adrenomedullin and Inflammation

Microglial cells are responsible for immune surveillance within the CNS. They respond to noxious stimuli by releasing inflammatory mediators and mounting an effective inflammatory response. This is followed by release of anti-inflammatory mediators and resolution of the inflammatory response. Alterations to this delicate process may lead to tissue damage, neuroinflammation, and neurodegeneration. Chronic pain, such as inflammatory or neuropathic pain, is accompanied by neuroimmune activation, and the role of glial cells in the initiation and maintenance of chronic pain has been the subject of increasing research over the last two decades. Neuropeptides are small amino acidic molecules with the ability to regulate neuronal activity and thereby affect various functions such as thermoregulation, reproductive behavior, food and water intake, and circadian rhythms. Neuropeptides can also affect inflammatory responses and pain sensitivity by modulating the activity of glial cells. The last decade has witnessed growing interest in the study of microglial activation and its modulation by neuropeptides in the hope of developing new therapeutics for treating neurodegenerative diseases and chronic pain. This review summarizes the current literature on the way in which several neuropeptides modulate microglial activity and response to tissue damage and how this modulation may affect pain sensitivity.

Topics: Adrenomedullin; Animals; Calcitonin Gene-Related Peptide; Ghrelin; Humans; Inflammation; Inflammation Mediators; Leptin; Macrophage Activation; Microglia; Neuralgia; Neurodegenerative Diseases; Neuroglia; Neuropeptide Y; Neuropeptides; Pain; Pro-Opiomelanocortin; Tachykinins; Vasoactive Intestinal Peptide

Diabetic retinopathy (DR) is the main cause of working-age adult-onset blindness. The currently available treatments for DR are applicable only at advanced stages of the disease and are associated with significant adverse effects. In early stages of DR the only therapeutic strategy that physicians can offer is a tight control of the risk factors for DR. Therefore, new pharmacological treatments for these early stages of the disease are required. In order to develop therapeutic strategies for early stages of DR new diagnostic tools are urgently needed. In this regard, circulating biomarkers could be useful to detect early disease, to identify those diabetic patients most prone to progressive worsening who ought to be followed up more often and who could obtain the most benefit from these therapies, and to monitor the effectiveness of new drugs for DR before more advanced DR stages have been reached. Research of biomarkers for DR has been mainly based on the pathogenic mechanism involved in the development of DR (i.e., AGEs, oxidative stress, endothelial dysfunction, inflammation, and proangiogenic factors). This review focuses on circulating biomarkers at both early and advanced stages that could be relevant for the prediction or detection of DR.

Topics: Adrenomedullin; Arginine; Autoantibodies; Basement Membrane; Biomarkers; C-Reactive Protein; Collagen Type IV; Diabetic Retinopathy; E-Selectin; Endothelial Progenitor Cells; Extracellular Matrix; Glycation End Products, Advanced; Homocysteine; Humans; Inflammation; Intercellular Adhesion Molecule-1; Interleukin-6; Laminin; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; MicroRNAs; Retinol-Binding Proteins, Plasma; RNA, Messenger; Tissue Inhibitor of Metalloproteinase-1; Tumor Necrosis Factor-alpha; Vascular Cell Adhesion Molecule-1

The increase of pronociceptive mediators in the dorsal root ganglia (DRG) and spinal dorsal horn is an important mechanism in the pathogenesis of inflammatory pain and opioid tolerance. Adrenomedullin (AM) belongs to calcitonin gene-related peptide (CGRP) family and has been recently demonstrated to be a pain-related peptide. It has also been shown that the expression and release of AM are increased in the DRG and spinal dorsal horn during inflammation and repeated use of morphine. Intrathecal administration of the selective AM receptor antagonist AM22-52 abolishes inflammatory pain and morphine tolerance, suggesting that enhanced AM receptor signaling in the DRG and spinal dorsal horn contributes to the induction of inflammatory pain and morphine tolerance. The present review highlights the recent developments regarding the involvement of AM in these two disorders. The neurological mechanisms of AM's actions are also discussed.

Topics: Adrenomedullin; Animals; Calcitonin Gene-Related Peptide; Drug Tolerance; Ganglia, Spinal; Inflammation; Morphine; Pain; Peptide Fragments; Rats; Rats, Sprague-Dawley; Receptors, Adrenomedullin

Intermedin/adrenomedullin-2 (IMD/AM2) belongs to the calcitonin gene-related peptide (CGRP) / adrenomedullin (AM) family. The biological actions of this family are attributed to their actions at three receptor subtypes comprising the calcitonin receptor-like receptor (CLR) complexed with one of three receptor activity modifying proteins. In contrast to AM and CGRP, IMD binds non-selectively to all three receptor subtypes: CGRP, AM1, AM2. The peptide displays an overlapping but differential and more restricted distribution across the healthy systemic and pulmonary vasculature, heart and kidney relative to CGRP and AM. This, combined with tissue, regional and cell-type specific receptor expression, underpins differences in regard to magnitude, potency and duration of haemodynamic, cardiac and renal effects of IMD relative to those of AM and CGRP, and receptor-subtype involvement. In common with other family members, IMD protects the mammalian vasculature, myocardium and kidney from acute ischaemia-reperfusion injury, chronic oxidative stress and pressure-loading; IMD inhibits apoptosis, attenuates maladaptive tissue remodelling and preserves cardiac and renal function. Robust upregulation of IMD expression in rodent models of cardiovascular and renal disease argues strongly for the pathophysiological relevance of this particular counter-regulatory peptide. Such findings are likely to translate well to the clinic: early reports indicate that IMD is expressed in and protects cultured human vascular and cardiac non-vascular cells from simulated ischaemia-reperfusion injury, primarily via the AM1 receptor, and may have utility as a plasma biomarker in cardiovascular disease. These observations should provide the rationale for short-term administration of the peptide in acute disease, including myocardial infarction, cerebrovascular insult, cardiac and renal failure.

Topics: Adrenomedullin; Animals; Calcitonin Gene-Related Peptide; Cardiovascular Diseases; Cardiovascular System; Humans; Inflammation; Kidney Diseases; Lung Diseases; Organ Specificity; Oxidative Stress; Peptide Hormones; Protective Agents; Receptors, Adrenomedullin; Receptors, Calcitonin Gene-Related Peptide; Reperfusion Injury

Community-acquired pneumonia (CAP) is the leading cause of death from infectious diseases worldwide, with an incidence of 0.3 to 0.5% in the adult population. A new diagnostic and prognostic approach relies on evaluation of biomarkers as an expression of the host's inflammatory response against the microorganism. C-reactive protein (CRP), procalcitonin (PCT), and cytokines are the most frequently studied, whereas pro-adrenomedullin (pro-ADM), pro-vasopressin (pro-VNP), and others are currently obtaining promising results. Their usefulness for diagnosis is limited, although PCT has been successfully used to guide prescription of antibiotics in patients with suspected CAP. Nevertheless, the accuracy of PCT in distinguishing between bacterial or viral infection and safely withholding antibiotics in CAP is the subject of debate. Analysis of systemic biomarkers in addition to clinical scores [Pneumonia Severity Index (PSI) or CURB-65 (confusion, urea, respiratory, blood pressure, >65 years)/CRB-65 (confusion, respiratory, blood pressure)] has been shown to improve 30 day mortality prediction and absence of severe complications. Pro-ADM is probably the biomarker that correlates most strongly with mortality prediction. During treatment, ~15% of hospitalized CAP patients develop treatment failure, and almost 6% may manifest rapidly progressive pneumonia. Initially increased and persistent raised levels of biomarkers and cytokines have been shown to identify patients at risk of treatment failure, thereby aiding clinical management. Data from the literature appear to support the use of biomarkers in routine clinical practice to improve the decision making in CAP.

Topics: Adrenomedullin; Anti-Bacterial Agents; Biomarkers; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Community-Acquired Infections; Cytokines; Humans; Inflammation; Pneumonia; Prognosis; Protein Precursors; Vasopressins

Biomarkers have been intensively studied in community-acquired pneumonia (CAP) in recent years. In the context of the CAPNETZ study we had the unique opportunity to evaluate old and new biomarkers in a multicentre study with a high number of patients.. In several substudies we found the following results: procalcitonin, CRP and leukocytes show highest values in patients with typical bacterial etiology of CAP, but do not allow individual prediction of etiology. Patients without antibiotic pre-treatment show higher values of biomarkers compared to patients with antibiotic pre-treatment. New cardiovascular biomarkers are good predictors for short- and long-term mortality in CAP, superior to the inflammatory markers procalcitonin, CRP and leukocytes and at least comparable to the clinical CRB-65 score. Pro-Adrenomedullin is among the new biomarkers the one with the best prognostic value.. Biomarkers correlate with the severity of CAP but do not allow individual prediction of etiology. New cardiovascular biomarkers are suitable for the evaluation of short- and long-term prognosis in CAP. The combination of several biomarkers reflecting different pathophysiological pathways has the potential to improve management of CAP in the future.

Topics: Adolescent; Adrenomedullin; Adult; Age Distribution; Aged; Aged, 80 and over; Atrial Natriuretic Factor; Biomarkers; Blood Pressure; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Cardiovascular Diseases; Community-Acquired Infections; Comorbidity; Endothelin-1; Female; Germany; Humans; Inflammation; Leukocyte Count; Male; Middle Aged; Pneumonia; Predictive Value of Tests; Protein Precursors; Respiratory Rate; Survival Analysis; Vasopressins; Young Adult

Although loss of endothelial barrier function is a hallmark of every acute inflammation and contributes to fatal loss of organ function during severe infections, there is no sufficient therapy for stabilization of endothelial barrier function. Endogenous peptide adrenomedullin (AM) serum levels were shown to be increased during severe infection including sepsis and septic shock. In different in-vitro and in-vivo models AM acted as a potent therapeutic endothelial barrier function-stabilizing agent. Activation of specific receptors by AM results in elevation of second messenger cAMP. AM inhibits actin-myosin based endothelial cell contraction and junctional disassembly, thereby preventing paracellular permeability and oedema formation. The peptide furthermore possesses several protective cardiovascular qualities, including protection of the microcirculation during inflammation, and was proven as an efficient counter-regulatory molecule in various models of sepsis and septic shock. Overall, AM may be an attractive molecule to combat against cardiovascular malfunction during severe infection.

Topics: Adrenomedullin; Cardiotonic Agents; Endothelium, Vascular; Humans; Inflammation; Permeability; Sepsis

This review summarizes the receptor-mediated vascular activities of calcitonin gene-related peptide (CGRP) and the structurally related peptide adrenomedullin (AM). CGRP is a 37-amino acid neuropeptide, primarily released from sensory nerves, whilst AM is produced by stimulated vascular cells, and amylin is secreted from the pancreas. They share vasodilator activity, albeit to varying extents depending on species and tissue. In particular, CGRP has potent activity in the cerebral circulation, which is possibly relevant to the pathology of migraine, whilst vascular sources of AM contribute to dysfunction in cardiovascular disease. Both peptides exhibit potent activity in microvascular beds. All three peptides can act on a family of CGRP receptors that consist of calcitonin receptor-like receptor (CL) linked to one of three receptor activity-modifying proteins (RAMPs) that are essential for functional activity. The association of CL with RAMP1 produces a CGRP receptor, with RAMP2 an AM receptor and with RAMP3 a CGRP/AM receptor. Evidence for the selective activity of the first nonpeptide CGRP antagonist BIBN4096BS for the CGRP receptor is presented. The cardiovascular activity of these peptides in a range of species and in human clinical conditions is detailed, and potential therapeutic applications based on use of antagonists and gene targeting of agonists are discussed.

Topics: Adrenomedullin; Amino Acid Sequence; Animals; Blood Vessels; Calcitonin Gene-Related Peptide; Cardiovascular Diseases; Humans; Inflammation; Microcirculation; Molecular Sequence Data; Peptides; Receptors, Adrenomedullin; Receptors, Calcitonin Gene-Related Peptide; Receptors, Peptide; Tissue Distribution; Vasodilation

Adrenomedullin (AM) is a peptide that possesses potentially beneficial properties. Since the initial discovery of the peptide by Kitamura et al. in 1993, the literature has been awash with reports describing its novel mechanisms of action and huge potential as a therapeutic target. Strong evidence now exists that AM is able to act as an autocrine, paracrine, or endocrine mediator in a number of biologically significant functions, including the endothelial regulation of blood pressure, protection against organ damage in sepsis or hypoxia, and the control of blood volume through the regulation of thirst. Its early promise as a potential mediator/modulator of disease was not, however, entirely as a result of the discovery of physiological functions but due more to the observation of increasing levels measured in plasma in direct correlation with disease progression. In health, AM circulates at low picomolar concentrations in plasma in 2 forms, a mature 52-amino acid peptide and an immature 53-amino acid peptide. Plasma levels of AM have now been shown to be increased in a number of pathological states, including congestive heart failure, sepsis, essential hypertension, acute myocardial infarction, and renal impairment. These earliest associations have been further supplemented with evidence of a role for AM in other pathologies including, most intriguingly, cancer. In this review, we offer a timely review of our current knowledge on AM and give a detailed account of the putative role of AM in those clinical areas in which the best therapeutic opportunities might exist.

Topics: Adrenomedullin; Animals; Cardiovascular Diseases; Clinical Trials as Topic; Diabetes Mellitus; Humans; Inflammation; Kidney Diseases; Neoplasms; Neovascularization, Pathologic; Peptides; Sepsis

The upregulation of adrenomedullin (AM) gene expression and increases in systemic circulatory as well as localized tissue AM concentrations is well coordinated with the onset and progression of trauma, infection, and sepsis. As such, the coordinated change in AM suggests a key role for this peptide in the inflammatory response. By clinical definition, the process of inflammation constitutes an orchestrated cascade of localized tissue and systemic responses to immunological challenges. Classical responses to the onset of disease stresses are manifested in the timely elaboration of humoral, blood-borne signal effectors (such as adrenocortical and locally produced tissue hormones, immune cytokines, and inorganic signals such as nitric oxide) as well as patterned migration and infiltration of circulating bone marrow-derived cells (mononuclear cells such as monocyte-macrophages and polymorphonuclear cells like neutrophils) largely associated with or delivered through the vascular system. The body's attempts to combat acute infection to restore homeostatic equilibrium are further compromised by underlying disease situations. Atherosclerosis, diabetes, and cardiovascular disease, as well as nutritional metabolic derangements and persistent subclinical infection perturb the regulatory feedback loops necessary for proper control of response effectors like hormones and cytokines. When imbalances occur, tissue necrosis can ensue as driven by free radical damage to cell components. A true appreciation of the inflammatory response can only be grasped through an integrative approach in which the relationship between the different physiological systems is viewed in terms of a changing, dynamic interaction. In essence, the inflammatory response can be thought of in three phases: a period of severity assessment, a period of remediation, and a period of homeostatic restoration. Indeed, AM has differential effects on cellular metabolism, immune function, endocrine function, and cardiovascular function. This peptide appears to play a pivotal role in both reprioritizing the biological needs of tissues and organs during the three phases of inflammatory response as well as a role in restoring homeostatic equilibrium to the body.

Topics: Adrenomedullin; Homeostasis; Humans; Inflammation; Peptides

Adrenomedullin (AM) is a vasodilator peptide first identified in pheochromocytoma tissue, but endothelial cells and vascular smooth muscle cells actively secrete AM in addition to expressing AM receptors. AM dilates blood vessels through its direct action on the smooth muscle and the endothelial cell-mediated nitric oxide pathway. We have further demonstrated that AM is synthesized and secreted from macrophages, fibroblasts, cardiomyocytes and many other types of cells. AM secretion from these cells as well as the vascular wall cells are commonly stimulated with inflammatory cytokines and lipopolysaccharide. AM receptor is also widely distributed, and AM is shown to regulate production of inflammatory cytokines and cell growth. Based on these data, AM is deduced to be a multi-functional peptide participating in the regulation of vascular tone, inflammation and other physiologic events of the vasculature.

Topics: Adrenal Gland Neoplasms; Adrenomedullin; Amino Acid Sequence; Animals; Blood Pressure; Cell Division; Cytokines; Endothelium, Vascular; Fibroblasts; Humans; Inflammation; Lipopolysaccharides; Mice; Mice, Transgenic; Molecular Sequence Data; Muscle, Smooth, Vascular; Neoplasm Proteins; Nitric Oxide; Organ Specificity; Peptides; Pheochromocytoma; Rats; Receptors, Adrenomedullin; Receptors, Peptide; Shock, Septic; Vasodilation

Topics: Adrenomedullin; Animals; Digestive System; Disease Models, Animal; Gene Expression; Humans; Immunohistochemistry; Inflammation; Mice; Peptides; Rats; Reference Values; RNA, Messenger

Heart failure can be associated with inflammation but it is unclear if inflammation is directly related to hemodynamic worsening or is an independent pathway. Our aim was to investigate inflammation and mechanical stress using serial measurements of biomarkers in acute and chronic heart failure with reduced ejection fraction (AHF and CHF).. The following biomarkers were measured on admission, at discharge and one month after discharge: B-type natriuretic peptide (BNP), high-sensitivity C-Reactive protein (hsCRP), Tumour Necrosis Factor alpha (TNFα), interleukin 6 (IL6), myeloperoxidase (MPO), suppression of tumorigenicity 2 (ST2), mid-regional pro-adrenomedullin (MR-proADM), galectin 3 (Gal3), Growth differentiating factor 15 (GDF15) and procalcitonin (PCT).. In control CHF group (n=20, 69±11y, NYHA 1-2), most biomarker levels were low and stable over time. In AHF (n=55, 71±14y), BNP, ST2 and GDF15 levels were highly increased on admission and then decreased rapidly with clinical improvement; BNP, ST2 and GDF15 levels were statistically correlated (r=0.64, 0.46 and 0.39; p<0.001 for both). Both hsCRP, MPO, TNFα and Gal3 levels were increased in most AHF patients (70, 56, 83 and 98% respectively) with poor change over time. HsCRP, MPO and TNFα levels were correlated. IL6, MR-proADM and PCT levels were slightly increased, without change over time. Highest quartiles of BNP and ST2 were associated with death or readmission at one year (HR 2.33 [95CI 1.13-4.80] and 2.42 [1.27-4.60]).. AHF is associated with systemic inflammation. This inflammatory response continued up to one month after discharge despite normalisation of mechanical stress-related markers.

Topics: Adrenomedullin; Aged; Biomarkers; C-Reactive Protein; Female; Follow-Up Studies; Heart Failure; Humans; Inflammation; Inflammation Mediators; Male; Middle Aged; Natriuretic Peptide, Brain; Stroke Volume

Obstructive sleep apnoea (OSA) is associated with cardiovascular disease. Intermittent hypoxia, endothelial dysfunction and adipose tissue-mediated inflammation have all been linked to cardiovascular disease in OSA. We therefore explored the effect of OSA on relevant associated blood markers: adrenomedullin (ADM), endocan, endothelin-1 (ET-1), resistin and vascular endothelial growth factor (VEGF).. Patients with OSA, established on and compliant with continuous positive airways pressure (CPAP) therapy for >1 year were included from three randomized controlled trials, conducted at two centres. Patients were randomized to either continued therapeutic CPAP or sham CPAP (CPAP withdrawal) for 2 weeks. Blood markers were measured at baseline and at 14 days and the treatment effect between sham CPAP and therapeutic CPAP was analysed.. A total of 109 patients were studied (therapeutic CPAP n = 54, sham CPAP n = 55). Sham CPAP was associated with a return of OSA (between-group difference in oxygen desaturation index (ODI) 36.0/h, 95% CI 29.9-42.2, P < 0.001). Sham CPAP was associated with a reduction in ADM levels at 14 days (-26.0 pg/mL, 95% CI -47.8 to -4.3, P = 0.02), compared to therapeutic CPAP. Return of OSA was not associated with changes in endocan, ET-1, resistin or VEGF.. Whilst CPAP withdrawal was associated with return of OSA, it was associated with an unexpected significant reduction in the vasodilator ADM and not with expected increases in hypoxia-induced markers, markers of endothelial function or resistin. We propose that the vascular effects occurring in OSA may be brought about by other mechanisms, perhaps partly through a reduction in ADM.

Topics: Adrenomedullin; Adult; Aged; Biomarkers; Continuous Positive Airway Pressure; Endothelin-1; Female; Humans; Hypoxia; Inflammation; Male; Middle Aged; Neoplasm Proteins; Patient Compliance; Proteoglycans; Resistin; Sleep Apnea, Obstructive; Vascular Endothelial Growth Factor A; Ventilator Weaning

Adrenomedullin (ADM) is a novel cardiovascular peptide with anti-inflammatory and antioxidant properties. Chronic inflammation, oxidative stress and calcification play pivotal roles in the pathogenesis of vascular dysfunction in obesity-related hypertension (OH). Our study aimed to explore the effects of ADM on the vascular inflammation, oxidative stress and calcification in rats with OH. Eight-week-old Sprague Dawley male rats were fed with either a Control diet or a high fat diet (HFD) for 28 weeks. Next, the OH rats were randomly subdivided into two groups as follows: (1) HFD control group, and (2) HFD with ADM. A 4-week treatment with ADM (7.2 μg/kg/day, ip) not only improved hypertension and vascular remodeling, but also inhibited vascular inflammation, oxidative stress and calcification in aorta of rats with OH. In vitro experiments, ADM (10 nM) in A7r5 cells (rat thoracic aorta smooth muscle cells) attenuated palmitic acid (PA, 200 μM) or angiotensin II (Ang II, 10 nM) alone or their combination treatment-induced inflammation, oxidative stress and calcification, which were effectively inhibited by the ADM receptor antagonist ADM22-52 and AMP-activated protein kinase (AMPK) inhibitor Compound C, respectively. Moreover, ADM treatment significantly inhibited Ang II type 1 receptor (AT1R) protein expression in aorta of rats with OH or in PA-treated A7r5 cells. ADM improved hypertension, vascular remodeling and arterial stiffness, and attenuated inflammation, oxidative stress and calcification in OH state partially via receptor-mediated AMPK pathway. The results also raise the possibility that ADM will be considered for improving hypertension and vascular damage in patients with OH.

Topics: Adrenomedullin; AMP-Activated Protein Kinases; Animals; Anti-Inflammatory Agents; Antioxidants; Calcinosis; Hypertension; Inflammation; Male; Obesity; Rats; Rats, Sprague-Dawley; Vascular Remodeling

Adrenomedullin 2 (AM2; also known as intermedin) is a member of the adrenomedullin (AM) peptide family. Similarly to AM, AM2 partakes in a variety of physiological activities. AM2 has been reported to exert protective effects on various organ disorders; however, its significance in the eye is unknown. We investigated the role of AM2 in ocular diseases. The receptor system of AM2 was expressed more abundantly in the choroid than in the retina. In an oxygen-induced retinopathy model, physiological and pathologic retinal angiogenesis did not differ between AM2-knockout (AM2-/-) and wild-type mice. In contrast, in laser-induced choroidal neovascularization, a model of neovascular age-related macular degeneration, AM2-/- mice had enlarged and leakier choroidal neovascularization lesions, with exacerbated subretinal fibrosis and macrophage infiltration. Contrary to this, exogenous administration of AM2 ameliorated the laser-induced choroidal neovascularization-associated pathology and suppressed gene expression associated with inflammation, fibrosis, and oxidative stress, including that of VEGF-A, VEGFR-2, CD68, CTGF, and p22-phox. The stimulation of human adult retinal pigment epithelial (ARPE) cell line 19 cells with TGF-β2 and TNF-α induced epithelial-to-mesenchymal transition (EMT), whereas AM2 expression was also elevated. The induction of EMT was suppressed when the ARPE-19 cells were pretreated with AM2. A transcriptome analysis identified 15 genes, including mesenchyme homeobox 2 (Meox2), whose expression was significantly altered in the AM2-treated group compared with that in the control group. The expression of Meox2, a transcription factor that inhibits inflammation and fibrosis, was enhanced by AM2 treatment and attenuated by endogenous AM2 knockout in the early phase after laser irradiation. The AM2 treatment of endothelial cells inhibited endothelial to mesenchymal transition and NF-κB activation; however, this effect tended to be canceled following Meox2 gene knockdown. These results indicate that AM2 suppresses the neovascular age-related macular degeneration-related pathologies partially via the upregulation of Meox2. Thus, AM2 may be a promising therapeutic target for ocular vascular diseases.

Topics: Adrenomedullin; Animals; Choroidal Neovascularization; Endothelial Cells; Fibrosis; Humans; Inflammation; Macular Degeneration; Mice; Neuropeptides

White adipose tissue (WAT) dysfunction has been associated with adipose tissue low-grade inflammation and oxidative stress leading to insulin resistance (IR). Adrenomedullin (ADM), an endogenous active peptide considered as an adipokine, is associated with adipocytes function.. We evaluated the protective effects of ADM against IR in 3T3-L1 adipocytes treated by palmitic acid (PA) and in visceral white adipose tissue (vWAT) of obese rats fed with high-fat diet.. We found that endogenous protein expressions of ADM and its receptor in PA-treated adipocytes were markedly increased. PA significantly induced impaired insulin signaling by affecting phosphatidylinositol 3-kinase (PI3K)-protein kinase B (Akt) axis and glucose transporter-4 (GLUT-4) levels, whereas ADM pretreatment enhanced insulin signaling PI3K/Akt and GLUT-4 membrane protein levels, decreased pro-inflammatory cytokines tumor necrosis factor α (TNFα), interleukin-1β (IL-1β) and IL-6 levels, and improved oxidative stress accompanied with reduced reactive oxygen species (ROS) levels and increased anti-oxidant enzymes manganese superoxide dismutase 2 (SOD2), glutathione peroxidase (GPx1) and catalase (CAT) protein expressions. Furthermore, ADM treatment not only improved IR in obese rats, but also effectively restored insulin signaling, and reduced inflammation and oxidative stress in vWAT of obese rats.. This study demonstrates a prevention potential of ADM against obesity-related metabolic disorders, due to its protective effects against IR, inflammation and oxidative stress in adipocytes.

Topics: Adipocytes; Adrenomedullin; Animals; Inflammation; Insulin; Insulin Resistance; Obesity; Palmitic Acid; Phosphatidylinositol 3-Kinase; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Rats

Despite its vasodilatory effect, adrenomedullin and its surrogate mid-regional pro-adrenomedullin (MR-proADM) have been found to be positively associated with all-cause and cardiovascular mortality. However, the underlying mechanisms thereof remain unclear and the associations were mostly shown in geriatric cohorts or in patients with chronic diseases. Therefore, we aimed to investigate the possible involvement of abdominal obesity, selected adipokines, and biomarkers of subclinical inflammation in the association of MR-proADM with mortality in a population based study cohort.. Prospective analysis of the KORA F4 study; median follow-up 9.1 (8.8-9.4) years. Complete data on MR-proADM and mortality was available for 1551 participants, aged 56.9±12.9 years (mean±SD). Correlation and regression analyses of MR-proADM with overall (BMI) and abdominal obesity (waist circumference), selected adipokines and biomarkers of subclinical inflammation. Cox proportional hazard models on the association of MR-proADM with all-cause and cardiovascular mortality with adjustment for cardiovascular risk factors and selected biomarkers in study subgroups (n = 603-1551).. MR-proADM associated with all-cause (HR (95%CI): 2.37 (1.72-3.26) and 2.31 (1.67-3.20)) and cardiovascular mortality (4.28 (2.19-8.39) and 4.44 (2.25-8.76)) after adjustment for traditional cardiovascular risk factors including BMI or waist circumference, respectively. MR-proADM was further associated with four out of seven examined adipokines (leptin, retinol-binding protein-4, chemerin, and adiponectin) and with five out of eleven examined biomarkers of subclinical inflammation (high-sensitivity C-reactive protein, interleukin-6, myeloperoxidase, interleukin-22, and interleukin-1 receptor antagonist) after multivariable adjustment and correction for multiple testing. However, only IL-6 substantially attenuated the association of MR-proADM with all-cause mortality.. We found an association of MR-proADM with (abdominal) obesity, selected adipokines, and biomarkers of subclinical inflammation. However, the association of MR-proADM with mortality was independent of these parameters. Future studies should investigate the role of IL-6 and further characteristics of subclinical inflammation in the association between MR-proADM and all-cause mortality.

Topics: Adrenomedullin; Biomarkers; Cardiovascular Diseases; Cardiovascular System; Female; Humans; Inflammation; Male; Middle Aged; Obesity; Peptide Fragments; Prospective Studies; Protein Precursors; Risk Factors

Hypoxia contributes to airway inflammation and remodeling in several lung diseases; however, exactly how hypoxic pulmonary epithelium regulates allergic inflammation remains to be fully characterized. Here, we report that conditional deletion of the E3 ubiquitin ligase VHL in lung epithelial cells resulted in exacerbated type 2 responses accompanied by selective increase of group 2 innate lymphoid cells (ILC2s) at steady state and following inflammation or helminth infection. Ablation of expression of the hypoxia-inducible factor 2α (HIF2α) significantly reversed VHL-mediated ILC2 activation. VHL deficiency in lung epithelial cells caused increased expression of the peptide hormone adrenomedullin (ADM), and our data suggest that HIF2α controls Adm expression. ADM directly promoted ILC2 activation both in vitro and in vivo. Our findings indicate that the hypoxic response mediated by the VHL-HIF2α axis is critical for control of pulmonary type 2 responses by increasing ADM expression in lung epithelia, causing ILC2 activation.

Topics: Adrenomedullin; Epithelium; Humans; Hypoxia; Immunity, Innate; Inflammation; Lung; Lung Diseases; Lymphocytes

Doxorubicin (DOX) is an anticancer antibiotic which has various effects in human cancers. It is one of the commonly known causes of drug-induced nephrotoxicity, which results in acute renal injury. Adrenomedullin (ADM), a vasodilator peptide, is widely distributed in many tissues and has potent protective effects. Therefore, the current study aimed to examine the protective potential mechanisms of ADM against DOX-induced nephrotoxicity. A total of 28 male Wistar rats were randomized into four groups: control group, doxorubicin group (15 mg/kg single intraperitoneal injection of DOX), adrenomedullin + doxorubicin group (12 μg/kg/day intraperitoneal injection of ADM) 3 days prior to DOX injection and continuing for 14 days after the model was established, and adrenomedullin group. Kidney function biomarkers, oxidative stress markers, and inflammatory mediators (TNF-α, NLRP3, IL-1β, and IL-18) were assessed. The expressions of gasdermin D and ASC were assessed by real-time PCR. Furthermore, the abundances of caspase-1 (p20), Bcl-2, and Bax immunoreactivity were evaluated. ADM administration improved the biochemical parameters of DOX-induced nephrotoxicity, significantly reduced oxidative damage markers and inflammatory mediators, and suppressed both apoptosis and pyroptosis. These results were confirmed by the histopathological findings and revealed that ADM's antioxidant, anti-inflammatory, anti-apoptotic, and anti-pyroptotic properties may have prospective applications in the amelioration of DOX-induced nephrotoxicity.

Topics: Adrenomedullin; Animals; Apoptosis; Doxorubicin; Inflammation; Inflammation Mediators; Male; Oxidative Stress; Pyroptosis; Rats; Rats, Wistar; Renal Insufficiency

Thromboinflammation, resulting from a complex interaction between thrombocytopathy, coagulopathy, and endotheliopathy, contributes to increased mortality in COVID-19 patients. MR-proADM, as a surrogate of adrenomedullin system disruption, leading to endothelial damage, has been reported as a promising biomarker for short-term prognosis. We evaluated the role of MR-proADM in the mid-term mortality in COVID-19 patients.. A prospective, observational study enrolling COVID-19 patients from August to October 2020. A blood sample for laboratory test analysis was drawn on arrival in the emergency department. The primary endpoint was 90-day mortality. The area under the curve (AUC) and Cox regression analyses were used to assess discriminatory ability and association with the endpoint.. A total of 359 patients were enrolled, and the 90-day mortality rate was 8.9%. ROC AUC for MR-proADM predicting 90-day mortality was 0.832. An optimal cutoff of 0.80 nmol/L showed a sensitivity of 96.9% and a specificity of 58.4%, with a negative predictive value of 99.5%. Circulating MR-proADM levels (inverse transformed), after adjusting by a propensity score including eleven potential confounders, were an independent predictor of 90-day mortality (HR: 0.162 [95% CI: 0.043-0.480]) CONCLUSIONS: Our data confirm that MR-proADM has a role in the mid-term prognosis of COVID-19 patients and might assist physicians with risk stratification.

Topics: Adrenomedullin; Biomarkers; COVID-19; Humans; Inflammation; Prognosis; Prospective Studies; Protein Precursors; Risk Assessment; SARS-CoV-2; Thrombosis

Gout is a local inflammatory disease caused by the deposition of monosodium urate (MSU) crystals in joints or adjacent tissues. When some gout occurs without hyperuricemia, or its clinical symptoms and signs are not typical, the diagnosis of gout will be delayed, so there is an urgent need to find a new biomarker to predict and diagnose of gout flare. Our research attempts to find the key genes and potential molecular mechanisms of gout through bioinformatics analysis, and collected general data and blood biochemical samples of patients with gout and healthy, then analyzed and compared the expression of factors regulated by key genes.. GSE160170 were downloaded from GEO database for analysis. The data were normalized to identify the differentially expressed genes (DEGs), then GO and KEGG enrichment analysis were applied. Protein-protein interaction (PPI) networks and hub genes between DEGs were identified. Then collect general information and blood samples from male patients with acute gout, hyperuricemia and healthy. ELISA method was used to detect pro-ADM levels of different groups, and the data was input into SPSS statistical software for analysis.. We identified 266 DEGs (179 up-regulated and 87 down-regulated) between gout patients and healthy controls. GO analysis results show that DEGs are mostly enriched in inflammatory response, growth factor activity, cytokine activity, chemokine activity, S100 protein binding and CXCR chemokine receptor binding. KEGG pathway analysis showed that DEGs are mainly related to Chemokine signaling pathway and Cytokine-cytokine receptor interaction. ADM, CXCR1, CXCR6, CXCL3, CCL3, CCL18, CCL3L3, CCL4L1, CD69, CD83, AREG, EREG, B7RP1, HBEGF, NAMPT and S100B are the most important hub genes in the PPI network. We found that the expression of pro-ADM in the gout group and hyperuricemia group was higher than that in the healthy group, and the difference was statistically significant.. In this study, a series of bioinformatics analyses were performed on DEGs to identify key genes and pathways related to gout. Through clinical verification, we found that pro-ADM can be used as an inflammation-related biomarker for acute attacks of gout, providing new ideas for the diagnosis and treatment of gout.

Topics: Adrenomedullin; Adult; Biomarkers; Computational Biology; Databases, Genetic; Enzyme-Linked Immunosorbent Assay; Gene Expression Profiling; Gene Ontology; Gene Regulatory Networks; Gout; Humans; Inflammation; Male; Protein Interaction Maps; Protein Precursors; Signal Transduction

Adrenomedullin (ADM) possesses therapeutic potential for inflammatory diseases. Consequently, the effects of ADM on inflammation in visceral white adipose tissue (vWAT) of obese rats or in adipocytes were explored in this study.. Male rats were fed a high-fat diet for 12 weeks to induce obesity, and obese rats were implanted with osmotic minipumps providing constant infusion of ADM (300 ng/kg per hour) and continued to be fed a high-fat diet for 4 weeks.. When compared with the control group, endogenous protein expression of ADM and ADM receptors in vWAT and in lipopolysaccharide (LPS)-treated adipocytes was markedly increased. ADM significantly decreased the protein expression of the inflammatory mediators TNFα, IL-1β, cyclooxygenase-2, and inducible nitric oxide synthase in vWAT of obese rats and in adipocytes stimulated by LPS. It also inhibited the activation of the inflammatory signaling pathways MAPK and NF-κB induced by LPS in adipocytes. These effects of ADM in adipocytes were inhibited by the administration of ADM receptor antagonist and cAMP-dependent protein kinase (PKA) activation inhibitor.. ADM can inhibit inflammation in WAT in obesity, which may be mediated by the activation of ADM receptors and PKA.

Topics: 3T3 Cells; Adipocytes; Adipose Tissue, White; Adrenomedullin; Animals; C-Reactive Protein; Cyclooxygenase 2; Diet, High-Fat; Inflammation; Inflammation Mediators; Interleukin-1beta; Male; Mice; NF-kappa B; Nitric Oxide Synthase Type II; Obesity; Rats; Rats, Sprague-Dawley; Receptors, Adrenomedullin; Signal Transduction; Tumor Necrosis Factor-alpha

Early identification of patients at high risk of progression to severe COVID-19 constituted an unsolved challenge. Although growing evidence demonstrates a direct association between endotheliitis and severe COVID-19, the role of endothelial damage biomarkers has been scarcely studied. We investigated the relationship between circulating mid-regional proadrenomedullin (MR-proADM) levels, a biomarker of endothelial dysfunction, and prognosis of SARS-CoV-2-infected patients.. Prospective observational study enrolling adult patients with confirmed COVID-19. On admission to emergency department, a blood sample was drawn for laboratory test analysis. Primary and secondary endpoints were 28-day all-cause mortality and severe COVID-19 progression. Area under the curve (AUC) and multivariate regression analysis were employed to assess the association of the biomarker with the established endpoints.. A total of 99 patients were enrolled. During hospitalization, 25 (25.3%) cases progressed to severe disease and the 28-day mortality rate was of 14.1%. MR-proADM showed the highest AUC to predict 28-day mortality (0.905; [CI] 95%: 0.829-0.955; P < .001) and progression to severe disease (0.829; [CI] 95%: 0.740-0.897; P < .001), respectively. MR-proADM plasma levels above optimal cut-off (1.01 nmol/L) showed the strongest independent association with 28-day mortality risk (hazard ratio [HR]: 10.470, 95% CI: 2.066-53.049; P < .005) and with progression to severe disease (HR: 6.803, 95% CI: 1.458-31.750; P = .015).. Mid-regional proadrenomedullin was the biomarker with highest performance for prognosis of death and progression to severe disease in COVID-19 patients and represents a promising predictor for both outcomes, which might constitute a potential tool in the assessment of prognosis in early stages of this disease.

Topics: Adrenomedullin; Aged; Aged, 80 and over; Area Under Curve; Cause of Death; COVID-19; Disease Progression; Endothelium, Vascular; Female; Humans; Inflammation; Intensive Care Units; Male; Middle Aged; Mortality; Peptide Fragments; Prognosis; Proportional Hazards Models; Prospective Studies; Protein Precursors; Respiration, Artificial; SARS-CoV-2; Severity of Illness Index

Proadrenomedullin N-terminal 20 peptide (PAMP) is elevated in sepsis, but the function and possible mechanism of PAMP in bacterial infection is elusive. This study is aim to evaluate the role of PAMP in the interaction between the Enterohemorrhagic E. coli (EHEC) and the host barrier. Our results showed that PAMP alleviated the EHEC-induced disruption of goblet cells and mucosal damage in the intestine, increased the expression of occludin in the colon of EHEC-infected mice, and reduced the proinflammatory cytokines level in serum significantly compared with the control group. Meanwhile, lipopolysaccharide (LPS) stimulation could dose-dependently induce the expression of preproADM, the precursor of PAMP, in human intestinal epithelial cell (HIEC) and human umbilical vein endothelial cell (HUVEC). In addition, PAMP inhibited the growth of EHEC O157:H7 and destroyed the inner and outer membrane. At low concentration, PAMP attenuated the EHEC virulence genes including hlyA and eaeA, which was also confirmed from reduced hemolysis to red cells and adhesion to HIEC. These results indicated that EHEC infection would modulate the expression of PAMP in intestinal epithelium or vascular endothelium, and in turn exerted a protective effect in EHEC induced infection by rupturing the bacterial cell membrane and attenuating the bacterial virulence.

Topics: Adrenomedullin; Amino Acid Sequence; Animals; Anti-Infective Agents; Cell Membrane; Cytokines; Enterohemorrhagic Escherichia coli; Escherichia coli Infections; Gene Expression Regulation; Human Umbilical Vein Endothelial Cells; Humans; Inflammation; Inflammation Mediators; Intestines; Lipopolysaccharides; Male; Mice, Inbred C57BL; Protective Agents; Virulence

Topics: Adrenomedullin; Heart Failure; Humans; Inflammation; Sepsis; Shock, Septic

Topics: Adrenomedullin; Heart Failure; Humans; Inflammation; Sepsis; Shock, Septic

Topics: Adrenomedullin; Coronavirus Infections; COVID-19; COVID-19 Drug Treatment; Endothelium; Humans; Inflammation; Pandemics; Pneumonia, Viral

BACKGROUND Chinese hawthorn (Crataegus pinnatifida) fruit is a traditional Chinese medicine for treatment of digestive system and cardiovascular diseases. The fruit contains polyphenol compounds, such as epicatechin, that have anti-inflammatory activity. This study aimed to investigate the effects of an alcohol extract of hawthorn fruit (HAE) on inflammation and oxidative stress in rats with doxorubicin-induced chronic heart failure (CHF). MATERIAL AND METHODS Rats were intraperitoneally injected with doxorubicin to induce CHF and subsequently treated with HAE intragastrically once daily for 6 weeks. At the end of the experiment, echocardiographic and hemodynamic parameters were assessed, and enzyme-linked immunoassays were used to detect the levels of cardiac injury markers (brain natriuretic peptide, creatine kinase-MB, aspartate aminotransferase, lactate dehydrogenase, copeptin, and adrenomedullin), oxidative stress markers (glutathione peroxidase and malondialdehyde), and inflammatory cytokines (interleukin [IL]-6, IL-8, IL-1ß, and tumor necrosis factor-a). The IL-1ß, IL-6, glutathione peroxidase-1, and catalase mRNA levels were also measured by quantitative real-time polymerase chain reaction. RESULTS Our findings indicated that HAE exerts a cardioprotective effect, as shown by improved echocardiographic and hemodynamic parameters, decreased activity of serum myocardial enzymes, reduced serum levels of CHF markers, and inhibited inflammatory response in cardiac tissue. In addition, HAE treatment downregulated the mRNA expression of IL-1ß and tumor necrosis factor-alpha and upregulated the mRNA expression of glutathione peroxidase-1 and catalase compared with untreated doxorubicin-induced CHF rats. CONCLUSIONS HAE shows promise for the prevention and treatment of CHF. The cardioprotective effect of HAE appears to be related to inhibition of both the inflammatory response and oxidative stress in vivo.

Topics: Adrenomedullin; Animals; Antioxidants; Aspartate Aminotransferases; Chromatography, High Pressure Liquid; Chronic Disease; Crataegus; Creatine Kinase; Cytokines; Doxorubicin; Electrocardiography; Ethanol; Fruit; Glutathione Peroxidase; Glycopeptides; Heart Failure; Heart Function Tests; Inflammation; L-Lactate Dehydrogenase; Male; Malondialdehyde; Natriuretic Peptide, Brain; Oxidative Stress; Plant Extracts; Polyphenols; Rats, Wistar; RNA, Messenger

Atherosclerosis develops preferentially in areas of the arterial system, in which blood flow is disturbed. Exposure of endothelial cells to disturbed flow has been shown to induce inflammatory signaling, including NF-κB activation, which leads to the expression of leukocyte adhesion molecules and chemokines. Here, we show that disturbed flow promotes the release of adrenomedullin from endothelial cells, which in turn activates its Gs-coupled receptor calcitonin receptor-like receptor (CALCRL). This induces antiinflammatory signaling through cAMP and PKA, and it results in reduced endothelial inflammation in vitro and in vivo. Suppression of endothelial expression of Gαs, the α subunit of the G-protein Gs; CALCRL; or adrenomedullin leads to increased disturbed flow-induced inflammatory signaling in vitro and in vivo. Furthermore, mice with induced endothelial-specific deficiency of Gαs, CALCRL, or adrenomedullin show increased atherosclerotic lesions. Our data identify an antiinflammatory signaling pathway in endothelial cells stimulated by disturbed flow and suggest activation of the endothelial adrenomedullin/CALCRL/Gs system as a promising approach to inhibit progression of atherosclerosis.

Topics: Adrenomedullin; Animals; Atherosclerosis; Blood Circulation; Calcitonin Receptor-Like Protein; Cattle; Cell Adhesion Molecules; Endothelial Cells; Endothelium, Vascular; Human Umbilical Vein Endothelial Cells; Humans; Inflammation; Mice; NF-kappa B; Primary Cell Culture; Signal Transduction; Vascular Cell Adhesion Molecule-1

Adrenomedullin (AM) is a pluripotent peptide hormone with contradictory effects in human health and disease. In chronic inflammatory lung diseases, such as asthma and COPD, AM has been shown to inhibit inflammation and cell proliferation. In the present study, we aimed to investigate the effect of AM on pro-angiogenic and pro-inflammatory cytokines in asthma and COPD.. Serum levels of pro-AM were measured in patients with asthma, COPD and matched controls. The effect of AM on intracellular signaling proteins and cytokine secretion was assessed in primary cultures of epithelial cells (EC) and airway smooth muscle cells (ASMC) established from endo-bronchial biopsies of patients with asthma, COPD and controls.. Serum pro-AM was higher in patients with asthma and COPD, compared to controls. AM stimulated cAMP in ASMC but not in EC. In EC, AM decreased Erk1/2 MAPK expression and activation but in ASMC, AM activated Erk1/2. This effect was similar in asthma, COPD and controls. AM stimulated the secretion of pro-angiogenic CXCL1 by EC of controls and CXCL5 by EC of asthma patients. AM did not affect the secretion of IL-6 or IL-8 by EC but stimulated the secretion of IL-6 by ASMC. In EC, AM inhibited the stimulatory effect of TGF-β and IL-4 on the secretion of IL-6 and IL-8 but had an additive stimulatory effect with TGF-β in ASMC.. These data suggest that AM mediates the secretion of pro-angiogenic and pro-inflammatory cytokines in a cell-type and/or a disease-specific way, explaining its association with clinical outcomes in COPD.

Topics: Adrenomedullin; Aged; Asthma; Cells, Cultured; Cytokines; Epithelial Cells; Female; Humans; Inflammation; Male; Middle Aged; Myocytes, Smooth Muscle; Neovascularization, Physiologic; Pulmonary Disease, Chronic Obstructive

Human adrenomedullin (hAM) is a hypotensive peptide hormone that exerts powerful anti-inflammatory effects. However, treatment required continuous administration of hAM, as the half-life of native hAM is quite short in blood. To resolve this problem, we designed two kinds of human IgG1 Fc fusion proteins containing either full-length hAM (IgG1-AM) or hAM residues 6-52 [IgG1-AM (6-52)]. A DNA construct was constructed by connecting DNA sequences encoding hAM and the IgG1 Fc region with a DNA sequence encoding a (GGGGS)3 linker. The molecular weights of IgG1-AM and IgG1-AM (6-52) were determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and gel filtration chromatography. By protein sequencing, the N-terminal sequence of both recombinant AM-Fc fusions showed the expected human IgG1 sequence. Sufficient concentrations of both AM-Fc fusions were observed in blood 2 days after a single subcutaneous administration. IgG1-AM and IgG1-AM (6-52) stimulated cAMP production in human embryonic kidney-293 cells stably expressing the AM1 receptor. The activity of IgG1-AM (6-52) was higher than that of IgG1-AM. Treatment with IgG1-AM (6-52) inhibited blood pressure increase in spontaneously hypertensive rats. In addition, IgG1-AM (6-52) reduced total inflammation scores in the dextran sulfate sodium colitis model. Therefore, AM-IgG1 Fc fusions represent potential novel therapeutic agents.

Topics: Adrenomedullin; Animals; Cells, Cultured; Colitis; Dextran Sulfate; Disease Models, Animal; HEK293 Cells; Humans; Immunoglobulin Fc Fragments; Immunoglobulin G; Inflammation; Male; Protein Folding; Rats; Rats, Inbred SHR; Rats, Wistar; Recombinant Proteins

Adrenomedullin (ADM) is an important regulator of endothelial barrier function during sepsis. Administration of a murine antibody targeted against the N-terminus of ADM (HAM1101) resulted in improved outcome in models of murine sepsis. We studied the effects of a humanized form of this antibody (HAM8101, also known as Adrecizumab) on vascular barrier dysfunction and survival in rodent models of systemic inflammation and sepsis.. Rats (n=48) received different dosages of HAM8101 or placebo (n = 8 per group), directly followed by administration of lipopolysaccharide (5 mg/kg). Twenty-four hours later, Evans Blue dye was administered to assess vascular leakage in kidney and liver tissue. Furthermore, mice (n = 24) were administered different dosages of HAM8101 or placebo (n = 6 per group), immediately followed by cecal ligation and puncture (CLP). Eighteen hours later, albumin, vascular endothelial growth factor (VEGF), and angiopoietin-1 were analyzed in the kidney. Finally, effects of single and repeated dose administration of HAM1101, HAM8101 and placebo on survival were assessed in CLP-induced murine sepsis (n = 60, n = 10 per group).. Dosages of 0.1 and 2.5 mg/kg HAM8101 attenuated renal albumin leakage in endotoxemic rats. Dosages of 0.1, 2.0, and 20 mg/kg HAM8101 reduced renal concentrations of albumin and the detrimental protein VEGF in septic mice, whereas concentrations of the protective protein angiopoietin-1 were augmented. Both single and repeated administration of both HAM1101 and HAM8101 resulted in improved survival during murine sepsis.. Pretreatment with the humanized anti-ADM antibody HAM8101 improved vascular barrier function and survival in rodent models of systemic inflammation and sepsis.

Topics: Adrenomedullin; Animals; Antibodies; Antibodies, Monoclonal, Humanized; Cecum; Inflammation; Kidney; Ligation; Male; Mice; Punctures; Rats; Rats, Wistar; Sepsis

Impaired maternal lipid metabolism in gestational diabetes mellitus (GDM) has detrimental effects on maternal health and fetal growth. We previously reported the excessive expression of adrenomedullin (ADM) and its receptors in GDM adipose tissues compared with normal glucose-tolerant pregnancies. In the present study, we determined the mechanisms underlying enhanced expression of ADM and its receptors.. Omental adipose tissue (OAT) samples were collected from women during cesarian section of term pregnancy with nonoverweight (NOW; n = 9), overweight (OW; n = 8), obese (OBS; n = 10), and GDM (n = 10) status.. The expression of ADM and its receptors was greater in OATs from GDM than from women who were NOW, OW, and OBS. The expression of adipokines, leptin, and resistin were significantly increased, but adiponectin was decreased in OATs from patients with GDM compared with those without GDM. Macrophage infiltration and TNF-α expression were greater in OAT from pregnant women with GDM than in pregnant women without GDM. Furthermore, TNF-α dose dependently increased mRNA for ADM and its receptor components calcitonin receptor-like receptor and receptor activity-modifying proteins 2 and 3 in OAT explants from women who were NOW. Human adipocytes treated with ADM significantly increased glycerol release in culture medium, and the increases of glycerol in culture medium of OAT from women with GDM were attenuated by ADM antagonists, ADM22-52.. Increased macrophage infiltration and TNF-α expression in adipose tissue from GDM, but not from OBS, tissues stimulate ADM and its receptor overexpression, leading to enhanced lipolysis and hyperlipidemia. This might contribute to fetal macrosomia and adiposity in diabetic pregnancies.

Topics: Adipose Tissue; Adrenomedullin; Adult; Diabetes, Gestational; Dyslipidemias; Female; Fetal Macrosomia; Follow-Up Studies; Humans; Inflammation; Lipids; Lipolysis; Omentum; Pregnancy; Pregnancy Complications; Prenatal Exposure Delayed Effects; Prognosis

Increased adrenomedullin (ADM) levels are associated with various cardiac diseases such as myocardial infarction (MI). ADM is cleaved off from the full-length precursor protein proadrenomedullin (ProADM) during its posttranslational processing. To date, no biological effect of ProADM is reported, while ADM infusion leads to antiapoptotic effects and improved cardiac function. Using an MI mouse model, we found an induction of ProADM gene as well as protein expression during the early phase of MI. This was accompanied by apoptosis and increasing inflammation, which substantially influence the post-MI remodeling processes. Simulating ischemia in vitro, we demonstrate that ProADM expression was increased in cardiomyocytes and cardiac fibroblasts. Subsequently, we treated ischemic cardiomyocytes with either ProADM or ADM and found that both proteins increased survival. This effect was diminishable by blocking the ADM

Topics: Adrenomedullin; Aged; Animals; Apoptosis; Cells, Cultured; Cytokines; Female; Gene Expression; Humans; Inflammation; Inflammation Mediators; Male; Mice, Inbred C57BL; Middle Aged; Myocardial Infarction; Myocytes, Cardiac; Protein Precursors

IgA nephropathy (IgAN) is the most frequent form of glomerulonephritis worldwide. The role of oxidative stress and inflammation in the pathogenesis of IgAN has been reported. Intermedin (IMD) is a newly discovered peptide that is closely related to adrenomedullin. We have recently reported that IMD can significantly reduce renal ischemia/reperfusion injury by diminishing oxidative stress and suppressing inflammation. The present study was designed to explore whether IMD ameliorates IgAN via oxidative stress- and inflammation-dependent mechanisms. Our results showed that IMD administration resulted in the prevention of albuminuria and ameliorated renal pathomorphological changes. These findings were associated with (1) decreased renal TGF-β1 and collagen IV expression, (2) an increased SOD level and reduced MDA level, (3) the inhibition of the renal activation of NF-κB p65 and (4) the downregulation of the expression of inflammatory factors (TNF-α, MCP-1 and MMP-9) in the kidney. These results indicate that IMD in the kidney protects against IgAN by reducing oxidative stress and suppressing inflammation.

Topics: Adrenomedullin; Animals; Glomerulonephritis, IGA; Inflammation; Kidney; Male; Neuropeptides; Oxidative Stress; Rats, Sprague-Dawley; Treatment Outcome

MHC class II (MHCII) antigen presentation in adipocytes was reported to trigger early adipose inflammation and insulin resistance. However, the benefits of MHCII inhibition in adipocytes remain largely unknown. Here, we showed that human plasma polypeptide adrenomedullin 2 (ADM2) levels were negatively correlated with HOMA of insulin resistance in obese human. Adipose-specific human ADM2 transgenic (aADM2-tg) mice were generated. The aADM2-tg mice displayed improvements in high-fat diet-induced early adipose insulin resistance. This was associated with increased insulin signaling and decreased systemic inflammation. ADM2 dose-dependently inhibited CIITA-induced MHCII expression by increasing Blimp1 expression in a CRLR/RAMP1-cAMP-dependent manner in cultured adipocytes. Furthermore, ADM2 treatment restored the high-fat diet-induced early insulin resistance in adipose tissue, mainly via inhibition of adipocyte MHCII antigen presentation and CD4(+) T-cell activation. This study demonstrates that ADM2 is a promising candidate for the treatment of early obesity-induced insulin resistance.

Topics: 3T3-L1 Cells; Adipocytes; Adipose Tissue; Adrenomedullin; Animals; Bone Marrow Transplantation; Cells, Cultured; Genes, MHC Class II; Humans; Inflammation; Insulin Resistance; Mice; Mice, Inbred C57BL; Mice, Transgenic; Models, Biological; Obesity; Peptide Hormones; Positive Regulatory Domain I-Binding Factor 1; Receptor Activity-Modifying Protein 1; Transcription Factors

This study was carried out to investigate whether ADM can modulate LPS-induced inflammation and apoptosis in rat Leydig cells. Leydig cells were treated with ADM before LPS-induced cytotoxicity. We determined the concentrations of ROS, MDA, GSH, LDH, and testosterone and the MMP. The mRNA levels of IL-1, IL-6, iNOS, and COX-2 were obtained, and the concentrations of IL-1, IL-6, NO, and PGE2 were determined. Apoptosis was assessed by TUNEL and detection of DNA fragmentation. The levels of mRNA and protein were determined for Bcl-2, Bax, caspase-3, and PARP. The protein contents for total and p-Akt were measured. ADM pretreatment significantly elevated the MMP and testosterone concentration and reduced the levels of ROS, MDA, GSH, and LDH. ADM pretreatment significantly decreased the mRNA levels of IL-1, IL-6, iNOS, and COX-2 and the concentrations of IL-1, IL-6, NO, and PGE2. LPS-induced TUNEL-positive Leydig cells were significantly decreased by ADM pretreatment, a result further confirmed by decreased DNA fragmentation. ADM pretreatment decreased apoptosis by significantly promoting Bcl-2 and inhibiting Bax, caspase-3, and PARP expressions. The LPS activity that reduced p-Akt level was significantly inhibited by ADM pretreatment. ADM protected rat Leydig cells from LPS-induced inflammation and apoptosis, which might be associated with PI3K/Akt mitochondrial signaling pathway.

Topics: Adrenomedullin; Animals; Apoptosis; Cells, Cultured; Glutathione; Inflammation; Interleukin-1; Interleukin-6; Leydig Cells; Lipopolysaccharides; Male; Malondialdehyde; Membrane Potential, Mitochondrial; Nitric Oxide; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Signal Transduction

The aim of this paper is to investigate the protective effects of adrenomedullin (ADM) on interleukin-1β (IL-1β)-induced inflammation and apoptosis in rat Leydig cells and its underlying molecular mechanisms. Leydig cells were isolated from adult Sprague-Dawley rats. The cell culture was established by adding ADM 2h prior to 24h treatment with IL-1β-induced cytotoxicity. We detected cell viability and concentrations of testosterone, reactive oxygen species (ROS), malondialdehyde (MDA), and reduced glutathione (GSH). Gene expression levels were measured for inducible nitric oxide synthase (iNOS) and cyclo-oxygenase-2 (COX-2). Concentrations were detected for nitric oxide (NO) and prostaglandin E2 (PGE2). Apoptosis was assessed using terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL). Levels of gene expression and protein were detected for Bcl-2, Bax, caspase-3, and poly adenosine diphosphate-ribose polymerase (PARP). Protein levels were measured for nuclear factor kappa B (NF-κB) p65 and IκBα. ADM reduced IL-1β-induced cytotoxicity. ADM pretreatment significantly increased testosterone concentrations and decreased ROS, MDA, and GSH concentrations. ADM pretreatment inhibited IL-1β-induced inflammation in Leydig cells by decreasing the gene expression levels of iNOS and COX-2, as well as the concentrations of NO and PGE2. ADM pretreatment further decreased the number of TUNEL-positive stained Leydig cells, as confirmed by the increase in gene expression and protein levels of Bcl-2 and the decrease of Bax, caspase-3, and PARP levels. Moreover, ADM pretreatment inhibited NF-κB p65 phosphorylation and IκBα phosphorylation and degradation. ADM has potential anti-inflammatory and anti-apoptotic properties in IL-1β-induced rat Leydig cells, which might be related to NF-κB signaling pathway.

Topics: Adrenomedullin; Animals; Apoptosis; Cell Survival; Cells, Cultured; Dose-Response Relationship, Drug; Inflammation; Interleukin-1beta; Leydig Cells; Male; NF-kappa B; Rats; Rats, Sprague-Dawley; Signal Transduction; Structure-Activity Relationship

First reported as a vasoactive peptide in the cardiovascular system, intermedin (IMD), also known as adrenomedullin 2 (ADM2), is a hormone with multiple potent roles, including its antioxidant action on the pulmonary, central nervous, cardiovascular and renal systems. Though IMD may play certain roles in trophoblast cell invasion, early embryonic development and cumulus cell-oocyte interaction, the role of IMD in the male reproductive system has yet to be investigated. This paper reports our findings on the gene expression of IMD, its receptor components and its protein localization in the testes. In a rat model, bacterial lippolysaccharide (LPS) induced atypical orchitis, and LPS treatment upregulated the expression of IMD and one of its receptor component proteins, i.e. receptor activity modifying protein 2 (RAMP2). IMD decreased both plasma and testicular levels of reactive oxygen species (ROS) production, attenuated the increase in the gene expression of the proinflammatory cytokines tumor necrosis factor alpha (TNFα), interleukin 6 (IL6) and interleukin 1 beta (IL1β), rescued spermatogenesis, and prevented the decrease in plasma testosterone levels caused by LPS. The restorative effect of IMD on steroidogenesis was also observed in hydrogen peroxide-treated rat primary Leydig cells culture. Our results indicate IMD plays an important protective role in spermatogenesis and steroidogenesis, suggesting therapeutic potential for IMD in pathological conditions such as orchitis.

Topics: Adrenomedullin; Animals; Body Weight; Cytokines; Gene Expression Regulation; Humans; Hydrogen Peroxide; Inflammation; Lipid Peroxidation; Lipopolysaccharides; Male; Mice; Orchitis; Oxidative Stress; Protein Transport; Rats; Receptors, Adrenomedullin; Testis; Testosterone

Adrenomedullin (AM), a member of the calcitonin gene-related peptide (CGRP) family, has been demonstrated to be a pronociceptive mediator. This study was undertaken to investigate the role of AM in acute inflammatory pain induced by formalin injection in rats. Interestingly Cerebrospinal fluid (CSF) levels of AM increased 45 min after formalin injection and a selective AM receptor antagonist, AM22-52, administered intrathecally (i.t.) decreased phase 2 flinching in a dose-dependent manner but not phase 1 flinching during the formalin test. This anti-hyperalgesic effect of i.t. AM22-52 lasted for 4 h or more. AM in the CSF contributes to the modulation of acute inflammatory pain in the formalin test, and blocking downstream signaling effects of the AM receptor has the potential to relieve pain associated with acute inflammation.

Topics: Adrenomedullin; Animals; Dose-Response Relationship, Drug; Humans; Inflammation; Injections, Spinal; Male; Pain; Pain Measurement; Peptide Fragments; Rats; Receptors, Adrenomedullin

Oxidative stress and inflammation are involved in the pathogenesis of acute lung injury (ALI). Adrenomedullin (AM) is an endogenous peptide with anti-inflammatory and antioxidant properties. This study investigated that whether AM treatment may ameliorate hyperoxia-induced ALI in rats via inhibition of oxidative stress and inflammation. Rats were randomized to receive continuous intravenous infusion of AM or saline through a microosmotic pump, and then ALI was induced by exposing the animals in sealed cages >95% oxygen for 72 h. Exposure to hyperoxia caused lung injury as increased infiltration of inflammatory cells and disruption of lung architecture. AM administration markedly improved these changes. Additionally, AM administration significantly increased glutathione peroxidase and superoxide dismutase activities. Meanwhile, hyperoxia-induced increase of lipid hydroperoxide level was markedly reduced by AM treatment. Moreover, nuclear factor-kappa B-DNA-binding activity, and production of the inflammatory mediators interleukin-6, keratinocyte-derived chemokine, and matrix metalloproteinase 9, were significantly inhibited by AM treatment. AM ameliorates hyperoxia-induced ALI in rats by suppression of oxidative stress and inflammation.

Topics: Acute Lung Injury; Adrenomedullin; Animals; Chemokines; Glutathione Peroxidase; Hyperoxia; Inflammation; Interleukin-6; Lipid Peroxides; Lung; Male; Matrix Metalloproteinase 9; NF-kappa B; Oxidative Stress; Rats; Rats, Sprague-Dawley; Superoxide Dismutase

Adrenomedullin(22-52) is a truncated peptide derived from adrenomedullin, a growth factor with antiapoptotic and immunoregulatory properties. It can act as an agonist or an antagonist depending on cell type. Its in vivo effects are unknown, but adrenomedullin(22-52) could possess immunomodulatory properties. This study was undertaken to evaluate the effect of adrenomedullin(22-52) in a mouse model of arthritis.. DBA/1 mice with collagen-induced arthritis (CIA) were treated with 1.2 μg/gm adrenomedullin(22-52) , adrenomedullin, or saline at arthritis onset. Bone mineral density was measured at the beginning of the experiment and when mice were killed. Mouse joints were processed for histologic analysis and protein studies, and spleens were examined for Treg cell expression. Cytokine expression was studied in mouse joint tissue and serum.. In mice with CIA, adrenomedullin and adrenomedullin(22-52) reduced clinical and histologic arthritis scores and shifted the pattern of articular and systemic cytokine expression from Th1 to Th2, as compared to untreated mice with CIA (controls). Tumor necrosis factor α, interleukin-6 (IL-6), and IL-17A levels were significantly decreased in the joints of mice with CIA treated with adrenomedullin or adrenomedullin(22-52) as compared to controls, whereas IL-4 and IL-10 levels were increased. Adrenomedullin(22-52) was more effective than adrenomedullin in modulating cytokine content and enhanced Treg cell function without changing Treg cell expression compared to controls. Adrenomedullin receptor binding and transcriptional adrenomedullin receptor expression were markedly increased in joints from controls, whereas adrenomedullin receptor binding was considerably decreased in treated animals. Mice with CIA treated with adrenomedullin or adrenomedullin(22-52) had considerably fewer apoptotic chondrocytes and diminished cartilage degradation. Adrenomedullin(22-52) completely prevented systemic bone loss by preserving osteoblastic activity, but without changes in osteoclastic activity.. Our findings indicate that adrenomedullin(22-52) , which has no vasoactive or tumor-inducing effects, is a potent antiinflammatory and bone-protective agent in this arthritis model.

Topics: Adrenomedullin; Animals; Apoptosis; Arthritis, Experimental; Bone Resorption; Chondrocytes; Cytokines; Inflammation; Joints; Male; Mice; Peptide Fragments; Receptors, Adrenomedullin; Severity of Illness Index

The anti-inflammatory peptide, adrenomedullin (AM), and its cognate receptor are expressed in lung tissue, but its pathophysiological significance in airway inflammation is unknown.. This study investigated whether allergen-induced airway inflammation involves an impaired local AM response.. Airway AM expression was measured in acute and chronically sensitized mice following allergen inhalation and in airway epithelial cells of asthmatic and nonasthmatic patients. The effects of AM on experimental allergen-induced airway inflammation and of AM on lung epithelial repair in vitro were investigated.. Adrenomedullin mRNA levels were significantly (P < 0.05) reduced in acute ovalbumin (OVA)-sensitized mice after OVA challenge, by over 60% at 24 h and for up to 6 days. Similarly, reduced AM expression was observed in two models of chronic allergen-induced inflammation, OVA- and house dust mite-sensitized mice. The reduced AM expression was restricted to airway epithelial and endothelial cells, while AM expression in alveolar macrophages was unaltered. Intranasal AM completely attenuated the OVA-induced airway hyperresponsiveness and mucosal plasma leakage but had no effect on inflammatory cells or cytokines. The effects of inhaled AM were reversed by pre-inhalation of the putative AM receptor antagonist, AM ((22-52)) . AM mRNA levels were significantly (P < 0.05) lower in human asthmatic airway epithelial samples than in nonasthmatic controls. In vitro, AM dose-dependently (10(-11) -10(-7) M) accelerated experimental wound healing in human and mouse lung epithelial cell monolayers and stimulated epithelial cell migration.. Adrenomedullin suppression in T(H) 2-related inflammation is of pathophysiological significance and represents loss of a factor that maintains tissue integrity during inflammation.

Topics: Administration, Intranasal; Adrenomedullin; Allergens; Animals; Asthma; Capillary Permeability; Cytokines; Disease Models, Animal; Endothelial Cells; Epithelial Cells; Gene Expression Regulation; Humans; Inflammation; Macrophages, Alveolar; Mice; Mice, Inbred BALB C

Adrenomedullin (AM) is a novel vasodilatatory peptide which acts primarily through the calcitonin receptor-like receptor (CLR) in combination with either receptor-activity-modifying-protein (RAMP) 2 or 3 (forming receptors, AM(1) and AM(2) respectively). AM plays an important role during inflammation, with its expression increasing following cytokine treatment, promoting macrophage action in situ and high expression by T cells during hypoxic conditions. Examination of T cell AM receptor expression has previously been incomplete, hence we here consider the presentation of AM receptors and their responsiveness to AM and glucocorticoids (GC). AM receptor expression was examined by PCR and flow cytometry in primary human T cells, revealing that RAMP2, 3 and CLR are physiologically expressed in unstimulated T cells, both intracellularly and on the cell surface. PHA stimulation decreased receptor proteins, significantly so for CLR and RAMP3. Incubation with AM elicited limited receptor alterations however, GC treatment (10(-6) M; 24 h) markedly affected cell surface expression, significantly increasing receptor components in unstimulated cells and significantly decreasing the same in stimulated T cells. Our findings indicate that human T cells utilize both AM(1) and AM(2) receptors, which are GC-sensitive in an activation-state dependent manner.

Topics: Adrenomedullin; Calcitonin Receptor-Like Protein; Calcium Signaling; Cyclic AMP; Dexamethasone; Gene Expression Regulation; Humans; Inflammation; Jurkat Cells; Lymphocyte Activation; Receptor Activity-Modifying Protein 2; Receptor Activity-Modifying Protein 3; Receptors, Adrenomedullin; T-Lymphocyte Subsets; T-Lymphocytes

It has been shown that pro-adrenomedullin is a good marker of the severity of septic shock but there are no data on the early changes in serum pro-adrenomedullin concentrations in patients with shock.. Twenty-one patients with septic shock and 21 healthy subjects studied as controls. Serum concentrations of pro-adrenomedullin, procalcitonin, ferritin, CRP and IL-6 were determined in all subjects at the initial observation. Patients with septic shock were also studied after 24 and 48 hours.. The concentrations of the acute phase proteins were significantly higher in patients with septic shock than in the control subjects during the entire study period (P<0.001). Only procalcitonin significantly decreased on the third day of observation with respect to both the first day (P=0.002) and the second day (P=0.006). Proadrenomedullin (P=0.017) and IL-6 (P=0.001) showed an AUC significantly different from the null hypothesis in differentiating the patients who survived and those who did not. The sensitivity and specificity of pro-adrenomedullin in the assessment of death were 71.4% and 72.7%, respectively, while IL-6 had a sensitivity of 92.9% and a specificity of 60.6%.. Proadrenomedullin is a reliable prognostic marker in patients with shock; further studies on a more consistent number of septic patients will definitively assess whether proadrenomedullin may replace the current prognostic markers in critically ill patients with shock due to sepsis.

Topics: Acute-Phase Proteins; Adrenomedullin; Adult; Aged; Aged, 80 and over; Area Under Curve; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Female; Ferritins; Humans; Inflammation; Interleukin-6; Male; Middle Aged; Prognosis; Protein Precursors; Sensitivity and Specificity; Shock, Septic; Time Factors

Endothelin-1 (ET-1) has been suggested to be involved in different types of pain due to its neuromodulatory nature. However, its role in inflammatory pain processing, specifically the origin-specific effect, has not yet been clearly defined. Therefore, the aim of this study is to determine the role of cell-type specific ET-1 induction in the modulation of inflammatory pain processing.. The current study assesses the effects of ET-1 over-expression specifically targeted to astrocytes (GET-1) or endothelial cells (TET-1) on the expression of pain-like behaviors induced by a model of inflammatory pain, consisting of a formalin injection into the hind paw.. The baseline sensitivity thresholds of GET-1 and TET-1 mice to the response elicited by tactile and radiant heat stimulation were similar to those observed in age-matched non-transgenic (NTg) controls. Relative to the NTg controls, GET-1 mice displayed a marked decrease in pain-like behavioral responses during the second phase of formalin-induced pain (i.e., 15-20 min after injection), whereas the responses elicited in TET-1 mice were unaltered. The levels of mRNA encoding adrenomedullin, calcitonin gene-related peptide and calcitonin-like receptor were elevated in the spinal cord of saline-injected GET-1 mice compared to those of NTg mice.. The current results support a suppressor role for astrocyte-derived ET-1 in inflammatory pain and suggest that the study of GET-1 mice might provide mechanistic insights for improving the treatment of inflammatory pain.

Topics: Adrenomedullin; Animals; Astrocytes; Behavior, Animal; Calcitonin Gene-Related Peptide; Calcitonin Receptor-Like Protein; Disease Models, Animal; Endothelial Cells; Endothelin-1; Formaldehyde; Gene Expression Regulation; Inflammation; Mice; Mice, Inbred C57BL; Mice, Transgenic; Pain; RNA, Messenger; Spinal Cord

In this study we investigate the effects of adrenomedullin on myocardial injury after ischemia-reperfusion (I/R) after abdominal aortic surgery.. Thirty-two Wistar rats were randomized into 4 groups (n = 8) as follows: control group (sham laparotomy), the aortic I/R group, aortic I/R plus adrenomedullin group (underwent aortic I/R periods, and received a bolus intravenous injection of .05 μg/kg/min adrenomedullin), and the control plus adrenomedullin group.. Biochemical analysis showed that aortic I/R significantly increased (P < .05) the plasma levels of troponin-I and tumor necrosis factor-α, and the myocardial tissue levels of malondialdehyde, superoxide dismutase, catalase, and angiotensin II, whereas aortic I/R plus adrenomedullin significantly decreased these same factors (P < .05). Aortic I/R significantly increased (P < .05) myocardial tissue levels of nitric oxide whereas aortic I/R plus adrenomedullin significantly increased the same factor (P < .05).. These results indicate that adrenomedullin has protective effects against myocardial injury induced by abdominal aortic I/R in rats.

Topics: Adrenomedullin; Angiotensin II; Animals; Aorta; Apoptosis; Biomarkers; Caspase 3; Catalase; Constriction; Endothelin-1; Immunohistochemistry; Inflammation; Lipid Peroxidation; Male; Malondialdehyde; Myocardial Reperfusion Injury; Myocytes, Cardiac; Nitric Oxide; Oxidative Stress; Random Allocation; Rats; Rats, Wistar; Superoxide Dismutase; Troponin I; Tumor Necrosis Factor-alpha

Long-term outcomes in patients surviving community-acquired pneumonia (CAP) are still incompletely understood. This study investigates the association of clinical parameters and blood markers with long-term mortality. We prospectively followed 877 CAP patients from a previous multicentre trial for 18 months follow-up and investigated all-cause mortality following hospital discharge. Overall mortality was 17.3% (95% CI 14.8-19.8%) with a 12.8% (95% CI 10.9-15.0%) mortality incidence rate per year. Initial risk assignment using the Pneumonia Severity Index was accurate during the 18 month follow-up. Multivariable regression models (hazard ratio, 95% CI) designated the following as independent risk factors for long-term mortality: male sex (1.7, 1.2-2.5); chronic obstructive pulmonary disease (1.5, 1.1-2.1); neoplastic disease (2.5, 1.7-3.7); and highest quartile of peak pro-adrenomedullin level (3.3, 1.7-6.2). Initial presentation with temperature>38.7°C (0.4, 0.2-0.6), chills (0.6, 0.4-0.99) and highest quartile of the inflammatory marker C-reactive-protein (0.3, 0.2-0.5) were independent protective factors. A weighted risk score based on these variables showed good discrimination (area under receiver operating characteristic curve 0.78, 95% CI 0.74-0.82). Pronounced clinical and laboratory signs of systemic inflammatory host response upon initial hospital stay were associated with favourable long-term prognosis. Further studies should address whether closer monitoring of high-risk CAP patients after hospital discharge favourably impacts long-term mortality.

Topics: Adrenomedullin; Aged; Aged, 80 and over; C-Reactive Protein; Chills; Community-Acquired Infections; Female; Fever; Humans; Inflammation; Male; Middle Aged; Neoplasms; Pneumonia; Prognosis; Prospective Studies; Protein Precursors; Pulmonary Disease, Chronic Obstructive; Risk; Severity of Illness Index; Sex Factors; Treatment Outcome

Adrenomedullin (AM) is a peptide involved in cardiovascular homeostasis. The aim of our study was to investigate whether circulating AM might be related to cardiac function, volume overload, oxidative stress and inflammation in hemodialysis patients. Plasma adrenomedullin, C-reactive protein (CRP), oxidized LDL (ox-LDL), lipoprotein (a), systolic and diastolic cardiac functions were assessed before hemodialysis in 80 patients as well as in 40 healthy control subjects. Plasma adrenomedullin levels were significantly higher in the hemodialysis group compared to the control group. Plasma adrenomedullin levels were negatively correlated with systolic and diastolic blood pressure, S/D ratio, deceleration time, left ventricular ejection fraction, ox-LDL and lipoprotein (a). However, it was positively correlated with CRP, delta body weight, mitral E/A wave, and inferior vena cava diameter. Higher plasma adrenomedullin levels may provide a possible index of cardiac dysfunction, systemic inflammation, and volume overload conditions in haemodialysis patients with concomitant cardiovascular disease. In addition, the negative correlation between ox-LDL, lipoprotein (a) and adrenomedullin may suggest that endogenous AM is an important protective factor in anti-atherosclerosis and might be useful as a new target for prevention and therapy for the disease.

Topics: Adrenomedullin; Adult; Blood Pressure; Blood Volume; C-Reactive Protein; Case-Control Studies; Coronary Artery Disease; Echocardiography, Doppler; Female; Humans; Inflammation; Lipoproteins, LDL; Male; Middle Aged; Oxidative Stress; Renal Dialysis

In intact mucosal tissues, epithelial cells are anatomically positioned in proximity to a number of subepithelial cell types, including endothelia. A number of recent studies have suggested that imbalances between energy supply and demand can result in "inflammatory hypoxia." Given these associations, we hypothesized that endothelial-derived, hypoxia-inducible mediators might influence epithelial function. Guided by cDNA microarray analysis of human microvascular endothelial cells (HMEC-1 line) subjected to hypoxia (pO(2) 20 torr, 8 h), we identified adrenomedullin (ADM) as a prominent hypoxia-inducible factor (HIF) that acts on epithelial cells through cell surface receptors. We assessed the functional ability for exogenous ADM to signal in human intestinal Caco2 cells in vitro by demonstrating a dose-dependent induction of Erk1/2phosphorylation. Further analysis revealed that ADM deneddylates cullin-2 (Cul2), whose action has been demonstrated to control the activity of HIF. Caco2 cells stably expressing a hypoxic response element (HRE)-driven luciferase promoter confirmed that ADM activates the HIF signaling pathway. Extensions of these studies revealed an increase in canonical HIF-1-dependent genes following stimulation with ADM. To define physiological relevance, we investigated the effect of ADM in a DSS model of murine colitis. Administration of ADM resulted in reduced inflammatory indices and less severe histological inflammation compared to vehicle controls. Analysis of tissue and serum cytokines showed a marked and significant inhibition of colitis-associated TNF-α, IL-1β, and KC. Analysis of circulating ADM demonstrated an increase in serum ADM in murine models of colitis. Taken together, these results identify ADM as an endogenously generated vascular mediator that functions as a mucosal protective factor through fine tuning of HIF activity.

Topics: Adrenomedullin; Animals; Caco-2 Cells; Cell Line; Colitis; Dextran Sulfate; Endothelial Cells; Epithelial Cells; Gene Expression Regulation; Humans; Hypoxia-Inducible Factor 1; Inflammation; Intestinal Mucosa; Mice; Mice, Inbred C57BL; Oxygen Consumption; Receptors, Adrenomedullin; Signal Transduction

Although adrenomedullin (AM) is known to ameliorate inflammatory processes, few data exist regarding the effect of AM on inflammatory colitis. Therefore, we examined the effect of AM on inflammatory response in vitro and in vivo colitis model.. In mice experimental colitis induced by 3% dextran sulfate sodium (DSS) in drinking water for 7 days, AM with 225-900 μg/kg in 0.5 ml of saline or saline alone were given intraperitoneally once a day. In the in vitro experiment, we determined the cytokine response in THP-1 cell activated by lipopolysaccharide with or without AM of 10 nM. Additionally, we performed wound healing assay in Caco-2 cell interfered by DSS with or without AM of 100 nM.. In the colitis model, AM significantly reduced the disease activity index, histological score, and local production of inflammatory cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 in accordance with reduction of serum amyloid A levels. Secretion of TNF-α in lipopolysaccharide-stimulated THP-1 cells was significantly reduced in the presence of AM. The distance of wound healing interfered by 0.25% DSS was significantly improved in the presence of AM of 100 nM.. These results demonstrate that AM could ameliorate DSS-induced experimental colitis possibly through suppression of systemic and local production of cytokines such as TNF-α, associated with acceleration of ulcer reepithelialization and colon tissue regeneration.

Topics: Adrenomedullin; Animals; Body Weight; Cell Line; Cell Movement; Colitis; Colon; Cytokines; Dextran Sulfate; Epithelium; Humans; Inflammation; Inflammation Mediators; Male; Mice; Mice, Inbred BALB C; Peroxidase; Serum Amyloid A Protein; Ulcer; Up-Regulation

Several new biomarkers are related to mortality in community-acquired pneumonia (CAP).. Aim of this study was to compare new biomarkers for the prediction of short- and long-term all-cause mortality in CAP.. We enrolled 728 patients (59.0 ± 18.2 yr) with CAP. Midregional proadrenomedullin (MR-proADM), midregional proatrial natriuretic peptide (MR-proANP), proarginin-vasopressin (copeptin), proendothelin-1 (CT-proET-1), procalcitonin (PCT), C-reactive protein, white blood cell (WBC) count, and clinical confusion, respiratory rate, blood pressure, and age over 65 years (CRB-65) score were determined on admission. Patients were followed up for 180 days.. In patients who died of any cause within 28 and 180 days (2.5 and 5.1%, respectively), MR-proADM, MR-proANP, copeptin, CT-proET-1 and PCT as well as CRB-65 were significantly higher compared with survivors. MR-proADM had the best performance for 28 days (HR 3.67) and 180 days (HR 2.84) survival. The C index of MR-proADM for 28-day survival (0.85) was superior to MR-proANP (0.81), copeptin (0.78), CT-proET-1 (0.79), and CRB-65 (0.72) for the prediction of mortality. For prediction of mortality at 180 days, the C index of MR-proADM (0.78) was higher than that for MR-proANP (0.74), copeptin (0.73), CT-proET-1 (0.76), PCT, C-reactive protein, and white blood cells. MR-proADM was independent of CRB-65, and added prognostic information for short- and long-term mortality. MR-proADM was an independent and strong predictor of short- and long-term mortality.. All new biomarkers were good predictors of short- and long-term all-cause mortality, superior to inflammatory markers, and at least comparable to CRB-65 score. MR-proADM showed the best performance. A combination of CRB-65 with MR-proADM might be the best predictor for mortality.

Topics: Adolescent; Adrenomedullin; Adult; Age Distribution; Aged; Aged, 80 and over; Atrial Natriuretic Factor; Biomarkers; Blood Pressure; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Cardiovascular Diseases; Community-Acquired Infections; Comorbidity; Endothelin-1; Female; Germany; Humans; Inflammation; Leukocyte Count; Male; Middle Aged; Pneumonia; Predictive Value of Tests; Protein Precursors; Respiratory Rate; Survival Analysis; Vasopressins; Young Adult

Borrelia burgdorferi stimulates a strong inflammatory response during infection of a mammalian host. To understand the mechanisms of immune regulation employed by the host to control this inflammatory response, we focused our studies on adrenomedullin, a peptide produced in response to bacterial stimuli that exhibits antimicrobial activity and regulates inflammatory responses by modulating the expression of inflammatory cytokines. Specifically, we investigated the effect of B. burgdorferi on the expression of adrenomedullin as well as the ability of adrenomedullin to dampen host inflammatory responses to the spirochete. The concentration of adrenomedullin in the synovial fluid of untreated Lyme arthritis patients was elevated compared with that in control osteoarthritis patient samples. In addition, coculture with B. burgdorferi significantly increased the expression of adrenomedullin in RAW264.7 macrophages through MyD88-, phosphatidylinositol 3-kinase (PI3-K)-, and p38-dependent signaling cascades. Furthermore, the addition of exogenous adrenomedullin to B. burgdorferi-stimulated RAW264.7 macrophages resulted in a significant decrease in the induction of proinflammatory cytokines. Taken together, these results suggest that B. burgdorferi increases the production of adrenomedullin, which in turn negatively regulates the B. burgdorferi-stimulated inflammatory response.

Topics: Adrenomedullin; Animals; Borrelia burgdorferi; Case-Control Studies; Cell Line; Chemokine CXCL2; Humans; Inflammation; Interleukin-1beta; Interleukin-6; Lyme Disease; Macrophages; Mice; Mice, Inbred C57BL; Osteoarthritis; Reverse Transcriptase Polymerase Chain Reaction; Synovial Fluid; Tumor Necrosis Factor-alpha

Adrenomedullin (ADM) and endothelin-1 (ET-1) are novel promising peptide biomarkers in chronic heart failure (CHF). According to recent studies among their pleiotropic effect they play roles in the regulation of inflammation. The aim of the study was to measure the above mentioned two vasoactive peptides in parallel in a well characterized population of patients with CHF, and study their associations with inflammatory markers.. A total of 186 patients (138 male, 48 female) with <45% left ventricular ejection fraction (LVEF), and without acute inflammatory disease, were enrolled. Plasma midregional-proADM (MR-proADM) and C-terminal-proET-1 (CT-proET-1) were determined by a novel sandwich immunoluminometric assay.. Increased MR-proADM and CT-proET-1 plasma levels were measured in patients with severe CHF (NYHA III-IV) as compared to the group of NYHA I-II (p<0.0001). MR-proADM and CT-proET-1 levels showed significant negative correlation with serum albumin and prealbumin levels (p

Topics: Adrenomedullin; Aged; Biomarkers; Chronic Disease; Cross-Sectional Studies; Endothelin-1; Female; Heart Failure; Humans; Inflammation; Male; Middle Aged; Ventricular Dysfunction, Left

Systemic inflammation arising from the organismal distribution of pathogen-associated molecular patterns is a major cause of clinical morbidity and mortality. Herein we report a critical and previously unrecognized in vivo role for germinal center kinase (GCK, genome nomenclature: map4k2), a mammalian Sterile 20 (STE20) orthologue, in PAMP signaling, and systemic inflammation. We find that disruption of gck in mice strongly impairs PAMP-stimulated macrophage cytokine and chemokine release and renders mice resistant to endotoxin-mediated lethality. Bone marrow transplantation studies show that hematopoietic cell GCK signaling is essential to systemic inflammation. Disruption of gck substantially reduces PAMP activation of macrophage Jun-N-terminal kinase (JNK) and p38 mitogen-activated protein kinases (MAPKs) via reduced activation of the MAPK-kinase-kinases (MAP3Ks) mixed lineage kinases (MLKs)-2 and -3. Extracellular signal-regulated kinase (ERK) and nuclear factor-kappaB (NF-kappaB) activation are largely unaffected. Thus, GCK is an essential PAMP effector coupling JNK and p38, but not ERK or NF-kappaB to systemic inflammation.

Topics: Adrenomedullin; Animals; Bone Marrow Transplantation; Cytokines; Extracellular Signal-Regulated MAP Kinases; Germinal Center Kinases; Hematopoietic Stem Cells; Inflammation; JNK Mitogen-Activated Protein Kinases; Macrophages; Mice; Mice, Knockout; NF-kappa B; p38 Mitogen-Activated Protein Kinases; Protein Serine-Threonine Kinases; Receptors, Pattern Recognition

Adrenomedullin (AM), a member of calcitonin gene-related peptide (CGRP) family, has been demonstrated to be a pronociceptive mediator [28]. This study was undertaken to investigate the role of AM in a model of complete Freund's adjuvant (CFA)-induced inflammatory pain. Injection of CFA, but not of saline, in the unilateral hindpaw produced an increase in the expression of AM-like immunoreactivity (AM-IR) in laminae I-II of the spinal cord as well as in small- and medium-sized dorsal root ganglion (DRG) neurons at 48 h. The content of AM in DRG on the side ipsilateral to CFA injection started to increase at 4 h and remained at high levels at 24 and 48 h. The selective antagonist of AM receptors, AM(22-52), administered intrathecally (i.t.) 24 h after CFA injection inhibited inflammation-associated hyperalgesia in a dose-dependent manner (2, 5 and 10 nmol). Impressively, this anti-hyperalgesic effect lasted for at least 24 h. I.t. administration of AM(22-52) (10 nmol) also reversed CFA-induced increase in AM-IR in the spinal dorsal horn and DRG. Furthermore, blockade of AM receptors abolished CFA-induced changes in the expression and content of CGRP-like immunoreactivity in these regions. Taken together, our results suggest that the upregulation of AM in DRG neurons contributes to the development of inflammatory pain, and this effect is mediated, at least in part, by enhancing the expression and release of CGRP. Blocking AM receptor downstream signaling effects using antagonists has the potential of relieving pain following the induction of inflammation.

Topics: Adrenomedullin; Animals; Calcitonin Gene-Related Peptide; Freund's Adjuvant; Ganglia, Spinal; Hyperalgesia; Immunoenzyme Techniques; Immunohistochemistry; Inflammation; Injections, Spinal; Male; Nociceptors; Peptide Fragments; Rats; Rats, Sprague-Dawley; Sensory Receptor Cells; Spinal Cord

Hyperactivation and hyperpermeability of the intestinal epithelium is a hallmark of IBD. AM has been shown to reduce the severity of colitis in the acetic acid and TNBS-induced colitis model, however the mechanism of the therapeutic effect of AM against the colitis has not been clarified. Here, we show that the protective capability of AM is associated with suppression of inflammation and maintenance of the intestinal epithelial barrier function. In the DSS-induced colitis model, intra-rectal AM-treated mice showed a reduction in loss of body weight and severity of colitis. AM-treatment suppressed phosphorylation of STAT1 and STAT3 in the colonic epithelium, and altered the cytokine balance in the intestinal T cells, with lower levels of IFN-gamma and TNF-alpha but higher levels of TGF-beta. Expression of the epithelial intercellular junctions such as tight and adherence junctions were sustained in the AM-treated mice. In contrast, the epithelial junctions were down-regulated in the control mice, leading to loss of epithelial barrier integrity and enhanced permeability. Collectively, these data indicate a broad spectrum of AM-induced effects with respect to protection against DSS-induced colitis, and suggest a potential therapeutic value of this treatment for IBD.

Topics: Administration, Rectal; Adrenomedullin; Animals; Cell Adhesion Molecules; Cytokines; Dextran Sulfate; Humans; Inflammation; Inflammatory Bowel Diseases; Intestinal Mucosa; Male; Mice; Mice, Inbred C57BL; STAT1 Transcription Factor; STAT3 Transcription Factor; T-Lymphocytes; Vasodilator Agents

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.

Topics: Adrenomedullin; Animals; Arthritis, Experimental; Autoimmunity; Collagen Type II; Down-Regulation; Immunologic Factors; Inflammation; Lymphocyte Activation; Mice; T-Lymphocyte Subsets; Th1 Cells

Although adrenomedullin is an indicator of cardiac dysfunction in haemodialysis patients, the clinical significance of midregional proadrenomedullin has not been elucidated. Objectives. We evaluated whether midregional proadrenomedullin reflects cardiac dysfunction, systemic inflammation or blood volume in haemodialysis patients.. Plasma midregional proadrenomedullin, C-reactive protein and delta body weight (indicating excessive blood volume), and two-dimensional as well as Doppler echocardiographic variables were measured just before haemodialysis in 70 patients with cardiovascular disease.. The median value of midregional proadrenomedullin was 1.93 nmol/l before haemodialysis, and these levels were significantly reduced following haemodialysis. Log [midregional proadrenomedullin] was positively correlated with left ventricular end-systolic volume index, diameter of inferior vena cava, C-reactive protein and delta body weight (r = 0.328, r = 0.421, r = 0.356, r = 0.364), and negatively with blood pressure, deceleration time of an early diastolic filling wave, pulmonary venous flow velocity ratio and left ventricular ejection fraction (r = -0.330, r = -0.324, r = -0.479, r = -0.373). Multivariate regression analysis revealed that pulmonary venous flow velocity ratio, diameter of inferior vena cava and C-reactive protein were independently related factors for midregional proadrenomedullin concentration.. Plasma midregional proadrenomedullin levels increase in association with cardiac dysfunction, systemic inflammatory status and systemic blood volume in haemodialysis patients with concomitant cardiovascular disease.

Topics: Adrenomedullin; Aged; Blood Volume; Body Weight; C-Reactive Protein; Echocardiography; Female; Heart Diseases; Humans; Inflammation; Kidney Diseases; Male; Middle Aged; Prospective Studies; Protein Precursors; Proteins; Renal Dialysis

Sepsis is a critical inflammatory condition from which numerous patients die due to multiple organ failure and septic shock. The vasoactive hormone adrenomedullin (AM) and its binding protein (AMBP-1) are beneficial in sepsis by abrogating the progression to irreversible shock and decreasing proinflammatory cytokine release. To investigate the anti-inflammatory mechanism, we studied to determine the effect of the AM/AMBP-1 complex on peroxisome proliferator-activated receptor-gamma (PPAR-gamma) expression and activation by using RAW264.7 cells and a rat endotoxemia model. LPS treatment significantly decreased PPAR-gamma expression in vivo and in vitro and was associated with increased TNF-alpha production. Treatment with AM/AMBP-1 for 4 h completely restored PPAR-gamma levels in both models, resulting in TNF-alpha suppression. In a knockdown model using small interfering RNA in RAW264.7 macrophages, AM/AMBP-1 failed to suppress TNF-alpha production in the absence of PPAR-gamma. LPS caused the suppression of intracellular cyclic AMP (cAMP), which was prevented by simultaneous AM/AMBP-1 treatment. Although incubation with dibutyryl cAMP significantly decreased LPS-induced TauNuF-alpha release, it did not alter PPAR-gamma expression. Through inhibition studies using genistein and PD98059 we found that the Pyk-2 tyrosine kinase-ERK1/2 pathway is in part responsible for the AM/AMBP-1-mediated induction of PPAR-gamma and the anti-inflammatory effect. We conclude that AM/AMBP-1 is protective in sepsis due to its vasoactive properties and direct anti-inflammatory effects mediated through both the cAMP-dependent pathway and Pyk-2-ERK1/2-dependent induction of PPAR-gamma.

Topics: Adrenomedullin; Animals; Cell Line; Complement Factor H; Cyclic AMP; Endotoxemia; Focal Adhesion Kinase 2; Inflammation; Lipopolysaccharides; Male; MAP Kinase Signaling System; Mice; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; PPAR gamma; Rats; Rats, Sprague-Dawley; Tumor Necrosis Factor-alpha; Up-Regulation

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.

Topics: Adrenomedullin; Amyloid; Animals; Anti-Inflammatory Agents; Anti-Inflammatory Agents, Non-Steroidal; Corticotropin-Releasing Hormone; Down-Regulation; Endotoxemia; Inflammation; Macrophages; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Nitric Oxide; Peptides; Peroxidase; Shock, Septic; Urocortins

Adrenomedullin (AM) belongs to the calcitonin gene-related peptide (CGRP) family and is a well known potent vasodilator. We show here that AM is a powerful pain-inducing neuropeptide. AM-like immunoreactivity is widely distributed in both CGRP-containing and lectin IB4-binding nociceptors in dorsal root ganglion and axon terminals in the superficial dorsal horn of the rat spinal cord. Specific binding sites for the radioligand, [(125)I]AM13-52 as well as immunoreactivity for receptor markers such as the calcitonin receptor-like receptor and three receptor-activity-modifying proteins are localized in the superficial dorsal horn, demonstrating the existence of AM/CGRP receptors in this region. Intrathecal injection of rat AM1-50, dose- and time-dependently, induced long-lasting heat hyperalgesia and increased the phosphorylation of Akt and GSK3beta in the dorsal horn. Pre- and posttreatments with the AM receptor antagonist AM22-52 and PI3 kinase inhibitors (LY294002 and Wortmannin) significantly blocked or reversed AM-induced heat hyperalgesia. Pre- and posttreatments with AM22-52 and Wortmannin also significantly blocked or reversed intraplantar capsaicin-induced heat hyperalgesia. Taken together, our results demonstrate that AM acts as a pain-inducing peptide in the dorsal horn. By activating specific receptors (likely AM2) and the PI3K/Akt/GSK3beta signaling pathway, AM could play a significant role in long-lasting heat hypersensitivity and inflammatory heat hyperalgesia.

Topics: Adrenomedullin; Animals; Behavior, Animal; Binding Sites; Calcitonin Gene-Related Peptide; Capsaicin; Enzyme Activation; Ganglia, Spinal; Inflammation; Injections, Spinal; Intracellular Signaling Peptides and Proteins; Male; Membrane Proteins; Nociceptors; Pain; Phosphotransferases; Rats; Rats, Sprague-Dawley; Receptor Activity-Modifying Proteins; Receptors, Adrenomedullin; Receptors, Peptide; Signal Transduction

Kawasaki disease (KD) is an acute inflammatory disorder of children frequently associated with the development of coronary artery abnormalities. Although a great deal is known about inflammatory and immune responses in acute KD, the mechanisms linking the immune response to vascular changes are not known. To gain further insight into this process, we performed a microarray gene expression analysis on RNA isolated from the peripheral blood mononuclear cells of four patients with KD during both their acute and convalescent phases. Forty-seven genes of 7129 genes examined showed an increased expression in three or all four patients in the acute compared with the convalescent phase of KD. Fourteen of these genes were significantly (p < 0.05) up-regulated, including several inflammatory response genes (e.g. S-100 A9 protein) and also anti-inflammatory genes (e.g. TSG-6). Of greatest interest, the adrenomedullin (ADM) gene, known to be associated with coronary artery vasodilation, was up-regulated in the acute phase of KD (p = 0.024). Up-regulation of ADM in the acute phase of KD was confirmed in peripheral blood mononuclear cells of 11 additional KD patients by reverse transcriptase-PCR (p < 0.01). Isolated blood monocytes but not lymphocytes were demonstrated by real-time PCR to have increased ADM mRNA (p = 0.01). Plasma ADM protein level in 32 additional KD patients was also confirmed to be higher in acute KD compared with convalescent KD (p < 0.032). It is interesting that from microarray results, other molecules known to be associated with coronary dilation, including nitric oxide, prostacyclin, acetylcholine, bradykinin, substance P, and serotonin, were not elevated in acute KD. Our current study suggests that ADM-expressing monocytes that infiltrate the coronary vascular wall may be the cause of coronary dilation in the acute phase of KD.

Topics: Acute Disease; Adrenomedullin; Child, Preschool; Echocardiography; Enzyme-Linked Immunosorbent Assay; Female; Humans; Immunoenzyme Techniques; Infant; Inflammation; Leukocytes, Mononuclear; Lymphocytes; Male; Monocytes; Mucocutaneous Lymph Node Syndrome; Oligonucleotide Array Sequence Analysis; Peptides; Reverse Transcriptase Polymerase Chain Reaction; RNA; Time Factors; Up-Regulation

Adrenomedullin (ADM) is a potent vasorelaxant peptide that plays important roles in cardiovascular homeostasis and inflammatory response. ADM derived from macrophages is one of the major sources of ADM that is produced in the inflammatory process. To assess the functions of ADM in inflammation, we studied the temporal changes in ADM production and its effect on secretion of macrophage migration inhibitory factor (MIF) and cytokine response of NR8383 rat macrophages activated by lipopolysaccharide (LPS). NR8383 cells were stimulated by LPS in the absence and presence of exogenous ADM, and the concentrations of ADM, MIF, and proinflammatory cytokines (IL-6, TNF-alpha, and IL-1beta) in the culture media and gene expressions of the cells were measured. We confirmed that the secretion and mRNA expression of ADM in the macrophages were markedly increased by LPS. ADM increased initial secretion of MIF and IL-1beta from both nonstimulated and LPS-stimulated cells, and it also increased basal and LPS-induced IL-6 secretion of the cells by 2- to 15-fold. However, it reduced secretion of TNF-alpha from LPS-stimulated cells by 34-56%. Our results suggest that ADM modulates MIF secretion and cytokine production and plays important roles in both the initiation and propagation of the inflammatory response.

Topics: Adrenomedullin; Animals; Anti-Inflammatory Agents; Cells, Cultured; Culture Media, Conditioned; Cytokines; DNA Primers; Dose-Response Relationship, Drug; Escherichia coli; Gene Expression Regulation; Inflammation; Inflammation Mediators; Interleukin-1; Interleukin-6; Lipopolysaccharides; Macrophage Migration-Inhibitory Factors; Macrophages; Peptides; Radioimmunoassay; Rats; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Time Factors; Tumor Necrosis Factor-alpha

Adrenomedullin (AM) administered intracolonically ameliorated the severity of acetic acid-induced colonic ulceration in rats. Ulcers were induced by subserosal injection of acetic acid into the colon. AM-treated group was administered 0.25-1.0 microg of AM in 0.5 ml of saline intracolonically once a day; the control group received only saline. AM administration dose-dependently and significantly reduced the size of the ulcerative lesions, the associated edema, and the infiltration of the affected area by inflammatory cells. AM also reduced tissue levels of interleukin-6, but not interferon-gamma. AM reduces the severity of acetic acid-induced colitis in rats, probably by inhibiting the production and/or release of Th-2 cell-derived factors such as interleukin-6.

Topics: Acetic Acid; Adrenomedullin; Animals; Anti-Inflammatory Agents, Non-Steroidal; Colitis; Indicators and Reagents; Inflammation; Interferon-gamma; Interleukin-6; Male; Peptides; Rats; Rats, Wistar; Th2 Cells

Many surface epithelial cells express adrenomedullin, a multifunctional peptide found in a wide number of body and cell systems. Recently, we and others have proposed that adrenomedullin has an important novel role in host defense. This peptide has many properties in common with other cationic antimicrobial peptides, including the human beta-defensins. Upon exposure of human gastric epithelial cells to viable cells of invasive or noninvasive strains of Helicobacter pylori, Escherichia coli, Salmonella enterica, or Streptococcus bovis, a significant increase in adrenomedullin secretion from these cells was demonstrated. Adrenomedullin gene expression was also increased in response to these microorganisms. Similar observations were noted when these cells were incubated with proinflammatory cytokines such as interleukin 1 alpha (IL-1 alpha), IL-6, tumor necrosis factor alpha and lipopolysaccharide. In cultured cells and an animal infection model, increased adrenomedullin peptide and gene expression was demonstrated when exposed to E. coli or Mycobacterium paratuberculosis, respectively. The data suggest there is a strong association between epithelial infection, inflammation, and adrenomedullin expression, which may have clinical relevance. The regulation of adrenomedullin expression may have therapeutic applications, such as improving or enhancing mucosal immunity.

Topics: Adenocarcinoma; Adrenomedullin; Epithelial Cells; Escherichia coli; Gastric Mucosa; Gene Expression Regulation; Helicobacter pylori; Humans; Infections; Inflammation; Interleukin-1; Interleukin-6; Lipopolysaccharides; Mycobacterium avium subsp. paratuberculosis; Peptides; Salmonella enterica; Stomach Neoplasms; Streptococcus bovis; Tumor Cells, Cultured; Tumor Necrosis Factor-alpha

Endothelial PAS domain protein 1 (EPAS1) has been identified as a member of the basic helix-loop-helix (bHLH)-PAS protein family, and plays a critical role in the regulation of hypoxia inducible genes. It remains unknown whether physiological stimuli other than hypoxia modulate EPAS1 expression. This study examined the inducible expression of EPAS1 by various cytokines and growth factors, and determined the target gene for EPAS1 in cardiac myocytes. In cultured cardiac myocytes, interleukin-1beta (IL-1beta) but not tumor necrosis factor alpha markedly increased the EPAS1 mRNA and protein levels in a time- and dose-dependent manner, whereas hypoxia increases the expression of EPAS1 protein but not its mRNA. Such an induction of EPAS1 by IL-1beta was efficiently inhibited by the pretreatment of the cells with Src kinase inhibitors, such as herbimycin A and PP1. The expression of adrenomedullin (AM) mRNA, which is also upregulated by IL-1beta, was dramatically increased in cardiac myocytes transduced with adenovirus expressing EPAS1. Transient transfection assays using the site-specific mutation of the AM promoter showed that EPAS1 overexpression increases the transcriptional activity through a sequence similar to the consensus HRE (hypoxia responsive element). These results suggest that IL-1beta induces the EPAS1 at the transcriptional level, which in turn activates the AM gene. Since IL-1beta has been implicated in the pathogenesis of heart failure and AM can ameliorate the cardiac function, our results suggest that EPAS1 plays a role in the adaptation of the cardiac myocytes during heart failure as well as in the regulation of gene expression by hypoxia.

Topics: Adrenomedullin; Animals; Basic Helix-Loop-Helix Transcription Factors; Gene Expression Regulation; Gene Transfer Techniques; Heart Failure; Inflammation; Interleukin-1; Myocytes, Cardiac; Peptides; Promoter Regions, Genetic; Rats; Rats, Wistar; RNA, Messenger; src-Family Kinases; Trans-Activators; Up-Regulation

In this study we investigated the effect of adrenomedullin (AM) on fMLP-mediated activation of human neutrophils. AM partially, but significantly, suppressed fMLP-induced upregulation of CD11b expression. The inhibitory effects of AM upon fMLP-induced upregulation of CD11b expression were completely blocked by CGRP [8-37], a CGRP receptor antagonist. AM significantly increased cAMP content in neutrophils and SQ-22,536, an adenylate cyclase inhibitor, and KT-5720, a PKA inhibitor, significantly blocked the inhibitory effects of AM upon fMLP-induced upregulation of CD11b expression. This study indicates that binding of AM to the CGRP receptor suppresses fMLP-induced upregulation of CD11b expression of human neutrophils by increasing intracellular cAMP levels. AM may play an important role in the regulation of inflammatory processes, especially in the binding of neutrophils to vascular endothelial cells and subsequent neutrophil emigration evident in acute pulmonary inflammation.

Topics: Adenine; Adenylyl Cyclase Inhibitors; Adrenomedullin; Calcitonin Gene-Related Peptide; Calcitonin Gene-Related Peptide Receptor Antagonists; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Drug Interactions; Enzyme Inhibitors; Humans; In Vitro Techniques; Inflammation; Macrophage-1 Antigen; N-Formylmethionine Leucyl-Phenylalanine; Neutrophils; Peptide Fragments; Peptides; Up-Regulation

The trophoblast invasion is a dynamic changes in cell-cell and cell matrix interaction and it create in the endometrio a reaction similar to the inflammatory reaction. In the recent past most of the investigator in this field had focus on the mediator of this process especially on cytokine and on vasoactive agent. We have studied the inducible isoform of nitric oxide synthase (iNOS), adrenomedullin (AM), fatty acid synthase (FAS), and S-100 protein. Several evidences had lead our choice: the two first factors are essentially local mediator of vasospasm which works in synergy during the inflammatory reaction, but the AM I addition stimulates the DNA synthesis and cell proliferation of Swiss 3T3 fibroblasts, induces the cell cycle progression from G0 to G1 phase and the malignant cell lines express AM mRNA and mRNA for its receptor and the pattern of distribution of ir-AM and its mRNA during murine development is similar to that of other growth factors (TGFb isoforms, PDGF, FGF, IGF 1 and 2); Fatty acid synthase (FAS) is a major biosynthetic enzyme of intracellular fatty acid synthesis, its expression and activity is enhanced in proliferative tissues, such as malignant cells; S-100 is an acid calcium binding protein present in central nervous system where it is in mainly concentrated in the glial cells, astrocytes, Schwann cells, and neurons. It regulates several functions such as cell-cell communication, cell growth, cell structure, energy metabolism, contraction, and intracellular signal transduction. Recently the appearance in blood of S100 in preterm infants has been used as a marker of brain damage in perinatal period. The iNOS, AM, S100 and FAS are localized in both decidual and trophoblastic cells in early pregnancy, but we found that changes in iNOS, S100, AM, and FAS are different in spontaneous abortion (SA) versus voluntary pregnancy termination (VPT). Considering the VPT as non pathologic pregnancy, this difference may reflect functional modifications of placental tissues. Our result shown that AM and NO are increased in VPT vs SA showing that when the process of implantation is on course we found an higher expression that we have during the inflammatory reaction. [Table: see text]

Topics: Abortion, Induced; Abortion, Spontaneous; Adrenomedullin; Animals; Cell Communication; Cell Cycle; Decidua; Embryo Implantation; Endometrium; Fatty Acid Synthases; Female; Growth Substances; Humans; Inflammation; Mice; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Peptides; Placenta; Pregnancy; RNA, Messenger; S100 Proteins; Trophoblasts; Tumor Cells, Cultured

Adrenomedullin (AM) has very recently been demonstrated to be produced and secreted from fibroblasts. The production of AM in the fibroblasts is augmented by inflammation-related substances, and Swiss 3T3 fibroblast cells express AM specific receptors coupled with adenylate cyclase. To assess the functions of AM secreted from fibroblasts, we measured the effect of AM on production in Swiss 3T3 cells of interleukin-6 (IL-6), a typical cytokine involved in the general inflammatory reactions. AM stimulated basal secretion of IL-6 5.5-fold, while other peptides elicited much weaker stimulatory effects. The effect of AM was inhibited with an AM receptor antagonist and a cAMP-dependent protein kinase (PKA) inhibitor. Furthermore, AM remarkably potentiated stimulatory effects of tumor necrosis factor-alpha, IL-1 beta and lipopolysaccharide on IL-6 production. This stimulatory effect of AM was induced through activation of gene transcription, which reached maximum within 30 min. These findings verify that AM is a rapid and extraordinarily potent regulator of IL-6 production in Swiss 3T3 cells acting through the cAMP-PKA pathway. The data thus obtained suggest that AM is a peptidergic regulator of inflammation.

Topics: 3T3 Cells; Adrenomedullin; Animals; Cyclic AMP-Dependent Protein Kinases; Drug Synergism; Enzyme Inhibitors; Gene Expression Regulation; Inflammation; Inflammation Mediators; Interleukin-1; Interleukin-6; Kinetics; Lipopolysaccharides; Membrane Proteins; Mice; Peptides; Receptors, Adrenomedullin; Receptors, Peptide; RNA, Messenger; Tumor Necrosis Factor-alpha; Vasodilator Agents