Project description:The present study explores the advantages of enriching the freezing medium with membrane lipids and antioxidants in improving the outcome of prepubertal testicular tissue cryopreservation. For the study, testicular tissue from Swiss albino mice of prepubertal age group (2 weeks) was cryopreserved by slow freezing method either in control freezing medium (CFM; containing DMSO and FBS in DMEM/F12) or test freezing medium (TFM; containing soy lecithin, phosphatidylserine, phosphatidylethanolamine, cholesterol, vitamin C, sodium selenite, DMSO and FBS in DMEM/F12 medium) and stored in liquid nitrogen (LN 2 ) for at least one week. The tissues were thawed and enzymatically digested to assess viability, DNA damage, and oxidative stress in the testicular cells. The results indicate that TFM significantly mitigated freeze-thaw-induced cell death, DNA damage, and lipid peroxidation compared to tissue cryopreserved in CFM. Further, a decrease in Cyt C, Caspase-3, and an increase in Gpx4 mRNA transcripts were observed in tissues frozen with TFM. Spermatogonial germ cells (SGCs) collected from tissues frozen with TFM exhibited higher cell survival and superior DNA integrity compared to those frozen in CFM. Proteomic analysis revealed that SGCs experienced a lower degree of freeze-thaw- induced damage when cryopreserved in TFM, as evident from an increase in the level of proteins involved in mitigating the heat stress response, and transcriptional and translational machinery. These results emphasize the beneficial role of membrane lipids and antioxidants in enhancing the cryosurvival of prepubertal testicular tissue offering a significant stride towards improving the clinical outcome of prepubertal testicular tissue cryopreservation.
Project description:ITo derive a scaffold from human testis for the purpose of tissue engineering and regenerative medicine, we developed a method to produce a cytocompatible decellularized testicular matrix (DTM) while maintaining the native tissue-specific characteristics and components. The potential benefits of tissue-specific scaffolds consisting of naturally-derived extracellular matrix (ECM) have been demonstrated using a wide variety of animal and human tissue sources. However, so far, testis scaffolds have never been considered for constructive remodelling purposes. We have therefore developed a protocol for the preparation of cell-free extracellular matrix and characterized the material extensively using a combination of proteomics, immunohistochemsitry, and cell population assays. To prepare cell-free matrix, human cadaveric testicular tissue was exposed for 24 h or 48 h to 1% Triton X-100 and/or 1% sodium dodecyl sulfate (SDS). The extent of decellularization was evaluated by histology. Confirmation of cell removal in DTM was done by a DNA quantification technique. The protein composition was analysed by LC-MS/MS. The retention of testicular tissue-specific characteristics was evaluated by immunohistochemistry, Alcian blue staining and scanning electron microscopy. Soluble toxicity and testicular cell attachment was assessed to check the cytocompatibility of DTM scaffolds. Histological analysis showed that DTM could be obtained by mechanical agitation in 1% SDS for 24 h. The resulting DTM was found to be clear of cells while retaining the typical three-dimensional structure. Proteomics analysis revelaed the presence of the major components of the native tissue scaffold, including collagen type I and IV, fibronectin, laminin and glycosaminoglycans. In addition, numerous additional ECM proteins in DTM were detected, indicating its complex nature. Importantly, we demonstrated that DTM scaffolds are not cytotoxic, as evidenced by MTT assay showing a normal fibroblast proliferation activity after indirect exposure, and support testicular cell attachment and infiltration.
Project description:Ovarian tissue cryopreservation is an important technique for preserving fertility potential, albeit the associated tissue damage may severely impact post-thaw tissue viability. We collected human ovarian tissues from multiple samples and performed Stereo-Seq high-resolution spatial transcriptomics to comprehensively profile and compare the molecular impacts of two cryopreservation methods - slow freezing and vitrification. We identified 8 major spatial clusters and revealed their functional heterogeneity by subclustering. We then detailed cryopreservation response at both the global and subcluster levels to illustrate overall and niche specific effects. Compared to fresh samples, we observed a decrease in major metabolic pathways in frozen samples with both techniques, whereas vitrified samples have severer decrease than slow-frozen samples. The affected metabolic pathways included those related to proteins, such as ribosomal processes and proteasomal degradation; lipids, specifically sterol and cholesterol metabolism; and overall energy production, which encompassed cellular respiration and mitochondrial processes. On the other hand, slow freezing elicited a strong but balanced inflammatory and tissue remodeling state compared to vitrification. We also reported upregulated cell-cell signaling related to angiogenesis, cellular adhesion and extracellular matrix remodeling in slow-frozen tissue. These pathways were responsible for enhancing tissue repair by coordinating with certain stromal and endothelial subclusters. In summary, our study offered insights on ovarian cell response to cryopreservation, which may guide optimization of ovarian tissue cryopreservation protocols for clinical applications.
Project description:ITo derive a scaffold from human testis for the purpose of tissue engineering and regenerative medicine, we developed a method to produce a cytocompatible decellularized testicular matrix (DTM) while maintaining the native tissue-specific characteristics and components. The potential benefits of tissue-specific scaffolds consisting of naturally-derived extracellular matrix (ECM) have been demonstrated using a wide variety of animal and human tissue sources. However, so far, testis scaffolds have never been considered for constructive remodelling purposes. We have therefore developed a protocol for the preparation of cell-free extracellular matrix and characterized the material extensively using a combination of proteomics, immunohistochemsitry, and cell population assays. To prepare cell-free matrix, human cadaveric testicular tissue was exposed for 24 h or 48 h to 1% Triton X-100 and/or 1% sodium dodecyl sulfate (SDS). The extent of decellularization was evaluated by histology. Confirmation of cell removal in DTM was done by a DNA quantification technique. The protein composition was analysed by LC-MS/MS. The retention of testicular tissue-specific characteristics was evaluated by immunohistochemistry, Alcian blue staining and scanning electron microscopy. Soluble toxicity and testicular cell attachment was assessed to check the cytocompatibility of DTM scaffolds. Histological analysis showed that DTM could be obtained by mechanical agitation in 1% SDS for 24 h. The resulting DTM was found to be clear of cells while retaining the typical three-dimensional structure. Proteomics analysis revelaed the presence of the major components of the native tissue scaffold, including collagen type I and IV, fibronectin, laminin and glycosaminoglycans. In addition, numerous additional ECM proteins in DTM were detected, indicating its complex nature. Importantly, we demonstrated that DTM scaffolds are not cytotoxic, as evidenced by MTT assay showing a normal fibroblast proliferation activity after indirect exposure, and support testicular cell attachment and infiltration.
Project description:Cryopreservation of mature oocytes is a critical means for female fertility preservation. Despite clinical advances using vitrification preservation method, the high concentrations of toxic penetrating cryoprotectant agents (CPA, up to 4.3 M) and low throughput (only one every experiment) put forward a challenge. Here, we report a synergetic ice inhibition platform via PVA/Fe3O4/GO nanoparticles (PFG NPs), that achieves sharp ice morphology, ice recrystallization, and devitrification inhibition, thus reducing cryodamage both in cooling and warming stages. Oocyte cryopreservation experiment demonstrates the survival rate can attain 98.6% using 2.5 M penetrating CPA while ensuring the scalability (ten oocytes each cryopreservation procedure). In contrast, recovered oocytes via PFG platform show 85 gene variation compared with fresh oocytes, whereas tradition CPA (TCPA) formulation induces 1396 gene changes. Meanwhile, the PFG-cryopreservation oocytes maintain normal ability of fertilization, development, and birth of offspring.
Project description:ObjectiveTo determine whether optimal human spermatogonial stem cell (SSC) cryopreservation is best achieved with testicular tissue or single cell suspension cryopreservation. This study compares the effectiveness between these two approaches by using testicular SSEA-4+ cells, a known population containing SSCs.DesignIn vitro human testicular tissues.SettingAcademic research unit.Patient(s)Adult testicular tissues (n=4) collected from subjects with normal spermatogenesis and normal fetal testicular tissues (n=3).Intervention(s)Testicular tissue versus single cell suspension cryopreservation.Main outcome measure(s)Cell viability, total cell recovery per milligram of tissue, as well as viable and SSEA-4+ cell recovery.Result(s)Single cell suspension cryopreservation yielded higher recovery of SSEA-4+ cells enriched in adult SSCs, whereas fetal SSEA-4+ cell recovery was similar between testicular tissue and single cell suspension cryopreservation.Conclusion(s)Adult and fetal human SSEA-4+ populations exhibited differential sensitivity to cryopreservation based on whether they were cryopreserved in situ as testicular tissues or as single cells. Thus, optimal preservation of human SSCs depends on the patient's age, type of samples cryopreserved, and end points of therapeutic applications.