Search Results (1,021)

Objectives: This study investigates whether scan time in the high-resolution magnetic resonance imaging (MRI) of human embryos can be reduced without compromising spatial resolution by applying zero-shot self-supervised learning (ZS-SSL), a deep-learning-based reconstruction method. Methods: Simulations using a numerical phantom were conducted to evaluate spatial resolution across various acceleration factors (AF = 2, 4, 6, and 8) and signal-to-noise ratio (SNR) levels. Resolution was quantified using a blur-based estimation method based on the Sparrow criterion. ZS-SSL was compared to conventional compressed sensing (CS). Experimental imaging of a human embryo at Carnegie stage 21 was performed at a spatial resolution of (30 μm)³ using both retrospective and prospective undersampling at AF = 4 and 8. Results: ZS-SSL preserved spatial resolution more effectively than CS at low SNRs. At AF = 4, image quality was comparable to that of fully sampled data, while noticeable degradation occurred at AF = 8. Experimental validation confirmed these findings, with clear visualization of anatomical structures—such as the accessory nerve—at AF = 4; there was reduced structural clarity at AF = 8. Conclusions: ZS-SSL enables significant scan time reduction in high-resolution MRI of human embryos while maintaining spatial resolution at AF = 4, assuming an SNR above approximately 15. This trade-off between acceleration and image quality is particularly beneficial in studies with limited imaging time or specimen availability. The method facilitates the efficient acquisition of ultra-high-resolution data and supports future efforts to construct detailed developmental atlases. Full article

Background: Toxoplasma gondii is a globally widespread parasite responsible for toxoplasmosis, a zoonotic disease with significant impact on both human and animal health. The current lack of safe and effective treatments underscores the need for new drugs. Earlier, thiosemicarbazones (TSCs) and their metal complexes have shown promising activities against T. gondii. This study evaluated a gold (III) complex C3 and its TSC ligand C4 for safety in host immune cells and zebrafish embryos, followed by efficacy assessment in a murine model for chronic toxoplasmosis. Methods: The effects on viability and proliferation of murine splenocytes were determined using Alamar Blue assay and BrdU ELISA, and potential effects of the drugs on zebrafish (Danio rerio) embryos were detected through daily light microscopical inspection within the first 96 h of embryo development. The parasite burden in treated versus non-treated mice was measured by quantitative real-time PCR in the brain, eyes and the heart. Results: Neither compound showed immunosuppressive effects on the host immune cells but displayed dose-dependent toxicity on early zebrafish embryo development, suggesting that these compounds should not be applied in pregnant animals. In the murine model of chronic toxoplasmosis, C4 treatment significantly reduced the parasite load in the heart but not in the brain or eyes, while C3 did not have any impact on the parasite load. Conclusions: These results highlight the potential of C4 for further exploration but also the limitations of current approaches in effectively reducing parasite burden in vivo. Full article

Background/Objectives: Low folate intake before and during pregnancy increases the risk of neural tube defects and other adverse outcomes. Gene variants such as MTHFR 677C>T (rs1801133) may increase risks associated with suboptimal folate intake. Our objective was to use BALB/cJ Mthfr^677C>T mice to evaluate the effects of the TT genotype and low folate diets on embryonic development and MTHFR protein expression in pregnant mice. Methods: Female 677CC (mCC) and 677TT (mTT) mice were fed control (2 mg folic acid/kg (2D)), 1 mg folic acid/kg (1D) and 0.3 mg folic acid/kg (0.3D) diets before and during pregnancy. Embryos and maternal tissues were collected at embryonic day 10.5. Embryos were examined for developmental delays and defects. Methyltetrahydrofolate (methylTHF) and total homocysteine (tHcy) were measured in maternal plasma, and MTHFR protein expression was evaluated in maternal liver. Results: MethylTHF decreased due to the experimental diets and mTT genotype. tHcy increased due to 0.3D and mTT genotype; mTT 0.3D mice had significantly higher tHcy than the other groups. MTHFR expression was lower in mTT liver than mCC. MTHFR protein expression increased due to low folate diets in mCC mice, whereas in mTT mice, MTHFR expression increased only due to 1D. Developmental delays were increased in the litters of mTT mice fed 1D and 0.3D. Conclusions: The Mthfr^677C>T mouse models the effects of the MTHFR 677TT genotype in humans and provides a folate-responsive model for examination of the effects of folate intake and the MTHFR 677C>T variant during gestation. Full article

Triphenyl phosphate (TPhP) is a widely used organophosphate flame retardant and plasticizer, raising concerns over its health impacts. This study examined the effects of embryonic TPhP exposure on axial skeletal development and metabolism in medaka (Oryzias latipes), a vertebrate fish model relevant to human bone biology. Medaka embryos were exposed to 1 µM TPhP and assessed through early larval stages. TPhP impaired vertebral ossification, causing shortened centra and reduced cartilage in the caudal complex, alongside disrupted distribution of osteoblast-lineage cells. Key osteogenic genes were significantly downregulated at 14 days post fertilization, and transcriptomic analysis revealed altered mitochondrial pathways linked to skeletal disorders. Functionally, TPhP-exposed larvae showed reduced caudal fin regeneration and decreased metabolic rate and oxygen consumption, consistent with mitochondrial dysfunction. These findings indicate that TPhP disrupts bone development and metabolism by affecting osteoblast differentiation and mitochondrial regulation, highlighting the value of small fish models for studying environmental toxicants and bone metabolic disease risk. Full article

The adrenal medulla and organs of Zuckerkandl consist of chromaffin cells that produce, store, and secrete catecholamines. In humans, the adrenal medulla is known to function throughout postnatal life, while the organs of Zuckerkandl degenerate by 2–3 years of postnatal life. Although the history of investigation of chromaffin cells goes back more than a century, little is known about the reciprocal organogenesis of the adrenal glands and organs of Zuckerkandl during human fetal development. In the current study, we compared these two organs using serial sectioning, routine histological staining, and immunohistochemical reactions in human embryos, prefetuses, and fetuses from 8 to 26 gestational weeks. In our study, we used antibodies for tyrosine hydroxylase, dopamine beta-hydroxylase, and phenylethanolamine N-methyltransferase, which are enzymes of catecholamine synthesis, β-III tubulin, and S100. We found two morphological cell types (large and small) in the developing ganglia, organs of Zuckerkandl, and adrenal medulla, and two migration patterns of large cells and small cells. The immunohistochemical characteristics of these cells were determined. We revealed that the number of small cells increased significantly at the ages from 16 to 21–22 gestational weeks, followed by a decrease at 22.5–26 gestational weeks. The presence of two large cell subpopulations was suggested—those that migrate primarily from organs of the Zuckerkandl region and those that differentiate later from the small cells. We also determined that 12 gestational weeks was the age of the first appearance of phenylethanolamine N-methyltransferase reactivity in developing chromaffin cells, temporally correlating with synaptogenesis events. This is important data in the light of the controversial glucocorticoid theory of phenylethanolamine N-methyltransferase induction in humans. Full article

Zebrafish are model organisms for drug screening owing to their transparent bodies, rapid embryonic development, and genetic similarities with humans. However, using standard polystyrene culture plates can limit the oxygen supply, potentially affecting embryo survival and the reliability of assays conducted in zebrafish. In this study, we evaluated the application of a novel, highly oxygen-permeable culture plate (InnoCell^TM) in zebrafish development and drug screening assays. Under both normal and oxygen-restricted conditions, zebrafish embryos cultured on InnoCell^TM plates exhibited significantly improved developmental parameters, including heart rate and body length, compared with those cultured on conventional polystyrene plates. The InnoCell^TM plate enabled a significant reduction in medium volume without compromising zebrafish embryo viability, thereby demonstrating its advantages, particularly in high-throughput 384-well formats. Drug screening tests using antiangiogenic receptor tyrosine kinase inhibitors (TKIs) revealed enhanced sensitivity and more pronounced biological effects in InnoCell^TM plates, as evidenced by the quantification of intersegmental blood vessels and gene expression analysis of the vascular endothelial growth factor receptor (vegfr, also known as kdrl). These results indicate that the InnoCell^TM highly oxygen-permeable plate markedly improves zebrafish-based drug screening efficiency and assay reliability, highlighting its potential for widespread application in biomedical research. Full article

Tissue remodeling of human endometrium occurs during the menstrual cycle to prepare for embryo adhesion and invasion. The ovarian steroid hormones 17β-estradiol and progesterone control the menstrual cycle to achieve the receptive state during the “window of implantation” (WOI). Here, we focus on the human endometrial epithelium and its changes in polarity, adhesion, cytoskeletal organization and the underlying extracellular matrix enabling embryo implantation. The adhesion and invasion of the trophoblast via the apical plasma membrane of epithelial cells is a unique cell biological process, which is coupled to partial epithelial–mesenchymal transition (EMT). Given the fundamental species differences during implantation, we restrict the review mainly to the human situation and focus on cell culture systems to study the interaction between human trophoblast and endometrial cells. We summarize current knowledge based on the relatively scarce in vivo data and the steadily growing in vitro observations using various cell culture systems. Full article

Species have different strategies for implantation and placentation. Much can be learned about general molecular and cellular biology through the examination and comparison of these differences. To varying degrees, implantation in all species includes alterations in epithelial polarity, the transformation of the endometrial stroma, the differentiation of the trophoblast, cell-to-cell and tissue-to-tissue signaling through hormones, cytokines, and extracellular vesicles, and the alteration of the maternal immune system. This review focuses on implantation in pigs, sheep, and cows. These species share with mice/rats and humans/primates the key events of early embryonic development, pregnancy recognition, and the establishment of functional placentation. However, there are differences between the pregnancies of livestock and other species that make livestock unique biomedical models for the study of pregnancy and cell biology in general. Pig, sheep, and cow conceptuses (embryo/fetus and associated placental membranes) elongate prior to implantation, displaying central implantation, extended periods of conceptus attachment to the uterus, and epitheliochorial (pigs) and synepitheliochorial (sheep and cows) placentation. This review will discuss what is understood about how the trophoblast and extraembryonic endoderm of pig, sheep, and cow conceptuses elongate, and how a major goal of current in vitro models is to achieve conceptus elongation. It will then examine the adhesion cascade for conceptus implantation that initiates early placental development in pigs, sheep, and cows. Finally, it will conclude with a brief overview of early placental development in pigs, sheep, and cows, with a listing of some important “omics” studies that have been published. Full article

The ability to model the earliest stages of human embryonic development in vitro using pluripotent stem cells offers researchers new ways to understand and interrogate the intricacies of implantation. It also raises important ethical and regulatory considerations, both those common to research involving human embryos, as well as those unique to stem cell-based embryo and endometrial models. This review examines the underpinning scientific discoveries that have led to the development of this rapidly expanding area of research, and how three-dimensional embryo models could be employed in advancing assisted reproductive technologies and understanding implantation failure. Importantly, we also discuss the ethical and legal implications and explore various governance models that have been proposed to foster responsibility and innovation in this area of research. Given the heightened interest in the scientific community on this topic, we finish on the question of how and when to involve the public in the development of this technology and its regulation. Full article

Background/Objectives: Prostate cancer is the second most common type of cancer diagnosed in men. Various treatments for this cancer, such as radiation therapy, surgery, and systemic therapy, can cause side effects in patients; therefore, there is a need to develop new treatment alternatives. One promising approach is virotherapy, which involves using oncolytic viruses (OVs), such as the recombinant Newcastle disease virus (rNDV). Methods: We used the lentogenic rNDV rLS1 strain (the control virus) as our backbone to develop two highly fusogenic rNDVs: rFLCF5nt (the parental virus) and rFLCF5nt-IFN-γ (rFLCF5nt expressing human interferon-gamma (IFN-γ)). We evaluated their oncolytic properties in a prostate cancer cell line (DU145). Results: The results showed the expression and stability of the IFN-γ protein, as confirmed using Western blotting after ten passages in specific pathogen-free chicken embryo eggs using the IFN-γ-expressing virus. Additionally, we detected a significantly high oncolytic activity in DU145 cells infected with the parental virus or the IFN-γ-expressing virus using MTS (a cell viability assay) and Annexin V-PE assays compared with the control virus (p < 0.0001 for both). Conclusions: In conclusion, our data show that IFN-γ-expressing virus can decrease cell viability and induce apoptosis in human prostate cancer in vitro. Full article

During aging, the brain vasculature undergoes significant deterioration characterized by increased arterial tortuosity, compromised blood–brain barrier integrity, and reduced cerebral blood flow, all of which contribute to various neurological disorders. Thus, understanding the mechanisms underlying aging-related cerebrovascular defects is critical for developing strategies to alleviate aging-associated neurological diseases. In this study, we investigated the role of aging-related genes in brain vascular development using zebrafish as an in vivo model. By thoroughly analyzing scRNA-seq datasets of mid- and old-aged brain vascular endothelial cells (human/mouse), we found ribosomal protein S20 (rps20) significantly down-regulated during aging. qPCR analysis and whole-mount in situ hybridization validated a high expression of rps20 during early zebrafish development, which progressively decreased in adult and aged zebrafish brains. Functional studies using the CRISPR/Cas9-mediated knockout of rps20 revealed an impaired growth of central arteries in the hindbrain and a marked increased intracranial hemorrhage incidence. Mechanistically, qPCR analysis demonstrated a significant downregulation of vegfa, cxcl12b, and cxcr4a, key signaling molecules required for hindbrain vascular development, in rps20-deficient embryos. In conclusion, our findings demonstrate that rps20 is essential for proper brain vascular development and the maintenance of vascular homeostasis in zebrafish, revealing a novel mechanism by which aging-related genes regulate brain vascular development. This study provides new insights that may aid in understanding and treating aging-associated vascular malformations and neurological pathologies. Full article

Per- and polyfluoroalkyl substances (PFASs) comprise a diverse array of synthetic chemicals that resist environmental degradation. They are increasingly recognised as endocrine-disrupting compounds (EDCs). These chemicals, found in non-stick cookware, food packaging, and industrial waste, accumulate in human tissues and fluids, raising substantial concerns regarding their impact on female reproductive health. Epidemiological studies have demonstrated associations between PFAS exposure and reduced fertility; nevertheless, the underlying molecular pathways remain inadequately understood. This narrative review investigates the multifaceted effects of PFASs on ovarian physiology, including its disruption of the hypothalamic–pituitary–ovarian (HPO) axis, alteration of anti-Müllerian hormone (AMH) levels, folliculogenesis, and gonadotropin receptor signalling. Significant attention is directed towards the emerging association between PFASs and polycystic ovarian syndrome (PCOS), wherein PFAS-induced hormonal disruption may exacerbate metabolic issues and elevated androgen levels. Furthermore, we analyse the current data regarding PFAS exposure in women undergoing treatment based on assisted reproductive technologies (ARTs), specifically in vitro fertilisation (IVF), highlighting possible associations with diminished oocyte quality, suboptimal embryo development, and implantation failure. We examine potential epigenetic and transgenerational alterations that may influence women’s reproductive capabilities over time. This study underscores the urgent need for further research and regulatory actions to tackle PFAS-related reproductive toxicity, particularly in vulnerable populations, such as women of reproductive age and those receiving fertility treatments. Full article

Nitric oxide (NO) predominantly regulates endometrial receptivity, angiogenesis, immunological tolerance, and trophoblast invasion throughout the implantation period. Both insufficient and excessive nitric oxide production have been linked to suboptimal embryo implantation and infertility. The primary enzymatic source of uterine nitric oxide, along with hormonal, metabolic, and immunological variables and genetic variations in the endothelial nitric oxide synthase gene (NOS3), affects endothelial nitric oxide synthase (eNOS). Despite its considerable importance, there is limited knowledge regarding the practical implementation of nitric oxide-related diagnoses and therapies in reproductive medicine. A comprehensive assessment was performed in accordance with the PRISMA principles. Electronic searches were carried out in PubMed, Scopus, and Embase, and we analyzed the literature published from 2000 to 2024 regarding the association between NO, its metabolites (NO₂⁻ and NO₃⁻), eNOS expression, NOS3 gene variants, and reproductive outcomes. Relevant studies encompassed clinical trials, observational studies, and experimental research using either human or animal subjects. We collected data about therapeutic interventions, hormonal and immunological associations, nitric oxide measurement techniques, and in vitro fertilization success rates. A total of thirty-four studies were included. Dysregulated nitric oxide signaling, characterized by modified eNOS expression, oxidative stress, or NOS3 polymorphisms (e.g., Glu298Asp and intron 4 VNTR), was linked to diminished endometrial receptivity and an elevated risk of implantation failure and miscarriage. The dynamics of local uterine NO are essential as elevated and diminished systemic levels of NO₂⁻/NO₃⁻ corresponded with enhanced and decreased implantation rates, respectively. Among many therapeutic approaches, targeted hormone treatments, antioxidant therapy, and dietary nitrate supplements have demonstrated potential in restoring nitric oxide balance and enhancing reproductive outcomes. In animal models, the modification of nitric oxide significantly impacted decidualization, angiogenesis, and embryo viability. Nitric oxide is a multifaceted molecular mediator with considerable ramifications for successful implantation. Its therapeutic and diagnostic efficacy increases with its sensitivity to environmental, hormonal, and genetic alterations. Integrating targeted nitric oxide modulation, oxidative stress assessment, and NOS3 genotyping with personalized reproductive therapy will enhance endometrial receptivity and improve IVF outcomes. Future translational research should incorporate nitric oxide signaling into personalized treatment protocols for patients with unexplained infertility or recurrent implantation failure. Full article

Characteristic manifestations of skin aging, due to either intrinsic or extrinsic factors, such as ultraviolet (UV) radiation and oxidative stress, include cell senescence, alterations in collagen and elastin networks, and melanogenesis disorders. Natural products are considered a rich source of anti-aging molecules. Accordingly, the screening of a plant extract library from the Greek flora for a panel of biological activities related to skin aging is presented herein. In particular, 52 plant materials extracted using Accelerated Solvent Extraction (ASE) and Supercritical Fluid Extraction (SFE) were assessed for their effects on (1) human skin cell viability, (2) antioxidant activity—using both cell-free and cell-based methods—(3) photoprotective capacity, and (4) interference with collagenase, elastase, and tyrosinase, as well as with proteasomal and lysosomal activities of human skin cells. In vivo phenotypic screens on Danio rerio (zebrafish) embryos were also used for assessing melanogenesis. Many active extracts were identified, some of them for the first time, and others in agreement with previous reports. In general, ASE extracts exhibited higher activities than SFE ones. Seven extracts showed multiple activities, being highly effective in at least four different assays. These data support the potential use of these extracts against skin aging in medicinal and cosmetic applications. Full article

The aims of the present study were to analyze the taxonomic profile and to evaluate the functional effects of sheep FF cultivable microbiota on prepubertal lamb oocytes PLOs developmental potential. Ovarian FFs were recovered from slaughtered adult sheep via the aspiration of developing follicles and used for microbiota propagation. Bacterial pellets underwent 16S rRNA gene sequencing and targeted culturomics, whereas cell-free supernatants were used as supplements for the in vitro maturation (IVM) of slaughtered PLOs. For the first time, bacteria presence in adult sheep FF was detected, with the first report of Streptococcus infantarius subsp. infantarius (as a species) and Burkholderia cepacia (as a genus and species) in either animal or human FF. The short- and long-term effects of bacterial metabolites on PLO maturation and embryonic development were demonstrated. As short-term effects, the addition of FF microbiota metabolites did not affect the oocyte nuclear maturation and mitochondria distribution pattern, except in one of the examined supernatants, which reduced all quantitative bioenergetic/oxidative parameters. As long-term effects, one of them reduced the total cleavage rate after in vitro embryo culture (IVC). In conclusion, microbiota/bacteria are present in adult sheep FF and may influence reproductive outcomes in vitro. Future studies may reveal the beneficial in vitro effects using the microbiome from preovulatory follicles. Full article