Characterization of spermatogonial stem cells lacking intercellular bridges and genetic replacement of a mutation in spermatogonial stem cells.
Stem cells have a potential of gene therapy for regenerative medicine. Among various stem cells, spermatogonial stem cells have a unique characteristic in which neighboring cells can be connected by intercellular bridges. However, the roles of intercellular bridges for stem cell self-renewal, differentiation, and proliferation remain to be elucidated. Here, we show not only the characteristics of testis-expressed gene 14 (TEX14) null spermatogonial stem cells lacking intercellular bridges but also a trial application of genetic correction of a mutation in spermatogonial stem cells as a model for future gene therapy. In TEX14 null testes, some genes important for undifferentiated spermatogonia as well as some differentiation-related genes were activated. TEX14 null spermatogonial stem cells, surprisingly, could form chain-like structures even though they do not form stable intercellular bridges. TEX14 null spermatogonial stem cells in culture possessed both characteristics of undifferentiated and differentiated spermatogonia. Long-term culture of TEX14 null spermatogonial stem cells could not be established likely secondary to up-regulation of CDK4 inhibitors and down-regulation of cyclin E. These results suggest that intercellular bridges are essential for both maintenance of spermatogonial stem cells and their proliferation. Lastly, a mutation in Tex14(+/-) spermatogonial stem cells was successfully replaced by homologous recombination in vitro. Our study provides a therapeutic potential of spermatogonial stem cells for reproductive medicine if they can be cultured long-term.
Department of Pathology & Immunology, Baylor College of Medicine, Houston, Texas, United States of America. iwamori@bcm.tmc.edu
Naoki
N
Iwamori
Tokuko
T
Iwamori
Martin M
MM
Matzuk
D000818:Animals; D001483:Base Sequence; D002469:Cell Separation; D017931:DNA Primers; D006579:Heterozygote; D008297:Male; D051379:Mice; D009154:Mutation; D060888:Real-Time Polymerase Chain Reaction; D011995:Recombination, Genetic; D013093:Spermatogonia / Q000166:cytology*; D013234:Stem Cells / Q000166:cytology*; D013737:Testis / Q000166:cytology; D014157:Transcription Factors / Q000235:genetics*
D017931:DNA Primers; C510086:TEX14 protein, mouse; D014157:Transcription Factors