Fibroblast contractility - Usual interstitial pneumonia and nonspecific interstitial pneumonia

The aim of this study was to compare the function of lung fibroblasts obtai ned from surgically biopsied specimens of patients with idiopathic pulmonar y fibrosis/usual interstitial pneumonia (UIP; n = 5), nonspecific interstit ial pneumonia (NSIP; n = 5), and normal parts of surgically resected lungs (control; n = 5). The results showed that (1) fibroblasts obtained from UIP showed increased contractility compared with those obtained from NSIP or c ontrols (UIP, 72.7 +/- 6.21%; NSIP, 32.8 +/- 5.46; controls, 28.5 +/- 3.51, p < 0.01 in UIP versus NSIP or control); (2) this increase in contractilit y was consistent with enhanced F-actin content in fibroblasts; (3) conditio ned media from UIP fibroblast cultures enhanced control fibroblast contract ility, whereas those obtained from NSIP or controls did not; (4) the 180 an d 25 kD products representing the contractility in conditioned media were i dentified as fibronectin (ED-A domain) and TGF-<beta>1 by immunoblots, resp ectively; (5) the UIP-conditioned media contained higher amounts of fibrone ctin or TGF-beta1 (fibronectin: UIP 289 +/- 47.1 ng/ml, NSIP 121 +/- 23.0, control 118 +/- 16.0; TGF-beta1: UIP 798 +/- 119 pg/ml, NSIP 246 +/- 69.1, control 247 +/- 53.6, p < 0.01 in UIP versus NSIP or control); (6) the cont radility positively correlated with the amount of either fibronectin (r = 0 .867, p < 0.001, n = 15) or TGF-beta1 (r = 0.939, p < 0.001, n = 15), respe ctively. Thus, UIP fibroblasts showed greater contractility than did NSIP f ibroblasts and upregulated control fibroblasts.