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Farrugia BL, Melrose J. The Glycosaminoglycan Side Chains and Modular Core Proteins of Heparan Sulphate Proteoglycans and the Varied Ways They Provide Tissue Protection by Regulating Physiological Processes and Cellular Behaviour. Int J Mol Sci 2023; 24:14101. [PMID: 37762403 PMCID: PMC10531531 DOI: 10.3390/ijms241814101] [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: 07/24/2023] [Revised: 09/03/2023] [Accepted: 09/05/2023] [Indexed: 09/29/2023] Open
Abstract
This review examines the roles of HS-proteoglycans (HS-PGs) in general, and, in particular, perlecan and syndecan as representative examples and their interactive ligands, which regulate physiological processes and cellular behavior in health and disease. HS-PGs are essential for the functional properties of tissues both in development and in the extracellular matrix (ECM) remodeling that occurs in response to trauma or disease. HS-PGs interact with a biodiverse range of chemokines, chemokine receptors, protease inhibitors, and growth factors in immune regulation, inflammation, ECM stabilization, and tissue protection. Some cell regulatory proteoglycan receptors are dually modified hybrid HS/CS proteoglycans (betaglycan, CD47). Neurexins provide synaptic stabilization, plasticity, and specificity of interaction, promoting neurotransduction, neurogenesis, and differentiation. Ternary complexes of glypican-1 and Robbo-Slit neuroregulatory proteins direct axonogenesis and neural network formation. Specific neurexin-neuroligin complexes stabilize synaptic interactions and neural activity. Disruption in these interactions leads to neurological deficits in disorders of functional cognitive decline. Interactions with HS-PGs also promote or inhibit tumor development. Thus, HS-PGs have complex and diverse regulatory roles in the physiological processes that regulate cellular behavior and the functional properties of normal and pathological tissues. Specialized HS-PGs, such as the neurexins, pikachurin, and Eyes-shut, provide synaptic stabilization and specificity of neural transduction and also stabilize the axenome primary cilium of phototoreceptors and ribbon synapse interactions with bipolar neurons of retinal neural networks, which are essential in ocular vision. Pikachurin and Eyes-Shut interactions with an α-dystroglycan stabilize the photoreceptor synapse. Novel regulatory roles for HS-PGs controlling cell behavior and tissue function are expected to continue to be uncovered in this fascinating class of proteoglycan.
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Affiliation(s)
- Brooke L. Farrugia
- Department of Biomedical Engineering, Faculty of Engineering and Information Technology, University of Melbourne, Melbourne, VIC 3010, Australia;
| | - James Melrose
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW 2052, Australia
- Raymond Purves Laboratory of Bone and Joint Research, Kolling Institute of Medical Research, Northern Sydney Local Health District, Royal North Shore Hospital, St. Leonards, NSW 2065, Australia
- Sydney Medical School (Northern), University of Sydney at Royal North Shore Hospital, St. Leonards, NSW 2065, Australia
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Muthamil S, Kim HY, Jang HJ, Lyu JH, Shin UC, Go Y, Park SH, Lee HG, Park JH. Understanding the relationship between cancer associated cachexia and hypoxia-inducible factor-1. Biomed Pharmacother 2023; 163:114802. [PMID: 37146421 DOI: 10.1016/j.biopha.2023.114802] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 04/24/2023] [Accepted: 04/26/2023] [Indexed: 05/07/2023] Open
Abstract
Cancer-associated cachexia (CAC) is a multifactorial disorder characterized by an unrestricted loss of body weight as a result of muscle and adipose tissue atrophy. Cachexia is influenced by several factors, including decreased metabolic activity and food intake, an imbalance between energy uptake and expenditure, excessive catabolism, and inflammation. Cachexia is highly associated with all types of cancers responsible for more than half of cancer-related mortalities worldwide. In healthy individuals, adipose tissue significantly regulates energy balance and glucose homeostasis. However, in metastatic cancer patients, CAC occurs mainly because of an imbalance between muscle protein synthesis and degradation which are organized by certain extracellular ligands and associated signaling pathways. Under hypoxic conditions, hypoxia-inducible factor-1 (HIF-1α) accumulated and translocated to the nucleus and activate numerous genes involved in cell survival, invasion, angiogenesis, metastasis, metabolic reprogramming, and cancer stemness. On the other hand, the ubiquitination proteasome pathway is inhibited during low O2 levels which promote muscle wasting in cancer patients. Therefore, understanding the mechanism of the HIF-1 pathway and its metabolic adaptation to biomolecules is important for developing a novel therapeutic method for cancer and cachexia therapy. Even though many HIF inhibitors are already in a clinical trial, their mechanism of action remains unknown. With this background, this review summarizes the basic concepts of cachexia, the role of inflammatory cytokines, pathways connected with cachexia with special reference to the HIF-1 pathway and its regulation, metabolic changes, and inhibitors of HIFs.
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Affiliation(s)
- Subramanian Muthamil
- Herbal Medicine Resources Research Center, Korea Institute of Oriental Medicine, Naju, Jeollanam-do, 58245, Republic of Korea
| | - Hyun Yong Kim
- Herbal Medicine Resources Research Center, Korea Institute of Oriental Medicine, Naju, Jeollanam-do, 58245, Republic of Korea
| | - Hyun-Jun Jang
- Herbal Medicine Resources Research Center, Korea Institute of Oriental Medicine, Naju, Jeollanam-do, 58245, Republic of Korea
| | - Ji-Hyo Lyu
- Herbal Medicine Resources Research Center, Korea Institute of Oriental Medicine, Naju, Jeollanam-do, 58245, Republic of Korea
| | - Ung Cheol Shin
- Herbal Medicine Resources Research Center, Korea Institute of Oriental Medicine, Naju, Jeollanam-do, 58245, Republic of Korea
| | - Younghoon Go
- Korean Medicine (KM)-application Center, Korea Institute of Oriental Medicine, Daegu, Republic of Korea
| | - Seong-Hoon Park
- Genetic and Epigenetic Toxicology Research Group, Korea Institute of Toxicology, Daejeon 34141, Republic of Korea
| | - Hee Gu Lee
- Immunotherapy Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, Republic of Korea
| | - Jun Hong Park
- Herbal Medicine Resources Research Center, Korea Institute of Oriental Medicine, Naju, Jeollanam-do, 58245, Republic of Korea; University of Science & Technology (UST), KIOM campus, Korean Convergence Medicine Major, Daejeon 34054, Republic of Korea.
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HS, an Ancient Molecular Recognition and Information Storage Glycosaminoglycan, Equips HS-Proteoglycans with Diverse Matrix and Cell-Interactive Properties Operative in Tissue Development and Tissue Function in Health and Disease. Int J Mol Sci 2023; 24:ijms24021148. [PMID: 36674659 PMCID: PMC9867265 DOI: 10.3390/ijms24021148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/23/2022] [Accepted: 12/27/2022] [Indexed: 01/11/2023] Open
Abstract
Heparan sulfate is a ubiquitous, variably sulfated interactive glycosaminoglycan that consists of repeating disaccharides of glucuronic acid and glucosamine that are subject to a number of modifications (acetylation, de-acetylation, epimerization, sulfation). Variable heparan sulfate chain lengths and sequences within the heparan sulfate chains provide structural diversity generating interactive oligosaccharide binding motifs with a diverse range of extracellular ligands and cellular receptors providing instructional cues over cellular behaviour and tissue homeostasis through the regulation of essential physiological processes in development, health, and disease. heparan sulfate and heparan sulfate-PGs are integral components of the specialized glycocalyx surrounding cells. Heparan sulfate is the most heterogeneous glycosaminoglycan, in terms of its sequence and biosynthetic modifications making it a difficult molecule to fully characterize, multiple ligands also make an elucidation of heparan sulfate functional properties complicated. Spatio-temporal presentation of heparan sulfate sulfate groups is an important functional determinant in tissue development and in cellular control of wound healing and extracellular remodelling in pathological tissues. The regulatory properties of heparan sulfate are mediated via interactions with chemokines, chemokine receptors, growth factors and morphogens in cell proliferation, differentiation, development, tissue remodelling, wound healing, immune regulation, inflammation, and tumour development. A greater understanding of these HS interactive processes will improve therapeutic procedures and prognoses. Advances in glycosaminoglycan synthesis and sequencing, computational analytical carbohydrate algorithms and advanced software for the evaluation of molecular docking of heparan sulfate with its molecular partners are now available. These advanced analytic techniques and artificial intelligence offer predictive capability in the elucidation of heparan sulfate conformational effects on heparan sulfate-ligand interactions significantly aiding heparan sulfate therapeutics development.
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Hayes AJ, Melrose J. Neural Tissue Homeostasis and Repair Is Regulated via CS and DS Proteoglycan Motifs. Front Cell Dev Biol 2021; 9:696640. [PMID: 34409033 PMCID: PMC8365427 DOI: 10.3389/fcell.2021.696640] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 07/13/2021] [Indexed: 01/04/2023] Open
Abstract
Chondroitin sulfate (CS) is the most abundant and widely distributed glycosaminoglycan (GAG) in the human body. As a component of proteoglycans (PGs) it has numerous roles in matrix stabilization and cellular regulation. This chapter highlights the roles of CS and CS-PGs in the central and peripheral nervous systems (CNS/PNS). CS has specific cell regulatory roles that control tissue function and homeostasis. The CNS/PNS contains a diverse range of CS-PGs which direct the development of embryonic neural axonal networks, and the responses of neural cell populations in mature tissues to traumatic injury. Following brain trauma and spinal cord injury, a stabilizing CS-PG-rich scar tissue is laid down at the defect site to protect neural tissues, which are amongst the softest tissues of the human body. Unfortunately, the CS concentrated in gliotic scars also inhibits neural outgrowth and functional recovery. CS has well known inhibitory properties over neural behavior, and animal models of CNS/PNS injury have demonstrated that selective degradation of CS using chondroitinase improves neuronal functional recovery. CS-PGs are present diffusely in the CNS but also form denser regions of extracellular matrix termed perineuronal nets which surround neurons. Hyaluronan is immobilized in hyalectan CS-PG aggregates in these perineural structures, which provide neural protection, synapse, and neural plasticity, and have roles in memory and cognitive learning. Despite the generally inhibitory cues delivered by CS-A and CS-C, some CS-PGs containing highly charged CS disaccharides (CS-D, CS-E) or dermatan sulfate (DS) disaccharides that promote neural outgrowth and functional recovery. CS/DS thus has varied cell regulatory properties and structural ECM supportive roles in the CNS/PNS depending on the glycoform present and its location in tissue niches and specific cellular contexts. Studies on the fruit fly, Drosophila melanogaster and the nematode Caenorhabditis elegans have provided insightful information on neural interconnectivity and the role of the ECM and its PGs in neural development and in tissue morphogenesis in a whole organism environment.
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Affiliation(s)
- Anthony J. Hayes
- Bioimaging Research Hub, Cardiff School of Biosciences, Cardiff University, Wales, United Kingdom
| | - James Melrose
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW, Australia
- Raymond Purves Bone and Joint Research Laboratories, Kolling Institute of Medical Research, Royal North Shore Hospital and The Faculty of Medicine and Health, The University of Sydney, St. Leonard’s, NSW, Australia
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Stangaferro ML, Matiller V, Díaz PU, Ortega HH, Rey F, Rodríguez FM, Silva MA, Salvetti NR. Role of activin, inhibin, and follistatin in the pathogenesis of bovine cystic ovarian disease. Anim Reprod Sci 2014; 148:97-108. [PMID: 25001504 DOI: 10.1016/j.anireprosci.2014.06.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 05/20/2014] [Accepted: 06/19/2014] [Indexed: 11/26/2022]
Abstract
Cystic ovarian disease (COD) is an important cause of infertility in dairy cattle. Although many researchers have focused their work on the endocrine changes related to this disease, evidence indicates that intraovarian components play an important role in follicular persistence. Activin, inhibin, and follistatin participate as intraovarian regulatory molecules involved in follicular cell proliferation, differentiation, steroidogenesis, oocyte maturation, and corpus luteum function. Given the importance of these factors in folliculogenesis, we examined the expression and immunolocalization of activin/inhibin βA-subunit, inhibin α-subunit, and follistatin in the ovaries of healthy estrus-synchronized cows and in those of cows with spontaneous or adrenocorticotropic hormone (ACTH)-induced COD. We also studied inhibin B (α βB) levels in serum and follicular fluid. We found an increased expression of the βA-subunit of activin A/inhibin A, the α-subunit of inhibin, and follistatin in granulosa cells of spontaneous follicular cysts by immunohistochemistry, and decreased concentrations of inhibin B (α βB) in the follicular fluid of spontaneous follicular cysts. These results, together with those previously obtained, indicate that the expression of the components of the activin-inhibin-follistatin system is altered. This could lead to multiple alterations in important functions in the ovary like the balance between pro- and anti-apoptotic factors, follicular proliferation/apoptosis, and steroidogenesis, which may contribute to the follicular persistence and endocrine changes found in cattle with COD.
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Affiliation(s)
- Matías L Stangaferro
- Cátedra de Teriogenología, Facultad de Ciencias Veterinarias, Universidad Nacional del Litoral, Santa Fe, Argentina
| | - Valentina Matiller
- Laboratorio de Biología Celular y Molecular Aplicada, Facultad de Ciencias Veterinarias, Universidad Nacional del Litoral, Santa Fe, Argentina; Instituto de Ciencias Veterinarias del Litoral (ICiVet-Litoral), Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Buenos Aires, Argentina
| | - Pablo U Díaz
- Laboratorio de Biología Celular y Molecular Aplicada, Facultad de Ciencias Veterinarias, Universidad Nacional del Litoral, Santa Fe, Argentina; Instituto de Ciencias Veterinarias del Litoral (ICiVet-Litoral), Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Buenos Aires, Argentina
| | - Hugo H Ortega
- Laboratorio de Biología Celular y Molecular Aplicada, Facultad de Ciencias Veterinarias, Universidad Nacional del Litoral, Santa Fe, Argentina; Instituto de Ciencias Veterinarias del Litoral (ICiVet-Litoral), Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Buenos Aires, Argentina
| | - Florencia Rey
- Laboratorio de Biología Celular y Molecular Aplicada, Facultad de Ciencias Veterinarias, Universidad Nacional del Litoral, Santa Fe, Argentina; Instituto de Ciencias Veterinarias del Litoral (ICiVet-Litoral), Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Buenos Aires, Argentina
| | - Fernanda M Rodríguez
- Laboratorio de Biología Celular y Molecular Aplicada, Facultad de Ciencias Veterinarias, Universidad Nacional del Litoral, Santa Fe, Argentina; Instituto de Ciencias Veterinarias del Litoral (ICiVet-Litoral), Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Buenos Aires, Argentina
| | - Manuel A Silva
- Laboratorio de Biología Celular y Molecular Aplicada, Facultad de Ciencias Veterinarias, Universidad Nacional del Litoral, Santa Fe, Argentina
| | - Natalia R Salvetti
- Laboratorio de Biología Celular y Molecular Aplicada, Facultad de Ciencias Veterinarias, Universidad Nacional del Litoral, Santa Fe, Argentina; Instituto de Ciencias Veterinarias del Litoral (ICiVet-Litoral), Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Buenos Aires, Argentina.
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Myostatin/activin pathway antagonism: Molecular basis and therapeutic potential. Int J Biochem Cell Biol 2013; 45:2333-47. [DOI: 10.1016/j.biocel.2013.05.019] [Citation(s) in RCA: 198] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Revised: 05/17/2013] [Accepted: 05/18/2013] [Indexed: 11/21/2022]
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Scaramuzzi RJ, Baird DT, Campbell BK, Driancourt MA, Dupont J, Fortune JE, Gilchrist RB, Martin GB, McNatty KP, McNeilly AS, Monget P, Monniaux D, Viñoles C, Webb R. Regulation of folliculogenesis and the determination of ovulation rate in ruminants. Reprod Fertil Dev 2011; 23:444-67. [DOI: 10.1071/rd09161] [Citation(s) in RCA: 185] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2009] [Accepted: 10/05/2010] [Indexed: 11/23/2022] Open
Abstract
The paper presents an update of our 1993 model of ovarian follicular development in ruminants, based on knowledge gained from the past 15 years of research. The model addresses the sequence of events from follicular formation in fetal life, through the successive waves of follicular growth and atresia, culminating with the emergence of ovulatory follicles during reproductive cycles. The original concept of five developmental classes of follicles, defined primarily by their responses to gonadotrophins, is retained: primordial, committed, gonadotrophin-responsive, gonadotrophin-dependent and ovulatory follicles. The updated model has more extensive integration of the morphological, molecular and cellular events during folliculogenesis with systemic events in the whole animal. It also incorporates knowledge on factors that influence oocyte quality and the critical roles of the oocyte in regulating follicular development and ovulation rate. The original hypothetical mechanisms determining ovulation rate are retained but with some refinements; the enhanced viability of gonadotrophin-dependent follicles and increases in the number of gonadotrophin-responsive follicles by increases in the throughput of follicles to this stage of growth. Finally, we reexamine how these two mechanisms, which are thought not to be mutually exclusive, appear to account for most of the known genetic and environmental effects on ovulation rate.
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McCarthy TL, Pham TH, Knoll BI, Centrella M. Prostaglandin E2 increases transforming growth factor-beta type III receptor expression through CCAAT enhancer-binding protein delta in osteoblasts. Mol Endocrinol 2007; 21:2713-24. [PMID: 17636036 DOI: 10.1210/me.2007-0210] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Variations in individual TGF-beta receptors (TbetaRs) may modify TGF-beta activity and significantly alter its effects on connective tissue growth or repair. Differences in the amount of TbetaR type III (TbetaRIII) relative to signal transducing TbetaRI occur on bone cells during differentiation or in response to other growth regulators. Here we investigated prostaglandin (PG) E2, a potent effector during trauma, inflammation, or mechanical load, on TbetaR expression in primary osteoblast-enriched cultures. PGE2 rapidly increased TbetaRIII mRNA and protein expression and enhanced TbetaRIII gene promoter activity through a discrete region within 0.4 kb of the transcription start site. PGE2 alters osteoblast function through multiple signal-inducing pathways. In this regard, protein kinase A (PKA) activators, PGE1 and forskolin, also enhanced gene expression through the TbetaRIII gene promoter, whereas protein kinase C activators, PGF2alpha and phorbol myristate acetate, did not. The stimulatory effect of PGE2 on TbetaRIII promoter activity was suppressed by a dominant negative PKA-regulatory subunit, but not by dominant negative protein kinase C. PGE2 specifically increased nuclear factor CCAAT enhancer-binding protein delta (C/EBPdelta) binding to a half-binding site upstream of the basal TbetaRIII promoter region, and promoter activity was sensitive to C/EBPdelta overexpression and to dominant-negative C/EBPdelta competition. In parallel with their effect on TbetaRIII expression, activators of PKA decreased TGF-beta-induced activity. In summary, high levels of PGE2 that occur with inflammation or trauma may, through PKA-activated C/EBPdelta, preferentially increase TbetaRIII expression and in this way delay TGF-beta-dependent activation of osteoblasts during the early stabilization phase of bone repair.
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Affiliation(s)
- Thomas L McCarthy
- Department of Surgery and Section of Plastic Surgery, Yale University School of Medicine, New Haven, Connecticut 06520, USA.
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Cabello-Verrugio C, Brandan E. A novel modulatory mechanism of transforming growth factor-beta signaling through decorin and LRP-1. J Biol Chem 2007; 282:18842-50. [PMID: 17485468 DOI: 10.1074/jbc.m700243200] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Transforming growth factor-beta (TGF-beta) is a multifunctional cytokine that signals to the nucleus through cell surface transmembrane receptors with serine/threonine kinase activity and cytoplasmic effectors, including Smad proteins. Here we describe two novel modulators of this pathway, lipoprotein-receptor related protein (LRP-1) and decorin. Decorin null (Dcn null) myoblasts showed a diminished TGF-beta response that is restored by decorin re-expression. Importantly, this reactivation occurs without changes in the binding to TGF-beta receptors, Smad protein phosphorylation, or Smad-4 nuclear translocation. In wild type myoblasts, inhibition of decorin binding to LRP-1 and depletion of LRP-1 inhibited TGF-beta response to levels similar to those observed in Dcn null myoblasts. Re-expression of decorin in Dcn null myoblasts cannot restore TGF-beta response if the Smad pathway or phosphatidylinositol 3-kinase activity is inhibited, suggesting that this LRP-1-decorin modulatory pathway requires activation of the Smad pathway by TGF-beta and involves phosphatidylinositol 3-kinase activity. This work unveils a new regulatory mechanism for TGF-beta signaling by decorin and LRP-1.
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Affiliation(s)
- Claudio Cabello-Verrugio
- Centro de Regulación Celular y Patología, Departamento de Biología Celular y Molecular, Facultad Millennium Institute for Fundamental and Applied Biology (MIFAB), Pontificia Universidad Católica de Chile, Casilla 114-D Santiago, Chile
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Davis JRE, McNeilly JR, Norris AJ, Pope C, Wilding M, McDowell G, Holland JP, McNeilly AS. Fetal gonadotrope cell origin of FSH-secreting pituitary adenoma - insight into human pituitary tumour pathogenesis. Clin Endocrinol (Oxf) 2006; 65:648-54. [PMID: 17054468 DOI: 10.1111/j.1365-2265.2006.02644.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE The pathogenesis of human pituitary adenomas remains unclear, but we report a case of FSH-secreting pituitary adenoma whose monohormonal phenotype suggests it was of fetal origin. PATIENTS A 28-year-old woman presented with abdominal discomfort and irregular menses, enlarged multicystic ovaries and elevated serum oestradiol, with sustained high-normal FSH and low LH levels. MEASUREMENTS Endocrine studies were performed before and after curative surgery, with assessment of tumour hormone secretion in vitro, and immunostaining of tumour tissue for a series of gonadotrope proteins. RESULTS Immunocytochemistry showed that tumour cells were monohormonal for FSH. Normal components of gonadotrope signalling pathways were expressed, including oestrogen receptor-alpha, activin receptors, secretogranin-II and chromogranin-A. beta-glycan, the putative inhibin coreceptor, was absent. Tumour culture in vitro confirmed secretion of FSH with minimal LH, that was unsuppressed by oestradiol or inhibin-A. Human fetal pituitary tissue contained FSH-only cells at 18 weeks gestation, whereas normal adult pituitary tissue contained only bihormonal gonadotropes. CONCLUSIONS We propose that this pituitary adenoma represents an indolent tumour of monohormonal fetal gonadotrope cells that originated early in gestation. Pituitary tumours may therefore arise from abnormal persistence of fetal cell types, with extremely slow growth over many years until reaching a size threshold to generate an endocrine syndrome. Understanding fetal pituitary architecture and function may be more informative for new insights into pituitary tumour pathogenesis than classical theories of cancer biology that invoke unrestrained cell proliferation.
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Affiliation(s)
- J R E Davis
- Endocrine Sciences Research Group, University of Manchester, UK.
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Kobayashi Y, Jimenez-Krassel F, Ireland JJ, Smith GW. Evidence of a local negative role for cocaine and amphetamine regulated transcript (CART), inhibins and low molecular weight insulin like growth factor binding proteins in regulation of granulosa cell estradiol production during follicular waves in cattle. Reprod Biol Endocrinol 2006; 4:22. [PMID: 16611367 PMCID: PMC1459166 DOI: 10.1186/1477-7827-4-22] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2005] [Accepted: 04/12/2006] [Indexed: 12/21/2022] Open
Abstract
The ability of ovarian follicles to produce large amounts of estradiol is a hallmark of follicle health status. Estradiol producing capacity is lost in ovarian follicles before morphological signs of atresia. A prominent wave like pattern of growth of antral follicles is characteristic of monotocous species such as cattle, horses and humans. While our knowledge of the role of pituitary gonadotropins in support of antral follicle growth and development is well established, the intrinsic factors that suppress estradiol production and may help promote atresia during follicular waves are not well understood. Numerous growth factors and cytokines have been reported to suppress granulosa cell estradiol production in vitro, but the association of expression of many such factors in vivo with follicle health status and their physiological significance are not clear. The purpose of this review is to discuss the in vivo and in vitro evidence supporting a local physiological role for cocaine and amphetamine regulated transcript, inhibins and low molecular weight insulin like growth factor binding proteins in negative regulation of granulosa cell estradiol production, with emphasis on evidence from the bovine model system.
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Affiliation(s)
- Yasuhiro Kobayashi
- Department of Animal Science, Michigan State University, East Lansing, MI, USA
| | | | - James J Ireland
- Department of Animal Science, Michigan State University, East Lansing, MI, USA
- Department of Physiology, Michigan State University, East Lansing, MI, USA
| | - George W Smith
- Department of Animal Science, Michigan State University, East Lansing, MI, USA
- Department of Physiology, Michigan State University, East Lansing, MI, USA
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Ball EMA, Mellor SL, Risbridger GP. Cancer progression: is inhibin alpha from Venus or Mars? Cytokine Growth Factor Rev 2005; 15:291-6. [PMID: 15450247 DOI: 10.1016/j.cytogfr.2004.04.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The inhibin field has been perplexed by the information that inhibin alpha is a tumour suppressor in mice yet is elevated in women with ovarian cancer. Furthermore, we have consistently observed a down-regulation or loss of inhibin alpha in prostate cancer patient samples and cell lines. However, our latest data have prompted us to re-evaluate the role of inhibin alpha in prostate and other cancers. Using the analogy of TGF-beta as a springboard for our hypothesis, we offer a unifying model whereby the previously conflicting observations in mice, men and women can be explained. We propose that initially inhibin alpha is tumour-suppressive and is expressed in benign and early-stage primary cancers. Tumour-suppressive inhibin alpha is then silenced as the tumour progresses but is reactivated as a pro-metastatic factor in advanced, aggressive cancers.
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Affiliation(s)
- Emma M A Ball
- Centre for Urological Research, Monash Institute of Reproduction and Development, Monash University, 246 Clayton Rd, Clayton, Vic. 3168, Australia
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Boström K, Zebboudj AF, Yao Y, Lin TS, Torres A. Matrix GLA protein stimulates VEGF expression through increased transforming growth factor-beta1 activity in endothelial cells. J Biol Chem 2004; 279:52904-13. [PMID: 15456771 DOI: 10.1074/jbc.m406868200] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Matrix GLA protein (MGP) is expressed in endothelial cells (EC), and MGP deficiency results in developmental defects suggesting involvement in EC function. To determine the role of MGP in EC, we cultured bovine aortic EC with increasing concentrations of human MGP (hMGP) for 24 h. The results showed increased proliferation, migration, tube formation, and increased release of vascular endothelial growth factor-A (VEGF-A) and basic fibroblast growth factor (bFGF). HMGP, added endogenously or transiently expressed, increased VEGF gene expression dose-dependently as determined by real-time PCR. To determine the mechanism by which hMGP increased VEGF expression, we studied the effect of MGP on the activity of transforming growth factor (TGF)-beta1 compared with that of bone morphogenetic protein (BMP)-2 using transfection assays with TGF-beta- and BMP-response element reporter genes. Our results showed a strong enhancement of TGF-beta1 activity by hMGP, which was paralleled by increased VEGF expression. BMP-2 activity, on the other hand, was inhibited by hMGP. Neutralizing antibodies to TGF-beta blocked the effect of MGP on VEGF expression. The enhanced TGF-beta1 activity specifically activated the Smad1/5 pathway indicating that the TGF-beta receptor activin-like kinase 1 (ALK1) had been stimulated. It occurred without changes in expression of TGF-beta1 or ALK1 and was mimicked by transfection of constitutively active ALK1, which increased VEGF expression. Expression of VEGF and MGP was induced by TGF-beta1, but the induction of MGP preceded that of VEGF, consistent with a promoting effect on VEGF expression. Together, the results suggest that MGP plays a role in EC function, altering the response to TGF-beta superfamily growth factors.
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Affiliation(s)
- Kristina Boström
- Division of Cardiology, David Geffen School of Medicine, University of California, Box 951679, Rm. 47-123 CHS, Los Angeles, CA 90095-1679, USA.
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Kumar TR, Agno J, Janovick JA, Conn PM, Matzuk MM. Regulation of FSHbeta and GnRH receptor gene expression in activin receptor II knockout male mice. Mol Cell Endocrinol 2003; 212:19-27. [PMID: 14654247 DOI: 10.1016/j.mce.2003.09.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
To examine in vivo, the local effects of inhibins and activins within the anterior pituitary, independent of their endocrine effects exerted from the gonad, in mediating FSH homeostasis, we used castrated knockout mice lacking either inhibin alpha or activin receptor II (ACVR2) alone or in combination. Compared to castrated wild-type (WT) mice, FSHbeta mRNA levels in the pituitaries of Acvr2 null mice were significantly downregulated in the absence of gonadal feedback. FSHbeta mRNA levels were not significantly higher in the pituitaries of castrated inhibin alpha null mice compared to those in Acvr2 null mice and remained the same in the pituitaries of castrated double mutant mice lacking both inhibin and ACVR2. In contrast to FSHbeta mRNA expression changes, pituitary FSH content was significantly reduced in Acvr2 null mice whereas it was only slightly upregulated in inhibin alpha null mice. Combined absence of both ACVR2 signaling and inhibins caused a decrease in FSH content compared to that in the absence of inhibins alone. These changes in pituitary content were in parallel to those in serum FSH levels in these three groups of castrated mice, suggesting that the unopposed actions of locally produced inhibins are dominant over those effects mediated by ACVR2 signaling to regulate FSH biosynthesis and secretion. Thus, our in vivo results demonstrate that within the pituitary, locally produced activins and inhibins exert their actions at distinct phases of FSH homeostasis. In an independent set of experiments, we tested whether in vivo signaling via ACVR2 is necessary for hypothalamic GnRH biosynthesis and for GnRH receptor expression. Our results demonstrate that in contrast to previous in vitro studies, signaling through ACVR2 is neither required for hypothalamic synthesis of GnRH peptide nor for expression of GnRH receptors in the anterior pituitary. We conclude that within the hypothalamic-pituitary short loop, ACVR2 signaling is critical only for FSH homeostasis and not for GnRH biosynthesis or induction of pituitary GnRH receptor expression. Our studies confirm the importance of using in vivo genetic models for studying regulation of the hypothalamic-pituitary-gonadal axis.
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Affiliation(s)
- T Rajendra Kumar
- Department of Pathology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA.
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15
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Bilezikjian LM, Leal AMO, Blount AL, Corrigan AZ, Turnbull AV, Vale WW. Rat anterior pituitary folliculostellate cells are targets of interleukin-1beta and a major source of intrapituitary follistatin. Endocrinology 2003; 144:732-40. [PMID: 12538636 DOI: 10.1210/en.2002-220703] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Folliculostellate cells of the anterior pituitary are postulated to be an important source of factors, such as follistatin, that regulate pituitary function by intercellular communication. To gain further insight into the function of this cell type, folliculostellate cells were enriched from cultured rat anterior pituitary cells, and an immortalized cell line designated FS/D1h was established and characterized. These FS/D1h cells express S100 immunoreactivity and produce IL-6 but not pituitary hormones such as GH, ACTH, FSH, and LH. Importantly, FS/D1h cells express large amounts of follistatin mRNA and secrete the protein, as quantified indirectly by the amount of [(125)I]activin A immunoprecipitated with a follistatin antiserum. The FS/D1h cells also express alpha, betaA, and betaB inhibin/activin subunit mRNAs, but whether they produce the corresponding activins and inhibins has not been determined. The response of FS/D1h cells to agents thought to modulate folliculostellate cell function was evaluated. IL-1beta (0.005-5 nM) stimulated the secretion of follistatin and increased mRNA expression. In parallel, IL-6 secretion was stimulated. Dexamethasone, pituitary adenylate cyclase-activating polypeptide(1-27), and lipopolysaccharide but not testosterone, 12-O-tetradecanoylphorbol-13-acetate, or forskolin also increased follistatin secretion. Surprisingly, activin had no effect on follistatin mRNA levels, despite the fact that FS/D1h cells express ActRII, ActRIIB, and ALK-4 (ActRIB). Activin, on the other hand, induced Smad7 mRNA accumulation and exerted an antiproliferative effect on FS/D1h cells. Altogether, these observations support the possibility that follistatin originating from folliculostellate cells participates in mediating the effects of IL-1beta, glucocorticoids, and other agents on the response of pituitary cells to activins.
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Affiliation(s)
- Louise M Bilezikjian
- Clayton Foundation Laboratories for Peptide Biology, The Salk Institute, La Jolla, California 92037, USA.
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16
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Abstract
The final stages of ovarian follicle growth in cattle are typically characterized by the ultrasound-detectable emergence of a cohort of small (3-5mm in diameter) antral follicles, followed by a selection process during which the number of follicles continuing to grow decreases. Finally, only one follicle (the dominant follicle; DF) shows an enhanced growth rate and estradiol synthesis when it attains 8.5mm compared to its closest competitor (the largest subordinate follicle; SF). Cohort emergence is caused by a transient FSH rise, while DF selection occurs during declining FSH indicating differential FSH dependence of DF and SF. In order to elucidate the mechanisms underlying DF survival or SF atresia, this review aims to (i) describe follicular changes in the local production and regulation of members of the inhibin family of proteins and the insulin-like growth factor (IGF) system in relation to FSH deprivation leading to DF selection, and (ii) develop a model for DF selection outlining the putative involvement of inhibins, activin and follistatin on the one hand, and bioavailable IGFs regulated by IGF binding proteins (IGFBPs) and IGFBP proteases on the other hand. It is concluded, that the first indications of differential FSH dependence are seen within 33h of the FSH peak, and high amounts of precursor forms of inhibin and free activin, and low amounts of the lower molecular weight (MW) IGFBPs are related to follicle survival in terms of enhanced growth and estradiol synthesis, and suppression of granulosa cell apoptosis. In addition, maintenance of low amounts of intrafollicular IGFBP4 may constitute an important mechanism in the future DF to attain FSH independence.
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Affiliation(s)
- M Mihm
- Department of Veterinary Preclinical Studies, University of Glasgow Veterinary School, Bearsden Road, UK.
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17
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Welt CK. The physiology and pathophysiology of inhibin, activin and follistatin in female reproduction. Curr Opin Obstet Gynecol 2002; 14:317-23. [PMID: 12032389 DOI: 10.1097/00001703-200206000-00012] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In the last 2 years, major advances have been made in the understanding of inhibin physiology. Discovery of an inhibin receptor and binding protein has expanded our knowledge of the mechanism whereby inhibin antagonizes activin action. Controlled experimental studies have clarified the regulation and physiology of inhibin A and inhibin B, providing evidence for their use as markers of ovarian function. Clinical studies continue to uphold the use of inhibin as a marker for ovarian cancer, but have not generally supported its use over standard prognostic markers in assisted reproductive technologies. Finally, ongoing work suggests alterations in inhibin and follistatin that may be linked to the pathophysiology of polycystic ovary syndrome. Thus, the mechanism of inhibin action and its role in normal and abnormal ovarian function continues to emerge.
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Affiliation(s)
- Corrine K Welt
- Reproductive Endocrine Unit, Reproductive Endocrine Sciences Center and National Center for Infertility Research, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts 02114, USA.
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18
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Jones RL, Salamonsen LA, Findlay JK. Potential roles for endometrial inhibins, activins and follistatin during human embryo implantation and early pregnancy. Trends Endocrinol Metab 2002; 13:144-50. [PMID: 11943557 DOI: 10.1016/s1043-2760(01)00559-8] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The human endometrium is a remarkably dynamic tissue, undergoing cycles of proliferation, differentiation and breakdown every 28 days. In preparation for embryo implantation, the endometrium differentiates or decidualizes, involving widespread morphological and functional differentiation of endometrial stromal cells. If pregnancy occurs, the decidua regulates trophoblast invasion and forms the maternal component of the placenta. Uterine remodeling has long been known to be regulated by the ovarian steroid hormones 17beta-estradiol and progesterone; however, only recently has the importance of paracrine factors in mediating the cellular and biochemical changes been recognized. Many growth factors and cytokines, such as inhibins and activins, whose expression is generally limited to developmental and pathological states, are produced by actively remodeling endometrial cells, and play crucial roles in regulating endometrial cell function. Here, we present evidence for integral roles for the inhibin and activin family in the paracrine regulation of endometrial receptivity, decidualization and implantation.
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Affiliation(s)
- Rebecca L Jones
- Prince Henry's Institute of Medical Research, PO Box 5152, VIC 3168, Clayton, Australia.
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Bernard DJ, Chapman SC, Woodruff TK. Inhibin binding protein (InhBP/p120), betaglycan, and the continuing search for the inhibin receptor. Mol Endocrinol 2002; 16:207-12. [PMID: 11818494 DOI: 10.1210/mend.16.2.0783] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Betaglycan (the TGFbeta type III receptor) and InhBP/p120 (a membrane-tethered proteoglycan) were recently identified as putative inhibin receptors. Here, we review the current state of knowledge regarding these two proteins with respect to their potential roles in inhibin biology. Importantly, neither protein appears to satisfy all of the criteria required for classification as a bona fide inhibin receptor. Betaglycan does not appear to be expressed in pituitary gonadotropes, the primary target of circulating inhibins, and InhBP/p120 does not bind inhibins in conventional receptor binding assays. While both proteins appear capable of promoting inhibin-mediated antagonism of activin signaling, neither appears to generate inhibin-specific intracellular signals. Recently, additional inhibin binding proteins were identified in inhibin target tissues, including pituitary and Leydig cells. Characterization of these proteins, coupled with ongoing investigations of betaglycan and InhBP/p120, will lead to a clearer understanding of mechanisms of inhibin action.
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Affiliation(s)
- Daniel J Bernard
- Department of Neurobiology and Physiology, Northwestern University, Evanston, Illinois 60208, USA
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