Maternal stress during pregnancy is prevailing worldwide, which exposes fetuses to intrauterine hyper glucocorticoids(GC), programming offspring to obesity and metabolic diseases. Despite the importance of brown adipo...Maternal stress during pregnancy is prevailing worldwide, which exposes fetuses to intrauterine hyper glucocorticoids(GC), programming offspring to obesity and metabolic diseases. Despite the importance of brown adipose tissue(BAT) in maintaining long-term metabolic health, impacts of prenatal hyper GC on postnatal BAT thermogenesis and underlying regulations remain poorly defined. Pregnant mice were administrated with synthetic GC dexamethasone(DEX) at levels comparable to fetal GC exposure of stressed mothers. Prenatal GC exposure dose-dependently reduced BAT thermogenic activity, contributing to lower body temperature and higher mortality of neonates;such difference was abolished under thermoneutrality, underscoring BAT deficiency was the major contributor to adverse changes in postnatal thermogenesis due to excessive GC. Prenatal GC exposure highly activated Redd1 expression and reduced Ppargc1 a transcription from the alternative promoter(Ppargc1 a-AP) in neonatal BAT. During brown adipocyte differentiation, ectopic Redd1 expression reduced Ppargc1 a-AP expression and mitochondrial biogenesis;and the inhibitory effects of GC on mitochondrial biogenesis and Ppargc1 a-AP expression were blocked by Redd1 ablation. Redd1 reduced protein kinase A phosphorylation and suppressed cyclic adenosine monophosphate(c AMP)-responsive element-binding protein(CREB) binding to the c AMP regulatory element(CRE) in Ppargc1 a-AP promoter, leading to Ppargc1 a-AP inactivation. In summary, excessive maternal GC exposure during pregnancy dysregulates Redd1-Ppargc1 a-AP axis, which impairs fetal BAT development, hampering postnatal thermogenic adaptation and metabolic health of offspring.展开更多
该文旨在研究初始脂肪含量、贮存温度对超高温灭菌(ultra high temperature sterilized,UHT)牛奶贮存期间的品质变化及货架期影响规律。对23、30、37℃无光照贮存过程中不同初始脂肪含量UHT纯牛奶的色泽、蛋白水解度、羰基含量进行分析...该文旨在研究初始脂肪含量、贮存温度对超高温灭菌(ultra high temperature sterilized,UHT)牛奶贮存期间的品质变化及货架期影响规律。对23、30、37℃无光照贮存过程中不同初始脂肪含量UHT纯牛奶的色泽、蛋白水解度、羰基含量进行分析,比较各指标对感官评分的Pearson系数,应用Arrhenius方程等建立货架期预测模型。随着贮存时间的延长、贮存温度的升高,样品的褐变指数、蛋白水解度、羰基含量均随之提高,而感官评分值降低;将感官评分和其他指标进行Pearson相关性分析筛选出褐变指数作为反映其品质变化的关键指标,建立基于初始脂肪含量和贮存温度影响的货架期预测模型,模型预测值与实际货架期验证比较,相对误差小于10%。所建预测模型可有效预测无光照下不同初始脂肪含量UHT牛奶货架期。展开更多
基金This work was supported by the National Institute of Health(NIH R01-HD067449)。
文摘Maternal stress during pregnancy is prevailing worldwide, which exposes fetuses to intrauterine hyper glucocorticoids(GC), programming offspring to obesity and metabolic diseases. Despite the importance of brown adipose tissue(BAT) in maintaining long-term metabolic health, impacts of prenatal hyper GC on postnatal BAT thermogenesis and underlying regulations remain poorly defined. Pregnant mice were administrated with synthetic GC dexamethasone(DEX) at levels comparable to fetal GC exposure of stressed mothers. Prenatal GC exposure dose-dependently reduced BAT thermogenic activity, contributing to lower body temperature and higher mortality of neonates;such difference was abolished under thermoneutrality, underscoring BAT deficiency was the major contributor to adverse changes in postnatal thermogenesis due to excessive GC. Prenatal GC exposure highly activated Redd1 expression and reduced Ppargc1 a transcription from the alternative promoter(Ppargc1 a-AP) in neonatal BAT. During brown adipocyte differentiation, ectopic Redd1 expression reduced Ppargc1 a-AP expression and mitochondrial biogenesis;and the inhibitory effects of GC on mitochondrial biogenesis and Ppargc1 a-AP expression were blocked by Redd1 ablation. Redd1 reduced protein kinase A phosphorylation and suppressed cyclic adenosine monophosphate(c AMP)-responsive element-binding protein(CREB) binding to the c AMP regulatory element(CRE) in Ppargc1 a-AP promoter, leading to Ppargc1 a-AP inactivation. In summary, excessive maternal GC exposure during pregnancy dysregulates Redd1-Ppargc1 a-AP axis, which impairs fetal BAT development, hampering postnatal thermogenic adaptation and metabolic health of offspring.
文摘该文旨在研究初始脂肪含量、贮存温度对超高温灭菌(ultra high temperature sterilized,UHT)牛奶贮存期间的品质变化及货架期影响规律。对23、30、37℃无光照贮存过程中不同初始脂肪含量UHT纯牛奶的色泽、蛋白水解度、羰基含量进行分析,比较各指标对感官评分的Pearson系数,应用Arrhenius方程等建立货架期预测模型。随着贮存时间的延长、贮存温度的升高,样品的褐变指数、蛋白水解度、羰基含量均随之提高,而感官评分值降低;将感官评分和其他指标进行Pearson相关性分析筛选出褐变指数作为反映其品质变化的关键指标,建立基于初始脂肪含量和贮存温度影响的货架期预测模型,模型预测值与实际货架期验证比较,相对误差小于10%。所建预测模型可有效预测无光照下不同初始脂肪含量UHT牛奶货架期。
