectueux de l'environnement nécessitent plus de développements de ce concept pour l'oxydation des alcools. Pour résoudre ces problèmes, nous proposons l'application d'un concept hétérogène de nano-électrocells inspiré de l'électrocatalyse. Les catalyseurs contiennent des nano-anodes et des nano-cathodes disposées en structure noyau-coquille à l'échelle nanométrique. L'alcool est oxydé sur les sites non métalliques quinones de la coquille, avec migration ultérieure de l'hydrogène vers le noyau métallique nanoparticules pour son oxydation en eau. Dans cette thèse, nous avons trouvé les matériaux "core" et "shell" appropriés, sur la base des espèces métalliques Ru et quinones non métalliques, respectivement, et nous les avons appliqués pour l'oxydation des alcools. Simultanément, nous proposons l'oxydation combinée à l'acétalisation à l'aide du catalyseur tandem Ru@MOF contenant des nanoparticules de Ru ultrafines (< 2 nm) dans la structure MOF.Selective aerobic oxidation of alcohols to carbonyl compounds is a fundamental and practicable transformation for many biological and organic reactions providing key intermediates and valuable pharmaceuticals. The intrinsic reactivity and selectivity challenges in green chemistry for oxidation using oxygen as terminal oxidant significantly restrict its application in industry. Traditionally used metallic catalysts provide low selectivity due to over-oxidation of aldehydes further to acids. The recently developed combination of organic hydrogen scavengers (DDQ, TEMPO) and inorganic regeneration agents (Fe3+, NO) have been used as a catalyst for mild selective oxidation of alcohols in the presence of oxygen. However, homogeneous nature of the catalyst and use of toxic and non-environmentally friendly chemicals require further development of this concept for oxidation of alcohols. To solve these problems, we propose application of heterogeneous nano-electrocell concept inspired from electrocatalysis. The catalysts contain nano-anode and nano-cathode sites arranged in core-shell structure at nano-scale level. The alcohol is oxidized over the non-metallic quinones shell sites, with subsequent migration of hydrogen to the metallic Ru nanoparticles as core for oxidation to water. In this thesis, we have found the appropriate “core” and “shell” materials, on the basic of metallic Ru and non-metallic quinones species, respectively, and applied it for oxidative dehydrogenation of alcohols and O2 reduction. Meanwhile we propose oxidation combined with acetalization using Ru@MOF tandem catalyst containing ultra-fine Ru nanoparticles (< 2 nm) in the MOF structure

Chicken embryo thermal manipulation alleviates postnatal heat stress-induced jejunal inflammation by inhibiting Transient Receptor Potential V4

Intestinal inflammation induced by heat stress is an important factor restricting the healthy growth of broilers. The aim of this study was to evaluate the effect of chicken embryo thermal manipulation (39.5 ℃ and 65 % RH for 3 h daily during 16–18 th embryonic age) on intestinal inflammation in broilers under postnatal heat stress and to investigate whether transient receptor potential V4 (TRPV4) plays a role in this process. Our results suggest that broilers with embryo thermal manipulation experience could delay the rising of rectal temperature during postnatal heat stress (P  0.05). Inhibition of TRPV4 reduced LPS-induced Ca2+ influx and restrained the activation of NF-κB signaling pathway and the expression of downstream pro-inflammatory cytokines (P < 0.05). The expression of DNA methyltransferase (DNMT) in the jejunum of broilers exposed to postnatal heat stress was increased by embryo thermal manipulation (P < 0.05). The DNA methylation level of TRPV4 promoter region was detected, and the results showed that embryo thermal manipulation increased the DNA methylation level of TRPV4 promoter region (P < 0.05). In conclusion, Chicken embryo thermal manipulation can alleviate jejunal inflammation in broilers under postnatal heat stress. This may be due to the decreased circulating LPS or the increased DNA methylation level in the promoter region of TRPV4, which inhibits TRPV4 expression, thereby reducing Ca2+ influx, and finally alleviating inflammation by affecting NF-κB signaling pathway. The work is an attempt to understand the mechanism involved in alleviation of adverse effects of heat stress during postnatal life through prenatal thermal manipulation and to reveal the important role of epigenetics

A high-caloric diet rich in soy oil alleviates oxidative damage of skeletal muscles induced by dexamethasone in chickens

Objective: Glucocorticoids (GCs) can induce oxidative damage in skeletal muscles. The purpose of this study was to demonstrate a high caloric (HC) diet rich in soy oil would change the oxidative stress induced by a GC. Methods: The effect of dexamethasone (DEX) and HC diet on oxidative stress in plasma, skeletal muscles (M. pectoralis major, PM; M. biceps femoris, BF), and mitochondria were determined. The biomarkers of oxidative damage and antioxidative enzyme activity were determined. The fatty acid profile of muscles and the activities of complex I and II in mitochondria were measured. Results: The results showed that DEX increased the concentrations of oxidative damage markers in plasma, muscles, and mitochondria. The activity of complex I was significantly suppressed by DEX. DEX-chickens had higher proportions of polyunsaturated fatty acids and lower proportions of monounsaturated fatty acids in the PM. A HC diet decreased the levels of oxidative damage biomarkers in plasma, muscles, and mitochondria. The interaction between DEX and diet suppressed the activities of complex I and II in HC-chickens. Discussion: Oxidative damage in skeletal muscles and mitochondria was the result of GC-induced suppression of the activity of mitochondrial complex I. A HC diet improved the antioxidative capacity and reduced the oxidative damage induced by the GC