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Sharma P, Kaushal N, Saleth LR, Ghavami S, Dhingra S, Kaur P. Oxidative stress-induced apoptosis and autophagy: Balancing the contrary forces in spermatogenesis. Biochim Biophys Acta Mol Basis Dis 2023; 1869:166742. [PMID: 37146914 DOI: 10.1016/j.bbadis.2023.166742] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 04/18/2023] [Accepted: 04/27/2023] [Indexed: 05/07/2023]
Abstract
Spermatogenesis is a complex process in the testis and is a cornerstone of male infertility. The abundance of unsaturated fatty acid and high cell division rate make male germs cells prone to DNA deterioration. ROS-mediated oxidative stress triggers DNA damage, autophagy, and apoptosis in male germ cells, which are critical causative factors that lead to male infertility. The complex connection and molecular crosstalk between apoptosis and autophagy is seen at multifaceted levels that interconnect the signaling pathways of these two processes. Multilevel interaction between apoptosis and autophagy is a seamless state of survival and death in response to various stressors. Interaction between multiple genes and proteins such as the mTor signaling pathway, Atg12 proteins, and the death adapter proteins, such as Beclin 1, p53, and Bcl-2 family proteins, validates such a link between these two phenomena. Testicular cells being epigenetically different from somatic cells, undergo numerous significant epigenetic transitions, and ROS modulates the epigenetic framework of mature sperm. Epigenetic deregulation of apoptosis and autophagy under oxidative stress conditions can cause sperm cell damage. The current review recapitulates the current role of prevailing stressors that generate oxidative stress leading to the induction of apoptosis and autophagy in the male reproductive system. Considering the pathophysiological consequences of ROS-mediated apoptosis and autophagy, a combinatorial approach, including apoptosis inhibition and autophagy activation, a therapeutic strategy to treat male idiopathic infertility. Understanding the crosslink between apoptosis and autophagy under stress conditions in male germ cells may play an essential role in developing therapeutic strategies to treat infertility.
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Affiliation(s)
- Parul Sharma
- Department of Biotechnology, Thapar Institute of Engineering & Technology, Patiala, Punjab 147004, India
| | - Naveen Kaushal
- Department of Biophysics, Panjab University, Chandigarh 160014, India
| | - Leena Regi Saleth
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, Department of Physiology and Pathophysiology, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba R2H 2A6, Canada
| | - Saeid Ghavami
- Department of Human Anatomy and Cell Science, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada; Research Institute of Hematology and Oncology, Cancer Care Manitoba, Winnipeg, MB R3E 0V9, Canada; Faculty of Medicine in Zabrze, University of Technology in Katowice, Academia of Silesia, 41-800 Zabrze, Poland
| | - Sanjiv Dhingra
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, Department of Physiology and Pathophysiology, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba R2H 2A6, Canada
| | - Parminder Kaur
- Department of Biotechnology, University Institute of Engineering & Technology, Panjab University, Chandigarh 160024, India.
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Wang M, Zeng L, Su P, Ma L, Zhang M, Zhang YZ. Autophagy: a multifaceted player in the fate of sperm. Hum Reprod Update 2021; 28:200-231. [PMID: 34967891 PMCID: PMC8889000 DOI: 10.1093/humupd/dmab043] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 11/11/2021] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Autophagy is an intracellular catabolic process of degrading and recycling proteins and organelles to modulate various physiological and pathological events, including cell differentiation and development. Emerging data indicate that autophagy is closely associated with male reproduction, especially the biosynthetic and catabolic processes of sperm. Throughout the fate of sperm, a series of highly specialized cellular events occur, involving pre-testicular, testicular and post-testicular events. Nonetheless, the most fundamental question of whether autophagy plays a protective or harmful role in male reproduction, especially in sperm, remains unclear. OBJECTIVE AND RATIONALE We summarize the functional roles of autophagy in the pre-testicular (hypothalamic–pituitary–testis (HPG) axis), testicular (spermatocytogenesis, spermatidogenesis, spermiogenesis, spermiation) and post-testicular (sperm maturation and fertilization) processes according to the timeline of sperm fate. Additionally, critical mechanisms of the action and clinical impacts of autophagy on sperm are identified, laying the foundation for the treatment of male infertility. SEARCH METHODS In this narrative review, the PubMed database was used to search peer-reviewed publications for summarizing the functional roles of autophagy in the fate of sperm using the following terms: ‘autophagy’, ‘sperm’, ‘hypothalamic–pituitary–testis axis’, ‘spermatogenesis’, ‘spermatocytogenesis’, ‘spermatidogenesis’, ‘spermiogenesis’, ‘spermiation’, ‘sperm maturation’, ‘fertilization’, ‘capacitation’ and ‘acrosome’ in combination with autophagy-related proteins. We also performed a bibliographic search for the clinical impact of the autophagy process using the keywords of autophagy inhibitors such as ‘bafilomycin A1’, ‘chloroquine’, ‘hydroxychloroquine’, ‘3-Methyl Adenine (3-MA)’, ‘lucanthone’, ‘wortmannin’ and autophagy activators such as ‘rapamycin’, ‘perifosine’, ‘metformin’ in combination with ‘disease’, ‘treatment’, ‘therapy’, ‘male infertility’ and equivalent terms. In addition, reference lists of primary and review articles were reviewed for additional relevant publications. All relevant publications until August 2021 were critically evaluated and discussed on the basis of relevance, quality and timelines. OUTCOMES (i) In pre-testicular processes, autophagy-related genes are involved in the regulation of the HPG axis; and (ii) in testicular processes, mTORC1, the main gate to autophagy, is crucial for spermatogonia stem cell (SCCs) proliferation, differentiation, meiotic progression, inactivation of sex chromosomes and spermiogenesis. During spermatidogenesis, autophagy maintains haploid round spermatid chromatoid body homeostasis for differentiation. During spermiogenesis, autophagy participates in acrosome biogenesis, flagella assembly, head shaping and the removal of cytoplasm from elongating spermatid. After spermatogenesis, through PDLIM1, autophagy orchestrates apical ectoplasmic specialization and basal ectoplasmic specialization to handle cytoskeleton assembly, governing spermatid movement and release during spermiation. In post-testicular processes, there is no direct evidence that autophagy participates in the process of capacitation. However, autophagy modulates the acrosome reaction, paternal mitochondria elimination and clearance of membranous organelles during fertilization. WIDER IMPLICATIONS Deciphering the roles of autophagy in the entire fate of sperm will provide valuable insights into therapies for diseases, especially male infertility.
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Affiliation(s)
- Mei Wang
- Center for Reproductive Medicine, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, P.R. China.,Harvard Reproductive Endocrine Science Center and Reproductive Endocrine Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.,Clinical Medicine Research Center of Prenatal Diagnosis and Birth Health in Hubei Province, Wuhan, Hubei, P.R. China
| | - Ling Zeng
- Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, P.R. China
| | - Ping Su
- Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, P.R. China
| | - Ling Ma
- Center for Reproductive Medicine, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, P.R. China.,Clinical Medicine Research Center of Prenatal Diagnosis and Birth Health in Hubei Province, Wuhan, Hubei, P.R. China
| | - Ming Zhang
- Center for Reproductive Medicine, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, P.R. China.,Clinical Medicine Research Center of Prenatal Diagnosis and Birth Health in Hubei Province, Wuhan, Hubei, P.R. China
| | - Yuan Zhen Zhang
- Center for Reproductive Medicine, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, P.R. China.,Clinical Medicine Research Center of Prenatal Diagnosis and Birth Health in Hubei Province, Wuhan, Hubei, P.R. China
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3
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Yang T, Yang WX. The dynamics and regulation of microfilament during spermatogenesis. Gene 2020; 744:144635. [PMID: 32244053 DOI: 10.1016/j.gene.2020.144635] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 02/28/2020] [Accepted: 03/30/2020] [Indexed: 12/22/2022]
Abstract
Spermatogenesis is a highly complex physiological process which contains spermatogonia proliferation, spermatocyte meiosis and spermatid morphogenesis. In the past decade, actin binding proteins and signaling pathways which are critical for regulating the actin cytoskeleton in testis had been found. In this review, we summarized 5 actin-binding proteins that have been proven to play important roles in the seminiferous epithelium. Lack of them perturbs spermatids polarity and the transport of spermatids. The loss of Arp2/3 complex, Formin1, Eps8, Palladin and Plastin3 cause sperm release failure suggesting their irreplaceable role in spermatogenesis. Actin regulation relies on multiple signal pathways. The PI3K/Akt signaling pathway positively regulate the mTOR pathway to promote actin reorganization in seminiferous epithelium. Conversely, TSC1/TSC2 complex, the upstream of mTOR, is activated by the LKB1/AMPK pathway to inhibit cell proliferation, differentiation and migration. The increasing researches focus on the function of actin binding proteins (ABPs), however, their collaborative regulation of actin patterns and potential regulatory signaling networks remains unclear. We reviewed ABPs that play important roles in mammalian spermatogenesis and signal pathways involved in the regulation of microfilaments. We suggest that more relevant studies should be performed in the future.
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Affiliation(s)
- Tong Yang
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Wan-Xi Yang
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
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Moreira BP, Oliveira PF, Alves MG. Molecular Mechanisms Controlled by mTOR in Male Reproductive System. Int J Mol Sci 2019; 20:ijms20071633. [PMID: 30986927 PMCID: PMC6480367 DOI: 10.3390/ijms20071633] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 03/27/2019] [Accepted: 03/28/2019] [Indexed: 12/21/2022] Open
Abstract
In recent years, the mammalian target of rapamycin (mTOR) has emerged as a master integrator of upstream inputs, such as amino acids, growth factors and insulin availability, energy status and many others. The integration of these signals promotes a response through several downstream effectors that regulate protein synthesis, glucose metabolism and cytoskeleton organization, among others. All these biological processes are essential for male fertility, thus it is not surprising that novel molecular mechanisms controlled by mTOR in the male reproductive tract have been described. Indeed, since the first clinical evidence showed that men taking rapamycin were infertile, several studies have evidenced distinct roles for mTOR in spermatogenesis. However, there is a lack of consensus whether mTOR inhibition, which remains the experimental approach that originates the majority of available data, has a negative or positive impact on male reproductive health. Herein we discuss the latest findings concerning mTOR activity in testes, particularly its role on spermatogonial stem cell (SSC) maintenance and differentiation, as well as in the physiology of Sertoli cells (SCs), responsible for blood–testis barrier maintenance/restructuring and the nutritional support of spermatogenesis. Taken together, these recent advances highlight a crucial role for mTOR in determining the male reproductive potential.
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Affiliation(s)
- Bruno P Moreira
- Department of Microscopy, Laboratory of Cell Biology, Institute of Biomedical Sciences Abel Salazar (ICBAS) and Unit for Multidisciplinary Research in Biomedicine (UMIB), University of Porto, 4050-313 Porto, Portugal.
| | - Pedro F Oliveira
- Department of Microscopy, Laboratory of Cell Biology, Institute of Biomedical Sciences Abel Salazar (ICBAS) and Unit for Multidisciplinary Research in Biomedicine (UMIB), University of Porto, 4050-313 Porto, Portugal.
- i3S-Instituto de Investigação e Inovação em Saúde, University of Porto, 4200-135 Porto, Portugal.
- Department of Genetics, Faculty of Medicine, University of Porto, 4200-450 Porto, Portugal.
| | - Marco G Alves
- Department of Microscopy, Laboratory of Cell Biology, Institute of Biomedical Sciences Abel Salazar (ICBAS) and Unit for Multidisciplinary Research in Biomedicine (UMIB), University of Porto, 4050-313 Porto, Portugal.
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LKB1 as a Tumor Suppressor in Uterine Cancer: Mouse Models and Translational Studies. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 943:211-241. [PMID: 27910069 DOI: 10.1007/978-3-319-43139-0_7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The LKB1 tumor suppressor was identified in 1998 as the gene mutated in the Peutz-Jeghers Syndrome (PJS), a hereditary cancer predisposition characterized by gastrointestinal polyposis and a high incidence of cancers, particularly carcinomas, at a variety of anatomic sites including the gastrointestinal tract, lung, and female reproductive tract. Women with PJS have a high incidence of carcinomas of the uterine corpus (endometrium) and cervix. The LKB1 gene is also somatically mutated in human cancers arising at these sites. Work in mouse models has highlighted the potency of LKB1 as an endometrial tumor suppressor and its distinctive roles in driving invasive and metastatic growth. These in vivo models represent tractable experimental systems for the discovery of underlying biological principles and molecular processes regulated by LKB1 in the context of tumorigenesis and also serve as useful preclinical model systems for experimental therapeutics. Here we review LKB1's known roles in mTOR signaling, metabolism, and cell polarity, with an emphasis on human pathology and mouse models relevant to uterine carcinogenesis, including cancers of the uterine corpus and cervix.
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Jesus TT, Oliveira PF, Sousa M, Cheng CY, Alves MG. Mammalian target of rapamycin (mTOR): a central regulator of male fertility? Crit Rev Biochem Mol Biol 2017; 52:235-253. [PMID: 28124577 DOI: 10.1080/10409238.2017.1279120] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Mammalian target of rapamycin (mTOR) is a central regulator of cellular metabolic phenotype and is involved in virtually all aspects of cellular function. It integrates not only nutrient and energy-sensing pathways but also actin cytoskeleton organization, in response to environmental cues including growth factors and cellular energy levels. These events are pivotal for spermatogenesis and determine the reproductive potential of males. Yet, the molecular mechanisms by which mTOR signaling acts in male reproductive system remain a matter of debate. Here, we review the current knowledge on physiological and molecular events mediated by mTOR in testis and testicular cells. In recent years, mTOR inhibition has been explored as a prime strategy to develop novel therapeutic approaches to treat cancer, cardiovascular disease, autoimmunity, and metabolic disorders. However, the physiological consequences of mTOR dysregulation and inhibition to male reproductive potential are still not fully understood. Compelling evidence suggests that mTOR is an arising regulator of male fertility and better understanding of this atypical protein kinase coordinated action in testis will provide insightful information concerning its biological significance in other tissues/organs. We also discuss why a new generation of mTOR inhibitors aiming to be used in clinical practice may also need to include an integrative view on the effects in male reproductive system.
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Affiliation(s)
- Tito T Jesus
- a Laboratory of Cell Biology, Department of Microscopy and Unit for Multidisciplinary Research in Biomedicine (UMIB), Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto , Porto , Portugal.,b CICS-UBI - Health Sciences Research Centre, University of Beira Interior , Covilhã , Portugal
| | - Pedro F Oliveira
- a Laboratory of Cell Biology, Department of Microscopy and Unit for Multidisciplinary Research in Biomedicine (UMIB), Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto , Porto , Portugal.,c i3S - Instituto de Investigação e Inovação em Saúde, University of Porto , Porto , Portugal
| | - Mário Sousa
- a Laboratory of Cell Biology, Department of Microscopy and Unit for Multidisciplinary Research in Biomedicine (UMIB), Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto , Porto , Portugal.,d Centre for Reproductive Genetics Prof. Alberto Barros , Porto , Portugal
| | - C Yan Cheng
- e The Mary M. Wohlford Laboratory for Male Contraceptive Research , Center for Biomedical Research, Population Council , New York , NY , USA
| | - Marco G Alves
- a Laboratory of Cell Biology, Department of Microscopy and Unit for Multidisciplinary Research in Biomedicine (UMIB), Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto , Porto , Portugal.,b CICS-UBI - Health Sciences Research Centre, University of Beira Interior , Covilhã , Portugal
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7
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Array-CGH diagnosis in ovarian failure: identification of new molecular actors for ovarian physiology. J Ovarian Res 2016; 9:63. [PMID: 27716277 PMCID: PMC5048446 DOI: 10.1186/s13048-016-0272-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 09/23/2016] [Indexed: 11/13/2022] Open
Abstract
Background Ovarian failure (OF) is considered premature if it occurs before the age of 40. This study investigates the genetic aetiology underlying OF in women under the age of 40 years. Methods We conducted an experimental prospective study performing all genome microarrays in 60 patients younger than 40 years presenting an OF revealed by a decrease of circulating Anti-Müllerian Hormone (AMH) and leading to an oocyte donation program. Results We identified nine significant copy number variations (CNVs) including candidate genes potentially implicated in reproductive function. These genes are principally involved in cell division and chromosome segregation (SYCE1, CLASP1, CENP-A, CDC16), in ciliary development and/or function (RSPH1, KIF24), are linked with known gonadal genes or expressed in female genital tract (CSMD1, SEMA6D, KIAA1324). Conclusions Our data strengthen the idea that microarrays should be used in combination with karyotype for aetiological assessment of patients with OF. This analysis may have a therapeutic impact as the identification of new molecular actors for gonadal development or ovarian physiology is useful for the prediction of an ovarian reserve decline and makes possible preventive fertility preservation.
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8
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Spermatogenic Cell-Specific Gene Mutation in Mice via CRISPR-Cas9. J Genet Genomics 2016; 43:289-96. [PMID: 27210043 DOI: 10.1016/j.jgg.2016.02.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 02/02/2016] [Accepted: 02/15/2016] [Indexed: 12/30/2022]
Abstract
Tissue-specific knockout technology enables the analysis of the gene function in specific tissues in adult mammals. However, conventional strategy for producing tissue-specific knockout mice is a time- and labor-consuming process, restricting rapid study of the gene function in vivo. CRISPR-Cas9 system from bacteria is a simple and efficient gene-editing technique, which has enabled rapid generation of gene knockout lines in mouse by direct injection of CRISPR-Cas9 into zygotes. Here, we demonstrate CRISPR-Cas9-mediated spermatogenic cell-specific disruption of Scp3 gene in testes in one step. We first generated transgenic mice by pronuclear injection of a plasmid containing Hspa2 promoter driving Cas9 expression and showed Cas9 specific expression in spermatogenic cells. We then produced transgenic mice carrying Hspa2 promoter driven Cas9 and constitutive expressed sgRNA targeting Scp3 gene. Male founders were infertile due to developmental arrest of spermatogenic cells while female founders could produce progeny normally. Consistently, male progeny from female founders were infertile and females could transmit the transgenes to the next generation. Our study establishes a CRISPR-Cas9-based one-step strategy to analyze the gene function in adult tissues by a temporal-spatial pattern.
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9
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Ottesen EW, Howell MD, Singh NN, Seo J, Whitley EM, Singh RN. Severe impairment of male reproductive organ development in a low SMN expressing mouse model of spinal muscular atrophy. Sci Rep 2016; 6:20193. [PMID: 26830971 PMCID: PMC4735745 DOI: 10.1038/srep20193] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 12/23/2015] [Indexed: 12/21/2022] Open
Abstract
Spinal muscular atrophy (SMA) is caused by low levels of survival motor neuron (SMN), a multifunctional protein essential for higher eukaryotes. While SMN is one of the most scrutinized proteins associated with neurodegeneration, its gender-specific role in vertebrates remains unknown. We utilized a mild SMA model (C/C model) to examine the impact of low SMN on growth and development of mammalian sex organs. We show impaired testis development, degenerated seminiferous tubules, reduced sperm count and low fertility in C/C males, but no overt sex organ phenotype in C/C females. Underscoring an increased requirement for SMN expression, wild type testis showed extremely high levels of SMN protein compared to other tissues. Our results revealed severe perturbations in pathways critical to C/C male reproductive organ development and function, including steroid biosynthesis, apoptosis, and spermatogenesis. Consistent with enhanced apoptosis in seminiferous tubules of C/C testes, we recorded a drastic increase in cells with DNA fragmentation. SMN was expressed at high levels in adult C/C testis due to an adult-specific splicing switch, but could not compensate for low levels during early testicular development. Our findings uncover novel hallmarks of SMA disease progression and link SMN to general male infertility.
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Affiliation(s)
- Eric W Ottesen
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa 50011, USA
| | - Matthew D Howell
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa 50011, USA
| | - Natalia N Singh
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa 50011, USA
| | - Joonbae Seo
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa 50011, USA
| | - Elizabeth M Whitley
- Department of Veterinary Pathology, Iowa State University, Ames, Iowa 50011, USA
| | - Ravindra N Singh
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa 50011, USA
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Arriola Apelo SI, Neuman JC, Baar EL, Syed FA, Cummings NE, Brar HK, Pumper CP, Kimple ME, Lamming DW. Alternative rapamycin treatment regimens mitigate the impact of rapamycin on glucose homeostasis and the immune system. Aging Cell 2016; 15:28-38. [PMID: 26463117 PMCID: PMC4717280 DOI: 10.1111/acel.12405] [Citation(s) in RCA: 125] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/25/2015] [Indexed: 12/23/2022] Open
Abstract
Inhibition of the mechanistic target of rapamycin (mTOR) signaling pathway by the FDA-approved drug rapamycin has been shown to promote lifespan and delay age-related diseases in model organisms including mice. Unfortunately, rapamycin has potentially serious side effects in humans, including glucose intolerance and immunosuppression, which may preclude the long-term prophylactic use of rapamycin as a therapy for age-related diseases. While the beneficial effects of rapamycin are largely mediated by the inhibition of mTOR complex 1 (mTORC1), which is acutely sensitive to rapamycin, many of the negative side effects are mediated by the inhibition of a second mTOR-containing complex, mTORC2, which is much less sensitive to rapamycin. We hypothesized that different rapamycin dosing schedules or the use of FDA-approved rapamycin analogs with different pharmacokinetics might expand the therapeutic window of rapamycin by more specifically targeting mTORC1. Here, we identified an intermittent rapamycin dosing schedule with minimal effects on glucose tolerance, and we find that this schedule has a reduced impact on pyruvate tolerance, fasting glucose and insulin levels, beta cell function, and the immune system compared to daily rapamycin treatment. Further, we find that the FDA-approved rapamycin analogs everolimus and temsirolimus efficiently inhibit mTORC1 while having a reduced impact on glucose and pyruvate tolerance. Our results suggest that many of the negative side effects of rapamycin treatment can be mitigated through intermittent dosing or the use of rapamycin analogs.
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Affiliation(s)
- Sebastian I. Arriola Apelo
- Department of Medicine University of Wisconsin‐Madison Madison WI USA
- William S. Middleton Memorial Veterans Hospital Madison WI USA
| | - Joshua C. Neuman
- William S. Middleton Memorial Veterans Hospital Madison WI USA
- Interdisciplinary Graduate Program in Nutritional Sciences University of Wisconsin‐Madison Madison WI USA
| | - Emma L. Baar
- Department of Medicine University of Wisconsin‐Madison Madison WI USA
- William S. Middleton Memorial Veterans Hospital Madison WI USA
| | - Faizan A. Syed
- Department of Medicine University of Wisconsin‐Madison Madison WI USA
- William S. Middleton Memorial Veterans Hospital Madison WI USA
| | - Nicole E. Cummings
- Department of Medicine University of Wisconsin‐Madison Madison WI USA
- William S. Middleton Memorial Veterans Hospital Madison WI USA
- Endocrinology and Reproductive Physiology Graduate Training Program University of Wisconsin‐Madison Madison WI USA
| | - Harpreet K. Brar
- Department of Medicine University of Wisconsin‐Madison Madison WI USA
- William S. Middleton Memorial Veterans Hospital Madison WI USA
| | - Cassidy P. Pumper
- Department of Medicine University of Wisconsin‐Madison Madison WI USA
- William S. Middleton Memorial Veterans Hospital Madison WI USA
| | - Michelle E. Kimple
- Department of Medicine University of Wisconsin‐Madison Madison WI USA
- William S. Middleton Memorial Veterans Hospital Madison WI USA
- Interdisciplinary Graduate Program in Nutritional Sciences University of Wisconsin‐Madison Madison WI USA
- Endocrinology and Reproductive Physiology Graduate Training Program University of Wisconsin‐Madison Madison WI USA
| | - Dudley W. Lamming
- Department of Medicine University of Wisconsin‐Madison Madison WI USA
- William S. Middleton Memorial Veterans Hospital Madison WI USA
- Interdisciplinary Graduate Program in Nutritional Sciences University of Wisconsin‐Madison Madison WI USA
- Endocrinology and Reproductive Physiology Graduate Training Program University of Wisconsin‐Madison Madison WI USA
- University of Wisconsin Carbone Cancer Center Madison WI USA
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Tian Q, Smart JL, Clement JH, Wang Y, Derkatch A, Schubert H, Danilchik MV, Marks DL, Fedorov LM. RHEB1 expression in embryonic and postnatal mouse. Histochem Cell Biol 2015; 145:561-72. [PMID: 26708151 DOI: 10.1007/s00418-015-1394-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/08/2015] [Indexed: 12/16/2022]
Abstract
Ras homolog enriched in brain (RHEB1) is a member within the superfamily of GTP-binding proteins encoded by the RAS oncogenes. RHEB1 is located at the crossroad of several important pathways including the insulin-signaling pathways and thus plays an important role in different physiological processes. To understand better the physiological relevance of RHEB1 protein, the expression pattern of RHEB1 was analyzed in both embryonic (at E3.5-E16.5) and adult (1-month old) mice. RHEB1 immunostaining and X-gal staining were used for wild-type and Rheb1 gene trap mutant mice, respectively. These independent methods revealed similar RHEB1 expression patterns during both embryonic and postnatal developments. Ubiquitous uniform RHEB1/β-gal and/or RHEB1 expression was seen in preimplantation embryos at E3.5 and postimplantation embryos up to E12.5. Between stages E13.5 and E16.5, RHEB1 expression levels became complex: In particular, strong expression was identified in neural tissues, including the neuroepithelial layer of the mesencephalon, telencephalon, and neural tube of CNS and dorsal root ganglia. In addition, strong expression was seen in certain peripheral tissues including heart, intestine, muscle, and urinary bladder. Postnatal mice have broad spatial RHEB1 expression in different regions of the cerebral cortex, subcortical regions (including hippocampus), olfactory bulb, medulla oblongata, and cerebellum (particularly in Purkinje cells). Significant RHEB1 expression was also viewed in internal organs including the heart, intestine, urinary bladder, and muscle. Moreover, adult animals have complex tissue- and organ-specific RHEB1 expression patterns with different intensities observed throughout postnatal development. Its expression level is in general comparable in CNS and other organs of mouse. Thus, the expression pattern of RHEB1 suggests that it likely plays a ubiquitous role in the development of the early embryo with more tissue-specific roles in later development.
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Affiliation(s)
- Qi Tian
- OHSU Transgenic Mouse Models Shared Resource, Knight Cancer Institute, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA
| | | | - Joachim H Clement
- Department of Hematology and Oncology, Jena University Hospital, 07747, Jena, Germany
| | - Yingming Wang
- OHSU Transgenic Mouse Models Shared Resource, Knight Cancer Institute, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA
| | - Alex Derkatch
- OHSU Transgenic Mouse Models Shared Resource, Knight Cancer Institute, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA
| | | | - Michael V Danilchik
- Department of Integrative Biosciences, Oregon Health and Science University, Portland, OR, USA
| | - Daniel L Marks
- Department of Pediatrics, Oregon Health and Science University, Portland, OR, USA
| | - Lev M Fedorov
- OHSU Transgenic Mouse Models Shared Resource, Knight Cancer Institute, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA.
- Friedrich-Schiller-University, 07740, Jena, Germany.
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Ezzati MM, Baker MD, Saatcioglu HD, Aloisio GM, Pena CG, Nakada Y, Cuevas I, Carr BR, Castrillon DH. Regulation of FOXO3 subcellular localization by Kit ligand in the neonatal mouse ovary. J Assist Reprod Genet 2015; 32:1741-7. [PMID: 26507072 DOI: 10.1007/s10815-015-0589-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 09/28/2015] [Indexed: 11/25/2022] Open
Abstract
PURPOSE Foxo3 protein is required in the oocyte nucleus for the maintenance of primordial follicles in a dormant state. PI3K/AKT-dependent phosphorylation of Foxo3 leads to its relocalization to the cytoplasm and subsequent follicular activation. However, the nature of the upstream signals controlling Foxo3 activity and subcellular localization remains unknown. We aimed to study the in vitro effects of Kit ligand (stem cell factor) on the subcellular localization of Foxo3 in primordial follicles within the postnatal mouse ovary. METHODS This was an in vitro study using explants of intact neonatal mouse ovaries. The study was performed in laboratory animal facility and basic science research laboratory at a University Hospital. The animals used for this study were FVB mice. Neonatal FVB mice ovaries at postnatal day 7 (PD7) were harvested and incubated in culture medium (DMEM) at 37 °C and 5 % CO(2) for 60-90 min with (n = 3) or without (n = 3) Kit ligand at 150 ng/mL (8 nM). Similar experimental conditions were used to establish a dose-response curve for the effects of Kit ligand and assess the effects of imatinib (small molecule inhibitor of the Kit receptor). Immunofluorescence was used to identify the subcellular location of Foxo3 in oocytes. Proportions of cytoplasmic versus nuclear Foxo3 in primordial follicles were determined. RESULTS Kit ligand treatment increased the cytoplasmic localization of Foxo3 from 40 % in the untreated ovaries to 74 % in the treated group (p = 0.007 in paired samples and p = 0.03 in unpaired samples). Furthermore, this effect was reversible with imatinib (p = 0.005). A dose-response curve for Kit ligand treatment showed that maximum effect was seen at 150 ng/mL. CONCLUSION Kit ligand treatment in vitro increases the proportion of cytoplasmic Foxo3 in primordial follicles at PD7, lending support to the idea that Kit receptor/ligand controls Foxo3 activity in the context of primordial follicle activation.
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Affiliation(s)
- M Max Ezzati
- Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, 6000 Harry Hines Blvd, Dallas, TX, 75390-9072, USA.
- Palo Alto Medical Foundation, Palo Alto, CA, USA.
| | - Michael D Baker
- Department of Pathology, University of Texas Southwestern Medical Center, 6000 Harry Hines Blvd, Dallas, TX, 75390-9072, USA
| | - Hatice D Saatcioglu
- Department of Pathology, University of Texas Southwestern Medical Center, 6000 Harry Hines Blvd, Dallas, TX, 75390-9072, USA
| | - Gina M Aloisio
- Department of Pathology, University of Texas Southwestern Medical Center, 6000 Harry Hines Blvd, Dallas, TX, 75390-9072, USA
| | - Christopher G Pena
- Department of Pathology, University of Texas Southwestern Medical Center, 6000 Harry Hines Blvd, Dallas, TX, 75390-9072, USA
| | - Yuji Nakada
- Department of Pathology, University of Texas Southwestern Medical Center, 6000 Harry Hines Blvd, Dallas, TX, 75390-9072, USA
| | - Ileana Cuevas
- Department of Pathology, University of Texas Southwestern Medical Center, 6000 Harry Hines Blvd, Dallas, TX, 75390-9072, USA
| | - Bruce R Carr
- Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, 6000 Harry Hines Blvd, Dallas, TX, 75390-9072, USA
| | - Diego H Castrillon
- Department of Pathology, University of Texas Southwestern Medical Center, 6000 Harry Hines Blvd, Dallas, TX, 75390-9072, USA.
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Recent progress in the study of the Rheb family GTPases. Cell Signal 2014; 26:1950-7. [PMID: 24863881 DOI: 10.1016/j.cellsig.2014.05.011] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Accepted: 05/15/2014] [Indexed: 11/20/2022]
Abstract
In this review we highlight recent progress in the study of Rheb family GTPases. Structural studies using X-ray crystallography and NMR have given us insight into unique features of this GTPase. Combined with mutagenesis studies, these works have expanded our understanding of residues that affect Rheb GTP/GDP bound ratios, effector protein interactions, and stimulation of mTORC1 signaling. Analysis of cancer genome databases has revealed that several human carcinomas contain activating mutations of the protein. Rheb's role in activating mTORC1 signaling at the lysosome in response to stimuli has been further elucidated. Rheb has also been suggested to play roles in other cellular pathways including mitophagy and peroxisomal ROS response. A number of studies in mice have demonstrated the importance of Rheb in development, as well as in a variety of functions including cardiac protection and myelination. We conclude with a discussion of future prospects in the study of Rheb family GTPases.
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