bims-placeb 2026-05-24 papers

bioRxiv. 2026 May 07. pii: 2026.05.04.722786. [Epub ahead of print]

Creatine kinase regulates energy metabolism and growth of trophoblasts.

Nirvay Sah, Claire Zheng, Walee Shaik, Frances H Stein, Rachana Rajupalem, Morgan Meads, Donald Pizzo, Francesca Soncin.

STUDY QUESTION: Does the human placenta utilize the creatine phosphagen system for energy homeostasis during development?
SUMMARY ANSWER: Components of the creatine (Cr)-creatine kinase (CK)-phosphocreatine (PCr) system are dynamically expressed by the trophoblast and mesenchymal compartments throughout gestation wherein creatine kinase is required for cellular ATP metabolism, cell cycle, and proliferation of trophoblast cells.
WHAT IS KNOWN ALREADY: The Cr-CK-PCr system maintains ATP homeostasis in tissues with high energy demand and is required for proliferation, migration, and invasion of tumor cells. The term human placenta can synthesize and transport creatine locally. Early placental development involves trophoblast proliferation, an event requiring ATP, but the role of the creatine phosphagen system during early placental development remains unknown.
STUDY DESIGN, SIZE, DURATION: We performed immunohistochemistry (IHC) and immunofluorescence (IF) for different components (biosynthesis, transport, utilization) of the Cr-Ck-PCr system in human placentae (n=3/group) across gestation including first trimester, second trimester, and term. Using primary human trophoblast stem cells (hTSCs) and trophoblast organoids (TO), we determined the role of the creatine phosphagen system in trophoblast growth by functional inhibition of creatine kinase.
PARTICIPANTS/MATERIALS, SETTING, METHODS: IHC/IF were performed in human placentae across gestation for proteins involved in biosynthesis (AGAT and GAMT), transport (SLC6A8, SLC22A15, and SLC6A13) and utilization (CKB and CKMT1) of creatine to determine the presence of the creatine phosphagen system locally in the placenta. For delineating the functional importance of this system in placental development, cyclocreatine (cCr), a creatine analogue, was used for functional inhibition of CK. Primary hTSCs were culture in medium containing 0 (control), 1, 10, 20 mM cCr for 48 hours followed by analysis of cell growth (cell count), cell cycle (EdU incorporation assay), apoptosis (Annexin V/PI flow cytometry), energy metabolism (Sea horse mito-stress and glycolytic stress tests), and gene expression (qPCR). Primary TO were also treated with 20mM cCr for 6 days in vitro to determine the role of Cr-CK-PCr system in placental development.
MAIN RESULTS AND THE ROLE OF CHANCE: AGAT localized to the fetal villous mesenchyme, while GAMT was broadly expressed in the trophoblast and fetal mesenchyme compartments across gestation. CKB localized primarily to fetal mesenchyme with strongest expression at term. CKMT1 was broadly expressed in all trophoblast subtypes. SLC6A8 was abundant in early syncytiotrophoblast but absent at term, where its expression shifted to fetal blood vessels. SLC22A15 was expressed in the endothelial cells of fetal capillaries across gestation. In primary hTSCs, cyclocreatine (20mM) treatment reduced proliferation (P<0.001), decreased expression of trophoblast epithelial marker EGFR (P<0.05), induced G0/G1 and G2/M arrests (P<0.0001), enhanced early and late apoptosis (P<0.0001), and downregulated GPX8 expression (P<0.05). Seahorse analysis revealed marked reductions (P<0.01) in mitochondrial (basal, maximal, and ATP-linked) and glycolytic (rate, capacity, and reserve) function compared to controls. In primary human TO, cyclocreatine treatment reduced the growth of organoids (P<0.05) as well the expression of EGFR (P<0.05).
LARGE SCALE DATA: N/A Limitations, reasons for caution: Further experiments assessing apoptosis, cellular stress and redox imbalance may provide more mechanistic role of the creatine phosphagen system in trophoblast metabolism and function. Since the functional role of the Cr-CK-PCr system was investigated in vitro, findings of this study should be taken with caution for implications of in vivo placental development. Nevertheless, reproducible results of reduced growth of trophoblast cells using both 2D and 3D cultures is highly suggestive of the importance of the creatine phosphagen system in early placental development.
WIDER IMPLICATIONS OF THE FINDINGS: This study provides foundational knowledge that the placenta contains the creatine phosphagen system, known for ATP homeostasis, and that this system ensures proper cell division, survival and placental development. Dysregulation of components of Cr-CK-PCr system in placenta has been observed in pregnancy disorders such as preeclampsia and fetal growth restriction warranting continued investigation into mechanisms and potential remediation using creatine supplementation. Stem cells share similar metabolic features so findings of this study can be implicated in other stem cells models as well.
STUDY FUNDING/COMPETING INTEREST(S): This work was supported by CIRM EDUC4-12804 Interdisciplinary Stem Cell Training Grant and a Lalor Foundation Postdoctoral Fellowship awarded to NS, and by the California Institute for Regenerative Medicine (DISC0-13757) and the National Institute of Child Health and Human Development (R01-HD096260) award to FS. The authors have no competing interest to declare.

DOI: https://doi.org/10.64898/2026.05.04.722786

Adv Exp Med Biol. 2026 ;1509 131-157

Trophoblast Fusion Deficiency in Placenta-Related Pregnancy Disorders.

Yan Xiong, Yu-Bin Ding.

Trophoblast cell fusion is a vital developmental process that enables the formation of the multinucleated syncytiotrophoblast (STB), which plays a central role in placental function and maternal-fetal exchange. Fusion defects in this lineage are closely associated with pregnancy complications such as preeclampsia (PE) and fetal growth restriction (FGR). Although the fusion of trophoblasts is a highly coordinated event, it involves multiple interdependent steps, including transcriptional programming, membrane remodeling, cytoskeletal rearrangement, metabolic adaptation, and immune regulation. Recent studies have uncovered critical molecular mediators at each of these levels. Transcription factors such as Glial cells missing transcription factor 1(GCM1), Krüppel-like factor 6(KLF6), and Transcription factor EB(TFEB) govern differentiation timing; fusion proteins, including Syncytin-1/2 and Mfn2, facilitate membrane merger; polarity regulators and actin-associated proteins like Par6 and CNN3 organize cytoskeletal architecture; metabolic reprogramming, particularly a shift from oxidative phosphorylation to glycolysis, supplies energy and biosynthetic precursors; and immune modulators such as pregnancy-induced factor 1 and Interleukin-10(IL-10) ensure a permissive environment for fusion at the maternal-fetal interface. Epigenetic mechanisms, including DNA methylation and histone modifications, further fine-tune the expression of fusion-related genes. Alongside mechanistic discoveries, a wide range of experimental models has been developed to investigate trophoblast fusion in vitro. These include traditional monolayer cell lines (e.g., BeWo), primary human trophoblasts, placental explants, trophoblast stem cells, and trophoblast organoids. Each model system provides distinct advantages in recapitulating aspects of syncytialization and placental physiology. Moreover, the integration of multi-omics technologies-such as single-cell and spatial transcriptomics, proteomics, metabolomics, and epigenomics-has expanded our understanding of the spatiotemporal dynamics and molecular complexity underlying trophoblast fusion. Despite these advances, several key challenges remain unresolved, including the lack of models that fully recapitulate the structural and functional features of the human maternal-fetal interface and the limited understanding of posttranslational and spatiotemporal regulatory mechanisms. Addressing these gaps will be essential for translating basic insights into diagnostic and therapeutic innovations for placental diseases.

Keywords: Multi-omics; Placenta; Placenta-related pregnancy disorders; Syncytiotrophoblast; Transcription factors; Trophoblast fusion

DOI: https://doi.org/10.1007/978-3-032-22637-2_6

Sci Rep. 2026 May 21.

Placental dysfunction reflects endocrine impairment and trophoblast alterations in polycystic ovarian syndrome.

Ananya Mahapatra, Gautami Pillai, Remi Rana, Zeel Shah, Laxmipriya Nampoothiri.

Polycystic ovary syndrome (PCOS) is a common endocrine disorder that contributes to pregnancy complications like Intra Uterine Growth Restriction (IUGR), leading to compromised foetal outcome. Although maternal metabolic and hormonal imbalances are well-established in PCOS, the specific molecular alterations within the placenta and its outcome remains poorly explored. This study aimed to characterize key molecular signaling alterations in PCOS placentae with respect to steroid hormone receptors, trophoblast lineage specification, along with their structural alterations. To understand the above alterations, PCOS rodent mothers were developed using letrozole treatment for 21days daily orally, following which induction of pregnancy and those pregnant animals were sacrificed at GD18. Tissues were subjected to expression levels of steroidal and placental cell markers using transcriptomic and protein expression, along with morphometric and histological analysis, correlated with hormone profile. Histological analysis of GD 18 PCOS placenta exhibited a reduction in labyrinth zone, with an increased AR expression, along with downregulation of PR, ER ɑ and ER β, indicating an altered steroidal status. Moreover, dysregulation of genes such as Phlda2, Tpbpa, Pcdh12, Prl3b1, CDX2, GCM1, and GATA2 along with reduced expression of SynA, Syn B were observed suggesting an impaired trophoblast differentiation, vascular development, and immune tolerance. Additionally, elevated expressions of Flt4, H2Kd and IFN gamma suggested compensatory mechanisms attempting to offset placental dysfunction. This study clearly indicates maternal PCOS pathophysiology effects placental development by altering the morphology, along with abnormal hormonal homeostasis, contributing to impaired differentiation. These findings underscore the importance of targeting placental pathways in the management of PCOS-related pregnancy outcomes.

Keywords: FGR; PCOS; Placenta; Steroidogenesis; Trophoblast

DOI: https://doi.org/10.1038/s41598-026-51085-x

Toxicol Sci. 2026 May 22. pii: kfag060. [Epub ahead of print]

Stress-Activated Pathways Mediate PFAS Effects on Human Placental Syncytiotrophoblast Cells.

Keisuke Kozai, Kaela M Varberg.

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental pollutants associated with placenta-mediated pregnancy complications, including preeclampsia, fetal growth restriction, and preterm birth. The syncytiotrophoblast (STB), which forms the placental barrier at the maternal-fetal interface and is directly exposed to maternal blood, is a primary site of PFAS exposure. Although PFAS induce STB apoptosis, the upstream stress-signaling pathways involved remain poorly defined. Here, we investigated stress-responsive signaling mechanisms mediating PFAS-induced STB cell death. STB differentiated from human trophoblast stem cells were exposed to vehicle or an environmentally relevant mixture of five PFAS (PFOA, PFOS, PFHxS, PFNA, and PFDA; 0.0138-34.5 µM) for 3 or 6 hours. Cytotoxicity, apoptosis, mitochondrial membrane potential, and stress-signaling pathway activation were assessed by lactate dehydrogenase release, immunoblotting, JC-10 assay, and RT-qPCR. PFAS mixtures did not induce cytotoxicity at 3 hours but significantly increased cytotoxicity at 6 hours at 34.5 µM, coinciding with induction of cleaved caspase-3, cleaved PARP, and NOXA. The pan-caspase inhibitor z-VAD-FMK prevented cytotoxicity, indicating caspase-dependent apoptosis. PFAS exposure reduced mitochondrial membrane potential and activated the integrated stress response (ISR), as evidenced by eIF2α phosphorylation, ATF4 induction, and increased ATF4 target gene expression. In parallel, c-Jun N-terminal kinase (JNK) signaling was activated, as evidenced by JNK phosphorylation and induction of immediate-early genes (JUN, FOS, EGR1). Pharmacologic inhibition of the ISR modestly attenuated PFAS-induced cytotoxicity, whereas pharmacologic inhibition of JNK rescued cytotoxicity and apoptotic signaling. Together, these findings identify JNK-driven stress signaling as the dominant mediator of PFAS-induced STB apoptosis, with a secondary contribution from the ISR.

Keywords: JNK signaling; PFAS mixtures; apoptosis; placenta; syncytiotrophoblast

DOI: https://doi.org/10.1093/toxsci/kfag060

Genome Biol Evol. 2026 May 23. pii: evag120. [Epub ahead of print]

Evolution of gene expression across functional regions of the mouse placenta.

Fernando Rodriguez-Caro, Emily C Moore, Ashlin Slanger, Jeffrey M Good.

The eutherian placenta exhibits rapid morphological evolution and is a hotspot for the emergence of reproductive incompatibilities between closely related species. These evolutionary patterns are thought to be a consequence of rapid divergence in gene expression driven by maternal-fetal conflict over resource allocation. However, it remains unclear how the diversity of placental functions shapes gene specialization and expression divergence. We generated genome-wide gene expression and DNA methylation data from fetal and maternal placental tissues of three closely related mouse lineages (Mus musculus musculus, M. m. domesticus, M. spretus) and integrated single-cell expression data to investigate how tissue specialization influences gene expression evolution in the rodent placenta. Comparisons among placental regions within M. m. musculus revealed significant differences in patterns of functional enrichment, imprinting, and X-linked expression across placental layers. The labyrinth zone, the primary site of nutrient exchange, showed strong enrichment for parent-of-origin expression of both autosomal and X-linked genes. Cross-species comparisons of gene expression within each placental layer revealed increased expression level divergence at the maternal-fetal interface. We also identified a subset of genes with maternally-biased expression that are spatially associated with the maternal-fetal interface. Parent-of-origin DNA methylation was dominated by epigenetic modification of the maternal genome and interspecific comparisons of parent-of-origin expression revealed overall conservation punctuated by changes in imprinting status of two genes. These findings unveil important links between core elements of placental biology and the evolution of placental gene expression, demonstrating how tissue specialization has influenced parent-of-origin effects and interspecific expression divergence.

Keywords: genomic imprinting; junctional zone; labyrinth zone; maternal decidua; maternal-fetal interface

DOI: https://doi.org/10.1093/gbe/evag120

Am J Reprod Immunol. 2026 May;95(5): e70258

ERα Facilitates Hypoxia-induced Ferroptosis in Placental Trophoblasts by Transcriptionally Activating ACSL4.

Xufei Fan, Yali Yang, Xiaodan Zhu, Lichao Yuan, Min Hu, Xiaoxia Bai.

PROBLEM: Preeclampsia (PE), characterized by hypertension and proteinuria, involves placental dysfunction linked to oxidative stress and ferroptosis. The role of estrogen receptor α (ERα) in hypoxia-induced trophoblast ferroptosis remains unclear.
METHOD OF STUDY: A PE rat model was established using L-NAME injection. Placental tissues were analyzed for protein expression via Western blot. In vitro, HTR-8/SVneo cells were cultured under hypoxic conditions to simulate PE-related hypoxia. ERα was knocked down using siRNAs, and acyl-CoA synthetase long-chain family member 4 (ACSL4) was overexpressed via plasmid transfection. Cell viability, apoptosis, migration, oxidative stress parameters, and ferroptosis-related indicators were assessed using CCK-8, flow cytometry, Transwell assays, and specific biochemical kits. In addition, primary syncytiotrophoblast (STB) cells were isolated from placentas of healthy and PE rats for validation experiments. The transcriptional regulation of ACSL4 by ERα was examined using dual luciferase reporter assays.
RESULTS: In PE rat placentas, ERα and ACSL4 were significantly upregulated, while GPX4 and SLC7A11 were downregulated. In addition, the lipid peroxidation products 4-HNE and MDA were significantly increased in PE placental tissues. Hypoxia induced ferroptosis in HTR-8/SVneo cells, characterized by increased Fe2 + levels, elevated 4-HNE and MDA levels, lipid peroxidation, and activation of the ERα/ACSL4 axis. Knockdown of ERα attenuated hypoxia-induced cell injury, oxidative stress, and ferroptosis, whereas ACSL4 overexpression reversed these protective effects. Furthermore, experiments in primary STB cells isolated from PE rats showed that ERα knockdown similarly alleviated ferroptosis-associated injury and suppressed ACSL4 expression. Mechanistically, ERα bound directly to the ACSL4 promoter and transcriptionally activated its expression.
CONCLUSIONS: The ERα-ACSL4 axis plays a critical role in hypoxia-induced ferroptosis in placental trophoblasts. ERα transcriptionally activates ACSL4, promoting lipid peroxidation and ferroptosis, thereby contributing to placental dysfunction in PE. These findings provide a novel theoretical basis for understanding PE pathogenesis and highlight potential therapeutic targets for intervention.

Keywords: ERα; Preeclampsia; ferroptosis; placental trophoblasts

DOI: https://doi.org/10.1111/aji.70258

Placenta. 2026 May 19. pii: S0143-4004(26)00183-9. [Epub ahead of print]181 160-167

Optoacoustic imaging reveals preserved placental oxygen saturation in a mouse model of preeclampsia.

Hélène Collinot, Thibault Wartelle, Isabelle Lagoutte, Daniel Vaiman, Gilles Renault.

INTRODUCTION: Preeclampsia is a hypertensive disorder of pregnancy associated with placental dysfunction. Optoacoustic imaging enables non-invasive, real-time assessment of placental oxygen saturation. This study aimed to evaluate placental oxygenation and its response to hypoxia in the STOX1A mouse model of preeclampsia.
METHODS: Two groups were studied: STOX1A pregnancies (wild-type females crossed with transgenic STOX1A males) and controls (wild-type crosses). Blood pressure and urinary albumin-to-creatinine ratio were monitored during gestation. Placental oxygen saturation was assessed by multispectral optoacoustic imaging between embryonic days 15.5 and 17.5 under normoxia and hypoxia. Delta oxygen saturation and desaturation kinetics were analyzed using sigmoid curve fitting.
RESULTS: Thirty-one placentas from seventeen control pregnancies and twenty-nine placentas from twenty STOX1A pregnancies were analyzed. The STOX1A group showed increased blood pressure and albuminuria compared to controls (mean systolic blood pressure change at embryonic day 17.5: +21.2 ± 11 mmHg versus -8.4 ± 3.7 mmHg, p = 0.006; albumin-to-creatinine ratio fold-change: 3.91 [2.52-17.14] versus 0.86 [0.43-2.49], p = 0.033). Placental baseline oxygen saturation was similar between groups (70.1 ± 5.3 percent versus 70.0 ± 6.9 percent, p = 0.96). No significant differences were observed in delta oxygen saturation (17.0 ± 6.9 percent versus 16.1 ± 7.1 percent, p = 0.61) or desaturation rate (8.6 ± 6.0 versus 7.9 ± 6.1, p = 0.43) during hypoxia.
DISCUSSION: Despite a confirmed preeclamptic phenotype, placental oxygenation and adaptation to maternal hypoxia were preserved in the STOX1A model, suggesting maintained placental resilience in late gestation.

Keywords: Mouse model; Optoacoustic imaging; Placental oxygenation; Preeclampsia

DOI: https://doi.org/10.1016/j.placenta.2026.05.021

iScience. 2026 Jun 19. 29(6): 115859

Vitrification-warming delays preimplantation development and impairs mitochondrial function and cytoplasmic lattices integrity in mouse embryos.

Mariana T Barroso, Jose A Rodriguez Muñoz, Viola Sjöström, Konstantina Dindini, Jian Zhao, Kenny A Rodriguez-Wallberg, Arturo Reyes Palomares.

Vitrification and warming of human embryos have become standard procedures in assisted reproduction over the past two decades. Although generally considered safe, their full impact on embryo development remains unclear. Epidemiological studies have raised concerns about differences in birth weight and long-term health outcomes between newborns from fresh versus frozen embryo transfers. Here, we present a descriptive study using mouse embryos to investigate the impact of vitrification and warming on developmental kinetics, mitochondrial function, and cytoplasmic lattice integrity. Time-lapse imaging revealed significant developmental delays across all preimplantation stages in vitrified embryos. Additionally, mitochondrial distribution, volume, and membrane potential exhibited signs of impairment. Ultrastructural analysis identified ruptured mitochondrial membranes, disrupted cytoplasmic lattices during early cell divisions, and underdeveloped mitochondrial cristae at the blastocyst stage. We hypothesize that embryo vitrification and warming disrupt mitochondrial function and compromise cytoplasmic lattices integrity, ultimately contributing to developmental delays in preimplantation mouse embryos.

Keywords: Cell biology; Cryopreservation; Developmental biology

DOI: https://doi.org/10.1016/j.isci.2026.115859

J Obstet Gynaecol Can. 2026 May 18. pii: S1701-2163(26)00198-2. [Epub ahead of print] 103396

Rethinking Preeclampsia: How Placental Growth Factor (PlGF) Is Transforming Diagnosis and Management.

John W Snelgrove.

Preeclampsia is a severe pregnancy complication affecting pregnant people, their babies, and families. It remains a leading global cause of maternal and fetal morbidity and mortality. Our understanding of this disease continues to evolve, with opportunities for improved preeclampsia prediction, diagnosis, and management. This review outlines how placental growth factor (PlGF) could help clinicians better predict, diagnose, and ultimately manage preeclampsia and its complications. The material was originally presented at the Cannell Lecture in Toronto on 29 November 2024. The Cannell Lecture is hosted annually by the Society of Obstetricians & Gynaecologists of Canada and the University of Toronto in honour of Dr. Doug Cannell, who was Chair of the Department of Obstetrics & Gynaecology from 1950-1965.

Keywords: Placental Growth Factor; Pregnancy; aspirin; pre-eclampsia

DOI: https://doi.org/10.1016/j.jogc.2026.103396

J Vis Exp. 2026 Apr 30.

Three-Dimensional Organoids Culturing and Processing Techniques for Myometrial and Uterine Fibroids Generation.

Mervat M Omran, Maria Victoria Bariani, Mohamed Ali, Ayman Al-Hendy.

Uterine fibroids are the most common benign, monoclonal, gynecological tumors in a woman's uterus. To overcome the common obstacles related to the methods used in studying these pathologies, we aimed to devise a strategy to generate three-dimensional organoid models of myometrium and uterine fibroid stem cells using collagen-containing hydrogels as embedding scaffolds. Specifically, collagen-containing hydrogels in a low attachment V-bottom 96-well plates were exploited. This method allowed the development of 3D organoids of two stem cell types from normal myometrium and uterine fibroid-containing myometrium by embedding them in collagen-containing hydrogels and forming organoids in a suitable stem cell proliferation medium. The organoids successfully differentiated, proliferated, and self-organized into complex structures, developing a sustainable system. The importance of this model is the understanding of pathophysiology and etiopathogenesis, as well as for testing new drugs to prevent or treat uterine fibroids.

DOI: https://doi.org/10.3791/67568