Downregulation of miR-1270 mediates endothelial progenitor cell function in preeclampsia: Role for ATM in the Src/VE-cadherin axis

Alternative splicing of CADM1 is associated with endothelial progenitor cell dysfunction in preeclampsia

Preeclampsia is a pregnancy-specific hypertensive disorder and is associated with an increased postpartum risk of cardiovascular morbidity for both women and their offspring. Previous studies have indicated that cord blood endothelial colony-forming cells (ECFCs) are dysfunctional in preeclampsia. The specific mechanisms are not yet fully understood, but dysregulation of alternative splicing has been proposed as one of the pathogenic pathways. To identify specific targets of alternative splicing in fetal ECFCs, we performed transcriptome-wide differential splicing analyses between cord blood ECFCs from preeclamptic (n = 16) and normal pregnancies (n = 13). Selected splicing events were validated using fragment length analysis and Sanger sequencing. In silico transcriptome-wide differential splicing analysis identified a significantly increased abundance of the CADM1 isoform ENST00000542447 in the preeclamptic cohort (P = 0.002), which was confirmed by wet-lab validation. The deleted exon 8 harbors glycosylation sites known to mediate cell-cell adhesion. To investigate the functional impact of alternative splice variants, we induced an in vitro splice switch using antisense morpholino treatment and then monitored cellular effects using migration and angiogenesis assays in ECFCs from six normal pregnancies. The CADM1 exon 8 skipping converted the normal ECFCs to a preeclampsia-like state characterized by a decreased migration ability (PANOVA = 0.005) and decreased tubule length (PANOVA = 0.02). We propose aberrant splicing of CADM1 and the resulting changes in the adherence properties of ECFCs as a potential contributor to cardiovascular sequelae in the offspring of preeclamptic pregnancies.NEW & NOTEWORTHY We investigated differential splicing between normal and preeclamptic pregnancies in endothelial colony-forming cells (ECFCs) from cord blood. Transcriptome-wide analysis identified exon 8 skipping of CADM1 mRNA to be upregulated in ECFCs from women with preeclampsia. In vitro splice switching studies indicated that induction of this isoform decreases the cell migration and tubule formation abilities of fetal ECFCs. Our findings link a specific splice isoform of CADM1 to preeclampsia, with potential implications for vascular health in the offspring.

The vascular phenotype of BPD: new basic science insights-new precision medicine approaches

Bronchopulmonary dysplasia (BPD) is the most common complication of preterm birth. Up to 1/3 of children with BPD develop pulmonary hypertension (PH). PH increases mortality, the risk of adverse neurodevelopmental outcome and lacks effective treatment. Current vasodilator therapies address symptoms, but not the underlying arrested vascular development. Recent insights into placental biology and novel technological advances enabling the study of normal and impaired lung development at the single cell level support the concept of a vascular phenotype of BPD. Dysregulation of growth factor pathways results in depletion and dysfunction of putative distal pulmonary endothelial progenitor cells including Cap1, Cap2, and endothelial colony-forming cells (ECFCs), a subset of vascular progenitor cells with self-renewal and de novo angiogenic capacity. Preclinical data demonstrate effectiveness of ECFCs and ECFC-derived particles including extracellular vesicles (EVs) in promoting lung vascular growth and reversing PH, but the mechanism is unknown. The lack of engraftment suggests a paracrine mode of action mediated by EVs that contain miRNA. Aberrant miRNA signaling contributes to arrested pulmonary vascular development, hence using EV- and miRNA-based therapies is a promising strategy to prevent the development of BPD-PH. More needs to be learned about disrupted pathways, timing of intervention, and mode of delivery. IMPACT: Single-cell RNA sequencing studies provide new in-depth view of developmental endothelial depletion underlying BPD-PH. Aberrant miRNA expression is a major cause of arrested pulmonary development. EV- and miRNA-based therapies are very promising therapeutic strategies to improve prognosis in BPD-PH.

Recent advances in endothelial colony-forming cells: from the transcriptomic perspective

Endothelial colony-forming cells (ECFCs) are progenitors of endothelial cells with significant proliferative and angiogenic ability. ECFCs are a promising treatment option for various diseases, such as ischemic heart disease and peripheral artery disease. However, some barriers hinder the clinical application of ECFC therapeutics. One of the current obstacles is that ECFCs are dysfunctional due to the underlying disease states. ECFCs exhibit dysfunctional phenotypes in pathologic states, which include but are not limited to the following: premature neonates and pregnancy-related diseases, diabetes mellitus, cancers, haematological system diseases, hypoxia, pulmonary arterial hypertension, coronary artery diseases, and other vascular diseases. Besides, ECFCs are heterogeneous among donors, tissue sources, and within cell subpopulations. Therefore, it is important to elucidate the underlying mechanisms of ECFC dysfunction and characterize their heterogeneity to enable clinical application. In this review, we summarize the current and potential application of transcriptomic analysis in the field of ECFC biology. Transcriptomic analysis is a powerful tool for exploring the key molecules and pathways involved in health and disease and can be used to characterize ECFC heterogeneity.

Fetal endothelial colony-forming cells: Possible targets for prevention of the fetal origins of adult diseases

Endothelial colony-forming cells (ECFCs), a subset of circulating and resident endothelial progenitor cells, are capable of self-renewal and de novo vessel formation, and are known key regulators of vascular integrity and homeostasis. Numerous studies have found that exposure to hostile environment during the fetal development exerts a profound influence on the level and function of ECFCs, which may be the underlying factor linking endothelial dysfunction to cardiovascular disease of the offspring in later life. Herein, we focus on the latest findings regarding the effects of pregnancy-related disorders on the frequency and function of fetal ECFCs. Subsequently, we discuss about placental ECFCs and put forward some details that should be paid attention to in the process of ECFC isolation and culture. Overall, the information presented in this review highlight the potential of ECFCs as a future biomarker or even therapeutic targets for the pregnancy-related adverse maternal and fetal outcomes.

Endothelial progenitor cells in pregnancy-related diseases

Placental neovascularization plays a crucial role in fetomaternal circulation throughout pregnancy and is dysregulated in several pregnancy-related diseases, including preeclampsia, gestational diabetes mellitus, and fetal growth restriction. Endothelial progenitor cells (EPCs) are a heterogeneous population of cells that differentiate into mature endothelial cells, which influence vascular homeostasis, neovascularization, and endothelial repair. Since their discovery in 1997 by Asahara et al., the role of EPCs in vascular biology has garnered a lot of interest. However, although pregnancy-related conditions are associated with changes in the number and function of EPCs, the reported findings are conflicting. This review discusses the discovery, isolation, and classification of EPCs and highlights discrepancies between current studies. Overviews of how various diseases affect the numbers and functions of EPCs, the role of EPCs as biomarkers of pregnancy disorders, and the potential therapeutic applications involving EPCs are also provided.