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Kirimlioglu E, Oflamaz AO, Hidisoglu E, Ozen S, Yargicoglu P, Demir N. Short and long-term 2100 MHz radiofrequency radiation causes endoplasmic reticulum stress in rat testis. Histochem Cell Biol 2024; 162:311-321. [PMID: 38997526 PMCID: PMC11364557 DOI: 10.1007/s00418-024-02308-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/28/2024] [Indexed: 07/14/2024]
Abstract
Long-term radiofrequency radiation (RFR) exposure, which adversely affects organisms, deteriorates testicular functions. Misfolding or unfolding protein accumulation in the endoplasmic reticulum (ER) initiates an intracellular reaction known as ER stress (ERS), which activates the unfolded protein response (UPR) for proteostasis. Since both RFR exposure and ERS can cause male infertility, we hypothesized that RFR exposure causes ERS to adversely affect testicular functions in rats. To investigate role of ERS in mediating RFR effects on rat testis, we established five experimental groups in male rats: control, short-term 2100-megahertz (MHz) RFR (1-week), short-term sham (sham/1-week), long-term 2100-MHz RFR (10-week), and long-term sham (sham/10-week). ERS markers Grp78 and phosphorylated PERK (p-Perk) levels and ERS-related apoptosis markers Chop and caspase 12 were investigated by immunohistochemistry, immunoblotting, and quantitative real-time polymerase chain reaction (qPCR). Long-term RFR exposure increased Grp78, p-Perk, and Chop levels, while short-term RFR exposure elevated Chop and caspase 12 levels. Chop expression was not observed in spermatogonia and primary spermatocytes, which may protect spermatogonia and primary spermatocytes against RFR-induced ERS-mediated apoptosis, thereby allowing transmission of genetic material to next generations. While short and long-term RFR exposures trigger ERS and ERS-related apoptotic pathways, further functional analyses are needed to elucidate whether this RFR-induced apoptosis has long-term male infertility effects.
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Affiliation(s)
- Esma Kirimlioglu
- Departments of Histology and Embryology, Faculty of Engineering, Akdeniz University, Antalya, Turkey.
| | - Asli Okan Oflamaz
- Departments of Histology and Embryology, Faculty of Engineering, Akdeniz University, Antalya, Turkey
- Faculty of Medicine, Department of Histology and Embryology, Bozok University, Yozgat, Turkey
| | - Enis Hidisoglu
- Departments of Biophysics, Faculty of Medicine, Faculty of Engineering, Akdeniz University, Antalya, Turkey
- Department of Drug Science, NIS Centre, University of Turin, Turin, Italy
| | - Sukru Ozen
- Department of Electrical and Electronics Engineering, Faculty of Engineering, Akdeniz University, Antalya, Turkey
| | - Piraye Yargicoglu
- Departments of Biophysics, Faculty of Medicine, Faculty of Engineering, Akdeniz University, Antalya, Turkey
| | - Necdet Demir
- Departments of Histology and Embryology, Faculty of Engineering, Akdeniz University, Antalya, Turkey
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2
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Lin M, Guo L, Cheng Z, Huan X, Huang Y, Xu K. Association of hMSH5 C85T polymorphism with radiation sensitivity of testicular cell lines GC-1, GC-2, TM3, and TM4. Andrology 2020; 8:1174-1183. [PMID: 32306546 DOI: 10.1111/andr.12803] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 03/12/2020] [Accepted: 04/14/2020] [Indexed: 12/01/2022]
Abstract
BACKGROUND The hMSH5 C85T polymorphism, which encodes hMSH5 P29S, is associated with individual differences in spermatogenic abnormalities caused by ionizing radiation (IR), but the molecular mechanisms remain unclear. OBJECTIVES This manuscript aims to explore the role of hMSH5 C85T polymorphism in IR-induced individual differences in spermatogenic abnormalities. MATERIAL AND METHODS We transfected pcDNA-hMSH5P29S vector into mouse spermatogonia GC-1, mouse spermatocytes GC-2, mouse testicular mesenchymal cells TM3, and mouse testicular support cells TM4. After radiation, we evaluated cell survival with colony formation assay, apoptosis with TUNEL assay and caspase-3 activity assay, DNA damage with comet assay and an in vivo NHEJ activity assay. RESULTS Results showed that only spermatocytes GC-2 transfected with pcDNA-hMSH5P29S vector had significant differences in IR-induced cell survival and apoptosis when compared to that transfected with pcDNA empty vector and pcDNA-wild-hMSH5 vector, while there was no statistical difference in GC-1, TM3, and TM4. In addition, comet assay showed that the DNA damage of GC-2 transfected with pcDNA-hMSH5P29S vector increased significantly compared to that transfected with pcDNA empty vector and pcDNA-wild-hMSH5 vector after IR. And in vivo NHEJ activity assay showed that the NHEJ activity of GC-2 transfected with pcDNA-hMSH5P29S vector was statistically higher than that transfected with pcDNA empty vector and pcDNA-wild-hMSH5 vector. CONCLUSION Our study indicates that the hMSH5 C85T polymorphism leads to an abnormal increase in apoptosis and lessen the control on error-prone NHEJ of spermatocyte GC-2, thereby altering the difference of radiation sensitivity of spermatogenesis.
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Affiliation(s)
- Mingyue Lin
- Department of Laboratory Medicine, The Third Xiangya Hospital, Central South University, Changsha, China.,Department of Laboratory Medicine, Xiangya School of Medicine, Central South University, Changsha, China
| | - Lihuang Guo
- Department of Laboratory Medicine, The Third Xiangya Hospital, Central South University, Changsha, China.,Department of Laboratory Medicine, Xiangya School of Medicine, Central South University, Changsha, China
| | - Zhenbo Cheng
- Department of Laboratory Medicine, The Third Xiangya Hospital, Central South University, Changsha, China.,Department of Laboratory Medicine, Xiangya School of Medicine, Central South University, Changsha, China
| | - Xisha Huan
- Department of Laboratory Medicine, The Third Xiangya Hospital, Central South University, Changsha, China.,Department of Laboratory Medicine, Xiangya School of Medicine, Central South University, Changsha, China
| | - Yue Huang
- Department of Laboratory Medicine, The Third Xiangya Hospital, Central South University, Changsha, China.,Department of Laboratory Medicine, Xiangya School of Medicine, Central South University, Changsha, China
| | - Keqian Xu
- Department of Laboratory Medicine, The Third Xiangya Hospital, Central South University, Changsha, China.,Department of Laboratory Medicine, Xiangya School of Medicine, Central South University, Changsha, China
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3
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Jan SZ, Jongejan A, Korver CM, van Daalen SKM, van Pelt AMM, Repping S, Hamer G. Distinct prophase arrest mechanisms in human male meiosis. Development 2018. [PMID: 29540502 PMCID: PMC6124541 DOI: 10.1242/dev.160614] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
To prevent chromosomal aberrations being transmitted to the offspring, strict meiotic checkpoints are in place to remove aberrant spermatocytes. However, in about 1% of males these checkpoints cause complete meiotic arrest leading to azoospermia and subsequent infertility. Here, we unravel two clearly distinct meiotic arrest mechanisms that occur during prophase of human male meiosis. Type I arrested spermatocytes display severe asynapsis of the homologous chromosomes, disturbed XY-body formation and increased expression of the Y chromosome-encoded gene ZFY and seem to activate a DNA damage pathway leading to induction of p63, possibly causing spermatocyte apoptosis. Type II arrested spermatocytes display normal chromosome synapsis, normal XY-body morphology and meiotic crossover formation but have a lowered expression of several cell cycle regulating genes and fail to silence the X chromosome-encoded gene ZFX. Discovery and understanding of these meiotic arrest mechanisms increases our knowledge of how genomic stability is guarded during human germ cell development. Summary: Histological examination and transcriptomic analysis of human meiosis-arrested spermatocytes reveals two prophase arrest mechanisms, each associated with distinct gene expression profiles implicating the involvement of different biological processes.
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Affiliation(s)
- Sabrina Z Jan
- Center for Reproductive Medicine, Amsterdam Research Institute Reproduction and Development, Academic Medical Center, University of Amsterdam, 1105 AZ, Amsterdam, The Netherlands
| | - Aldo Jongejan
- Bioinformatics Laboratory, Department of Clinical Epidemiology, Biostatistics and Bioinformatics, Academic Medical Center, 1105 AZ, Amsterdam, The Netherlands
| | - Cindy M Korver
- Center for Reproductive Medicine, Amsterdam Research Institute Reproduction and Development, Academic Medical Center, University of Amsterdam, 1105 AZ, Amsterdam, The Netherlands
| | - Saskia K M van Daalen
- Center for Reproductive Medicine, Amsterdam Research Institute Reproduction and Development, Academic Medical Center, University of Amsterdam, 1105 AZ, Amsterdam, The Netherlands
| | - Ans M M van Pelt
- Center for Reproductive Medicine, Amsterdam Research Institute Reproduction and Development, Academic Medical Center, University of Amsterdam, 1105 AZ, Amsterdam, The Netherlands
| | - Sjoerd Repping
- Center for Reproductive Medicine, Amsterdam Research Institute Reproduction and Development, Academic Medical Center, University of Amsterdam, 1105 AZ, Amsterdam, The Netherlands
| | - Geert Hamer
- Center for Reproductive Medicine, Amsterdam Research Institute Reproduction and Development, Academic Medical Center, University of Amsterdam, 1105 AZ, Amsterdam, The Netherlands
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4
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Transcriptional regulation of P63 on the apoptosis of male germ cells and three stages of spermatogenesis in mice. Cell Death Dis 2018; 9:76. [PMID: 29362488 PMCID: PMC5833356 DOI: 10.1038/s41419-017-0046-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 09/06/2017] [Accepted: 10/09/2017] [Indexed: 12/13/2022]
Abstract
Infertility affects 10-15% of couples worldwide, and male factors account for 50%. Spermatogenesis is precisely regulated by genetic factors, and the mutations of genes result in abnormal spermatogenesis and eventual male infertility. The aim of this study was to explore the role and transcriptional regulation of P63 in the apoptosis and mouse spermatogenesis. P63 protein was decreased in male germ cells of P63(+/-) mice compared with wild-type mice. There was no obvious difference in testis weight, sperm motility, and fecundity between P63(+/-) and wild-type mice. However, abnormal germ cells were frequently observed in P63(+/-) mice at 2 months old. Notably, apoptotic male germ cells and the percentage of abnormal sperm were significantly enhanced in P63(+/-) mice compared to wild-type mice. Spermatogonia, pachytene spermatocytes and round spermatids were isolated from P63(+/-) and wild-type mice using STA-PUT velocity sedimentation, and they were identified phenotypically with high purities. RNA sequencing demonstrated distinct transcription profiles in spermatogonia, pachytene spermatocytes, and round spermatids between P63(+/-) mice and wild-type mice. In total, there were 645 differentially expressed genes (DEGs) in spermatogonia, 106 DEGs in pachytene spermatocytes, and 1152 in round spermatids between P63(+/-) mice and wild-type mice. Real time PCR verified a number of DEGs identified by RNA sequencing. Gene ontology annotation and pathway analyzes further indicated that certain key genes, e.g., Ccnd2, Tgfa, Hes5, Insl3, Kit, Lef1, and Jun were involved in apoptosis, while Dazl, Kit, Pld6, Cdkn2d, Stra8, and Ubr2 were associated with regulating spermatogenesis. Collectively, these results implicate that P63 mediates the apoptosis of male germ cells and regulates three stages of spermatogenesis transcriptionally. This study could provide novel targets for the diagnosis and treatment of male infertility.
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5
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Gebel J, Tuppi M, Krauskopf K, Coutandin D, Pitzius S, Kehrloesser S, Osterburg C, Dötsch V. Control mechanisms in germ cells mediated by p53 family proteins. J Cell Sci 2017:jcs.204859. [PMID: 28794013 DOI: 10.1242/jcs.204859] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Germ cells are totipotent and, in principle, immortal as they are the source for new germ cells in each generation. This very special role requires tight quality control systems. The p53 protein family constitutes one of the most important quality surveillance systems in cells. Whereas p53 has become famous for its role as the guardian of the genome in its function as the most important somatic tumor suppressor, p63 has been nicknamed 'guardian of the female germ line'. p63 is strongly expressed in resting oocytes and responsible for eliminating those that carry DNA double-strand breaks. The third family member, p73, acts later during oocyte and embryo development by ensuring correct assembly of the spindle assembly checkpoint. In addition to its role in the female germ line, p73 regulates cell-cell contacts between developing sperm cells and supporting somatic cells in the male germ line. Here, we review the involvement of the p53 protein family in the development of germ cells with a focus on quality control in the female germ line and discuss medical implications for cancer patients.
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Affiliation(s)
- Jakob Gebel
- Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, Max von Laue-Str. 9, Frankfurt am Main 60438, Germany
| | - Marcel Tuppi
- Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, Max von Laue-Str. 9, Frankfurt am Main 60438, Germany
| | - Katharina Krauskopf
- Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, Max von Laue-Str. 9, Frankfurt am Main 60438, Germany
| | - Daniel Coutandin
- Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, Max von Laue-Str. 9, Frankfurt am Main 60438, Germany
| | - Susanne Pitzius
- Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, Max von Laue-Str. 9, Frankfurt am Main 60438, Germany
| | - Sebastian Kehrloesser
- Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, Max von Laue-Str. 9, Frankfurt am Main 60438, Germany
| | - Christian Osterburg
- Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, Max von Laue-Str. 9, Frankfurt am Main 60438, Germany
| | - Volker Dötsch
- Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, Max von Laue-Str. 9, Frankfurt am Main 60438, Germany
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6
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Marcet-Ortega M, Pacheco S, Martínez-Marchal A, Castillo H, Flores E, Jasin M, Keeney S, Roig I. p53 and TAp63 participate in the recombination-dependent pachytene arrest in mouse spermatocytes. PLoS Genet 2017; 13:e1006845. [PMID: 28617799 PMCID: PMC5491309 DOI: 10.1371/journal.pgen.1006845] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 06/29/2017] [Accepted: 06/01/2017] [Indexed: 01/09/2023] Open
Abstract
To protect germ cells from genomic instability, surveillance mechanisms ensure meiosis occurs properly. In mammals, spermatocytes that display recombination defects experience a so-called recombination-dependent arrest at the pachytene stage, which relies on the MRE11 complex—ATM—CHK2 pathway responding to unrepaired DNA double-strand breaks (DSBs). Here, we asked if p53 family members—targets of ATM and CHK2—participate in this arrest. We bred double-mutant mice combining a mutation of a member of the p53 family (p53, TAp63, or p73) with a Trip13 mutation. Trip13 deficiency triggers a recombination-dependent response that arrests spermatocytes in pachynema before they have incorporated the testis-specific histone variant H1t into their chromatin. We find that deficiency for either p53 or TAp63, but not p73, allowed spermatocytes to progress further into meiotic prophase despite the presence of numerous unrepaired DSBs. Even so, the double mutant spermatocytes apoptosed at late pachynema because of sex body deficiency; thus p53 and TAp63 are dispensable for arrest caused by sex body defects. These data affirm that recombination-dependent and sex body-deficient arrests occur via genetically separable mechanisms. Meiosis is a specialized cell division that generates haploid gametes by halving chromosome content through two consecutive rounds of chromosome segregation. At the onset of the first meiotic division, SPO11 protein introduces double-strand breaks (DSBs) throughout the genome. These DSBs are repaired through homologous recombination, which promotes pairing and synapsis of the homologous chromosomes. Some DSBs will become repaired as crossovers, providing a physical connection between the homologous chromosomes which promotes correct chromosome segregation. In fact, recombination defects can lead to formation of aneuploid gametes, one of the major causes of miscarriages and chromosome abnormalities in humans. To protect germ cells from genomic instability and to produce balanced gametes, surveillance mechanisms ensure that meiosis occurs properly. It is known that in the presence of unrepaired DSBs a control mechanism promotes a spermatogenic block at the pachytene stage. Here we describe that, downstream MRE11-ATM-CHK2 pathway, p53 and TAp63 are the effectors responsible for activating recombination-dependent arrest in mouse spermatocytes.
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Affiliation(s)
- Marina Marcet-Ortega
- Genome Integrity and Instability Group, Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona, Spain
- Department of Cell Biology, Physiology and Immunology, Cytology and Histology Unit, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona, Spain
| | - Sarai Pacheco
- Genome Integrity and Instability Group, Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona, Spain
- Department of Cell Biology, Physiology and Immunology, Cytology and Histology Unit, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona, Spain
| | - Ana Martínez-Marchal
- Genome Integrity and Instability Group, Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona, Spain
- Department of Cell Biology, Physiology and Immunology, Cytology and Histology Unit, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona, Spain
| | - Helena Castillo
- Genome Integrity and Instability Group, Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona, Spain
- Department of Cell Biology, Physiology and Immunology, Cytology and Histology Unit, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona, Spain
| | - Elsa Flores
- Department of Biochemistry and Molecular Biology, Graduate School of Biomedical Sciences, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, United States of America
| | - Maria Jasin
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York, United States of America
| | - Scott Keeney
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York, United States of America
- Howard Hughes Medical Institute, Memorial Sloan Kettering Cancer Center, New York, New York, United States of America
| | - Ignasi Roig
- Genome Integrity and Instability Group, Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona, Spain
- Department of Cell Biology, Physiology and Immunology, Cytology and Histology Unit, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona, Spain
- * E-mail:
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7
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56Fe ion irradiation induced apoptosis through Nrf2 pathway in mouse testis. Life Sci 2016; 157:32-37. [DOI: 10.1016/j.lfs.2016.05.043] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 05/19/2016] [Accepted: 05/30/2016] [Indexed: 12/18/2022]
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8
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Zhu Y, Gao G, Xia L, Li X, Wu X, Her C, Xu K. The polymorphichMSH5C85T allele augments radiotherapy-induced spermatogenic impairment. Andrology 2016; 4:873-9. [DOI: 10.1111/andr.12203] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 03/28/2016] [Accepted: 03/29/2016] [Indexed: 11/29/2022]
Affiliation(s)
- Y. Zhu
- Department of Laboratory Medicine; Xiangya School of Medicine; Central South University; Changsha China
| | - G. Gao
- Department of Laboratory Medicine; Xiangya School of Medicine; Central South University; Changsha China
| | - L. Xia
- Department of Tumor; The Third Xiangya Hospital; Central South University; Changsha China
| | - X. Li
- Department of Tumor; The Third Xiangya Hospital; Central South University; Changsha China
| | - X. Wu
- School of Molecular Biosciences; Washington State University; Pullman WA USA
| | - C. Her
- School of Molecular Biosciences; Washington State University; Pullman WA USA
| | - K. Xu
- Department of Laboratory Medicine; Xiangya School of Medicine; Central South University; Changsha China
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9
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Ji X, Huang Q, Yu L, Nussinov R, Ma B. Bioinformatics study of cancer-related mutations within p53 phosphorylation site motifs. Int J Mol Sci 2014; 15:13275-98. [PMID: 25075982 PMCID: PMC4159794 DOI: 10.3390/ijms150813275] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Revised: 07/23/2014] [Accepted: 07/24/2014] [Indexed: 02/06/2023] Open
Abstract
p53 protein has about thirty phosphorylation sites located at the N- and C-termini and in the core domain. The phosphorylation sites are relatively less mutated than other residues in p53. To understand why and how p53 phosphorylation sites are rarely mutated in human cancer, using a bioinformatics approaches, we examined the phosphorylation site and its nearby flanking residues, focusing on the consensus phosphorylation motif pattern, amino-acid correlations within the phosphorylation motifs, the propensity of structural disorder of the phosphorylation motifs, and cancer mutations observed within the phosphorylation motifs. Many p53 phosphorylation sites are targets for several kinases. The phosphorylation sites match 17 consensus sequence motifs out of the 29 classified. In addition to proline, which is common in kinase specificity-determining sites, we found high propensity of acidic residues to be adjacent to phosphorylation sites. Analysis of human cancer mutations in the phosphorylation motifs revealed that motifs with adjacent acidic residues generally have fewer mutations, in contrast to phosphorylation sites near proline residues. p53 phosphorylation motifs are mostly disordered. However, human cancer mutations within phosphorylation motifs tend to decrease the disorder propensity. Our results suggest that combination of acidic residues Asp and Glu with phosphorylation sites provide charge redundancy which may safe guard against loss-of-function mutations, and that the natively disordered nature of p53 phosphorylation motifs may help reduce mutational damage. Our results further suggest that engineering acidic amino acids adjacent to potential phosphorylation sites could be a p53 gene therapy strategy.
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Affiliation(s)
- Xiaona Ji
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200433, China.
| | - Qiang Huang
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200433, China.
| | - Long Yu
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200433, China.
| | - Ruth Nussinov
- Basic Science Program, Leidos Biomedical Research, Inc., Cancer and Inflammation Program, National Cancer Institute, Frederick, MD 21702, USA.
| | - Buyong Ma
- Basic Science Program, Leidos Biomedical Research, Inc., Cancer and Inflammation Program, National Cancer Institute, Frederick, MD 21702, USA.
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10
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Catlin NR, Huse SM, Boekelheide K. The stage-specific testicular germ cell apoptotic response to low-dose X-irradiation and 2,5-hexanedione combined exposure. I: Validation of the laser capture microdissection method for qRT-PCR array application. Toxicol Pathol 2014; 42:1221-8. [PMID: 24717900 DOI: 10.1177/0192623314526319] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Over the past decade, laser capture microdissection (LCM) has grown as a tool for gene expression profiling of small numbers of cells from tumor samples and of specific cell populations in complex tissues. LCM can be used to study toxicant effects on selected cell populations within the testis at different stages of spermatogenesis. There are several LCM-related hurdles to overcome, including issues inherent to the method itself, as well as biases that result from amplifying the LCM-isolated RNA. Many technical issues associated with the LCM method are addressed here, including increasing RNA yield and obtaining more accurate quantification of RNA yields. We optimized the LCM method optimized to generate RNA quantities sufficient for quantitative reverse transcription polymerase chain reaction (qRT-PCR) array analysis without amplification and were able to validate the method through direct comparison of results from unamplified and amplified RNA from individual samples. The addition of an amplification step for gene expression studies using LCM RNA resulted in a bias, especially for low abundance transcripts. Although the amplification bias was consistent across samples, researchers should use caution when comparing results generated from amplified and unamplified LCM RNA. Here, we have validated the use of LCM-derived RNA with the qRT-PCR array, improving our ability to investigate cell-type and stage-specific responses to toxicant exposures.
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Affiliation(s)
- Natasha R Catlin
- Department of Pathology and Laboratory Medicine, Brown University, Providence, Rhode Island, USA
| | - Susan M Huse
- Department of Pathology and Laboratory Medicine, Brown University, Providence, Rhode Island, USA
| | - Kim Boekelheide
- Department of Pathology and Laboratory Medicine, Brown University, Providence, Rhode Island, USA
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11
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TAp73 is required for spermatogenesis and the maintenance of male fertility. Proc Natl Acad Sci U S A 2014; 111:1843-8. [PMID: 24449892 DOI: 10.1073/pnas.1323416111] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The generation of viable sperm proceeds through a series of coordinated steps, including germ cell self-renewal, meiotic recombination, and terminal differentiation into functional spermatozoa. The p53 family of transcription factors, including p53, p63, and p73, are critical for many physiological processes, including female fertility, but little is known about their functions in spermatogenesis. Here, we report that deficiency of the TAp73 isoform, but not p53 or ΔNp73, results in male infertility because of severe impairment of spermatogenesis. Mice lacking TAp73 exhibited increased DNA damage and cell death in spermatogonia, disorganized apical ectoplasmic specialization, malformed spermatids, and marked hyperspermia. We demonstrated that TAp73 regulates the mRNA levels of crucial genes involved in germ stem/progenitor cells (CDKN2B), spermatid maturation/spermiogenesis (metalloproteinase and serine proteinase inhibitors), and steroidogenesis (CYP21A2 and progesterone receptor). These alterations of testicular histology and gene expression patterns were specific to TAp73 null mice and not features of mice lacking p53. Our work provides previously unidentified in vivo evidence that TAp73 has a unique role in spermatogenesis that ensures the maintenance of mitotic cells and normal spermiogenesis. These results may have implications for the diagnosis and management of human male infertility.
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12
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Wang ZC, Wang JF, Li YB, Guo CX, Liu Y, Fang F, Gong SL. Involvement of endoplasmic reticulum stress in apoptosis of testicular cells induced by low-dose radiation. ACTA ACUST UNITED AC 2013; 33:551-558. [PMID: 23904376 DOI: 10.1007/s11596-013-1157-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Revised: 12/12/2012] [Indexed: 02/04/2023]
Abstract
The study examined the role of endoplasmic reticulum stress (ERS) and signaling pathways of inositol-requiring enzyme-1 (IRE1), RNA-activated protein kinase-like ER kinase (PERK) and activating transcription factor-6 (ATF6) in apoptosis of mouse testicular cells treated with low-dose radiation (LDR). In the dose-dependent experiment, the mice were treated with whole-body X-ray irradiation at different doses (25, 50, 75, 100 or 200 mGy) and sacrificed 12 h later. In the time-dependent experiment, the mice were exposed to 75 mGy X-ray irradiation and killed at different time points (3, 6, 12, 18 or 24 h). Testicular cells were harvested for experiments. H(2)O(2) and NO concentrations, and Ca(2+)-ATPase activity were detected by biochemical assays, the calcium ion concentration ([Ca(2+)]i) by flow cytometry using fluo-3 probe, and GRP78 mRNA and protein expressions by quantitative real-time RT-PCR (qRT-PCR) and Western blotting, respectively. The mRNA expressions of S-XBP1, JNK, caspase-12 and CHOP were measured by qRT-PCR, and the protein expressions of IRE1α, S-XBP1, p-PERK, p-eIF2α, ATF6 p50, p-JNK, pro-caspase-12, cleaved caspase-12 and CHOP by Western blotting. The results showed that the concentrations of H2O2 and NO, the mRNA expressions of GRP78, S-XBP1, JNK, caspase-12 and CHOP, and the protein expressions of GRP78, S-XBP1, IRE1α, p-PERK, p-eIF2α, ATF6 p50, p-JNK, pro-caspase-12, cleaved caspase-12 and CHOP were significantly increased in a time- and dose-dependent manner after LDR. But the [Ca(2+)]i and Ca(2+)-ATPase activities were significantly decreased in a time- and dose-dependent manner. It was concluded that the ERS, regulated by IRE1, PERK and ATF6 pathways, is involved in the apoptosis of testicular cells in LDR mice, which is associated with ERS-apoptotic signaling molecules of JNK, caspase-12 and CHOP.
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Affiliation(s)
- Zhi-Cheng Wang
- Key Laboratory of Radiobiology of Ministry of Health, School of Public Health, Jilin University, Changchun, 130021, China
| | - Jian-Feng Wang
- Key Laboratory of Radiobiology of Ministry of Health, School of Public Health, Jilin University, Changchun, 130021, China
| | - Yan-Bo Li
- Key Laboratory of Radiobiology of Ministry of Health, School of Public Health, Jilin University, Changchun, 130021, China.,School of Public Health and Family Medicine, Capital Medical University, Beijing, 100069, China
| | - Cai-Xia Guo
- School of Public Health and Family Medicine, Capital Medical University, Beijing, 100069, China
| | - Yang Liu
- Key Laboratory of Radiobiology of Ministry of Health, School of Public Health, Jilin University, Changchun, 130021, China
| | - Fang Fang
- Key Laboratory of Radiobiology of Ministry of Health, School of Public Health, Jilin University, Changchun, 130021, China.
| | - Shou-Liang Gong
- Key Laboratory of Radiobiology of Ministry of Health, School of Public Health, Jilin University, Changchun, 130021, China.
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Xu J, Escamilla J, Mok S, David J, Priceman S, West B, Bollag G, McBride W, Wu L. CSF1R signaling blockade stanches tumor-infiltrating myeloid cells and improves the efficacy of radiotherapy in prostate cancer. Cancer Res 2013; 73:2782-94. [PMID: 23418320 DOI: 10.1158/0008-5472.can-12-3981] [Citation(s) in RCA: 453] [Impact Index Per Article: 41.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Radiotherapy is used to treat many types of cancer, but many treated patients relapse with local tumor recurrence. Tumor-infiltrating myeloid cells (TIM), including CD11b (ITGAM)(+)F4/80 (EMR1)+ tumor-associated macrophages (TAM), and CD11b(+)Gr-1 (LY6G)+ myeloid-derived suppressor cells (MDSC), respond to cancer-related stresses and play critical roles in promoting tumor angiogenesis, tissue remodeling, and immunosuppression. In this report, we used a prostate cancer model to investigate the effects of irradiation on TAMs and MDSCs in tumor-bearing animals. Unexpectedly, when primary tumor sites were irradiated, we observed a systemic increase of MDSCs in spleen, lung, lymph nodes, and peripheral blood. Cytokine analysis showed that the macrophage colony-stimulating factor CSF1 increased by two-fold in irradiated tumors. Enhanced macrophage migration induced by conditioned media from irradiated tumor cells was completely blocked by a selective inhibitor of CSF1R. These findings were confirmed in patients with prostate cancer, where serum levels of CSF1 increased after radiotherapy. Mechanistic investigations revealed the recruitment of the DNA damage-induced kinase ABL1 into cell nuclei where it bound the CSF1 gene promoter and enhanced CSF1 gene transcription. When added to radiotherapy, a selective inhibitor of CSF1R suppressed tumor growth more effectively than irradiation alone. Our results highlight the importance of CSF1/CSF1R signaling in the recruitment of TIMs that can limit the efficacy of radiotherapy. Furthermore, they suggest that CSF1 inhibitors should be evaluated in clinical trials in combination with radiotherapy as a strategy to improve outcomes.
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Affiliation(s)
- Jingying Xu
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California 90095-1735, USA
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14
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Moreno RD, Urriola-Muñoz P, Lagos-Cabré R. The emerging role of matrix metalloproteases of the ADAM family in male germ cell apoptosis. SPERMATOGENESIS 2011; 1:195-208. [PMID: 22319668 DOI: 10.4161/spmg.1.3.17894] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Revised: 08/27/2011] [Accepted: 08/29/2011] [Indexed: 02/06/2023]
Abstract
Constitutive germ cell apoptosis during mammalian spermatogenesis is a key process for controlling sperm output and to eliminate damaged or unwanted cells. An increase or decrease in the apoptosis rate has deleterious consequences and leads to low sperm production. Apoptosis in spermatogenesis has been widely studied, but the mechanism by which it is induced under physiological or pathological conditions has not been clarified. We have recently identified the metalloprotease ADAM17 (TACE) as a putative physiological inducer of germ cell apoptosis. The mechanisms involved in regulating the shedding of the ADAM17 extracellular domain are still far from being understood, although they are important in order to understand cell-cell communications. Here, we review the available data regarding apoptosis during mammalian spermatogenesis and the localization of ADAM proteins in the male reproductive tract. We propose an integrative working model where ADAM17, p38 MAPK, protein kinase C (PKC) and the tyrosine kinase c-Abl participate in the physiological signalling cascade inducing apoptosis in germ cells. In our model, we also propose a role for the Sertoli cell in regulating the Fas/FasL system in order to induce the extrinsic pathway of apoptosis in germ cells. This working model could be applied to further understand constitutive apoptosis in spermatogenesis and in pathological conditions (e.g., varicocele) or following environmental toxicants exposure (e.g., genotoxicity or xenoestrogens).
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Affiliation(s)
- Ricardo D Moreno
- Departamento de Fisiología; Pontificia Universidad Católica de Chile; Santiago, Chile
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15
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Bornstein C, Brosh R, Molchadsky A, Madar S, Kogan-Sakin I, Goldstein I, Chakravarti D, Flores ER, Goldfinger N, Sarig R, Rotter V. SPATA18, a spermatogenesis-associated gene, is a novel transcriptional target of p53 and p63. Mol Cell Biol 2011; 31:1679-89. [PMID: 21300779 PMCID: PMC3126342 DOI: 10.1128/mcb.01072-10] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2010] [Accepted: 01/29/2011] [Indexed: 12/18/2022] Open
Abstract
The transcription factor p53 functions not only to suppress tumorigenesis but also to maintain normal development and homeostasis. Although p53 was implicated in different aspects of fertility, including spermatogenesis and implantation, the mechanism underlying p53 involvement in spermatogenesis is poorly resolved. In this study we describe the identification of a spermatogenesis-associated gene, SPATA18, as a novel p53 transcriptional target and show that SPATA18 transcription is induced by p53 in a variety of cell types of both human and mouse origin. p53 binds a consensus DNA motif that resides within the first intron of SPATA18. We describe the spatiotemporal expression patterns of SPATA18 in mouse seminiferous tubules and suggest that SPATA18 transcription is regulated in vivo by p53. We also demonstrate the induction of SPATA18 by p63 and suggest that p63 can compensate for the loss of p53 activity in vivo. Our data not only enrich the known collection of p53 targets but may also provide insights on spermatogenesis defects that are associated with p53 deficiency.
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Affiliation(s)
- Chamutal Bornstein
- Department of Molecular Cell Biology, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Ran Brosh
- Department of Molecular Cell Biology, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Alina Molchadsky
- Department of Molecular Cell Biology, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Shalom Madar
- Department of Molecular Cell Biology, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Ira Kogan-Sakin
- Department of Molecular Cell Biology, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Ido Goldstein
- Department of Molecular Cell Biology, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Deepavali Chakravarti
- Department of Molecular and Cellular Oncology, Graduate School of Biomedical Sciences, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030
| | - Elsa R. Flores
- Department of Molecular and Cellular Oncology, Graduate School of Biomedical Sciences, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030
| | - Naomi Goldfinger
- Department of Molecular Cell Biology, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Rachel Sarig
- Department of Molecular Cell Biology, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Varda Rotter
- Department of Molecular Cell Biology, The Weizmann Institute of Science, Rehovot 76100, Israel
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16
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Yu JJ, Jiang YC. Association of testicular p63 expression and spermatogenesis in androgen receptor knockout (ARKO) mice. Aging Male 2011; 14:72-5. [PMID: 20670103 DOI: 10.3109/13685538.2010.487922] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVE To study changes of testicular p63 expression and its effect on spermatogenic function in seminiferous tubules in androgen receptor knockout (ARKO) mice. METHODS A total of 28 ARKO mice (ARKO group) screened by Cre-lox and 28 male Wistar mice without ARKO (controlled group) were enrolled in our study. Route pathology was performed and p63 examination was detected by immunohistochemistry in testes. Linear correlations were used to explore potential associations between p63 protein expression and spermatogenic function (TMS score). RESULTS In ARKO group, inner diameter of seminiferous tubules was decreased (62 +/- 1.3 microm vs. 91 +/- 1.2 microm), thickness of the basal membrane of the tubules (4 +/- 0.3 microm vs. 2.7 +/- 0.5 microm), cellular population within tubules was reduced (2 +/- 0.4 vs. 4 +/- 0.1 layers), degree of spermatogenesis within the tubules turned to disturbance (3 +/- 1.0 vs. 5 +/- 0.1), Testicular Makler score was lower than controlled group (7 +/- 0.2 vs.15 +/- 0.3), they had significant differences (p <0.01). P63 expressed significantly lower in ARKO group than that in Wistar group, and was limited at stages from spermatocyte to round spermatid. (Percentage of positive cells ? 68.1 +/- 3.7 vs. 81.7 +/- 5.1, p<0.001). The HSCORE yielded similar results (HSCORE 3.7 +/- 0.3 vs. 2.0 +/- 0.2, p<0.001). p63 protein expression was significantly positively correlated with spermatogenic function (r=0.87, p<0.01). CONCLUSIONS p63 developed important effect on spermatogenesis and the regulatory effect of p63 on spermatogenesis mainly occurred in the early stage of spermiogenesis in testis.
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Affiliation(s)
- Jian Jun Yu
- Shang Hai 6th People's Hospital, Shang Hai Jiaotong University, Shang Hai 200233, China.
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17
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Allington TM, Schiemann WP. The Cain and Abl of epithelial-mesenchymal transition and transforming growth factor-β in mammary epithelial cells. Cells Tissues Organs 2010; 193:98-113. [PMID: 21051857 DOI: 10.1159/000320163] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Transforming growth factor-β (TGF-β) normally inhibits breast cancer development by preventing mammary epithelial cell (MEC) proliferation, by inducing MEC apoptosis, and by creating cell microenvironments that maintain MEC homeostasis and prevent their uncontrolled growth and motility. Mammary tumorigenesis elicits dramatic alterations in MEC architecture and microenvironment integrity, which collectively counteract the tumor-suppressing activities of TGF-β and enable its stimulation of breast cancer invasion and metastasis. How malignant MECs overcome the cytostatic actions imposed by normal microenvironments and TGF-β, and how abnormal microenvironments conspire with TGF-β to stimulate the development and progression of mammary tumors remains largely undefined. These knowledge gaps have prevented science and medicine from implementing treatments effective in simultaneously targeting abnormal cellular microenvironments, and in antagonizing the oncogenic activities of TGF-β in developing and progressing breast cancers. c-Abl is a ubiquitously expressed nonreceptor protein tyrosine kinase that essentially oversees all aspects of cell physiology, including the regulation of cell proliferation, migration and adhesion, as well as that of cell survival. Thus, the biological functions of c-Abl are highly reminiscent of those attributed to TGF-β, including the ability to function as either a suppressor or promoter of tumorigenesis. Interestingly, while dysregulated Abl activity clearly promotes tumorigenesis in hematopoietic cells, an analogous role for c-Abl in regulating solid tumor development, including those of the breast, remains controversial. Here, we review the functions of c-Abl in regulating breast cancer development and progression, and in alleviating the oncogenic activities of TGF-β and its stimulation of epithelial-mesenchymal transition during mammary tumorigenesis.
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Affiliation(s)
- Tressa M Allington
- Department of Pharmacology, Anschutz Medical Campus, University of Colorado Denver, Aurora, Colo., USA
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18
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Codelia VA, Cisterna M, Alvarez AR, Moreno RD. p73 participates in male germ cells apoptosis induced by etoposide. Mol Hum Reprod 2010; 16:734-42. [DOI: 10.1093/molehr/gaq045] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
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19
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Abstract
Spermatogenesis is a cyclic process during which, within each epithelial area, various generations of germ cells undergo a series of developmental steps according to a fixed time schedule. The cycle of the seminiferous epithelium can be subdivided into stages. In the mouse, 12 such stages have been described that can be distinguished from one another by steps in spermatid development. The best way to recognize the stages in seminiferous tubule cross-sections is to use Bouin's-fixed testes of normal mice and sections stained with the Periodic acid Schiff (PAS) technique and hematoxylin. Unfortunately, this is not always possible. Sometimes PAS staining cannot be used, such as when immunohistochemistry is carried out. Moreover, not all germ cell types may be present in some instances, as in young or mutant mice. We summarize here all stage-identifying criteria that can be used in the ideal situation as well as in hematoxylin-only stained sections and/or when germ cell types are missing.
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Affiliation(s)
- Emad A Ahmed
- Department of Endocrinology, Utrecht University, Utrecht, The Netherlands
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20
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Forand A, Bernardino-Sgherri J. A critical role of PUMA in maintenance of genomic integrity of murine spermatogonial stem cell precursors after genotoxic stress. Cell Res 2009; 19:1018-30. [PMID: 19417777 DOI: 10.1038/cr.2009.50] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Neonatal gonocytes are precursors of spermatogonial stem cells. Preserving their integrity by elimination of damaged germ cells may be crucial to avoid the transmission of genetic alterations to progeny. Using gamma-irradiation, we investigated by immunohistochemistry, flow cytometry and real-time PCR components of the death machinery in neonatal gonocytes. Their death was correlated with caspase 3 activation but not with AIF translocation into the nucleus. The in vivo contribution of both the extrinsic and the intrinsic pathways was then investigated. We focused on the roles of TRAIL/Death Receptor 5 (DR5) and PUMA. Our results were validated using knockout mice. Whereas DR5 expression was upregulated at the cell surface after radiation, caspase 8 was not activated. However, we detected caspase 9 cleavage associated with cytochrome c release. In mice deficient for PUMA, radiation-induced gonocyte apoptosis was reduced, whereas invalidation of TRAIL had no effect. Overall, our results show that genotoxic stress-induced apoptosis of gonocytes is caspase-dependent and involves almost exclusively the intrinsic pathway. Furthermore, PUMA plays a critical role in the maintenance of genomic integrity of spermatogonial stem cell precursors.
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Affiliation(s)
- Anne Forand
- CEA, DSV, iRCM, SCSR, Laboratory of Differentiation and Radiobiology of Gonads, Fontenay aux Roses F-92265, France
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21
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Allington TM, Galliher-Beckley AJ, Schiemann WP. Activated Abl kinase inhibits oncogenic transforming growth factor-beta signaling and tumorigenesis in mammary tumors. FASEB J 2009; 23:4231-43. [PMID: 19690215 DOI: 10.1096/fj.09-138412] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Transforming growth factor-beta (TGF-beta) is a ubiquitous cytokine with dual roles in tumor suppression and promotion, and these dichotomous functions have frustrated the development of therapies targeting oncogenic signaling by TGF-beta. In comparison, Abl is well established as an initiator of hematopoietic cancers; however, a clear role for Abl in regulating solid tumor development remains elusive. Here, we investigated the role of Abl in TGF-beta-mediated epithelial-mesenchymal transition (EMT) in normal and metastatic mammary epithelial cells (MECs). In doing so, we identified Abl as an essential regulator of MEC morphology and showed that Abl inactivation was sufficient to induce phenotypic and transcriptional EMT in normal MECs. Increasing Abl activity in metastatic MECs resulted in their complete morphological reversion, restored their cytostatic response to TGF-beta, and blocked their secretion of matrix metalloproteinases induced by TGF-beta. Constitutively active Abl expression blocked TGF-beta-responsive mammary tumor growth in mice, while Imatinib therapy afforded no clinical benefit in mice bearing mammary tumors. Collectively, this investigation establishes Abl as a potent mediator of MEC identity, and as a suppressor of oncogenic TGF-beta signaling during mammary tumorigenesis. Notably, our findings strongly caution against the use of pharmacological Abl antagonists in the treatment of developing and progressing mammary tumors.
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Affiliation(s)
- Tressa M Allington
- Department of Pharmacology, MS-8303, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
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22
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Tompkins JD, Wu X, Chu YL, Her C. Evidence for a direct involvement of hMSH5 in promoting ionizing radiation induced apoptosis. Exp Cell Res 2009; 315:2420-32. [PMID: 19442657 DOI: 10.1016/j.yexcr.2009.05.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2008] [Revised: 04/06/2009] [Accepted: 05/06/2009] [Indexed: 10/20/2022]
Abstract
Although increasing evidence has suggested that the hMSH5 protein plays an important role in meiotic and mitotic DNA recombinational repair, its precise functions in recombination and DNA damage response are presently elusive. Here we show that the interaction between hMSH5 and c-Abl confers ionizing radiation (IR)-induced apoptotic response by promoting c-Abl activation and p73 accumulation, and these effects are greatly enhanced in cells expressing hMSH5(P29S) (i.e. the hMSH5 variant possessing a proline to serine change within the N-terminal (Px)(5) dipeptide repeat). Our current study provides the first evidence that the (Px)(5) dipeptide repeat plays an important role in modulating the interaction between hMSH5 and c-Abl and alteration of this dipeptide repeat in hMSH5(P29S) leads to increased IR sensitivity owing to enhanced caspase-3-mediated apoptosis. In addition, RNAi-mediated hMSH5 silencing leads to the reduction of apoptosis in IR-treated cells. In short, this study implicates a role for hMSH5 in DNA damage response involving c-Abl and p73, and suggests that mutations impairing this process could significantly affect normal cellular responses to anti-cancer treatments.
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Affiliation(s)
- Joshua D Tompkins
- School of Molecular Biosciences and Center for Reproductive Biology, PO Box 644660, Washington State University, Pullman, WA 99164-4660, USA
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23
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Liu G, Gong P, Bernstein LR, Bi Y, Gong S, Cai L. Apoptotic Cell Death Induced by Low-Dose Radiation in Male Germ Cells: Hormesis and Adaptation. Crit Rev Toxicol 2008; 37:587-605. [PMID: 17674213 DOI: 10.1080/10408440701493061] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Biological effects of low-dose radiation (LDR) in somatic cells have captured the interest of radiobiologists for the last two decades. Apoptosis of germ cells is required for normal spermatogenesis and often occurs through highly conserved events, including the transfer of vital cellular materials to the growing gametes following death of neighboring cells. Apoptosis of germ cells also functions in diverse processes, including removal of abnormal or superfluous cells at specific checkpoints, establishment of caste differentiation, and individualization of gametes. Moreover, germ cells are very sensitive to radiation-induced genomic and cytological effects. Therefore, induction of germ-cell apoptosis has been observed in the testis of animals exposed to both high-dose radiation (HDR) and LDR. Exposure of male germ cells to LDR induces a stimulating effect, while exposure to HDR causes an inhibitory effect on the metabolism, antioxidant capacity, and proliferation and maturation of cells, a phenomenon termed hormesis. Preexposure to LDR also protects cells from subsequently HDR-induced genomic and cytological effects, a phenomenon termed adaptive response. This review describes the features of male germ-cell apoptosis. It reviews the evidence that LDR induces the hormesis and adaptive responses in the male germ cells in terms of apoptosis. This review also discusses the possible effects of LDR-induced apoptotic hormesis and adaptive response on the modulation of inheritable genomic damage caused by subsequent radiation exposure to male germ cells.
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Affiliation(s)
- Guangwei Liu
- Ministry of Health Radiobiology Research Unit, School of Public Health, Jilin University, Changchun, China
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24
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Vilgelm A, El-Rifai W, Zaika A. Therapeutic prospects for p73 and p63: rising from the shadow of p53. Drug Resist Updat 2008; 11:152-63. [PMID: 18801697 DOI: 10.1016/j.drup.2008.08.001] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2008] [Revised: 08/06/2008] [Accepted: 08/11/2008] [Indexed: 01/15/2023]
Abstract
The p53 protein family consists of three transcription factors: p53, p63, and p73. These proteins share significant structural and functional similarities and each has unique biological functions as well. Although the role of p53 in cellular stress is extensively studied, many questions remain about p63 and p73. In this review we summarize current data on functional interactions within the p53 family, their regulation and roles in response to genotoxic stress. We also discuss the significance of p73 and p63 for cancer therapy and outline novel approaches in development of therapeutic drugs that specifically target the p53 family.
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Affiliation(s)
- Anna Vilgelm
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN 37232, United States
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25
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Hamer G, Wang H, Bolcun-Filas E, Cooke HJ, Benavente R, Höög C. Progression of meiotic recombination requires structural maturation of the central element of the synaptonemal complex. J Cell Sci 2008; 121:2445-51. [PMID: 18611960 DOI: 10.1242/jcs.033233] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The synaptonemal complex is an elaborate meiosis-specific supramolecular protein assembly that promotes chromosome synapsis and meiotic recombination. We inactivated the meiosis-specific gene Tex12 and found that TEX12 is essential for progression of meiosis in both male and female germ cells. Structural analysis of the synaptonemal complex in Tex12-/- meiocytes revealed a disrupted central element structure, a dense structure residing between the synapsed homologous chromosomes. Chromosome synapsis is initiated at multiple positions along the paired homologous chromosomes in Tex12-/- meiotic cells, but fails to propagate along the chromosomes. Furthermore, although meiotic recombination is initiated in Tex12-/- meiotic cells, these early recombination events do not develop into meiotic crossovers. Hence, the mere initiation of synapsis is not sufficient to support meiotic crossing-over. Our results show that TEX12 is a component of the central element structure of the synaptonemal complex required for propagation of synapsis along the paired homologous chromosomes and maturation of early recombination events into crossovers.
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Affiliation(s)
- Geert Hamer
- Department of Cell and Molecular Biology, Karolinska Institute, Berzelius väg 35, Stockholm, Sweden
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26
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Livera G, Petre-Lazar B, Guerquin MJ, Trautmann E, Coffigny H, Habert R. p63 null mutation protects mouse oocytes from radio-induced apoptosis. Reproduction 2008; 135:3-12. [PMID: 18159078 DOI: 10.1530/rep-07-0054] [Citation(s) in RCA: 121] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Female fertility in mammals is determined by the pool of primordial follicles and low doses of radiation induce a major loss of primordial follicles in the ovary. We investigated the expression of p53 and its homologues, p63 and p73, in the normal and irradiated neonatal ovary. p63 was the only member of the p53 family detected in oocyte nucleus. No p63 transcripts or protein were detected in the early foetal ovary. p63 production began in late pachytene-stage oocytes and peaked in diplotene oocytes in mice and humans. The production of p63 was correlated with meiotic DNA double-strand break repair. Only transactivation (TA) isoforms were present in the ovary, with TAp63 alpha by far the most abundant in terms of mRNA and protein levels. Complete p63 null mutation did not affect normal ovary development. Irradiation rapidly triggered p63 phosphorylation. p63 null mutation prevented the cleavage of caspases-9 and -3 and the follicle loss induced by ionising radiation. Thus, our results evidence that irradiation-induced depletion of the primordial follicle pool results from the activation of p63 in quiescent oocytes.
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Affiliation(s)
- Gabriel Livera
- CEA, DSV/DRR/SEGG/LDRG, Unit of Gametogenesis and Genotoxicity, Laboratory of Differentiation and Radiobiology of the Gonads, F-92265 Fontenay aux Roses Cedex, France.
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27
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Wakatsuki M, Ohno T, Iwakawa M, Ishikawa H, Noda S, Ohta T, Kato S, Tsujii H, Imai T, Nakano T. p73 Protein Expression Correlates With Radiation-Induced Apoptosis in the Lack of p53 Response to Radiation Therapy for Cervical Cancer. Int J Radiat Oncol Biol Phys 2008; 70:1189-94. [DOI: 10.1016/j.ijrobp.2007.08.033] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2006] [Revised: 05/30/2007] [Accepted: 08/05/2007] [Indexed: 01/25/2023]
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28
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Mor I, Sklan EH, Podoly E, Pick M, Kirschner M, Yogev L, Bar-Sheshet Itach S, Schreiber L, Geyer B, Mor T, Grisaru D, Soreq H. Acetylcholinesterase-R increases germ cell apoptosis but enhances sperm motility. J Cell Mol Med 2008; 12:479-95. [PMID: 18194455 PMCID: PMC3822537 DOI: 10.1111/j.1582-4934.2008.00231.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Changes in protein subdomains through alternative splicing often modify protein-protein interactions, altering biological processes. A relevant example is that of the stress-induced up-regulation of the acetylcholinesterase (AChE-R) splice variant, a common response in various tissues. In germ cells of male transgenic TgR mice, AChE-R excess associates with reduced sperm differentiation and sperm counts. To explore the mechanism(s) by which AChE-R up-regulation affects spermatogenesis, we identified AChE-R's protein partners through a yeast two-hybrid screen. In meiotic spermatocytes from TgR mice, we detected AChE-R interaction with the scaffold protein RACK1 and elevated apoptosis. This correlated with reduced scavenging by RACK1 of the pro-apoptotic TAp73, an outcome compatible with the increased apoptosis. In contrast, at later stages in sperm development, AChE-R's interaction with the glycolytic enzyme enolase-α elevates enolase activity. In transfected cells, enforced AChE-R excess increased glucose uptake and adenosine tri-phosphate (ATP) levels. Correspondingly, TgR sperm cells display elevated ATP levels, mitochondrial hyperactivity and increased motility. In human donors' sperm, we found direct association of sperm motility with AChE-R expression. Interchanging interactions with RACK1 and enolase-α may hence enable AChE-R to affect both sperm differentiation and function by participating in independent cellular pathways.
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Affiliation(s)
- I Mor
- The Silberman Institute of Life Sciences, the Hebrew University of Jerusalem, Jerusalem, Israel
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29
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Ludes-Meyers JH, Kil H, Nunñez MI, Conti CJ, Parker-Thornburg J, Bedford MT, Aldaz CM. WWOX hypomorphic mice display a higher incidence of B-cell lymphomas and develop testicular atrophy. Genes Chromosomes Cancer 2007; 46:1129-36. [PMID: 17823927 PMCID: PMC4143238 DOI: 10.1002/gcc.20497] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
WWOX is a putative tumor suppressor gene encoded within common chromosomal fragile site region FRA16D, in chromosome band 16q23. Multiple studies have demonstrated that WWOX expression is often reduced or lost in various tumor types. WWOX tumor suppressor activity was suggested by re-expressing WWOX in breast, ovarian, and lung tumor cell lines leading to tumor growth inhibition in vivo. To determine whether loss of Wwox gene expression has a role in tumorigenesis, we generated a mouse strain containing a Wwox gene mutated by a gene-trap vector. Homozygous Wwox gene-trap mice (Wwox(gt/gt)) had no detectable Wwox protein in most tissues examined, although, a low level could be detected in a minority of tissues. Because of these observations, we concluded that these mice are Wwox hypomorphs. Remarkably, Wwox hypomorphic mice are viable in contrast to the recently reported postnatal lethality of Wwox knockout mice. Testes from Wwox(gt/gt) males had high numbers of atrophic seminiferous tubules and reduced fertility when compared with wild-type counterparts. We observed that the Wwox(gt/gt) mice had a significantly shorter lifespan, and female hypomorphs had a higher incidence of spontaneous B-cell lymphomas. In conclusion, we describe a novel Wwox hypomorphic mouse model that overcomes postnatal lethality that was recently observed in Wwox knockout mice. Therefore, tumorigenesis studies using this model more closely recapitulates the loss of WWOX expression observed in human cancers. Importantly, our observation that Wwox hypomorphs had an increased incidence of B-cell lymphomas supports a role of Wwox as a tumor suppressor.
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Affiliation(s)
- John H. Ludes-Meyers
- Departmentof Carcinogenesis,Universityof Texas M.D. Anderson Cancer Center,Science Park-Research Division, Smithville, Texas 78957
| | - Hyunsuk Kil
- Departmentof Carcinogenesis,Universityof Texas M.D. Anderson Cancer Center,Science Park-Research Division, Smithville, Texas 78957
| | - Maria I. Nunñez
- Departmentof Carcinogenesis,Universityof Texas M.D. Anderson Cancer Center,Science Park-Research Division, Smithville, Texas 78957
| | - Claudio J. Conti
- Departmentof Carcinogenesis,Universityof Texas M.D. Anderson Cancer Center,Science Park-Research Division, Smithville, Texas 78957
| | - Jan Parker-Thornburg
- Departmentof Biochemistry and Molecular Biology,Universityof Texas M.D. Anderson Cancer Center, Houston, Texas 78957
| | - Mark T. Bedford
- Departmentof Carcinogenesis,Universityof Texas M.D. Anderson Cancer Center,Science Park-Research Division, Smithville, Texas 78957
| | - C. Marcelo Aldaz
- Departmentof Carcinogenesis,Universityof Texas M.D. Anderson Cancer Center,Science Park-Research Division, Smithville, Texas 78957
- Correspondence to: C. Marcelo Aldaz, Department of Carcino-genesis, University of Texas M.D. Anderson Cancer Center, Science Park-Research Division, 1808 Park Road 1-C, Smithville, TX 78957, USA.
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Abstract
Transcription factor p63, a member of the tumor suppressor p53 family, plays an important role in epithelial development, and its expression is found in many epithelial tissues. Our previous reports have shown that p63 is expressed in primordial and testicular germ cells. In this study, we investigated the expression and distribution of p63 isoforms (TAp63alpha, TAp63beta, TAp63gamma, DeltaNp63alpha, DeltaNp63beta and DeltaNp63gamma) in the mouse ovary. Reverse transcription-polymerase chain reaction experiments with primers specific for different p63 isoforms demonstrated that transcripts encoding the transactivation domain and alpha isoforms were preferentially expressed in the ovary. Immunolocalization of p63 proteins, presumably that of full-length p63alpha isoform, was observed in the oocytes of primordial, primary and two-layered secondary follicles. However, positive staining was not detected in the oocytes of multi-layered secondary follicles and antral follicles as they continued to develop. This data suggests that p63 may be implicated in the meiosis and cell cycle control of germ cells in the mouse ovary.
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Petre-Lazar B, Moreno SG, Livera G, Duquenne C, Habert R, Coffigny H. p63 expression pattern in foetal and neonatal gonocytes after irradiation and role in the resulting apoptosis by using p63 knockout mice. Int J Radiat Biol 2007; 82:771-80. [PMID: 17148261 DOI: 10.1080/09553000600960019] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
PURPOSE To investigate the role of p63, a member of the p53 family, in gonocyte apoptosis after radiation exposure. MATERIALS AND METHODS Wild-type (WT) and p63 knock-out (KO) testes were exposed in vivo or in vitro to a 3 Gy dose of 137Cesium (137Cs) gamma-rays at day 18.5 post-conception (p.c.). p63 whole expression was studied in neonatal testes by immunohistochemistry, whereas TAp63 and DeltaNp63 isoforms were studied by Reverse-transcribed Polymerase Chain Reaction (RT-PCR). Gonocyte apoptosis was analysed by immunohistochemistry (cleaved caspase 3) and In Situ End labelling (ISEL). RESULTS Such foetal irradiation leads to a strong increase of gonocyte apoptosis in newborns. It also induces the up-regulation of the TAp63alpha isoform and the down-regulation of the DeltaNp63alpha isoform. Moreover, in control p63KO testis, a significant increase in the number of gonocytes was associated with a strong reduction of their apoptosis compared with the control wild-type testis. Unexpectedly, after irradiation this increase of the number of apoptotic gonocytes was seen in p63KO testis, which was comparable to that in irradiated p63WT testis. CONCLUSION We demonstrate that p63 is able to trigger gonocyte apoptosis in control testis but is not necessarily required in their radio-induced apoptosis.
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Affiliation(s)
- B Petre-Lazar
- CEA, Centre de Fontenay-aux-Roses, Laboratory of Differentiation and Radiobiology of Gonads, DSV/DRR/SEGG, Fontenay-aux-Roses, France
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Saito K, Kawakami S, Okada Y, Takazawa R, Koga F, Kageyama Y, Kihara K. Spatial and Isoform Specific p63 Expression in the Male Human Urogenital Tract. J Urol 2006; 176:2268-73. [PMID: 17070310 DOI: 10.1016/j.juro.2006.07.057] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2005] [Indexed: 11/22/2022]
Abstract
PURPOSE A homologue of the p53 gene, p63 is considered to be essential for the normal development of stratified epithelium, including epithelium of the urinary tract and prostate. To determine the possible roles of p63 in the male human urogenital tract its expression was systematically examined. MATERIALS AND METHODS Expression of p63 protein was evaluated by immunofluorescence and immunohistochemistry in normal male human urogenital tract tissues. Differential expression of p63 mRNA isoforms was assessed by reverse transcriptase-polymerase chain reaction. RESULTS Basal cells in the stratified epithelium of the urinary and reproductive tracts, including the urothelium, prostate, seminal vesicle, ductus deferens and ductus epididymidis, showed intense nuclear immunostaining for p63. In the urinary tract p63 expression disappeared at the epithelium in the mid portion of renal papillae, at which the stratified structure of the epithelium changed to a monolayer structure. In the reproductive tract p63 expression disappeared at the ductuli efferentes. The stratified epithelium of the reproductive tract also changed at this portion. In the testis weak p63 expression was noted in spermatocytes but not in spermatogonia. At the mRNA level DeltaNp63 was predominant in the urothelium, prostate, seminal vesicle, ductus deferens, and cauda and corpus epididymis, while TAp63 was predominant in testicular tissues. In addition, distribution of the TAp63 isoform was clearly distinguishable from c-kit expression, which is a biochemical marker of spermatogonia. CONCLUSIONS Differential expression of p63 transcripts seems to characterize the developmental origin and differential biological function in the male human urogenital tract.
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Affiliation(s)
- Kazutaka Saito
- Department of Urology, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan.
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Hamer G, Gell K, Kouznetsova A, Novak I, Benavente R, Höög C. Characterization of a novel meiosis-specific protein within the central element of the synaptonemal complex. J Cell Sci 2006; 119:4025-32. [PMID: 16968740 DOI: 10.1242/jcs.03182] [Citation(s) in RCA: 112] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
During the first meiotic prophase, alignment and synapsis of the homologous chromosomes are mediated by the synaptonemal complex. Incorrect assembly of this complex results in cell death, impaired meiotic recombination and formation of aneuploid germ cells. We have identified a novel mouse meiosis-specific protein, TEX12, and shown it to be a component of the central element structure of the synaptonemal complex at synapsed homologous chromosomes. Only two other central element proteins, SYCE1 and SYCE2, have been identified to date and, using several mouse knockout models, we show that these proteins and TEX12 specifically depend on the synaptonemal transverse filament protein SYCP1 for localization to the meiotic chromosomes. Additionally, we show that TEX12 exactly co-localized with SYCE2, having the same, often punctate, localization pattern. SYCE1, on the other hand, co-localized with SYCP1 and these proteins displayed the same more continuous expression pattern. These co-localization studies were confirmed by co-immunoprecipitation experiments that showed that TEX12 specifically co-precipitated with SYCE2. Our results suggest a molecular network within the central elements, in which TEX12 and SYCE2 form a complex that interacts with SYCE1. SYCE1 interacts more directly with SYCP1 and could thus anchor the central element proteins to the transverse filaments.
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Affiliation(s)
- Geert Hamer
- Department of Cell and Molecular Biology, Karolinska Institute, Berzelius väg 35, Stockholm, SE-171 77, Sweden
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34
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Tomasini R, Seux M, Nowak J, Bontemps C, Carrier A, Dagorn JC, Pébusque MJ, Iovanna JL, Dusetti NJ. TP53INP1 is a novel p73 target gene that induces cell cycle arrest and cell death by modulating p73 transcriptional activity. Oncogene 2006; 24:8093-104. [PMID: 16044147 DOI: 10.1038/sj.onc.1208951] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
TP53INP1 is an alternatively spliced gene encoding two nuclear protein isoforms (TP53INP1alpha and TP53INP1beta), whose transcription is activated by p53. When overexpressed, both isoforms induce cell cycle arrest in G1 and enhance p53-mediated apoptosis. TP53INP1s also interact with the p53 gene and regulate p53 transcriptional activity. We report here that TP53INP1 expression is induced during experimental acute pancreatitis in p53-/- mice and in cisplatin-treated p53-/- mouse embryo fibroblasts (MEFs). We demonstrate that ectopic expression of p73, a p53 homologue, leads to TP53INP1 induction in p53-deficient cells. In turn, TP53INP1s alters the transactivation capacity of p73 on several p53-target genes, including TP53INP1 itself, demonstrating a functional association between p73 and TP53INP1s. Also, when overexpressed in p53-deficient cells, TP53INP1s inhibit cell growth and promote cell death as assessed by cell cycle analysis and colony formation assays. Finally, we show that TP53INP1s potentiate the capacity of p73 to inhibit cell growth, that effect being prevented when the p53 mutant R175H is expressed or when p73 expression is blocked by a siRNA. These results suggest that TP53INP1s are functionally associated with p73 to regulate cell cycle progression and apoptosis, independently from p53.
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Affiliation(s)
- Richard Tomasini
- INSERM U624, Stress Cellulaire, IFR 137-Institut de Cancérologie et Immunologie de Marseille, Université de la Méditerranée, Marseille, France
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35
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Petre-Lazar B, Livera G, Moreno SG, Trautmann E, Duquenne C, Hanoux V, Habert R, Coffigny H. The role of p63 in germ cell apoptosis in the developing testis. J Cell Physiol 2006; 210:87-98. [PMID: 16998800 DOI: 10.1002/jcp.20829] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The fetal and neonatal development of male germ cells (gonocytes) is a poorly understood but crucial process for establishing fertility. In rodents, gonocytes go through two phases of proliferation accompanied by apoptosis and separated by a quiescent period during the end of fetal development. P63 is a member of the P53 gene family that yields six isoforms. We detected only the p63 protein and no p53 and p73 in the nucleus of the gonocytes of mouse testes. We report for the first time the ontogeny of each p63 mRNA isoform during testis development. We observed a strong expression of p63gamma mRNA and protein when gonocytes are in the quiescent period. In vitro treatment with retinoic acid prevented gonocytes from entering the quiescent period and was correlated with a reduced production of p63gamma isoform mRNA. We investigated the function of p63 by studying the testicular phenotype of P63-null mice. P63 invalidation slightly, but significantly increased the number of gonocytes counted during the quiescent period. As P63-null animals die at birth we used an original organ culture that mimicked neonatal in vivo development to study further the testicular development. P63 invalidation resulted in a sharply increased number of gonocytes during the culture period due to a decrease in spontaneous apoptosis with no change in proliferation. P63 invalidation also caused abnormal morphologies in the germ cells that were also found in P63(+/-) adult male mice. Thus, p63 appears as an important regulator of germ cell development.
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Affiliation(s)
- Bétrice Petre-Lazar
- CEA, DSV/DRR/SEGG, Laboratoire de Différenciation et de Radiobiologie des Gonades, F-92265 Fontenay-aux-Roses, France
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36
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di Pietro A, Vries EGED, Gietema JA, Spierings DCJ, de Jong S. Testicular germ cell tumours: the paradigm of chemo-sensitive solid tumours. Int J Biochem Cell Biol 2005; 37:2437-56. [PMID: 16099193 DOI: 10.1016/j.biocel.2005.06.014] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2005] [Revised: 06/02/2005] [Accepted: 01/27/2005] [Indexed: 11/16/2022]
Abstract
Testicular germ cell tumours (TGCTs) are the most frequent solid malignant tumour in men 20-40 years of age and the most frequent cause of death from solid tumours in this age group. Up to 50% of the patients suffer from metastatic disease at diagnosis. The majority of metastatic testicular cancer patients, in contrast to most other metastatic solid tumours, can be cured with highly effective cisplatin-based chemotherapy. From a genetic point of view, almost all TGCTs in contrast to solid tumours are characterised by the presence of wild type p53. High p53 expression levels are associated with elevated Mdm2 levels and a loss of p21(Waf1/Cip1) expression suggesting a changed functionality of p53. Expression levels of other proteins involved in the regulation of cell cycle progression indicate a deregulated G1-S phase checkpoint in TGCTs. After cisplatin-induced DNA damage, the increasing levels of p53 lead to the trans-activation of a number of genes but not of p21(Waf1/Cip1), preferentially directing TGCT cells into apoptosis or programmed cell death, both via the mitochondrial and the death receptor apoptosis pathways. The sensitivity of TGCTs to chemotherapeutic drugs may lay in the susceptibility of germ cells to apoptosis. Taken together, this provides TGCT as a tumour type model to investigate and understand the molecular determinants of chemotherapy sensitivity of solid tumours. This review aims to summarise the current knowledge on the biological basis of cisplatin-induced apoptosis and response to chemotherapy in TGCTs.
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Affiliation(s)
- Alessandra di Pietro
- Department of Medical Oncology, Internal Medicine, University of Groningen and University Medical Center Groningen, 9713 GZ Hanzeplein 1, Groningen, The Netherlands
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37
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Sayan AE, Paradisi A, Vojtesek B, Knight RA, Melino G, Candi E. New antibodies recognizing p73: Comparison with commercial antibodies. Biochem Biophys Res Commun 2005; 330:186-93. [PMID: 15781249 DOI: 10.1016/j.bbrc.2005.02.145] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2005] [Indexed: 11/24/2022]
Abstract
p73, unlike p53, is expressed as a number of isomeric forms. Alternative splicing at the 3' end of p73 transcript, together with the usage of a second promoter downstream of exon 3, can generate up to 24 p73 isoforms. Variants lacking the TA domain (DeltaN isoforms) are induced by TAp73 and by p53, and inhibit their transcriptional activity. However, understanding the complex biology of p73 has been handicapped by the lack of high affinity specific antibodies for the different isoforms. Here, we report the characterization, by Western blotting and immunoprecipitation, of three new polyclonal antisera recognizing all p73 isoforms, only DeltaN isoforms or only p73alpha, and which have advantages of affinity and specificity over previously available antibodies.
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Affiliation(s)
- A Emre Sayan
- Medical Research Council, Toxicology Unit, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK
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38
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Craveiro R, Costa S, Pinto D, Salgado L, Carvalho L, Castro C, Bravo I, Lopes C, Silva I, Medeiros R. TP73 alterations in cervical carcinoma. ACTA ACUST UNITED AC 2004; 150:116-21. [PMID: 15066318 DOI: 10.1016/j.cancergencyto.2003.08.020] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2003] [Revised: 08/26/2003] [Accepted: 08/27/2003] [Indexed: 12/27/2022]
Abstract
Infection with human papillomaviruses (HPV) is essential in the carcinogenesis of the uterine cervix. However, a complex interrelation between viral and cellular genes is necessary for cell-cycle control deregulation and development and progression of cervical cancer induction. The TP73 gene is localized in 1p36.3 band, which is often deleted by loss of heterozygosity (LOH) in human cancers. We analyzed the p73 cytosine thymine polymorphism and LOH in this locus by polymerase chain reaction restriction fragment length polymorphism in 134 DNA samples from biopsies of 67 primary untreated invasive cervix tumors and the corresponding peripheral blood. Genotype frequencies of 56.7% for homozygous genotype GC/GC and 43.3% for heterozygous genotype GC/AT were found. The presence of the GC/AT genotype in tumors was associated with lower age at menarche (P=0.039) and high parity (P=0.015). In 20.0% of DNA tumor samples, the AT allele was lost compared with their DNA normal blood pairs. The AT allele was conserved in women with high parity. This was not the case in the group with low parity, with 33.3% of patients showing loss of the AT allele in tumor DNA (P=0.041). These results suggest that TP73 genetic alterations may contribute to the genesis and/or progression of cervical carcinoma in an HPV-infected transformation zone under prolonged exposure to events related to pregnancy.
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Affiliation(s)
- Rogéria Craveiro
- Department of Radiotherapy, Instituto Português de Oncologia, Porto, Rua Dr. Ant. Bernardino Almeida, 4200-072 Porto, Portugal
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39
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Abstract
p63 is a member of the p53 gene family and have structural similarities with p53. p63 encodes for multiple isotypes either with N-terminal transactivation domain (TAp63) or without it (DeltaNp63). In the mammalian testis, it has been shown that p53 plays important roles in the regulation of germ cell apoptosis and meiosis. However, little is known for the physiological function of p63 in the mammalian spermatogenesis. To investigate the potential roles of p63 in the developing mouse testis, we examined the expression pattern of p63 in the mouse testis from birth to adulthood. In addition to the TAp63 mRNA which was continuously expressed in the developing testis, transcripts encoding DeltaNp63 was detected at specific stages of testicular development by RT-PCR, from postnatal day 1 to day 7 and from 3 weeks to 4 weeks after birth. Western blot analysis of whole testis lysates with anti-p63 antibody revealed an approximately 68 kD band throughout development and a less abundant protein at 60 kD in the earlier period of postnatal development. Immunopositive reactions for p63 were observed as early as 10 days after birth and p63 protein was localized to the nuclei of spermatocytes and round spermatids. These findings strongly suggest that p63 might be involved in the regulation of proliferation and differentiation of spermatogenic cells in the developing mouse testis.
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40
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Hamer G, Kal HB, Westphal CH, Ashley T, de Rooij DG. Ataxia telangiectasia mutated expression and activation in the testis. Biol Reprod 2003; 70:1206-12. [PMID: 14681204 DOI: 10.1095/biolreprod.103.024950] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Ionizing radiation (IR) and consequent induction of DNA double-strand breaks (DSBs) causes activation of the protein ataxia telangiectasia mutated (ATM). Normally, ATM is present as inactive dimers; however, in response to DSBs, the ATM dimer partners cross-phosphorylate each other on serine 1981, and kinase active ATM monomers are subsequently released. We have studied the presence of both nonphosphorylated as well as active serine 1981 phosphorylated ATM (pS1981-ATM) in the mouse testis. In the nonirradiated testis, ATM was present in spermatogonia and spermatocytes until stage VII of the cycle of the seminiferous epithelium, whereas pS1981-ATM was found only to be present in the sex body of pachytene spermatocytes. In response to IR, ATM became activated by pS1981 cross-phosphorylation in spermatogonia and Sertoli cells. Despite the occurrence of endogenous programmed DSBs during the first meiotic prophase and the presence of ATM in both spermatogonia and spermatocytes, pS1981 phosphorylated ATM did not appear in spermatocytes after treatment with IR. These results show that spermatogonial ATM and ATM in the spermatocytes are differentially regulated. In the mitotically dividing spermatogonia, ATM is activated by cross-phosphorylation, whereas during meiosis nonphosphorylated ATM or differently phosphorylated ATM is already active. ATM has been shown to be present at the synapsed axes of the meiotic chromosomes, and in the ATM knock-out mice spermatogenesis stops at pachytene stage IV of the seminiferous epithelium, indicating that indeed nonphosphorylated ATM is functional during meiosis. Additionally, ATM is constitutively phosphorylated in the sex body where its continued presence remains an enigma.
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Affiliation(s)
- Geert Hamer
- Department of Endocrinology, Faculty of Biology, Utrecht University, 3584 CH Utrecht, The Netherlands.
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41
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Hamer G, Roepers-Gajadien HL, Gademan IS, Kal HB, De Rooij DG. Intercellular bridges and apoptosis in clones of male germ cells. ACTA ACUST UNITED AC 2003; 26:348-53. [PMID: 14636220 DOI: 10.1111/j.1365-2605.2003.00436.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
When an As spermatogonium divides to form a pair of Apr spermatogonia the two daughter cells stay interconnected by an intercellular bridge. These cytoplasmic bridges form after every subsequent division leading to large clones of interconnected germ cells. Cohorts of spermatogonia maintain synchronous development throughout spermatogenesis, which has been attributed to the presence of these intercellular bridges. To examine whether apoptotic signals are transduced through the intercellular bridges we studied germ cell apoptosis in whole mounts of seminiferous tubules from non-irradiated and irradiated mouse testes, using whole mount seminiferous tubules and confocal microscopy. This allowed us to use TUNEL staining of apoptotic germ cells and at the same time to study these apoptotic germ cells in their topographical context. Our results show that in response to ionizing radiation single spermatogonia within a clone can undergo apoptosis without affecting their neighboring cells. Additionally, also early spermatocytes were shown to undergo apoptosis individually. Both radiation-induced spermatogonial apoptosis and spontaneous apoptosis of spermatocytes are caused by DNA damage of individual cells. Degeneration of healthy spermatogonia because of regulatory signals, however, follows other death inducing mechanisms, which lead to apoptosis of chains of interconnected spermatogonia.
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Affiliation(s)
- Geert Hamer
- Department of Endocrinology, Faculty of Biology, Utrecht University, Utrecht, The Netherlands.
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42
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Ben-Yehoyada M, Ben-Dor I, Shaul Y. c-Abl tyrosine kinase selectively regulates p73 nuclear matrix association. J Biol Chem 2003; 278:34475-82. [PMID: 12824179 DOI: 10.1074/jbc.m301051200] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
p73 is a structural and functional homologue of the p53 tumor-suppressor protein. Like p53, p73 is activated in response to DNA-damaging insults to induce cell cycle arrest or apoptosis. Under these conditions p73 is tyrosine-phosphorylated by c-Abl, a prerequisite modification for p73 to elicit cell death in fibroblasts. In this study we report that in response to ionizing radiation, p73 undergoes nuclear redistribution and becomes associated with the nuclear matrix. This association is c-Abl-dependent because it was not observed in cells that are defective in c-Abl kinase activation. Moreover, STI-571, a specific c-Abl kinase inhibitor, is sufficient to block significantly p73 alpha nuclear matrix association. The observed c-Abl dependence of nuclear matrix association was recapitulated in the heterologous baculovirus system. Under these conditions p73 alpha but not p53 is specifically tyrosine-phosphorylated by c-Abl. Moreover, the phosphorylated p73 alpha is predominantly found in association with the nuclear matrix. Thus, in response to ionizing radiation p73 is modified in a c-Abl-dependent manner and undergoes nuclear redistribution and translocates to associate with the nuclear matrix. Our data describe a novel mechanism of p73 regulation.
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Affiliation(s)
- Merav Ben-Yehoyada
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
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43
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Abstract
Apoptosis of testicular germ cells during fetal development is regulated by both p53-dependent and independent mechanisms. However, its precise mechanisms are largely unknown. A member of p53 gene family, p63, is required for p53-dependent apoptosis and can induce apoptosis in the absence of p53 through the activation of p53-target genes. In this study, we examined the expression pattern of p63 in the mouse testis from embryonic day (E) 13.5 to E18.5 to clarify their possible role in the regulation of germ cell apoptosis. Immunostaining for p63 was found in the nucleus of germ cells at E13.5, and continuously observed until E18.5. The RT-PCR using specific primers for two p63 isotypes, those containing the transactivation domain and others not, showed that both transcripts were expressed in the fetal gonads. Possible roles of p63 in the embryonic testes were discussed.
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Affiliation(s)
- Nobuaki Nakamuta
- First Department of Oral Anatomy, Kyushu Dental College, Manazuru Kokurakita, Kitakyushu, Japan
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Spierings DCJ, de Vries EGE, Vellenga E, de Jong S. The attractive Achilles heel of germ cell tumours: an inherent sensitivity to apoptosis-inducing stimuli. J Pathol 2003; 200:137-48. [PMID: 12754734 DOI: 10.1002/path.1373] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Testicular germ cell tumours (TGCTs) are extremely sensitive to cisplatin-containing chemotherapy. The rapid time course of apoptosis induction after exposure to cisplatin suggests that TGCT cells are primed to undergo programmed cell death as an inherent property of the cell of origin. In fact, apoptosis induction of germ cells in the testis is an important physiological mechanism to control the quality and quantity of the gametes produced. Although p53 protein is highly expressed in the majority of TGCTs, almost no p53 mutations have been detected. Interestingly, p53 overexpression is associated with loss of p21 and gain of mdm2 expression, which might indicate a partial loss in functionality of the p53 regulatory pathway in TGCTs. Besides p21, TGCTs often show low expression of other proteins involved in the regulation of cell cycle progression, such as the retinoblastoma protein and members of the INK4 family. It can be postulated that the deregulated G(1)-S phase checkpoint results in premature entry into the S phase upon DNA damage. In addition to Bcl-2 family members that are involved in the regulation of germ cell apoptosis in the normal testis via the mitochondrial death pathway, the Fas death pathway is also known to regulate apoptosis of germ cells in the testis. Since chemotherapy has been shown to activate the Fas death pathway and TGCTs co-express both Fas and its ligand FasL, TGCT cells might undergo apoptosis upon cisplatin treatment via autocrine or paracrine activation of the Fas system by FasL. The hypothesis suggested here is that the lack of cell cycle arrest following a cisplatin-containing treatment, together with the activation of the Fas death pathway and the mitochondrial death pathway, explains the rapid and efficient apoptosis of TGCT cells. Defining the mechanisms involved in the cisplatin sensitivity of TGCTs will provide tools to increase cisplatin sensitivity in other human tumours with acquired or intrinsic resistance.
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Affiliation(s)
- Diana C J Spierings
- Departments of Medical Oncology and Haematology, University of Groningen, The Netherlands
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Hamer G, Roepers-Gajadien HL, van Duyn-Goedhart A, Gademan IS, Kal HB, van Buul PPW, Ashley T, de Rooij DG. Function of DNA-protein kinase catalytic subunit during the early meiotic prophase without Ku70 and Ku86. Biol Reprod 2003; 68:717-21. [PMID: 12604618 DOI: 10.1095/biolreprod.102.008920] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
All components of the double-stranded DNA break (DSB) repair complex DNA-dependent protein kinase (DNA-PK), including Ku70, Ku86, and DNA-PK catalytic subunit (DNA-PKcs), were found in the radiosensitive spermatogonia. Although p53 induction was unaffected, spermatogonial apoptosis occurred faster in the irradiated DNA-PKcs-deficient scid testis. This finding suggests that spermatogonial DNA-PK functions in DNA damage repair rather than p53 induction. Despite the fact that early spermatocytes lack the Ku proteins, spontaneous apoptosis of these cells occurred in the scid testis. The majority of these apoptotic spermatocytes were found at stage IV of the cycle of the seminiferous epithelium where a meiotic checkpoint has been suggested to exist. Meiotic synapsis and recombination during the early meiotic prophase induce DSBs, which are apparently less accurately repaired in scid spermatocytes that then fail to pass the meiotic checkpoint. The role for DNA-PKcs during the meiotic prophase differs from that in mitotic cells; it is not influenced by ionizing radiation and is independent of the Ku heterodimer.
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Affiliation(s)
- Geert Hamer
- Department of Endocrinology, Faculty of Biology, Utrecht University, 3584 CH Utrecht, The Netherlands.
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Kunugita N, Kakihara H, Kawamoto T, Norimura T. Micronuclei induced by low dose rate irradiation in early spermatids of p53 null and wild mice. JOURNAL OF RADIATION RESEARCH 2002; 43 Suppl:S205-S207. [PMID: 12793759 DOI: 10.1269/jrr.43.s205] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
To obtain evidence of the dose-rate effect on induction of micronuclei in early spermatids, we observed frequencies in wild-type p53(+/+), heterozygous p53(+/-) and null p53(-/-) mice 14 days after gamma rays irradiation at a high (1,020 mGy/min) or a low (1.2 mGy/min) dose-rate. A dose- and dose-rate-related increase in micronuclei was seen in early spermatids with no difference between the different p53 status. These data were found to be best fitted by a linear-quadratic dose-response model at a high dose-rate, and by a linear dose-response model at a low dose-rate. The yields at 1.2 mGy/min were significantly lower than those at 1,020 mGy/min in the same manner, independent of p53 status. Testis weight declined significantly after 3 Gy irradiation, but did not depend on dose-rates. In our other studies, we observed the complete elimination both of malformation in fetuses and CD3- 4+ mutant T-lymphocytes in p53(+/+) mice, but not in p53(-/-) mice after irradiation. This indicates that concerted DNA repair and p53-dependent apoptosis are likely to completely eliminate mutagenic damage from the irradiated tissues at low doses or dose-rates in teratogenesis and lymphocytes. In the germ cell, however, irradiation at 1.2 mGy/min was mutagenic, independent of p53 status.
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Affiliation(s)
- Naoki Kunugita
- Department of Health Information Science, University of Occupational & Environmental Health, Yahatanishi-ku, Kitakyushu 807-8555, Japan.
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