Altered placental ion channel gene expression in preeclamptic high-altitude pregnancies
Year: 2023
Type: article
Study design: Observational Study
Abstract: High-altitude (>2,500 m) residence increases the risk of pregnancy vascular disorders such as fetal growth restriction and preeclampsia, each characterized by impaired placental function. Genetic attributes of highland ancestry confer relative protection against vascular disorders of pregnancy at high altitudes. Although ion channels have been implicated in placental function regulation, neither their expression in high-altitude placentas nor their relationship to high-altitude preeclampsia has been determined. Here, we measured the expression of 26 ion-channel genes in placentas from preeclampsia cases and normotensive controls in La Paz, Bolivia (3,850 m). In addition, we correlated gene transcription to maternal and infant ancestry proportions. Gene expression was assessed by PCR, genetic ancestry evaluated by ADMIXTURE, and ion channel proteins localized by immunofluorescence. In preeclamptic placentas, 11 genes were downregulated ( ABCC9, ATP2A2, CACNA1C, KCNE1, KCNJ8, KCNK3, KCNMA1, KCNQ1, KCNQ4, PKD2, and TRPV6) and two were upregulated ( KCNQ3 and SCNN1G). KCNE1 expression was positively correlated with high-altitude Amerindian ancestry and negatively correlated with non-high altitude. SCNN1G was negatively correlated with African ancestry, despite minimal African admixture. Most ion channels were localized in syncytiotrophoblasts (Cav1.2, TRPP2, TRPV6, and Kv7.1), whereas expression of Kv7.4 was primarily in microvillous membranes, Kir6.1 in chorionic plate and fetal vessels, and MinK in stromal cells. Our findings suggest a role for differential placental ion channel expression in the development of preeclampsia. Functional studies are needed to determine processes affected by these ion channels in the placenta and whether therapies directed at modulating their activity could influence the onset or severity of preeclampsia.
Source: Physiological Genomics
Institutions: University of Colorado Anschutz, University of O'Higgins
Language: English
Subfield: Obstetrics and Gynecology
Field: Medicine
Domain: Health Sciences
Open Access status: green
Awards: Myometrial artery potassium channel activity in intrauterine growth restriction pregnancy, Epigenetic and Fetal Origins of Hypoxia-Induced Pulmonary Hypertension, Antenatal Exposures and Non-Communicable Disease(ANDES): Building research capacity to identify and treat causes of NCD in Bolivia, Effects of chronic hypoxia and AMPK activation on uteroplacental perfusion, placental metabolism and the regulation of fetal growth, Health AI and Data Science in Cardiovascular and Pulmonary Disease: Application and Bioethics (HARP-BIO)
OpenAlex ID: W4384523824