Componentes da matriz extracelular e seus reguladores no músculo liso brônquico na asma / Extracellular matrix components and regulators in the airway smooth muscle in asthma




There is an intimate relationship between the extracellular matrix (ECM) and smooth muscle cells within the airways. Few studies have comprehensively assessed the composition of different ECM components and its regulators within the airway smooth muscle (ASM) in asthma. With the aid of image analysis, the fractional area of total collagen and elastic fibres was quantified within the ASM of 35 subjects with Fatal Asthma (FA) and compared with 10 Nonfatal Asthma (NFA) patients and 22 nonasthmatic control cases. Expression of collagen I and III, fibronectin, versican, matrix metalloprotease (MMP)-1, 2, 9 and 12 and tissue inhibitor of metalloprotease-1 and 2 was quantified within the ASM in 22 FA and 10 control cases. In the large airways of FA cases, the fractional area of elastic fibres within the ASM was increased compared with NFA and controls. Similarly, fibronectin, MMP-9 and MMP-12 were increased within the ASM in large airways of FA cases compared with controls. Elastic fibres were increased in small airways in FA only in comparison with NFA cases. The results shower that, there is altered extracellular matrix composition and a degradative environment within the airway smooth muscle in fatal asthma patients, which may have important consequences for the mechanical and synthetic functions of airway smooth muscle.


smooth muscle asma metalloproteases inhibitor of protease músculo liso extracellular matrix metaloproteases matriz extracelular asthma inibidores de proteases

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