Isolation, Culture and Characterization of Klinefelter Spermatogonial Stem Cells
[eng] INTRODUCTION: Klinefelter syndrome (KS) is a chromosomal abnormality that affects approximately 1 in 500-1000 male births. Their most frequent karyotype is 47XXY and up to 10% of them present significant mosaicism in the study of peripheral blood. In most cases, KS patients remain asymptomatic...
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| Tipo de recurso: | tesis doctoral |
| Estado: | Versión publicada |
| Fecha de publicación: | 2023 |
| País: | España |
| Institución: | Universidad de Barcelona |
| Repositorio: | Dipòsit Digital de la UB |
| OAI Identifier: | oai:diposit.ub.edu:2445/222157 |
| Acceso en línea: | https://hdl.handle.net/2445/222157 http://hdl.handle.net/10803/694842 |
| Access Level: | acceso abierto |
| Palabra clave: | Esterilitat masculina Espermatogènesi Cèl·lules mare Síndrome de Klinefelter Male sterility Spermatogenesis Stem cells Klinefelter’s syndrome |
| Sumario: | [eng] INTRODUCTION: Klinefelter syndrome (KS) is a chromosomal abnormality that affects approximately 1 in 500-1000 male births. Their most frequent karyotype is 47XXY and up to 10% of them present significant mosaicism in the study of peripheral blood. In most cases, KS patients remain asymptomatic until adulthood when male infertility leads to diagnosis. A progressive loss of germ cells has been described that accelerates during puberty until extensive testicular fibrosis is established, leaving more than 90% of patients azoospermic. According to the current literature, approximately 8% of KS patients have functional spermatozoa in the ejaculate, resulting in healthy euploid offspring through natural conception or advanced fertility therapies. In azoospermic KS patients, isolated foci of testicular tissue with preserved spermatogenesis have been described, so testicular biopsy has been established as the treatment of choice. However, the success rate for sperm extraction in KS patients remains below 50% and the chances of achieving a healthy newborn are around 15%. Even in KS patients without viable spermatozoa in testicular biopsy, the pathological analysis of the samples has described the presence of undifferentiated spermatogonia. Spermatogonial stem cells (SSCs) are a small population of especially undifferentiated spermatogonia present in the basement membrane of the seminiferous tubules. SSCs have both the capacity for self-renewal as well as for differentiation towards spermatogenesis, maintaining the balance of the seminiferous tubules. In turn, the most characteristic quality attributed to SSCs is the ability to migrate to the basement membrane of seminiferous tubules of azoospermic subjects and reestablish spermatogenesis. It has been postulated that SSCs could be used in new experimental fertility therapies for KS patients without sperm available in testicular biopsies. This new generation of experimental advanced fertility techniques includes: SSC transplantation, in vitro spermatogenesis, ex vivo maturation of testicular tissue, and testicular tissue grafting. All of them have shown promising results in animal models as well as in preclinical studies and are at different levels of development towards clinical applicability. An essential aspect of any fertility treatment is the value of using the patient's autologous material in order to pass on their genetic material to their offspring. Most of the previously mentioned experimental SSC-based therapies require a significant number of cells to be viable. Some researchers have managed to propagate in vitro euploid testicular cells from rodents and humans while maintaining the characteristics of a putative SSC population. However, it is unknown whether these techniques would be reproducible in aneuploid subjects such as KS. HYPOTHESIS: Our hypothesis is that current methods of in vitro isolation and propagation of testicular cells could be adapted to the specific needs of testicular tissue of mice and humans with KS. Testicular organoids formed from testicular SK cells could provide insight into the pathophysiology of KS. Testicular organoids could also be a step towards new fertility therapies for KS patients. OBJECTIVES: 1. To isolate, propagate, and characterize testicular cells from XXY mice, including a population of putative SSCs. 2. Isolate, propagate, and characterize testicular cells from XXY humans, including a population of putative SSCs. 3. Forming 3D testicular organoids from XXY human testicular cells and assessing their potential as a SK model in vitro and as a tool for the spermatogenesis in vitro. |
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