Biology subjects

Sanchez, M.

Publications and source records attributed to Sanchez, M..

At least 19 recordsLinked to original sources

bioRxiv2026

Dual ecological-cultural pathways of sociocultural environment and resting state functional connectivity among Hispanic adolescents in the ABCD Study

Hispanic Americans face persistent health disparities rooted in complex sociocultural and bioecodevelopmental dynamics. Identifying early neurodevelopmental trajectories that confer risk or resilience during adolescence is critical for developing targeted health equity interventions. Grounded in the NIMHD Research Framework and bioecodevelopmental theory, data from 12- to 14-year-old Hispanic adolescents in the Adolescent Brain Cognitive Development (ABCD) Study were analyzed (n=236). Partial least squares correlation (PLSC) was used to evaluate multivariate associations between sociocultural measures, spanning individual, family, and community levels, and resting-state functional connectivity (rsFC) networks. Post hoc linear mixed-effects models examined how derived sociocultural-rsFC patterns predicted measures of physical and mental health, linking bioecodevelopmental patterns to adolescent well-being. PLSC revealed dual community- and family-level neural pathways of biological embedding, diverging from traditional nested bioecodevelopmental assumptions. The community pathway linked child opportunity and neighborhood disadvantage to connectivity across Cingulo-Opercular, Default, Dorsal Attention, Visual Networks. This community-rsFC profile was associated with lower respiratory functioning, reflecting an allostatic load marker of environmental stress. The family pathway linked caregiver ethnic identity and heritage acculturation to Default, Ventral Attention, Sensorimotor-Mouth, and Visual Networks connectivity, suggesting that the family system shapes neural systems underlying social attunement and identity formation. Structural community factors and familial culture impose distinct neurobiological demands on the adolescent connectome among Hispanic youth. Findings highlight respiratory health as a biological marker of environmental adversity and underscore the necessity of structural and culturally sustaining interventions to promote health equity among Hispanic youth.

neuroscience↗

bioRxiv2026

A transcriptome atlas of pea seed development guides the identification of PsLEC1-like as a key regulator of seed size

Grain legumes such as pea (Pisum sativum L.) accumulate large amounts of seed storage proteins without nitrogen fertilization due to their symbiosis with nitrogen-fixing bacteria, making them a key source of plant-based proteins. Seed growth and the accumulation of seed storage proteins are tightly regulated by complex gene networks; however, the mechanisms governing these processes in pea remain poorly understood. In this study, we generated a comprehensive seed expression atlas covering six developmental stages in pea (cv Cameor), including the key transition stage from embryogenesis to early seed filling, providing a detailed temporal resolution of transcriptional dynamics throughout seed development in this species. Co-expression network analysis highlighted several candidate transcription factors potentially involved in the transition towards seed filling. Among them, we characterized the seed-specific NF-YB transcription factor PsLEC1-like (PsL1L), the major LEC1-type factor expressed during early pea seed development. Functional analyses using TILLING mutants demonstrated that loss of PsL1L function reduces seed size and seed nitrogen content and impairs early embryo growth from the end of embryogenesis. Finally, we show that the expression of the B3-domain transcription factor PsFUS3, but not that of PsLEC2 or PsABI3, is reduced in the loss-of-function l1l mutant, suggesting that PsL1L acts upstream of PsFUS3 to control seed size.

plant biology↗

bioRxiv2025

GM1-oligosaccharide rescues rotenone-impaired neuronal polarization through RhoA/ROCK modulation and mitochondrial protection

Neuronal polarization is a fundamental process in the formation of functional neural circuits, relying on the precise coordination between cytoskeletal regulatory signals and mechanisms that sustain cellular integrity. Disruption of these processes compromises neuronal differentiation and survival, and various neurotoxic compounds, including certain pesticides, have been associated with such dysfunctions. In this context, identifying molecules that counteract these detrimental effects is of significant therapeutic interest. Neuronal polarization is essential for the establishment of functional neural circuits and relies on coordinated regulation of actin cytoskeleton dynamics, RhoA/ROCK signaling, and mitochondrial function. Here, we investigated the neuroprotective and neurorestorative potential of the ganglioside GM1 and its oligosaccharide derivative, osGM1, in primary hippocampal pyramidal neurons exposed to the mitochondrial neurotoxin rotenone. Rotenone induced a marked arrest of neuronal development, impaired axonal elongation, and disrupted mitochondrial organization and membrane potential. Both GM1 and osGM1 promoted recovery of neuronal polarity and axonal growth, exerting protective and restorative effects even under continuous toxin exposure, with osGM1 showing superior efficacy. Notably, osGM1 also reversed axonal growth deficits caused by pathological actin stabilization. Mechanistically, osGM1 normalized rotenone-induced hyperactivation of the RhoA/ROCK pathway without altering basal signaling and partially restored mitochondrial network integrity and function. Collectively, these findings identify osGM1 as a multi-target modulator of cytoskeletal and mitochondrial dysfunction and support its translational potential as a therapeutic strategy to counteract neurotoxin-induced neuronal damage.

neuroscience↗

bioRxiv2025

Ethnic Identity Profiles Among Adolescents in the ABCD Study: Associations with Resting State Functional Connectivity and Perceived Discrimination

Ethnic identity refers to how individuals perceive and experience themselves in the context of social groups, racial background, or culture (Phinney & Ong., 2007). Ethnic identity is positively associated with psychological well-being (Rivas-Drake et al., 2014) and negatively associated with depression and anxiety (Forstmeier et al., 2021). Those with strong ethnic identity may display resiliency to the negative effects of discrimination on psychological well-being (Urzua et al., 2021). Phinneys model describes four profiles for how people put effort into, participate in, and reflect upon their ethnic identity (Phinney, 1989). Despite prior work addressing ethnic identity and psychosocial outcomes (for review, see Meca et al., 2023), few studies have considered its neurobiological underpinnings. In the current study, we identified profiles of ethnic identity among participants in The Adolescent Brain Cognitive Development Study (ABCD Study) using latent profile analysis. Next, we examined resting state functional connectivity differences across observed profiles and assessed the moderating effects of perceived discrimination. Results indicated heightened cingulo-parietal (CPAR) network connectivity among adolescents with highly diffuse ethnic identities; among moderately achieved ethnic identities, perceived discrimination moderated the association between ethnic identity and CPAR connectivity. We discuss how these findings may be related to attentional shift, error monitoring, autobiographical memory, and social judgements.

neuroscience↗

bioRxiv2025

Spatial Biology and Organoid Technologies Reveal a Potential Therapy-Resistant Cancer Stem Cell Population in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) remains one of the deadliest malignancies with a 5-year survival rate of less than 10%. Chemotherapy is the current standard-of-care (SOC) for advanced PDAC; however, treatment resistance driven by a complex and immunosuppressive tumor microenvironment (TME) limits its effectiveness. To address mechanisms of resistance, we studied cabozantinib (cabo), a multi-kinase inhibitor approved for several solid tumors. Cabo has shown promise in preclinical PDAC models and clinical trials, particularly when combined with immunotherapy, but its mechanisms of action within the human PDAC TME and its potential to overcome therapy resistance remain unclear. Using CosMx Spatial Molecular Imaging (CosMx SMI) and Orion Multiplex Immunofluorescence (MxIF), we analyzed PDAC tissues collected after first line systemic chemotherapy and the Whipple surgical procedure, as well as from liver or lung metastatic sites from patients with PDAC. To functionally model the TME, we established matched patient-derived organoid (PDO) co-cultures harboring cancer associated fibroblasts (CAFs), and autologous immune cells (IMM) (PDO/CAF/IMM). These models were used to evaluate the effects of cabo and pembrolizumab, an anti-PD1 immune checkpoint inhibitor, with benchmarking of findings to the patients TME. Spatial analysis of post-chemotherapy and metastatic PDAC tissues revealed heterogeneous cellular neighborhoods within the TME, including enrichment of Schwann cells, CAFs, T regulatory cells, and cancer stem cells (CSCs). Distinct niches were observed in metastatic liver tissues, characterized by mesenchymal stem cells, fibroblasts, including myCAFs and iCAFs, and CSCs expressing CD44 and TROP2. In PDO/CAF/IMM co-cultures, treatment with cabo in combination with pembrolizumab enhanced cancer cell death by depleting myeloid-derived suppressor cells (MDSCs) and promoted cytotoxic T lymphocyte proliferation. Across both patient tissues and treated co-cultures, a persistent SOC-resistant cancer stem cell population emerged that expressed CD44 variant 9 (CD44v9). Taken together, these integrative spatial and organoid-based studies demonstrate that cabo can remodel the PDAC TME and potentiate PD-1 immunotherapy in preclinical models, while resistance associates with a CD44v9+ CSC population, revealing a potential therapeutic target.

cancer biology↗

bioRxiv2025

Large Scale Cell Painting Guided Compound Selection Reveals Activity Cliffs and Functional Relationships

Traditional structure-based pre-screen compound selection relies on the assumption that chemical similarity implies similar biological activity. This paradigm narrows the exploration of chemical space and often fails to account for functional convergence, where structurally diverse compounds act through distinct targets to produce similar phenotypic effects. As a result, compounds with therapeutic potential may be overlooked. To overcome this constraint, we introduce a training-free, transfer learning-based method for large scale compound preselection that leverages deep phenotypic profiling of human cells. Notably, this enables robust pairwise comparison of phenotypic signatures across any source of the entire JUMP-CP, the largest publicly available cell painting dataset (112,480 compounds), preserving biological signals while mitigating batch effects. Validated across 65 high-throughput assays--including in vitro and in cellulo systems--our method provides efficient pre-screen enrichment of biologically active compounds, bypassing the blind spots of structure-centric approaches. Interestingly, because it is large scale, it also allows for a comprehensive analysis of structure-phenotypic activity relationships, revealing potentially thousands of compound activity cliffs, where minimal chemical changes in structure may result in profound phenotypic shifts. We show that these cliffs capture subtle, atom-level determinants of bioactivity that cannot be accessed by structure-based models. Furthermore, we demonstrate that structurally diverse compounds targeting different genes in the same biological pathway can induce either convergent or opposite phenotypes--a phenomenon validated across 30 pathways, hundreds of genes, and thousands of compounds. Finally, to support the broader community, we propose Phenoseeker, a web-based tool enabling instant retrieval of JUMP-CP compounds with similar phenotypic profiles. Together, these findings position phenotypic profiling not merely as a complementary tool, but as a transformative and scalable framework for navigating chemical space through a biological lens. By capturing rich morphological signatures that reflect functional outcomes--regardless of structural similarity--this approach enables the discovery of bioactive compounds, novel mechanisms of action, and unexpected target-pathway relationships. Applied at the scale of the JUMP-CP dataset, phenotypic profiling emerges as a powerful strategy for prioritizing compounds, illuminating activity cliffs, and accelerating the identification of therapeutically relevant candidates across diverse biological contexts.

bioinformatics↗

bioRxiv2025

PP4Psy2 regulates Rrm3 and Pif1 helicases to facilitate DSB resection across tandem retrotransposons

Double-strand break repair is a tightly regulated process that relies on the coordinated activity of kinase and phosphatase complexes. Here we show that the PP4 phosphatase regulatory subunits, Psy2 and Psy4, act as positive and negative regulators of the holoenzyme during DSB repair. Cdk-dependent phosphorylation of Psy2 is crucial for DSB repair but is not required for DNA damage checkpoint inactivation. Lack of Psy2 leads to an asymmetric resection defect on one side of the DSB, a defect that is alleviated by expressing a phosphodeficient H2A variant or by depleting the checkpoint adaptor Rad9. This resection asymmetry is associated to the presence of tandem retrotransposons proximal to the DSB site, underlining the role of PP4Psy2 in stimulating resection across repetitive heterochromatic regions. PP4Psy2 support resection progression through paired transposable elements by reducing the phosphorylation state of Pif1 and Rrm3 helicases during the DSB response. These findings provide a comprehensive framework for the role of PP4Psy2 in resection-mediated DSB repair, highlighting its function in coordinating helicases activity to preserve genomic stability in response to DNA damage.

molecular biology↗

bioRxiv2025

A spatially resolved single cell proteomic atlas of Small Bowel Adenocarcinoma

Small bowel adenocarcinoma (SBA) is a rare malignancy marked with a poor prognosis. The cellular and proteomic heterogeneity within the tumor immune microenvironment (TIME) of SBA is a likely driver of prognosis, disease progression and response to therapy. We have addressed a major gap in knowledge of the TIME in SBA using highly multiplexed, protein imaging of the SBA tumor-immune ecosystem generating a comprehensive, single-cell level, spatial, proteomic atlas of TIME in > 600,000 cells from 136 tumor and matched normal samples from clinically and genomically annotated SBA patients (N=37). The SBA TIME Atlas informs on spatial distribution and interactions of tumor-intrinsic processes, diverse immune cell types, immune checkpoints, and vascularization. Enrichment of proliferating epithelial tissue, stem cells, and likely pro-tumor immune signatures in the tumor niche is contrasted by the representation of naive and early-effector T-cells in the epithelial compartments of adjacent normal tissues. Epithelial-stem-immune cell spatial architectures within tumor and matched-normal niches were strongly associated with patient survival, suggesting malignancy is driven by spatial architecture beyond the tumor microenvironment. The blueprints of therapeutically actionable immune checkpoints at the interface between epithelial and microenvironmental T-cells as well as macrophages have established a guideline for precision immunotherapies tailored to the TIME composition in SBA. We expect that this SBA atlas will contribute to a deeper understanding of the immune contexture in this rare disease as well as other gastrointestinal cancers and help guide future precision immune-oncology strategies.

cancer biology↗

bioRxiv2024

A novel epigenetic clock for rhesus macaques unveils an association between early life adversity and epigenetic age acceleration

Because DNA methylation changes reliably with age, machine learning models called epigenetic clocks can estimate an individuals age based on their DNA methylation profile. This epigenetic measure of age can deviate from ones true age, and the difference between the epigenetic age and true age, known as epigenetic age acceleration (EAA), has been found to directly correlate with morbidity and mortality in adults. Emerging evidence suggests that EAA is also associated with aberrant health outcomes in children, making epigenetic clocks useful tools for studying aging and development. We developed two highly accurate epigenetic clocks for the rhesus macaque, utilizing 1,008 blood samples from 690 macaques between 2 days and 23.4 years of age with diverse genetic backgrounds and exposure to environmental conditions. The first clock, which is trained on all samples, achieves a Pearson correlation between true age and predicted age of 0.983 and median absolute error of 0.210 years. To study phenotypes during development, the second clock is optimized for macaques younger than 6 years and achieves a Pearson correlation of 0.974 and a median absolute error of 0.148 years. Using the latter clock, we investigated whether epigenetic aging is affected by early life adversity in the form of infant maltreatment. Our data suggests that maltreatment and increased hair cortisol levels are associated with epigenetic age acceleration right after the period of maltreatment.

neuroscience↗

bioRxiv2024

Validation of DoriVac (DNA origami vaccine) efficacy in a metastatic melanoma model

Metastatic cancer, particularly metastatic melanoma, poses a significant therapeutic challenge due to its resistance to standard treatments and low five-year survival rate of 20-27%. Current therapies show limited success, highlighting the urgent need for novel interventions. Recent advances in cancer vaccine research show great promise in reducing disease recurrence, but these approaches still face challenges pertaining to antigen selection, ease of production, and programmability. To address some of these challenges, we have adapted the DoriVac platform to serve as a cancer vaccine against metastatic melanoma. DoriVac is a DNA origami-based vaccine platform that allows for the codelivery of antigens of choice and the CpG immune adjuvant at an optimal nanospacing to promote Th1 immune polarization. In our study, we observed a significant reduction in lung tumor nodules for mice treated with DoriVac in both the B16OVA and B16F10 melanoma mouse models. DoriVac also appears to be a safe and effective treatment, with no anti-drug antibodies, as indicated by lower anti-dsDNA levels. Importantly, we observed an amplified effect when DoriVac was combined with PD-L1 immune checkpoint blockade, leading to an even greater reduction in metastatic lung tumor nodules. Our results also indicate an increased activation of antigen presenting cells, NK cells, CD4+ T cells and CD8+ T cells. These findings suggest that DoriVac, particularly in combination with the PD-L1 immune checkpoint blockade, can serve as a promising immunotherapy against metastatic cancer.

synthetic biology↗

bioRxiv2024

STANDARDISED FLOW CYTOMETRIC PROCEDURE FOR DEEP CHARACTERIZATION OF NANOPARTICLES

In recent years, there has been a notable increasing interest surrounding the identification and quantification of nanosized particles, including extracellular vesicles (EVs) and viruses. The challenge posed by the nano-sized dimension of these particles makes precise examination a significant undertaking. Among the different techniques for the accurate study of EVs, Flow cytometry (FCM) stands out as the ideal method. It is characterized by high sensitivity, low time consumption, non-destructive sampling, and high throughput. In this article, we propose the optimization of FCM procedures to identify, quantify, and purify EVs and virus like particles (VLPs). The protocol aims to reduce artifacts and errors in nano-sized particles counting, overall caused by the swarming effect. Different threshold strategies were compared to ensure result specificity. Additionally, the critical parameters to consider when using conventional FCM outside of the common experimental context of use have also been identified. Finally, fluorescent-EVs sorting protocol was also developed with highly reliable results using a conventional cell sorter.

cell biology↗

bioRxiv2024

SYSTEMIC FRATAXIN DEFICIENCY CAUSES TISSUE-DEPENDENT IRON HOMEOSTASIS ALTERATIONS: IMPLICATIONS FOR FRIEDREICH ATAXIA

Friedreich Ataxia (FA) is a cardio-neurodegenerative disease caused by mutations in the frataxin gene, which result in low frataxin expression. It is well-established that frataxin deficiency affects iron homeostasis, but the tissue-specificity of these alterations is poorly understood. In this study, we have analyzed iron homeostasis alterations in the FXNI151F mouse model, which presents systemic frataxin deficiency and neurological defects resembling FA patients. Iron overload is observed in the brain from 21-week old FXNI151F mice, both males and females, and it does not further accumulate in older animals. It is also observed in livers from 39-week old mutant females, but not in males. Iron signaling is altered in all tissues: in brain and liver Iron Regulatory Protein 1 (IRP1) content is decreased, while in heart increased IRP2 and decreased specific aconitase 2 activity are observed. Remarkably, these cardiac alterations are partially restored in 39- week-old animals, suggesting that the heart is activating an iron-deficiency response to compensate for deficient iron-sulfur biogenesis. Our findings demonstrate that frataxin deficiency affects iron homeostasis in a time dependent and tissue-specific manner, and that the pathological mechanisms in FA comprise both iron accumulation and limited iron availability. Understanding this specificity is crucial for the design of iron-related therapeutic interventions aiming to improve FA symptomatology.

biochemistry↗

bioRxiv2024

DNA origami vaccine (DoriVac) nanoparticles improve both humoral and cellular immune responses to infectious diseases

Current SARS-CoV-2 vaccines have demonstrated robust induction of neutralizing antibodies and CD4+ T cell activation, however CD8+ responses are variable, and the duration of immunity and protection against variants are limited. Here we repurposed our DNA origami vaccine nanotechnology, DoriVac, for targeting infectious viruses, namely SARS-CoV-2, HIV, and Ebola. The DNA origami nanoparticle, conjugated with infectious-disease-specific heptad repeat 2 (HR2) peptides, which act as highly conserved antigens, and CpG adjuvant at precise nanoscale spacing, induced neutralizing antibodies, Th1 CD4+ T cells, and CD8+ T cells in naive mice, with significant improvement over a bolus control. Pre-clinical studies using lymph-node-on-a-chip systems validated that DoriVac, when conjugated with antigenic peptides or proteins, induced promising cellular and humoral immune responses in human cells. Moreover, DoriVac bearing full-length SARS-CoV-2 spike protein achieved immune responses comparable to current mRNA vaccine platforms while potentially reducing storage constraints. These results suggest that DoriVac holds potential as a versatile, modular vaccine platform, capable of inducing both humoral and cellular immunities, underscoring its potential utility in addressing future pandemics.

immunology↗

bioRxiv2023

Unveiling Cryptosporidium parvum Sporozoite-Derived Extracellular Vesicles: Profiling, Origin, and Protein Composition

Cryptosporidium parvum is a common cause of a zoonotic disease and a main cause of diarrhea in newborns around the world. Effective drugs or vaccines are still lacking. Oocyst is the infective form of the parasite; after the ingestion the oocyst excysts and releases four sporozoites into the intestine that rapidly attack the enterocytes. The membrane protein CpRom1 is a large rhomboid protease that is expressed by sporozoites and recognized as antigen by the host immune system. In this study, we observed the release of CpRom1 with extracellular vesicles (EVs) not previously described. To investigate this phenomenon, we isolated and resolved EVs from the excystation medium by differential ultracentrifugation. By fluorescence flow cytometry and transmission electron microscopy (TEM), we identified two types of sporozoite-derived vesicles: large extracellular vesicles (LEVs) and small extracellular vesicles (SEVs), having different a mean size of 150 nm and 60 nm, respectively. Immunodetection experiments proved the occurrence of CpRom1 and the Golgi protein CpGRASP in LEVs, while immune-electron microscopy experiments demonstrated localization of CpRom1 on LEVs surface. TEM and scanning electron microscopy (SEM) showed the generation of LEVs by budding of the outer membrane of sporozoites; conversely, the origin of SEVs remained uncertain. Differences between LEVs and SEVs were observed for protein composition as proved by the corresponding electrophoretic profiles. Indeed, a dedicated proteomic analysis identified 5 proteins unique to LEVs composition and 16 proteins unique to SEVs. Overall, 60 proteins were identified in the proteome of both types of vesicles and most of these proteins (48 in number) were already identified in the molecular cargo of extracellular vesicles from other organisms. Noteworthy, we identified 12 proteins unique to Cryptosporidium spp. that had never been associated with EVs. This last group included the immunodominant parasite antigen glycoprotein GP60, which is one of the most abundant proteins in both LEVs and SEVs.

microbiology↗

bioRxiv2023

A large-scale volumetric correlated light and electron microscopy study localizes Alzheimer's disease-related molecules in the hippocampus

Connectomics using volume-electron-microscopy enables mapping and analysis of neuronal networks, revealing insights into neural circuit function and dysfunction. In Alzheimers disease (AD), where amyloid-{beta} (A{beta}) and hyperphosphorylated-Tau (pTau) are implicated, connectomics offers an approach to unravel how these molecules contribute to circuit alterations by enabling the study of these molecules within the context of the complete local neuronal and glial milieu. We present a volumetric-correlated-light-and-electron microscopy (vCLEM) protocol using fluorescent nanobodies to localize A{beta} and pTau within a large-scale connectomics dataset from the hippocampus of the 3xTg AD mouse model. A key outcome of this work is a publicly accessible vCLEM dataset, featuring fluorescent labeling of A{beta} and pTau in the ultrastructural context with segmented neurons, glia, and synapses. This dataset provides a unique resource for exploring AD pathology in the context of connectomics and fosters collaborative opportunities in neurodegenerative disease research. As a proof-of-principle, we uncovered new localizations of A{beta} and pTau, including pTau-positive spine-like protrusions at the axon initial segment and changes in the number and size of synapses near A{beta} plaques. Our vCLEM approach facilitates the discovery of both molecular and structural alterations within large-scale EM data, advancing connectomics research in Alzheimers and other neurodegenerative diseases.

neuroscience↗

bioRxiv2023

The cervical microbiota of Hispanics living in Puerto Rico is highly volatile and dominated by L. iners regardless of HPV status

IntroductionThe cervicovaginal microbiota is influenced by host physiology, immunology, lifestyle, and ethnicity. We hypothesized that there would be differences in the cervicovaginal microbiota among pregnant, non-pregnant and menopausal women living in Puerto Rico with and without Human Papillomavirus (HPV) infection and cervical cancer. We specifically wanted to determine if the microbiota associated with variation in cervical cytology. A total of 294 women comprised of reproductive-age non-pregnant (N=196), pregnant (N=37), and menopausal (N=61) women were enrolled. The cervicovaginal bacteria was characterized by 16S rRNA amplicon sequencing, the HPV were genotyped with SPF10-LiPA, and cervical cytology was quantified. High-risk HPV (HR-HPV, 67.3%) was prevalent, including genotypes not covered by the 9vt HPV vaccine. Cervical lesions (34%) were also common. The cervical microbiota was dominated by Lactobacillus iners. Pregnant women in the 2nd and 3rd trimesters had decreased diversity and a decreased abundance of microbes associated with bacterial vaginosis. Women in menopause had greater alpha diversity, a greater proportion of facultative and strictly anaerobic bacteria, and higher cervicovaginal pH than pre-menopausal women. Cervical lesions were associated with greater alpha diversity. However, no significant associations between the microbiota and HPV infection (HR or LR-HPV types) were found. The cervicovaginal microbiota women living in Puerto Rican were either dominated by L. iners or diverse microbial communities regardless of a womans physiological stage. We postulate that the microbiota and the high prevalence of HR-HPV, increase the risk of cervical lesions of women living in Puerto Rico.

microbiology↗

bioRxiv2023

Improved rescue of immature oocytes obtained from conventional gonadotropin stimulation cycles via human induced pluripotent stem cell-derived ovarian support cell co-culture

Structured AbstractO_ST_ABSPurposeC_ST_ABSTo determine if rescue in vitro maturation (IVM) of human oocytes can be improved by co-culture with ovarian support cells (OSCs) derived from human induced pluripotent stem cells (hiPSCs). MethodsFertility patients undergoing conventional ovarian stimulation for oocyte cryopreservation or IVF donated denuded immature germinal vesicle (GV) and metaphase I (MI) oocytes for research, which were allocated between either the control or intervention cultures. Fertility patients aged 25 to 45 years old donated immature oocytes under informed consent, with no additional inclusion criteria. The 24-28 hour OSC-IVM culture condition was composed of 100,000 OSCs in suspension culture with human chorionic gonadotropin (hCG), recombinant follicle stimulating hormone (rFSH), androstenedione and doxycycline supplementation. The Media-IVM control lacked OSCs and contained the same supplementation. Primary endpoints consisted of MII formation rate and morphological quality assessment. Additionally, metaphase spindle assembly location and oocyte transcriptomic profiles were assessed compared to in vivo matured MII oocyte controls. ResultsWe observed significant improvement in maturation outcome rates ([~]1.7X) for oocytes that underwent IVM with OSCs. Specifically, the OSC-IVM group yielded a maturation rate of 62% {+/-} 5.57% SEM versus 37% {+/-} 8.96% SEM in the Media-IVM (p=0.0138, unpaired t-test). Oocyte morphological quality between OSC-IVM and the Media-IVM control did not significantly differ. OSC-IVM resulted in MII oocytes with no instances of spindle absence and no significant difference in position compared to in vivo matured IVF-MII controls. OSC-IVM treated MII oocytes display a transcriptomic signature significantly more similar to IVF-MII controls than the Media-IVM control MII oocytes did. ConclusionThe novel OSC-IVM platform is an effective tool for rescue maturation of human oocytes obtained from conventional stimulation cycles, yielding oocytes with improved nuclear and cytoplasmic maturation. OSC-IVM shows broad utility for application in modern fertility treatment to improve the total number of available mature oocytes for fertility treatment.

developmental biology↗

bioRxiv2023

Human induced pluripotent stem cell-derived ovarian support cell co-culture improves oocyte maturation in vitro after abbreviated gonadotropin stimulation

Assisted reproductive technologies (ART) have significantly impacted fertility treatment worldwide through innovations such as in vitro fertilization (IVF) and in vitro maturation (IVM). IVM holds promise as a technology for fertility treatment in women who cannot or do not wish to undergo conventional controlled ovarian stimulation (COS). However, IVM has historically shown highly variable performance in maturing oocytes and generating oocytes with strong developmental capacity. Furthermore, recently reported novel IVM approaches are limited to use in cycles lacking human chorionic gonadotropin (hCG) triggers, which is not standard practice in fertility treatment. We recently reported the development of ovarian support cells (OSCs) generated from human induced pluripotent stem cells (hiPSCs) that recapitulate dynamic ovarian function in vitro. Here we investigate the potential of the se OSCs in an IVM co-culture system to improve the maturation of human cumulus-enclosed immature oocytes retrieved from abbreviated gonadotropin stimulated cycles. We reveal that OSC-IVM significantly improves maturation rates compared to existing IVM systems. Most importantly, we demonstrate that OSC-assisted IVM oocytes are capable of significantly improving euploid blastocyst formation and yielding blastocysts with normal global and germline differential methylation region methylation profiles, a key marker of their clinical utility. Together, these findings demonstrate a novel approach to IVM with broad applicability to modern ART practice. Structured AbstractO_ST_ABSObjectiveC_ST_ABSTo determine if in vitro maturation (IVM) of human oocytes can be improved by co-culture with ovarian support cells (OSCs) derived from human induced pluripotent stem cells (hiPSCs). DesignThree independent experiments were performed in which oocyte donors were recruited to undergo abbreviated gonadotropin stimulation and retrieved cumulus oocyte complexes (COCs) were randomly allocated between the OSC-IVM and control IVM conditions. SubjectsAcross the three experiments, a total of 67 oocyte donors aged 19 to 37 years were recruited for retrieval using informed consent. Anti-mullerian hormone (AMH) value, antral follicle count (AFC), age, BMI, and ovarian pathology were used for inclusion and exclusion criteria. Intervention and ControlThe OSC-IVM culture condition was composed of 100,000 OSCs in suspension culture supplemented with human chorionic gonadotropin (hCG), recombinant follicle stimulating hormone (rFSH), androstenedione and doxycycline. IVM controls comprised commercially-available IVM media without OSCs and contained either the same supplementation as above (media-matched control), or FSH and hCG only (IVM media control). In one experiment, an additional control using fetal ovarian somatic cells (FOSCs) was used with the same cell number and media conditions as in the OSC-IVM. Main Outcome MeasuresPrimary endpoints consisted of metaphase II (MII) formation rate and oocyte morphological quality assessment. A limited cohort of oocytes were utilized for secondary endpoints, consisting of fertilization and blastocyst formation rates with preimplantation genetic testing for aneuploidy (PGT-A) and embryo epigenetic analysis. ResultsOSC-IVM resulted in a statistically significant improvement in MII formation rate compared to the media-matched control, a commercially available IVM media control, and the FOSC-IVM control. Oocyte morphological quality between OSC-IVM and controls did not significantly differ. OSC-IVM displayed a trend towards improved fertilization, cleavage, and blastocyst formation. OSC-IVM showed statistically significant improvement in euploid day 5 or 6 blastocyst formation compared to the commercially available IVM media control. OSC-IVM embryos displayed similar epigenetic global and germline loci profiles compared to conventional stimulation and IVM embryos. ConclusionThe novel OSC-IVM platform is an effective tool for maturation of human oocytes obtained from abbreviated gonadotropin stimulation cycles, supporting/inducing robust euploid blastocyst formation. OSC-IVM shows broad utility with different stimulation regimens, including hCG triggered and untriggered oocyte retrieval cycles, making it a highly useful tool for modern fertility treatment.

developmental biology↗