The Viability of Human Testis-Derived Cells on Human Serum Albumin-Based Scaffold as An Artificial Male Germ Cell Niche

Favorable culture conditions for spermatogonial propagation in human and non-human primate primary testicular cell cultures: a systematic review and meta-analysis

Introduction: Autologous transplantation of spermatogonial stem cells (SSCs) isolated from cryopreserved testicular biopsies obtained before oncological treatment could restore fertility in male childhood cancer survivors. There is a clear necessity for in vitro propagation of the limited SSCs from the testicular biopsy prior to transplantation due to limited numbers of spermatogonia in a cryopreserved testicular biopsy. Still, there is no consensus regarding their optimal culture method. Methods: We performed a systematic review and meta-analysis of studies reporting primary testicular cell cultures of human and non-human primate origin through use of Pubmed, EMBASE, and Web of Science core collection databases. Of 760 records, we included 42 articles for qualitative and quantitative analysis. To quantify in vitro spermatogonial propagation, spermatogonial colony doubling time (CDT) was calculated, which measures the increase in the number of spermatogonial colonies over time. A generalized linear mixed model analysis was used to assess the statistical effect of various culture conditions on CDT. Results: Our analysis indicates decreased CDTs, indicating faster spermatogonial propagation in cultures with a low culture temperature (32°C); with use of non-cellular matrices; use of StemPro-34 medium instead of DMEM; use of Knockout Serum Replacement; and when omitting additional growth factors in the culture medium. Discussion: The use of various methods and markers to detect the presence of spermatogonia within the reported cultures could result in detection bias, thereby potentially influencing comparability between studies. However, through use of CDT in the quantitative analysis this bias was reduced. Our results provide insight into critical culture conditions to further optimize human spermatogonial propagation in vitro, and effectively propagate and utilize these cells in a future fertility restoration therapy and restore hope of biological fatherhood for childhood cancer survivors.

Recent advances in developing 3D culture systems of spermatogonial stem cell preservation and differentiation: A narrative review

Male infertility has received vast attention in recent years and has no clear etiology in almost 40% of cases. Several methods have been suggested for preserving sperm and spermatogonial stem cells (SSCs) in both in vivo and in vitro conditions. The efficacy of these methods is related to their abilities, including providing an optimal environment for sperm preservation and long-term SSC culture for in vivo and in vitro differentiation of these cells. In this review article, a full MEDLINE/PubMed search was performed using the following search terms: "Spermatogonial Progenitor Cells, Stem Cells, Fertility Preservations, Sperm Freezing, Cell Differentiations, Tissue Scaffold, 3-Dimensional Cell Culture", which retrieved results from 1973-2022. Related articles were added to the bibliography of selected articles. Exclusion criteria included non-English language, abstract only, and unrelated articles. The production of functioning male germ cells is suggested by introducing modern bioengineered systems as a new hope for the maintenance of male fertility. Till now, few in vitro spermatogenesis investigations have provided appreciable amounts of mature gametes. Each method had benefits and disadvantages, but the 3-dimensional culture method had the greatest impact on the differentiation and preservation of SSCs. One of the critical elements of research is the preservation of sperm and the differentiation of SSCs. Several methods have been employed in this area. Various scaffolds providing an environment similar to an extracellular matrix and conditions for germ cell development and survival have been employed in recent research.

Effect of Human Testicular Cells Conditioned Medium on In Vitro Maturation and Morphology of Mouse Oocytes

Background

Testicular cell conditioned medium (TCCM) has been shown to induce female germ cell development in vitro from embryonic stem cells (ESCs). Testicular cells (TCs) secrete a variety of growth factors such as growth differentiation factor-9 (GDF-9), bone morphogenetic protein 4 (BMP-4), stem cell factor (SCF), leukemia inhibitory factor (LIF), and other, that could improve oocyte maturation. Here we have investigated the effect of human TCCM (hTCCM) on in vitro maturation (IVM) and morphology of mouse oocytes.

Materials and Methods

In this experimental study, 360 germinal vesicle (GV) oocytes were obtained from NMRI mice, aged 4-6 weeks that had received 5 IU pregnant mare's serum gonadotropin (PMSG) 48 hours before. GV oocytes were subjected to IVM. 120 GV oocytes were cultured in each medium; hTCCM as the test group, DMEM + 20%FBS as the control group and Ham’s F10 + HFF medium as the sham group. The rates of the IVM and perivi- telline space (PVS) changes were recorded at 8, 16 and 24 hours after culture. The metaphase II (MII) oocytes were subjected for in vitro fertilization (IVF) and the fertilization rate was evaluated after 1, 2, and 3 days.

Results

There was a significant difference between the maturation rates in hTCCM (31.67% MII) and the control [0% MII, P<0.05, (7.5% MI, 52.5% deg. and 40%GV)] groups but there was not a significant difference between the maturation rates in hTCCM and the sham group (53.33% MII, P>0.05). IVF success rate for MII oocytes obtained from IVM in the hTCCM group was 28.94% (n=11). Our data showed that hTCCM is an effective medium for GV oocyte growth and maturation compared to the control medium.

Conclusion

Our findings show that TCCM supports oocyte IVM in mice and affect oocyte morphology.