Hardie Lab
Projects

Current Projects

These projects are designed to provide preclinical data to identify novel approaches for treating progressive fibrosis. Many of these projects utilize pharmacologic agents that are currently in advanced clinical trials for a number of diseases. Therefore, important findings could be relatively rapidly translated into clinical trials in patients with fibrotic disease.

Identification of specific cell signaling pathways which can be targeted alone or in combination to reverse progressive pulmonary fibrosis

This project focuses on identifying cell signaling pathways which are downstream of epidermal growth factor receptor activation which mediate fibroproliferation. The goal is to identify specific pathways which can be pharmacologically targeted that not only prevent lung fibrosis progression, but augment reversal of existing fibrosis.

Funding:

National Institutes of Health/National Heart, Lung, and Blood Institute including RO1 and P50 grants.

Collaborators:

George Thomas, PhD
University of Cincinnati
Department of Cancer and Cell Biology

Identification of the sources of fibroblasts and mesenchymal cells which comprise and produce pathologic lung fibrosis

The goal of this project is to determine the origin of cells which comprise lung fibrosis. A specific focus of this project is to determine the mechanisms and roles of cells originating from the bone marrow that are found in fibrotic lung lesions.

Funding:

American Heart Association - Grant to Dr. Madala

The role of TH-2 cytokines modulating inflammation and remodeling in the skin and lung

This project examines the role of interleukin-31(IL-31) in mediating skin and lung fibrosis and the relationship of IL-31 with other TH-2 cytokines and receptors including IL-4 and IL-13.

Funding:

Bristol-Myers Squibb
RO3 grant from the National Institutes of Health – Pending

Mechanisms of fibrosis resolution and irreversible remodeling

This project focuses on understanding the biology of how lung fibrosis resolves and the mechanisms whereby lung fibrosis becomes an irreversible scar.

Mechanisms of secondary pulmonary hypertension associated with pulmonary fibrosis

Pulmonary hypertension is a significant co-morbid factor in patients with pulmonary fibrosis. This project examines the mechanism whereby fibrotic lung tissue leads to pulmonary hypertension and explores pharmacologic and genetic mechanisms to reduce pulmonary hypertension in the presence of persistent fibrosis.

Research Project Images

Lung biopsy from a patient with severe cystic fibrosis lung disease taken at the time of lung transplantation. There is severe lung fibrosis extending out from the diseased airway extending into the alveolar areas of the lung. An airway has been obliterated from the chronic infection and inflammation and replaced with mesenchymal and inflammatory cells and extracellular matrix (arrow).

Control (A) and TGFα (B) mice were irradiated and reconstituted with green florescent protein (GFP) bone marrow cells. Lung cryosections from fibrotic regions following four weeks Dox show GFP+ bone marrow derived cells accumulate in the lungs of TGFα mice but not in CCSP/- mice.

Schemata (left) demonstrating genetic construct of transgenic mice overexpressing transforming growth factor-α (TGFa) which is overexpressed in airway and Type II epithelium only when mice are administered doxycycline (Dox). Pentachrome stain (right) demonstrating fibrosis is detected in adventitial regions of lung and progresses in the absence of detectable inflammation.

Trichrome stain from mice overexpressing TGFa for eight weeks demonstrating extensive adventitial (top) and pleural (bottom) fibrosis.

Hematoxylin and eosin stain of lung biopsy from a patients with idiopathic pulmonary fibrosis (IPF, left) and TGFα transgenic mice following six weeks of Dox (right). Fibrosis in IPF and TGFα mice extends inward from pleural surface (top panels). Lower panels demonstrate focal areas of fibroblasts expansion in lung parenchyma.

Cell signaling pathways activated downstream of TGFα/epidermal growth factor receptor (EGFR) which mediate fibroproliferation. Sites of specific pathway inhibition with pharmacologic inhibitors or genetic knockout mice are indicated that the laboratory is in the process of studying.

Smooth muscle actin stain on lung sections from mice overexpressing TGFa for four weeks demonstrating extensive pleural fibrosis (middle panel) which is inhibited when mice are pre-treated with the PI3K inhibitor PX-866.

To assess the efficacy of PI3K inhibition in established fibrosis, TGFa transgenic mice were treated with the PI3K inhibitor PX-866 after four weeks of Dox while remaining on Dox for an additional four weeks. Controls were treated with vehicle while remaining on Dox an additional four weeks. Dox induced expression of TGFa for eight weeks caused progressive weight loss in vehicle-treated mice (red line), while mice treated with PX-866 four weeks after TGFa induction did not have changes in body weight (green line), but weights remained below CCSP/- controls (blue line), and CCSP/TGFa mice which received four weeks of Dox, then taken off Dox and treated with four weeks of vehicle (gold line).

Hematoxylin and eosin stain on lung sections from mice overexpressing TGFa for seven weeks demonstrating extensive pleural fibrosis (middle panel) which is inhibited when mice are pre-treated with the mTOR inhibitor Rapamycin.

Representative photomicrographs of lung plural regions from TGFα mice stained for α smooth muscle actin (aSMA, green) and phosphorylated ERK1/2 (pERK, Red). Overlaid and enlarged images show a co-localization of signals for pERK1/2 with aSMA positive cells, indicating that pERK-positive cells were mesenchymal cells.