Assessment of sperm morphology, chromatin integrity, and catSper genes expression in hypothyroid mice

Abstract

There is an evident relationship between the fertilizing capacity of sperm and the normal morphology, quality chromatin, and motility of sperm. It is well known that thyroid hormones are the important regulators of testicular function. A correlation was found between the hypothyroidism and sperm damages. The present study was conducted to investigate the effects of hypothyroidism on sperm morphology, chromatin quality, and motility. For this purpose, 20 male mice were divided into the control and the hypothyroid groups that received 0.05% 6-n-propyl-2-thiouracil (PTU) for 35 days. Sperm morphology with Papanicolaou staining and sperm chromatin quality with both Aniline Blue (AB) and Toluidine blue (TB) staining were assessed. Besides, immunohistochemistry and real-time PCR were performed to evaluate the changes of cation sperm channel (CatSper) genes. A significant increase in the sperm chromatin condensation was found in the hypothyroid mice compared to the control mice (p < 0.05). Furthermore, a significant decrease was observed in the morphology of normal sperm in hypothyroid mice compared to the controls (p < 0.05). The results showed that Hypothyroidism could downregulate the expression of CatSper genes. Immunohistochemical data confirmed the real time-PCR results. Furthermore, the results showed that hypothyroidism could adversely affect sperm morphology, sperm chromatin condensation, and CatSper gene expression in mice and these abnormalities may be related to the excessive production of reactive oxygen species (ROS) in a hypothyroid state.

Effect of experimental hyperthyroidism on CatSper1 and CatSper2 genes expression in the seminiferous tubules of BALB/c mice: An experimental study

“…However, the results of this study on the effects of hyperthyroidism on the aforementioned factors did not show any significant differences in the experimental group compared to the control group. Therefore, it can be concluded that the decrease in thyroid hormone levels may affect the CATSPER1,2 gene and protein expression (25). In varicocele disease, sgnificant increase was observed in the CATSPER1,2 gene and protein expression in the experimental group compared to the control group, which did not match with the results of our research in terms of significance.…”

“…On the contrary, our results showed a reduction in staining intensity in the hyperthyroidism mice compared to that in the control group (24). Previous findings showed that in hypothyroid mice, hypothyroidism has an effect on the expression CATSPER1,2 gene and protein that results in significant difference between the experimental group and the control group (25). However, the results of this study on the effects of hyperthyroidism on the aforementioned factors did not show any significant differences in the experimental group compared to the control group.…”

Paternal Subclinical Hypothyroidism Affects the Clinical Outcomes ofIn VitroFertilization/Intracytoplasmic Sperm Injection

“…Aging is also recognized to be associated with more frequent germ cell and sperm DNA mutations (44) and excess reactive oxygen species (48); these pathologic alterations may affect male fertility. Interestingly, SCH was also reported to be associated with these above alterations, as reported in both human and animal models (33,49), indicating that aging may play an additive effect on SCH. This effect could account for the observed phenomenon that only differences in clinical outcomes (clinical pregnancy rate and implantation rate) in older men ( ‡35 years) were statistically significant.…”

“…First, animal studies have indicated that a hypothyroid state can affect sperm function (29). An increase in reactive oxygen species production was also observed in sperm isolated from hypothyroid animal models (33). As SCH reflects only a subtle deficiency in thyroid function, it is possible that SCH exerts mild effects on sperm function and the subsequent embryo development.…”

“…Second, DNA damage in sperm might be another critical factor that mediates poor SCHinduced ATR outcomes. Increased amounts of DNA damage were observed in the sperm of hypothyroid animal models (33,34). A higher DFI has also been associated with lower embryo cleavage rates (35), resulting in a reduced potential to develop into blastocysts (36) and a decreased clinical pregnancy rate (37).…”