%0 Journal Article
%T Glycosaminoglycans Modify Elastase Action In Vitro and Enhance Elastase-Induced Cell Death in Cultured Fibroblasts
%A Jos¨¦ de Oliveira-Santos
%A Viviane Abreu Nunes
%A Ilana Cruz-Silva
%A Priscila Praxedes-Garcia
%A Andrezza Justino Gozzo
%A Mariana Rydlewski
%A Yamile Gonz¨¢lez Gonz¨¢lez
%A Helena Bonciani Nader
%A Mariana da Silva Ara¨²jo
%J ISRN Cell Biology
%D 2012
%R 10.5402/2012/973983
%X Human neutrophil elastase (HNE) has been shown to be involved on death of different cell types, including epithelial lung cells, which is related to several pulmonary diseases. Since HNE activity may be influenced by extracellular matrix (ECM) molecules such as glycosaminoglycans (GAGs), and fibroblasts are the most common ECM-producing cells of lung connective tissue, the aim of this work was to verify if HNE can induce fibroblast death and to study the enzyme modulation by GAGs. HNE-like activity was mimicked by using human neutrophils conditioned medium (NCM). Heparan sulfate and chondroitin 6-sulfate reduce the enzyme activity and modify its secondary structure. NCM reduced cell viability, and this effect was higher in the presence of those GAGs. NCM also increased DNA fragmentation, suggesting the occurrence of apoptosis, but without influence of GAGs. These results can contribute to the understanding of HNE modulation in physio- and pathological processes where this enzyme is involved. 1. Introduction Human neutrophil elastase (HNE) is a serine protease able to cleave fibrous elastin and other extracellular matrix (ECM) molecules, which plays essential structural function in lungs, arteries, skin, and ligaments [1, 2]. This enzyme is primarily located in the acidophilic granules of polymorphonuclear leucocytes, and its release is involved in tissue destruction and inflammation, despite the presence of potent endogenous inhibitors [3]. It has been implicated in several pulmonary diseases including emphysema, cystic fibrosis, acute lung injury (ALI), acute respiratory distress syndrome (ARDS), and chronic obstructive disease [3¨C6]. Corroborating these findings, HNE levels are increased in serum and bronchoalveolar lavage (BAL) fluid in clinical studies and animal models of ALI/ARDS [7]. HNE release has been associated to death of different cell types [8] such as lung epithelial and endothelial cells [2, 9]. The cell death promoted by HNE fits in the concept of ano£¿kis (from the Greek, homeless), which was defined as apoptosis resulting from the disruption of cell-matrix interactions, mainly induced by proteases, and whose integrity is essential for survival of adherent cells [10]. Besides the inhibitory mechanisms involved in the controlling of protease activity [11], some anionic polysaccharides named glycosaminoglycans (GAGs) can selectively affect that proteolytic activity [12¨C14]. Although GAGs have been shown to be able to modulate the activity and also modify the structure of different proteases [15, 16], there is relatively little information
%U http://www.hindawi.com/journals/isrn.cell.biology/2012/973983/