Stem cell based therapeutical approach of male infertility by teratocarcinoma derived germ cells

Abstract

Infertility affects 13-18% of couples and growing evidence from clinical and epidemiological studies suggests an increasing incidence of male reproductive problems. There is a male factor involved in up to half of all infertile couples. The pathogenesis of male infertility can be reflected by defective spermatogenesis due to failure in germ cell proliferation and differentiation. We report here in vitro generation of a germ cell line (SSC1) from the pluripotent teratocarcinoma cells by a novel promoter-based sequential selection strategy and show that the SSC1 cell line form mature seminiferous tubule structures, and support spermatogenesis after transplantation into recipient testes. To select differentiated germ cell population, we generated a fusion construct (Stra8-EGFP) harbouring the 1.4 kb promoter region of germ line specific gene Stra8 and coding region of enhanced green fluorescence protein. This region was sufficient to direct gene expression to the germinal stem cells in testis of transgenic mice. The purified cells expressed the known molecular markers of spermatogonia Rbm, cyclin A2, Tex18, Stra8 and Dazl and the beta1- and alpha6-integrins characteristic of the stem cell fraction. This cell line undergoes meiosis and can develop into sperm when transplanted into germ cell depleted testicular tubules. Sperm were viable and functional, as shown by fertilization after intra-cytoplasmic injection into mouse oocytes. This approach provides the basis that is essential for studying the development and differentiation of male germ line stem cell, as well as for developing new approaches to reproductive engineering and infertility treatment.

Alteration in genes expression patterns during in vitro differentiation of mouse spermatogonial cells into neuroepithelial-like cells

“…In fact, RA receptors are found in different tissues, in particular in the nervous system and their numbers increase at the time of neural differentiation (Maden et al 1998). Our result confirmed previous studies showed that RA induced neural differentiation in both ESC-and ESlike cells (Maden et al 1998;Nayernia 2004).…”

“…Generating ES-like cells from testis is useful in cell line production from a specific patient and can produce sufficient cells for regenerative therapy (Nayernia 2004). New research has shown the derivation of pluripotent stem cells from neonatal and adult mouse testis that can differentiate to all cell types (Guan et al 2007;Nayernia 2007).…”

“…The applicability of spermatogonial stem cells to be used for individual cell therapy without ethical problem, make them more applicable for cell transplantation than ES cells (Nayernia 2004). These characteristics propose the therapeutic use of spermatogonial stem cells in regenerative medicine especially as a new and unlimited source for neurodegenerative disease treatment and may represent a possible alternative to replace neurons and glia.…”

“…Differentiation of spermatogonial stem cells into neuroepithelial-like cells (neuro-glial progenitor cells are capable of giving rise to both differentiated neuronal and glial cells) is an important step in cell therapy for patients suffering from neurodegenerative diseases (Nayernia 2004).…”

“…Spermatogonial stem cells can form embryonic stem-like cells (ES-like cells) and embryoid body structure in vitro that can differentiate to three germ layers (Nayernia 2004;Damjanov 1982).…”