Effects of zinc on expression of apoptosis-related genes in freezing thawing damage of adipose tissue derived mesenchymal stromal cells.

The present study was performed to investigate the effects of zinc supplementation on freezing thawing damage in adipose tissue-derived mesenchymal stromal cells (MSC) of mice through studying cellular viability and gene expression profile of apoptosis. Slow freezing method was conducted and the samples were treated with zinc doses 0, 2.5, 5, 10, 25, 50 and 100 µM. Viability was increased in groups of 2.5, 10 and 25 µM zinc in comparison to the control group. Gene expression study showed that in the group of 2.5 µM zinc, Fas, Bax and Caspase3 had down regulation. Up regulation of Bcl2 was observed in the groups of 10 and 25 µM zinc. P53 did not have a protecting regulation in the groups of study. The present study showed that doses 2.5-25 µM of zinc had a rather safe toxicity, increased cellular viability, and ameliorated expression of apoptosis-related genes in both intrinsic and extrinsic pathways.

Effect of Selenium on Expression of Apoptosis-Related Genes in Cryomedia of Mice Ovary after Vitrification.

INTRODUCTION: Freezing of ovarian tissue is used for preservation of fertility. The freezing-thawing process is accompanied by oxidative stress and induction of apoptosis. Apoptosis is a complex process that has been studied in animal models. The present study was aimed at investigating the effect of selenium on suppression of apoptosis during vitrification-thawing process of mice ovary via studying expression of apoptosis-related genes, and also, we aimed to design statistical models for the roles of single genes and gene-gene interactions in suppression of apoptosis. METHODS: A total of 10 right ovary samples from 10 mice were randomly divided into two groups of selenium treatment (at dose 5 µg/ml sodium selenite, through adding to the media) and control group. Vitrification-thawing process was done according to the existed protocols. Real-time PCR was used for gene expression study. The apoptosis gene profile included P53, Bax, Fas, and Bcl-2. General linear model was applied to study single gene associations and gene-gene interactions. RESULTS: From the studied genes, P53 showed a significant downregulation in the selenium group in comparison to the control group (∆∆CT = 1.96; P = 0.013; relative expression (RE) = 0.28). Bcl-2 showed a significant upregulation in the selenium group in comparison to the control group (∆∆CT = -2.49; P < 0.001; RE = 3.49). No significant result was found for other genes. According to the multiple models, Bcl-2 showed a protective single gene association (beta = -0.33; P = 0.032), and Fas∗Bcl-2 interaction was significantly positive (beta = 0.19; P = 0.036). CONCLUSION: Addition of selenium to cryomedia of vitrification-thawing process could reduce the apoptosis induced by freezing-thawing stress in mice ovary via downregulation of P53 and upregulation of Bcl-2 at transcription level. Multivariable statistical models should be performed in future researches to study biological systems.

Ultrastructural changes of corpus luteum after ovarian stimulation at implantation period.

BACKGROUND: To achieve multiple oocytes for in vitro fertilization, ovulation induction is induced by gonadotropins; however, it has several effects on oocytes and embryo quality and endometrium receptivity. The aim of this study was to assess ultrastructural changes of corpus luteum after ovarian induction using human menopausal gonadotropin (HMG) and human chorionic gonadotropin (HCG) during luteal phase at implantation period. METHODS: Female NMRI mice (6-8 weeks) were divided into control and stimulated groups. In the control group, the mice were rendered pseudopregnant and in the ovarian induction group, the mice were rendered pseudopregnant after the ovarian induction. The samples were obtained from the ovary in each group at the same time during luteal phase at implantation period. Ultrastructural changes were assessed using electron microscopy study. RESULTS: Our results displayed some identifiable changes in ultrastructure of corpus luteum in ovarian induction group. These changes included enhancement of the apoptosis and intercellular space, whereas the angiogenesis was decreased. The findings indicated a decline in organelle density in the cytoplasm of ovarian induction, such as mitochondria, endoplasmic reticulum and polyribosome. Furthermore, chromatin condensation of nuclei was observed in some cells. CONCLUSION: The ovarian induction using HMG and HCG resulted in some ultrastructural changes on the corpus luteum at implantation period, which could affect on the pregnancy rate.