Expression And Regulation Of LCN-2 Gene In Male Mice Testis

Lipocalin 2(LCN-2), also known as neutrophil gelatinase associated lipocalin, is a lipophilic secreted glycoprotein which belong to the transporters. It is involved in a variety of biological functions in animals. This research established the models by developmental expression, cryptorchidism and busulfan treatment, respectively detected and analyzed the expression pattern and tissue distribution of the LCN-2 in the testis of male CD-1 mice by using the methods of situ hybridization, western blot and quantitative real-time PCR. This can help to understand the relationship of LCN-2 and the male reproduction and the regulating mechanism, which will provide the theoretical basis data for the further studying the functions of LCN-2 in mice reproductive development.In the developmental expression models, LCN-2 expression had not been found in one-day old, ten-day old and twenty-day old mice. While in thirty-day old, forty-day old, two-month old, four-month old, eight-month old and twelve-month old mice, LCN-2 expression could be detected, and situ hybridization showed that the expression level was highest in four-month old mice.As for cryptorchidism models, the mice testis becomed smaller. Histology detection showed that the seminiferous tubules were damaged, and the seminiferous epithelium and seminiferous tubules had been degradation in different degrees, which had only a few of spermatogonia. LCN-2 m RNA expression was increased significantly, and most were expressed in Leydig cells(P=0.0378). Western blot detection also showed the protein levels were significantly increased(P=0.0005).While in the busulfan models, the mice testis was significantly smaller, with the severely damaged seminiferous tubules, leaving only a thin layer of seminiferous epithelium cell and almost no sperm cells in a lumen. Situ hybridization analysis showed that LCN-2 m RNA expression level was increased obviously(P=0.0232). The results from western blot detection were similar to the cryptorchidism models(P=0.0004).The results of Quantitative real-time PCR showed that the expression of LCN-2 has markedly increased in cryptorchidism and busulfan groups comparing to control group, which was consistented with the results of in situ hybridization.In summary, LCN-2 gene had been found in testis of male mice, and had difference based on different age. The expression level of LCN-2 had markedly upregulated in cryptorchidism and busulfan groups, which was indicated that azoospermia model can induce the expression of LCN-2. LCN-2 gene may be involved in spermatogenesis, differentiation and apoptosis of germ cell. All above provided a new research direction about male infertility, orchitis and reproductive dysfunction disease, and provided theoretical basis for the treatment of male infertility patients.