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Proteoglycans in granulomatous lung diseases
E S Bensadoun1, A K Burke, J C Hogg
1Dept of Medicine, University of British Columbia Pulmonary Research Laboratory, St. Paul's Hospital, Vancouver, Canada.
The European Respiratory Journal
|March 11, 1998
Summary
Versican, a proteoglycan, is deposited in the early stages of lung fibrosis, both granulomatous and non-granulomatous. This versican-rich matrix is where myofibroblasts synthesize collagen, suggesting versican influences lung repair.
Area of Science:
- Pulmonary Medicine
- Cell Biology
- Extracellular Matrix Research
Background:
- Early collagen synthesis in lung fibrosis involves myofibroblasts and versican.
- Chronic inflammation drives collagen synthesis in fibrotic lung conditions.
Purpose of the Study:
- To investigate the localization of proteoglycans and collagen in granulomatous lung diseases.
- To determine versican's association with collagen synthesis in sarcoidosis, extrinsic allergic alveolitis (EAA), and tuberculosis (TB).
Main Methods:
- Histochemistry for glycosaminoglycans and collagen.
- Immunohistochemistry for versican, decorin, biglycan, hyaluronan, type I procollagen, and alpha-smooth muscle actin.
- Analysis of lung tissue from sarcoidosis, EAA, and TB patients.
Main Results:
- Versican and collagen were found in the connective tissue surrounding granulomas in sarcoidosis, EAA, and TB.
- Myofibroblasts in versican-rich areas showed intracellular type I procollagen staining.
- Decorin localized intracellularly in granuloma epithelioid cells and some myofibroblasts.
Conclusions:
- Versican deposition is specific to the early remodeling of both granulomatous and non-granulomatous lung diseases.
- Collagen synthesis occurs within a versican-rich provisional matrix in various lung fibrotic conditions.
- Versican may play a role in the progression of lung repair after injury.