1
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Chen L, Qiao L, Guo Y, Huang Y, Luo W, Feng Y. Localization and regulatory function of Yin Yang 1 (YY1) in chicken testis. Mol Genet Genomics 2021; 297:113-123. [PMID: 34854981 DOI: 10.1007/s00438-021-01840-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 11/17/2021] [Indexed: 11/25/2022]
Abstract
In mammals, Yin Yang 1 (YY1), a pervasively expressed transcription factor related to many biological processes as an activator or inhibitor of the transcription of various genes, plays a critical role in the development of male gonads and spermatogenesis. Although the role of YY1 on the development of male gonads and spermatogenesis in mammals has been reported, its function on chicken testis are yet to be clarified. In this study, we used immunofluorescence analysis to investigate the location of YY1 in chicken testis. In embryo testis, YY1 was detected in spermatogonia and Sertoli cells, while in adult testis, YY1 was shown to be expressed in spermatogenic cells and Sertoli cells, but not in spermatozoa. Furthermore, we investigated the regulatory functions of YY1 in chicken testicular Sertoli cells by combining overexpression with RNA-sequencing. Overexpression of YY1 in Sertoli cells revealed a total of 2955 differentially expressed genes involved in various biological processes, such as male gonad development and seminiferous tubule development. Overexpression of YY1 also caused significant differences in the expression of the androgen receptor gene and the inhibin βA gene, two major genes involved in the regulation of spermatogonia in Sertoli cells. These observations indicate that YY1 may regulate the development and function of the gonads by affecting the secretion of cytokines and hormones in Sertoli cells to mediate the production and differentiation of spermatogonia.
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Affiliation(s)
- Ligen Chen
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Animal Science and Technology and College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Lingyun Qiao
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Animal Science and Technology and College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Yan Guo
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Animal Science and Technology and College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Ying Huang
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Animal Science and Technology and College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Wei Luo
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Animal Science and Technology and College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Yanping Feng
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Animal Science and Technology and College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China.
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2
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Affiliation(s)
- Mehwish Saba Aslam
- Department of Microbiology and Immunology, School of Medicine, Southeast University, Nanjing, China
| | - Liudi Yuan
- Department of Microbiology and Immunology, School of Medicine, Southeast University, Nanjing, China
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3
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Gupta GS. P-Type Lectins: Cation-Dependent Mannose-6-Phosphate Receptor. ANIMAL LECTINS: FORM, FUNCTION AND CLINICAL APPLICATIONS 2012. [PMCID: PMC7121444 DOI: 10.1007/978-3-7091-1065-2_3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
In eukaryotic cells, post-translational modification of secreted proteins and intracellular protein transport between organelles are ubiquitous features. One of the most studied systems is the N-linked glycosylation pathway in the synthesis of secreted glycoproteins (Schrag et al. 2003). The N-linked glycoproteins are subjected to diverse modifications and are transported through ER and Golgi apparatus to their final destinations in- and outside the cell. Incorporation of cargo glycoproteins into transport vesicles is mediated by transmembrane cargo receptors, which have been identified as intracellular lectins. For example, mannose 6-phosphate receptors (Ghosh et al. 2003) function as a cargo receptor for lysosomal proteins in the trans-Golgi network, whereas ERGIC-53 (Zhang et al. 2003) and its yeast orthologs Emp46/47p (Sato and Nakano 2002) are transport lectins for glycoproteins that are transported out of ER.
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Affiliation(s)
- G. S. Gupta
- Department of Biophysics, Punjab University, Chandigarh, India
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4
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El‐Shewy HM, Luttrell LM. Chapter 24 Insulin‐Like Growth Factor‐2/Mannose‐6 Phosphate Receptors. VITAMINS & HORMONES 2009; 80:667-97. [DOI: 10.1016/s0083-6729(08)00624-9] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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5
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Hawkes C, Amritraj A, Macdonald RG, Jhamandas JH, Kar S. Heterotrimeric G proteins and the single-transmembrane domain IGF-II/M6P receptor: functional interaction and relevance to cell signaling. Mol Neurobiol 2008; 35:329-45. [PMID: 17917122 DOI: 10.1007/s12035-007-0021-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2007] [Revised: 11/30/1999] [Accepted: 04/02/2007] [Indexed: 12/11/2022]
Abstract
The G protein-coupled receptor (GPCR) family represents the largest and most versatile group of cell surface receptors. Classical GPCR signaling constitutes ligand binding to a seven-transmembrane domain receptor, receptor interaction with a heterotrimeric G protein, and the subsequent activation or inhibition of downstream intracellular effectors to mediate a cellular response. However, recent reports on direct, receptor-independent G protein activation, G protein-independent signaling by GPCRs, and signaling of nonheptahelical receptors via trimeric G proteins have highlighted the intrinsic complexities of G protein signaling mechanisms. The insulin-like growth factor-II/mannose-6 phosphate (IGF-II/M6P) receptor is a single-transmembrane glycoprotein whose principal function is the intracellular transport of lysosomal enzymes. In addition, the receptor also mediates some biological effects in response to IGF-II binding in both neuronal and nonneuronal systems. Multidisciplinary efforts to elucidate the intracellular signaling pathways that underlie these effects have generated data to suggest that the IGF-II/M6P receptor might mediate transmembrane signaling via a G protein-coupled mechanism. The purpose of this review is to outline the characteristics of traditional and nontraditional GPCRs, to relate the IGF-II/M6P receptor's structure with its role in G protein-coupled signaling and to summarize evidence gathered over the years regarding the putative signaling of the IGF-II/M6P receptor mediated by a G protein.
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Affiliation(s)
- C Hawkes
- Department of Psychiatry, Centre for Alzheimer and Neurodegenerative Research, University of Alberta, Edmonton, AB, T6G 2B7, Canada
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6
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Vemuganti SA, Bell TA, Scarlett CO, Parker CE, de Villena FPM, O'Brien DA. Three male germline-specific aldolase A isozymes are generated by alternative splicing and retrotransposition. Dev Biol 2007; 309:18-31. [PMID: 17659271 DOI: 10.1016/j.ydbio.2007.06.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2007] [Revised: 06/09/2007] [Accepted: 06/12/2007] [Indexed: 10/23/2022]
Abstract
Enzymes in the glycolytic pathway of mammalian sperm are modified extensively and are localized in the flagellum, where several are tightly bound to the fibrous sheath. This study provides the first evidence for three novel aldolase isozymes in mouse sperm, two encoded by Aldoart1 and Aldoart2 retrogenes on different chromosomes and another by Aldoa_v2, a splice variant of Aldoa. Phylogenetic analyses and comparative genomics indicate that the retrogenes and splice variant have remained functional and have been under positive selection for millions of years. Their expression is restricted to the male germline and is tightly regulated at both transcriptional and translational levels. All three isozymes are present only in spermatids and sperm and have distinctive features that may be important for localization in the flagellum and/or altered metabolic regulation. Both ALDOART1 and ALDOA_V2 have unusual N-terminal extensions not found in other aldolases. The N-terminal extension of ALDOA_V2 is highly conserved in mammals, suggesting a conserved function in sperm. We hypothesize that the N-terminal extensions are responsible for localizing components of the glycolytic pathway to the fibrous sheath and that this localization is required to provide sufficient ATP along the length of the flagellum to support sperm motility.
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Affiliation(s)
- Soumya A Vemuganti
- Laboratories for Reproductive Biology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
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7
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Sipione S, Simmen KC, Lord SJ, Motyka B, Ewen C, Shostak I, Rayat GR, Dufour JM, Korbutt GS, Rajotte RV, Bleackley RC. Identification of a Novel Human Granzyme B Inhibitor Secreted by Cultured Sertoli Cells. THE JOURNAL OF IMMUNOLOGY 2006; 177:5051-8. [PMID: 17015688 DOI: 10.4049/jimmunol.177.8.5051] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Sertoli cells have long since been recognized for their ability to suppress the immune system and protect themselves as well as other cell types from harmful immune reaction. However, the exact mechanism or product produced by Sertoli cells that affords this immunoprotection has never been fully elucidated. We examined the effect of mouse Sertoli cell-conditioned medium on human granzyme B-mediated killing and found that there was an inhibitory effect. We subsequently found that a factor secreted by Sertoli cells inhibited killing through the inhibition of granzyme B enzymatic activity. SDS-PAGE analysis revealed that this factor formed an SDS-insoluble complex with granzyme B. Immunoprecipitation and mass spectroscopic analysis of the complex identified a proteinase inhibitor, serpina3n, as a novel inhibitor of human granzyme B. We cloned serpina3n cDNA, expressed it in Jurkat cells, and confirmed its inhibitory action on granzyme B activity. Our studies have led to the discovery of a new inhibitor of granzyme B and have uncovered a new mechanism used by Sertoli cells for immunoprotection.
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Affiliation(s)
- Simonetta Sipione
- Department of Surgery, University of Alberta, Edmonton, Alberta, Canada
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8
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Abd-Elmaksoud A, Abo-Elmaksoud A, Sinowatz F. Expression and localization of growth factors and their receptors in the mammalian testis. Part I: Fibroblast growth factors and insulin-like growth factors. Anat Histol Embryol 2005; 34:319-34. [PMID: 16159374 DOI: 10.1111/j.1439-0264.2005.00651.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
It is now well established that normal development and function of testis are mediated by endocrine and paracrine pathways including hormones, growth factors and cytokines as well as by direct cell-to-cell contacts depending on tight, adhering and gap junctions. In the last two decades, several growth factors were identified in the testis of various mammalian species. Growth factors are shown to promote cell proliferation, regulate tissue differentiation, and modulate organogenesis. Interestingly, most of these peptides are expressed not only in the adult mammalian testis during spermatogenesis but also during testicular morphogenesis in prenatal and postnatal life. Our study was launched to provide an overview of the expression, localization, and putative physiological roles of growth factors and their receptors in the mammalian testis. The growth factors considered in this part of our review are fibroblast growth factors and insulin-like growth factors. These factors are found in testicular cells in prenatal, postnatal, and adult animals and are implicated in the regulation of important testicular activities including testicular cord morphogenesis, modulation of testicular hormone secretion and control of spermatogenesis.
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Affiliation(s)
- A Abd-Elmaksoud
- Institute of Veterinary Anatomy II, University of Munich, Veterinärstrasse 13, D-80539 Munich, Germany
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9
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Ing NH, Laughlin AM, Varner DD, Welsh TH, Forrest DW, Blanchard TL, Johnson L. Gene expression in the spermatogenically inactive "dark" and maturing "light" testicular tissues of the prepubertal colt. ACTA ACUST UNITED AC 2005; 25:535-44. [PMID: 15223842 DOI: 10.1002/j.1939-4640.2004.tb02824.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
In the testis of the 1.5-year-old horse, spermatogenesis initiates locally in grossly light, central areas that contrast with grossly dark, peripheral areas that are as yet inactive in spermatogenesis. Gene expression was compared between "light" and "dark" tissues of 1.5-year-old horse testes to identify mechanisms important to the initiation of spermatogenesis. Microarrays containing human cDNAs were used to assess expression levels of 9132 genes simultaneously in matched pairs of dark and light testis tissues from 3 prepubertal colts. In all 3 analyses, dysferlin (DYS), down-regulated in ovarian cancer 1 (DOC1), and Golgi apparatus protein 1 (GLG1) genes were preferentially expressed in dark tissues, while outer dense fiber of sperm tails (ODF2) and phosphodiesterase 3B (PDE3B) genes were more highly expressed in light testis tissue (>1.7 balanced difference value, Incyte GEM tools software). Expression levels of 88 additional genes appeared to be different between dark and light tissues in 2 of the 3 microarray analyses. The preferential expression of DYS, DOC1, ODF2, and PDE3B genes in dark or light testis tissues was confirmed on Northern blots and localized to cell types by in situ hybridization. Future studies to determine the role of genes regulated during the initiation of spermatogenesis may aid in elucidating molecular mechanisms during this critical time as well as in identifying new therapies for enhancing male fertility.
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Affiliation(s)
- Nancy H Ing
- Department of Animal Science, Texas A&M University, College Station, 77843, USA.
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10
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Pantaleon M, Jericho H, Rabnott G, Kaye PL. The role of insulin-like growth factor II and its receptor in mouse preimplantation development. Reprod Fertil Dev 2005; 15:37-45. [PMID: 12729502 DOI: 10.1071/rd02031] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2002] [Accepted: 12/16/2002] [Indexed: 12/25/2022] Open
Abstract
Insulin-like growth factor II (IGF-II) and its receptor, the IGF-II/mannose-6-phosphate (IGF-II/M6P) receptor, are first expressed from the zygotic genome at the two-cell stage of mouse development. However, their role is not clearly defined. Insulin-like growth factor II is believed to mediate growth through the heterologous type 1 IGF and insulin receptors, whereas the IGF-II/M6P receptor is believed to act as a negative regulator of somatic growth by limiting the availability of excess levels of IGF-II. These studies demonstrate that IGF-II does have a role in growth regulation in the early embryo through the IGF-II/M6P receptor. Insulin-like growth factor II stimulated cleavage rate in two-cell embryos in vitro. Moreover, this receptor is required for the glycaemic response of two-cell embryos to IGF-II and for normal progression of early embryos to the blastocyst stage. Improved development of embryos in crowded culture supports the concept of an endogenous embryonic paracrine activity that enhances cell proliferation. These responses indicate that the IGF-II/M6P receptor is functional and likely to participate in such a regulatory circuit. The functional role of IGF-II and its receptor is discussed with reference to regulation of early development.
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Affiliation(s)
- M Pantaleon
- Department of Physiology and Pharmacology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia
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11
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Grimes SR. Testis-specific transcriptional control. Gene 2004; 343:11-22. [PMID: 15563828 DOI: 10.1016/j.gene.2004.08.021] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2004] [Revised: 08/06/2004] [Accepted: 08/19/2004] [Indexed: 01/19/2023]
Abstract
In the testis, tissue-specific transcription is essential for proper expression of the genes that are required for the reproduction of the organism. Many testis-specific genes are required for mitotic proliferation of spermatogonia, spermatocytes undergoing genetic recombination and meiotic divisions, and differentiation of haploid spermatids. In this article we describe some of the genes that are transcribed in male germinal cells and in non-germinal testis cells. Because significant progress has been made in examination of promoter elements and their cognate transcription factors that are involved in controlling transcription of the testis-specific linker histone H1t gene in primary spermatocytes, this work will be reviewed in greater detail. The gene is transcriptionally active in spermatocytes and repressed in all other germinal and non-germinal cell types and, therefore, it serves as a model for study of regulatory mechanisms involved in testis-specific transcription.
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Affiliation(s)
- S R Grimes
- Research Service (151), Overton Brooks Veterans Administration Medical Center, Shreveport, LA 71101-4295, USA.
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12
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Armand AS, Lécolle S, Launay T, Pariset C, Fiore F, Della Gaspera B, Birnbaum D, Chanoine C, Charbonnier F. IGF-II is up-regulated and myofibres are hypertrophied in regenerating soleus of mice lacking FGF6. Exp Cell Res 2004; 297:27-38. [PMID: 15194422 DOI: 10.1016/j.yexcr.2004.02.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2003] [Revised: 02/04/2004] [Indexed: 11/29/2022]
Abstract
Important functions in myogenesis have been proposed for FGF6, a member of the fibroblast growth factor family accumulating almost exclusively in the myogenic lineage. However, the use of FGF6(-/-) mutant mice gave contradictory results and the role of FGF6 during myogenesis remains largely unclear. Using FGF6(-/-) mice, we first analysed the morphology of the regenerated soleus following cardiotoxin injection and showed hypertrophied myofibres in soleus of the mutant mice as compared to wild-type mice. Secondly, to examine the function of the IGF family in the hypertrophy process, we used semiquantitative and real-time RT-PCR assays and Western blots to monitor the expression of the insulin-like growth factors (IGF-I and IGF-II), their receptors [type I IGF receptor (IGF1R) and IGF-II receptor (IGF2R)], and of a binding protein IGFBP-5 in regenerating soleus muscles of FGF6(-/-) knockout mice vs. wild-type mice. In the mutant, both IGF-II and IGF2R, but not IGF-I and IGF1R, were strongly up-regulated, whereas IGFBP5 was down-regulated, strongly suggesting that, in the absence of FGF6, the mechanisms leading to myofibre hypertrophy were mediated specifically by an IGF-II/IGF2R signalling pathway distinct from the classic mechanism involving IGF-I and IGF1R previously described for skeletal muscle hypertrophy. The potential regulating role of IGFBP5 on IGF-II expression is also discussed. This report shows for the first time a specific role for FGF6 in the regulation of myofibre size during a process of in vivo myogenesis.
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MESH Headings
- Animals
- Cobra Cardiotoxin Proteins/pharmacology
- Down-Regulation/genetics
- Fibroblast Growth Factor 6
- Fibroblast Growth Factors/deficiency
- Fibroblast Growth Factors/genetics
- Gene Expression Regulation, Developmental/genetics
- Hypertrophy/metabolism
- Insulin-Like Growth Factor Binding Protein 5/genetics
- Insulin-Like Growth Factor Binding Protein 5/metabolism
- Insulin-Like Growth Factor I/genetics
- Insulin-Like Growth Factor I/metabolism
- Insulin-Like Growth Factor II/genetics
- Insulin-Like Growth Factor II/metabolism
- Mice
- Mice, Knockout
- Muscle Fibers, Skeletal/cytology
- Muscle Fibers, Skeletal/drug effects
- Muscle Fibers, Skeletal/metabolism
- Muscle, Skeletal/cytology
- Muscle, Skeletal/metabolism
- Proto-Oncogene Proteins/deficiency
- Proto-Oncogene Proteins/genetics
- RNA, Messenger/metabolism
- Receptor, IGF Type 1/genetics
- Receptor, IGF Type 1/metabolism
- Receptor, IGF Type 2/genetics
- Receptor, IGF Type 2/metabolism
- Regeneration/genetics
- Signal Transduction/genetics
- Up-Regulation/genetics
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Affiliation(s)
- Anne-Sophie Armand
- UMR 7060 CNRS, Equipe Biologie du Développement et de la Différenciation Neuromusculaire, Centre Universitaire des Saints-Pères, Université René Descartes, F-75270, Paris Cedex 06, France
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13
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Abstract
Although the primary control of gonadotropin secretion is by the hypothalamic GnRH and the gonadal function is controlled by the pituitary gonadotropins and prolactin, the emerging evidence suggests a vital role of the somatotropic axis, growth hormone (GH), and insulin-like growth factor-I (IGF-I) in the control of the pituitary and gonadal functions. It has been shown that GH deficiency, GH resistance, and experimental alterations in IGF-I secretion modify folliculogenesis, ovarian maturation, ovulation, and pregnancy, and in the male, GH/IGF-I plays an important role in spermatogenesis and the Leydig cell function. The primary focus of this review is to examine the role of GH/ IGF-I on the onset of puberty, fertility, pituitary, and gonadal endocrine functions. A number of studies have revealed that fertility is affected in GH-deficient dwarf and in IGF-I gene-ablated mice, possibly due to subnormal function of either the pituitary gland or the gonads. In the female GH receptor gene knockout (GHR-KO) mice, there was impairment in follicular development, ovulation rate, sexual maturation, production of and responsiveness to pheromonal signals, and the corpus luteum function. In IGF-I-deficient male GHR-KO mice, puberty is delayed, spermatogenesis is affected, and neuroendocrine-gonadal function is attenuated. Similarly, in some of the human Laron syndrome patients, puberty is delayed due to GH resistance. These data suggest that, in addition to GnRH and gonadotropins, GH/IGF-I influences the pituitary and gonadal functions in animals and humans.
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Affiliation(s)
- Varadaraj Chandrashekar
- Department of Physiology, Southern Illinois University School of Medicine, Carbondale, Illinois 62901, USA.
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14
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Hawkes C, Kar S. The insulin-like growth factor-II/mannose-6-phosphate receptor: structure, distribution and function in the central nervous system. ACTA ACUST UNITED AC 2004; 44:117-40. [PMID: 15003389 DOI: 10.1016/j.brainresrev.2003.11.002] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/18/2003] [Indexed: 01/25/2023]
Abstract
The insulin-like growth factor-II/mannose-6-phosphate (IGF-II/M6P) receptor is a multifunctional single transmembrane glycoprotein which, along with the cation-dependent M6P (CD-M6P) receptor, mediates the trafficking of M6P-containing lysosomal enzymes from the trans-Golgi network (TGN) to lysosomes. Cell surface IGF-II/M6P receptors also function in the degradation of the non-glycosylated IGF-II polypeptide hormone, as well as in the capture and activation/degradation of extracellular M6P-bearing ligands. In recent years, the multifaceted role of the receptor has become apparent, as several lines of evidence have indicated that in addition to its role in lysosomal enzyme trafficking, clearance and/or activation of a variety of growth factors and endocytosis-mediated degradation of IGF-II, the IGF-II/M6P receptor may also mediate transmembrane signal transduction in response to IGF-II binding under certain conditions. However, very little is known about the physiological significance of the receptor in the function of the central nervous system (CNS). This review aims to delineate what is currently known about IGF-II/M6P receptor structure, its ligand binding properties and role in lysosomal enzyme transport. It also summarizes the recent data regarding the role of the receptor in the CNS, including its distribution, possible importance for normal and activity-dependent functioning as well as its implications in neurodegenerative disorders such as Alzheimer's disease (AD).
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Affiliation(s)
- C Hawkes
- Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada H4H 1R3
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15
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Sivashanmugam P, Hall SH, Hamil KG, French FS, O'Rand MG, Richardson RT. Characterization of mouse Eppin and a gene cluster of similar protease inhibitors on mouse chromosome 2. Gene 2003; 312:125-34. [PMID: 12909348 DOI: 10.1016/s0378-1119(03)00608-5] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We have recently described a novel gene on human chromosome 20q 12-13.2 called Eppin (Epididymal protease inhibitor) that expresses three mRNAs encoding two isoforms of a cysteine-rich protein containing both Kunitz-type and WAP-type (four disulfide core) consensus sequences (Richardson et al., 2001). To further our studies on Eppin, we have cloned, sequenced and characterized mouse Eppin and report that it lies within a 200 Kb cluster of putative Eppin-like genes on mouse chromosome 2. Analysis of the homologies between the genes in the human and mouse Eppin clusters indicates that the first part of the cluster immediately surrounding Eppin represents a conserved linkage because the order of homologous genes is conserved. Sequencing of reverse transcription polymerase chain reaction (RT-PCR) products confirmed the expression of five of these novel Eppin-like genes in the mouse, which include the mouse homologue of HE-4. These genes are characterized by having either one or both of the Kunitz-type and WAP-type consensus sequences. Additional RT-PCR experiments revealed that expression of some of the Eppin-like genes is restricted to epididymis and testis while others are expressed in several somatic tissues. Northern blot analysis of 22 different mouse tissues identified Eppin transcripts only in the epididymis and testis. Immunostaining of Eppin with anti-recombinant mouse Eppin demonstrated Eppin predominantly on the postacrosomal region of mouse spermatozoa, in Sertoli cells, Leydig cells, and round spermatids in the testis, and in the principal cells of the cauda epididymidis epithelium. Eppin is first expressed by Sertoli cells of 12-day-old mice and subsequently in round spermatids, which is consistent with androgen regulation. Our results demonstrate that mouse chromosome 2 contains a conserved linkage of Eppin-like protease inhibitor genes that are expressed in the epididymis.
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Affiliation(s)
- Perumal Sivashanmugam
- Department of Cell and Developmental Biology, 206 Taylor Hall, CB# 7090, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7090, USA
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16
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Ghosh P, Dahms NM, Kornfeld S. Mannose 6-phosphate receptors: new twists in the tale. Nat Rev Mol Cell Biol 2003; 4:202-12. [PMID: 12612639 DOI: 10.1038/nrm1050] [Citation(s) in RCA: 769] [Impact Index Per Article: 36.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The two mannose 6-phosphate (M6P) receptors were identified because of their ability to bind M6P-containing soluble acid hydrolases in the Golgi and transport them to the endosomal-lysosomal system. During the past decade, we have started to understand the structural features of these receptors that allow them to do this job, and how the receptors themselves are sorted as they pass through various membrane-bound compartments. But trafficking of acid hydrolases is only part of the story. Evidence is emerging that one of the receptors can regulate cell growth and motility, and that it functions as a tumour suppressor.
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Affiliation(s)
- Pradipta Ghosh
- Department of Internal Medicine, Washington University School of Medicine, 660 South Euclid Avenue, St Louis, Missouri 63110, USA
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17
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Saris JJ, van den Eijnden MMED, Lamers JMJ, Saxena PR, Schalekamp MADH, Danser AHJ. Prorenin-induced myocyte proliferation: no role for intracellular angiotensin II. Hypertension 2002; 39:573-7. [PMID: 11882610 DOI: 10.1161/hy0202.103002] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Cardiomyocytes bind, internalize, and activate prorenin, the inactive precursor of renin, via a mannose 6-phosphate receptor (M6PR)--dependent mechanism. M6PRs couple directly to G-proteins. To investigate whether prorenin binding to cardiomyocytes elicits a response, and if so, whether this response depends on angiotensin (Ang) II, we incubated neonatal rat cardiomyocytes with 2 nmol/L prorenin and/or 150 nmol/L angiotensinogen, with or without 10 mmol/L M6P, 1 micromol/L eprosartan, or 1 micromol/L PD123319 to block M6P and AT(1) and AT(2) receptors, respectively. Protein and DNA synthesis were studied by quantifying [(3)H]-leucine and [(3)H]-thymidine incorporation. For comparison, studies with 100 nmol/L Ang II were also performed. Neither prorenin alone, nor angiotensinogen alone, affected protein or DNA synthesis. Prorenin plus angiotensinogen increased [(3)H]-leucine incorporation (+21 +/- 5%, mean +/- SEM, P<0.01), [(3)H]-thymidine incorporation (+29 +/- 6%, P<0.01), and total cellular protein (+14 +/- 3%, P<0.01), whereas Ang II increased DNA synthesis only (+34 +/- 7%, P<0.01). Eprosartan, but not PD123319 or M6P, blocked the effects of prorenin plus angiotensinogen as well as the effects of Ang II. Medium Ang II levels during prorenin and angiotensinogen incubation were <1 nmol/L. In conclusion, prorenin binding to M6PRs on cardiomyocytes per se does not result in enhanced protein or DNA synthesis. However, through Ang II generation, prorenin is capable of inducing myocyte hypertrophy and proliferation. Because this generation occurs independently of M6PRs, it most likely depends on the catalytic activity of intact prorenin in the medium (because of temporal prosegment unfolding) rather than its intracellular activation. Taken together, our results do not support the concept of Ang II generation in cardiomyocytes following intracellular prorenin activation.
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Affiliation(s)
- Jasper J Saris
- Cardiovascular Research Institute COEUR, Department of Pharmacology, Erasmus University Medical Center Rotterdam, The Netherlands
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Belmonte SA, Romano PS, Sosa MA. Mannose-6-phosphate receptors as a molecular indicator of maturation of epididymal sperm. ARCHIVES OF ANDROLOGY 2002; 48:53-63. [PMID: 11789684 DOI: 10.1080/014850102753385215] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
This review discusses some of the changes in sperm during maturation within the context of current concepts of membrane structure and fertilization. Mammalian sperm are surrounded by a limiting plasma membrane that undergoes remodeling during passage through the epididymis. This process confers on the gamete vigorous motility and the ability to fertilize the egg. The repositioning of some surface proteins may follow redistribution of lipids in the plasmalemma, and thus represent a critical step in the maturation of the gametes. Among the various affected proteins of the sperm plasmalemma, mannose-6-phosphate receptors undergo redistribution as the gametes transit through the epididymal duct. The authors summarize their studies of the redistribution of phosphomannosyl receptors during maturation of sperm and discuss possible roles of these glycoproteins in the fertilizing capability of sperm.
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Affiliation(s)
- S A Belmonte
- Instituto de Histologia y Embriologia, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina.
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Yamamoto T, Nakayama Y, Abé SI. Mammalian follicle-stimulating hormone and insulin-like growth factor I (IGF-I) up-regulate IGF-I gene expression in organ culture of newt testis. Mol Reprod Dev 2001; 60:56-64. [PMID: 11550268 DOI: 10.1002/mrd.1061] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
We previously showed that porcine follicle-stimulating hormone (pFSH) and human recombinant insulin-like growth factor (rhIGF-I) promote the differentiation of secondary spermatogonia into primary spermatocytes in organ cultures of newt testes, respectively. To elucidate the molecular action of FSH and IGF-I, we cloned cDNAs for newt IGF-I and IGF-I receptor (IGF-IR), and examined their mRNA expression in organ culture during newt spermatogenesis. Northern blot and reverse transcription-polymerase chain reaction (RT-PCR) analyses revealed that IGF-I mRNA was highly expressed in somatic cells (mostly Sertoli cells) at the secondary spermatogonial stage but barely in germ cells, and that IGF-IR mRNA was expressed in both germ and somatic cells at all stages examined. The addition of pFSH to newt testis markedly increased IGF-I mRNA expression. Also, rhIGF-I increased IGF-I mRNA expression, whereas IGF-IR mRNA expression declined slightly. These results suggest that the ability of FSH to promote the differentiation of secondary spermatogonia is at least partly mediated by somatic cell-derived IGF-I, and that IGF-I mRNA expression in somatic cells is auto-upregulated.
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Affiliation(s)
- T Yamamoto
- Department of Biological Science, Faculty of Science, Kumamoto University, Kumamoto, Japan
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