Abstract：
BACKGROUND: We herein examined changes in expression levels of the glucocorticoid receptor subtypes GRα and GRβ in very low birth weight (VLBW) and term infants to clarify time-dependent changes in glucocorticoid sensitivity after birth.
METHODS: Whole blood samples were collected at birth and on postnatal days 4-7, and the mRNA expression levels of GRα and GRβ were measured using RT-qPCR. The relative gene expression levels of GRα and GRβ as the target genes normalized to actin beta as the endogenous control were calculated by the comparative cycle threshold method.
RESULTS: The GRα/GRβ expression ratio at birth was significantly lower in 32 VLBW cesarean section (CS) infants than in term planned CS infants (median [IQR], 1.5 [1.1-1.8]- and 1.1 [0.7-1.6]-fold change, p < 0.05). Furthermore, the GRα/GRβ expression ratio increased from day 0 to days 4-7 (1.0 [0.6-1.4]- and 1.7 [0.6-1.4]-fold change, p < 0.01) in 43 VLBW infants.
CONCLUSIONS: The present results suggest that glucocorticoid sensitivity in VLBW infants increases after birth and this rapid change may play a role in surviving critical postnatal events.
METHODS: Whole blood samples were collected at birth and on postnatal days 4-7, and the mRNA expression levels of GRα and GRβ were measured using RT-qPCR. The relative gene expression levels of GRα and GRβ as the target genes normalized to actin beta as the endogenous control were calculated by the comparative cycle threshold method.
RESULTS: The GRα/GRβ expression ratio at birth was significantly lower in 32 VLBW cesarean section (CS) infants than in term planned CS infants (median [IQR], 1.5 [1.1-1.8]- and 1.1 [0.7-1.6]-fold change, p < 0.05). Furthermore, the GRα/GRβ expression ratio increased from day 0 to days 4-7 (1.0 [0.6-1.4]- and 1.7 [0.6-1.4]-fold change, p < 0.01) in 43 VLBW infants.
CONCLUSIONS: The present results suggest that glucocorticoid sensitivity in VLBW infants increases after birth and this rapid change may play a role in surviving critical postnatal events.
摘要：
本文研究了极低出生体重（VLBW）和足月婴儿糖皮质激素受体亚型GRα和GRβ表达水平的变化，以阐明出生后糖皮质激素敏感性的时间依赖性变化。方法在出生时和出生后第4至7天采集全血，并使用RT-qPCR检测GRα和GRβ的mRNA表达水平。通过比较循环阈值方法计算作为靶基因的Grα和Grβ的相对基因表达水平,所述靶基因标准化为作为内源性对照的肌动蛋白β。结果32例VLBW剖宫产（CS）婴儿出生时的GRα/GRβ表达比率显着低于足月计划CS婴儿（中位数（IQR），1.5(1.1-1.8)-和1.1(0.7-1.6)-倍数变化，p<0.05)。此外，从第0天到第4天到第7天，GRα/GRβ表达比率增加（1.0（0.6-1.4）-和1.7（0.6-1.4）-倍变化，43例VLBW婴儿的p<0.01）。讨论/结论目前的结果表明，VLBW婴儿出生后糖皮质激素敏感性增加，这种快速变化可能在严重的产后事件中发挥作用。
