In vitro Examination of Piezo1-TRPV4 Dynamics: Implications for Placental Endothelial Function in Normal and Preeclamptic Pregnancies

Mechanosensation is essential for endothelial cell (EC) function, which is compromised in early-onset preeclampsia (EPE) impacting offspring health. The ion channels Piezo1 and TRPV4 are co-regulated mechanosensors in ECs. Here we show functional co-expression of both channels in feto-placental ECs (fpECs) and that calcium influx and membrane depolarization in response to chemical channel activation is reduced in EPE fpECs. Downstream of channel activation, Piezo1 alone can induce phosphorylation of endothelial nitric oxide synthase (eNOS) in fpECs, while combined activation of Piezo1 and TRPV4 only affects eNOS phosphorylation in EPE fpECs. Additionally, combined activation reduces the barrier integrity of fpECs, also with a stronger effect in EPE fpECs. This implies altered Piezo1-TRPV4 co-regulation in EPE. Mechanistically, we suggest this to be driven by changes in the arachidonic acid metabolism in EPE fpECs as identified by RNA-Seq. Targeting of Piezo1 and TRPV4 might hold potential for EPE treatment options in the future. Placentae were obtained immediately after delivery of singleton pregnancies at the Department of Obstetrics and Gynecology, Medical University of Graz, Austria. Collection and sample processing were approved by the ethics committee of the Medical University of Graz, Austria (29-319 ex 16/17) and voluntary detailed consent was taken from all study participants. Exclusion criteria were maternal systemic disease, other pregnancy complications, nicotine use during pregnancy, and a body mass index of <18 or >27 before pregnancy. The control samples were divided into two control groups: those delivered at ≥38 weeks of gestation called term controls (TC) and those delivered at <38 weeks of gestation called early controls (EC), the latter being age-matched to the early-onset PE group (EPE). EPE was diagnosed by a qualified clinician according to ACOG guidelines (new–onset hypertension with a blood pressure of ≥140/90 mmHg plus organ manifestation with onset of maternal symptoms <34 weeks of gestation). Clinical characteristics can be found in Table 1 of the repsective publication. For the study gene expression was compared between the groups.

机械感知对于内皮细胞（endothelial cell, EC）功能至关重要，而早发型子痫前期（early-onset preeclampsia, EPE）会破坏这一功能，进而影响子代健康。离子通道Piezo1与TRPV4是内皮细胞中共调控的机械感受器。本研究证实，这两种通道在胎儿胎盘内皮细胞（feto-placental ECs, fpECs）中存在功能性共表达；且在早发型子痫前期患者的胎儿胎盘内皮细胞中，化学通道激活所引发的钙内流与膜去极化反应均有所减弱。在通道激活的下游通路中，仅Piezo1即可诱导胎儿胎盘内皮细胞中的内皮型一氧化氮合酶（endothelial nitric oxide synthase, eNOS）磷酸化；而Piezo1与TRPV4联合激活仅会影响早发型子痫前期患者胎儿胎盘内皮细胞中的eNOS磷酸化水平。此外，联合通道激活会降低胎儿胎盘内皮细胞的屏障完整性，且该效应在早发型子痫前期患者的细胞中更为显著。这提示早发型子痫前期患者体内Piezo1-TRPV4的共调控机制发生了改变。从机制层面来看，本研究通过RNA测序（RNA-Seq）鉴定发现，早发型子痫前期患者的胎儿胎盘内皮细胞中花生四烯酸代谢的改变是该现象的驱动因素。靶向调控Piezo1与TRPV4有望为未来早发型子痫前期的治疗提供新策略。本研究的胎盘样本取自奥地利格拉茨医科大学妇产科的单胎妊娠产妇，均于分娩后即刻获取。样本采集与处理流程已获得奥地利格拉茨医科大学伦理委员会批准（审批编号：29-319 ex 16/17），所有研究参与者均自愿签署了详细的知情同意书。本研究的排除标准包括：产妇合并全身性疾病、存在其他妊娠并发症、孕期吸烟，以及孕前体重指数（body mass index, BMI）低于18或高于27。对照组样本分为两组：分娩孕周≥38周的足月对照组（term controls, TC），以及分娩孕周<38周的早期对照组（early controls, EC），后者与早发型子痫前期组（EPE）年龄匹配。早发型子痫前期由合格临床医师依据美国妇产科医师学会（American College of Obstetricians and Gynecologists, ACOG）指南进行诊断：妊娠<34周时出现新发高血压（血压≥140/90 mmHg）并伴随母体器官受累症状。研究的临床特征详见对应论文的表1。本研究对各组的基因表达水平进行了比较分析。