[NEK2 gene expression in mouse cryptorchidism model and its mechanism involved in apoptosis].

Objective: To observe the expression of NEK2 mRNA and protein in the cryptorchidism mice model, and to explore its role in apoptosis of testicular tissue. Methods: A mouse cryptorchid model was constructed, and the spermatids in the spermatic tubules were observed by HE staining. Apoptosis was detected by Tunel test, and expression of NEK2 mRNA and protein was detected by RT-PCR and immunohistochemistry, respectively. Results: After the mouse cryptorchidism model was successfully constructed, the HE staining results showed that the damage of spermatogonia cells, primary spermatocytes and sperm cells in the seminiferous tubules became more severe with time. The results of Tunel test showed that the number of apoptotic cells first increased and then decreased, 1, 3, 6, 9 and 15 d apoptotic cells were 3.67±2.08 (t=2, P=0.0412), 7.67±1.53 (t=6.325, P=0.003), 17.67±3.51 (t=7.906, P=0.001), 30.67±3.51 (t=14.072, P<0.001) and 14.33±3.21 (t=6.860, P=0.002). The results of immunohistochemistry showed that NEK2 protein was expressed in the nucleus and cytoplasm in normal testis and cryptorchidism. RT-PCR and immunohistochemistry showed that expression of NEK2 mRNA and protein gradually increased after modeling. After reaching the peak, the expression gradually decreased with time, and was significantly lower than the normal control group. Conclusion: The trend of NEK2 expression in cryptorchidism tissue is consistent with the trend of cell apoptosis in cryptorchidism tissue, suggesting that abnormal expression of NEK2 may affect the damage of sperm cells in the seminiferous tubules through apoptosis, leading to infertility in patients with cryptorchidism.

[Expression changes of aldehyde dehydrogenase 1A1 in rat cryptorchidism and normal testis].

Objective: To study the mRNA and protein expression of aldehyde dehydrogenase 1A1(ALDH1A1)in rat cryptorchidism and normal testis. Methods: We established the cryptorchidism model by flutamide and took normal testis as normal group.The testicular tissue samples were collected on 15 days, 45 days, and 90 days after birth respectively.The expression of ALDH1A1 in rat cryptorchidism and normal testis were investigated by real-time PCR, Western blot and immunohistochemisty intissue microarray. Results: The mRNA expression of ALDH1A1 in cryptorchidism group in infant, adolescent and adult period were 1.01±0.19, 1.60±0.32, 0.75±0.16, and 1.66±0.23, 0.52±0.08, 0.15±0.10 in normal group, respectively.The expression of ALDH1A1 in cryptorchidism group was significantly lower than that in normal group in infant period, but it was significantly higher than that in the normal group in adolescent and adult period(P<0.05). Conclusions: The expression of ALDH1A1 was different in different age period during the process of testicular development of rat. It showed an important relationship between ALDH1A1 and cryptorchidism.

Immunohistochemical and in-situ hybridization study of hypoxia inducible factor-1alpha and angiopoietin-1 in a rabbit model of mandibular distraction osteogenesis.

The endogenous release of angiogenic factors in a rabbit mandibular distraction osteogenesis model was investigated. The spatial and temporal expression of hypoxia inducible factor-1alpha (HIF-1alpha) and angiopoietin-1 (Ang-1) was compared at different phases. The lengthened calluses were harvested on post-osteotomy days 13, 20, 34 and 48, and then stained with haematoxylin & eosin. Immunohistochemical (IHC) and in-situ hybridization (ISH) examination of HIF-1alpha and Ang-1 staining was performed. The ossification in the distracted gap was predominantly intramembranous and slightly endochondral. Expression of HIF-1alpha and Ang-1 was mainly detected in the cytoplasm of fibroblast-like cells, osteoblasts and immature osteocytes on day 13 and 20, but declined with bone maturation. HIF-1alpha was also detected in the nuclei of some osteoblasts. These results suggest that the production of HIF-1alpha and Ang-1 in the distracted gap may contribute to new bone formation during gradual distraction of the mandible.