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Placental development involves coordinated expansion and differentiation of trophoblast cell lineages possessing specialized functions. Among the differentiated trophoblast cell lineages are invasive trophoblast cells, which exit the placenta and invade the uterus, where they restructure the uterine parenchyma and facilitate remodeling of uterine spiral arteries. The rat exhibits deep intrauterine trophoblast cell invasion, a feature shared with human placentation, and is also amenable to gene manipulation using genome-editing techniques. In this investigation, we generated a conditional rat model targeting the invasive trophoblast cell lineage. Prolactin family 7, subfamily b, member 1 (Prl7b1) is uniquely and abundantly expressed in the rat invasive trophoblast cell lineage. Disruption of Prl7b1 did not adversely affect placental development. We demonstrated that the Prl7b1 locus could be effectively used to drive the expression of Cre recombinase in invasive trophoblast cells. Our rat model represents a new tool for investigating candidate genes contributing to the regulation of invasive trophoblast cells and their roles in trophoblast-guided uterine spiral artery remodeling., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2024. Published by The Company of Biologists Ltd.)

The invasive trophoblast cell lineages in rat and human share crucial responsibilities in establishing the uterine-placental interface of the hemochorial placenta. These observations have led to the rat becoming an especially useful animal model for studying hemochorial placentation. However, our understanding of similarities or differences between regulatory mechanisms governing rat and human invasive trophoblast cell populations is limited. In this study, we generated single-nucleus ATAC-seq data from gestation day 15.5 and 19.5 rat uterine-placental interface tissues, and integrated the data with single-cell RNA-seq data generated at the same stages. We determined the chromatin accessibility profiles of invasive trophoblast, natural killer, macrophage, endothelial and smooth muscle cells, and compared invasive trophoblast chromatin accessibility with extravillous trophoblast cell accessibility. In comparing chromatin accessibility profiles between species, we found similarities in patterns of gene regulation and groups of motifs enriched in accessible regions. Finally, we identified a conserved gene regulatory network in invasive trophoblast cells. Our data, findings and analysis will facilitate future studies investigating regulatory mechanisms essential for the invasive trophoblast cell lineage., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2023. Published by The Company of Biologists Ltd.)

The assay for transposase-accessible chromatin with sequencing (ATAC-seq) is a common assay to identify chromatin accessible regions by using a Tn5 transposase that can access, cut, and ligate adapters to DNA fragments for subsequent amplification and sequencing. These sequenced regions are quantified and tested for enrichment in a process referred to as "peak calling." Most unsupervised peak calling methods are based on simple statistical models and suffer from elevated false positive rates. Newly developed supervised deep learning methods can be successful, but they rely on high quality labeled data for training, which can be difficult to obtain. Moreover, though biological replicates are recognized to be important, there are no established approaches for using replicates in the deep learning tools, and the approaches available for traditional methods either cannot be applied to ATAC-seq, where control samples may be unavailable, or are post hoc and do not capitalize on potentially complex, but reproducible signal in the read enrichment data. Here, we propose a novel peak caller that uses unsupervised contrastive learning to extract shared signals from multiple replicates. Raw coverage data are encoded to obtain low-dimensional embeddings and optimized to minimize a contrastive loss over biological replicates. These embeddings are passed to another contrastive loss for learning and predicting peaks and decoded to denoised data under an autoencoder loss. We compared our replicative contrastive learner (RCL) method with other existing methods on ATAC-seq data, using annotations from ChromHMM genomic labels and transcription factor ChIP-seq as noisy truth. RCL consistently achieved the best performance., (© 2023 Vu et al.; Published by Cold Spring Harbor Laboratory Press.)

The hemochorial placentation site is characterized by a dynamic interplay between trophoblast cells and maternal cells. These cells cooperate to establish an interface required for nutrient delivery to promote fetal growth. In the human, trophoblast cells penetrate deep into the uterus. This is not a consistent feature of hemochorial placentation and has hindered the establishment of suitable animal models. The rat represents an intriguing model for investigating hemochorial placentation with deep trophoblast cell invasion. In this study, we used single-cell RNA sequencing to characterize the transcriptome of the invasive trophoblast cell lineage, as well as other cell populations within the rat uterine-placental interface during early (gestation day [gd] 15.5) and late (gd 19.5) stages of intrauterine trophoblast cell invasion. We identified a robust set of transcripts that define invasive trophoblast cells, as well as transcripts that distinguished endothelial, smooth muscle, natural killer, and macrophage cells. Invasive trophoblast, immune, and endothelial cell populations exhibited distinct spatial relationships within the uterine-placental interface. Furthermore, the maturation stage of invasive trophoblast cell development could be determined by assessing gestation stage-dependent changes in transcript expression. Finally, and most importantly, expression of a prominent subset of rat invasive trophoblast cell transcripts is conserved in the invasive extravillous trophoblast cell lineage of the human placenta. These findings provide foundational data to identify and interrogate key conserved regulatory mechanisms essential for the development and function of an important compartment within the hemochorial placentation site that is essential for a healthy pregnancy.

The observation that trophoblast (TB) can be generated from primed pluripotent stem cells (PSCs) by exposure to bone morphogenetic protein-4 (BMP4) when FGF2 and ACTIVIN signaling is minimized has recently been challenged with the suggestion that the procedure instead produces amnion. Here, by analyzing transcriptome data from multiple sources, including bulk and single-cell data, we show that the BMP4 procedure generates bona fide TB with similarities to both placental villous TB and TB generated from TB stem cells. The analyses also suggest that the transcriptomic signatures between embryonic amnion and different forms of TB have commonalities. Our data provide justification for the continued use of TB derived from PSCs as a model for investigating placental development., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)

Objective: To compare the characteristics of rutin-loaded PLGA (poly(lactic-coglycolic acid)) nanoparticles prepared using a single emulsion evaporation method (bulk method) and a nanoprecipitation method using microfluidics., Methods: Rutin-loaded PLGA nanoparticles were produced using different methods and characterized for size, zeta potential, entrapment efficiency (EE) and drug loading (DL). A design of experiments approach was used to identify the effect of method parameters to optimize the formulation. DSC was used to investigate the solid-state characteristics of rutin and PLGA and identify any interactions in the rutin-loaded PLGA nanoparticles. The release of rutin from PLGA nanoparticles was examined in biorelevant media and phosphate buffer (PBS)., Results: The optimal formulation of rutin-loaded PLGA nanoparticles produced using a microfluidics method resulted in a higher entrapment efficiency of 34 ± 2% and a smaller size of 123 ± 4 nm compared to a bulk method (EE 27 ± 1%, size 179 ± 13 nm). The solidstate of rutin and PLGA changed from crystalline to amorphous with the preparation of rutin- loaded PLGA nanoparticles. More importantly, using microfluidics, rutin released faster from rutin-loaded PLGA nanoparticles in biorelevant media and PBS with higher burst release compared to the rutin release from the nanoparticles prepared by using the bulk method., Conclusion: Rutin can be encapsulated in nanoparticles formulated with different methods with mean sizes of less than 200 nm. Microfluidics produced more uniform rutin-loaded PLGA nanoparticles with a higher EE, DL and faster release compared to a bulk production method., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Rutin, a strong antioxidant, has been implicated in the prevention of liver inflammation. However, low solubility and permeability through the gut wall limit development of rutin as a therapeutic agent for oral administration. Phytosomes are described as lipid nanocarriers with a complexation between the phospholipid headgroups and entrapped phytochemicals. The aim of this research was to compare the structure of rutin liposomes to rutin phytosomes. FT-IR, DSC and NMR were employed to investigate the presence of any molecular interactions between the formulation components. The FT-IR spectra showed that a new -OH bond had formed in the rutin phytosomes, suggesting the formation of a molecular complex. 31 P NMR experiments revealed that the DPPC molecule is altered when formulated as liposomes but that these changes were greater for samples from the phytosome formulation. DSC data revealed that when rutin was added to DPPC there was a significant shift in the transition temperature of DPPC. Further, the shift was greater in the THF solvent used to produce phytosomes compared to CHCl 3 used to produce liposomes. 1 H NMR spectra of the phytosome samples indicated three additional peaks that were greater than in the liposome formulation. ROESY NMR spectra provided evidence supporting the interaction between rutin and DPPC in both liposomes and phytosomes. The apparent differences in molecular interaction between liposomes and phytosomes did not however impact rutin release in biorelevant media or during in vitro small intestinal lipolysis., (Copyright © 2018 Elsevier B.V. All rights reserved.)