TY - JOUR T1 - Decreased Expression of EC-SOD and Fibulin-5 in Alveolar Walls of Lungs From COPD Patients JO - Archivos de Bronconeumología T2 - AU - García-Valero,José AU - Olloquequi,Jordi AU - Rodríguez,Esther AU - Martín-Satué,Mireia AU - Texidó,Laura AU - Ferrer,Jaume SN - 03002896 M3 - 10.1016/j.arbres.2020.12.032 DO - 10.1016/j.arbres.2020.12.032 UR - https://archbronconeumol.org/en-decreased-expression-ec-sod-fibulin-5-in-articulo-S0300289621000168 AB - IntroductionThe aim of this study is to analyze the expression of the main oxidant scavenger superoxide dismutase (EC-SOD), its main binding protein Fibulin-5 and several oxidative and nitrosative-derived products in the lung of COPD patients and controls. Materials and methodsLung tissue samples from 19 COPD patients and 20 control subjects were analyzed. The architecture of elastic fibres was assessed by light and electron microscope histochemical techniques, and levels of EC-SOD and fibulin-5 were analyzed by immunohistochemistry and RT-PCR. The impact of oxidative stress on the extracellular matrix was estimated by immunolocalization of 4-hydroxynonenal (4-HNE), malondialdehyde (MDA) and 3-nitrotyrosine (3-NYT) adducts. ResultsAlveolar walls of COPD patients exhibited abnormal accumulations of collapsing elastic fibres, showing a pierced pattern in the amorphous component. The semiquantitative analysis revealed that COPD patients have a significantly reduced expression of both EC-SOD and fibulin-5 (0.59±0.64 and 0.62±0.61, respectively) in alveolar, bronchiolar and arteriolar walls compared to control subjects (1.39±0.63 and 1.55±0.52, respectively, p<0.05). No significant changes in mRNA levels of these proteins were observed between groups. Among the oxidation markers, malondialdehyde was the best in distinguishing COPD patients. ConclusionsCOPD patients show a reduced expression of EC-SOD and fibulin-5 in the lung interstitium. Paralleling the reduction of EC-SOD levels, the decrease of fibulin-5 expression in COPD lungs supports the hypothesis of an impaired pulmonary antioxidant response in COPD patients. ER -