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Michele Andreucci,
Giorgio Fuiano,
Pierangela Presta,
Pasquale Esposito,
Teresa Faga, Vincenzo Bisesti,
Alfredo Procino,
Vincenzo Altieri,
Carmela Tozzo,
Bruno Memoli,
Ashour Michael
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ABSTRACT: Radiocontrast medium induced nephrotoxicity is a major clinical problem. There is considerable interest in reducing the incidence of acute renal failure due to the use of radiocontrast media (RCM). Reduction of renal blood flow and direct toxic effect on renal tubular epithelial cells have been postulated as major causes of RCM nephropathy. Understanding the molecular mechanisms by which RCM cause cell damage may allow the development of pharmacological therapy to prevent their nephrotoxicity. In this work we have investigated the signaling pathways that may be affected by RCM. The incubation of human renal tubular proximal cells with sodium diatrizoate, iopromide and iomeprol caused a marked dephosphorylation of the kinase Akt on Ser473 within 5min of incubation. RCM also caused a decrease in cell viability, which was substantially alleviated by transfecting the cells with a constitutively active form of Akt. Further downstream targets of Akt, including the Forkhead family of transcription factors FKHR and FKHRL1, were also dephosphorylated by RCM at Thr24 and Thr32, respectively. The P70S6 kinase was also dephosphorylated at Thr389 and Ser371 by RCM. However there was a more dramatic decrease in phosphorylation of the phosphorylated form of mammalian target of rapamycin (mTOR) and of the extracellular-signal regulated kinases (ERK) 1/2 caused by sodium diatrizoate than by iopromide. These results demonstrate the effect of RCM on some intracellular signaling pathways that may allow understanding of the mechanism of their toxicity and may allow the development of strategies to overcome their adverse effects.
Biochemical Pharmacology 11/2006; · 4.70 Impact Factor
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Roberto Berni Canani,
Laura Tanturri de Horatio,
Gianluca Terrin,
Maria Teresa Romano,
Erasmo Miele,
Annamaria Staiano,
Luciano Rapacciuolo,
Gaetano Polito, Vincenzo Bisesti,
Francesco Manguso,
Gianfranco Vallone,
Antonio Sodano,
Riccardo Troncone
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ABSTRACT: To assess the effectiveness of the combined use of fecal calprotectin (FC), anti-Saccharomyces cerevisiae antibody (ASCA), perinuclear staining antineutrophil antibody (pANCA), small intestinal permeability test (IP), and bowel wall ultrasonography measurement (BWUS) in the diagnostic work-up of children with suspected inflammatory bowel disease (IBD).
All children referred for initial assessment of possible IBD were eligible. Patients with symptoms or signs (right-lower quadrant mass, perianal disease, or hematochezia) mandating a complete work-up for IBD were excluded. All enrolled patients underwent a clinical, laboratory, radiographic, and endoscopic evaluation including biopsy examinations. The immunoglobulin (Ig)G and IgA ASCA, IgG pANCA, FC, IP, and BWUS were tested in all patients at the initial assessment.
A final diagnosis of IBD was made in 27 patients: 17 Crohn disease and 10 ulcerative colitis. Eighteen children had other gastrointestinal diagnoses (8 functional bowel disorders, 5 food allergy-mediated diseases, 4 infectious enterocolitis, 1 familial Mediterranean fever). In patients with simultaneous abnormal values of FC, BWUS, and ASCA/pANCA, the estimated probability of having IBD was 99.47%. Patients with negative results on all tests had a 0.69% of probability of IBD.
The incorporation of noninvasive diagnostic tests into the initial diagnostic approach may avoid unnecessary invasive procedures and facilitate clinical decision-making when the diagnosis of IBD in children is initially uncertain.
Journal of Pediatric Gastroenterology and Nutrition 02/2006; 42(1):9-15. · 2.30 Impact Factor
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Bruno Memoli,
Giuseppe Grandaliano,
Michela Soccio,
Loredana Postiglione,
Brunella Guida, Vincenzo Bisesti,
Pasquale Esposito,
Alfredo Procino,
Daniela Marrone,
Ashour Michael,
Michele Andreucci,
Francesco Paolo Schena,
Giovanni Pertosa
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ABSTRACT: Soluble gp130 (sgp130) is a soluble circulating receptor of IL-6 with "antagonistic" biologic activity. It is generated indepen-dently by either shedding of the extracellular domain of membrane gp130 or alternative mRNA splicing. This study was addressed to clarify the mechanisms underlying sgp130 synthesis and release in patients who undergo regular dialysis treatment (RDT) using dialytic membranes with different biocompatibility. Two groups of RDT patients were enrolled: 11 patients who were treated with cellulosic membranes (C) and 10 patients who were treated with synthetic membranes (S). Ten healthy subjects constituted the control group. Serum samples and peripheral blood mononuclear cells (PBMC) were harvested in all groups (before dialysis in RDT patients). PBMC were cultured for 24 h in the absence or presence of LPS. The serum levels of sgp130 were significantly higher in C group than in control and S patients (C, 603.1 89.9; control, 396 49.5; S, 423.4 27.7 ng/ml; P < 0.01). PBMC from C patients, in the absence of any mitogenic stimulation, released a significantly greater amount of sgp130 as compared with S and control groups (C, 532.6 161.2; S, 332.4 148.6; control, 341.4 125.4 pg/ml; P < 0.01). The sgp130 release was positively correlated with the release of both IL-6 (r 0.336, P < 0.05) and sIL-6R receptor (r 0.324, P < 0.05). A significantly higher gp130 gene expression was also observed in unstimulated PBMC from C patients when compared with control and S groups. It is interesting that the expression of the 85-bp exon characteristic of the alternative splicing mRNA for sgp130 was low in all groups. Finally, confocal microscopy analysis showed an increased expression of gp130 on cell surface in unstimulated PBMC from C patients as compared with control and S groups. Our results demonstrate that in patients on RDT with C membranes, the synthesis and release of sgp130 "antagonistic" receptor is significantly increased. This release is seemingly due to a shedding of membrane-bound gp130 receptor. The increased sgp130 release may partially counteract the inflammatory effects caused by IL-6. J Am Soc Nephrol 16: 1099-1107, 2005. doi: 10.1681/ASN.2004080628 T here is an increasing body of evidence that IL-6 plays a prominent role in the course of several diseases (1); available data, indeed, suggest that IL-6 and its soluble receptor (sIL-6R) operate as central regulators of inflammatory processes (2,3). Elevated levels of IL-6 in patients with ESRD are associated with many negative issues, such as malnutrition, immunodeficiency, and cardiovascular events, and may predict the poor outcome of these patients (4 –9). According to Sten-vinkel et al. (10), IL-6 may play a central role in the genesis of inflammatory-driven malnutrition and may be regarded as a major atherogenic cytokine. IL-6 effects on target cells occur via a complex receptor system, composed of a ligand binding subunit (IL-6R or gp80) and a signal-transducing glycoprotein (gp130), both expressed on the cell surface (11). After binding of IL-6 to IL-6R, the IL-6/IL-6R complex triggers the dimerization of the signal-transducing receptor component gp130 (11). This receptor– ligand interaction activates Janus kinases that phosphorylate the tyrosine residues of the cytoplasmic portion of gp130, acti-vating a variety of members of signal transducers and activa-tors of transcription family (12,13). Soluble forms of both IL-6R and gp130 represent the circu-lating receptors of IL-6. These two soluble receptors are func-tionally different; sIL-6R, in fact, when complexed with circu-lating IL-6, may still induce dimerization of the membrane surface gp130 on cells that lack IL-6R and, therefore, represents, unlike other soluble cytokine receptors, a potent "agonistic" molecule (14,15). Soluble gp130 (sgp130), on the contrary, is a monomeric 100-kD glycoprotein that can efficiently bind the circulating binary IL-6/sIL-6R complex with "antagonistic" ef-fects (16). Elevated plasma levels of sgp130 have been recently reported in patients with ESRD (17), but no clear modulation by different dialysis membranes was demonstrated (17). Both sIL-6R and sgp130 are generated independently by either one of these two mechanisms: Shedding of the extracel-lular domain because of proteolytic cleavage and alternative
Journal of the American Society of Nephrology 04/2005; · 9.66 Impact Factor
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ABSTRACT: Proinflammatory cytokines, in addition to their role in host defence, may be considered mediators of disease; a reduction of cytokine synthesis or effects is, therefore, becoming a target of many diseases. IL-6 is a pro-inflammatory cytokine that may play a role in several clinical problems related to dialysis treatment. An enhanced spontaneous production of IL-6 by Peripheral Blood Mononuclear Cells (PBMC) harvested from ESRD patients dialyzed with a poor biocompatible membrane has been first demonstrated by our group. These results were also obtained in patients undergoing continuous peritoneal dialysis, in absence of peritonitis. We have also demonstrated that IL-6 release was inversely correlated with serum albumin changes. Biological activities of IL-6 may be modulated by two soluble circulating receptors, namely sIL-6R and sgp130. sIL-6R may enhance the inflammatory effects of IL-6 and is, therefore, an "agonistically" acting molecule. We have recently studied sIL-6R production in ESRD patients dialyzed with different membranes; the conclusion was that poor biocompatible membranes, via the sIL-6R, might further increase the inflammatory effects of IL-6. On the contrary, sgp130 can efficiently bind the IL-6/sIL-6R complex with "antagonistic" effects. We have evaluated plasma levels of sgp130 in 18 ESRD patients regularly dialyzed with hemophan membranes (HE) and in 15 patients dialyzed with more biocompatible synthetic membranes (BIO). Our results demonstrate that plasma levels of sgp130 in HE are 33% higher than in both healthy controls and BIO. Circulating levels of sgp130 were correlated positively with C-reactive protein (r: 0.338, p<0.05) and negatively with serum albumin (r: -0.334, p<0.05). These results suggest that higher circulating levels of sgp130 are likely associated with higher IL-6 levels. These higher amounts are probably insufficient to control the activity of IL-6 and may be considered only as a marker of PBMC activation.
Seminars in Nephrology 10/2004; 24(5):492-4. · 2.12 Impact Factor
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Contributions to nephrology 02/2003; · 1.49 Impact Factor
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Bruno Memoli,
Roberto Minutolo, Vincenzo Bisesti,
Loredana Postiglione,
Angela Conti,
Luigi Marzano,
Alfredo Capuano,
Michele Andreucci,
Mario M Balletta,
Bruna Guida,
Ciro Tetta
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ABSTRACT: Protein malnutrition, a condition associated with an albumin concentration less than 3.5 g/dL, has been shown to be a major risk factor for increased mortality in hemodialysis patients. The aim of this cross-over study was to evaluate the relationship between the type of membrane adopted and serum albumin changes by measuring peripheral blood mononuclear cells (PBMC) interleukin-6 (IL-6) release, serum albumin, and plasma concentrations of C-reactive protein (CRP) in 18 patients dialyzed with different membranes. During the study, all patients were dialyzed with cuprophan (CU), synthetically modified cellulosic (SMC) membrane (a new cellulosic membrane with lesser complement activation), and cellulose diacetate (CD) membrane, and have served as their own controls. IL-6 spontaneous release by PBMC resulted after 3 months of SMC (436.2 +/- 47.4 pg/mL) significantly (P < 0.05) reduced as compared with CU (569.3 +/- 24.5 pg/mL). This effect was more evident after 6 months of dialysis with SMC (220 +/- 35.3 pg/mL, P < 0.01 versus CU and versus 3 months of SMC). The passage to CD membrane was followed by a progressive new increase in the IL-6 PBMC release (332.3 +/- 30.7 after 3 months, and 351.2 +/- 35.8 pg/mL after 6 months, respectively) that, however, remained significantly (P < 0.05) lower than CU. The behavior of CRP plasma levels resembled that of IL-6 PBMC release (23.3 +/- 4.7 in CU, 11.0 +/- 2.1 after 3 months in SMC, and 7.9 +/- 1.5 after 6 months in SMC, respectively). IL-6 release values were positively correlated with circulating levels of CRP (r = 0.3264, P < 0.002). Serum albumin increased after 6 months of dialysis with SMC membranes (3.25 +/- 0.09 g/dL in CU and 3.64 +/- 0.07 g/dL in SMC, P < 0.05). When the patients were switched to CD, serum albumin showed a slight, though not statistically significant, decrease. Serum albumin concentrations negatively correlated with both IL-6 release values (r = -0.247, P < 0.05) and CRP plasma levels (r = -0.433, P < 0.001). In conclusion, our data clearly show that a significant relationship exists between biocompatibility of the membranes and serum albumin changes; serum albumin levels, in fact, are negatively correlated with the PBMC spontaneous IL-6 release values and CRP circulating levels.
American Journal of Kidney Diseases 03/2002; 39(2):266-73. · 5.43 Impact Factor
