Poster Presentation Australasian Society for Immunology Annual Scientific Meeting 2014

Fibulin-1 plays a critical role in the pathogenesis of chronic obstructive pulmonary disease (COPD) (#185)

Gang Liu 1 , Andrew Jarnicki 1 , Prema Mono Nair 1 , Tatt Jhong Haw 1 , Michael Fricker 1 , Shaan Gellatly 1 , Richard Kim 1 , Mark Inman 2 , Gavin Tjin 3 , Jay Horvat 1 , Brian Oliver 3 , Darryl Knight 1 , Janette Burgess 3 , Phil Hansbro 1
  1. Centre for Asthma and Respiratory Diseases and Hunter Medical Research Institute, The University of Newcastle, Newcastle, New South Wales, Australia
  2. Division of Respirology, Department of Medicine, McMaster University, Hamilton, Ontario, Canada
  3. Woolcock Institute of Medical Research, Discipline of Pharmacology, The University of Sydney, Sydney, New South Wales, Australia

Airway remodelling is a critical feature of chronic obstructive pulmonary disease (COPD, aka emphysema). It narrows the airways and impairs lung function. Alteration of the extracellular matrix (ECM) proteins is a major characteristic of remodelling in COPD. Fibulin-1 is a glycoprotein that stabilises ECM and binds to fibronectin, periostin and tenacin-C. Two fibulin-1 variants (c and d) occur in mice and predominate in humans. The levels of fibulin-1, especially fibulin-1c, are increased in the lung tissue of COPD patients. However, the role of fibluin-1 in the COPD pathogenesis is unclear. We found that airway remodelling defined by increased collagen and a-smooth muscle actin (aSMA) around small airways and total collagen levels in lung tissue occurred after 8-weeks of cigarette smoke (CS)-exposure in our mouse model of experimental COPD. Moreover, fibulin-1 levels were increased around the small airways in lung tissue. CS-exposed fibulin-1c-deficient (-/-) mice were protected from airway remodelling, and had reduced collagen and aSMA around the airways compared to wild-type mice. They were also protected from emphysema and impaired lung function. Levels of periostin were increased and fibroenctin and tenascin-C were decreased in the lung. Surprisingly, CS-exposed fibulin-1c-/- mice also had less inflammatory cells and cytokines/chemokines (CXCL1, IL-33 and TNF-a) in the airways and lung. Our data suggest that fibulin-1c could regulate airway remodelling, emphysema and lung function changes through alterations in the deposition of ECM. Fibulin-1c also plays a key role in regulating inflammatory responses in experimental COPD. Thus, fibulin-1c may be a therapeutic target in COPD.