Mouse Model Sheds Light on Scleroderma Lung Damage
Transforming growth factor Β may determine fibrosis; fibroblasts may influence AEC injury
MONDAY, April 21 (HealthDay News) -- Transforming growth factor Β may play a key role in determining fibrosis after epithelial lung injury, and lung fibroblasts may regulate the response of alveolar epithelial cells (AECs) to injury, offering insight into factors underlying scleroderma-associated pulmonary fibrosis (SSc-PF), according to research in the April Arthritis & Rheumatism.
Rachel K. Hoyles, MRCP, of the Royal Free and University College Medical School in London and colleagues compared lung injuries from saline and bleomycin in both wild-type mice and a transgenic mouse model of scleroderma with fibroblast-specific perturbation of transforming growth factor Β signaling (TΒRIIΔk-fib mice).
Following bleomycin treatment, lungs from transgenic mice had more fibroproliferation, myofibroblast persistence and impaired hyperplasia and greater apoptosis of type II AECs. The lungs from transgenic mice after saline injury showed similarities to those from wild-type mice after bleomycin injury, pointing to greater susceptibility to minor epithelial injury in transgenic mice. Lingering fibrosis in transgenic mice treated with bleomycin appeared to be independent of ongoing neutrophil inflammation.
"The current study provides significant insights into pathogenic mechanisms in SSc-PF and highlights a potential key role of lung fibroblasts in regulating the response of AECs to injury. The results are also consistent with a central role for TGFΒ in determining fibrosis," the authors write.
The corresponding author of the study reports financial relationships with Actelion, Encysive and Genzyme.