Forbes Elizabeth M, Bakrania Bhavisha A, Steane Sarah E, Moritz Karen M, Lingwood Barbara E, Eiby Yvonne A
Queensland Children's Hospital, Brisbane, QLD, Australia.
UQ Centre for Clinical Research and Perinatal Research Centre, Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia.
Front Pediatr. 2022 Aug 23;10:891722. doi: 10.3389/fped.2022.891722. eCollection 2022.
Preterm infants are at increased risk of death and disability, and cardiovascular instability after birth is a contributing factor. Immaturity of calcium handling in the preterm heart may limit myocardial contractility and cardiac output. Two transmembrane cation channels, TRPM6 and TRPM7, may regulate intracellular cardiac calcium in the neonatal period. The aim of this study was to determine and mRNA expression in piglet hearts in late gestation, and the effects of sex, maternal glucocorticoids, and the transition to extrauterine life. Left and right ventricular tissue was collected at a range of gestational ages from cesarean delivered piglets at birth and at 6 h old. Additional groups included piglets exposed to maternal glucocorticoid treatment and spontaneously born term piglets at 12-24 h old. and mRNA expression was measured using RT-qPCR. Males had significantly lower expression in the left ventricle across all gestational ages compared to females. At term, both ventricles had higher expression at 6 h old than at birth. In preterm piglets, expression only increased postnatally in the right ventricle following maternal glucocorticoid exposure. At 12-24 h old, expression in both ventricles was lower than levels in 6 h old term Caesar piglets (113 days). Male preterm piglets may have immature myocardial Ca handling and this could contribute to their poorer outcomes. Increased expression is the mature response to birth that is missing in preterm neonates. could serve as a novel target to improve cardiac function in preterm neonates.
早产儿死亡和残疾风险增加，出生后心血管不稳定是一个促成因素。早产心脏中钙处理的不成熟可能会限制心肌收缩力和心输出量。两种跨膜阳离子通道TRPM6和TRPM7可能在新生儿期调节细胞内心脏钙。本研究的目的是确定妊娠晚期仔猪心脏中的 和mRNA表达，以及性别、母体糖皮质激素和向宫外生活转变的影响。在出生时和6小时大时，从剖宫产的仔猪中收集一系列胎龄的左右心室组织。其他组包括接受母体糖皮质激素治疗的仔猪和12 - 24小时大的自然出生的足月仔猪。使用RT - qPCR测量 和mRNA表达。与雌性相比，所有胎龄的雄性左心室中 表达均显著较低。足月时，两个心室在6小时大时的 表达均高于出生时。在早产仔猪中，仅在母体糖皮质激素暴露后，右心室的 表达在出生后增加。在12 - 24小时大时，两个心室中的 表达均低于6小时大的足月剖宫产仔猪（113天）。雄性早产仔猪可能心肌钙处理不成熟，这可能导致其预后较差。 表达增加是对出生的成熟反应，而早产新生儿中缺乏这种反应。 可作为改善早产新生儿心脏功能的新靶点。
