Chronic lung diseases contribute significantly to the health burden world-wide. Primary human lung fibroblasts (phLFs) isolated from healthy and diseased tissue are frequently used to investigate fibroblast  behavior in chronic obstructive pulmonary disease (COPD) and interstitial lung disease (ILD).

Here, we investigate the disease-relevant functional differences in age- and sex-matched phLFs derived from healthy, COPD,  idiopathic pulmonary fibrosis (IPF) and non-IPF-ILD tissue. We identified functional differences in proliferation, fibroblast to myofibroblast transdifferentiation and ECM deposition, and correlated  these with clinical patient characteristics. To that end, we applied several immunofluorescence high-content imaging assays using phLFs. While both COPD and IPF phLFs showed a substantially enhanced deposition of disease-relevant Collagen I and V compared to healthy controls, non-IPF phLFs exhibited only  an increase in Collagen V deposition. ?SMA expression was increased in COPD- and non-IPF-ILD-derived phLFs in response to TGF?1, but not in non-IPF-ILD-derived phLFs.

Next, comparing the observed functional differences  with clinical parameters demonstrated that Collagen I and V deposition  were firmly  correlated with patients? age across disease origin, whereas Collagen V deposition was correlated only with donor smoking history.  In conclusion, our study identified pivotal diversities in disease-relevant fibroblast functions that should be considered for the design of future pathophysiological in vitro studies as well as drug discovery assays.