1
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Bardsley EN, Paterson DJ. Neurocardiac regulation: from cardiac mechanisms to novel therapeutic approaches. J Physiol 2020; 598:2957-2976. [PMID: 30307615 PMCID: PMC7496613 DOI: 10.1113/jp276962] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 10/02/2018] [Indexed: 12/15/2022] Open
Abstract
Cardiac sympathetic overactivity is a well-established contributor to the progression of neurogenic hypertension and heart failure, yet the underlying pathophysiology remains unclear. Recent studies have highlighted the importance of acutely regulated cyclic nucleotides and their effectors in the control of intracellular calcium and exocytosis. Emerging evidence now suggests that a significant component of sympathetic overactivity and enhanced transmission may arise from impaired cyclic nucleotide signalling, resulting from compromised phosphodiesterase activity, as well as alterations in receptor-coupled G-protein activation. In this review, we address some of the key cellular and molecular pathways that contribute to sympathetic overactivity in hypertension and discuss their potential for therapeutic targeting.
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Affiliation(s)
- E. N. Bardsley
- Wellcome Trust OXION Initiative in Ion Channels and DiseaseOxfordUK
- Burdon Sanderson Cardiac Science Centre, Department of PhysiologyAnatomy and Genetics, University of OxfordOxfordOX1 3PTUK
| | - D. J. Paterson
- Wellcome Trust OXION Initiative in Ion Channels and DiseaseOxfordUK
- Burdon Sanderson Cardiac Science Centre, Department of PhysiologyAnatomy and Genetics, University of OxfordOxfordOX1 3PTUK
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2
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Bardsley EN, Neely OC, Paterson DJ. Angiotensin peptide synthesis and cyclic nucleotide modulation in sympathetic stellate ganglia. J Mol Cell Cardiol 2020; 138:234-243. [PMID: 31836539 PMCID: PMC7049903 DOI: 10.1016/j.yjmcc.2019.11.157] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 11/25/2019] [Accepted: 11/26/2019] [Indexed: 12/12/2022]
Abstract
Chronically elevated angiotensin II is a widely-established contributor to hypertension and heart failure via its action on the kidneys and vasculature. It also augments the activity of peripheral sympathetic nerves through activation of presynaptic angiotensin II receptors, thus contributing to sympathetic over-activity. Although some cells can synthesise angiotensin II locally, it is not known if this machinery is present in neurons closely coupled to the heart. Using a combination of RNA sequencing and quantitative real-time polymerase chain reaction, we demonstrate evidence for a renin-angiotensin synthesis pathway within human and rat sympathetic stellate ganglia, where significant alterations were observed in the spontaneously hypertensive rat stellate ganglia compared with Wistar stellates. We also used Förster Resonance Energy Transfer to demonstrate that administration of angiotensin II and angiotensin 1-7 peptides significantly elevate cyclic guanosine monophosphate in the rat stellate ganglia. Whether the release of angiotensin peptides from the sympathetic stellate ganglia alters neurotransmission and/or exacerbates cardiac dysfunction in states associated with sympathetic over activity remains to be established.
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Affiliation(s)
- Emma N Bardsley
- Wellcome Trust OXION Initiative in Ion Channels and Disease, Oxford, UK; Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK; British Heart Foundation, Centre of Research Excellence, UK.
| | - Oliver C Neely
- Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK; British Heart Foundation, Centre of Research Excellence, UK
| | - David J Paterson
- Wellcome Trust OXION Initiative in Ion Channels and Disease, Oxford, UK; Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK; British Heart Foundation, Centre of Research Excellence, UK.
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3
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Bahadoran Z, Mirmiran P, Azizi F, Ghasemi A. A Brief History of Modern Endocrinology and Definitions of a True Hormone. Endocr Metab Immune Disord Drug Targets 2019; 19:1116-1121. [DOI: 10.2174/1871530319666190326142908] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2018] [Revised: 03/03/2019] [Accepted: 03/06/2019] [Indexed: 11/22/2022]
Abstract
Background and Objective:
An overview of the history of endocrinology indicates that
definitions of some initially developed concepts, including the term ‘hormone’ have been changed over
time. This review provides a historical overview of current definitions of ‘hormone’ and the criteria of
a true hormone. In addition, a brief history of hormone-related concepts and their transformation over
time are discussed.
Results:
Classically, a hormone is a chemical substance secreted into the bloodstream and acts on distant
tissues, usually in a regulatory fashion. Several newly discovered bioregulators and chemical signaling
molecules are far from the classical definition of a true hormone and could not fulfill many relevant
criteria. Major developments in the field of endocrinology accompanied by the complex terminology,
currently used to describe hormonal actions of chemical messengers, underscore the need of the
revision of such classical concepts.
Conclusion:
Complex terminology currently used to describe different hormonal actions of chemical
messengers, suggests that it is time to conceptualize the term hormone and revise its classical definition.
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Affiliation(s)
- Zahra Bahadoran
- Nutrition and Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Parvin Mirmiran
- Department of Clinical Nutrition and Diet Therapy, Faculty of Nutrition Sciences and Food Technology, National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Fereidoun Azizi
- Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Asghar Ghasemi
- Endocrine Physiology Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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4
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Canaider S, Facchin F, Tassinari R, Cavallini C, Olivi E, Taglioli V, Zannini C, Bianconi E, Maioli M, Ventura C. Intracrine Endorphinergic Systems in Modulation of Myocardial Differentiation. Int J Mol Sci 2019; 20:ijms20205175. [PMID: 31635381 PMCID: PMC6829321 DOI: 10.3390/ijms20205175] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 10/11/2019] [Accepted: 10/16/2019] [Indexed: 12/12/2022] Open
Abstract
A wide variety of peptides not only interact with the cell surface, but govern complex signaling from inside the cell. This has been referred to as an "intracrine" action, and the orchestrating molecules as "intracrines". Here, we review the intracrine action of dynorphin B, a bioactive end-product of the prodynorphin gene, on nuclear opioid receptors and nuclear protein kinase C signaling to stimulate the transcription of a gene program of cardiogenesis. The ability of intracrine dynorphin B to prime the transcription of its own coding gene in isolated nuclei is discussed as a feed-forward loop of gene expression amplification and synchronization. We describe the role of hyaluronan mixed esters of butyric and retinoic acids as synthetic intracrines, controlling prodynorphin gene expression, cardiogenesis, and cardiac repair. We also discuss the increase in prodynorphin gene transcription and intracellular dynorphin B afforded by electromagnetic fields in stem cells, as a mechanism of cardiogenic signaling and enhancement in the yield of stem cell-derived cardiomyocytes. We underline the possibility of using the diffusive features of physical energies to modulate intracrinergic systems without the needs of viral vector-mediated gene transfer technologies, and prompt the exploration of this hypothesis in the near future.
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Affiliation(s)
- Silvia Canaider
- National Laboratory of Molecular Biology and Stem Cell Bioengineering - Eldor Lab, National Institute of Biostructures and Biosystems (NIBB), at the Innovation Accelerator, CNR, Via Piero Gobetti 101, 40129 Bologna, Italy.
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, Via Massarenti 9, 40138 Bologna, Italy.
| | - Federica Facchin
- National Laboratory of Molecular Biology and Stem Cell Bioengineering - Eldor Lab, National Institute of Biostructures and Biosystems (NIBB), at the Innovation Accelerator, CNR, Via Piero Gobetti 101, 40129 Bologna, Italy.
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, Via Massarenti 9, 40138 Bologna, Italy.
| | - Riccardo Tassinari
- National Laboratory of Molecular Biology and Stem Cell Bioengineering - Eldor Lab, National Institute of Biostructures and Biosystems (NIBB), at the Innovation Accelerator, CNR, Via Piero Gobetti 101, 40129 Bologna, Italy.
| | - Claudia Cavallini
- National Laboratory of Molecular Biology and Stem Cell Bioengineering - Eldor Lab, National Institute of Biostructures and Biosystems (NIBB), at the Innovation Accelerator, CNR, Via Piero Gobetti 101, 40129 Bologna, Italy.
| | - Elena Olivi
- National Laboratory of Molecular Biology and Stem Cell Bioengineering - Eldor Lab, National Institute of Biostructures and Biosystems (NIBB), at the Innovation Accelerator, CNR, Via Piero Gobetti 101, 40129 Bologna, Italy.
| | - Valentina Taglioli
- National Laboratory of Molecular Biology and Stem Cell Bioengineering - Eldor Lab, National Institute of Biostructures and Biosystems (NIBB), at the Innovation Accelerator, CNR, Via Piero Gobetti 101, 40129 Bologna, Italy.
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, Via Massarenti 9, 40138 Bologna, Italy.
| | - Chiara Zannini
- National Laboratory of Molecular Biology and Stem Cell Bioengineering - Eldor Lab, National Institute of Biostructures and Biosystems (NIBB), at the Innovation Accelerator, CNR, Via Piero Gobetti 101, 40129 Bologna, Italy.
| | - Eva Bianconi
- National Laboratory of Molecular Biology and Stem Cell Bioengineering - Eldor Lab, National Institute of Biostructures and Biosystems (NIBB), at the Innovation Accelerator, CNR, Via Piero Gobetti 101, 40129 Bologna, Italy.
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, Via Massarenti 9, 40138 Bologna, Italy.
| | - Margherita Maioli
- Department of Biomedical Sciences, University of Sassari, Viale San Pietro 43/B, 07100 Sassari, Italy.
| | - Carlo Ventura
- National Laboratory of Molecular Biology and Stem Cell Bioengineering - Eldor Lab, National Institute of Biostructures and Biosystems (NIBB), at the Innovation Accelerator, CNR, Via Piero Gobetti 101, 40129 Bologna, Italy.
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, Via Massarenti 9, 40138 Bologna, Italy.
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5
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Mani I, Pandey KN. Emerging concepts of receptor endocytosis and concurrent intracellular signaling: Mechanisms of guanylyl cyclase/natriuretic peptide receptor-A activation and trafficking. Cell Signal 2019; 60:17-30. [PMID: 30951863 DOI: 10.1016/j.cellsig.2019.03.022] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 03/27/2019] [Accepted: 03/28/2019] [Indexed: 12/15/2022]
Abstract
Endocytosis is a prominent clathrin-mediated mechanism for concentrated uptake and internalization of ligand-receptor complexes, also known as cargo. Internalization of cargo is the fundamental mechanism for receptor-dependent regulation of cell membrane function, intracellular signal transduction, and neurotransmission, as well as other biological and physiological activities. However, the intrinsic mechanisms of receptor endocytosis and contemporaneous intracellular signaling are not well understood. We review emerging concepts of receptor endocytosis with concurrent intracellular signaling, using a typical example of guanylyl cyclase/natriuretic peptide receptor-A (NPRA) internalization, subcellular trafficking, and simultaneous generation of second-messenger cGMP and signaling in intact cells. We highlight the role of short-signal motifs located in the carboxyl-terminal regions of membrane receptors during their internalization and subsequent receptor trafficking in organelles that are not traditionally studied in this context, including nuclei and mitochondria. This review sheds light on the importance of future investigations of receptor endocytosis and trafficking in live cells and intact animals in vivo in physiological context.
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Affiliation(s)
- Indra Mani
- Department of Physiology, Tulane University Health Sciences Center and School of Medicine, 1430 Tulane Avenue, New Orleans, Louisiana 70112, United States
| | - Kailash N Pandey
- Department of Physiology, Tulane University Health Sciences Center and School of Medicine, 1430 Tulane Avenue, New Orleans, Louisiana 70112, United States.
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6
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Re RN. A Pathogenic Mechanism Potentially Operative in Multiple Progressive Diseases and Its Therapeutic Implications. J Clin Pharmacol 2017; 57:1507-1518. [DOI: 10.1002/jcph.997] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 07/17/2017] [Indexed: 01/07/2023]
Affiliation(s)
- Richard N. Re
- Division of Academics-Research; Ochsner Clinic Foundation; New Orleans LA USA
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7
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Ferrão FM, Cardoso LHD, Drummond HA, Li XC, Zhuo JL, Gomes DS, Lara LS, Vieyra A, Lowe J. Luminal ANG II is internalized as a complex with AT 1R/AT 2R heterodimers to target endoplasmic reticulum in LLC-PK 1 cells. Am J Physiol Renal Physiol 2017; 313:F440-F449. [PMID: 28468964 DOI: 10.1152/ajprenal.00261.2016] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 04/18/2017] [Accepted: 04/23/2017] [Indexed: 12/28/2022] Open
Abstract
ANG II has many biological effects in renal physiology, particularly in Ca2+ handling in the regulation of fluid and solute reabsorption. It involves the systemic endocrine renin-angiotensin system (RAS), but tissue and intracrine ANG II are also known. We have shown that ANG II induces heterodimerization of its AT1 and AT2 receptors (AT1R and AT2R) to stimulate sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA) activity. Thus, we investigated whether ANG II-AT1R/AT2R complex is formed and internalized, and also examined the intracellular localization of this complex to determine how its effect might be exerted on renal intracrine RAS. Living cell imaging of LLC-PK1 cells, quantification of extracellular ANG II, and use of the receptor antagonists, losartan and PD123319, showed that ANG II is internalized with AT1R/AT2R heterodimers as a complex in a microtubule-dependent and clathrin-independent manner, since colchicine-but not Pitstop2-blocked this process. This result was confirmed by an increase of β-arrestin phosphorylation after ANG II treatment, clathrin-mediated endocytosis being dependent on dephosphorylation of β-arrestin. Internalized ANG II colocalized with an endoplasmic reticulum (ER) marker and increased levels of AT1R, AT2R, and PKCα in ER-enriched membrane fractions. This novel evidence suggests the internalization of an ANG II-AT1/AT2 complex to target ER, where it might trigger intracellular Ca2+ responses.
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Affiliation(s)
- Fernanda M Ferrão
- Laboratório de Físico-Química Biológica Aída Hassón-Voloch, Instituto de Biofísica Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Luiza H D Cardoso
- Laboratório de Físico-Química Biológica Aída Hassón-Voloch, Instituto de Biofísica Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Heather A Drummond
- Department of Physiology and Biophysics and the Center for Excellence in Cardiovascular-Renal Research, University of Mississippi Medical Center, Jackson, Mississippi
| | - Xiao C Li
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Jia L Zhuo
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Dayene S Gomes
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Lucienne S Lara
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Adalberto Vieyra
- Laboratório de Físico-Química Biológica Aída Hassón-Voloch, Instituto de Biofísica Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Centro Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; and.,National Institute of Science and Technology for Regenerative Medicine, Rio de Janeiro, Brazil
| | - Jennifer Lowe
- Laboratório de Físico-Química Biológica Aída Hassón-Voloch, Instituto de Biofísica Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; .,Centro Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; and
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8
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Abstract
Heart failure and chronic renal diseases are usually progressive and only partially amenable to therapy. These disorders can be the sequelae of hypertension or worsened by hypertension. They are associated with the tissue up-regulation of multiple peptides, many of which are capable of acting within the cell interior. This article proposes that these peptides, intracrines, can form self-sustaining regulatory loops that can spread through heart or kidney, producing progressive disease. Moreover, mineralocorticoid activation seems capable of amplifying some of these peptide networks. This view suggests an expanded explanation of the pathogenesis of progressive cardiorenal disease and suggests new approaches to treatment.
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Affiliation(s)
- Richard N Re
- Ochsner Clinic Foundation, Division of Research, 1514 Jefferson Highway, New Orleans, LA 70121, USA.
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9
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An Expanded View of Progressive Cardiorenal Disorders. Am J Med Sci 2016; 351:626-33. [DOI: 10.1016/j.amjms.2016.03.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 03/17/2016] [Indexed: 11/23/2022]
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10
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A mechanism for mineralocortcoid participation in renal disease and heart failure. ACTA ACUST UNITED AC 2015; 9:586-91. [DOI: 10.1016/j.jash.2015.05.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 04/22/2015] [Accepted: 05/02/2015] [Indexed: 12/21/2022]
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Abstract
Many extracellular signaling proteins act within their cells of synthesis and/or in target cells after internalization. This type of action is called intracrine and it plays a role in diverse biological processes. The mechanisms of intracrine intracellular action are becoming clear thanks to the application of modern techniques of molecular biology. Here, progress in this area is reviewed. In particular the intracrine biology of angiotensin II is discussed.
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Affiliation(s)
- Richard N Re
- Departments of Medicine and Physiology, Tulane University School of Medicine, New Orleans, LA, USA,
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12
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A possible mechanism for the progression of chronic renal disease and congestive heart failure. ACTA ACUST UNITED AC 2014; 9:54-63. [PMID: 25539896 DOI: 10.1016/j.jash.2014.09.016] [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: 09/01/2014] [Revised: 09/11/2014] [Accepted: 09/13/2014] [Indexed: 12/15/2022]
Abstract
Chronic neurologic diseases such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis, as well as various forms of chronic renal disease and systolic congestive heart failure, are among the most common progressive degenerative disorders encountered in medicine. Each disease follows a nearly relentless course, albeit at varying rates, driven by progressive cell dysfunction and drop-out. The neurologic diseases are characterized by the progressive spread of disease-causing proteins (prion-like proteins) from cell to cell. Recent evidence indicates that cell autonomous renin angiotensin systems operate in heart and kidney, and it is known that functional intracrine proteins can also spread between cells. This then suggests that certain progressive degenerative cardiovascular disorders such as forms of chronic renal insufficiency and systolic congestive heart failure result from dysfunctional renin angiotensin system intracrine action spreading in kidney or myocardium.
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Philippou A, Maridaki M, Pneumaticos S, Koutsilieris M. The complexity of the IGF1 gene splicing, posttranslational modification and bioactivity. Mol Med 2014; 20:202-14. [PMID: 24637928 DOI: 10.2119/molmed.2014.00011] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2014] [Accepted: 03/11/2014] [Indexed: 02/06/2023] Open
Abstract
The insulinlike growth factor-I (IGF-I) is an important factor which regulates a variety of cellular responses in multiple biological systems. The IGF1 gene comprises a highly conserved sequence and contains six exons, which give rise to heterogeneous mRNA transcripts by a combination of multiple transcription initiation sites and alternative splicing. These multiple transcripts code for different precursor IGF-I polypeptides, namely the IGF-IEa, IGF-IEb and IGF-IEc isoforms in humans, which also undergo posttranslational modifications, such as proteolytic processing and glycosylation. IGF-I actions are mediated through its binding to several cell-membrane receptors and the IGF-I domain responsible for the receptor binding is the bioactive mature IGF-I peptide, which is derived after the posttranslational cleavage of the pro-IGF-I isoforms and the removal of their carboxy-terminal E-peptides (that is, the Ea, Eb and Ec). Interestingly, differential biological activities have been reported for the different IGF-I isoforms, or for their E-peptides, implying that IGF-I peptides other than the IGF-I ligand also possess bioactivity and, thus, both common and unique or complementary pathways exist for the IGF-I isoforms to promote biological effects. The multiple peptides derived from IGF-I and the differential expression of its various transcripts in different conditions and pathologies appear to be compatible with the distinct cellular responses observed to the different IGF-I peptides and with the concept of a complex and possibly isoform-specific IGF-I bioactivity. This concept is discussed in the present review, in the context of the broad range of modifications that this growth factor undergoes which might regulate its mechanism(s) of action.
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Affiliation(s)
- Anastassios Philippou
- Department of Experimental Physiology, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Maria Maridaki
- Department of Sports Medicine and Biology of Physical Activity, Faculty of Physical Education and Sport Science, National and Kapodistrian University of Athens, Athens, Greece
| | - Spiros Pneumaticos
- Third Department of Orthopaedic Surgery, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Michael Koutsilieris
- Department of Experimental Physiology, Medical School, National and Kapodistrian University of Athens, Athens, Greece
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Could Intracrine Biology Play a Role in the Pathogenesis of Transmissable Spongiform Encephalopathies Alzheimer’s Disease and Other Neurodegenerative Diseases? Am J Med Sci 2014; 347:312-20. [DOI: 10.1097/maj.0b013e3182a28af3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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15
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Weigent DA. Lymphocyte GH-axis hormones in immunity. Cell Immunol 2013; 285:118-32. [PMID: 24177252 DOI: 10.1016/j.cellimm.2013.10.003] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 10/10/2013] [Indexed: 10/26/2022]
Abstract
The production and utilization of common ligands and their receptors by cells of the immune and neuroendocrine systems constitutes a biochemical information circuit between and within the immune and neuroendocrine systems. The sharing of ligands and receptors allows the immune system to serve as the sixth sense notifying the nervous system of the presence of foreign entities. Within this framework, it is also clear that immune cell functions can be altered by neuroendocrine hormones and that cells of the immune system have the ability to produce neuroendocrine hormones. This review summarizes a part of this knowledge with particular emphasis on growth hormone (GH). The past two decades have uncovered a lot of detail about the actions of GH, acting through its receptor, at the molecular and cellular level and its influence on the immune system. The production and action of immune cell-derived GH is less well developed although its important role in immunity is also slowly emerging. Here we discuss the production of GH, GH-releasing hormone (GHRH) and insulin-like growth factor-1 (IGF-1) and their cognate receptors on cells of the immune system and their influence via endocrine/autocrine/paracrine and intracrine pathways on immune function. The intracellular mechanisms of action of immune cell-derived GH are still largely unexplored, and it is anticipated that further work in this particular area will establish an important role for this source of GH in normal physiology and in pathologic situations.
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Affiliation(s)
- Douglas A Weigent
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, 1918 University Blvd., MCLM894, Birmingham, AL 35294-0005, United States.
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16
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Prieto-Carrasquero MC, Botros FT, Kobori H, Navar LG. Collecting Duct Renin: A major player in Angiotensin II-dependent Hypertension. ACTA ACUST UNITED AC 2012; 3:96-104. [PMID: 20046983 DOI: 10.1016/j.jash.2008.11.003] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Recently, the focus of interest on the role of the renin angiotensin system in the pathophysiology of hypertension has shifted towards greater emphasis on new developments in local renin angiotensin systems in specific tissues. We have focused our recent investigations on the role of the intrarenal-intratubular RAS in hypertension. All of the components needed for angiotensin II generation are present within the various compartments in the kidney. This brief review is focused on recent evidence that inappropriate activation of renin in distal nephron segments, by acting on angiotensinogen generated in the proximal tubule cells and delivered to the distal nephron may contribute to increased distal intrarenal angiotensin II formation, sodium retention and development and progression of hypertension.
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Affiliation(s)
- Minolfa C Prieto-Carrasquero
- Department of Physiology and Tulane Renal Hypertension Center, Tulane University, School of Medicine, New Orleans, LA, 70112
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17
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Presence of urotensin-II receptors at the cell nucleus: Specific tissue distribution and hypoxia-induced modulation. Int J Biochem Cell Biol 2012; 44:639-47. [DOI: 10.1016/j.biocel.2011.12.022] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Revised: 12/14/2011] [Accepted: 12/27/2011] [Indexed: 02/07/2023]
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18
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Noncanonical intracrine action. ACTA ACUST UNITED AC 2011; 5:435-48. [DOI: 10.1016/j.jash.2011.07.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Revised: 06/09/2011] [Accepted: 07/05/2011] [Indexed: 12/24/2022]
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19
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Re RN. Lysosomal action of intracrine angiotensin II. Focus on "Intracellular angiotensin II activates rat myometrium". Am J Physiol Cell Physiol 2011; 301:C553-4. [PMID: 21734187 DOI: 10.1152/ajpcell.00232.2011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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20
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Abstract
In recent years the actions of intracellular-acting, extracellular signaling proteins/peptides (intracrines) have become increasingly defined. General principles of intracrine action have been proposed. Mitochondria represent one locus of intracrine action, and thus far, angiotensin II, transforming growth factor-beta, growth hormone, atrial natriuretic peptide, Wnt 13, stanniocalcin, other renin-angiotensin system components, and vascular endothelial-derived growth factor, among others, have been shown to be mitochondria-localizing intracrines. The implications of this mitochondrial intracrine biology are discussed.
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Affiliation(s)
- Richard N Re
- Ochsner Clinic Foundation, 1514 Jefferson Hwy., New Orleans, LA 70121, USA.
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Luheshi NM, Rothwell NJ, Brough D. Dual functionality of interleukin-1 family cytokines: implications for anti-interleukin-1 therapy. Br J Pharmacol 2010; 157:1318-29. [PMID: 19681864 PMCID: PMC2765320 DOI: 10.1111/j.1476-5381.2009.00331.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Dysregulated inflammation contributes to disease pathogenesis in both the periphery and the brain. Cytokines are coordinators of inflammation and were originally defined as secreted mediators, released from expressing cells to activate plasma membrane receptors on responsive cells. However, a group of cytokines is now recognized as having dual functionality. In addition to their extracellular effects, these cytokines act inside the nuclei of cytokine-expressing or cytokine-responsive cells. Interleukin-1 (IL-1) family cytokines are key pro-inflammatory mediators, and blockade of the IL-1 system in inflammatory diseases is an attractive therapeutic goal. All current therapies target IL-1 extracellular actions. Here we review evidence that suggests IL-1 family members have dual functionality. Several IL-1 family members have been detected inside the nuclei of IL-1-expressing or IL-1-responsive cells, and intranuclear IL-1 is reported to regulate gene transcription and mRNA splicing. However, further work is required to determine the impact of IL-1 intranuclear actions on disease pathogenesis. The intranuclear actions of IL-1 family members represent a new and potentially important area of IL-1 biology and may have implications for the future development of anti-IL-1 therapies.
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Affiliation(s)
- N M Luheshi
- Faculty of Life Sciences, University of Manchester, Manchester, UK.
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22
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Lacolley P, Safar ME, Regnault V, Frohlich ED. Angiotensin II, mechanotransduction, and pulsatile arterial hemodynamics in hypertension. Am J Physiol Heart Circ Physiol 2009; 297:H1567-75. [PMID: 19734358 DOI: 10.1152/ajpheart.00622.2009] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The aortic blood pressure curve involves two components: a steady component, the mean arterial pressure (MAP), which is dependent on cardiac output and vascular resistance, and a pulsatile component pulse pressure (PP), which is dependent on arterial stiffness and pulse wave reflections. The transduction mechanisms of MAP and PP differ markedly, involving focal adhesion kinase for MAP and oxygen free radicals for PP. Angiotensin II (ANG II) and its blockade are associated with changed vascular resistance and MAP; however, their effects on PP (peripheral and mostly central PP) have been inadequately investigated. In hypertensive rats, when compared with their normotensive controls, ANG II blockade normalizes central PP (<50 mmHg) but not MAP when the same drug dosage is used for each. In hypertensive patients, ANG II blockade reduces arterial stiffness and pulse wave reflections, but with the same reduction in MAP, there is a greater reduction in central than peripheral PP, thereby increasing carotid-brachial PP amplification. With long-term ANG II blockade, the hypertensive arteriolar hypertrophy observed at baseline is corrected in association with reduced arteriolar reflection coefficients, reduced carotid arterial attachments linking alpha(5)-integrin to its ligand fibronectin, and decreased circulating C-reactive protein. When given a normal salt diet, each of these factors contributes separately in reducing arterial stiffness and wave reflections. These responses disappear with a high-salt diet, a condition that usually involves the activation of the local vascular renin-angiotensin-aldosterone system and can be prevented by its selective blockade. Thus ANG II inhibition seems to contribute independently in reducing central PP and aortic stiffness.
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Affiliation(s)
- Patrick Lacolley
- Université Henri Poincaré, Institut National de la Santé et de la Recherche Médicale U961, Nancy, France
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23
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Re RN, Cook JL. Senescence, apoptosis, and stem cell biology: the rationale for an expanded view of intracrine action. Am J Physiol Heart Circ Physiol 2009; 297:H893-901. [PMID: 19592610 PMCID: PMC2755987 DOI: 10.1152/ajpheart.00414.2009] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2009] [Accepted: 07/02/2009] [Indexed: 12/28/2022]
Abstract
Some extracellular-signaling peptides also at times function within the intracellular space. We have termed these peptides intracrines and have argued that intracrine function is associated with a wide variety of peptides/proteins including hormones, growth factors, cytokines, enzymes, and DNA-binding proteins among others. Here we consider the possibility that intracrines participate in the related phenomena of senescence, apoptosis, and stem cell regulation of tissue biology. Based on this analysis, we also suggest that the concept of intracrine action be expanded to include possible regulatory peptide transfer via exosomes/microvesicles and possibly by nanotubes. Moreover, the process of microvesicular and nanotube transfer of peptides and other biologically relevant molecules, which we inclusively term laterality, is explored. These notions have potentially important therapeutic implications, including implications for the therapy of cardiovascular disease.
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Affiliation(s)
- Richard N Re
- Ochsner Clinic Foundation, New Orleans, LA 70121, USA.
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24
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Abstract
Hypertension and its sequelae are complex processes. Optimization of the care of the hypertensive patient requires not only attention to the regulation of arterial pressure but also attention to blunting the hypertension-related processes that lead to vascular disease. It is clear that the regulation of these processes is much more complex than previously understood. Here several new insights into the pathogenesis of hypertension-related vascular disease have been explored. While this review is not exhaustive, it does serve to point out the varied nature of the biologic processes that must be taken into account and it points to new avenues for the development of therapeutic agents.
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Affiliation(s)
- Richard N Re
- Ochsner Clinic Foundation, New Orleans, LA 70121, USA.
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25
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Sanders EJ, Harvey S. Peptide hormones as developmental growth and differentiation factors. Dev Dyn 2008; 237:1537-52. [PMID: 18498096 DOI: 10.1002/dvdy.21573] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Peptide hormones, usually considered to be endocrine factors responsible for communication between tissues remotely located from each other, are increasingly being found to be synthesized in developing tissues, where they act locally. Several hormones are now known to be produced in developing tissues that are unrelated to the endocrine gland of origin in the adult. These hormones are synthesized locally, and are active as differentiation and survival factors, before the developing adult endocrine tissue becomes functional. There is increasing evidence for paracrine and/or autocrine actions for these factors during development, thus, placing them among the conventional growth and differentiation factors. We review the evidence for the view that thyroid hormones, growth hormone, prolactin, insulin, and parathyroid hormone-related protein are developmental growth and differentiation factors.
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Affiliation(s)
- Esmond J Sanders
- Department of Physiology, University of Alberta, Edmonton, Alberta, Canada.
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26
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Abstract
Intracrine peptides and proteins participate in the regulation of adult and pleuripotential embryonic-like stem cells. Included among these factors are VEGF, dynorphin, the readthrough form of acetylcholinesterase, Oct3/4, Pdx-1, Pax-6, and high-mobility group protein B1, among others. In some cases, the establishment of intracrine feedback loops can be shown to be relevant to this regulation, consistent with previously proposed principles of intracrine action. Here the role of intracrines in stem cell regulation is reviewed, with particular attention to the intracrine regulation of cardiac stem cells. The reprogramming of cells to restore the pleuripotent phenotype and the possible role of stem/progenitor cells in neoplasia are also discussed.
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Affiliation(s)
- Richard N Re
- Ochsner Clinic Foundation, New Orleans, LA 70121, USA.
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27
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Abstract
Intracrines are extracellular signaling peptide factors that can act in the intracellular space after either internalization or retention in the cells that synthesize them. They are structurally diverse and include hormones, growth factors, enzymes, DNA-binding proteins, and other peptide moieties. We have suggested principles of intracrine action and have applied those principles to forms of cellular and tissue differentiation, hormonal responsiveness, and memory. Moreover, recent findings make clear that some currently available pharmaceuticals act via the alteration of intracrine function. Thus, the beginnings of an intracrine pharmacology are at hand and we here review principles applicable to the design of such agents. The intracrine pharmacology of the renin-angiotensin system, angiogenesis, and stem cell development is discussed.
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Affiliation(s)
- Richard N Re
- Ochsner Clinic Foundation, New Orleans, LA 70121, USA.
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28
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Chang CW, Tsai WH, Chuang WJ, Lin YS, Wu JJ, Liu CC, Tsai PJ, Lin MT. The fate of SPE B after internalization and its implication in SPEB-induced apoptosis. J Biomed Sci 2007; 14:419-27. [PMID: 17380430 DOI: 10.1007/s11373-007-9154-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2006] [Accepted: 02/01/2007] [Indexed: 10/23/2022] Open
Abstract
After streptococcal pyrogenic exotoxin B (SPE B) induces apoptosis, its fate is unknown. Using confocal time-course microscopy at 37 degrees C, we detected green fluorescence 20 min after adding FITC-SPE B. Orange fluorescence, an indication of co-localization of SPE B with lysosomes which were labeled with a red fluorescent probe, was maximal at 40 min and absent by 60 min. SPE B was co-precipitated with clathrin, which is consistent with endocytotic involvement. Western blotting assay also indicated that uptake of SPE B was maximal at 40 min and disappeared after 60 min. However, in the presence of chloroquine, a lysosome inhibitor, the uptake of SPE B was not detectable. The disappearance of TCA-precipitated FITC-SPE B was parallel to the appearance of TCA soluble FITC-SPE B; in the presence of chloroquine, however, no SPE B degradation occurred. Chloroquine increased the level of SPE B-induced apoptosis by inhibiting the degradation of SPE B. These results suggest that the internalization and degradation of SPE B in cells may be a host defense system that removes toxic substances by sacrificing the exposed cells.
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Affiliation(s)
- Chia-Wen Chang
- Institute of Basic Medical Sciences, National Cheng Kung University Medical College, Tainan, Taiwan
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29
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Nash KT, Phadke PA, Navenot JM, Hurst DR, Accavitti-Loper MA, Sztul E, Vaidya KS, Frost AR, Kappes JC, Peiper SC, Welch DR. Requirement of KISS1 secretion for multiple organ metastasis suppression and maintenance of tumor dormancy. J Natl Cancer Inst 2007; 99:309-21. [PMID: 17312308 PMCID: PMC1820615 DOI: 10.1093/jnci/djk053] [Citation(s) in RCA: 125] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND The KISS1 protein suppresses metastasis of several tumor models without blocking orthotopic tumor growth, but the mechanism remains elusive. For its role in human sexual maturation, KISS1 protein is secreted and processed to kisspeptins, which bind to the G protein-coupled receptor GPR54. We tested the hypothesis that KISS1 secretion is required for metastasis suppression via GPR54. METHODS KISS1 containing an internal FLAG epitope with (KFM) or without (KFMdeltaSS) a signal sequence was transfected into C8161.9 human melanoma cells, which do not express endogenous KISS1. Whole-cell lysates and conditioned medium from C8161.9(KFM) and C8161.9(KFMdeltaSS) cells were collected and analyzed for kisspeptins by immunoprecipitation and enzyme-linked immunosorbent assay. GPR54 levels were measured using real-time reverse transcription-polymerase chain reaction. The ability of conditioned medium from C8161.9(KFM) and C8161.9(KFMdeltaSS) cells to stimulate calcium mobilization in GPR54-expressing Chinese hamster ovary cells (CHO-G) and in C8161.9 cells was evaluated. Metastasis was monitored in athymic mice (groups of 10 per experiment) that were injected with C8161.9(KFM) or C8161.9(KFMdeltaSS) cells labeled with enhanced green fluorescent protein. Survival of mice injected with C8161.9 or C8161.9(KFM) cells was analyzed by Kaplan-Meier methods. RESULTS Full-length KFM and KFMdeltaSS were detected in whole-cell lysates of C8161.9(KFM) and C8161.9(KFMdeltaSS) cells, respectively, but kisspeptins were detected only in conditioned medium of C8161.9(KFM) cells. In vivo, C8161.9(KFM), but not C8161.9(KFMdeltaSS), cells were suppressed for metastasis to lung, eye, kidney, and bone, with corresponding differences in mouse survival (median > 120 versus 42 days). C8161.9(KFM) cells seeded mouse lungs but did not form macroscopic metastases. Conditioned medium from C8161.9(KFM), but not C8161.9(KFMdeltaSS), cells stimulated calcium mobilization in CHO-G cells. GPR54 expression was low in C8161.9 cells, which were not stimulated by conditioned medium from C8161.9(KFM) cells. CONCLUSIONS KISS1 secretion was required for multiple organ metastasis suppression and for maintenance of disseminated cells in a dormant state. The absence of GPR54 expression in C8161.9 cells (whose metastatic spread was suppressed by KFM) suggests that metastasis suppression is not mediated through this receptor. The results imply the existence of another KISS1 receptor and/or paracrine signaling. The findings raise the possibility that soluble KISS1, kisspeptins, or mimetics could be used to maintain tumor dormancy, rendering treatment of already disseminated tumor cells (i.e., micrometastases) a legitimate target.
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Affiliation(s)
- Kevin T Nash
- Department of Pathology, University of Alabama, Birmingham, AL, USA
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30
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Potential therapeutic implications of intracrine angiogenesis. Med Hypotheses 2007; 69:414-21. [PMID: 17320306 DOI: 10.1016/j.mehy.2006.10.065] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2006] [Accepted: 10/23/2006] [Indexed: 01/19/2023]
Abstract
Angiogenesis, in most cases, is a requirement for tumor growth beyond a diameter of a few millimeters and is, therefore, a major target for cancer therapy. The intracellular actions of certain extracellular signaling proteins (intracrines) have been reported, and it is clear that intracrines such as vascular endothelial growth factor, basic fibroblast growth factor, angiogenin, angiotensin, and endothelin, among others, are involved in angiogenesis. We have proposed that intracrine networks play an important role in angiogenesis, and have suggested that very similar intracrine networks exist in some tumor cells. These notions have implications for the development of anti-angiogenesis therapies because they suggest that the inhibition of intracellular intracrine trafficking pathways may be an effective therapeutic target. Here the participation and regulation of intracrines in angiogenesis is explored, as are the actions of various anti-angiogenic factors.
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31
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Mukdsi JH, De Paul AL, Petiti JP, Gutiérrez S, Aoki A, Torres AI. Pattern of FGF-2 isoform expression correlated with its biological action in experimental prolactinomas. Acta Neuropathol 2006; 112:491-501. [PMID: 16823503 DOI: 10.1007/s00401-006-0101-9] [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] [Received: 04/26/2006] [Revised: 06/08/2006] [Accepted: 06/08/2006] [Indexed: 11/28/2022]
Abstract
Fibroblast growth factor-2 (FGF-2) synthesized in the pituitary is involved in the formation and progression of pituitary tumors. The aim of this study was to analyze the pattern expression of two FGF-2 isoforms at different subcellular levels and to determine its correlation with prolactinoma development. Estrogen administration to male rats for 7, 20, and 60 days generated pituitary tumors, with lactotrophs being the prevalent cell type. Ultrastructural immunolabeling showed FGF-2 in the cytosolic and nuclear compartments of somatotrophs, lactotrophs and gonadotrophs, as well as in folliculo-stellate cells of normal rats. Estrogen stimulation increased FGF-2 immunoreactivity in various tumors and enhanced the expression of two FGF-2 isoforms, 18 and 22 kDa, as quantified by western blot. The 18 kDa isoform observed in cytosol extracts reached the highest levels after 60 days of hormonal stimulation and this was related to lactotroph proliferation. However, the 22 kDa FGF-2 isoform was only detected in the nuclear compartment and achieved the maximum expression at 7 days of estrogen treatment, without any correlation with lactotroph proliferation. These results suggest that the 18 kDa FGF-2 may play a role in the modulation of lactotroph proliferation in prolactinomas induced by estrogen. The overproduction of both FGF-2 isoforms appears to be implicated in autocrine-paracrine-intracrine mitogenic loops; this FGF-2 activity could lead to uncontrolled cell growth, angiogenesis, and tumor formation.
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Affiliation(s)
- Jorge H Mukdsi
- Centro de Microscopía Electrónica, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Haya de la Torre, Pabellón de Biología Celular, Ciudad Universitaria, X5000, HRA, Córdoba, Argentina
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32
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Abstract
Angiogenesis, the generation of new blood vessels from pre-existing vessels, is an integral component of wound healing, responses to inflammation and other physiologic processes. It is also an essential part of tumor growth; in the absence of new vessel formation, tumors cannot expand beyond a small volume. Although much is known about angiogenesis and its regulation, there is no overall theory that describes or explains this process. It is here suggested that the intracrine hypothesis, which ascribes to certain extracellular signaling peptides (whether hormones, growth factors, DNA-binding proteins or enzymes) a role in both intracellular biology and extracellular signaling, can contribute to a more general understanding of angiogenesis. Intracrine factors participate in angiogenesis in the following ways: (1) they can act within the cells that synthesized them (type I intracrine action), (2) they can be secreted and then taken up by their cell of synthesis to act intracellularly (type II intracrine action ), or (3) they can be secreted and internalized by a distant target cell (type III intracrine action). The parallels between the intracrine growth factor mechanisms cancer cells employ in stimulating their own growth and the mechanisms operative in endothelial cell proliferation during angiogenesis ("intracrine reciprocity") are discussed. Collectively, these explorations lead to testable hypotheses regarding the regulation of normal and pathological angiogenesis, and point to similarities between tumor-induced angiogenesis and tissue differentiation.
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Affiliation(s)
- Richard N Re
- Research Division, Ochsner Clinic Foundation, New Orleans, LA 70121, USA.
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33
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Mukdsi JH, De Paul AL, Gutiérrez S, Roth FD, Aoki A, Torres AI. Subcellular localisation of VEGF in different pituitary cells. Changes of its expression in oestrogen induced prolactinomas. J Mol Histol 2006; 36:447-54. [PMID: 16733790 DOI: 10.1007/s10735-005-9012-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2005] [Accepted: 11/23/2005] [Indexed: 01/06/2023]
Abstract
Vascular endothelial growth factor (VEGF) is an important angiogenic factor in the pituitary gland. The objective of this study was to unveil the VEGF subcellular localisation in different pituitary cell types and to evaluate changes in its expression at different time intervals after oestrogen stimulation. A relevant feature demonstrated was the identification of this cytokine in the nucleus and cytoplasm of lactotrophs, somatotrophs and gonadotrophs, as well as in follicle-stellate cells of male rats. Oestrogen treatment increased the number of VEGF immunopositive cells and its expression detected differentially by western blot in both nucleus and cytoplasm of pituitary cells when compared to the control. At ultrastructural level VEGF appeared associated with nucleolus and euchromatin involving a possible internal autocrine loop. In lactotrophs, the predominant cell of the tumour, VEGF was immunodetected in RER, Golgi complex, and vesicular organelles, supporting further the association with an auto-paracrine effect exerted by VEGF. The nucleus/cytoplasm ratio of VEGF revealed a prevalent accumulation of VEGF in the cytoplasm. The presence of VEGF in the nucleus may probably be associated with a translocation to this cell compartment. This study demonstrated a cytoplasmic and nuclear immunolocalisation of VEGF in normal and tumoural adenohypophyseal cells. In the course of prolactinoma development, the oestrogen stimulated VEGF expression in tumoural cells, promoting a vascular adaptation which contributes to growth and progression of the tumour.
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Affiliation(s)
- Jorge Humberto Mukdsi
- Centro de Microscopía Electrónica, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Córdoba, Argentina
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Shirani J, Narula J, Eckelman WC, Dilsizian V. Novel Imaging Strategies for Predicting Remodeling and Evolution of Heart Failure: Targeting the Renin-angiotensin System. Heart Fail Clin 2006; 2:231-47. [PMID: 17386892 DOI: 10.1016/j.hfc.2006.05.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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35
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Lavoie JL, Liu X, Bianco RA, Beltz TG, Johnson AK, Sigmund CD. Evidence supporting a functional role for intracellular renin in the brain. Hypertension 2006; 47:461-6. [PMID: 16446393 DOI: 10.1161/01.hyp.0000203308.52919.dc] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The brain renin-angiotensin system is implicated in the regulation of blood pressure (BP) and fluid homeostasis. Recent studies reveal that 2 forms of renin are expressed in the brain of rodents and humans: secreted prorenin and a nonsecreted intracellular form of active renin (icREN). Although the intracellular action of renin has long been postulated, no data supporting its role in BP regulation has been reported. Therefore, we directly evaluated whether this form of renin has physiological implications for BP regulation by characterizing transgenic mice expressing human icREN driven by the glial fibrillary acidic protein (GFAP) promoter and comparing it with similar mice expressing the secreted form of renin. GFAP-icREN mice express hREN primarily in the brain and at the same level of expression as GFAP-secreted prorenin. Unlike the secreted form, which can be detected in cerebrospinal fluid, no human renin could be detected in the cerebrospinal fluid of GFAP-icREN mice. GFAP-icREN mice were then bred with transgenic mice expressing human angiotensinogen, also driven by the GFAP promoter. Double-transgenic mice expressing either the intracellular renin (2.0+/-0.12 mL/10 g/day) or secreted renin (2.8+/-0.3 mL/10 g/day) exhibited an increase in drinking volume compared with nontransgenic littermates (1.5+/-0.1 mL/10 g/day). Both models exhibited an increase in mean arterial pressure (137+/-5 and 133+/-8 mm Hg, respectively) compared with control littermates (115+/-3 mm Hg), which could be rapidly reduced after ICV injection of losartan. These data support the concept of an intracellular form of renin in the brain, which may provoke functional changes in fluid homeostasis and BP regulation.
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Affiliation(s)
- Julie L Lavoie
- Department of Internal Medicine, University of Iowa, Iowa City, Iowa, USA
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36
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Re RN, Cook JL. The intracrine hypothesis: an update. ACTA ACUST UNITED AC 2005; 133:1-9. [PMID: 16226324 DOI: 10.1016/j.regpep.2005.09.012] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2005] [Accepted: 09/08/2005] [Indexed: 01/17/2023]
Abstract
The intracellular actions of peptide hormones, growth factors, as well as of extracellular-signaling enzymes and DNA-binding proteins, either within target cells or within their cells of synthesis has been called intracrine action. Although these intracrine moieties are structurally diverse, they share certain characteristics of synthesis and function. This has given rise to the development of a theory of intracrine action which permits testable predictions to be made regarding the functioning of these peptides/proteins. Here the intracrine hypothesis is briefly described and then recent experimental findings which bear on predictions made earlier on the basis of the theory are discussed. These findings provide new support for the intracrine hypothesis.
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Affiliation(s)
- Richard N Re
- Research Division, Ochsner Clinic Foundation, 1516 Jefferson Highway, New Orleans, LA 70121, USA.
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Abstract
Hypertension remains one of the largest human health problems, because hypertensive patients carry increased risk for ischemic heart disease, stroke, atherosclerosis, and renal failure. The renin-angiotensin system (RAS) has been intensively investigated for more than 100 years because it is a powerful regulator of blood pressure, and the antihypertensive benefits of RAS inhibitors are very clear. Despite a wealth of clinical and basic studies, the precise mechanisms by which the RAS regulates blood pressure remains incomplete. In this chapter, we review data demonstrating the existence and function of intrinsic tissue RAS, with a primary focus on the brain.
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Affiliation(s)
- Koji Sakai
- Departments of Internal Medicine and Physiology & Biophysics, 3181B Medical Education and Biomedical Research Facility, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 52242 Iowa City, IA USA
| | - Curt D. Sigmund
- Departments of Internal Medicine and Physiology & Biophysics, 3181B Medical Education and Biomedical Research Facility, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, 52242 Iowa City, IA USA
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Zeh HJ, Lotze MT. Addicted to death: invasive cancer and the immune response to unscheduled cell death. J Immunother 2005; 28:1-9. [PMID: 15614039 DOI: 10.1097/00002371-200501000-00001] [Citation(s) in RCA: 122] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The development of an invasive cancer involves a progressive switch from predominantly apoptotic (scheduled) to necrotic (unscheduled) tumor cell death. This switch is associated with chronic and increasing release of intracellular factors that in turn promote reactive angiogenesis and stromal proliferation and mediates the disordered tumor microenvironment associated with local immune suppression. The authors review the relevant immunobiology of these factors, including the nuclear protein HMGB1; the products of purine metabolism (uric acid, ATP, and adenosine); the S100 family members; and the heat shock proteins, which we believe drive futile cycles of cell death followed by reparative cell growth. The authors also present a novel and provocative hypothesis that suggests that most of the derangements that we associate with progression of cancer and the associated immunologic consequences can indeed be ascribed to the consequences of disordered tumor cell death rather than cell growth. Thus the fundamental defect in invasive human cancers, in the authors' view, is not one of cell growth but rather one of disordered cell death, resulting in turn in a tumor microenvironment that encourages tumor growth, progression, and local immunosuppression, a condition the authors have termed "addicted to death." This new understanding could inform and drive the development of more effective biologic therapies for patients with cancer.
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Affiliation(s)
- Herbert J Zeh
- University of Pittsburgh School of Medicine Institute, Room 411, 300 Technology Drive, Pittsburgh, PA 15219, USA
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39
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Abstract
Urotensin-II (U-II) is a cyclic 11-amino acid peptide known as a potent mammalian vasoconstrictor. To study some purported intracellular actions of U-II, masked analogs of this peptide, becoming biologically active only upon UV exposure, were developed. Those analogs described as "caged" were derivatized with a photolabile 4,5-dimethoxynitrobenzyl group on the side chain of Lys-8 or Tyr-9. Both caged analogs of U-II showed a major decrease in their affinity towards the UT receptor. Nevertheless, upon UV irradiation, the native and biologically active U-II peptide was recovered. Thus, this work describes the development of new "caged" U-II derivatives and demonstrates that vasoactivity of U-II can be controlled by masking and unmasking two key residues.
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Affiliation(s)
- Steve Bourgault
- Université du Québec, Laboratoire d'études moléculaires et pharmacologiques des peptides, INRS--Institut Armand-Frappier, Institut National de la Recherche Scientifique, 245 boul. Hymus, Pointe-Claire (Montréal), Que. Canada H9R 1G6
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40
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Larrinaga G, Callado LF, Agirregoitia N, Varona A, Gil J. Subcellular distribution of membrane-bound aminopeptidases in the human and rat brain. Neurosci Lett 2005; 383:136-40. [PMID: 15936526 DOI: 10.1016/j.neulet.2005.03.061] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2005] [Revised: 03/10/2005] [Accepted: 03/30/2005] [Indexed: 11/26/2022]
Abstract
We evaluated the subcellular distribution of four membrane-bound aminopeptidases in the human and rat brain cortex. The particulate enzymes under study--puromycin-sensitive aminopeptidase (PSA), aminopeptidase N (APN), pyroglutamyl-peptidase I (PG I) and aspartyl-aminopeptidase (Asp-AP)--were fluorometrically measured using beta-naphthylamide derivatives. Membrane-bound aminopeptidase activity was found in all the studied subcellular fractions (myelinic, synaptosomal, mitochondrial, microsomal and nuclear fractions), although not homogenously. Human PSA showed highest activity in the microsomal fraction. APN was significantly higher in the nuclear fraction of both species, while PG I showed highest activity in the synaptosomal and myelinic fractions of the human and rat brain. The present results suggest that in addition to inactivating neuropeptides at the synaptic cleft, these enzymes may participate in other physiological processes. Moreover, these peptidases may play specific roles depending on their activity levels at the different subcellular structures where they are localized.
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Affiliation(s)
- Gorka Larrinaga
- Department of Nursing I, University of the Basque Country, Bilbao, Bizkaia, Spain.
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41
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Abstract
Since its discovery by Erspamer in the 1930s and identification by Page in the 1950s, 5-HT (5-hydroxytryptamine; serotonin) has been an elusive candidate as a substance that plays a role in the disease of high blood pressure, also known as hypertension. In both animal and human hypertension, arterial contraction to 5-HT is profoundly enhanced. Additionally, 5-HT is a vascular smooth muscle cell mitogen. Because both increased arterial contractility and smooth muscle growth contribute to the disease of hypertension, it is logical to believe that 5-HT is a potential cause of disease, and thus a foe. However, decades of research have produced conflicting results as to the potential role of 5-HT in hypertension. This review will discuss historical findings which both support and refute the involvement of 5-HT in hypertension, and pose some new questions that may reveal novel ways for 5-HT to modify vascular control of blood pressure.
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Affiliation(s)
- Stephanie W Watts
- Department of Pharmacology and Toxicology, B445 Life Sciences Building, Michigan State University, East Lansing, MI 48824-1317, USA.
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42
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Shirani J, Loredo ML, Eckelman WC, Jagoda EM, Dilsizian V. Imaging the renin-angiotensin-aldosterone system in the heart. Curr Heart Fail Rep 2005; 2:78-86. [PMID: 16036055 DOI: 10.1007/s11897-005-0013-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The influence of the renin-angiotensin system (RAS) is recognized in cardiac and vascular injury. An extrinsic RAS has been known for decades, and an equally important intrinsic RAS has been discovered recently. The latter leads to pathologic tissue alterations in the absence of systemic stimuli and may be the main source of local tissue effects of RAS. A new radiotracer fluorobenzoyl-lisinopril was synthesized by radiolabeling benzoic acid active ester with 18F and reacting that with the epsilon-amino group of lisinopril. The presence of angiotensin-converting enzyme (ACE) activity and angiotensin II receptors was examined in relation to myocardial fibrosis. This tissue-specific radioligand represents the first study of ACE in the human heart. This article presents preliminary data on imaging the RAS in the human cardiac tissue and discusses the potential for clinical application of these imaging techniques to human patients.
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Affiliation(s)
- Jamshid Shirani
- Geisinger Medical Center, Division of Cardiology, 100 North Academy Avenue, Danville, PA 17822, USA.
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43
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Lotze MT, Tracey KJ. High-mobility group box 1 protein (HMGB1): nuclear weapon in the immune arsenal. Nat Rev Immunol 2005; 5:331-42. [PMID: 15803152 DOI: 10.1038/nri1594] [Citation(s) in RCA: 1881] [Impact Index Per Article: 99.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
High-mobility group box 1 protein (HMGB1), which previously was thought to function only as a nuclear factor that enhances transcription, was recently discovered to be a crucial cytokine that mediates the response to infection, injury and inflammation. These observations have led to the emergence of a new field in immunology that is focused on understanding the mechanisms of HMGB1 release, its biological activities and its pathological effects in sepsis, arthritis, cancer and other diseases. Here, we discuss these features of HMGB1 and summarize recent advances that have led to the preclinical development of therapeutics that modulate HMGB1 release and activity.
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Affiliation(s)
- Michael T Lotze
- University of Pittsburgh School of Medicine, Room 411, 300 Technology Drive, Pittsburgh, Pennsylvania 15219, USA.
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44
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Scharpfenecker M, Fiedler U, Reiss Y, Augustin HG. The Tie-2 ligand angiopoietin-2 destabilizes quiescent endothelium through an internal autocrine loop mechanism. J Cell Sci 2005; 118:771-80. [PMID: 15687104 DOI: 10.1242/jcs.01653] [Citation(s) in RCA: 292] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The angiopoietins Ang-1 and Ang-2 have been identified as ligands of the endothelial receptor tyrosine kinase Tie-2, which controls vascular assembly and endothelial quiescence. The largely complementary phenotypes of Ang-1-deficient mice and Ang-2-overexpressing mice have led to an antagonistic model in which Ang-1 acts as Tie-2-activating agonist and Ang-2 acts as a Tie-2-inhibiting antagonist. To date, no mechanistic equivalent of the antagonistic Ang-1/Ang-2 model has been established and the mechanisms of Ang-2 function in particular remain mysterious. We have studied the effector functions of Ang-1 and Ang-2 on quiescent endothelial cells using a three-dimensional co-culture model of endothelial cells and smooth-muscle cells. Endothelial-cell monolayer integrity in this model is dependent on Tie-2 signaling, as evidenced by detaching endothelial cells following exposure to the small molecular weight Tie-2 inhibitor A-422885.66, which cannot be overcome by exogenous Ang-1. Accordingly, exogenous Ang-2 rapidly destabilizes the endothelial layer, which can be observed within 30-60 minutes and leads to prominent endothelial-cell detachment within 4 hours. Exogenous Ang-2-mediated endothelial-cell detachment can be rescued by Ang-1, soluble Tie-2 and vascular endothelial growth factor. Similar findings were obtained in an umbilical-vein explant model. Ang-2 is mainly produced by endothelial cells and therefore acts primarily in an autocrine manner. Thus, stimulated release of endogenous Ang-2 or overexpression of Ang-2 in endothelial cells perturbs co-culture spheroid integrity, which can be rescued by exogenous Ang-1 and vascular endothelial growth factor. However, autocrine Ang-2-mediated endothelial-cell detachment cannot be blocked by soluble Tie-2. Taken together, the data demonstrate for the first time the antagonistic Ang-1/Ang-2 concept in a defined cellular model and identify Ang-2 as a rapidly acting autocrine regulator of the endothelium that acts through an internal autocrine loop mechanism.
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Affiliation(s)
- Marion Scharpfenecker
- Department of Vascular Biology and Angiogenesis Research, Tumor Biology Center, 79106 Freiburg, Germany
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45
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Larrinaga G, Gil J, Meana JJ, Ruiz F, Callado LF, Irazusta J. Aminopeptidase activity in the postmortem brain of human heroin addicts. Neurochem Int 2005; 46:213-9. [PMID: 15670637 DOI: 10.1016/j.neuint.2004.10.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2004] [Accepted: 10/07/2004] [Indexed: 10/26/2022]
Abstract
Several studies have reported that the chronic administration of opioids induces changes in the biosynthesis of endogenous opioid peptides or their precursors in specific brain regions of the adult central nervous system. However, little is known about the catabolic regulation of opioid peptides and its contribution to neuroadaptative changes underlying drug addiction. In the present study, we have analyzed the activity of two enkephalin-degrading enzymes (puromycin-sensitive aminopeptidase or PSA and aminopeptidase N or APN) and two functionally different, soluble aminopeptidases (aminopeptidase B and aspartyl-aminopeptidase) in postmortem samples of prefrontal cortex and caudate nucleus of eight human heroin addict brains and eight matched-controls. Enzyme activities were fluorimetrically measured using beta-naphthylamide derivatives. An increase in the activity of soluble PSA in the prefrontal cortex of heroin abusers was observed (heroin addict group: 51,452+/-3892 UAP/mg protein versus control group: 42,003+/-2597 UAP/mg protein; P<0.05), while the activity of the other peptidases in both brain regions remained unaltered. This result agrees with previous findings in morphine-tolerant rats, and indicates that soluble PSA may be involved in neurobiological processes which underlie heroin addiction.
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Affiliation(s)
- G Larrinaga
- Department of Nursing I, University of the Basque Country, Leioa, P.O. Box 699, E-48940 Bilbao, Bizkaia, Spain.
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46
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Abstract
PURPOSE OF REVIEW Recent studies have reported that intrarenal angiotensin II content and angiotensin II concentrations in the proximal tubular fluid and renal interstitial fluid are much greater than the circulating angiotensin II levels. These high intrarenal angiotensin II levels are responsible for regulating renal hemodynamics and tubular transport. RECENT FINDINGS Intrarenal angiotensin II levels have been assessed from total tissue contents as well as renal interstitial fluid and proximal tubular fluid concentrations. Total tissue contents expressed per gram of tissue weight are greater than plasma angiotensin II concentrations; tubular fluid concentrations and renal interstitial fluid concentrations are even greater in the range of 3-10 pmoles/ml. In hypertensive states, there is also an increased intracellular accumulation of angiotensin II mediated by angiotensin type 1 receptor-dependent endocytosis. The high intrarenal angiotensin II levels are also caused by the presence of angiotensinogen messenger RNA and protein in the proximal tubule cells. Furthermore, there is positive amplification by which increases in circulating angiotensin II stimulate increased production and secretion of angiotensinogen, which is also manifested as an increased urinary excretion rate. SUMMARY The ability of the kidney to generate high intratubular and interstitial concentrations allows the kidney to regulate intrarenal levels in accord with the homeostatic needs for the regulation of renal hemodynamics and tubular reabsorption and the regulation of sodium balance. When inappropriately stimulated, high intrarenal angiotensin II levels contribute to excessive salt and water retention, the development of hypertension, and long-term proliferative effects leading to renal injury.
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Affiliation(s)
- L Gabriel Navar
- Department of Physiology and Hypertension, Renal Center of Excellence, Tulane University Health Scences Center, New Orleans, Louisiana 70112, USA.
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47
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Affiliation(s)
- L Gabriel Navar
- Tulane University School of Medicine, New Orleans, Louisiana 70112, USA.
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48
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Sherrod M, Liu X, Zhang X, Sigmund CD. Nuclear localization of angiotensinogen in astrocytes. Am J Physiol Regul Integr Comp Physiol 2004; 288:R539-46. [PMID: 15388495 DOI: 10.1152/ajpregu.00594.2004] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
In the brain, angiotensinogen (AGT) is primarily expressed in astrocytes; brain ANG II derived from locally produced AGT has been shown to influence blood pressure. To better understand the molecular basis of AGT expression in the brain, we identified a human astrocytoma cell line, CCF-STTG1, that expresses endogenous AGT mRNA and produces AGT protein. Studies examining CCF-STTG1 cell AGT after N- and O-glycosidase suggest that AGT may not be posttranslationally modified by glycosylation in these cells as it is in plasma. Small amounts of AGT (5% of HepG2) were detected in the culture medium, suggesting a low rate of AGT secretion. Immunocytochemical examination of AGT in CCF-STTG1 cells revealed mainly nuclear localization. Although this has not been previously reported, it is consistent with nuclear localization of other serpin family members. To examine this further, we generated a fusion protein consisting of green fluorescent protein (GFP) and human AGT and examined subcellular localization by confocal microscopy after confirming expression of the fusion protein by Western blot. In CCF-STTG1 cells, a control GFP construct lacking AGT was mainly localized in the cytoplasm, whereas the GFP-AGT fusion protein was primarily localized in the nucleus. To map the location of a potential nuclear localization signal, overlapping 500-bp fragments of human AGT cDNA were fused in frame downstream of GFP. Although four of the fusion proteins exhibited either perinuclear or cytoplasmic localization, one fusion protein encoding the COOH terminus of AGT was localized in the nucleus. Importantly, nuclear localization of human AGT was confirmed in primary cultures of glial cells isolated from transgenic mice expressing the human AGT under the control of its own endogenous promoter. Our results suggest that AGT may have a novel intracellular role in the brain apart from its predicted endocrine function.
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Affiliation(s)
- Mikhiela Sherrod
- Genetics Graduate Program, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242, USA
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49
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Lavoie JL, Cassell MD, Gross KW, Sigmund CD. Localization of renin expressing cells in the brain, by use of a REN-eGFP transgenic model. Physiol Genomics 2004; 16:240-6. [PMID: 14625376 DOI: 10.1152/physiolgenomics.00131.2003] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Immunoreactive renin has been reported in the hypothalamus and cerebellar cortex in the rodent brain and in neurons in all areas of the human brain. Despite these observations and the clear documentation of the expression of the other renin-angiotensin system genes in the brain, the notion that renin is endogenously expressed in the brain remains very controversial and undefined. This controversy no doubt arises because the level of renin expression in the brain is below the detection threshold of most standard assays. A transgenic mouse expressing enhanced green fluorescence protein (eGFP) under the control of the mouse renin promoter was recently reported. This model expresses eGFP in the kidney, which responds appropriately to both developmental and physiological stimuli. We therefore used eGFP as a sensitive marker to identify renin-expressing cells in the brain. We identified eGFP-containing cells in specific areas of the brain, including cerebellum, hippocampus, dorsal motor nucleus of the vagus, inferior olivary nucleus, reticular formation, rostral ventrolateral medulla, central nucleus of the amygdala, lateral parabrachial nucleus, mesencephalic trigeminal nucleus, bed nucleus of stria terminalis, and subfornical organ. By colabeling with neuron- or glia (astrocytes or oligodendrocytes)-specific antisera, we have determined the eGFP-positive cells to be mainly neuronal. These findings therefore strongly support the primary expression of renin mRNA in the brain in regions controlling cardiovascular function.
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Affiliation(s)
- Julie L Lavoie
- Department of Internal Medicine, University of Iowa, Iowa City, Iowa 52242, USA
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50
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Gutzman JH, Miller KK, Schuler LA. Endogenous human prolactin and not exogenous human prolactin induces estrogen receptor alpha and prolactin receptor expression and increases estrogen responsiveness in breast cancer cells. J Steroid Biochem Mol Biol 2004; 88:69-77. [PMID: 15026085 DOI: 10.1016/j.jsbmb.2003.10.008] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2003] [Accepted: 10/27/2003] [Indexed: 01/12/2023]
Abstract
Prolactin (PRL) and estrogen act synergistically to increase mammary gland growth, development, and differentiation. Based on their roles in the normal gland, these hormones have been studied to determine their interactions in the development and progression of breast cancer. However, most studies have evaluated only endocrine PRL and did not take into account the recent discovery that PRL is synthesized by human mammary cells, permitting autocrine/paracrine activity. To examine the effects of this endogenous PRL, we engineered MCF7 cells to inducibly overexpress human prolactin (hPRL). Using this Tet-On MCF7hPRL cell line, we studied effects on cell growth, PRLR, ER alpha, and PgR levels, and estrogen target genes. Induced endogenous hPRL, but not exogenous hPRL, increased ER alpha levels as well as estrogen responsiveness in these cells, suggesting that effects on breast cancer development and progression by estrogen may be amplified by cross-regulation of ER alpha levels by endogenous hPRL. The long PRLR isoform was also upregulated by endogenous, but not exogenous PRL. This model will allow investigation of endogenous hPRL in mammary epithelial cells and will enable further dissection of PRL effects on other hormone signaling pathways to determine the role of PRL in breast cancer.
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Affiliation(s)
- Jennifer H Gutzman
- Department of Comparative Biosciences, 2015 Linden Drive, University of Wisconsin-Madison, Madison, WI 53706, USA
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