ITGA6+ Human Testicular Cell Populations Acquire a Mesenchymal Rather than Germ Cell Transcriptional Signature during Long-Term Culture

• Published in: International journal of molecular sciences 2020-11, Vol.21 (21), p.8269
• Main Authors: Struijk, Robert B, Mulder, Callista L, van Daalen, Saskia K M, de Winter-Korver, Cindy M, Jongejan, Aldo, Repping, Sjoerd, van Pelt, Ans M M
• Format: Article
• Language: English
• Subjects: Biomarkers - metabolism; bulk transcriptome; cell culture; Cell Culture Techniques - methods; Cell Differentiation - genetics; Cell Proliferation - genetics; Cell Separation; Cells, Cultured; fertility preservation; germ cells; Humans; Integrin alpha6 - metabolism; Leydig Cells - metabolism; Male; Mesenchymal Stem Cells - cytology; Mesenchymal Stem Cells - metabolism; Spermatogenesis - genetics; spermatogonia; Spermatogonia - cytology; Spermatogonia - metabolism; stem cells; Testis - cytology; Testis - metabolism; Time Factors; Transcriptome
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms21218269

Autologous spermatogonial stem cell transplantation is an experimental technique aimed at restoring fertility in infertile men. Although effective in animal models, in vitro propagation of human spermatogonia prior to transplantation has proven to be difficult. A major limiting factor is endogenous somatic testicular cell overgrowth during long-term culture. This makes the culture both inefficient and necessitates highly specific cell sorting strategies in order to enrich cultured germ cell fractions prior to transplantation. Here, we employed RNA-Seq to determine cell type composition in sorted integrin alpha-6 (ITGA6+) primary human testicular cells ( = 4 donors) cultured for up to two months, using differential gene expression and cell deconvolution analyses. Our data and analyses reveal that long-term cultured ITGA6+ testicular cells are composed mainly of cells expressing markers of peritubular myoid cells, (progenitor) Leydig cells, fibroblasts and mesenchymal stromal cells and only a limited percentage of spermatogonial cells as compared to their uncultured counterparts. These findings provide valuable insights into the cell type composition of cultured human ITGA6+ testicular cells during in vitro propagation and may serve as a basis for optimizing future cell sorting strategies as well as optimizing the current human testicular cell culture system for clinical use.