Project description:Cryopreservation is an important technique for preserving fertility potential through ovarian tissue banking. Slow freezing has traditionally been the standard protocol used for ovarian tissue cryopreservation. However, vitrification, as an emerging method, is considered to be an alternative to slow freezing, thus generating some debate in the field. This study utilizes high-resolution spatial transcriptomics to comprehensively profile and compare the molecular impacts of two cryopreservation methods - slow freezing and vitrification - on human ovarian tissues at an unprecedented resolution. Over 135,000 spots were profiled from Fresh and cryopreserved ovarian tissue slices, identifying 8 major cell types and 25 subtypes through marker expression. Detailed spatial localization patterns revealed heterogeneous stromal cell subpopulations and ovarian structures. Transcriptional profiling showed that both cryopreservation methods significantly repressed gene expression, indicative of tissue damage. However, slow freezing induced a broader pro-survival inflammatory and tissue remodeling response compared to vitrification. Gene set enrichment analysis identified elevated ribosomal processes, inflammatory signaling pathways like TNF-?/NF-?B and IL-6/STAT3, as well as extracellular matrix (ECM) organization and collagen synthesis as dominant response themes in slow frozen tissue, which were observed to a lesser degree in vitrified tissue. Key response drivers included MYC, TIMP1, and DCN, with stromal cells located in the cortical regions showing the strongest pathway enrichment. Ribosomal gene expression displayed spatial gradients and supported stromal responses after freezing. We finally demonstrated signaling pathway differences between the two cryopreservation methods, noting TGF-? as a highly possible pathway responsible for coordinating with certain endothelial subgroups to enhance ECM deposition. In summary, this study provides a comprehensive atlas of cell types and their spatial structures in human ovary. It reveals that slow freezing elicits a strong but balanced inflammatory and tissue regenerative state compared to the vitrification. It also offers insights on cryoinjury to ovarian stroma, which may guide optimization of ovarian tissue cryopreservation protocols for clinical applications.

Project description:The Portuguese oyster Crassostrea angulata, a bivalve of significant economic and ecological importance, has faced a decline in both production and natural populations due to pathologies, climate change, and anthropogenic factors. To safeguard its genetic diversity and improve reproductive management, cryopreservation emerges as a valuable strategy. However, the cryopreservation methodologies lead to some damage in structures and functions of the cells and tissues that can affect post-thaw quality. Transcriptomics may help to understand the molecular consequences related to cryopreservation steps and therefore to identify different freezability biomarkers. This study investigates the molecular damage induced by cryopreservation in C. angulata D-larvae, focusing on two critical steps: exposure to cryoprotectant solution and the freezing/thawing process. Expression analysis revealed 3 differentially expressed genes between larvae exposed to cryoprotectant solution and fresh larvae and 511 differentially expressed genes in cryopreserved larvae against fresh larvae. The most significantly enriched gene ontology terms were “carbohydrate metabolic process”, “integral component of membrane” and “chitin binding” for biological processes, cellular components and molecular functions, respectively. Kyoto Encyclopedia of Genes and Genomes enrichment analysis identified the “neuroactive ligand receptor interaction”, “endocytosis” and “spliceosome” as the most enriched pathways. RNA sequencing results were validate by quantitative RT-PCR, once both techniques presented the same gene expression tendency and a group of 11 genes were considered important molecular biomarkers to be used in further studies for the evaluation of cryodamage. The current work provided valuable insights into the molecular repercussions of cryopreservation on D-larvae of Crassostrea angulata, revealing that the freezing process had a more pronounced impact on larval quality compared to any potential cryoprotectant-induced toxicity. Additionally, was identify 11 genes serving as biomarkers of freezability for D-larvae quality assessment. This research contributes to the development of more effective cryopreservation protocols and detection methods for cryodamage in this species.

Project description:Studies on embryo cryopreservation efficiency had been focused mainly on technical and embryo factors. While structural damages can be easily evaluated, physiological damages only can be estimated by analyzing their in vitro and in vivo development to later stages. In order to determine how cryopreservation process affect embryo pre-implantory development, a transcriptional microarray study has been performed comparing gene expression of 6 days old rabbit embryos, previously vitrified or frozen and transferred into recipients rabbit females, to their in vivo counterparts. For each experimental group, control, vitrified and frozen late blastocysts, total RNA was extracted from 3 pools of approximately 10 embryos and labeled with Cy3 or Cy5 dyes. Then, six competitive hybridizations were carried out including two dye-swaps to compensate dye-bias. A specifically microarray designed to study rabbit gene expression profiling, the Rabbit 44K oligonucleotide array (Agilent Technologies), was used in this study. Identification of differentially expressed transcripts from 6 day old blastocysts was achieved using the Limma algorithm, and functional annotation was performed by Blast2GO software. Compared to 6 day old in vivo derived embryos, viable vitrified embryos only present 3 differentially expressed genes, in contrast to frozen viable embryos with 24 genes upregulated and 46 genes downregulated. These results reveal that effects of cryopreservation still remain in late blastocyst pre-implantatory gene expression, and potential damage and alterations produced by vitrification and slow-freezing procedures are differentially resolved after 3 days of in vivo development. Transcriptional microarray study that compares gene expression of viable 6 day old rabbit embryos, previosly vitrified or frozen and tranferred into recipient rabbit females, to their in vivo counterparts. Experiment 1: Control embryos vs. Vitrified embryos and Experiment 2: Control embryos vs. Frozen embryos. Biological replicates used: 3 replicates for control embryos, 3 replicates for vitrified embryos and 3 replicates for frozen embryos.

Project description:Thiele2013 - Ovary ovarian stroma cells The model of ovary ovarian stroma cells metabolism is derived from the community-driven global reconstruction of human metabolism (version 2.02, MODEL1109130000 ). This model is described in the article: A community-driven global reconstruction of human metabolism. Thiele I, et al . Nature Biotechnology Abstract: Multiple models of human metabolism have been reconstructed, but each represents only a subset of our knowledge. Here we describe Recon 2, a community-driven, consensus 'metabolic reconstruction', which is the most comprehensive representation of human metabolism that is applicable to computational modeling. Compared with its predecessors, the reconstruction has improved topological and functional features, including ~2x more reactions and ~1.7x more unique metabolites. Using Recon 2 we predicted changes in metabolite biomarkers for 49 inborn errors of metabolism with 77% accuracy when compared to experimental data. Mapping metabolomic data and drug information onto Recon 2 demonstrates its potential for integrating and analyzing diverse data types. Using protein expression data, we automatically generated a compendium of 65 cell type-specific models, providing a basis for manual curation or investigation of cell-specific metabolic properties. Recon 2 will facilitate many future biomedical studies and is freely available at http://humanmetabolism.org/. This model is hosted on BioModels Database and identified by: MODEL1310110029 . To cite BioModels Database, please use: BioModels Database: An enhanced, curated and annotated resource for published quantitative kinetic models . To the extent possible under law, all copyright and related or neighbouring rights to this encoded model have been dedicated to the public domain worldwide. Please refer to CC0 Public Domain Dedication for more information.

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High-Resolution Spatial Transcriptomics Reveals Stroma Damage in Human Ovarian Tissue Response to Cryopreservation

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