Spermatogonia stem cells (SSCs), also named the male germline stem cells (mGSCs), which is located at the base of the seminiferous tubules of testis, is the basis for generating sperm steadily in male animals. Currently, there are some preliminary study on the self-renewal and differentiation of SSCs, but further mechanism, especially in large animals, has not been clearly understood. Ras/ERK1/2 pathway is widely distributed in multiple cells in vivo. It plays an important role in cell proliferation, differentiation and so on. However, the study on the function for the self-renewal of dairy goats SSCs has not been investigated. In this study, the dairy goat SSCs characterization were evaluated by semi-RT-PCR, alkaline phosphatase (AP) staining, and immunofluorescence staining. Then, Ras/ERK1/2 pathway was blocked by specific MEK1/2 inhibitor PD0325901. We analyzed the proliferation by cell number, cell growth curve, Brdu incorporation assay, and cell cycle analysis. The results showed that the proliferation was significantly inhibited by PD0325901. Cell apoptosis induced by blocking the Ras/ERK1/2 pathway was analyzed by TUNEL. The expression of ETV5 and BCL6B, the downstream gene of Ras/ERK1/2 pathway, was downregulated. This study suggest that the Ras/ERK1/2 pathway plays a critical role in maintaining the self-renewal of dairy goat SSCs via regulation of ETV5 and BCL6B. This study laid a foundation for insights into the mechanism of SSCs self-renewal comprehensively.
Zhiwei Niu, Liming Zheng, Siyu Wu, Hailong Mu, Fanglin Ma, Wencong Song, Haijing Zhu, Jiang Wu, Xin He and Jinlian Hua
Xue-Ying Zhang, Yi-Meng Xiong, Ya-Jing Tan, Li Wang, Rong Li, Yong Zhang, Xin-Mei Liu, Xian-Hua Lin, Li Jin, Yu-Ting Hu, Zhen-Hua Tang, Zheng-Mu Wu, Feng-Hua Yin, Zheng-Quan Wang, Ye Xiao, Jian-Zhong Sheng and He-Feng Huang
Fertilization failure often occurs during in vitro fertilization (IVF) cycles despite apparently normal sperm and oocytes. Accumulating evidence suggests that mitochondria play crucial roles in the regulation of sperm function and male fertility. 3-Nitrophthalic acid (3-NPA) can induce oxidative stress in mitochondria, and melatonin, as an antioxidant, can improve mitochondrial function by reducing mitochondrial oxidative stress. The role of sperm mitochondrial dysfunction in fertilization failure during IVF is unclear. The present study revealed that spermatozoa with low, or poor, fertilization rates had swollen mitochondria, increased mitochondria-derived ROS, and attenuated mitochondrial respiratory capacity. 3-NPA treatment enhanced mitochondrial dysfunction in sperm. Spermatozoa with poor fertilization rates, and spermatozoa treated with 3-NPA, had reduced penetration ability. The concentration of melatonin was decreased in semen samples with low and poor fertilization rates. Melatonin, not only decreased excessive mitochondria-derived ROS, but also ‘rescued’ the reduced penetration capacity of spermatozoa treated with 3-NPA. Taken together, the study suggested that mitochondria-derived ROS and mitochondrial respiratory capacity are independent bio-markers for sperm dysfunction, and melatonin may be useful in improving sperm quality and overall male fertility.