PT  - JOURNAL ARTICLE
AU  - Elena Tourkina
AU  - Mathieu Richard
AU  - James Oates
AU  - Ann Hofbauer
AU  - Michael Bonner
AU  - Pal Gööz
AU  - Richard Visconti
AU  - Jing Zhang
AU  - Sergei Znoyko
AU  - Corey M Hatfield
AU  - Richard M Silver
AU  - Stanley Hoffman
TI  - Caveolin-1 regulates leucocyte behaviour in fibrotic lung disease
AID  - 10.1136/ard.2009.117580
DP  - 2010 Jun 01
TA  - Annals of the Rheumatic Diseases
PG  - 1220--1226
VI  - 69
IP  - 6
4099  - http://ard.bmj.com/content/69/6/1220.short
4100  - http://ard.bmj.com/content/69/6/1220.full
SO  - Ann Rheum Dis2010 Jun 01; 69
AB  - Objectives Reduced caveolin-1 levels in lung fibroblasts from patients with scleroderma and the lungs of bleomycin-treated mice promote collagen overexpression and lung fibrosis. This study was undertaken to determine whether caveolin-1 is deficient in leucocytes from bleomycin-treated mice and patients with scleroderma and to examine the consequences of this deficiency and its reversal. Methods Mice or cells received the caveolin-1 scaffolding domain (CSD) peptide to reverse the pathological effects of reduced caveolin-1 expression. In bleomycin-treated mice, the levels of caveolin-1 in leucocytes and the effect of CSD peptide on leucocyte accumulation in lung tissue were examined. To validate the results in human disease and to identify caveolin-1-regulated molecular mechanisms, monocytes and neutrophils were isolated from patients with scleroderma and control subjects and caveolin-1, extracellular signal-regulated protein kinase (ERK), c-Jun N-terminal kinase (JNK), p38, CXC chemokine receptor 4 (CXCR4) and matrix metalloproteinase 9 (MMP-9) expression/activation were evaluated. These parameters were also studied in monocytes treated with cytokines or CSD peptide. Results Leucocyte caveolin-1 is important in lung fibrosis. In bleomycin-treated mice, caveolin-1 expression was diminished in monocytes and CSD peptide inhibited leucocyte recruitment into the lungs. These observations are relevant to human disease. Monocytes and neutrophils from patients with scleroderma contained less caveolin-1 and more activated ERK, JNK and p38 than those from control subjects. Treatment with CSD peptide reversed ERK, JNK and p38 hyperactivation. Scleroderma monocytes also overexpressed CXCR4 and MMP-9, which was inhibited by the CSD peptide. Cytokine treatment of normal monocytes caused adoption of the scleroderma phenotype (low caveolin-1, high CXCR4 and MMP-9 and signalling molecule hyperactivation). Conclusions Caveolin-1 downregulation in leucocytes contributes to fibrotic lung disease, highlighting caveolin-1 as a promising therapeutic target in scleroderma.