Mechanical strain enhances proteoglycan message in fibroblasts from asthmatic subjects.
BACKGROUND
Remodelling of the asthmatic airway includes increased deposition of proteoglycan (PG) molecules. One of the stimuli driving airway remodelling may be excessive mechanical stimulation.


OBJECTIVE
We hypothesized that fibroblasts from asthmatic patients would respond to excessive mechanical strain with up-regulation of message for PGs.


METHODS
We obtained fibroblasts from asthmatic patients (AF) and normal volunteers (NF) using endobronchial biopsy. Cells were maintained in culture until the fifth passage and then grown on a flexible collagen-coated membrane. Using the Flexercell device, cells were then subjected to cyclic stretch at 30% amplitude at 1 Hz for 24 h. Control cells were unstrained. Total RNA was extracted from the cell layer and quantitative RT-PCR performed for decorin, lumican and versican mRNA.


RESULTS
In unstrained cells, the expression of decorin mRNA was greater in AF than NF. With strain, NF showed increased expression of versican mRNA and AF showed increased expression of versican and decorin mRNA. The relative increase in versican mRNA expression with strain was greater in AF than NF.


CONCLUSIONS
These data support the hypothesis that proteoglycan message is increased in asthmatic fibroblasts subject to mechanical strain. This finding has implications for the mechanisms governing airway wall remodelling in asthma.
Ludwig
M S
MS
Meakins Christie Laboratories, McGill University Hospital Center, Montreal, Quebec, Canada. mara.ludwig@mcgill.ca
Ftouhi-Paquin
N
N
Huang
W
W
Pagé
N
N
Chakir
J
J
Hamid
Q
Q
D000328:Adult; D000704:Analysis of Variance; D001249:Asthma / Q000378:metabolism* / Q000473:pathology; D001980:Bronchi / Q000473:pathology; D016022:Case-Control Studies; D005260:Female; D005347:Fibroblasts / Q000378:metabolism*; D006801:Humans; D008297:Male; D011509:Proteoglycans / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013314:Stress, Mechanical
D011509:Proteoglycans