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Salumets, A.

Publications and source records attributed to Salumets, A..

At least 19 recordsLinked to original sources

DIPLER: rapid k-mer-based locus identification

Here, we present Dipler, a two-step strategy that combines the identification of group-specific k-mers from whole-genome sequencing data with de novo assembly of PacBio reads enriched for those k-mers. Using a Gg/gg presence/absence-like model in Juglans hindsii, we recovered the structurally distinct "G" allele from PacBio reads at coverage as low as 9x. Using the exceptional GG genotype of J. regia "Sharkey" as a complementary diploid model, we further show that two divergent "G" alleles of the same locus can be resolved and assembled separately from 13x coverage. Dipler therefore provides a rapid, reference-independent framework for identifying structurally complex loci, with potential applicability across eukaryotic species.

bioinformatics↗

Pubertal maturation and chemotherapy-associated disruption of the pediatric ovary revealed by multimodal single-cell profiling

Ovarian tissue cryopreservation enables fertility preservation in females undergoing gonadotoxic therapies, restoring fertility in adults. Although offered even before puberty, the childhood ovary and its vulnerability to therapy remain poorly characterized. Here, ovarian tissue from 16 patients undergoing fertility preservation (aged 1-16 years) and 11 adult controls (aged 22-32 years) was analyzed using single-cell RNA sequencing, spatial transcriptomics, and multiplex immunostaining. In chemotherapy-naive samples, 13 somatic cell populations underwent extracellular matrix remodeling, vascular, neural, and stromal maturation during puberty, whereas changes in germline related to chromatin remodeling. Spatial transcriptomics resolved 23 clusters across, revealing distinct tissue organization and follicular niche composition between children and adults. Chemotherapy exposure depleted perifollicular and vascular cells, suppressed intercellular signaling, and dysregulated over half of puberty-associated genes, converging on stress responses and extracellular matrix remodeling, with SEPTIN7 as a potential biomarker. These findings uncover critical developmental vulnerabilities of the pediatric ovary relevant to fertility preservation.

developmental biology↗

Microbial-derived D-lactate and LPS shape growth and inflammatory signalling in endometrial glandular epithelium

The endometrium, the inner lining of the uterus, is a dynamic tissue that undergoes precise molecular and structural changes to achieve a receptive state capable of supporting embryo implantation. Although the uterine environment was long considered sterile, molecular studies have detected microbial signals and bioactive compounds that may influence endometrial function. Endometrial epithelial organoids (EEOs) provide a three-dimensional in vitro model that recapitulates the architecture, polarity, and hormonal responsiveness of native endometrial tissue. This study aimed to elucidate how bacterial-derived compounds, including D-lactate (D-lac), commonly associated with Lactobacillus communities, and lipopolysaccharides (LPS), a component of Gram-negative bacteria, affect the transcriptomic profile of the endometrial epithelium under a hormonally induced receptive state. EEOs were exposed to different concentrations of these compounds, and relative metabolic activity was monitored through resazurin-based assays, revealing no significant alterations across the conditions tested. Transcriptomics analysis of hormonally stimulated EEOs, mimicking the mid-secretory phase, revealed that D-lac modulated genes related to epithelial development, tissue remodelling and growth regulation, whereas LPS influenced genes associated with inflammatory signalling and immune response. While key markers of receptivity remained largely stable, small transcriptional changes suggest that microbial signals may modulate the functional balance of the receptive endometrium. These findings highlight a modulatory role of microbial signals on endometrial epithelial function and demonstrate that EEOs are a robust platform for exploring host-microbe interactions in the uterus, offering new insights into the mechanisms underlying uterine receptivity.

molecular biology↗

Cyclophosphamide chemotherapy induces early p53-directed cytotoxic gene expression changes in ovarian gonadotoxicity

The alkylating chemotherapeutic cyclophosphamide (CPA) is gonadotoxic, commonly resulting in depletion of ovarian primordial follicles and leading to infertility and premature menopause in female cancer patients. However, the mechanisms underlying the early stages of CPA-induced ovarian damage are unclear, limiting our ability to prevent gonadotoxicity. This study provides a comprehensive temporal exploration of the transcriptomic profiles of ex vivo intact mouse ovaries exposed to CPA. Analyses of CPA responses from 8 to 36 hours revealed an important early role of p53 signaling. Bioinformatic analyses showed early increases in expression of specific gene clusters associated with apoptosis, DNA damage responses, and cell cycling, while expression of autophagy-associated genes was decreased. Several transcription factors, including E2F family members, likely drive early apoptosis-induced damage and p53 pathway activation. These findings provide mechanistic insight into CPA-induced ovarian toxicity, providing new avenues for the development of protective interventions.

pharmacology and toxicology↗

Explainable Machine Learning for Preoperative Relapse Prediction in Molecularly Stratified Endometrial Cancer: A Single-Center Finnish Cohort Study

Relapse risk in endometrial carcinoma (EC) is strongly influenced by molecular subtype, yet current WHO/ESGO classifications rely on postoperative data, limiting their utility for preoperative decision-making. We developed and compared interpretable machine learning (ML) models to predict relapse timing (none, [≤]6 months, >6 months) using exclusively preoperative multimodal data. In a retrospective cohort of 784 EC patients, we integrated clinicopathological, molecular, immunohistochemical, and systemic biomarkers and constructed four feature strategies: (1) Traditional (clinicopathology), (2) ESGO (guideline risk groups), (3) TP53 + MMRd (high-risk biology), and (4) POLE (low-risk biology). Classifiers (Random Forest (RF), Support Vector Machine (SVM), k-Nearest Neighbors (KNN), Gradient Boosting (GBM)) were trained with leakage-safe preprocessing and in-fold resampling; performance was evaluated via area under the curve (AUC), accuracy, recall, and F1 score, and interpretability via SHapley Additive exPlanations (SHAP). The RF-based Traditional model achieved the highest overall performance (F1 = 0.895, AUC = 0.84), while the GBM-based POLE model showed superior sensitivity (F1 = 0.886, AUC = 0.842). SHAP identified ARID1A loss, elevated CA125, thrombocytosis, and p16 expression among key predictors of relapse; while overlapping high-risk features across models included advanced stage, deeper myometrial invasion, elevated CA125, and positive cytology. These biologically coherent, explainable predictions support individualized risk stratification and may enhance preoperative decision-making, particularly for aggressive histology and high-risk molecular subtypes. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=184 HEIGHT=200 SRC="FIGDIR/small/686680v1_ufig1.gif" ALT="Figure 1"> View larger version (51K): org.highwire.dtl.DTLVardef@1be31cforg.highwire.dtl.DTLVardef@1b8496dorg.highwire.dtl.DTLVardef@1dca04corg.highwire.dtl.DTLVardef@19fe6bd_HPS_FORMAT_FIGEXP M_FIG C_FIG Workflow for Machine Learning (ML)-based relapse prediction in endometrial cancer. The schematic figure outlines the study pipeline from patient inclusion to clinical application. (A) A retrospective cohort of 784 EC patients was analyzed, integrating clinical, demographic, biomarker, and molecular data into a multimodal feature set. Patients were stratified into four molecular subgroups: NSMP, p53abn, MMRd, and POLEmut. Multiple ML algorithms (Random Forest, SVM, XGBoost, k-NN) were trained to predict relapse timing. (B) Model performance was evaluated using area under the curve (AUC) and accuracy metrics, with SHapley Additive exPlanations (SHAP) analysis applied to identify key predictive features across models. (C) SHAP-based interpretation was used to support individualized relapse risk stratification, enabling potential clinical decision-making for surveillance and therapy. HighlightsO_LIPre-operative XAI models predict relapse timing in EC with an AUC of up to 0.842. C_LIO_LIThe traditional model achieves a top accuracy of 0.797 using 22 features, while POLE maximizes sensitivity at 0.886. C_LIO_LISHAP explanations identify class-specific drivers such as stage, LVSI, size, cytology, CA125, and PR. C_LIO_LIEarly Relapse is associated with burden and aggressiveness, while Late Relapse relates to the spread and size of EC, while No Relapse indicates an inverse profile. C_LIO_LITransparent outputs facilitate risk-aligned surveillance and treatment planning before surgery. C_LI

cancer biology↗

Aberrant epithelialization: A plausible factor for the development of endometrial polyps

Endometrial polyps (EPs) are localized overgrowths of endometrial glands and stroma, common in reproductive-age and postmenopausal women, and can cause abnormal uterine bleeding and infertility. Here, we investigated the cellular heterogeneity and molecular mechanisms of EPs by integrating bulk and single-cell RNA sequencing (scRNA-seq) of EPs and adjacent endometrial tissues (adENs) from 12 women. Bulk RNA-seq revealed high transcriptional similarity, with few differentially expressed genes including upregulated KMT2B and DLEC1 and downregulated COL9A1 and RAB3C. ScRNA-seq identified eight major cell clusters, such as stromal, epithelial, endothelial, immune, perivascular, macrophage, B, and ciliated cells. Pseudotime analysis showed aberrant stromal-to-epithelial transitions in EPs, marked by MECOM and EYA2 intermediate clusters, indicating incomplete epithelial maturation. These altered differentiation trajectories may disrupt perivascular and endothelial cell development, contributing to abnormal vascular remodeling in EPs, despite minimal overall transcriptomic changes compared with adENs.

molecular biology↗

Acute high-dose irradiation of human primary ovarian cells reveals a shift in transcriptomics profile and impairment in cell-cell adhesion

STUDY QUESTIONHow do human cortical (cPOCs) and medullary (mPOCs) primary ovarian cells respond to acute X-ray exposure? SUMMARY ANSWERAcute high-dose X-ray exposure causes a shift in cPOCs and mPOCs transcriptomic profiles and impairs significantly their cell-cell adhesion ability. WHAT IS KNOWN ALREADYRadiotherapy is a leading cancer treatment, due to its effectiveness in targeting malignant cells. However, it can also affect healthy cells, potentially causing organ dysfunction, among which ovaries. When targeted radiotherapy is not feasible, fertility preservation is recommended to avoid premature ovarian insufficiency. In addition, the effects of irradiation on ovarian somatic cells remain poorly understood. STUDY DESIGN, SIZE, DURATIONOvarian tissue was obtained from patients undergoing gender-affirming surgery at Karolinska University Hospital Huddinge, Sweden. The ovarian tissue was separated into cortex and medulla, then individually dissociated into single-cell suspensions using mechanical and enzymatic methods. Monolayer cultures from cPOCs and mPOCs were exposed to a single dose of 10 Gy X-ray irradiation or left unexposed as paired controls. Following irradiation, the cells were cultured at various time-points for further molecular and morphological evaluation. PARTICIPANTS/MATERIALS, SETTING, METHODSOvarian tissue from 8 patients (age 23-36 years) was used. Dissociated cPOCs and mPOCs were cultured to 80% confluence and irradiated with 10 Gy (1.33 Gy/min), with non-irradiated controls. Cellular ATP and mitochondrial activity were assessed, followed by immunofluorescence staining for canonical irradiation-induced effects in cells: DNA damage, apoptosis and cell cycle progression. Bulk RNA-sequencing was performed on controls and irradiated samples. Libraries were prepared using the Illumina Stranded mRNA Prep Ligation protocol and sequenced on Illumina NovaSeq6000 platform. Genes were considered to be differentially expressed under the cut-off of false discovery rate (FDR) < 0.05. Subsequently, affected biological pathway was predicted using all expressed genes ranked by log2 fold change again hallmark gene sets. To further investigate the potential upstream regulators, transcription factor enrichment analysis were performed based on DEGs. To assess changes at protein level, we mapped the proteomic profile using liquid chromatography-tandem mass spectrometry. Peptides were considered to be differentially expressed (DEPs) under the cut-off of p-value < 0.01. Finally, we measured the ability of cPOCs and mPOCs to form 3D aggregates after seeding irradiated and non-irradiated cells on Biosilk scaffolds. MAIN RESULTS AND THE ROLE OF CHANCEFollowing irradiation, ATP levels and mitochondrial activity in cPOCs and mPOCs were comparable to controls, indicating minimal irradiation impact on cell viability and proliferation. Immunofluorescence analysis confirmed the modulation of canonical pathways, such as DNA damage, apoptosis and cell cycle in both cPOCs and mPOCs. Transcriptomic analysis showed that cPOCs and mPOCs at 1 h post-irradiation clustered together with the related 1 h control. However, a shift in transcriptomic profile was observed after 4 h and even more after 24 h post-irradiation in both cPOCs and mPOCs. Gene set enrichment analysis (GSEA) indicated upregulation of the p53 pathway at 4 h and 24 h post-irradiation, alongside downregulation of MYC targets, E2F targets, the G2/M checkpoint and mTORC1 pathway. Gene pattern analysis showed irradiation-dependent trends related to extracellular matrix (ECM) organisation, p53-mediated apoptotic mechanisms and chromosome segregation during the 24 h period following irradiation. Additionally, transcription factor enrichment analysis based on DEGs suggested p53 and MYC as potential upstream regulators. On a proteomic level, DEPs associated with ECM organisation and cytoskeleton formation were detected at 4 and 24 h post-irradiation. Finally, X-ray exposure hindered the cell-cell adhesion ability of both cPOCs and mPOCs, leading to impaired formation of Silk-Ovarioids. LARGE SCALE DATAThe RNA sequencing count matrix is deposited in Gene Expression Omnibus (GEO) with accession number GSE291604. The mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium via the PRIDE partner repository with the dataset identifier PXD061796. The code used for the analysis can be found at https://github.com/tialiv/X-Ovary. LIMITATIONS, REASONS FOR CAUTIONThe ovarian tissue was obtained from gender-affirming surgery patients who received androgen treatment before removal. Even though unlikely, this hormonal treatment might influence ovarian environment and alter cellular response to irradiation. Additionally, in this study the impact of X-ray exposure was assessed on a monolayer cell model, thus limiting the extrapolation power of our results to ovary in vivo. Lastly, the impact of irradiation was focused on the somatic cell populations that are essential for ovarian function. Further studies are needed to investigate the effects of X-ray exposure on ovarian follicles and their function. WIDER IMPLICATIONS OF THE FINDINGSUnderstanding the roles of MYC, p53 and cell adhesion factors in response to irradiation could guide the development of future ovarian protective strategies. These findings lay the foundation for further studies on ovarian tissue protection and fertility preservation in cancer patients. STUDY FUNDING/COMPETING INTEREST(S)This work was funded by the European Unions HORIZON 2020 research and innovation programme (MATER) under the Marie Skodowska-Curie Actions (grant agreement No: 813707), the Estonian Research Council (grants PRG1076 and PSG608), the Orion Research Foundation sr personal grant, the Research grant from the Center for Innovative Medicine (CIMED) and the Karolinska Institutet Consolidator Grant.

cell biology↗

Comprehensive 16S rRNA gene sequencing and meta-transcriptomic analyses in female reproductive tract microbiota: Two molecular profiles with different messages

In recent years, high-throughput sequencing technologies have revolutionised reproductive microbiome research. Our understanding of the endometrial microbiome is primarily based on DNA-based 16S rRNA gene profiling, but DNA detection does not imply alive microbe presence. While this method is cost-effective and widely used, it has notable limitations, including the underestimation of microbial diversity, abundance, and functionality, as well as limited species-level resolution. Meta-transcriptomic analysis, an RNA-based approach, addresses these shortcomings by capturing functional transcripts that are actively expressed in living microbes. This study aims to characterize the endometrial microbiota through a dual approach, by integrating 16S rRNA gene sequencing and meta-transcriptomic analyses. By simultaneously analysing microbial composition and gene expression within the female reproductive tract samples, we seek to provide a more comprehensive understanding of its microbiota and their functional potential. A total of 49 women, aged 27-42 years, were enrolled in the study. Vaginal swabs, endometrial brushings, and endometrial biopsy samples were collected from each participant during the mid-secretory menstrual cycle phase, 6-9 days post luteinizing hormone surge. Our findings suggest that in low-microbial-biomass environments like the endometrium, the correlation between 16S rRNA gene sequencing and meta-transcriptomics is relatively weak. This highlights the limitations of microbial analysis of low-microbial-biomass samples. Alternatively, it suggests that microbial functions and genome activity are tissue-specific and dependent on the host tissue environment. Moreover, RNA-based analysis provides higher resolution in detecting certain pathogens, even within the endometrium. In conclusion, our study underscores the need to integrate genomic and transcriptomic data in microbiota studies to better elucidate critical and health-related microbiota-host interactions.

genomics↗

OncoProExp: An Interactive Shiny Web Application for Comprehensive Cancer Proteomics and Phosphoproteomics Analysis

Cancer research has been revolutionized by mass spectrometry (MS)-based proteomics, enabling large-scale profiling of proteins and post-translational modifications (PTMs) to identify critical alterations in cancer signaling pathways. However, the lack of comprehensive, userfriendly platforms for integrative analysis limits efficient data exploration, biomarker identification, and translational insights. To address this gap, we developed OncoProExp, a Shiny-based interactive web application designed for in-depth exploration of cancer proteomes and phosphoproteomes. OncoProExp offers robust workflows for data preprocessing, including missing value imputation and statistical filtering. The platform features interactive visualizations such as principal component analysis (PCA), hierarchical clustering heatmaps, and gene set enrichment analysis (GSEA), enabling detailed functional annotation. Differential expression analysis to identify differentially expressed proteins (DEPs) and phosphoproteins (DEPPs) facilitating the discovery of potential biomarkers and therapeutic targets. The application supports survival analysis and pan-cancer exploration using clinical and proteome/phosphoproteomic datasets. OncoProExp incorporates state-of-the-art predictive modeling using machine learning algorithms, including Support Vector Machines (SVMs), Random Forests, and Artificial Neural Networks (ANNs) for cancer risk stratification, achieving near-perfect accuracy in multi-cancer and single-cancer classification. These models are enhanced by SHapley Additive exPlanations (SHAP) for interpretability. To enhance its translational utility, the platform supports user-uploaded data and enables protein-protein interaction analysis, pathway enrichment analysis, cancer drug relevance evaluation, and clinical annotation using curated cancer-specific datasets. OncoProExp is deployable via Docker containers, ensuring flexible and scalable integration into individual servers. Its utility has been demonstrated using Clinical Proteomic Tumor Analysis Consortium (CPTAC) datasets, showcasing its potential to advance cancer biomarker discovery, risk stratification, therapeutic target identification, and personalized treatment strategies. OncoProExp is freely accessible at https://oncopro.cs.ut.ee/ without login requirements, offering a comprehensive resource for translational cancer research.

bioinformatics↗

Oxygen level alters energy metabolism in bovine preimplantation embryos

STUDY QUESTIONWhat is the effect of different oxygen (O2) levels on the transcriptomic profile of bovine embryos during the in vitro culture? SUMMARY ANSWEREmbryos grown in hypoxia (6% O2) from zygotes until the blastocyst stage had the highest blastocyst formation rate, whereas normoxia (20% O2) delayed transcriptomic reprogramming and embryonic genome activation, and induced changes in energy metabolism gene expression. WHAT IS KNOWN ALREADYMammalian preimplantation embryo development is a complex sequence of events where, within a week, the zygote is reprogrammed to totipotency and subsequently diverges to embryonic and extraembryonic cell lineages for post-implantation embryo development. This period of development is sensitive to oxygen levels that can affect various cellular processes. STUDY DESIGN, SIZE, DURATIONIn this study, we used triplicate bovine embryos as a model for human embryogenesis to compare the influence of O2 levels on preimplantation embryonic development by culturing embryos either in normoxic (20% O2) or physiological hypoxic (6% O2) conditions, or sequential hypoxia until 16-cell stage and then switching to ultrahypoxic culture (2% O2). PARTICIPANTS/MATERIALS, SETTING, METHODSAs the readout for varied O2 effects, we performed RNA sequencing using 5 targeted STRT-N method on single embryos. We compared zygotes, 4-, 8-, 16-cell and blastocyst stage embryos grown in either normoxic or hypoxic condition, adding ultrahypoxia for blastocyst stage embryos as the third condition. MAIN RESULTS AND THE ROLE OF CHANCEWe found that the initial cleavage rate was not affected by O2 levels but there was a clear difference in blastocyst formation rate. In hypoxia, 36% of embryos reached blastocyst stage while in normoxia the blastocyst formation rate was 13%. In final ultrahypoxia condition only 4.6% of embryos reached blastocyst stage. Transcriptomic profiles showed that normoxic conditions slowed down oocyte transcript degradation and embryonic genome activation. Key metabolic enzyme genes were also altered between hypoxic and normoxic conditions at the blastocyst stage. Both hypoxic and ultrahypoxic conditions induced energy production by upregulating genes involved in glycolysis and lipid metabolism typical to in vivo embryos. In contrast, normoxic conditions failed to upregulate glycolysis genes and only depended on primitive oxidative phosphorylation metabolism. We conclude that constant hypoxia culture of in vitro embryos provided the highest blastocyst formation rate and appropriate energy metabolism. Normoxia altered the energy metabolism and decreased the blastocyst formation rate. Even though ultrahypoxia at blastocyst stage resulted in a drop of blastocyst formation, the transcriptional profile of surviving embryos was normal. LARGE SCALE DATAThe raw data (BCL files) are available at Zenodo: XXXXX FASTQ files generated are available in the EMBLs European Bioinformatics Institute (EMBL-EBI)-BioStudies with accession number X-XXXX. LIMITATIONS, REASONS FOR CAUTIONThe limitation of this study is the use of bovine as an animal model instead of human embryos. Due to this, the direct translation of the results to human should be taken with caution. WIDER IMPLICATIONS OF THE FINDINGSThis study supports previous literature on hypoxic culture conditions being the most suitable for in vitro embryo culture. In addition, we provide new insights on why embryos grown in normoxia do not have the same success rate as embryos grown in hypoxia. We did not observe any benefits of lowering the oxygen levels to 2%, calling for caution of switching to this culture system. STUDY FUNDING/COMPETING INTEREST(S)This project has received funding from the European Unions Horizon 2020 Research and Innovation Programme under the Marie Sklodowska-Curie grant agreement No. 813707.; Work in the JK laboratory is supported by Jane and Aatos Erkko Foundation, Sigrid Juselius Foundation, Liv och Halsa (Finland), Swedish Brain Foundation and Swedish Research Council. The study was also supported by the Estonian Research Council (grant no. PRG1076) and the Horizon Europe NESTOR project (grant no. 101120075). What this means for patients?During assisted reproduction treatment (ART) oocytes are fertilized in vitro by sperm to form an embryo. The embryos are then exposed to environmental effects during the 5 days of culture before implantation. Embryo culture takes place inside the incubator, where different oxygen levels can be used. In this study, we compared 3 different oxygen concentrations for embryo culture: atmospheric or normoxia (20%), physiologic or hypoxia (6%) and combined low and ultra-low concentration with initial culture at 6% oxygen until day 3 followed by 2% (ultrahypoxia) until day 5 of culture. We conducted this study because many ART clinics use different oxygen concentrations for embryo culture, and we aimed to provide insight on how these different concentrations impact embryo development by monitoring gene expression. As using human embryos for this type of experiments is not commonly approved, we used bovine embryos whose early development resembles that of humans. We found that culturing embryos for 5 days at constant low oxygen concentration (hypoxia) gives the highest number of embryos that reach the blastocyst stage (day 5) and have expected gene expression that provides the physiological path of embryo development. Culturing embryos at atmospheric oxygen concentration showed that only 13% of fertilised eggs reached the blastocyst stage at day 5, while culturing at the final ultra-low oxygen concentration had the lowest percentage of matured embryos, and we did not observe any benefits that would justify the use of such a culture system. We suggest that in vitro culturing of embryos at constant 5-6% oxygen gives the best results.

developmental biology↗

Silk-Ovarioids: Establishment and characterization of human ovarian primary cells 3D-model system

In vitro models that mimic ovaries are crucial for elucidating the biological mechanisms underlying follicle activation and growth. Three-dimensional (3D) systems are particularly relevant because they can replicate the heterogeneity and cell-cell communication between different ovarian cell types. However, complex models using human ovarian primary cells have not yet been established. In this study, we developed and characterized long-term cultured 3D models of primary ovarian somatic cells isolated from adult tissues, using Biosilk as a scaffold. We successfully established both ovarian cortex- and medulla-derived 3D systems, termed Silk-Ovarioids. The presence of key ovarian somatic cell types - including granulosa, stromal, endothelial, and perivascular cells - was confirmed by transcriptomics, proteomics, and immunostaining. Notably, Silk-Ovarioids exhibited the formation of a pro-angiogenic hypoxic core, as evidenced by the development of vessel-like structures after six weeks of culture. The Silk-Ovarioids demonstrated low intra-batch variability and long-term culture stability, underscoring their potential as a robust step towards creating a bioengineered, patient-specific artificial ovary.

cell biology↗

Honey bulk DNA metagenomic analysis to identify honey biological composition and monitor honeybee pathogens

Honeys DNA mixture originates from various organismal groups like plants, arthropods, fungi, bacteria, and viruses. Conventional methods like melissopalynological analysis and targeted honey DNA metabarcoding offer a limited view of honeys biological composition. We conducted a honey bulk DNA metagenomic analysis to characterize the honeys taxonomic composition and identify honey bee-related pathogens and parasites based on 266 Estonian and 103 foreign honey samples. 70.4% of the DNA in Estonian honey was derived from green plant families like Brassicaceae, Rosaceae, Fabaceae, and Pinaceae. Geographical distribution analysis revealed distinct botanical compositions between Estonian mainland and island samples. The bacterial family Lactobacillaceae was prevalent overall, reflecting the honey bee microbiota in honey. We detected 12 honey bee pathogens and parasites, including Paenibacillus larvae and Nosema ceranae. In conclusion, the study underscores the potential of bulk DNA-based and non-targeted metagenomic approaches for monitoring honey bee health, environmental quality, and honey composition, origin, and authenticity.

genomics↗

Phthalate monoesters affect membrane fluidity and cell-cell contacts in endometrial stromal cell lines

Phthalate monoesters have been identified as endocrine disruptors in a variety of models, yet understanding of their exact mechanisms of action and molecular targets in cells remains incomplete. Here, we set to determine whether epidemiologically relevant mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) can affect biological processes by altering cell plasma membrane fluidity or formation of cell-cell contacts. As a model system, we chose endometrial stromal cell lines, one of which was previously used in a transcriptomic study with MEHHP or MEHHP-containing mixtures. A short-term exposure (1 h) of membrane preparations to endocrine disruptors was sufficient to induce changes in membrane fluidity/rigidity, whereas different mixtures showed different effects at various depths of the bilayer. A longer exposure (96 h) affected the ability of cells to form spheroids and highlighted issues with membrane integrity in loosely assembled spheroids. Finally, in spheroids assembled from T-HESC cells, MEHHP interfered with the formation of tight junctions as indicated by the immunostaining of zonula occludens 1 protein. Overall, this study emphasized the need to consider plasma membrane, membrane-bound organelles, and secretory vesicles as possible biological targets of endocrine disruptors and offered an explanation for a multitude of endocrine disruptor roles documented earlier.

pharmacology and toxicology↗

Endometriotic lesions exhibit distinct metabolic signature compared to paired eutopic endometrium at the single-cell level

Current therapeutics of endometriosis are limited to hormonal action on endometriotic lesions to disrupt their growth. Based on the recent findings of the high utilization of glycolysis over oxidative metabolism (Warburg-like effect) in endometriotic lesions, a new strategy of nonhormonal management by addressing cellular metabolism has been proposed. However, it remains unclear which cell types are metabolically altered and contribute to endometriotic lesion growth for targeting them with metabolic drugs. Using single-cell RNA-sequencing, we investigated the activity of twelve metabolic pathways and genes involved in steroidogenesis in paired samples of eutopic endometrium (EuE) and peritoneal lesions (ectopic endometrium, EcE) from women with confirmed endometriosis. We detected nine major cell clusters in both EuE and EcE. The metabolic pathways were differentially regulated in perivascular, stromal and to a lesser extent in endothelial cell clusters, with the highest changes in AMP-activated protein kinase signaling, Hypoxia-Inducible Factor-1 signaling, glutathione metabolism, oxidative phosphorylation, and glycolysis/gluconeogenesis. We identified a transcriptomic co-activation of glycolysis and oxidative metabolism in perivascular and stromal cells of EcE compared with EuE, suggesting that metabolic reprogramming may play a critical role in maintaining cell growth and survival of endometriotic lesions. Additionally, progesterone receptor was significantly downregulated in perivascular and endothelial cells of EcE. The expression of estrogen receptor 1 was significantly reduced in perivascular, stromal and endothelial cells of EcE. In parallel, perivascular cells exhibited a high expression of estrogen receptor 2 and HSD17B8 gene that encodes for protein converting estrone (E1) to estradiol (E2), while in endothelial cells HSD17B2 gene coding for enzyme converting E2 to E1 was downregulated. Overall, our results identified different expression patterns of energy metabolic pathways and steroidogenesis-related genes in perivascular, stromal, and endothelial cells in EcE compared with EuE. Perivascular cells, known to contribute to the restoration of endometrial stroma and angiogenesis, can be a potential target for non-hormonal treatment of endometriosis.

molecular biology↗

Inhibition of epigenetic and cell cycle-related targets in glioblastoma cell lines: onametostat reduces proliferation and viability in both normoxic and hypoxic conditions

The choice of targeted therapies for treatment of glioblastoma patients is currently limited, and most glioblastoma patients die from the disease recurrence. Thus, systematic studies in simplified model systems are required to pinpoint the choice of targets for further exploration in clinical settings. Here, we report screening of 5 compounds targeting epigenetic writers or erasers and 6 compounds targeting cell cycle-regulating protein kinases against 3 glioblastoma cell lines following incubation under normoxic or hypoxic conditions. The viability assay indicated that PRMT5 inhibitor onametostat was endowed with high potency under both normoxic and hypoxic conditions in both MGMT-positive and MGMT-negative cell lines. In U-251 MG and U-87 MG cells, onametostat also affected the spheroid formation at concentrations lower than the currently used chemotherapeutic drug lomustine. Furthermore, in T98-G cell line, treatment with onametostat led to dramatic changes in the transcriptome profile by inducing the cell cycle arrest, suppressing RNA splicing, and down-regulating several major glioblastoma cell survival pathways. In this way, we confirmed that inhibition of epigenetic targets might represent a viable strategy for glioblastoma treatment even in the case of decreased chemo- and radiation sensitivity, although further studies in clinically more relevant models are required.

cancer biology↗

Graves' disease-associated TSHR gene is demethylated and expressed in human regulatory T cells

Epigenetic changes at specific genetic loci and the activation of transcriptional repressor FOXP3 are needed to establish and maintain the regulatory T cell (Treg) lineage. Here we studied the DNA methylation profiles in CD4+ CD25+ Tregs and CD4+ CD25- conventional T cells (Tconvs) from healthy individuals and identified a wide range of differentially methylated CpG sites (DMPs). Overall, Tregs had more hypomethylated DMPs and contained more CpG sites, which on the cell population level were less defined in their methylation status. We identified top hypomethylated CpGs in Tregs close to CENPM, IKZF2, and LYST and hypermethylated sites at the THEMIS, SCML4, and ADD3 genes. Among others, DMPs were enriched for the transcriptional repressor Kaiso binding motifs. Interestingly, in Tregs we found hypomethylation and increased expression of the TSHR gene, which is a risk gene for Graves disease (GD). However, subsequent DNA methylation profiling in healthy individuals and GD patients revealed only 19 DMPs and no change at the TSHR locus, indicating that Tregs in GD patients share a similar methylation pattern with healthy controls. Together, we show Treg-specific hypomethylation and expression of the TSHR gene, prompting additional scenarios to explain the genetic link and role of anti-TSHR autoantibodies in GD.

immunology↗

The mitochondrial component of human infertility- an increased mtDNA content and an excess of ultra-rare mtDNA variants in aneuploid versus euploid embryos.

Using low-coverage, whole-genome sequences of trophectoderm biopsies from 11,610 human blastocyst-stage embryos, we analyzed the relationship between chromosomal abnormalities and mitochondrial (mt) DNA dynamics. Comparing 6,208 aneuploid and 5,402 euploid embryos in cohort studies, we found that mtDNA content in aneuploid embryos was significantly higher than that in euploid embryos. This outcome was confirmed through intrafamilial analyses of embryos with matched parents and in vitro fertilization cycles, and it occurred independent of maternal age. Additional human population-based studies uncovered a higher abundance of ultra-rare mtDNA variants located in never-altered positions in the human population in aneuploid compared to euploid embryos in both cohort- and family-based analyses. This maternal age-independent association of increased mtDNA content and aneuploidy in human embryos may reflect a novel mechanism of purifying selection against potentially deleterious mtDNA variants, which arise from germline or early developmental mtDNA damaging events, that occurs in human embryos prior to implantation.

bioinformatics↗

Systematic evaluation of NIPT aneuploidy detection software tools with clinically validated NIPT samples

MotivationNon-invasive prenatal testing (NIPT) is a powerful screening method for fetal aneuploidy detection, relying on laboratory and computational analysis of cell-free DNA. Although several published computational NIPT analysis tools are available, no comprehensive and direct accuracy comparison of these tools is published. Here, we evaluate and determine the precision of five commonly used computational NIPT aneuploidy analysis tools, considering diverse sequencing depth (coverage) and fetal DNA fraction (FF) on clinically validated NIPT samples. MethodsWe evaluated computational NIPT aneuploidy analysis tools WisecondorX, NIPTeR, NIPTmer, RAPIDR, and GIPseq, on the same set of clinically validated samples, subsampled to different sequencing coverages between 1.25-20M reads per sample (RPS). These clinically validated samples consisted of 423 samples, including 19 samples with fetal chromosome 21 trisomy (T21, Down syndrome), eight trisomy 18 (T18, Edwards syndrome) and three trisomy 13 (T13, Patau syndrome) samples. For each software and sequencing coverage, we determined the number of false-negative and false-positive trisomy/euploidy calls. For a uniform trisomy detection interpretation, we defined a framework based on the percent-point function for determining the cut-off threshold for calling aneuploidy based on the sample Z-score and the reference group Z-score distribution. We also determined the effect of the naturally occurring arbitrary read placement driven uncertainty on T21 detection at very low sequencing coverage and the effect of cell-free fetal DNA fraction (FF) on the accuracy of these computational tools in the case of various sequencing coverages. ResultsThis is the first head-to-head comparison of NIPT aneuploidy detection tools for the low-coverage whole-genome sequencing approach. We determined that, with the currently available software tools, the minimum sequencing coverage with no false-negative trisomic cases was 5M RPS. Secondly, for these compared tools, the number of false-negative trisomic cases could be reduced if the trisomy call cut-off threshold considers the Z-score distribution of euploid reference samples. Thirdly, we observed that in the case of low FF, both aneuploidy Z-score and FF inference was considerably less accurate, especially in NIPT assays with 5M RPS or lower coverage. ConclusionsWe determined that all compared computational NIPT tools were affected by lower sequencing depth, resulting in systematically increasing the proportions of false-negative trisomy results as the sequencing depth decreased. Trisomy detection for lower coverage NIPT samples (e.g. 2.5M RPS) is technically possible but can increase the proportion of false-positive and false-negative trisomic cases, especially in the case of low FF.

bioinformatics↗