Spermiogenesis is a dynamic process which includes organelle reorganization and new structure formation. The morphology and distribution of the mitochondria in germ cells change to accommodate the cellular requirement...Spermiogenesis is a dynamic process which includes organelle reorganization and new structure formation. The morphology and distribution of the mitochondria in germ cells change to accommodate the cellular requirement. Multiple molecular motors and related proteins participate in carrying and anchoring mitochondria to the midpiece during spermiogenesis and this process is regulated precisely. Energetic metabolism provides energy for cellular activity and influences sperm survival and motility directly. Ubiquitination of mitochondria takes place during spermiogenesis, which has been implicated in sperm quality control and mitochondrial inheritance. In light of the essential roles of mitochondria in energy production, calcium homeostasis and apoptosis, mitochondria dysfunction cause severe human diseases, such as male infertility. The present study paves a way for a more detailed exploration of the biology of mitochondria during spermiogenesis.展开更多
Aim： To investigate whether early apoptotic changes in spermatozoa can be significant markers for sperm quality. Methods： Two early apoptotic changes in the semen of 56 men were assessed using Annexin V （AN）/propi...Aim： To investigate whether early apoptotic changes in spermatozoa can be significant markers for sperm quality. Methods： Two early apoptotic changes in the semen of 56 men were assessed using Annexin V （AN）/propidium iodide （PI） staining for phosphatidylserine externalization and JC-1 staining for mitochondrial membrane potential （MMP）. The results were compared with conventional semen parameters and DNA fragmentation identified using the TUNEL assay. Results： The different labeling patterns in the bivariate Annexin V/PI analysis identified four distinctive spermatozoa populations. The percentage of AN^-/PI^- spermatozoa positively correlated with conventional semen parameters and MMP, but negatively correlated with TUNEL （＋） spermatozoa. As for the AN^-/PI^＋ fraction, we found an opposite result in comparison to AN^-/PI^- spermatozoa. The level of early apoptotic AN^＋/PI^- spermatozoa negatively correlated with MMP and sperm motility. The level of late apoptotic AN^＋/PI^＋ spermatozoa negatively correlated with conventional semen parameters and MMP, and positively correlated with TUNEL （＋） spermatozoa. MMP positively correlated with conventional semen parameters, but negatively correlated with TUNEL （＋） spermatozoa. Conclusion： Although early apoptotic AN^＋/PI^- spermatozoa only negatively correlates with sperm motility, the differences in proportion of each subpopulation of spermatozoa （especially, the percentage of AN^-/PI^- spermatozoa）, and decreased MMP might be significant markers for diagnosing male infertility. They possibly bring additional information to predict the outcome of in vitro fertilization. （Asian J Androl 2008 Mar; 10： 227-235）展开更多
Aim： To determine the short and long-term morphological effects on sperm as induced by intra-vas alteration of pH and electrical charge. Methods： Desired biophysical influences were obtained by injection of reversib...Aim： To determine the short and long-term morphological effects on sperm as induced by intra-vas alteration of pH and electrical charge. Methods： Desired biophysical influences were obtained by injection of reversible inhibition of sperm under guidance （RISUG） into the lumen of the vas deferens of human subjects and the monkey. RISUG is a polyelectrolyte hydrogel complex of styrene maleic anhydride （SMA） and dimethyl sulfoxide （DMSO） which generates an electrostatic charge and also lowers in a near space of pH domain. The morphology of sperm was examined by light microscopy, scanning and transmission electron microscopy. Human study enabled semen collection by masturbation as early as 3 h after injection and studies extended up to 6 months, in the monkey, on vas excision after RISUG implantation, sperm characteristics were examined in serial sections. Results： Semenology in clinical studies and histological data of the monkey showed a time-sequenced sperm plasma membrane, tail mitochondria and nuclear decondensation alterations in sperm structural components, which beared marked similarity to changes in the sperm head and tail during capacitation and entry into the ovum. Conclusion： The findings provide a means of causing such changes in the sperm that inhibit the fertilizing ability before the nucleus is affected. Therefore achieving non-obstructive vas-based contraception, without genotoxic or teratogenic effects caused by infertile sperm passing into the semen, is feasible.展开更多
文摘Spermiogenesis is a dynamic process which includes organelle reorganization and new structure formation. The morphology and distribution of the mitochondria in germ cells change to accommodate the cellular requirement. Multiple molecular motors and related proteins participate in carrying and anchoring mitochondria to the midpiece during spermiogenesis and this process is regulated precisely. Energetic metabolism provides energy for cellular activity and influences sperm survival and motility directly. Ubiquitination of mitochondria takes place during spermiogenesis, which has been implicated in sperm quality control and mitochondrial inheritance. In light of the essential roles of mitochondria in energy production, calcium homeostasis and apoptosis, mitochondria dysfunction cause severe human diseases, such as male infertility. The present study paves a way for a more detailed exploration of the biology of mitochondria during spermiogenesis.
基金Acknowledgment This work was supported by grants from the National Natural Science Foundation of China （No. 30470703）. The authors would like to thank Dr Jian- Feng Li for his valuable comments and assistance.
文摘Aim： To investigate whether early apoptotic changes in spermatozoa can be significant markers for sperm quality. Methods： Two early apoptotic changes in the semen of 56 men were assessed using Annexin V （AN）/propidium iodide （PI） staining for phosphatidylserine externalization and JC-1 staining for mitochondrial membrane potential （MMP）. The results were compared with conventional semen parameters and DNA fragmentation identified using the TUNEL assay. Results： The different labeling patterns in the bivariate Annexin V/PI analysis identified four distinctive spermatozoa populations. The percentage of AN^-/PI^- spermatozoa positively correlated with conventional semen parameters and MMP, but negatively correlated with TUNEL （＋） spermatozoa. As for the AN^-/PI^＋ fraction, we found an opposite result in comparison to AN^-/PI^- spermatozoa. The level of early apoptotic AN^＋/PI^- spermatozoa negatively correlated with MMP and sperm motility. The level of late apoptotic AN^＋/PI^＋ spermatozoa negatively correlated with conventional semen parameters and MMP, and positively correlated with TUNEL （＋） spermatozoa. MMP positively correlated with conventional semen parameters, but negatively correlated with TUNEL （＋） spermatozoa. Conclusion： Although early apoptotic AN^＋/PI^- spermatozoa only negatively correlates with sperm motility, the differences in proportion of each subpopulation of spermatozoa （especially, the percentage of AN^-/PI^- spermatozoa）, and decreased MMP might be significant markers for diagnosing male infertility. They possibly bring additional information to predict the outcome of in vitro fertilization. （Asian J Androl 2008 Mar; 10： 227-235）
文摘Aim： To determine the short and long-term morphological effects on sperm as induced by intra-vas alteration of pH and electrical charge. Methods： Desired biophysical influences were obtained by injection of reversible inhibition of sperm under guidance （RISUG） into the lumen of the vas deferens of human subjects and the monkey. RISUG is a polyelectrolyte hydrogel complex of styrene maleic anhydride （SMA） and dimethyl sulfoxide （DMSO） which generates an electrostatic charge and also lowers in a near space of pH domain. The morphology of sperm was examined by light microscopy, scanning and transmission electron microscopy. Human study enabled semen collection by masturbation as early as 3 h after injection and studies extended up to 6 months, in the monkey, on vas excision after RISUG implantation, sperm characteristics were examined in serial sections. Results： Semenology in clinical studies and histological data of the monkey showed a time-sequenced sperm plasma membrane, tail mitochondria and nuclear decondensation alterations in sperm structural components, which beared marked similarity to changes in the sperm head and tail during capacitation and entry into the ovum. Conclusion： The findings provide a means of causing such changes in the sperm that inhibit the fertilizing ability before the nucleus is affected. Therefore achieving non-obstructive vas-based contraception, without genotoxic or teratogenic effects caused by infertile sperm passing into the semen, is feasible.
