Advances in cryopreservation of spermatogonial stem cells and restoration of male fertility: ADVANCES IN CRYOPRESERVATION OF SSCS AND RESTORATION OF MALE FERTILITY

Therapeutic potential of bone marrow mesenchymal stem cells in cyclophosphamide-induced infertility

Cancer is a deadly disease characterized by abnormal cell proliferation. Chemotherapy is one technique of cancer treatment. Cyclophosphamide (CYP) is the most powerful chemotherapy medication, yet it has serious adverse effects. It is an antimitotic medicine that regulates cell proliferation and primarily targets quickly dividing cells, and it has been related to varying levels of infertility in humans. In the current study, we assessed the biochemical, histological, and microscopic evaluations of testicular damage following cyclophosphamide administration. Further, we have explored the potential protective impact of mesenchymal stem cell (MSCs) transplantation. The biochemical results revealed that administration of cyclophosphamide increased serum concentrations of follicle-stimulating hormone (FSH) and luteinizing hormone (LH), while it decreased serum concentrations of free testosterone hormone (TH), testicular follicle-stimulating hormone, luteinizing hormone, and free testosterone hormone concentrations, testicular total antioxidant capacity (TAC), and testicular activity of superoxide dismutase (SOD) enzyme. The histology and sperm examinations revealed that cyclophosphamide induced destruction to the architectures of several tissues in the testes, which drastically reduced the Johnsen score as well as the spermatogenesis process. Surprisingly, transplantation of mesenchymal stem cell after cyclophosphamide administration altered the deterioration effect of cyclophosphamide injury on the testicular tissues, as demonstrated by biochemical and histological analysis. Our results indicated alleviation of serum and testicular sex hormones, as well as testicular oxidative stress markers (total antioxidant capacity and superoxide dismutase activity), and nearly restored the normal appearance of the testicular tissues, Johnsen score, and spermatogenesis process. In conclusion, our work emphasizes the protective pharmacological use of mesenchymal stem cell to mitigate the effects of cyclophosphamide on testicular tissues that impair the spermatogenesis process following chemotherapy. These findings indicate that transferring mesenchymal stem cell to chemotherapy patients could significantly improve spermatogenesis.

Solid surface vitrification of goat testicular cell suspension enriched for spermatogonial stem cells

This study reports solid surface vitrification (SSV) of goat testicular cell suspensions (TCS) enriched for spermatogonial stem cells (SSCs). The TCS was isolated from pre-pubertal goat testis by enzymatic digestion, enriched for SSCs by filtration and differential plating, and were vitrified-warmed by SSV. The study showed that SSV could successfully vitrify goat TCS although the percentage of live cells in the vitrified-warmed group was lower (74.8 ± 4.1%) than in non-vitrified control (80.6 ± 6.27%). The vitrified-warmed TCS formed putative SSC colonies upon their in vitro culture, but the colony size of vitrified-warmed cells (24.3 ± 1.8 μm) was smaller than those of non-vitrified warmed cells (58.4 ± 2.5 μm). Mitochondrial activity (0.40 vs. 0.38 A U.), population doubling time (33.45 ± 1.25 h vs. 31.86 ± 1.90 h), and the cell proliferation rate (0.72 ± 0.10 vs. 0.75 ± 0.11 per day) of total cells (including putative SSCs and other somatic cells) did not differ (p > 0.05) between control and SSV vitrified-warmed groups. However, during in vitro culture for 96 h, vitrified-warmed cells showed significantly lower (0.75 vs. 1.33 A U.; p < 0.05) mitochondrial activity than non-vitrified controls. The DCFDA assay showed that ROS activity was significantly (p < 0.05) higher in vitrified-warmed cells (52.8 ± 4.1 A U) than non-vitrified control cells (32.8 ± 2.1 AU). In conclusion, our results suggest that SSC-enriched goat TCS could be successfully cryopreserved by SSV. However, ROS-induced damages to cell cytoplasmic components reduce their cellular proliferation and require further improvement in the protocol. To the best of our knowledge, this study is the first report on the SSV of SSC-enriched goat TCS.

Effect of miR-30a-5p on Apoptosis, Colonization, and Oxidative Stress Variables in Frozen-Thawed Neonatal Mice Spermatogonial Stem Cells

Cryopreservation of spermatogonial stem cells (SSCs) is a useful method for fertility preservation in preadolescent children suffering from cancer. However, SSCs may become damaged during cryopreservation due to the generation of reactive oxygen species (ROS). For this reason, various antioxidant agents have been used to protect SSCs from cryopreservation-induced damages. Recently, it has been reported that miR-30a-5p has antiapoptotic and antioxidant activity. The aim of this study was to assess the antiapoptotic and antioxidant effects of miR-30a-5p mimics in frozen-thawed SSCs. To this end, SSCs were isolated from male BALB/C mice (3-6 days old) and cultivated for 14 days. After the detection of optimum concentration, a miR-30a-5p mimic or miR-30a-5p inhibitor with Lipofectamine was transfected into SSCs and, finally, the cell groups were frozen for 1 week. After thawing, different properties, including cell viability (using MTT), colonization of SSCs (number and diameter of colonies), ROS generation (using DCFH-DA assay), levels of malondialdehyde (MDA) and superoxide dismutase (SOD), and gene expression of Bcl-2 and BAXBax (using quantitative real-time PCR), were investigated. The transfection of SSCs with miR-30a-5p mimics before the freezing-thawing process significantly increased the viability, number, and diameter of SSCs colonies. Also, the miR-30a-5p mimic decreased the levels of ROS production and MDA, but it increased the SOD levels. Moreover, the miR-30a-5p mimic decreased BAX and increased Bcl-2 expression in frozen-thawed SSCs. The transfection of SSCs with the miR-30a-5p mimic can increase cell viability and antioxidant defense, and it can decrease apoptosis during the freezing-thawing process. If SSC is able to produce spermatozoa after the transfection of miR-30a-5p and the freezing-thawing process, it can be suggested as a promising strategy for the cryopreservation of SSCs in prepubertal boys suffering from cancer.

Effect of selenium on freezing-thawing damage of mice spermatogonial stem cell: a model to preserve fertility in childhood cancers

Background

During treatment of childhood cancers, fertility of boys may be affected. Therefore, freezing spermatogonial stem cell (SSC) is recommended. However, freezing-thawing process may cause damage to SSCs. This study was conducted to evaluate protective effects of selenium on freezing-thawing damage of mice SSCs using investigation of cell viability and investigation of apoptosis related genes expression including Fas, Caspase3, Bcl2, Bax and P53.

Methods

SSCs were extracted from 80 6-day-old mice. The SSCs were divided into four groups: cryopreservation along with selenium (low and high dose), vitrification along with selenium (low and high dose), cryopreservation control, and vitrification control. Trypan blue staining and real-time polymerase chain reaction (real-time PCR) were used to investigate cell viability and gene expression, respectively.

Result

Comparison of cell viability in the experimental groups did not show a significant association. Expression of Fas and Caspase3 was significantly lower in cryopreservation group with low-dose selenium. Expression of Bcl2 was significantly lower in cryopreservation group with high-dose selenium. Expression of Bax and Caspase3 was significantly lower in vitrification group with low-dose selenium, and expression of P53 was significantly upper. Expression of Bax and Fas was significantly lower in vitrification group with high-dose selenium, and expression of P53 was significantly upper (P<0.001).

Conclusions

Selenium had dose dependent effect on apoptosis related genes profile. The only evident effect was the effect of low-dose selenium in cryopreservation on inhibition of apoptosis via extrinsic pathway.

The Growth of Preantral Follicles and the Impact of Different Supplementations and Circumstances: A Review Study with Focus on Bovine and Human Preantral Follicles

One of the most important concerns cancer survivors face is fertility. Current treatment modalities often result in damage to the reproductive system. Different options have been proposed to preserve the fertility of affected women, and many attempts have been made to improve their chance of childbearing after therapy. Cryopreservation of ovarian tissue and follicles before the onset of cancer treatment and then either transplantation of ovarian tissue or culture of ovarian tissue and individual follicles in vitro is a commonly cited approach. Extensive research is being done to design an optimal condition for the culture of ovarian follicles. Improving follicle culture systems by understanding their actual growth needs might be a crucial step toward fertility preservation in cancer patients. This review article will try to provide a summary of the role of different factors and conditions on growth of human and bovine preantral follicles in vitro.

Improved Isolation, Proliferation, and Differentiation Capacity of Mouse Ovarian Putative Stem Cells

The recent discovery of ovarian stem cells in postnatal mammalian ovaries, also referred to as putative stem cells (PSCs), and their roles in mammalian fertility has challenged the long-existing theory that women are endowed with a certain number of germ cells. The rare amount of PSCs is the major limitation for utilizing them through different applications. Therefore, this study was conducted in six phases to find a way to increase the number of Fragilis- and mouse vasa homolog (MVH)-positive sorted cells from 14-day-old NMRI strain mice. Results showed that there is a population of Fragilis- and MVH-positive cells with pluripotent stem cell characteristics, which can be isolated and expanded for months in vitro. PSCs increase their proliferation capacity under the influence of some mitogenic agents, and our results showed that different doses of stem cell factor (SCF) induce PSC proliferation with the maximum increase observed at 50 ng/mL. SCF was also able to increase the number of Fragilis- and MVH-positive cells after sorting by magnetic-activated cell sorting and enhance colony formation efficiency in sorted cells. Differentiation capacity assay indicated that there is a basic level of spontaneous differentiation toward oocyte-like cells during 3 days of culture. However, relative gene expression was significantly higher in the follicle-stimulating hormone-treated groups, especially in the Fragilis- sorted PSCs. We suggest that higher number of PSCs provides us either a greater source of energy that can be injected into energy-impaired oocytes in women with a history of repeat IVF failure or a good source for research.

Effects of antioxidants, catalase and α-tocopherol on cell viability and oxidative stress variables in frozen-thawed mice spermatogonial stem cells

Cryopreservation of spermatogonial stem cells is considered as a useful procedure for preserving fertility in children with testis cancer. SSCs were isolated from testes mice, and then antioxidant was added to the freezing medium. The Bax expression level in antioxidant groups was significantly (P ≤ 0.05) lower than the control group and a significant rise of Bcl2 expression was detected in the antioxidant groups. ROS production with antioxidant was significantly lower compared with the control group. Cryopreservation with the addition of the antioxidants can help increase the number of SSCs and improve the quality and viability of these cells after cryopreservation.