Purpose: Fibronectin (Fn) and tenascin-C (TnC) are two extracellular matrix proteins associated with remodeling changes. Fn and TnC gene and protein expression in lung tissue, including their predominant location in bronchial and pulmonary artery structures, have not yet been fully evaluated. The aim of the present study was to assess: (1) gene expression of Fn and TnC in lung samples from chronic obstructive pulmonary disease (COPD) and non-COPD subjects; and (2) protein content and location of Fn and TnC in both groups.
Methods: Consecutive subjects requiring lung resection due to lung cancer surgery were included. Lung specimens were examined for gene expression by quantitative real-time PCR (values expressed as fold change ratio). The analysis of their protein content and location was performed by western blot and immunohistochemical studies, respectively. Patients were divided into two cohorts according to COPD status.
Results: A total of 41 patients (20 with COPD and 21 without COPD) were included. An enhanced Fn gene expression was observed in the COPD group compared to the non-COPD group (4.73 ± 0.54 vs. 2.65 ± 0.57; P = 0.012), whereas no differences in gene TnC expression were observed (2.91 ± 0.44 vs. 2.60 ± 0.48; P = 0.633). No differences in lung protein content and location were found between groups. Immunohistochemical evaluation showed a predominantly vascular and bronchial location of Fn and TnC in both groups.
Conclusions: An enhanced lung gene expression of Fn was observed in COPD subjects compared to non-COPD subjects. No differences were found in Fn protein expression or in TnC gene or protein expression among groups.