Rat Epididymis Specific The Gene Lcn6 Expression Features And Functionality,

Lipocalins are a large and diverse group of small, mostly extracellular proteins that are found in vertebrates and invertebrate animals, plants, and bacteria. Although they have been classified mainly as transport proteins, it is now clear that members of the lipocalin family fulfill a wide variety of different functions, such as the modulation of cell growth and metabolism, the regulation of the immune response, smell reception, tissue development and animal behavior. Recently, numerous members of lipocalin family have been identified in epididymis and their involvement in sperm maturation was highlighted by reports describing the spermatozoon-association of Lcn5, Lcn2, mEP17, PGDS and human LCN6. Our research focused on rat Lcn6, which is a member of a gene cluster that includes Lcn8 and Lcn5 in a lipocalin-rich region of chromosome 3p13. Lcn6 gene contains 7 exons and 6 introns. The exons encode 181 amino acids including a 24- amino acid signal peptide. Like its homologue in human, rat Lcn6 mRNA and protein were specifically expressed in distal efferent ducts, initial segment and proximal caput. Lcn6 mRNA can not be detected by real time RT-PCR until the rat is 3 weeks old. The level of Lcn6 mRNA begins to increase greatly during the period of 3 weeks old to 12 weeks old. Then, the Lcn6 mRNA will hold on a constant level. Lcn6 protein is synthesized in most of the principle cells in the initial segment and it can be secreted into the lumen of epididymis. Lcn6 can interact with spermatozoa and its presence on the middle piece and acrosomal area of sperm can be detected in the initial segment. But when the sperm swims into the caput region, Lcn6 disappears on the middle piece of sperm and can be only detected in the acrosomal area. The interaction between Lcn6 and sperm means that Lcn6 may be involved in the sperm maturation. To confirm this point, we used Lentivirus-based RNAi technology to down-regulate the expression of Lcn6 in vivo and then analyze the sperm motility by CASA. The sperm motility and progressive motility were greatly attenuated when the Lcn6 was knocked down. This result showed that Lcn6was very important for sperm motility.We also did some research on the therapeutic use of RNAi technology and antisense technology. We have ever designed 26 antisense oligodeoxynucleotides and 26 siRNA duplexes targeting SARS-CoV's structure protein E, M and N. We examined their effect in Vero E6 cells and got 6 antisense oligodeoxynucleotides and 3 siRNA duplexes which could reduce SARS-CoV genes expression effectively. We also did some research on the therapy of HBV related diseases, Liver cancer, liver fibrosis, keloid and schistosome etc. by the use of RNAi technology. Our research proved that RNAi might provide an effective therapeutic strategy for many diseases.