Antonio Lepedda

Publications (14) View all

• Article: Protein sulfhydryl group oxidation and mixed-disulfide modifications in stable and unstable human carotid plaques.

  Antonio Junior Lepedda, Angelo Zinellu, Gabriele Nieddu, Elisabetta Zinellu, Ciriaco Carru, Rita Spirito, Anna Guarino, Pierina De Muro, Marilena Formato
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  ABSTRACT: Objectives. Oxidative stress has been implicated in the outcome of atherosclerotic plaques. However, at present, no data are available neither on the degree of plaque protein sulfhydryl groups oxidation nor on its relationship with plaque vulnerability. We investigated the entity of protein-SH oxidative modifications, focusing on low molecular weight thiols adduction, in human carotid plaque extracts in relation to plaque stability/instability. Methods. Plaque stability/instability was histologically assessed. The extent of protein-SH oxidative modifications was established by a differential proteomic approach on fluorescein-5-maleimide-labeled plaque extracts and corresponding plasma samples from 48 endarterectomized patients. The analysis on protein thiolation was performed by capillary zone electrophoresis. Results. We observed a higher protein-SH oxidation of both plasma-derived and topically expressed proteins in unstable plaques, partly due to higher levels of S-thiolation. Conversely, in plasma, none of the investigated parameters discriminated among patients with stable and unstable plaques. Conclusions. Our results suggest the presence of a more pronounced oxidative environment in unstable plaques. Identifying specific oxidative modifications and understanding their effects on protein function could provide further insight into the relevance of oxidative stress in atherosclerosis.
  Oxidative Medicine and Cellular Longevity 01/2013; 2013:403973.
• Article: Kidney post-transplant monitoring of urinary glycosaminoglycans/proteoglycans and monokine induced by IFN-γ (MIG).

  Pierina De Muro, Rossana Faedda, Antonio Masala, Antonio Junior Lepedda, Elisabetta Zinellu, Milco Ciccarese, Maria Cossu, Pier Giorgio Pala, Rita Pasqualina Satta, Marilena Formato
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  ABSTRACT: Allograft rejection during the first year after renal transplantation can lead to persistent allograft dysfunction and reduced long-term graft survival. Thus, it is important to define early predictors of kidney damage, less invasive than allograft biopsy. Urinary glycosaminoglycan/proteoglycan concentration and distribution, N-acetyl-β-(D: )-glucosaminidase (NAG), and monokine induced by IFN-γ (MIG) levels were evaluated in the immediate post-transplant and during a 1-year follow-up. We observed increased urinary levels of MIG, urinary trypsin inhibitor and its degradation products, the lack of urinary heparan sulfate excretion, and the decreased chondroitin sulfate relative content at day 1 post-transplant in most patients who developed complications in the postoperative period. Moreover, urinary MIG levels showed significant correlations with NAG, C-reactive protein, and GFR at day 1 post-transplant. The monitoring of glycosaminoglycan/proteoglycan urinary pattern and the levels of urine MIG could serve as useful markers for predicting possible complications of transplantation, unraveling an early inflammatory state, on whose basis the immunosuppressive therapy could be appropriately modified.
  Clinical and Experimental Medicine 02/2012; · 1.58 Impact Factor
• Source

  Available from: Michel Spina

  Article: Fine structure of glycosaminoglycans from fresh and decellularized porcine cardiac valves and pericardium.

  Antonio Cigliano, Alessandro Gandaglia, Antonio Junior Lepedda, Elisabetta Zinellu, Filippo Naso, Alessandra Gastaldello, Paola Aguiari, Pierina De Muro, Gino Gerosa, Michele Spina, Marilena Formato
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  ABSTRACT: Cardiac valves are dynamic structures, exhibiting a highly specialized architecture consisting of cells and extracellular matrix with a relevant proteoglycan and glycosaminoglycan content, collagen and elastic fibers. Biological valve substitutes are obtained from xenogenic cardiac and pericardial tissues. To overcome the limits of such non viable substitutes, tissue engineering approaches emerged to create cell repopulated decellularized scaffolds. This study was performed to determine the glycosaminoglycans content, distribution, and disaccharides composition in porcine aortic and pulmonary valves and in pericardium before and after a detergent-based decellularization procedure. The fine structural characteristics of galactosaminoglycans chondroitin sulfate and dermatan sulfate were examined by FACE. Furthermore, the mechanical properties of decellularized pericardium and its propensity to be repopulated by in vitro seeded fibroblasts were investigated. Results show that galactosaminoglycans and hyaluronan are differently distributed between pericardium and valves and within heart valves themselves before and after decellularization. The distribution of glycosaminoglycans is also dependent from the vascular district and topographic localization. The decellularization protocol adopted resulted in a relevant but not selective depletion of galactosaminoglycans. As a whole, data suggest that both decellularized porcine heart valves and bovine pericardium represent promising materials bearing the potential for future development of tissue engineered heart valve scaffolds.
  Biochemistry research international. 01/2012; 2012:979351.
• Source

  Available from: Antonio Lepedda

  Article: Association between Human Plasma Chondroitin Sulfate Isomers and Carotid Atherosclerotic Plaques.

  Elisabetta Zinellu, Antonio Junior Lepedda, Antonio Cigliano, Salvatore Pisanu, Angelo Zinellu, Ciriaco Carru, Pietro Paolo Bacciu, Franco Piredda, Anna Guarino, Rita Spirito, Marilena Formato
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  ABSTRACT: Several studies have evidenced variations in plasma glycosaminoglycans content in physiological and pathological conditions. In normal human plasma GAGs are present mainly as undersulfated chondroitin sulfate (CS). The aim of the present study was to evaluate possible correlations between plasma CS level/structure and the presence/typology of carotid atherosclerotic lesion. Plasma CS was purified from 46 control subjects and 47 patients undergoing carotid endarterectomy showing either a soft or a hard plaque. The concentration and structural characteristics of plasma CS were assessed by capillary electrophoresis of constituent unsaturated fluorophore-labeled disaccharides. Results showed that the concentration of total CS isomers was increased by 21.4% (P < 0.01) in plasma of patients, due to a significant increase of undersulfated CS. Consequently, in patients the plasma CS charge density was significantly reduced with respect to that of controls. After sorting for plaque typology, we found that patients with soft plaques and those with hard ones differently contribute to the observed changes. In plasma from patients with soft plaques, the increase in CS content was not associated with modifications of its sulfation pattern. On the contrary, the presence of hard plaques was associated with CS sulfation pattern modifications in presence of quite normal total CS isomers levels. These results suggest that the plasma CS content and structure could be related to the presence and the typology of atherosclerotic plaque and could provide a useful diagnostic tool, as well as information on the molecular mechanisms responsible for plaque instability.
  Biochemistry research international. 01/2012; 2012:281284.
• Source

  Available from: Giampiero Capobianco

  Article: Plasma levels of C-reactive protein, leptin and glycosaminoglycans during spontaneous menstrual cycle: differences between ovulatory and anovulatory cycles.

  Giampiero Capobianco, Pierina de Muro, Gian Mario Cherchi, Marilena Formato, Antonio Junior Lepedda, Antonio Cigliano, Elisabetta Zinellu, Francesco Dessole, Laila Gordini, Salvatore Dessole
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  ABSTRACT: To assess the plasma levels of the inflammatory markers such as C-reactive protein (CRP), leptin, and glycosaminoglycans (GAGs) during the menstrual cycle. Eighteen healthy volunteers were divided into two groups according to the presence of ovulatory or anovulatory menstrual cycles. Blood samples were collected at different time points: at the menstrual phase (days 2-3), periovulatory phase (days 12-13), and luteal phase (days 23-24). CRP and leptin concentrations were measured by enzyme immunoassay. GAGs were isolated using ion-exchange chromatography on DEAE-Sephacel and quantified as hexuronate. The structural characterization of chondroitin sulfate (CS) isomers was performed by fluorophore-assisted carbohydrate electrophoresis (FACE). In the women with ovulatory cycles, plasma GAG levels differed significantly during menstrual cycle, with increased values at the periovulatory with respect to the menstrual phase. No significant differences in CRP and leptin concentrations were observed through the menstrual cycle in both the examined cycles, but inter-group analysis revealed significant differences of CRP and leptin levels between the ovulatory and anovulatory cycles with higher values at periovulatory phase in the ovulatory cycles. There are no fluctuations of both total GAG concentration and CS isomer content during menstrual cycle in the anovulatory cycles. A significant correlation between CRP and gonadotrophins was found. There is no significant difference in CRP across the menstrual cycle among ovulatory cycles, but there is a trend toward higher CRP at the periovulatory than the other phases, consistent with the significant difference in CRP between ovulatory and anovulatory cycles at the periovulatory phase. Both the trend and the significant result suggest an elevation in CRP with ovulation. These observations provide additional evidences to the hypothesis that the ovulation is an inflammatory-like phenomenon.
  Archives of Gynecology 03/2010; 282(2):207-13. · 0.91 Impact Factor