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Germ Cell Apoptosis (germ + cell_apoptosi)
Selected AbstractsGerm cell apoptosis induced by experimental cryptorchidism is mediated by molecular pathways in mouse testisANDROLOGIA, Issue 1 2010F. Absalan Summary The aim of the study was to characterise the alterations in expression of some apoptosis regulators in unilaterally and bilaterally heat-treated mouse testes at different time intervals to 42 days after surgery. Cryptorchidism was induced in immature mice by returning the testis to the abdominal cavity via a surgical procedure. Transcript levels of Bax, Bcl-2 proper, p53 and survivin mRNA and protein were determined in normal and cryptorchid testes using reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry. RT-PCR data verified the elevation of p53 expression and decrease of Bax and Bcl-2 proper mRNA in the cryptorchid testis in a time-dependent manner. The expression of survivin 140 and 40 variants strongly decreased in the bilateral groups compared with unilateral and control groups. These changes were significantly different in the bilateral groups in comparison with the unilateral groups. Immunohistochemistry data showed that the intensity of p53 and Bax expression mainly increased in the remainder cells in the cryptorchid testis and the rates of Bcl-2 proper and survivin expression decreased mainly in the bilateral groups. These observations suggest that multiple molecular pathways participate in the germ cell apoptosis induced by cryptorchidism. [source] Paternal transmission of genetic damage: findings in animals and humansINTERNATIONAL JOURNAL OF ANDROLOGY, Issue 3 2000Martin H. Brinkworth The concept that mutations can be induced in the male germ-line and result in adverse effects in the offspring has achieved only limited acceptance despite considerable theoretical appeal. This is partly because fetal malformations are generally perceived to be induced solely as a result of maternally mediated events during gestation and partly because the low incidence of the end-points concerned make experimental approaches costly and time-consuming. Nonetheless, a substantial body of work relating to the hypothesis has accumulated in the last 20 years, which has never been reviewed in its entirety. A consideration of the available evidence indicates that preconceptional paternal exposure to mutagens (particularly radiation, cyclophosphamide and ethylnitrosourea) can indeed, under certain conditions, have adverse effects on offspring. The results suggest two principal mechanisms by which such effects may be induced: the induction of germ-line genomic instability or the suppression of germ cell apoptosis. [source] Influence for testicular development and histological peculiarity in the testes of flutamide-induced cryptorchid rat modelINTERNATIONAL JOURNAL OF UROLOGY, Issue 1 2007Kentaro Mizuno Objectives: To investigate influence for the testicular development and to assess the usefulness as an animal model, cryptorchid rats were induced by exposure to flutamide during the fetal period and their testes examined histologically. Methods: Flutamide was injected into the abdomen of pregnant rats for 7 days from the 14th to 20th day of gestation. The male offspring in which cryptorchidism was observed at 28 days after birth were defined as the model rats. They were divided into four groups by dosage of flutamide (2.5 mg, 5 mg, 7.5 mg, 15 mg per day), and their testicular weight, spermatogenesis (modified Johnsen score), and germ cell apoptosis were examined histochemically at 10 weeks after birth. Results: The incidence of cryptorchidism including both unilateral and bilateral in the 2.5, 5, 7.5 and 15-mg flutamide groups was 58.3%, 81.9%, 93.6% and 91.0%, respectively. In the model rats, the undescended testes were located at the caudal end of the abdominal cavity, and these testes weighed less than the contra-descended testes in each group. Histologically, apoptotic cells were markedly increased, the seminiferous tubules were degenerated and disturbance of spermatid differentiation was observed in the undescended testes compared with the normal or contra-lateral descended testes. Conclusions: We found out that the incidence of undescended testes increased in a flutamide dose-dependent manner. The findings of histological examination were independent of the administrated dose of flutamide and it is suggested that exposure of the testes to abdominal temperature causes spermatogenic arrest with germ cell apoptosis. The present animal model indicates high incidence of above 90%, has no surgical stress and dose not require special techniques. We believe that the present model is a useful tool for the understanding of pathogenesis and treatment of cryptorchidism and further biological research into spermatogenesis. [source] Bis(4,7-dimethyl and 5-dinitro-1,10-phenanthroline) sulfato-oxovanadium(IV)-mediated in vivo male germ cell apoptosisJOURNAL OF APPLIED TOXICOLOGY, Issue 4 2001Osmond J. D'Cruz Abstract Oxovanadium(IV) [VO] complexes of 1,10-phenanthroline are a new class of potent apoptosis-inducing cytotoxic agents against human testicular cancer cells in vitro. The present study investigated the in vivo ability of four(bis)-chelated 1,10-phenanthroline [phen] complexes of sulfato-oxovanadium(IV),VO(phen)2, VO(Cl,phen)2, VO(Me2,phen)2 and VO(NO2,phen)2,with and without substitutions, to induce testicular germ cell apoptosis. Male germ cell loss in mice was measured by determining the epididymal sperm count, testicular weight and histological evaluation of the testes. Repetitive intratesticular injection (7.5 mg kg,1 testis,1) of bis-chelated 1,10-phenanthroline complexes of oxovanadium(IV) with 4,7-dimethyl [VO(Me2,phen)2] and 5-dinitro [VO(NO2,phen)2] substitution led to decreased sperm counts and reduced testicular weights. Histopathological examination of testicular sections from VO(Me2,phen)2 - and VO(NO2,phen)2 -treated mice revealed a marked inhibition of spermatogenesis and preferential loss of maturing, as well as elongated spermatids. In situ evaluation of seminiferous tubule cross-sections by terminal deoxynucleotidyl transferase-mediated FITC-deoxyuridine triphosphate nick end-labeling (TUNEL) and laser scanning confocal microscopy showed characteristic apoptotic germ cells delineating the periphery of the seminiferous tubules. The ability of bis-chelated 4,7-dimethyl- and 5-dinitro-substituted 1,10-phenanthroline complexes of oxovanadium(IV) to induce germ cell apoptosis in vivo may have potential utility in the treatment of human testicular germ cell tumors. Copyright © 2001 John Wiley & Sons, Ltd. [source] Ethanol Exposure Enhances Apoptosis Within the TestesALCOHOLISM, Issue 10 2000Qianlong Zhu Background: Chronic ethanol abuse causes testicular atrophy and male infertility in alcoholic men. It is well known that ethanol exposure disrupts the hypothalamic-pituitary-gonadal axis, adversely affects the secretory function of Sertoli cells, and produces oxidative stress within the testes. It is still not clear what cellular mechanisms are responsible for the morphologic alteration of the testes that results in a reduction of testicular mass as a consequence of ethanol exposure. The hypothesis tested was that ethanol enhances apoptosis of testicular germ cells. Methods: In the experiments of chronic ethanol exposure, male Sprague Dawley® rats (Harlan Sprague Dawley, Inc., Indianapolis, IN) were fed Liber-Decarlie liquid diet for 9 weeks. In the experiments of acute ethanol exposure, a small volume of 20% ethanol solution was administered by intratesticular injection. Both 3,-end labeling of isolated testicular deoxyribonucleic acid (DNA) and labeling of apoptotic cells in situ by the terminal deoxynucleotidyl transferase-mediated deoxyuridine 5,-triphosphate nick end-labeling method were used to determine apoptosis rates within the testes. The expression of proteins involved in apoptosis was assessed by reverse transcription-polymerase chain reaction and by Western blotting. Results: The testes of rats that were fed an ethanol-containing liquid diet had more testicular DNA fragmentation than did those of animals that were fed an isocaloric control diet. Ethanol increased the number of apoptotic spermatogonia as well as spermatocytes. Direct intratesticular injections of ethanol solution enhanced testicular DNA fragmentation, suggesting an increase in apoptosis. Moreover, Fas ligand levels were increased within the testes of rats that were chronically fed ethanol. In vitro, ethanol treatment of cultured Sertoli cells enhanced the production of Fas ligand. In addition, testicular levels of p53 messenger ribonucleic acid were increased in rats that were chronically fed ethanol. Conclusions: All of these observations suggest that ethanol enhances testicular germ cell apoptosis. [source] Use of combined in silico expression data and phylogenetic analysis to identify new oocyte genes encoding RNA binding proteins in the mouseMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 12 2008Laurence Drouilhet Abstract During folliculogenesis, oocytes accumulate maternal mRNAs in preparation for the first steps of early embryogenesis. The processing of oocyte mRNAs is ensured by heterogeneous nuclear ribonucleoproteins (hnRNPs) genes that encode RNA binding proteins implied in mRNA biogenesis, translation, alternative splicing, nuclear exportation, and degradation. In the present work, by combining phylogenetic analyses and, when available, in silico expression data, we have identified three new oocyte-expressed genes encoding RNA binding proteins by using two strategies. Firstly, we have identified mouse orthologs of the Car1 gene, known to be involved in regulation of germ cell apoptosis in C. elegans, and of the Squid gene, required for the establishment of anteroposterior polarity in the Drosophila oocyte. Secondly, we have identified, among genes whose ESTs are highly represented in oocyte libraries, a paralog of Poly(A) binding protein,Interacting Protein 2 (Paip2) gene, known to inhibit the interaction of the Poly(A)-Binding Protein with Poly(A) tails of mRNAs. For all of these genes, the expression in oocyte was verified by in situ hybridization. Overall, this work underlines the efficiency of in silico methodologies to identify new genes involved in biological processes such as oogenesis. Mol. Reprod. Dev. 75: 1691,1700, 2008. © 2008 Wiley-Liss, Inc. [source] Relevance of caspase activity during apoptosis in pubertal rat spermatogenesisMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 5 2008Veronica A. Codelia Abstract Caspases are a family of cysteine-proteases, activated upon several different stimuli, which execute apoptosis in many cell death models. Previous work of our group has shown rats have the highest rate of apoptosis during the first wave of spermatogenesis (between 20 and 25 days after birth), as evaluated by TUNEL and caspase activity. However, the hierarchical order of caspase activation and the relevance of each caspase during germ cell apoptosis are not clear. Thus, the goal of this work is to take a pharmacological approach to dissect the apoptosis pathway of caspase activation. Results showed that intratesticular injection of a caspase-8 inhibitor (z-IETD-fmk), or a pan-caspase inhibitor (z-VAD- fmk), significantly decreased the cleavage of p115 and PARP, two endogenous substrates of caspases, in 22-day-old rats. Additionally, these inhibitors promoted a significant reduction in the number of apoptotic germ cells. On the other hand, intratesticular injection of two different inhibitors of the intrinsic pathway (z-LEHD-fmk and minocycline) did not have any effect upon caspase substrates cleavage (p115 and PARP) or the number of apoptotic germ cells. Therefore, we conclude that the extrinsic pathway of apoptosis plays an important role in physiological germ cell apoptosis during the first round of spermatogenesis in the rat. Mol. Reprod. Dev. 75: 881,889, 2008. © 2007 Wiley-Liss, Inc. [source] Mice lacking cyclin-dependent kinase inhibitor p19Ink4d show strain-specific effects on male reproductionMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 8 2007Gregory M. Buchold Abstract p19Ink4d is a member of the INK4 family of cyclin-dependent kinase inhibitors, which are important negative regulators of the G1-phase cyclin-dependent kinases CDK4 and CDK6. On a mixed C57BL/6,×,129P2/OlaHsd background, mice deficient for p19Ink4d exhibited defects in male reproductive function including testicular atrophy, alteration in serum follicle stimulating hormone, qualitative increase in germ cell apoptosis, and delayed kinetics of meiotic prophase markers (Zindy et al., 2001. Mol Cell Biol 21:3244,3255; Zindy et al., 2000. Mol Cell Biol 20:372,378). In this study, a quantitative assessment of these aspects of reproductive capacity demonstrated relatively mild deficits in p19Ink4d,/, males compared to controls. These effects did not dramatically worsen in older males although some seminiferous tubule defects were observed. Following marker-assisted backcrossing into the C57BL/6 background, p19Ink4d,/, males did not display defects in testis weights, sperm numbers, serum FSH, germ cell apoptosis, or kinetics of selected meiotic prophase markers. These studies indicate that a reduction in Ink4 family function by the loss of p19Ink4d is sufficient to induce mild reproductive defects in male mice with a mixed genetic background, but not in the C57BL/6 genetic background. Mol. Reprod. Dev. 74: 1008,1020, 2007. © 2007 Wiley-Liss, Inc. [source] Germ cell apoptosis induced by experimental cryptorchidism is mediated by molecular pathways in mouse testisANDROLOGIA, Issue 1 2010F. Absalan Summary The aim of the study was to characterise the alterations in expression of some apoptosis regulators in unilaterally and bilaterally heat-treated mouse testes at different time intervals to 42 days after surgery. Cryptorchidism was induced in immature mice by returning the testis to the abdominal cavity via a surgical procedure. Transcript levels of Bax, Bcl-2 proper, p53 and survivin mRNA and protein were determined in normal and cryptorchid testes using reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry. RT-PCR data verified the elevation of p53 expression and decrease of Bax and Bcl-2 proper mRNA in the cryptorchid testis in a time-dependent manner. The expression of survivin 140 and 40 variants strongly decreased in the bilateral groups compared with unilateral and control groups. These changes were significantly different in the bilateral groups in comparison with the unilateral groups. Immunohistochemistry data showed that the intensity of p53 and Bax expression mainly increased in the remainder cells in the cryptorchid testis and the rates of Bcl-2 proper and survivin expression decreased mainly in the bilateral groups. These observations suggest that multiple molecular pathways participate in the germ cell apoptosis induced by cryptorchidism. [source] The Fas system in the seminiferous epithelium and its possible extra-testicular roleANDROLOGIA, Issue 1 2003A. Riccioli Summary. The Fas system is involved in the control of immune system homeostasis and nonfunctional Fas system leads to autoimmune disease in mice and humans. The Fas system is a mechanism through which cells expressing Fas ligand (FasL) induce apoptosis of Fas expressing cells. In mouse and rat, the testis represents the main source of constitutive FasL in the body. The roles so far proposed for this molecule in the testis, such as maintenance of immunoprivilege and regulation of physiological germ cell apoptosis, need to be reconsidered as both hypotheses are based on an erroneous cellular location of FasL in the seminiferous epithelium. Recently, we demonstrated that in rodents FasL mRNA is present in germ cells and not in Sertoli cells, and that FasL protein is displayed on the surface of spermatozoa. Here we propose that, for the mouse spermatozoa, the FasL may represent a self-defence mechanism against lymphocytes present in the female genital tract. To verify this hypothesis, we performed crossings between males gld, with nonfunctional FasL, and syngenic or nonsyngenic females. We observed a significant decrease of litter size in outbred crossings with gld males compared with wild-type males, suggesting a possible role of FasL in immunoprotection of the sperm in the female genital tract. The possibility that in humans, by analogy with mouse, FasL plays a self-protective role for the spermatozoon cannot be excluded, and awaits experimental information on the expression of FasL on human sperm cells. [source] Effects of 60 Hz 14 µT magnetic field on the apoptosis of testicular germ cell in miceBIOELECTROMAGNETICS, Issue 1 2009Yoon-Won Kim Abstract We recently reported that continuous exposure, for 8 weeks, of extremely low frequency (ELF) magnetic field (MF) of 0.1 or 0.5 mT might induce testicular germ cell apoptosis in BALB/c mice. In that report, the ELF MF exposure did not significantly affect the body weight or testicular weight, but significantly increased the incidence of testicular germ cell death. In the present study, we aimed to further characterize the effect of a 16-week continuous exposure to ELF MF of 14 or 200 µT on testicular germ cell apoptosis in mice. There were no significant effects of MF on body weight and testosterone levels in mice. In TUNEL staining (In situ terminal deoxynucleotidyl transferase-mediated deoxy-UTP nick end labeling), germ cells showed a significantly higher apoptotic rate in exposed mice than in sham controls (P,<,0.001). TUNEL-positive cells were mainly spermatogonia. In an electron microscopic study, degenerating spermatogonia showed condensation of nuclear chromatin similar to apoptosis. These results indicate that apoptosis may be induced in spermatogenic cells in mice by continuous exposure to 60 Hz MF of 14 µT. Bioelectromagnetics 30:66,72, 2009. © 2008 Wiley-Liss, Inc. [source] Effect of insulin-like growth factor-1 on apoptosis of rat testicular germ cells induced by testicular torsionBJU INTERNATIONAL, Issue 7 2004C. Ozkurkcugil OBJECTIVE To investigate the possible protective role of insulin-like growth factor-1 (IGF-1, reported to have a protective effect in experimental models of hypoxic ischaemia), and the involvement of apoptotic cell death in a model of torsion/detorsion of the rat testis. MATERIALS AND METHODS Adult male Wistar rats were divided into five groups of five rats each. Group 1 underwent a sham operation as a control; in group 2 the testis was twisted and in group 3 then untwisted; in group 4 IGF-1 was injected subcutaneously just before bilateral torsion, and then the right testis removed after 4 h and the left after 24 h; in group 5, IGF-1 was injected immediately after bilateral detorsion and then the testes removed as in group 4. Both testicles were examined histologically, with apoptosis detected using the in situ DNA fragmentation (TUNEL) system, with combined enzymology and immunohistochemistry techniques. RESULTS In groups 2 (torsion) and 3 (detorsion), light microscopy of the testis showed some degenerative changes in the germ cells. Compared to group 1, apoptosis was more significant in group 3 than in the other groups. Group 4 (torsion/IGF-1) had a similar number of apoptotic germ cells as in group 2 (torsion) after 24 h, but fewer than the same group after 4 h. In group 5 (detorsion/IGF-1), apoptosis was reduced by IGF-1 significantly more than in group 3 (P < 0.05). Apoptosis was significantly less in spermatids in group 5 than in group 3 (P < 0.05). CONCLUSIONS IGF-1 seems to lower the levels of germ cell apoptosis, which may be important for protecting the testes from torsion/detorsion injury. Further clinical studies are needed to evaluate this protective effect in testicular torsion/detorsion. [source] | |||||||||||||||||||||||||