Recent studies suggested that interruption of the interaction of advanced glycation end products (AGEs), with the signal-transducing receptor receptor for AGE (RAGE), by administration of the soluble, extracellular ligand-binding domain of RAGE, reversed vascular hyperpermeability and suppressed accelerated atherosclerosis in diabetic rodents. Since the precise molecular target of soluble RAGE in those settings was not elucidated, we tested the hypothesis that predominant specific AGEs within the tissues in disorders such as diabetes and renal failure, N ⑀ -(carboxymethyl)lysine (CML) adducts, are ligands of RAGE. We demonstrate here that physiologically relevant CML modifications of proteins engage cellular RAGE, thereby activating key cell signaling pathways such as NF-B and modulating gene expression. Thus, CML-RAGE interaction triggers processes intimately linked to accelerated vascular and inflammatory complications that typify disorders in which inflammation is an established component.Receptor for AGE 1 (RAGE), a member of the immunoglobulin superfamily, was first described as a cell surface interaction site for advanced glycation end products (AGEs), products of glycation and oxidation of proteins and lipids (1-2). AGEs are a heterogeneous class of compounds, whose accumulation in disorders such as diabetes, renal failure, Alzheimer's disease, and, indeed, natural aging, albeit to a lesser degree, has suggested their potential contribution to the pathogenesis of complications that typify these conditions (3-7). Our previous studies demonstrated that both in vitro and in vivo derived heterogeneous AGEs ligate cell surface RAGE on endothelium (ECs), mononuclear phagocytes (MPs), vascular smooth muscle (VSMC), and neurons to activate cell signaling pathways such as ERK1/ERK2 kinases and NF-B (8 -9), thereby redirecting cellular function in a manner linked to expression of inflammatory and prothrombotic genes important in the pathogenesis of chronic disorders as apparently diverse as diabetic macrovascular disease and amyloidosis (10 -20).Our recent studies suggested that interruption of the interaction of AGEs with RAGE in vivo, by administration of soluble RAGE (sRAGE), the extracellular ligand-binding domain of RAGE, reversed vascular hyperpermeability and suppressed accelerated atherosclerotic lesion development and complexity in diabetic rodents (19 -20). In the latter studies, analysis of plasma demonstrated evidence of an sRAGE⅐AGE complex; immunoprecipitation of plasma obtained from diabetic sRAGEtreated mice with anti-RAGE IgG yielded species immunoreactive with both anti-RAGE IgG or affinity purified anti-AGE IgG, suggesting that sRAGE might bind up AGEs and limit their interaction with and activation of cell surface RAGE. The beneficial effects of sRAGE were independent of alterations in other risk factors, such as hyperglycemia and hyperlipidemia, implicating a role for AGE-RAGE interaction in the development of vascular dysfunction in diabetes (20).These past studies, however, did not elucidate ...
S100/calgranulin polypeptides are present at sites of inflammation, likely released by inflammatory cells targeted to such loci by a range of environmental cues. We report here that receptor for AGE (RAGE) is a central cell surface receptor for EN-RAGE (extracellular newly identified RAGE-binding protein) and related members of the S100/calgranulin superfamily. Interaction of EN-RAGEs with cellular RAGE on endothelium, mononuclear phagocytes, and lymphocytes triggers cellular activation, with generation of key proinflammatory mediators. Blockade of EN-RAGE/RAGE quenches delayed-type hypersensitivity and inflammatory colitis in murine models by arresting activation of central signaling pathways and expression of inflammatory gene mediators. These data highlight a novel paradigm in inflammation and identify roles for EN-RAGEs and RAGE in chronic cellular activation and tissue injury.
Background-The products of nonenzymatic glycation and oxidation of proteins, the advanced glycation end products (AGEs), form under diverse circumstances such as aging, diabetes, and kidney failure. Recent studies suggested that AGEs may form in inflamed foci, driven by oxidation or the myeloperoxidase pathway. A principal means by which AGEs alter cellular properties is through interaction with their signal-transduction receptor RAGE. We tested the hypothesis that interaction of AGEs with RAGE on endothelial cells enhances vascular activation.
Abstract.Advanced glycation end products (AGE) contribute to diabetic tissue injury by two major mechanisms,i.e., the alteration of extracellular matrix architecture through nonenzymatic glycation, with formation of protein crosslinks, and the modulation of cellular functions through interactions with specific cell surface receptors, the best characterized of which is the receptor for AGE (RAGE). Recent evidence suggests that the AGE-RAGE interaction may also be promoted by inflammatory processes and oxidative cellular injury. To characterize the distributions of AGE and RAGE in diabetic kidneys and to determine their specificity for diabetic nephropathy, an immunohistochemical analysis of renal biopsies from patients with diabetic nephropathy (n= 26), hypertensive nephrosclerosis (n= 7), idiopathic focal segmental glomerulosclerosis (n= 11), focal sclerosis secondary to obesity (n= 7), and lupus nephritis (n= 11) and from normal control subjects (n= 2) was performed, using affinity-purified antibodies raised to RAGE and two subclasses of AGE,i.e., Nϵ-(carboxymethyl)-lysine (CML) and pentosidine (PENT). AGE were detected equally in diffuse and nodular diabetic nephropathy. CML was the major AGE detected in diabetic mesangium (96%), glomerular basement membranes (GBM) (42%), tubular basement membranes (85%), and vessel walls (96%). In diabetic nephropathy, PENT was preferentially located in interstitial collagen (90%) and was less consistently observed in vessel walls (54%), mesangium (77%), GBM (4%), and tubular basement membranes (31%). RAGE was expressed on normal podocytes and was upregulated in diabetic nephropathy. The restriction of RAGE mRNA expression to glomeruli was confirmed by reverse transcription-PCR analysis of microdissected renal tissue compartments. The extent of mesangial and GBM immunoreactivity for CML, but not PENT, was correlated with the severity of diabetic glomerulosclerosis, as assessed pathologically. CML and PENT were also identified in areas of glomerulosclerosis and arteriosclerosis in idiopathic and secondary focal segmental glomerulosclerosis, hypertensive nephrosclerosis, and lupus nephritis. In active lupus nephritis, CML and PENT were detected in the proliferative glomerular tufts and crescents. In conclusion, CML is a major AGE in renal basement membranes in diabetic nephropathy, and its accumulation involves upregulation of RAGE on podocytes. AGE are also accumulated in acute inflammatory glomerulonephritis secondary to systemic lupus erythematosus, possibly via enzymatic oxidation of glomerular matrix proteins.
In neonates, preterm infants, and infants aged 1 through 11 months, pantoprazole (high dose) improved pH-metry parameters after ≥5 consecutive daily doses, and was generally well tolerated for ≤6 weeks.
This study investigates the impact of severe renal impairment on the pharmacokinetics of cabotegravir, an investigational HIV‐1 integrase inhibitor. This was a phase I, open‐label, parallel‐group, multicenter study conducted in 8 participants with severe renal impairment (creatinine clearance <30 mL/min; no renal replacement therapy) and 8 healthy participants (creatinine clearance >90 mL/min; 2 women/group; 6 men/group) matched for sex, age (±10 years), and body mass index (±25%). Participants received a single 30‐mg oral cabotegravir tablet to determine total and unbound plasma cabotegravir concentrations. Arithmetic and geometric least squares means were calculated, and cabotegravir noncompartmental pharmacokinetic parameters were compared using geometric least squares mean ratios with 90% confidence intervals. Safety was assessed throughout the study. Geometric least squares mean ratios (90% confidence intervals) were 0.97 (0.84–1.14) for area under the plasma concentration‐time curve extrapolated to infinity, 1.01 (0.87–1.17) for maximum observed plasma concentration, 1.31 (0.84–2.03) for unbound cabotegravir 2 hours after dosing, and 1.51 (1.19–1.92) for unbound cabotegravir 24 hours after dosing. All adverse events were grade 1, except grade 3 lipase elevation in a participant with renal impairment. Severe renal impairment did not impact plasma cabotegravir exposure, and cabotegravir may be administered without dose adjustment in renal impairment among patients not receiving renal replacement.
This single-dose study evaluated the bioequivalence, food effect, and safety of 2 experimental, 2-drug, fixed-dose formulations of 50 mg dolutegravir and 300 mg lamivudine (formulation AH and formulation AK) as compared with coadministration of single-entity tablets of 50 mg dolutegravir and 300 mg lamivudine (reference). In fasted subjects, formulation AH lamivudine exposure was similar to the reference; however, dolutegravir exposure was consistently higher in formulation AH, with area under the concentration-time curve (AUC) and maximum concentration (C max ) approximately 27% to 28% greater than reference. Formulation AK met bioequivalence standards to the reference for dolutegravir (AUC 0-Ý and C max ) and lamivudine (AUC 0-Ý and AUC 0-t ) exposure; however, dolutegravir AUC 0-t and lamivudine C max were approximately 16% and 32% higher than the reference, respectively. A high-fat meal increased dolutegravir AUC and C max by up to 33% and 21%, respectively, and decreased lamivudine C max by approximately 30%. Both test and reference formulations were well tolerated. The results support further development of formulation AK as a novel, 2-drug, fixed-dose combination tablet treatment for patients with HIV.
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