Search Results (140)

This systematic review assessed transcriptomic evidence on the molecular mechanisms underlying spontaneous preterm birth (sPTB). Major electronic databases were searched from inception to October 2025. Eligible studies examined RNA transcriptomic profiles from maternal pregnancy-related tissues or biofluids in spontaneous preterm labor (sPTL) or preterm prelabor rupture of membranes (PPROM), while indicated or iatrogenic preterm births were excluded. Two reviewers independently screened studies, extracted differentially expressed genes (DEGs), and assessed study quality. DEGs were summarized by tissue type, and recurrent concordant genes were analyzed using Gene Ontology, Reactome, and Kyoto Encyclopedia of Genes and Genomes enrichment analyses, with false discovery rate < 0.05 considered significant. Twenty studies were included. Transcriptomic data were derived from placental villi, maternal peripheral blood, decidua, fetal membranes, myometrium, amniotic fluid, and vaginal secretions. Placental villi findings suggested proliferative-metabolic reprogramming and impaired maternal–fetal immune–structural homeostasis, whereas maternal blood profiles reflected systemic immune–inflammatory activation and dysregulated lipid-metabolic pathways. sPTL and PPROM showed potentially distinct signatures involving extracellular matrix disruption, collagen remodeling, matrix degradation, and myeloid/neutrophil-associated inflammation. Transcriptomic profiling may support non-invasive sPTB risk assessment, but standardized, phenotype-specific longitudinal studies are needed to confirm predictive value and clinical utility. Full article

Essential host functions are often maintained by conserved molecular systems, but in biological contexts shaped by evolutionary conflict, the genes that execute such functions may be unstable, replaceable, or repeatedly recruited from different evolutionary sources. Mammalian placentation provides a striking example of this principle. Trophoblast cell fusion is essential for placental development, yet this function is mediated in different mammalian lineages by distinct endogenous retrovirus-derived envelope proteins, including syncytin-1, syncytin-2, and other lineage-specific Env-derived fusogens. Here, I propose the Baton Pass model as a conceptual framework for explaining how host-level biological functions can be maintained despite turnover of the molecular agents that execute them. This model differs from conventional examples of antagonistic coevolution, which often emphasize recurrent mutations within the same interacting genes, and from non-orthologous gene displacement, which generally concerns replacement among cellular genes. In the syncytin paradigm, the molecular executors are repeatedly supplied by exogenous retroviral env genes that become endogenized, domesticated, and incorporated into host developmental programs. I further discuss how receptor compatibility, placental expression control, and host–virus evolutionary conflict may together destabilize individual Env–receptor systems while allowing the host-level function of trophoblast fusion to persist. Analogous functional reassignment is also observed in primate lentiviruses, where antagonism of BST-2 shifts among distinct viral genes. The Baton Pass model therefore describes a testable evolutionary principle: essential host functions can be preserved not only through conservation of specific genes, but also through dynamic succession of genes of distinct evolutionary origins. Full article

Background/Objectives: Autophagy is a highly conserved eukaryotic cellular process whose dysfunction results in human pathologies including cancer and neurodegenerative disease. First identified in yeast, ATG genes are central players in autophagy. Mutations in core autophagy genes ATG5 and ATG7 have been previously reported to cause rare genetic disorders with autosomal recessive inheritance. Methods: Here we report, for the first time, variants in human ATG9B gene as causative factors for a rare neurodevelopmental disease with autosomal recessive inheritance. Three distinct mutations were detected in three independent families with consanguinity, five patients affected in total. Results: The first variant is an 11-nucleotide deletion resulting in a frameshift. A premature stop codon is added and the C-terminal cytosolic domain of ATG9B protein is truncated. The second one is a point mutation that changes a critical amino acid in the transmembrane domain. The third variant is a 2-nucleotide deletion causing a different truncation product. Patients presented with diverse neurodevelopmental anomalies including intellectual disability, behavioral abnormalities, congenital cerebellar ataxia, mild cerebellar atrophy, and microcephaly. Since human ATG9B is expressed specifically in the placenta, we hypothesized that the disease pathology originates during placental development. To characterize the effects of the first frameshift mutation and gain insight into the specific functions of ATG9B in a physiological setting, we used mammalian cells and a knock-in mouse model. Truncated ATG9B was not stable when expressed in cells. It was localized to perinuclear vesicles like the WT protein, but not to peripheral vesicles. Homozygous knock-in mice were viable, fertile, and displayed no gross phenotypical abnormalities. Histomorphometry analysis of the placenta layers did not reveal a significant difference between mutant and control embryos. The assessments of neurobehavioral tests were similar in wild-type and homozygous knock-in mice. However, knock-in mice had a reduced fear memory trend, which is an amygdala-involved response. Conclusions: In this study, we describe a new rare disease linked to ATG9, including cerebellar ataxia and atrophy, as described for ATG5 and ATG7. Full article

Early mammalian embryos are highly sensitive to environmental, metabolic, hormonal, and genomic stress, yet embryo assessment during In Vitro Fertilization (IVF) relies largely on morphology and ploidy for embryo assessment, but these tests incompletely predict miscarriage. We present a transcriptomics based framework to classify and quantify lineage-specific stress in early embryos by benchmarking human preimplantation embryos against dose-, time-, and quality-dependent stress programs defined in Embryonic and placental Trophoblast Stem Cells (ESCs, TSCs) from the implanting blastocyst. Human embryos and stressed ESCs and TSCs are screened using transcriptomic markers from eleven biologically distinct stress Gene Ontology (GO) groups that define functional stress states and enable quantification of pathway presence and upregulation, pathway activity, and downstream outcomes. This framework determines whether the Integrated Stress Response (ISR), once initiated, resolves to enable the Developmentally Associated Stress Response (DASR). High-throughput screening (HTS) titrates stress to define increasingly risky yet biologically equivalent doses for levels of diminished stem cell growth across mechanistically diverse stressors. Then bulk RNA seq derives lineage specific transcriptomic markers putatively respond to common levels of diminished growth and that distinguish weak vs. strong stress and resolved vs. unresolved ISR. These stem cell transcriptomic signatures are applied to bulk RNA seq data from IVF embryos graded for morphology or adhesion, enabling quantitative inference of stress burden, lineage vulnerability, and developmental trajectory. Full article

Background: Gestation is a period of significant biological plasticity where the intrauterine environment influences fetal development via “fetal programming”. This study systematically reviews and meta-analyzes the association between genetic determinants—specifically the NR3C1, FKBP5, and CRHR1 genes, chosen for their pivotal role in the functional regulation and feedback sensitivity of the hypothalamic–pituitary–adrenal (HPA) axis—and stress reactivity during pregnancy. Methods: Following PRISMA guidelines, a systematic search was conducted across PubMed, Scopus, and Web of Science, yielding an initial total of 1430 records. After removing duplicates and screening 669 studies, a total of 34 primary observational studies were included in the systematic review and qualitative synthesis. For the quantitative synthesis, 27 articles provided sufficient data, resulting in k = 39 independent effect sizes analyzed via a mixed-effects model to account for tissue-specific and cohort-specific outcomes. Results: Systematic analysis reveals that maternal psychosocial stress significantly correlates with NR3C1 hypermethylation, acting as a biological mediator for neonatal cortisol dysregulation and hippocampal volume reduction. The FKBP5 rs1360780 polymorphism emerged as a key moderator of structural vulnerability, showing a “double-hit” effect when combined with epigenetic alterations. Furthermore, the study identifies sex-specific susceptibility, with divergent placental trajectories for male and female fetuses. Meta-analytic estimates confirmed the robustness of these associations (Rosenthal Fail-Safe N = 431,000), despite a general trend toward statistical significance (p = 0.079) in heterogeneous cohorts. Conclusions: The findings underscore a stable link between genetic determinants and prenatal stress reactivity. The interaction between molecular predisposition and environmental factors defines the health of the mother–infant dyad. These results advocate for a transition toward Precision Prenatal Medicine, integrating polygenic risk scores and epigenetic monitoring to implement early, targeted preventive interventions. Full article

Peroxisome proliferator-activated receptor γ (PPARγ), encoded by the PPARG gene on chromosome 3p25.2 in humans, is a ligand-dependent transcription factor that belongs to the nuclear receptor family. In various tissues, PPARγ controls cell differentiation, proliferation, or fusion. Its essential role in the development and functions of the placenta is now well established. To date, the specific functions of its RNA isoforms, encoded by ten exons, in trophoblast biology, including cell fusion and invasion, remain unknown. As translation is mainly regulated by the 5′UTR sequences of mature mRNA, this region was analyzed, and four previously unreported exonic sequences were revealed. Their expressions were confirmed and quantified in villous cytotrophoblasts from term placenta and in chorionic villi from both first-trimester and term placenta. Distinct expression patterns were observed: one exon showed weak expression in placental and chorionic cells, another exhibited stable expression throughout pregnancy, while two exons specific to villous cytotrophoblasts displayed increased expression during the first trimester, suggesting a role in oxygen-responsive mechanisms. Among these, one may be involved in villous trophoblast differentiation. These findings demonstrate that the PPARG gene is composed of 14 exons and is highly regulated depending on cell type and the stage of cell differentiation. Full article

Preeclampsia (PE) is a leading cause of maternal and perinatal complications and is classified by early or late onset according to the gestational age. The complex pathogenesis of PE involves placental ischemia, oxidative stress, angiogenic imbalance, and inflammation, all of which contribute to impaired placentation and widespread maternal endothelial dysfunction. These mechanisms drive hypertension, multi-organ involvement, and increased long-term cardiovascular risk. Parallel research highlighted the role of the NLRP3 inflammasome, a multiprotein complex that, upon activation, increases the gene expression, processing, and release of the pro-inflammatory cytokines IL-1β and IL-18. The NLRP3 pathway is markedly upregulated in placentas from pregnant women with PE, where endogenous danger signals stimulate inflammasome activation and amplify inflammation. Increasing evidence indicates that microRNAs (miRNAs) help regulate inflammatory processes, including the NLRP3 inflammasome, thereby affecting placental function and maternal adaptation. Although several immunoregulatory miRNAs may influence NLRP3 activity, their specific contribution to inflammasome regulation in PE remains insufficiently understood. Understanding these interactions could reveal new therapeutic targets for PE. In this narrative review, we explore the interconnected roles of endothelial dysfunction, inflammasome activation, and miRNA-mediated regulation in the pathogenesis of PE. Full article

Background/Objectives: Pregnancy loss is a common and multifactorial complication of human reproduction, traditionally attributed to fetal chromosomal abnormalities, maternal anatomical and endocrine disorders, and immune dysfunction. Growing evidence now indicates that the maternal microbiome, particularly within the reproductive tract, plays a critical role in implantation, placental development, and the maintenance of immune tolerance during early pregnancy. Importantly, the influence of the microbiome on miscarriage appears to be strongly modulated by host genetic background and immune regulation. Methods: This narrative review summarizes current evidence linking alterations in the vaginal, endometrial, placental, and gut microbiomes to miscarriage, with a specific focus on host genetics and immune–microbial interactions. Results: We discuss how genetic variation in innate and adaptive immune pathways, inflammatory signaling, and mucosal barrier function may shape host responses to microbial communities, thereby influencing susceptibility to PL. In addition, we highlight emerging data on microbiome-driven regulation of gene expression and epigenetic modifications in the endometrium and decidua, emphasizing the role of microbial metabolites in immune tolerance and placental function. Conclusions: By integrating findings from microbiome research, host genomics, immunology, and epigenetics, this review proposes a framework in which miscarriage is viewed as a consequence of disrupted host–microbe crosstalk rather than isolated pathology. Finally, we address key methodological challenges and outline future research directions aimed at advancing mechanistic understanding and translational applications. Full article

Background: Microplastics and nanoplastics, as pervasive and persistent environmental pollutants, are raising growing concerns regarding their potential risks to reproductive health, particularly pregnancy outcomes. Although the reproductive toxicity of polystyrene nanoplastics (PS-NPs) has been reported, the specific mechanisms underlying their effects on placental development and offspring health following gestational exposure remain unclear. Method: This study aimed to investigate the effects of gestational exposure to PS-NPs of different sizes (50 and 200 nm) and concentrations (1, 3, and 10 mg/mL) on placental function and embryonic development in ICR mice. An exposure model was established via tail vein injection, and samples were collected on embryonic Day 14.5 (E14.5). Results: the exposed groups tended towards increased embryo weight, embryo length, and embryo head circumference. Transcriptomic analysis revealed that PS-NP exposure significantly downregulated the expression of Ndufa5 (a subunit of mitochondrial respiratory chain complex I) and mt-CO1 (a core subunit of complex IV), but upregulated the expression of the genes Cldn1 (tight junction protein) and Erbb3 (receptor tyrosine kinase) in the placenta. Differentially expressed genes were enriched primarily in pathways related to oxidative phosphorylation, the tricarboxylic acid (TCA) cycle, and ErbB signalling. Conclusions: These changes collectively led to decreased mitochondrial ATP production, increased oxidative stress in the placenta, and potentially altered placental barrier function and trophoblast cell proliferation signalling. This study reveals a novel mechanism by which PS-NPs disrupt placental development and embryonic growth through impairment of placental energy metabolic homeostasis and key signalling pathways, thus providing crucial experimental evidence for assessing the reproductive and developmental toxicity of nanoplastics. Full article

Molecular sex determination in Syrian hamsters (Mesocricetus auratus) has been limited by the incomplete annotation of Y-linked loci in currently available genome assemblies. Here, we evaluate the Y-linked gene PRSSLY, which encodes a testis-specific serine protease-like protein, as a molecular marker for genetic sexing of Syrian hamster embryonic and placental tissues. Primers flanking a conserved PRSSLY coding region produced a male-specific amplicon showing 100% concordance with results from the established KDM5C/KDM5D PCR assay in E15.5 tail biopsies. SYBR Green–based qPCR enables the accurate detection of PRSSLY, characterized by a unique melt-curve profile, exclusively in male samples, allowing for efficient and sensitive mid-throughput analysis. Application of the PRSSLY assay to 417 placental samples from 39 dams demonstrated its suitability for large-scale sex genotyping, enabling sex assignment in the majority of samples despite the intrinsic complexity of placental tissue containing both maternal and embryonic genetic material. This assay provides a robust and reproducible approach for accurate sex genotyping in developmental and reproductive studies using Syrian hamsters. Full article

Precise postimplantation regulation of placental development with trophoblast invasion of uterine spiral arteries and the generation of low-resistance circulation within the utero-fetal unit are crucial for the further development of pregnancy. Cytokines, including chemokines, are crucial for ensuring placental function throughout pregnancy. The CX3CL1 chemokine (fractalkine), occurring in its membrane-bound form and as a soluble chemokine (sCX3CL1), acts on its sole receptor, namely, CX3CR1, creating a signaling axis that orchestrates the balance of cellular interactions, immune responses, and tissue remodeling needed at every stage of a healthy pregnancy. CX3CL1/CX3CR1 signaling is characterized by the activation of several downstream signaling cascades that interact with numerous pathways, coordinate with other receptors and modulate the expression of relevant genes. This review presents the current state of knowledge regarding the role of CX3CL1 and its interaction with CX3CR1 in establishing placental homeostasis during placentation, and it discusses the contribution of disturbances in this interaction to placental dysfunction. These disturbances are part of the pathomechanisms of specific pregnancy complications, including preeclampsia (PE) and diabetes. The potential to target the CX3CL1/CX3CR1 axis via therapeutic intervention at the level of the placenta in PE- and diabetes-complicated pregnancy is the subject of ongoing research. Full article

Porcine circovirus type 2 (PCV2), a widely distributed immunosuppressive virus, causes substantial economic losses in the global swine industry. C1QTNF6 has emerged as a novel immunoregulatory factor attracting increasing research interest due to its dual roles in both pro-inflammatory and antiviral immune responses. However, the role of C1QTNF6 in regulating PCV2 replication remains poorly characterized. Here, we analyzed C1QTNF6 expression patterns and identified its highly specific expression in placental tissues in both humans and pigs. We then overexpressed C1QTNF6 and conducted RNA sequencing analysis. Remarkably, 68 upregulated genes were identified, and most of them were interferon-stimulated genes (ISGs), including MX2 and ISG15. Functional enrichment analysis revealed that these genes were primarily associated with defense response to viruses and antiviral innate immune response. Subsequently, experimental data show that PCV2 infection significantly suppressed inflammatory responses and markedly downregulated the expression of C1qtnf6, MX2, and IFIT2. Moreover, experimental data indicated that C1QTNF6 inhibits PCV2 replication by targeting ISGs, while restoring MX2 expression. To verify whether C1QTNF6-MX2 antiviral axis mediates this antiviral effect, we constructed an MX2 overexpression plasmid and demonstrated that MX2 overexpression indeed significantly suppressed PCV2 replication. Together, these results provide important insights into PCV2-host interactions and the development of novel antiviral strategies. Full article

This study investigated the influence of maternal nutrient restriction and dietary melatonin supplementation on DNA methylation and gene expression in bovine placental cotyledons, with a focus on sex-specific changes. On day 160 of gestation, 29 Brangus heifers (bred to a single sire by AI) were subjected to a 2 × 2 factorial design: adequately fed (ADQ-CON, n = 7), nutrient-restricted (RES-CON, n = 7), and adequately fed or nutrient-restricted supplemented with 20 mg/d of melatonin (ADQ-MEL, n = 7; RES-MEL, n = 8). Cotyledons were collected at day 240 from 12 female and 17 male conceptuses for Methyl MiniSeq-GWBS and RNA-Seq. In RES-CON vs. ADQ-CON, 93 hypomethylated and 143 hypermethylated DMRs were identified, primarily in exonic, intronic, and promoter regions. Melatonin altered the methylation patterns of male and female cotyledons, respectively, with 203 and 460 DMRs associated with axon guidance, RHOC GTPase cycle, and BDNF signaling pathways. RES-MEL showed higher expression of the UBOX5 gene compared with RES-CON. Moreover, 15 DEGs (5 upregulated and 10 downregulated) were observed in the male vs. female comparison. In melatonin-treated males, PIGX, ATP11C, snoRNA U2-19, ZNF82 genes were upregulated. Thus, melatonin may modulate conceptus growth and development in a sex-specific manner. Full article

Serine protease inhibitor A3 (SERPINA3), also called α-1-antichymotrypsin, is a serine protease involved in placental dysfunction. This study examines SERPINA3 polymorphisms and haplotypes for associations with maternal hypertensive disorders of pregnancy (HDPs) and preeclampsia with severe features (sPE) or Hemolysis, Elevated Liver Enzymes, and Low Platelet (HELLP) syndrome in mother–baby dyads (HDP) and mother–father–baby triads (sPE/HELLP). This retrospective case–control study examined two patient cohorts, HDPs and severe PE/HELLP syndrome. The HDP population included cases (n = 142) and controls (n = 168) of mother–baby dyads recruited from a large, urban, safety-net hospital in Los Angeles. The sPE/HELLP syndrome population included cases (n = 189) and controls (n = 28) of mother–father–baby triads recruited through HELLP syndrome research websites. Cases were verified by medical chart abstraction when possible. Two SERPINA3 SNPs, rs4934 and rs1884082, were genotyped from saliva samples, mouthwash, or buccal swabs. The Haplin package in R was used to perform genetic association analyses. No evidence of increased risk related to individual SERPINA3 SNPs or haplotypes for the developing HDPs or sPE/HELLP was found in individual nor combined cohorts. In the HDP cohort, the g-a haplotype (relative to T-G haplotype) was borderline significant for increased risk of HDPs when carried by the child (double dose: RR = 1.58, 95% CI: (1.00, 2.52), p = 0.05). We observed significant parent-of-origin (PoO) effects in the combined cohort: specifically, an increased risk of HDPs/sPE/HELLP if the mother carries a double copy for both rs4934 (RR = 3.03, 95% CI (1.50, 6.09), p < 0.01) and rs1884082 (RR = 2.38, 95% CI (1.22, 4.71), p = 0.01). A reduced risk of HDPs/sPE/HELLP was observed for rs4934 (RR = 0.54, 95% CI (0.31, 0.98), p = 0.04) and rs1884082 (RR = 0.52, 95% CI (0.30, 0.91), p = 0.02) with child carriage of the maternally inherited allele. In contrast, child carriage of a paternally inherited copy of the variant allele for rs4934 increased risk of HDPs/sPE/HELLP (RR = 1.54, 95% CI (1.09, 2.20), p = 0.02). There was no evidence that SERPINA3 gene polymorphisms and haplotypes were associated with risk of HDPs or sPE/HELLP. However, significant PoO effects were observed in the combined cohort analysis, with child carriage of rs4934 that is maternally inherited decreasing HDPs/sPE/HELLP risk while a paternally inherited copy increases risk, suggesting a role for maternal–fetal genomic incompatibility. Full article

Preeclampsia (PE) is a complex hypertensive disorder of pregnancy characterized by new-onset hypertension and proteinuria after 20 weeks of gestation. It is classified into early-onset (EOPE, <34 weeks) and late-onset (LOPE, ≥34 weeks) subtypes, which differ in their pathophysiology, clinical course, and maternal and neonatal outcomes. EOPE arises from abnormal placentation with inadequate spiral artery remodeling and impaired uteroplacental perfusion, whereas LOPE is mainly related to maternal cardiovascular and metabolic predisposition. This review integrates current molecular, immunological, and hemodynamic evidence distinguishing EOPE from LOPE, emphasizing recent insights into angiogenic imbalance (VEGF, PlGF, sFlt-1), oxidative stress, and immune modulation. It also summarizes evolving diagnostic and prognostic biomarkers and evaluates emerging therapeutic approaches, including gene therapy targeting placental dysfunction. By comparing mechanistic pathways and clinical implications, this review highlights how gestational age–specific pathogenesis may inform risk stratification, early detection, and precision-based management of PE. Full article