Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.22.56 (caspase-3)
 35,750 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Differentiating male germ cells express a testis-specific form of cytochrome c (Cyt c(T)) that is distinct from the cytochrome c expressed in somatic cells (Cyt c(S)). To examine the role of Cyt c(T) in germ cells, we generated mice null for Cyt c(T). Homozygous Cyt c(T)(-/-) pups were statistically underrepresented (21%) but developed normally and were fertile. However, spermatozoa isolated from the cauda epididymis of Cyt c(T)-null animals were less effective in fertilizing oocytes in vitro and contain reduced levels of ATP compared to wild-type sperm. Sperm from Cyt c(T)-null mice contained a greater number of immotile spermatozoa than did samples from control mice, i.e., 53.1% +/- 13.7% versus 33.2% +/- 10.3% (P < 0.0001) for vas deferens sperm and 40.1% +/- 9.6% versus 33.2% +/- 7.5% (P = 0.0104) for epididymal sperm. Cyt c(T)-null mice often exhibit early atrophy of the testes after 4 months of age, losing germ cells as a result of increased apoptosis. However, no difference in the activation of caspase-3, -8, or -9 was detected between the Cyt c(T)(-/-) testes and controls. Our data indicate that the Cyt c(T)-null testes undergo early atrophy equivalent to that which occurs during aging as a consequence of a reduction in oxidative phosphorylation.
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PMID:Testis-specific cytochrome c-null mice produce functional sperm but undergo early testicular atrophy. 1210 Dec 47

Cryopreservation causes a significant proportion of bovine oocytes to undergo degeneration during subsequent culture. We investigated the degeneration mechanism of cryopreserved oocytes. In vitro matured bovine oocytes were vitrified by the open-pulled straw (OPS) method. In each replicate, a group of oocytes were randomly taken after warming to determine oocyte survival by both morphological evaluation and propidium iodide vital staining. The remainders were evaluated by morphological criterion. Morphologically intact oocytes were co-incubated with frozen-thawed spermatozoa for subsequent development. In situ examination of DNA breaks in oocytes and embryos was conducted using a Fluorescein-FragEL DNA fragmentation detection kit. A caspase-3 detection kit was used to detect caspase-3 activity in oocytes and embryos. Most of the oocytes survived cooling and warming processes as assessed by both morphological evaluation and vital stain. During subsequent culture, some degenerating oocytes displayed observable apoptotic morphology, such as cytoplasmic condensation, cytoplasmic fragmentation, and formation of apoptotic bodies. Biochemical markers of apoptosis, such as apoptotic DNA fragmentation and activation of caspases, were detected not only in oocytes having typical apoptotic morphology, but also in oocytes without observable apoptotic morphology. In embryos, positive signals for both biochemical markers were detected in blastomeres. This experiment suggests that cryopreserved bovine oocytes degenerate via apoptosis during subsequent culture.
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PMID:Degeneration of cryopreserved bovine oocytes via apoptosis during subsequent culture. 1296 14

Ejaculated spermatozoa, particularly in infertile men, have been shown to display morphological and biochemical features that are typical of an apoptotic phenotype in somatic cells. Deregulation of apoptosis is known to play roles in a number of disease processes, but roles for apoptosis in ejaculated spermatozoa and male infertility are poorly defined or have not been studied. Preliminary data demonstrated that populations of ejaculated spermatozoa express: (i) various degrees of plasma membrane translocation of phosphatidylserine and DNA fragmentation; and (ii) active caspase-3, the main executor of apoptosis in somatic cells, with an apparent exclusive cellular location to the mid-piece. Tests are currently being carried out on the effects of well-known apoptosis agonists and caspase inhibitors on such markers using purified populations of leukocyte-free ejaculated human spermatozoa. The main objective is to determine if somatic cell apoptosis markers are relevant indicators and/or causative factors of male infertility.
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PMID:Presence and significance of somatic cell apoptosis markers in human ejaculated spermatozoa. 1465 10

Ubiquitination is required throughout all developmental stages of mammalian spermatogenesis. Ubiquitin C-terminal hydrolase (UCH) L1 is thought to associate with monoubiquitin to control ubiquitin levels. Previously, we found that UCHL1-deficient testes of gad mice have reduced ubiquitin levels and are resistant to cryptorchid stress-related injury. Here, we analyzed the function of UCHL1 during the first round of spermatogenesis and during sperm maturation, both of which are known to require ubiquitin-mediated proteolysis. Testicular germ cells in the immature testes of gad mice were resistant to the early apoptotic wave that occurs during the first round of spermatogenesis. TUNEL staining and cell quantitation demonstrated decreased germ cell apoptosis and increased numbers of premeiotic germ cells in gad mice between Postnatal Days 7 and 14. Expression of the apoptotic proteins TRP53, Bax, and caspase-3 was also significantly lower in the immature testes of gad mice. In adult gad mice, cauda epididymidis weight, sperm number in the epididymis, and sperm motility were reduced. Moreover, the number of defective spermatozoa was significantly increased; however, complete infertility was not detected. These data indicate that UCHL1 is required for normal spermatogenesis and sperm quality control and demonstrate the importance of UCHL1-dependent apoptosis in spermatogonial cell and sperm maturation.
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PMID:Ubiquitin C-terminal hydrolase L-1 is essential for the early apoptotic wave of germinal cells and for sperm quality control during spermatogenesis. 1574 22

The selection of vital, non-apoptotic spermatozoa is a prerequisite for achieving optimal conception rates in assisted reproductive techniques. Magnetic cell sorting using annexin-V microbeads can effectively separate apoptotic and non-apoptotic spermatozoa. The objective of the present study was to optimize the integration of magnetic cell sorting in standard sperm preparations and to correlate the effect of different sperm preparation procedures on apoptotic markers. Semen specimens collected from 15 healthy donors were prepared by either density gradient centrifugation or by one-step sperm wash technique separately and in combination with magnetic cell sorting. The preparation methods were evaluated by assessment of semen parameters (motility, viability and morphology) as well as markers of apoptosis (levels of active caspase-3, integrity of membrane mitochondrial potential and externalization of phosphatidylserine). The apoptotic markers were measured using fluorochrome dyes coupled with flow cytometry. The results showed that the combination of density gradient centrifugation and annexin-V magnetic cell sorting was superior to all other sperm preparation methods in terms of providing motile, viable and non-apoptotic spermatozoa. This study clearly shows the advantage of integrating magnetic cell sorting as a part of sperm preparation, which in turn may positively affect the success rates of assisted reproductive techniques.
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PMID:Advantage of combining magnetic cell separation with sperm preparation techniques. 1597 4

Cellular stress to ejaculated spermatozoa such as cryopreservation is known to induce caspase-derived, apoptotic signaling. Therefore, the proenzymes and active forms of caspases 1, 3, 8 and 9 were examined by western blot technique in unfrozen and frozen human spermatozoa of infertility patients and of healthy donors. Twenty-two semen samples derived from healthy donors and 26 semen samples of unselected infertility patients were divided into 3 parts, two of them were cryostored at -196 degrees C with 7% or 14% (v/v, final concentration) of glycerol. The caspases were detected by immunoblots with polyclonal rabbit-anti-caspases-antibodies after 15% sodium dodecyl sulfate-polyacrylgel electrophoresis (SDS-PAGE) under reducing conditions. For evaluation of the differences between amounts of caspase protein the luminol/H(2)O(2) method was applied. A significant increase of activated caspase-1 in donors, of caspase-8 in patients and caspase-9 in patients and donors after cryopreservation were found, whereas, the application of 14% glycerol resulted in higher amounts of activated caspase than did 7% glycerol. Possibly, glycerol may also contribute to activation of caspases via direct toxic effects to mitochondria during cryopreservation of spermatozoa. This finding strongly supports an hypothesis of a higher mitochondria-derived apoptosis-sensitivity of spermatozoa in patients than in healthy donors during cryopreservation. Inactive caspase-3 was reduced subsequent to cryopreservation in patients (p<0.05) and non-significant in donors (p<0.05). Active caspase-3 was detectable in all samples but without significant differences between the three assays. It is concluded that mechanisms associated with apoptotic processes deserve attention in cryopreservation of spermatozoa in order to conserve vital sperm functions after thawing.
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PMID:Activation of caspases in human spermatozoa during cryopreservation--an immunoblot study. 1673 10

The accurate measurement of semen fertilizing potential is of great importance in determining the acceptability of processed semen for breeding purposes. A good sperm preparation technique results in a sample with high viability and motility and also takes into account other parameters such as the capacitation and apoptotic state which could compromise the ability to fertilize an oocyte. In this study, we investigate the effects of 4 sperm preparation techniques (a dextran/swim-up procedure, discontinuous Percoll density gradient centrifugation, sucrose washing, and filtration) on ram sperm quality parameters. Besides the evaluation of viability and the capacitation state, we also analyzed the apoptotic status of the sperm samples by assessing the phosphatidylserine translocation and caspase-3 and -7 activities. This is the first report, to our knowledge, that evidences the presence of active caspases in ram sperm. The results confirm the better ability of the dextran/swim-up procedure to select nonapoptotic spermatozoa, in addition to viable and noncapacitated sperm, compared with other sperm preparation methods. This should be considered to enhance results of artificial insemination techniques in ovine reproduction.
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PMID:Comparative study of four different sperm washing methods using apoptotic markers in ram spermatozoa. 1680 77

Toxicity of the polychlorinated biphenyls (PCBs) depends on their molecular structure. Mechanisms by prenatal exposure to a non-dioxin-like PCB, 2,2',3,4',5',6-hexachlorobiphenyl (PCB 132) that may act on reproductive pathways in male offspring are relatively unknown. The purpose was to determine whether epididymal sperm function and expression of apoptosis-related genes were induced or inhibited by prenatal exposure to PCB 132. Pregnant rats were treated with a single dose of PCB 132 at 1 or 10 mg/kg on gestational day 15. Male offspring were killed and the epididymal sperm counts, motility, velocity, reactive oxygen species (ROS) generation, sperm-oocyte penetration rate (SOPR), testicular histopathology, apoptosis-related gene expression and caspase activation were assessed on postnatal day 84. Prenatal exposure to PCB 132 with a single dose of 1 or 10 mg/kg decreased cauda epididymal weight, epididymal sperm count and motile epididymal sperm count in adult offspring. The spermatozoa of PCB 132-exposed offspring produced significantly higher levels of ROS than the controls; ROS induction and SOPR reduction were dose-related. In the low-dose PCB 132 group, p53 was significantly induced and caspase-3 was inhibited. In the high-dose group, activation of caspase-3 and -9 was significantly increased, while the expressions of Fas, Bax, bcl-2, and p53 genes were significantly decreased. Gene expression and caspase activation data may provide insight into the mechanisms by which exposure to low-dose or high-dose PCB 132 affects reproduction in male offspring in rats. Because the doses of PCB 132 administered to the dams were approximately 625-fold in low-dose group and 6250-fold higher in high-dose group than the concentration in human tissue levels, the concentrations are not biologically or environmentally relevant. Further studies using environmentally relevant doses are needed for hazard identification.
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PMID:Exposure in utero to 2,2',3,3',4,6'-hexachlorobiphenyl (PCB 132) impairs sperm function and alters testicular apoptosis-related gene expression in rat offspring. 1744 52

Human sperm have been documented to display apoptosis-like features such as externalization of phosphatidylserine (EPS), disruption of the transmembrane mitochondrial potential (MMP) and activation of caspases. Our aim was to evaluate possible association between activation of the apoptosis cascade in human sperm and its oocyte penetration capacity using the zona free hamster oocyte penetration assay (SPA). Semen specimens from 76 unselected donors were subjected to double density gradient centrifugation followed by incubation under capacitating conditions for 3 h and SPA. Apoptosis signalling was monitored by assessment of EPS, disruption of MMP and activation of caspase-3 by flow cytometry. Semen samples with subnormal SPA values (<20% penetrated oocytes) contained significantly higher amounts of spermatozoa with EPS, disrupted MMP and activated caspase-3 compared with those samples with normal SPA values (>20% penetrated oocytes, p < 0.01). All three apoptosis markers showed a significantly negative correlation with the percentage of penetrated oocytes (p < 0.01). Apoptosis-related signalling appears to have a negative association with sperm-oocyte penetration. The exclusion of sperm presenting with those apoptosis-related features during assisted reproduction may improve success rates of procedures such as intrauterine insemination and in vitro fertilization.
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PMID:Relationship between sperm apoptosis signalling and oocyte penetration capacity. 1757 51

To identify the mechanisms underlying capacitation, we undertook a high-resolution differential proteomic analysis of pig sperm cells. Two-dimensional gel electrophoresis and subsequent MALDI-TOF mass spectrometry analyses led to identification of 56 differentially expressed proteins. After induction of capacitation in vitro, the well-established markers of the capacitation (lactadherin P47, acrosomal protein SP-10 precursor, prohibitin, proteasomes, DJ-1 protein and arylsulfatase-A) and TCA cycle proteins (isocitrate dehydrogenase, malate dehydrogenase and pyruvate dehydrogenase) were identified. During induction, cytochrome c expression via the p53 pathway increased, however apoptotic executors, such as caspase-3, decreased significantly. Therefore, we tested the hypothesis that cytochrome c upregulation in spermatozoa is capable of activating tyrosine phosphorylation for capacitation, rather than apoptosis. Exposure of sperm cells to soluble Na2CrO4 [Cr (VI)], which induces cytochrome c upregulation, caused a dose- and time-dependent increase in tyrosine phosphorylation of sperm proteins in non-capacitating medium. In contrast, supplementation of cyclosporin A, which blocks cytochrome c upregulation, inhibited tyrosine phosphorylation of sperm proteins. Furthermore, spermatozoa in capacitation medium or non-capacitation media supplemented with soluble Cr (VI) showed similar levels of capacitation. These findings indicate that differential expression of many of these proteins has previously been unrecognized in sperm cells incubated in capacitation medium also suggest that a gradual increase of cytochrome c during incubation to induce capacitation determines sperm cell fate, i.e., apoptosis or further development for fertilization.
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PMID:Cytochrome c upregulation during capacitation and spontaneous acrosome reaction determines the fate of pig sperm cells: linking proteome analysis. 1809 29


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