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Maki C.,PrimeGen Biotech | Howerton K.,PrimeGen Biotech | Pacchiarotti J.,PrimeGen Biotech | Ramos T.,PrimeGen Biotech | And 9 more authors.
Journal of Neurodegeneration and Regeneration | Year: 2010

Objective: The aim of this study was to investigate the ability of the adult spermatogonial stem cells (SSCs) to differentiate into the dopaminergic lineage. Design: First, a mixture of testicular cells were aggregated to form embryoid bodies and then cultured on the PA6 cells (stromal cell line) in the presence of growth factors. Second, enriched populations of SSCs were sorted by Stage-specific embryonic antigen-4 and cultured on the mouse embryonic fibroblasts in the presence of growth factors. Results: In both conditions, structures with the morphology of neural trunks were formed. These trunks were extended and branched in time, which eventually made a network. Immunohistochemical localization and reverse transcription polymerase chain reaction analyses revealed that the trunks were positive for dopamine-specific markers. Conclusions: These results clearly show that SSCs from adult primate testes have the ability to differentiate into neural trunks with dopaminergic characteristics, suggesting that SSCs can be considered as an alternative cell source for cell replacement therapy of Parkinson's disease. Source


Izadyar F.,PrimeGen Biotech LLC | Wong J.,PrimeGen Biotech LLC | Maki C.,PrimeGen Biotech LLC | Pacchiarotti J.,PrimeGen Biotech LLC | And 11 more authors.
Human Reproduction | Year: 2011

BACKGROUND: This study was conducted to identify and characterize repopulating spermatogonial stem cells (SSCs) in the adult human testes. Methods Testes biopsies from obstructive azoospermic patients and normal segments of human testicular tissue were used. Flow cytometry, real-time PCR and immunohistochemical analysis were performed. Purified human spermatogonia were transplanted into busulfan-treated recipient mouse testes and integrated cells were detected by human nuclear protein antibody co-localized with stem cell and germ cell markers. Results Testicular biopsies collected from obstructive azoospermic men showed similar morphology and distribution of markers to the normal human testes. Flow cytometry showed distinct populations of stage-specific embryonic antigen-4 (SSEA-4), CD49f and CD90 positive cells in the adult human testes. SSEA-4 (+) cells showed high expression levels of SSC-specific genes and high levels of telomerase activity. Extensive colonization of human cells in the mouse testes indicates the presence of highly enriched populations of SSCs in the SSEA-4 (+) sorted cells. All the HNP (+) cells in the mouse testes were positive for germ cell marker dead box mRNA helicase and only half of them were dimly positive for c-kit. In addition, subpopulations of human spermatogonia that colonized mouse testes were positively stained for CD49f, GPR-125, Nanog and Oct-4 indicating the existence of population of cells among human spermatogonia with SSC and pluripotent characteristics. CONCLUSIONS This study clearly demonstrates that repopulating human SSCs have phenotypic characteristics of SSEA-4+, CD49f +, GPR-125+and c-Kit neg/low. The results have direct implications for enrichment of human spermatogonia for further culture and germ cell differentiation studies. © The Author 2011. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. Source

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