Prenatal air pollution exposure is linked to congenital heart defects (CHD), while the underlying molecular mechanisms remain poorly understood. Here we showed that maternal exposure to PM2.5, PM10, and NO2 was significantly associated with increased CHD risk during the periconception period, with NO2 exhibiting the strongest effect. Moreover, a supervised sparse partial least square model identified pollutant-specific protein signatures in both maternal serum and umbilical cord serum. These protein fingerprints could effectively reflect the levels of air pollution and were significantly associated with CHD outcomes. Notably, our study revealed that FGF-4, VEGF-D, MSP, and Angiogenin may be involved in air pollution-associated cardiac malformations. Overall, this study promotes the understanding of the association between air pollution and CHD by identifying susceptible populations and underlying molecular mechanisms, providing a scientific basis for mitigation policies and prenatal healthcare.

Human placentation relies on the precise differentiation of embryo-derived trophoblasts into specialized lineages, a process strictly regulated by the spatio-temporal expression of key genes. Herein, we report that the expression of the transmembrane glycoprotein, known as E-cadherin, fluctuates dynamically across distinct trophoblast subpopulations rather than acting as a static structural tether. Along the villous pathway, E-cadherin expression initially increases to facilitate the aggregation of cytotrophoblast cells (CTs) and is subsequently downregulated via transcriptional repression, enzymatic cleavage and physical compressive forces for the CTs to fuse into the syncytiotrophoblast lineage. Conversely, along the extravillous pathway, its transient downregulation characterizes an epithelial-to-mesenchymal transition that permits trophoblast invasion into the decidua, followed by its upregulation in the endovascular trophoblasts to potentially facilitate vascular adhesion and spiral artery remodeling. Dysregulation of this expression pattern of E-cadherin is evident in the placenta of pregnancies complicated by preeclampsia or fetal growth restriction. To advance the field, future research must transition from descriptive profiling to functional mechanisms by defining the precise intracellular degradation pathways of E-cadherin in trophoblast lineages and then clarify whether the upstream regulators operate in linear or parallel networks. Utilizing advanced biophysical tools and spatial transcriptomics will help clarify how tissue stiffness, fluid shear stress, and local immune cells mechanically and immunologically trigger this E-cadherin switch via mechanosensitive channels. Translational studies should explore the feasibility of using circulating soluble E-cadherin fragments in maternal blood as an early biomarker of defective placentation.

Stress during the prenatal period increases the risk in the next generation for negative health outcomes, including cardio-metabolic dysfunction and psychiatric diseases. To standardize prenatal exposure to stress hormone levels, we administered corticosterone (20 mg/kg s.c.) chronically (C-CORT) to pregnant mouse dams daily from gestational day 12-18. We monitored physiological, neural, and behavioral endpoints in dams and their offspring at adolescence and adulthood. Dams treated with C-CORT displayed increased anxiety-like behavior and altered maternal behavior, including increased time to retrieve pups and preference for male pup odor. These behavioral changes were accompanied by increased circulating corticosterone and increased expression of mineralocorticoid receptors in perifornical area urocortin-3-expressing neurons. In offspring, we identified age- and sex-specific differences: female adolescent mice exposed to prenatal C-CORT showed enhanced novel object recognition, while adult female offspring exposed to prenatal C-CORT showed increased immobility and reduced locomotion in an open-field arena. Adult female offspring exposed to prenatal C-CORT also lacked female-typical elevation in basal circulating corticosterone levels and showed increased hippocampal expression of corticotropin-releasing factor receptor 1 (CRFR1) in the hippocampus. Reciprocal cross-fostering normalized the effects of prenatal C-CORT exposure on adult female offspring open-field immobility, basal corticosterone, and hippocampal CRFR1 expression, but did not reverse hypoactivity. Moreover, males prenatally treated with vehicle then reared by C-CORT-treated dams exhibited greater anxiety-like behavior. These findings strengthen the idea that both fetal programming and postnatal maternal environment contribute to sex-specific neurobiological, endocrine, and behavioral outcomes in offspring.

The 2015-2016 Zika virus (ZIKV) epidemic revealed the potential of flaviviruses to emerge rapidly, cause severe disease, and affect pregnancy outcomes. In 2016, Spondweni virus (SPOV), the closest known relative of ZIKV, was detected in mosquitoes in Haiti, suggesting it may also have the potential to emerge in the Western Hemisphere. The risks that close relatives of ZIKV pose to pregnant individuals are not well understood. Previously, we showed that SPOV can cause fetal demise, placental pathology, and vertical transmission in a mouse model. Here we report SPOV's pathogenic potential in pregnant rhesus macaques. We inoculated four macaques with SPOV at gestational day 30 (early first trimester) and compared their viral loads and fetal outcomes with those of macaques infected in the first trimester with either African-lineage ZIKV (ZIKV-DAK) or an Asian-lineage ZIKV isolate from Puerto Rico (ZIKV-PR) in previous studies. Plasma viremia persisted 10-31 days in SPOV-inoculated dams, whereas viremia resolved within 10-17 days for ZIKV-DAK and 5-52 days for ZIKV-PR. Cesarean deliveries near term (gestational day 152-157) revealed no demise, premature birth, or gross abnormalities in fetuses of dams inoculated with SPOV or ZIKV-PR. In contrast, under near-identical conditions, all ZIKV-DAK-inoculated dams experienced fetal demise between 12 and 20 days post-inoculation. At cesarean section, we did not detect SPOV RNA above the limit of detection in maternal (e.g., spleen, liver), placental, or fetal tissues, in contrast to previous findings with ZIKV-PR. Histological analysis revealed mononuclear/lymphohistiocytic villitis in all placentas of SPOV-exposed macaques, along with other pathological changes in individual placentas. Our findings suggest that SPOV infection of macaques in early pregnancy may result in placental pathology without overt fetal harm. Our results suggest that flaviviruses in the Spondweni serocomplex, which includes ZIKV and SPOV, may vary in their pathogenic potential during pregnancy.

Thymic macrophages (TMs) maintain tissue homeostasis by clearing the large numbers of apoptotic cells generated during T cell development, but how TM heterogeneity relates to their developmental origin and role in thymocyte maturation remains incompletely understood. Using complementary flow-cytometric, single-cell transcriptomic, and genetic approaches, we resolved two major TM populations corresponding to TIMD4[+] cortical and CX3CR1[+] medullary/cortico-medullary macrophages. TIMD4[+] VCAM1[+] TMs displayed a prominent efferocytosis and apoptotic-cell-clearance program, whereas TIMD4[-] VCAM1[+] TMs were enriched for antigen-presentation and interferon-response pathways. Fate mapping revealed unequal progenitor contributions to these populations, and CCR2 deficiency selectively reduced TIMD4[-] VCAM1[+] TMs, and thymic monocytes, supporting ongoing input from circulating precursors. Exploratory pseudotime analysis further identified a transcriptional continuum from Ly6c2[+]Ccr2[+] monocytes toward macrophage states. Using MaFIA fetal thymic organ cultures, AP20187-mediated depletion of Csf1r-expressing myeloid cells reduced CD4[+]CD8[+] thymocyte differentiation and produced a coordinated accumulation of DN3 cells, loss of DN4 cells, and reduction in CD27 expression. These convergent changes identify the DN3-to-DN4 transition as a developmental stage that requires an intact Csf1r-expressing myeloid compartment and establish a functional connection between the thymic myeloid niche and early αβ T cell development. Together, our study refines the phenotypic and developmental organization of mouse TMs and reveals a previously underappreciated requirement for myeloid-cell support during progression through the β-selection checkpoint.

Early human pregnancy (11-15 weeks) is a critical period when placental dysfunction begins but remains clinically undetectable, preventing early intervention for pregnancy complications. This highlights a pressing need for circulating biomarkers that can signal the onset of a complication. Circulating extracellular vesicles (EVs) carry bioactive cargo that reflect originating cell activity in real-time, positioning them as early biomarkers of pregnancy complications. While pregnancy studies have identified plasma EV cargo alterations across complications, studying small EVs alone-the field standard-or bulk EVs together obscures pathological changes that may manifest preferentially in one population. To address this, we performed the first multi-omic comparison of small and large plasma EVs from healthy pregnancies at 11-13 weeks (n=10) to establish subtype-specific cargo differences and provide a reference for normal pregnancy EV biology. We quantified mitochondrial DNA (mtDNA), performed transcriptomics (mRNAs, miRNAs) and proteomics to define small and large EV signatures. Large EVs were preferentially enriched for mitochondrial cargo including DNA, transcripts, and proteins as well as hypoxia response, endocrine signaling, and VEGF signaling related transcripts and proteins. In contrast, small EVs were enriched for canonical EV markers and basement membrane proteins. Additionally, we found that EV miRNA composition was similar across EV subtypes with only 7 miRNAs differentially abundant between small and large EVs. These distinct small and large EV cargo signatures underscore the importance of profiling both populations for liquid biopsy potential. Together these data provide a baseline for future studies linking EV signature alterations to placental dysfunction and adverse pregnancy outcomes.

Cardiovascular diseases remain the leading cause of morbidity and mortality worldwide; however, effective clinical therapies that achieve myocardial regeneration are still lacking, underscoring the urgent need for novel therapeutic strategies. In this study, we identified an RNA-binding protein Ptbp1, a key component of RNA metabolism, as a critical regulator of cardiomyocyte proliferation via the formation of biomolecular condensates. We found that Ptbp1 exhibits granule-like structures in cardiomyocyte nuclei during fetal to early postnatal stages. These Ptbp1 foci are phase-separated liquid droplets formed via its multivalent RNA binding domains. Functional analyses revealed that Ptbp1 is essential for cardiomyocyte proliferation in neonatal mouse primary culture assays. Furthermore, proximity labeling using a primary antibody-based approach combined with RIP-seq in highly purified cardiomyocyte populations demonstrated that these condensates are enriched with multiple proliferation-associated factors. Our findings identify a novel phase-separated condensate in cardiomyocytes and provide a new potential therapeutic target for cardiac regeneration.

Preeclampsia (PE) is characterized by hypertension, endothelial dysfunction, and reduced nitric oxide (NO) bioavailability. Asymmetric dimethylarginine (ADMA), an endogenous inhibitor of endothelial NO synthase, is elevated in PE and contributes to vascular dysfunction. NO may regulate ADMA production. NO formation from nitrite occurs under hypoxic-ischemic conditions. Thus, this study investigated whether sodium nitrite attenuates circulating ADMA levels and vascular endothelial dysfunction in placental ischemia induced by reduced uteroplacental perfusion pressure (RUPP) in pregnant rats.

Noninvasive prenatal testing (NIPT) is a pregnancy screening test that analyses cell-free fetal DNA (cffDNA) in maternal plasma to detect fetal genetic abnormalities during pregnancy. Earlier and safer detection of fetal genetic abnormalities facilitated by NIPT has markedly transformed maternal-fetal medicine. However, NIPT is currently limited to be only a screening test due to fundamental biological bottlenecks, namely, the small proportion of cffDNA compared to cell-free maternal DNA in maternal plasma, the challenge to reliably distinguish between fetal and maternal DNA, and discordance between cffDNA and the true fetal genotype. Despite millions of NIPT being conducted each year, the exact origin and structural topology of cffDNA remain unexpectedly unclear. Elucidating the origin and structure of cffDNA could unlock new technological advances that address the current bottlenecks limiting NIPT toward realizing the full potential of state-of-the-art sequencing approaches for NIPT. In this Review, we critically discuss current cffDNA knowledge, including its origin, release into maternal blood circulation, and structures relevant to contemporary NIPT.

Chronic inflammation during pregnancy is a persistent, often subclinical condition strongly associated with adverse maternal and fetal outcomes. Its etiology is multifactorial, with exposure to exogenous environmental stressors emerging as major contributors, yet the underlying mechanisms remain unclear. Here, we report gestational chronic inflammation induced by exposure to realistic doses of phthalate replacement diisononyl phthalate (DINP), a ubiquitous environmental stressor, during pregnancy via drinking water using a murine model. We demonstrated for the first time that exposure provoked systemic and hepatic inflammation, evidenced by elevated circulating inflammatory cytokines and pronounced hepatic immune cell infiltration. Transcriptomic and oxidized lipidomic profiling further revealed disrupted polyunsaturated fatty acid metabolism and a storm of excessive arachidonic acid oxidation-derived proinflammatory oxylipins, particularly prostaglandins, produced by the liver as key mediators of environmental stress-induced inflammation. Specifically, exposure hyperactivated hepatic cyclooxygenase-2 (COX-2) without altering its protein abundance, which initiated excessive production of proinflammatory oxylipins in the liver. Notably, celecoxib, a selective COX-2 activity inhibitor, effectively suppressed oxylipin overproduction and mitigated both systemic and hepatic inflammation. These findings uncovered a previously unrecognized environmental stressor-COX-2-oxylipin pathway linking environmental exposure and maternal chronic inflammation, highlighting an emerging public health concern.

Cardiovascular health among the US general population remains largely suboptimal. Major contributing factors include diet, physical activity, and sleep, and these influences begin early in life, despite broad access to health information regarding healthy choices and access to medical care. Advances in perinatal care allow earlier detection of both maternal and congenital conditions, enabling interventions and planning that can improve outcomes. Research exploring the foundations of hypoplastic left heart syndrome (HLHS) has significantly expanded in the last 25 years. HLHS represents a prototypical complex congenital heart defect arising from multifactorial perturbations in left-sided cardiac development, with converging contributions from genetic susceptibility, dysregulated signaling pathways, and environmental modifiers. Early diagnosis, now largely achieved through fetal and postnatal echocardiography, enables timely identification of ductal-dependent systemic circulation and facilitates coordinated perinatal management strategies. Contemporary management remains rooted in staged single-ventricle palliation or cardiac transplantation, supported by intensive perioperative care aimed at maintaining systemic perfusion and improving survival, albeit with significant long-term morbidity. Increasingly, advances in genomics and molecular cardiology are redefining the field, with patient-specific cellular models and pathway-targeted approaches offering the potential to uncover disease mechanisms and develop novel, mechanism-based therapies that move beyond surgical palliation. This review summarizes current knowledge on the etiology of HLHS, current treatments, and emerging therapeutic strategies, with emphasis on the potential for modulation of EFNA/EphA signaling to influence multiple aspects of disease progression.

Human pregnancy unfolds in a unique mosaic tissue context. Embryonic/fetal placental and maternal uterine cells (decidua basalis) coalesce, forming the basal plate where immune tolerance is coordinated and the utero-placental circulation is initiated. The remaining approximately 70% of the maternal-fetal interface is comprised of the chorionic membranes, an epithelial-like layer of placental cells that lies adjacent to but does not coalesce with the overlying decidua capsularis and parietalis. It is unknown how these two regions of the maternal-fetal interface, which are comprised of seemingly similar cell types, diverge anatomically and functionally. Likewise, it is unknown whether the molecular characteristics of the maternal-fetal interface vary across human populations, potentially contributing to population disparities in pregnancy complications. Here, we generated large-scale paired single-nucleus RNA-seq and chromatin-accessibility profiles of the basal plate and chorionic membranes-associated decidual compartments from diverse-ancestry pregnancies, integrated with spatial transcriptomics and multiplexed protein imaging. We show that the two interfaces share a conserved cytotrophoblast differentiation hierarchy, which is deployed differently resulting in the observed distinct architectures. In the chorionic membranes, progenitor, early, and mature extravillous cytotrophoblast (EVT) states form an epithelial-like laminar shell. In the basal plate, this hierarchy is elaborated upon to enable deep placentation: EVTs that arise early in pregnancy invade the farthest into the uterus, while mature EVTs accumulate superficially to sculpt the local maternal immune microenvironment. Comparative analysis identified DSC4, a decidual stromal cell subtype, as an anti-invasive barrier that is densely enriched adjacent to the chorionic membranes but substantially reduced at the basal plate. Population-resolved analysis further identified the DSC4 marker NID2 , which encodes the basement-membrane glycoprotein nidogen-2, as an ancestry-associated rheostat of EVT invasion. A specific NID2 promoter haplotype arose on the modern-human lineage, is absent from available archaic-human genomes, and shows evidence of positive selection in Eurasian populations. This haplotype is associated with reduced local chromatin accessibility and lower NID2 expression in DSC4 cells. Consistent with this genetic association, extracellular NID2 directly suppressed the invasion of primary human cytotrophoblasts in vitro . Together, these findings reveal how a shared developmental program is spatially reconfigured across distinct regions of the maternal-fetal interface and identify a recent modern-human regulatory innovation that modulates maternal decidual restraint of fetal trophoblast invasion across populations.