Am. J. Respir. Crit. Care Med.,
Volume 164, Number 8, October 2001, 1519-1525
Collagens I and III in a Porcine Bronchial Model of
Obliterative Bronchiolitis
HANNI S.
ALHO,
KAIJA A.
INKINEN,
ULLA-STINA
SALMINEN,
PAULA K.
MAASILTA,
EERO I.
TASKINEN,
VIRPI
GLUMOFF,
EERO I.
VUORIO,
TUIJA S.
IKONEN,
and
ARI L. J.
HARJULA
Department of Surgery, and Transplant Unit, Research Laboratory, and Department of Pulmonary Medicine, and of Transplantation Laboratory,
Helsinki University Hospital, Helsinki, Finland; Department of Pediatrics and Biocenter Oulu, University of Oulu, Oulu, Finland, and Department of
Medical Biochemistry and Molecular Biology, University of Turku, Turku, Finland
The main extracellular matrix components of the lung, type I and
III collagens, were studied in chronic allograft rejection developing in a porcine heterotopic bronchial transplantation model. Specific porcine complementary DNA probes were constructed for detection of the expression of type I and III procollagen messenger
RNAs in the bronchial wall structures and in the obliterative plug
by in situ hybridization. In autografts, and in allografts immunosuppressed with 40-O-(2-hydroxyethyl)-rapamycin, cyclosporine A, and methylprednisolone, no histological changes of obliterative bronchiolitis (OB) developed, and the number of fibroblast-like cells
expressing type I and III procollagen mRNA remained low. In nontreated allografts obliterating within 21 d, a preponderance of fibroblast-like cells showing positivity for type III procollagen mRNA
existed in the obliterative plug and bronchial wall. This study
shows for the first time the temporal and spatial activation of type
I and III procollagen genes during the course of obliterative bronchiolitis. The number of cells expressing procollagen III mRNA increased parallel to developing obliteration and fibrosis in nontreated allografts, whereas autografts and immunosuppressed allografts exhibited no such trend. This finding suggests a positive association between type III collagen mRNA expression in fibroblast-like cells and development of obliterative bronchiolitis.
