The expression and significance of CATSPER1 in human testis and ejaculated spermatozoa

Aim： To investigate the distribution of cation channel of sperm 1 （CATSPER1） protein and the presence of CATSPER1 mRNA in human testis and ejaculated spermatozoa. The influence of anti-human CATSPER1 antibody upon human sperm motility was used to evaluate the function of human CATSPER1 and to estimate its possible use as a target for immunocontraception. Methods： Human ejaculated sperm from normozoospermic donors （n = 12） and liquid nitrogen frozen human testis were used for the study of mRNA and protein expression of CATSPER1 by reverse transcription polymerase chain reaction （RT-PCR） and immunohistochemistry, respectively. Spermatozoa from normozoospermic donors （n = 12） were individually processed using a swim-up procedure and were then incubated with CATSPER1 antibody at final concentrations of 20, 4 and 0.8 μg/mL. After 1, 2 and 6 h incubation, progressive motility and fast progressive motility were measured by means of computer-assisted semen analysis. Results： CATSPER1 transcript was detected in both human testis and each human ejaculated semen sample. CATSPER1 protein expressed in the membrane of spermatid and was localized in the principal piece of the sperm tail. The application of CATSPER1 antibody at all concentrations significantly inhibited both progressive motility and fast progressive motility after 1, 2 and 6 h incubation, and significant dose-dependent changes were observed. Conclusion： CATSPER1 is meiotically and post-meiotically expressed in human testis tissue. CATSPER1 mRNA in human ejaculated spermatozoa could be a more feasible target for study and infertility screening than testis biopsy. In addition, our results suggest that human CATSPER1 could be a possible target for immunocontraception.

Immuno-contraceptive potential of sperm specific LDHC₄and SPAM-1 (PH-20) sub units in dog

PH-20 (Spam-1) antigen appears to be a bi-functional sperm plasma membrane protein with hyaluronidase activity and its role is related to cumulus penetration as well as zona binding. (LDH-C4) is a key enzyme, distributed specifically in testis and is highly immunogenic, function of which relates to energy metabolism and capacitation of the sperm. Therefore, in this study, we observed the effect of purified native PH-20 and LDH-C4 antigens on sperm function and morphology in dog. Native PH-20 (46, 32 kDa) and LDH-C4 (36, 30, 28) sub units, purified from dog sperm SDS- extracts were used to test as immunocontraceptive candidates in stray dog. Dogs 1, 2, 3, 4, 5/6 and 7/8 were immunized with 46, 32, 36, 30/28, 46/32, 36/30/28 kDa sub units respectively by i/m route and semen was analysed at weekly intervals. High titre of 3200 - 6400 was achieved in all dogs after three boosters. Immune response in treated dogs was confirmed by increase in Ig level in blood serum and reaction of partially purified serum Ig of immunized dogs with respective antigens in double immune diffusion and immunoblots. Immunization of dogs either with individual PH-20/ LDHC sub units or pooled PH-20/LDHC4 sub units showed a significant effect on sperm count, percent motility, viability, HOST and sperm morphology. All the sperm parameters declined to a significant level (p < 0.05) between 45 - 115 DPI and remained low than that of the recommended values for fertile dog semen till 175 DPI. The incubation of spermatozoa in HOS solution in the presence of anti-PH-20 and anti-LDHC Ig significantly reduced the percent HOS positive spermatozoa. A significant decline (p ≤ 0.05) in acrylamide penetration assay was also observed in the presence of anti 46 and 30/28 kDa Ig. Since percent motility, sperm count, HOST and percent normal spermatozoa in immunized dogs were significantly less than that of recommended fertile dog semen, it can be concluded that PH-20 (46/32 kDa) and LDHC4 (36/30/28 kDa) sub units had an immunocontraceptive potential in dog.

The expression and significance of CATSPER1 in human testis and ejaculated spermatozoa

Aim:To investigate the distribution of cation channel of sperm 1(CATSPER1)protein and the presence of CATSPER1 mRNA in human testis and ejaculated spermatozoa.The influence of anti-human CATSPER1 antibody upon human sperm motility was used to evaluate the function of human CATSPER1 and to estimate its possible use as a target for immunocontraception.Methods:Human ejaculated sperm from normozoospermic donors(n=12)and liquid nitro- gen frozen human testis were used for the study of mRNA and protein expression of CATSPER1 by reverse transcliption polymerase chain reaction(RT-PCR)and immunohistochemistry,respectively.Spermatozoa from nonnozoospermic donors(n=12)were individually processed using a swim-up procedure and were then incubated with CATSPER 1 antibody at final concentrations of 20,4 and 0.8μg/mL.After 1,2 and 6h incubation,progressive motility and fast progressive motility were measured by means of computer-assisted semen analysis.Results:CATSPER1 transcript was detected in both human testis and each human ejaculated semen sample.CATSPER1 protein expressed in the membrane of spermatid and was localized in the principal piece of the sperm tail.The application of CATSPER1 antibody at all concentrations significantly inhibited both progressive motility and fast progressive motility after 1,2 and 6h incubation,and significant dose-dependent changes were observed.Conclusion:CATSPER1 is meiotically and post-meiotically expressed in human testis tissue.CATSPER1 mRNA in human ejaculated spermatozoa could be a more feasible target for study and infertility screening than testis biopsy.In addition,our results suggest that human CATSPER1 could be a possible target for immunocontraception.(Asian J Androl 2006 May:8:301-306)