Background: Resveratrol, a plant phenol, affords protection against inflammation and oxidative stress. The objective of this study was to investigate the effects of dietary resveratrol supplementation during pregnancy...Background: Resveratrol, a plant phenol, affords protection against inflammation and oxidative stress. The objective of this study was to investigate the effects of dietary resveratrol supplementation during pregnancy and lactation on the antioxidant status of sows and piglets and on antioxidant gene expression and pathway in placenta.Methods: Forty sows were allotted to 2 dietary treatments 20 d after breeding. Sows were fed a control diet and a control diet with 300 mg/kg resveratrol. Oxidative stress biomarkers and antioxidant enzymes were measured in the placenta, milk, and plasma of sows and piglets. Antioxidant gene expression and protein expression of Kelch-like ECH-associated protein 1-Nuclear factor E2-related factor 2(Keap1-Nrf2), nuclear factor kappa B-p65(NFκB-p65) and sirtuin1(Sirt1) were quantified in the placenta.Results: Dietary resveratrol increased the litter and piglets weaning weights. Antioxidant status in the milk, placenta and plasma of sows and piglets was partially improved by dietary resveratrol. In placenta, Nrf2 protein expression was increased and Keap1 protein expression was decreased by dietary resveratrol. The m RNA expression of antioxidant genes including catalase(CAT), glutathione peroxidase 1(GPX1), GPX4, superoxide dismutase 1(SOD1)and heme oxygenase 1(HO1), and phase 2 detoxification genes, including glutamate-cysteine ligase modifier(GCLM), microsomal glutathione S-transferase 1(MGST1) and UDP glucuronosyltransferase family 1 member A1(UGT1 A1), was increased by dietary resveratrol. Dietary resveratrol also increased Sirt1 and phosphorylated NFκB-p65 protein expression in the placenta. We failed to observe any influences of dietary resveratrol on pro-inflammatory cytokine levels, including those of interleukin 1β(IL-1β), IL-6, IL-8 and tumor necrosis factor α(TNF-α). However, we observed that the m RNA expression of IL-8 in placenta was reduced by maternal resveratrol. In addition, dietary resveratrol showed interactive effects with day of lactation on activities of SOD and CAT and levels of malonaldehyde(MDA) and hydrogen peroxide(H2 O2) in milk.Conclusions: Dietary resveratrol supplementation during pregnancy and lactation improves the antioxidant status of sows and piglets, which is beneficial to the reproductive performance of sows. Dietary resveratrol regulates placental antioxidant gene expression by the Keap1-Nrf2 pathway and Sirt1 in placenta.展开更多
This work investigates the potential of combining hardness gradient with surface texture （an example of bionic coupling） to improve anti-wear properties. The bionic coupling of hardness gradient and Hexagonal Textu...This work investigates the potential of combining hardness gradient with surface texture （an example of bionic coupling） to improve anti-wear properties. The bionic coupling of hardness gradient and Hexagonal Texture （HT） was achieved by laser heat treatment on steel specimens with pre-engraved hexagonal surface texture. The successful establishment of decreasing hardness from surface to internal bulk was verified by hardness measurements along the depth of cross-sectioned specimens and corre- lated with the observations from metallurgical microscopy. The tribological performance of bionic coupling specimens （HT-L） was examined under dry contact condition, together with respective control specimens of individual bionic features, e.g. HT-H （of similar surface hardness generated by conventional heat treatment but without hardness gradient） and SS-L （of smooth surface treated by the same laser processing as for HT-L）. It is found that HT-L not only exhibits lower friction coefficient and less friction fluctuation than HT-H and SS-L, but also demonstrates a 〉50% reduction of wear loss compared to HT-H and SS-L （0.0343 g for HT-L vs. 0.0723 g for HT-H, P〈0.001; 0.0343 g for HT-L vs. 0.0817 g for SS-L, P〈0.001）. Corroboratively, observations with scanning electron microscopy revealed a relatively smooth surface for worn HT-L specimen, contrasting with the rugged and grooved surfaces of worn HT-H and SS-L specimens. These results indicate that the bionic coupling of hardness gradient to hexagonal texture can indeed improve anti-wear properties, affording a new strategy to wear and friction manage- ment.展开更多
基金supported by the National Key Research and Development Plan of China(2016YFD0501207)the China Agriculture Research System(CARS-36)the National Basic Research Program(2012CB124703)
文摘Background: Resveratrol, a plant phenol, affords protection against inflammation and oxidative stress. The objective of this study was to investigate the effects of dietary resveratrol supplementation during pregnancy and lactation on the antioxidant status of sows and piglets and on antioxidant gene expression and pathway in placenta.Methods: Forty sows were allotted to 2 dietary treatments 20 d after breeding. Sows were fed a control diet and a control diet with 300 mg/kg resveratrol. Oxidative stress biomarkers and antioxidant enzymes were measured in the placenta, milk, and plasma of sows and piglets. Antioxidant gene expression and protein expression of Kelch-like ECH-associated protein 1-Nuclear factor E2-related factor 2(Keap1-Nrf2), nuclear factor kappa B-p65(NFκB-p65) and sirtuin1(Sirt1) were quantified in the placenta.Results: Dietary resveratrol increased the litter and piglets weaning weights. Antioxidant status in the milk, placenta and plasma of sows and piglets was partially improved by dietary resveratrol. In placenta, Nrf2 protein expression was increased and Keap1 protein expression was decreased by dietary resveratrol. The m RNA expression of antioxidant genes including catalase(CAT), glutathione peroxidase 1(GPX1), GPX4, superoxide dismutase 1(SOD1)and heme oxygenase 1(HO1), and phase 2 detoxification genes, including glutamate-cysteine ligase modifier(GCLM), microsomal glutathione S-transferase 1(MGST1) and UDP glucuronosyltransferase family 1 member A1(UGT1 A1), was increased by dietary resveratrol. Dietary resveratrol also increased Sirt1 and phosphorylated NFκB-p65 protein expression in the placenta. We failed to observe any influences of dietary resveratrol on pro-inflammatory cytokine levels, including those of interleukin 1β(IL-1β), IL-6, IL-8 and tumor necrosis factor α(TNF-α). However, we observed that the m RNA expression of IL-8 in placenta was reduced by maternal resveratrol. In addition, dietary resveratrol showed interactive effects with day of lactation on activities of SOD and CAT and levels of malonaldehyde(MDA) and hydrogen peroxide(H2 O2) in milk.Conclusions: Dietary resveratrol supplementation during pregnancy and lactation improves the antioxidant status of sows and piglets, which is beneficial to the reproductive performance of sows. Dietary resveratrol regulates placental antioxidant gene expression by the Keap1-Nrf2 pathway and Sirt1 in placenta.
基金This work was supported by National Natural Science Foundation of China （51375204）, Jilin Provin- cial Science ＆ Technology Department （20140101056JC）, and Project ＂985＂ on Engineering Bionics of Jilin University. We thank Prof. Yan Shi and Dr. Jia Liu from Changchun University of Science and Technology for their help on laser heat treatment.
文摘This work investigates the potential of combining hardness gradient with surface texture （an example of bionic coupling） to improve anti-wear properties. The bionic coupling of hardness gradient and Hexagonal Texture （HT） was achieved by laser heat treatment on steel specimens with pre-engraved hexagonal surface texture. The successful establishment of decreasing hardness from surface to internal bulk was verified by hardness measurements along the depth of cross-sectioned specimens and corre- lated with the observations from metallurgical microscopy. The tribological performance of bionic coupling specimens （HT-L） was examined under dry contact condition, together with respective control specimens of individual bionic features, e.g. HT-H （of similar surface hardness generated by conventional heat treatment but without hardness gradient） and SS-L （of smooth surface treated by the same laser processing as for HT-L）. It is found that HT-L not only exhibits lower friction coefficient and less friction fluctuation than HT-H and SS-L, but also demonstrates a 〉50% reduction of wear loss compared to HT-H and SS-L （0.0343 g for HT-L vs. 0.0723 g for HT-H, P〈0.001; 0.0343 g for HT-L vs. 0.0817 g for SS-L, P〈0.001）. Corroboratively, observations with scanning electron microscopy revealed a relatively smooth surface for worn HT-L specimen, contrasting with the rugged and grooved surfaces of worn HT-H and SS-L specimens. These results indicate that the bionic coupling of hardness gradient to hexagonal texture can indeed improve anti-wear properties, affording a new strategy to wear and friction manage- ment.
