51
|
Aldosterone antisecretagogue and antihypertensive actions of adrenomedullin in patients with primary aldosteronism. Hypertens Res 2010; 33:374-9. [DOI: 10.1038/hr.2010.8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
52
|
Ma W, Dumont Y, Vercauteren F, Quirion R. Lipopolysaccharide induces calcitonin gene-related peptide in the RAW264.7 macrophage cell line. Immunology 2010; 130:399-409. [PMID: 20141542 DOI: 10.1111/j.1365-2567.2009.03239.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
SUMMARY Calcitonin gene-related peptide (CGRP) is widely distributed and plays important roles in a wide array of biological functions. It is enriched in primary sensory neurons and hence involved in nociception and neurogenic inflammation. Recent studies have shown that CGRP can be produced by immune cells such as monocytes/macrophages following inflammatory stimulation, suggesting a role in innate immunity. However, it is unclear how CGRP is up-regulated in macrophages and if it plays a role in macrophage functions such as the production of cytokines and chemokines. Using enzyme-linked immunosorbent assay (ELISA) and multiplex ELISA, lipopolysaccharide (LPS) was found to induce CGRP in the RAW 264.7 macrophage cell line. LPS-induced inflammatory mediators such as nerve growth factor (NGF), interleukin-1beta (IL-1beta), IL-6, prostaglandin E(2) (PGE(2)) and nuclear factor-kappaB (NF-kappaB) signalling are involved in inducing CGRP, whereas the NGF receptor trkA and CGRP receptor signalling pathways are unexpectedly involved in suppressing LPS-induced CGRP, which leads to the fine-tune regulation of CGRP release. Exogenous CGRP and CGRP receptor antagonists, in a concentration-dependent manner, stimulated, inhibited or had no effect on basal or LPS-induced release of monocyte chemoattractant protein-1, IL-1beta, IL-6, tumour necrosis factor-alpha and IL-10 in RAW macrophages. The ligand-concentration-dependent regulation of the production of inflammatory mediators by CGRP receptor signalling is a novel mechanism underlying the stimulating and suppressing role of CGRP in immune and inflammatory responses. Together, our data suggest that monocytes/macrophages are an important source of CGRP. Inflammation-induced CGRP has a positive or negative reciprocal effect on the production of other pro- and anti-inflammatory mediators. Thereby CGRP plays both facilitating and suppressing roles in immune and inflammatory responses.
Collapse
Affiliation(s)
- Weiya Ma
- Douglas Mental Health University Institute, McGill University, Montreal, QC, Canada.
| | | | | | | |
Collapse
|
53
|
Hemodynamic and hormonal effects of exogenous adrenomedullin administration in humans and relationship to insulin resistance. Hypertens Res 2010; 33:314-9. [DOI: 10.1038/hr.2009.236] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
54
|
Nørregaard R, Bødker T, Jensen BL, Stødkilde L, Nielsen S, Frøkiær J. Increased renal adrenomedullin expression in rats with ureteral obstruction. Am J Physiol Regul Integr Comp Physiol 2009; 296:R185-92. [DOI: 10.1152/ajpregu.00170.2008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Ureteral obstruction is characterized by decreased renal blood flow that is associated with hypoxia within the kidney. Adrenomedullin (AM) is a peptide hormone with tissue-protective capacity that is stimulated through hypoxia. We tested the hypothesis that ureteral obstruction stimulates expression of AM and hypoxia-inducible factor-1 (HIF-1α) in kidneys. Rats were exposed to bilateral ureteral obstruction (BUO) for 2, 6, 12, and 24 h or sham operation and compared with unilateral obstruction (UUO). AM mRNA expression was measured by quantitative PCR in cortex and outer medulla (C+OM) and inner medulla (IM). AM and HIF-1α protein abundance and localization were determined in rats subjected to 24-h BUO. AM mRNA expression in C+OM increased significantly after 12-h BUO and further increased after 24 h. In IM, AM mRNA expression increased significantly in response to BUO for 6 h and further increased after 24 h. AM peptide abundance was enhanced in C+OM and IM after 24-h BUO. Immunohistochemical labeling of kidneys showed a wider distribution and more intense AM signal in 24-h BUO compared with Sham. In UUO rats, AM mRNA expression increased significantly in IM of the obstructed kidney compared with nonobstructed and Sham kidney whereas AM peptide increased in IM compared with Sham. HIF-1α protein abundance increased significantly in IM after 24-h BUO compared with Sham and HIF-1α immunoreactive protein colocalized with AM. In summary, AM and HIF-1α expression increases in response to ureteral obstruction in agreement with expected oxygen gradients. Hypoxia acting through HIF-1α accumulation may be an important pathway for the renal response to ureteral obstruction.
Collapse
|
55
|
Okura T, Marutsuka K, Hamada H, Sekimoto T, Fukushima T, Asada Y, Kitamura K, Chosa E. Therapeutic efficacy of intra-articular adrenomedullin injection in antigen-induced arthritis in rabbits. Arthritis Res Ther 2008; 10:R133. [PMID: 19014513 PMCID: PMC2656235 DOI: 10.1186/ar2550] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2008] [Revised: 10/15/2008] [Accepted: 11/13/2008] [Indexed: 12/25/2022] Open
Abstract
Introduction Adrenomedullin is a potent vasodilatory and hypotensive peptide as well as an endogenous immunomodulatory factor with predominantly anti-inflammatory effects. The purpose of the present study was to evaluate the therapeutic effects of adrenomedullin in rabbits with antigen-induced arthritis, an experimental model of rheumatoid arthritis. Methods Following the induction of arthritis in both knee joints by ovalbumin injection into the joint spaces of pre-immunized rabbits, increasing daily doses of adrenomedullin were injected into the knee joint spaces or saline was injected into the contralateral knee joint spaces as the control. For time-course experiments, adrenomedullin and saline were injected into the knee joint spaces daily for 7 days and 20 days. The degree of joint swelling and the histological change in the knee joints injected with adrenomedullin were compared with the control knee joints. Histological evaluation of the infrapatellar fat pads and synovial tissue was performed. TNFα, IL-6, vascular endothelial growth factor and transforming growth factor-beta mRNA levels in the synovial tissue were measured using real-time quantitative PCR. Results Daily injections of adrenomedullin into the knee joint spaces of rabbits with antigen-induced arthritis decreased joint swelling. Histological examination revealed that adrenomedullin reduced edematous changes and the infiltration of inflammatory cells in the synovial tissues. Analysis of mRNA levels showed that adrenomedullin significantly reduced TNFα mRNA expression by 21% to 49% in a dose-dependent manner, and dose-dependently increased IL-6 mRNA expression by 45% to 121%. Conclusions These results suggest that daily injections of adrenomedullin into the knee joint spaces of rabbits with antigen-induced arthritis ameliorated the inflammatory response in arthritic joints. Adrenomedullin may thus be useful as a treatment for rheumatoid arthritis; however, the effect of adrenomedullin on IL-6 production in the synovial tissue may be an undesirable adverse effect in rheumatoid arthritis therapy.
Collapse
Affiliation(s)
- Toshiyuki Okura
- Department of Medicine of Sensory and Motor Organs, Division of Orthopedic Surgery, Faculty of Medicine, University of Miyazaki, Kiyotake, Miyazaki, Japan.
| | | | | | | | | | | | | | | |
Collapse
|
56
|
Talero E, Sánchez-Fidalgo S, de la Lastra CA, Illanes M, Calvo JR, Motilva V. Acute and chronic responses associated with adrenomedullin administration in experimental colitis. Peptides 2008; 29:2001-12. [PMID: 18708104 DOI: 10.1016/j.peptides.2008.07.013] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2008] [Revised: 07/07/2008] [Accepted: 07/10/2008] [Indexed: 01/03/2023]
Abstract
Adrenomedullin (AM) is a 52 amino acid peptide and member of the calcitonin gene-related peptide (CGRP) super family. Given that AM has emerged as a potential immuno-regulatory and anti-inflammatory agent in various experimental models, this study has deepened into its possible therapeutic effect in intestinal inflammation analyzing the responses in both acute and chronic (14 and 21 days) phases of TNBS-induced colitis in rats. In the acute model, AM treatment reduced the incidence of diarrhea and the severity of colonic damage, and improved the survival rate at the three doses assayed (50, 100, and 200ng/kg animal). AM administration was able to reduce the early production of TNF-alpha and collaborated to maintaining basal levels of IFN-gamma and IL-10. In the chronic studies the peptide attenuated the extent of the damage with lesser incidence of weight loss and diarrhea (50 and 100ng/kg animal). Cellular neutrophil infiltration, with the subsequent increase in myeloperoxidase (MPO) levels caused by TNBS, was reduced after chronic AM administration. The peptide played a role in the evolution of Th1/Th2 cytokines balance and chronic disease recuperation: levels of proinflammatory TNF-alpha and IFN-gamma decreased and anti-inflammatory IL-10 increased significantly. Cyclooxygenase-2 (COX-2) and nitric oxide synthase (iNOS) protein expression were not modified by AM administration, although a reduction of nitric oxide (NO) production could be detected in the chronic model. These results support a role of AM as an anti-inflammatory factor with beneficial effects in intestinal inflammatory colitis.
Collapse
Affiliation(s)
- E Talero
- Department of Pharmacology, School of Pharmacy, University of Seville, C. Prof. Garcia Gonzalez n2, 41012 Seville, Spain
| | | | | | | | | | | |
Collapse
|
57
|
Hosokawa I, Hosokawa Y, Ozaki K, Nakae H, Matsuo T. Adrenomedullin suppresses tumour necrosis factor alpha-induced CXC chemokine ligand 10 production by human gingival fibroblasts. Clin Exp Immunol 2008; 152:568-75. [PMID: 18435806 DOI: 10.1111/j.1365-2249.2008.03647.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Periodontal disease is an inflammatory disorder characterized by the involvement of chemokines that are important for the recruitment of leucocytes. Several cytokines, including tumour necrosis factor alpha (TNF-alpha), are involved in regulating levels of chemokines in periodontal disease. CXC chemokine ligand 10 (CXCL10) is a chemokine related to the migration of T helper 1 cells. In this study, we examined CXCL10 expression in human gingival fibroblasts (HGFs). Moreover, we investigated the effects of adrenomedullin (AM), which is a multi-functional regulatory peptide, on the production of CXCL10 by HGFs. We revealed that TNF-alpha stimulation induced CXCL10 production by HGFs. HGFs expressed AM and AM receptors, calcitonin-receptor-like receptor (CRLR) and receptor-activity-modifying protein (RAMP) 2, mRNAs constitutively. AM treatment supressed CXCL10 production by TNF-alpha-stimulated HGFs. Moreover, we elucidated that AM produced by HGFs inhibited CXCL10 production by HGFs, because AM antagonist enhanced CXCL10 production by HGFs. TNF-alpha treatment enhanced CRLR and RAMP2 mRNA expression in HGFs. Furthermore, AM is expressed in human periodontal tissues, including both inflamed and clinically healthy tissues. These results suggest that the CXCL10 produced by HGFs may be involved in the migration of leucocytes into inflamed tissues and related to exacerbation of periodontal disease. AM might be a therapeutic target of periodontal disease, because AM can inhibit CXCL10 production by HGFs.
Collapse
Affiliation(s)
- I Hosokawa
- Department of Conservative Dentistry, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan.
| | | | | | | | | |
Collapse
|
58
|
Chan YF, O WS, Tang F. Adrenomedullin in the Rat Testis. I: Its Production, Actions on Testosterone Secretion, Regulation by Human Chorionic Gonadotropin, and Its Interaction with Endothelin 1 in the Leydig Cell1. Biol Reprod 2008; 78:773-9. [DOI: 10.1095/biolreprod.107.060871] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
|
59
|
Antimicrobial activity does not predict cytokine response to adrenomedullin or its shortened derivatives. Mediators Inflamm 2008; 2007:30987. [PMID: 18274636 PMCID: PMC2233874 DOI: 10.1155/2007/30987] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2007] [Revised: 07/09/2007] [Accepted: 09/05/2007] [Indexed: 11/18/2022] Open
Abstract
The aim of this study was to investigate cytokine release from oral keratinocytes and
fibroblasts in response to AM and shortened derivatives previously characterised in terms
of their antimicrobial activities. Cells were incubated with AM or its fragments
(residues 1-12, 1-21, 13-52, 16-21, 16-52, 22-52, 26-52, and 34-52), and culture supernatants
collected after 1, 2, 4, 8, and 24 hours. A time-dependant increase in production of interleukin1-α
and interleukin 1-β from keratinocytes in response to all peptides was demonstrated. However,
exposure to fragments compared to whole AM resulted in reduced production of these
cytokines (60% mean reduction at 24 hours,
P<.001). No consistent differences were shown
between the cytokine response elicited by antimicrobial and nonantimicrobial fragments.
The production of interleukin-6 and interleukin-8 did not change significantly with time or
peptide used. Fibroblast cells were relatively unresponsive to all treatments. This study
demonstrates that antimicrobial activity does not predict cytokine response to adrenomedullin
or its shortened derivatives.
Collapse
|
60
|
Dani C, Pavoni V, Corsini I, Longini M, Gori G, Giannesello L, Perna A, Gritti G, Paternostro F, Forestieri A, Buonocore G, Rubaltelli FF. Inhaled nitric oxide combined with prostacyclin and adrenomedullin in acute respiratory failure with pulmonary hypertension in piglets. Pediatr Pulmonol 2007; 42:1048-56. [PMID: 17902148 DOI: 10.1002/ppul.20695] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Our aim was to evaluate if the combined inhalation of both nitric oxide (iNO) and aerosolized prostacyclin or iNO and adrenomedullin (ADM) is more effective in lowering pulmonary arterial pressure (PAP) and improving oxygenation than nitric oxide alone in an animal model with pulmonary hypertension (PH). Moreover, we studied the effect on pulmonary mechanics, surfactant activity, and pulmonary oxidative stress of the different treatments. Twenty-eight piglets with acute lung injury induced by lung lavages with saline were randomized to receive nitric oxide, nitric oxide plus prostacyclin, nitric oxide plus ADM or saline, after. Dynamic compliance, tidal volume, and airway resistance were measured. Lung tissue oxidation was evaluated by measuring total hydroperoxide and advanced oxidation protein products in bronchial aspirate samples. Surface surfactant activity was studied using Capillary Surfactometer. Inhaled nitric oxide combined with prostacyclin or ADM was more effective than nitric oxide alone in lowering PAP and improving oxygenation. Nitric oxide alone or combined increased lung compliance and tidal volume, and decreased airway resistance. No effects on surfactant surface activity and lung tissue oxidation were observed. The treatment with nitric oxide alone or combined with prostacyclin or ADM were effective in decreasing mean PAP and improving oxygenation in a piglet model of PH. However, nitric oxide plus prostacyclin and nitric oxide plus ADM were more effective than nitric oxide alone. The combination of aerosolized prostacyclin and ADM with nitric oxide might have a role in the treatment of infants with PH refractory to nitric oxide alone.
Collapse
Affiliation(s)
- Carlo Dani
- Department of Surgical and Medical Critical Care, Section of Neonatology, Careggi University Hospital of Florence, Florence, Italy.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
61
|
Man SY, Hwang ISS, Li YY, O WS, Sheng HP, Tang F. Differential regulation of adrenomedullin gene expression in the fundic and pyloric regions of the rat stomach during acute and chronic starvation. Neuropeptides 2007; 41:177-87. [PMID: 17335899 DOI: 10.1016/j.npep.2006.12.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2006] [Revised: 12/14/2006] [Accepted: 12/14/2006] [Indexed: 11/24/2022]
Abstract
Adrenomedullin (AM) has been shown to be present in the stomach but the role of gastric AM is obscure. To investigate the effects of starvation on AM in the stomach, we studied the changes in gene expression of preproadrenomedullin (preproAM) and AM receptors by reverse transcription-polymerase chain reaction (RT-PCR), and tissue AM concentrations by radioimmunoassay (RIA) in the fundus and pylorus of the stomach of rats subjected to either acute (1-day) or chronic (4-day) starvation. An up-regulation of preproAM gene expression was observed in the fundus after acute starvation, and in the pylorus after chronic starvation. Immunoreactive AM (ir-AM) levels were increased in both fundus and pylorus after chronic starvation. In addition, marked reductions in the gene expression of fundic calcitonin receptor-like receptor (CRLR) and receptor activity-modifying protein (RAMP) 3 as well as the pyloric CRLR and RAMP2 were observed in the chronically starved rats. The present study suggests that the gene expression of preproadrenomedullin mRNA is differentially regulated by starvation in the different parts of the stomach.
Collapse
Affiliation(s)
- Siu-Yin Man
- Department of Physiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China
| | | | | | | | | | | |
Collapse
|
62
|
Li Y, Jiang C, Wang X, Zhang Y, Shibahara S, Takahashi K. Adrenomedullin is a novel adipokine: adrenomedullin in adipocytes and adipose tissues. Peptides 2007; 28:1129-43. [PMID: 17433499 DOI: 10.1016/j.peptides.2007.03.005] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2007] [Revised: 03/01/2007] [Accepted: 03/01/2007] [Indexed: 01/23/2023]
Abstract
Adrenomedullin (AM) is a multifunctional regulatory peptide that is produced and secreted by various types of cells. The production and the secretion of AM have been demonstrated in cultured adipocytes and adipose tissues. Inflammatory cytokines such as tumor necrosis factor-alpha (TNF-alpha) and lipopolysaccharide are strong stimulators for AM expression in adipocytes. Furthermore, AM expression in the adipose tissue is increased in obesity, and plasma concentrations of AM are increased in obese subjects. One possible (patho)physiological role of AM secreted by adipose tissue may be actions against complications of the metabolic syndrome characterized by obesity, type 2 diabetic mellitus and hypertension, via its antioxidant and potent vasodilator effects. These findings indicate that AM is a new member of the adipokine family.
Collapse
Affiliation(s)
- Yin Li
- Department of Physiology and Pathophysiology, Peking University Health Science Center, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing 100083, PR China
| | | | | | | | | | | |
Collapse
|
63
|
Hwang ISS, Fung ML, Liong EC, Tipoe GL, Tang F. Age-related changes in adrenomedullin expression and hypoxia-inducible factor-1 activity in the rat lung and their responses to hypoxia. J Gerontol A Biol Sci Med Sci 2007; 62:41-9. [PMID: 17301036 DOI: 10.1093/gerona/62.1.41] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Male rats aged 3 months, 12 months and 20 months were subjected to breathing 8% oxygen for 6 hours. Lung preproadrenomedullin (AM) messenger RNA (mRNA) levels were measured by solution hybridization-RNase protection assay while AM was measured by radioimmunoassay. The binding of hypoxia-inducible factor-1alpha (HIF-1alpha) to DNA was determined by electrophoretic mobility shift. There was an age-related increase in basal levels of preproAM mRNA and AM and of the binding of hypoxia-inducible factor (HIF) to DNA. Upon hypoxic stimulation, HIF binding to DNA increased in the young and middle-aged rats, but not in the old rats. AM gene expression increased in response to hypoxia in rats of all ages, but the increase was much less in the old rats. AM peptide levels in the lung decreased with age in hypoxia. In a separate experiment, male rats aged 3 months and 20 months were subjected to hypoxia as described above. PreproAM, calcitonin receptor-like receptor (CRLR), receptor activity modifying protein (RAMP) mRNA, HIF-1 and peptidyl-glycine-amidating monooxygenase (PAM) mRNA levels were measured by reverse transcription-polymerase chain reaction. All except PAM showed a decrease in basal levels and a diminished response to hypoxia in the old rats. Polysome profiling demonstrated decreases in the percentages of translatable preproAM mRNA in response to hypoxia, with a greater decrease in the old than the young rats. It is concluded that an age-dependent decrease in the hypoxic response of the AM system in the lung was associated with high basal levels of HIF activity and AM expression in the old rats, and a lower proportion of translatable preproAM mRNA in the old rats in response to hypoxia. Thus, the HIF-AM pathway may be impaired in the aged lung, and other mechanisms may be present to maintain an AM response to hypoxia.
Collapse
Affiliation(s)
- Isabel S S Hwang
- Department of Physiology, Faculty of Medicine, University of Hong Kong, Pokfulam, China
| | | | | | | | | |
Collapse
|
64
|
Go AGG, Chow KHM, Hwang ISS, Tang F. Adrenomedullin and its receptor components in adipose tissues: Differences between white and brown fats and the effects of adrenergic stimulation. Peptides 2007; 28:920-7. [PMID: 17250927 DOI: 10.1016/j.peptides.2006.12.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2006] [Revised: 12/06/2006] [Accepted: 12/07/2006] [Indexed: 11/22/2022]
Abstract
Male Sprague-Dawley rats were subcutaneously injected with 2.5mg/kg phenylephrine or 2.5mg/kg isoproterenol or both (2.5mg/kg for each drug) for 4 days, twice a day. Samples of scapular brown adipose tissue (BAT) and epididymal white adipose tissue (WAT) were collected for the measurement of adrenomedullin (AM) levels and the gene expression of preproAM, calcitonin receptor like receptor (CRLR) and its activity modifying proteins (RAMPs) by radioimmunoassay and RT-PCR. These values were compared with those in the rats that received 0.9% saline. The gene expression of AM and AM receptor components in BAT are much less than that in epididymal WAT. In BAT there were an increase in AM peptide level after a combined treatment of alpha(1) and beta adrenoceptor agonists and increases in preproAM mRNA levels for rats treated with alpha(1) and beta receptor agonists alone or in combination. Both CRLR and RAMP2 mRNA levels of alphabeta group were increased significantly. In WAT, AM peptide level, RAMP1 and RAMP2 mRNA expression levels were augmented in the alpha group while CRLR mRNA level was enhanced in the beta group. The levels of AM, its receptor and RAMPs are much less in BAT than in WAT but adrenergic stimulation has a greater effect on the AM and its receptor components in BAT than those in WAT. AM stimulates lipolysis and increases the level of uncoupling protein-1 (UCP-1) in BAT. It may therefore enhance thermogenesis by increasing the availability of free fatty acids substrate as well as the UCP-1 level on the mitochondrial membrane.
Collapse
MESH Headings
- Adipose Tissue, Brown/chemistry
- Adipose Tissue, Brown/drug effects
- Adipose Tissue, Brown/metabolism
- Adipose Tissue, White/chemistry
- Adipose Tissue, White/drug effects
- Adipose Tissue, White/metabolism
- Adrenergic Agents/administration & dosage
- Adrenergic Agents/pharmacology
- Adrenomedullin/genetics
- Adrenomedullin/metabolism
- Animals
- Blotting, Western
- Body Weight/drug effects
- Calcitonin Receptor-Like Protein
- Gene Expression Regulation/drug effects
- Injections, Subcutaneous
- Intracellular Signaling Peptides and Proteins/genetics
- Intracellular Signaling Peptides and Proteins/metabolism
- Ion Channels/metabolism
- Isoproterenol/administration & dosage
- Isoproterenol/pharmacology
- Lipolysis/drug effects
- Male
- Membrane Proteins/genetics
- Membrane Proteins/metabolism
- Mitochondrial Proteins/metabolism
- Phenylephrine/administration & dosage
- Phenylephrine/pharmacology
- Protein Precursors/genetics
- Protein Precursors/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Radioimmunoassay
- Rats
- Rats, Sprague-Dawley
- Receptor Activity-Modifying Proteins
- Receptors, Adrenomedullin
- Receptors, Calcitonin/genetics
- Receptors, Calcitonin/metabolism
- Receptors, Peptide/genetics
- Receptors, Peptide/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Uncoupling Protein 1
Collapse
Affiliation(s)
- Adi G G Go
- Department of Physiology, Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Pokfulam, Hong Kong, China
| | | | | | | |
Collapse
|
65
|
Marinoni E, Vellucci O, Letizia C, Sessa M, Moscarini M, Di Iorio R. The level of adrenomedullin immunoreactivity in seminal fluid is higher in oligozoospermic subjects and correlates with semen biochemical parameters. Eur J Obstet Gynecol Reprod Biol 2007; 131:169-75. [PMID: 16854513 DOI: 10.1016/j.ejogrb.2006.06.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2005] [Revised: 05/24/2006] [Accepted: 06/13/2006] [Indexed: 11/15/2022]
Abstract
OBJECTIVE The newly discovered vasoactive peptide, adrenomedullin, and its receptors are widely distributed in various non-vascular tissues. Recent studies have suggested the possible regulatory role of adrenomedullin (AM) at several levels of the pituitary-gonadal axis. We determined the level of adrenomedullin-like immunoreactivity in the seminal fluid and examined its possible correlation with routine semen parameters, semen biochemical levels or plasma levels of FSH, LH, testosterone or prolactin. MATERIALS AND METHODS A total of 51 males were divided into three groups according to semen analysis: (i) normospermic (n=19); (ii) oligozoospermic (n=17); (iii) azoospermic (n=15). All the subjects were submitted to hormone analysis (LH, FSH, testosterone, prolactin), routine semen parameters and semen biochemical levels (fructosio, citric acid, L-carnitine, nitric oxide) evaluation. AM was determined in plasma and seminal fluid using a specific radioimmunoassay. RESULTS Mean AM concentration in seminal plasma was higher in oligozoospermic subjects than in normospermic males. In patients with non-obstructive azoospermia AM in semen was significantly lower than in patients with obstructive azoospermia. Semen AM levels correlated negatively with citric acid concentrations in oligozoospermic subjects. In patients with obstructive azoospermia AM in seminal fluid was correlated with citric acid levels. There was a relationship between plasma AM and prolactin. CONCLUSIONS We conclude that in human seminal fluid AM concentration is increased in infertile oligozoospermic patients and derives very likely from the prostate. Its role in the regulation of male fertility, however has to be understood.
Collapse
Affiliation(s)
- Emanuela Marinoni
- Department of Gynecology, Perinatology and Child Health, Viale Regina Elena 324, I-00161 Rome, Italy.
| | | | | | | | | | | |
Collapse
|
66
|
Gonzalez-Rey E, Chorny A, O'Valle F, Delgado M. Adrenomedullin protects from experimental arthritis by down-regulating inflammation and Th1 response and inducing regulatory T cells. THE AMERICAN JOURNAL OF PATHOLOGY 2007; 170:263-71. [PMID: 17200199 PMCID: PMC1762686 DOI: 10.2353/ajpath.2007.060596] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Rheumatoid arthritis is a chronic autoimmune disease of unknown etiology characterized by chronic inflammation in the joints and subsequent destruction of the cartilage and bone. The present study proposes a new strategy for the treatment of arthritis: the administration of the immunomodulatory neuropeptide adrenomedullin. Treatment with adrenomedullin significantly reduced incidence and severity of collagen-induced arthritis, an experimental model of rheumatoid arthritis, completely abrogating joint swelling and destruction of cartilage and bone. The therapeutic effect of adrenomedullin was associated with a striking reduction of the two deleterious components of the disease, ie, the Th1-driven autoimmune and inflammatory responses. Adrenomedullin also induced the generation and/or activation of efficient CD4+ CD25+ regulatory T cells in arthritis with capacity to suppress autoreactive response and restore immune tolerance, which could play a pivotal role in the therapeutic effect of adrenomedullin on experimental arthritis contributing to the restoration of immune tolerance.
Collapse
Affiliation(s)
- Elena Gonzalez-Rey
- Institute of Parasitology and Biomedicine, Spanish Council of Scientific Research, Granada, Spain.
| | | | | | | |
Collapse
|
67
|
Gonzalez-Rey E, Chorny A, Delgado M. Regulation of immune tolerance by anti-inflammatory neuropeptides. Nat Rev Immunol 2007; 7:52-63. [PMID: 17186031 DOI: 10.1038/nri1984] [Citation(s) in RCA: 165] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The induction of antigen-specific tolerance is essential to maintain immune homeostasis, control autoreactive T cells, prevent the onset of autoimmune diseases and achieve tolerance of transplants. Inflammation is a necessary process for eliminating pathogens, but can lead to serious deleterious effects in the host if left unchecked. Identifying the endogenous factors that control immune tolerance and inflammation is a key goal in the field of immunology. In the last decade, various neuropeptides that are produced by immune cells with potent anti-inflammatory actions were found to participate in the maintenance of tolerance in different immunological disorders.
Collapse
Affiliation(s)
- Elena Gonzalez-Rey
- Instituto de Parasitología y Biomedicina, Consejo Superior de Investigaciones Cientificas, Avenida Conocimiento, Parque Tecnológico de Ciencias de la Salud, Granada 18100, Spain
| | | | | |
Collapse
|
68
|
Ertmer C, Van Aken H, Westphal M. Adrenomedullin in the Treatment of Cardiovascular Dysfunction and Sepsis. Intensive Care Med 2007. [DOI: 10.1007/978-0-387-49518-7_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
69
|
|
70
|
Li YY, Hwang ISS, O WS, Tang F. Adrenomedullin Peptide: Gene Expression of Adrenomedullin, its Receptors and Receptor Activity Modifying Proteins, and Receptor Binding in Rat Testis—Actions on Testosterone Secretion1. Biol Reprod 2006; 75:183-8. [PMID: 16672720 DOI: 10.1095/biolreprod.106.052274] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Adrenomedullin (ADM) has been shown to be present in the human and rat male reproductive systems. This study demonstrates the expression of ADM in the rat testis and its effect on the secretion of testosterone. Whole testicular extracts had 5.43 +/- 0.42 fmol of immunoreactive ADM per milligram of protein and 84 +/- 8 fg of ADM mRNA per picogram of Actb (beta-actin) mRNA. Immunocytochemical studies showed positive ADM immunostaining in the Leydig cells and in the Sertoli cells. Gel filtration chromatography of testicular extracts showed two peaks, with the predominant one eluting at the position of the ADM precursor. Furthermore, the testis was shown to coexpress mRNAs encoding the calcitonin receptor-like receptor and receptor activity modifying protein 1 (Ramp1), Ramp2, and Ramp3. These account for the specific binding of ADM to the testis, which was partially inhibited by human ADM (22-52) and by human calcitonin gene-related peptide (8-37), the ADM and calcitonin gene-related peptide receptor antagonists, respectively. Administration of ADM to testicular blocks in vitro resulted in a dose-dependent inhibition of hCG-stimulated release of testosterone, which was abolished by the administration of ADM (22-52). Our results suggest a paracrine effect of ADM on testicular steroidogenesis.
Collapse
Affiliation(s)
- Yuk-Yin Li
- Department of Physiology, The University of Hong Kong, Hong Kong
| | | | | | | |
Collapse
|
71
|
Hwang ISS, Tang F, Leung PP, Li YY, Fan ST, Luk JMC. The gene expression of adrenomedullin, calcitonin-receptor-like receptor and receptor activity modifying proteins (RAMPs) in CCl4-induced rat liver cirrhosis. ACTA ACUST UNITED AC 2006; 135:69-77. [PMID: 16713642 DOI: 10.1016/j.regpep.2006.04.006] [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: 01/13/2006] [Revised: 04/04/2006] [Accepted: 04/09/2006] [Indexed: 12/13/2022]
Abstract
This study was undertaken to determine AM expression in carbon tetrachloride (CCl4)-induced liver cirrhosis developed with peritoneal ascites. Sprague-Dawley rats received subcutaneous injections of CCl4 twice weekly in olive oil (1:1, 0.3 ml per kg body weight) for 6 or 12 weeks until ascites developed, or saline in olive oil as control. At 6 weeks, fibrosis developed and at 12 weeks cirrhosis developed with ascites formation. At both 6 and 12 weeks, increases in plasma renin and AM were evident, as was the gene expression of AM. At 12 weeks after CCl4 injection, the gene expression of calcitonin-like-receptor (CRLR) and receptor activity modifying proteins (RAMP1, RAMP2 and RAMP3) were all elevated when compared to the control. The results suggest that liver cirrhosis increases mRNA expressions of AM, CRLR and RAMP1, RAMP2 and RAMP3 and that the increase in AM gene expression precedes the development of cirrhosis. The increase in AM synthesis as reflected by an increase in AM gene expression, together with a lack of increase in AM peptide at both 6 and 12 weeks may suggest an elevation of AM release. Given the potent vasodilatory action of AM, the increase in the synthesis and release of AM in the cirrhotic liver may also contribute to peripheral vasodilatation in liver cirrhosis.
Collapse
Affiliation(s)
- Isabel Shui Shan Hwang
- Center for the Study of Liver Disease, The University of Hong Kong, Pokfulam, Hong Kong, China
| | | | | | | | | | | |
Collapse
|
72
|
Gonzalez-Rey E, Chorny A, Varela N, Robledo G, Delgado M. Urocortin and adrenomedullin prevent lethal endotoxemia by down-regulating the inflammatory response. THE AMERICAN JOURNAL OF PATHOLOGY 2006; 168:1921-30. [PMID: 16723707 PMCID: PMC1606636 DOI: 10.2353/ajpath.2006.051104] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 02/28/2006] [Indexed: 12/17/2022]
Abstract
Urocortin 1 (UCN) and adrenomedullin (AM) are two neuropeptides that have emerged as potential endogenous anti-inflammatory factors based on their production by and binding to immune cells. Because human septic shock involves excessive inflammatory cytokine production, we investigated the effect of UCN and AM in the production of inflammatory mediators and their therapeutic actions in two models of septic shock. Both peptides down-regulated the production of inflammatory mediators by endotoxin-activated macrophages. The administration of UCN or AM protected against lethality after cecal ligation and puncture or after injection of bacterial endotoxin and prevented septic shock-associated histopathology, such as infiltration of inflammatory cells and intravascularly disseminated coagulation in various target organs. The therapeutic effect of UCN and AM was mediated by decreasing the local and systemic levels of a wide spectrum of inflammatory mediators, including cytokines, chemokines, and the acute phase protein serum amyloid A. Importantly, UCN or AM treatment was therapeutically effective in established endotoxemia. In conclusion, UCN and AM could represent two multistep therapeutic agents for human septic shock to be used in combination with other immunomodulatory agents or complementary as anti-inflammatory factors to other therapies.
Collapse
Affiliation(s)
- Elena Gonzalez-Rey
- Instituto de Parasitologia y Biomedicina, Consejo Superior de Investigaciones Cientificas, Avd. Conocimiento, Parque Tecnologico Ciencias de la Salud, Granada 18100, Spain
| | | | | | | | | |
Collapse
|
73
|
Yanagawa B, Nagaya N. Adrenomedullin: molecular mechanisms and its role in cardiac disease. Amino Acids 2006; 32:157-64. [PMID: 16583314 DOI: 10.1007/s00726-005-0279-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2005] [Accepted: 12/03/2005] [Indexed: 10/24/2022]
Abstract
Adrenomedullin (AM) is a potent, long-lasting vasoactive peptide originally isolated from human pheochromocytoma. Since its discovery, serum and tissue AM expression have been shown to be increased in experimental models and in patients with cardiac hypertrophy, myocardial infarction and end-stage heart failure with several beneficial effects. Considerable evidence exists for a wide range of autocrine, paracrine and endocrine mechanisms for AM which include vasodilatory, anti-apoptotic, angiogenic, anti-fibrotic, natriuretic, diuretic and positive inotropic. Thus, through regulation of body fluid or direct cardiac mechanisms, AM has additive and beneficial effects in the context of heart disease. Notable molecular mechanisms of AM include cyclic adenosine monophosphate, guanosine-3',5'-monophosphate, PI3K/Akt and MAPK-ERK-mediated cascades. Given the endogenous and multifunctional nature of AM, we consider this molecule to have great potential in the treatment of cardiovascular diseases. In agreement, early experimental and preliminary clinical studies suggest that AM is a new and promising therapy for cardiovascular diseases.
Collapse
Affiliation(s)
- B Yanagawa
- Department of Regenerative Medicine and Tissue Engineering, National Cardiovascular Center Research Institute, Osaka, Japan
| | | |
Collapse
|
74
|
Li YY, Wong LYF, Cheung BMY, Hwang ISS, Tang F. Differential induction of adrenomedullin, interleukins and tumour necrosis factor-alpha by lipopolysaccharide in rat tissues in vivo. Clin Exp Pharmacol Physiol 2006; 32:1110-8. [PMID: 16445578 DOI: 10.1111/j.1440-1681.2005.04307.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The aim of the present study was to determine the temporal changes in tissue adrenomedullin (AM) and cytokine contents and cytokine and preproAM mRNA levels in the kidney, liver, adrenal gland and spleen of lipopolysaccharide (LPS)-treated rats. Rats were injected with LPS (10 mg/kg, i.p.). Radioimmunoassay and solution hybridization-RNase protection assays were used to follow the changes in AM and its mRNA levels, respectively; ELISA and reverse transcription-polymerase chain reaction were used to follow the changes in cytokines and their mRNA levels, respectively. In the kidney, the preproAM mRNA levels were increased 1 and 3 h after LPS treatment, whereas AM levels were decreased at 3 h. Interleukin (IL)-6 and IL-1beta levels were increased at 3 and 6 h, respectively. The preproAM mRNA levels were elevated in the liver 3 h after LPS injection. Concentrations of tumour necrosis factor (TNF)-alpha and IL-1beta were increased at l and 6 h, respectively. There were no changes in the levels of either preproAM mRNA or AM in the adrenal gland and the spleen. In the spleen, TNF-alpha levels were elevated at 1 and 3 h after LPS injection and IL-1beta was elevated at 1 and 6 h after LPS injection, whereas in the adrenal gland IL-1beta was elevated at 6 h after injection. The mRNA levels of the three cytokines were elevated at all three time intervals examined in the kidney, liver, adrenal gland and spleen, with the exception that TNF-alpha mRNA was not elevated in the adrenal gland at 6 h after LPS injection and IL-1beta mRNA was not elevated in the spleen at 3 and 6 h. The plasma concentrations of TNF-alpha were increased at 1 and 3 h after LPS injection, whereas plasma concentration of IL-1beta and IL-6 were elevated at 3 and 6 h for both. The present results suggest that the biosynthesis and secretion of AM may be differentially regulated in various tissues of rats injected with LPS and that AM may interact with cytokines during inflammation.
Collapse
Affiliation(s)
- Yuk-Yin Li
- Department of Physiology, The University of Hong Kong, Hong Kong, China
| | | | | | | | | |
Collapse
|
75
|
Hayakawa K, Meng Y, Hiramatsu N, Kasai A, Yamauchi K, Yao J, Kitamura M. Priming of glomerular mesangial cells by activated macrophages causes blunted responses to proinflammatory stimuli. THE JOURNAL OF IMMUNOLOGY 2006; 176:2529-37. [PMID: 16456014 DOI: 10.4049/jimmunol.176.4.2529] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Macrophage-mesangial cell interaction plays a crucial role in the pathogenesis of glomerulonephritis. Activated macrophages trigger mesangial cells to express an array of inflammation-associated genes via activation of NF-kappaB and AP-1. However, this inflammatory response is often transient and subsides spontaneously. We found that mesangial cells activated by bystander macrophages showed blunted responses of NF-kappaB to subsequent macrophage exposure. It was associated with sustained levels of IkappaBbeta, but not IkappaBalpha. The tolerance observed was reversible and reproduced by conditioned media from activated macrophages (macrophage-conditioned medium (MphiCM)). In vivo priming of mesangial cells by activated glomerular macrophages also caused the tolerance of mesangial cells. The macrophage-derived tolerance inducers were heat-labile, and multiple molecules were involved. Among inflammatory cytokines produced by macrophages, TNF-alpha and IL-1beta were able to induce mesangial cell tolerance dose-dependently. The mesangial cell tolerance was also observed in activation of the MAPK-AP-1 pathway; i.e., phosphorylation of ERK, JNK, and p38 MAPK by macrophages was blunted when the cells were pre-exposed to MphiCM. Induction of c-fos and c-jun was also abrogated in mesangial cells pre-exposed to MphiCM, and the suppression was attenuated by blockade of MAPK activation during the first exposure to MphiCM. These data elucidated that mesangial cells, once exposed to macrophages, become insensitive to subsequent activation by macrophages and proinflammatory stimuli. This self defense of glomerular cells may play a role in the resolution of macrophage-mediated, acute glomerulonephritis.
Collapse
|
76
|
Zudaire E, Martínez A, Garayoa M, Pío R, Kaur G, Woolhiser MR, Metcalfe DD, Hook WA, Siraganian RP, Guise TA, Chirgwin JM, Cuttitta F. Adrenomedullin is a cross-talk molecule that regulates tumor and mast cell function during human carcinogenesis. THE AMERICAN JOURNAL OF PATHOLOGY 2006; 168:280-91. [PMID: 16400030 PMCID: PMC1592665 DOI: 10.2353/ajpath.2006.050291] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/29/2005] [Indexed: 11/20/2022]
Abstract
We have previously demonstrated that adrenomedullin (AM) plays a critical role as an autocrine/paracrine tumor cell survival factor. We now present evidence that AM is an important regulator of mast cell (MC) function and that this modulation is potentially involved in tumor promotion. AM induced histamine or beta-hexosaminidase release from rat and human MCs through a receptor-independent pathway. AM was chemotactic for human MCs and stimulated mRNA expression of vascular endothelial growth factor, monocyte chemoattractant protein-1, and basic fibroblast growth factor in this cell type. Differentiated but not undifferentiated human MCs responded to hypoxic insult with elevated AM mRNA/protein expression. Using confocal microscopy, we identified AM-producing MCs in tumor infiltrates of human breast and lung cancer patients. In mixed culture assays the AM-producing human MC line HMC-1 augmented both anchorage-dependent and -independent growth of human lung cancer A549 cells, an effect that was suppressed by MC-targeted siRNA AM knockdown. Finally, HMC-1 cells induced in vivo angiogenesis as assessed by directed in vivo angiogenesis assay analysis; neutralizing anti-AM monoclonal antibody blocked this ability. Our collective data suggest a new role for AM as a cross-talk molecule that integrates tumor and MC communication, underlying a unique promotion mechanism of human cancers.
Collapse
Affiliation(s)
- Enrique Zudaire
- CCBB, CCR, National Cancer Institute, Bldg. 10, Rm., 12N226, Bethesda, MD 20892, USA.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
77
|
Haas CS, Martinez RJ, Attia N, Haines GK, Campbell PL, Koch AE. Chemokine receptor expression in rat adjuvant-induced arthritis. ACTA ACUST UNITED AC 2005; 52:3718-30. [PMID: 16320322 DOI: 10.1002/art.21476] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Chemokine receptors mediate leukocyte migration into inflamed rheumatoid arthritis (RA) synovial tissue (ST). Knowledge of their distribution is crucial for understanding the evolution of the inflammatory process. In this study, we used rat adjuvant-induced arthritis (AIA), a model for RA, to define the temporospatial expression of chemokine receptors. METHODS ST from rats with AIA was immunostained, the percentage of cells expressing each receptor was determined, and findings were correlated with levels of inflammation. Chemokine receptor expression was evaluated on rat macrophages in vitro. RESULTS CCR1, a receptor for macrophage inflammatory protein 1alpha (MIP-1alpha)/CCL3 and RANTES/CCL5, exhibited high constitutive expression on macrophages in AIA. CCR5, binding MIP-1alpha/CCL3 and RANTES/CCL5, was up-regulated on ST macrophages during the course of AIA, correlating with macrophage expression of CCR2, a receptor for monocyte chemoattractant protein 1/CCL2. Endothelial cell (EC) CCR2 was down-regulated as arthritis progressed, inversely correlating with inflammation. CCR3, another RANTES/CCL5 receptor, was constitutively high on macrophages in vivo and in vitro, with down-regulation during AIA. CXCR4, a receptor for stromal cell-derived factor 1/CXCL12), was prominently up-regulated on ECs, preceding the peak of inflammation. CONCLUSION These findings show that 1) constitutive expression of CCR1 on macrophages remains high during AIA; 2) CCR2 and CCR3 may play a role in initial recruitment of leukocytes to ST in AIA; 3) macrophage expression of CCR2 and CCR5 may be important for sustaining inflammatory changes; and 4) EC CXCR4 may be a harbinger of inflammatory changes. Our results may help guide chemokine receptor blockade-targeting treatment strategies in inflammatory arthritis.
Collapse
MESH Headings
- Animals
- Arthritis, Experimental/immunology
- Arthritis, Experimental/metabolism
- Cell Line
- Female
- Macrophages, Alveolar/cytology
- Macrophages, Alveolar/immunology
- Macrophages, Alveolar/metabolism
- Myocytes, Smooth Muscle/immunology
- Myocytes, Smooth Muscle/metabolism
- Rats
- Rats, Inbred Lew
- Receptors, CCR1
- Receptors, CCR2
- Receptors, CCR3
- Receptors, CCR5/metabolism
- Receptors, CXCR4/metabolism
- Receptors, Chemokine/metabolism
- Synovial Membrane/immunology
- Synovial Membrane/metabolism
- Up-Regulation
Collapse
Affiliation(s)
- Christian S Haas
- University of Michigan Medical School, Ann Arbor, MI 48109-0680, USA
| | | | | | | | | | | |
Collapse
|