Increased expression of gelatinases and collagenase in rat lungs exposed to 100% oxygen


Por: Pardo A., Selman M., Ridge K., Barrios R., Sznajder J.I.

Publicada: 1 ene 1996
Resumen:
Exposure of adult rats to 100% O2 produces a lethal injury by 72 h. We reasoned that matrix metalloproteinases participate in the pathogenesis of hyperoxic lung injury. To that end we studied the expression and activity of gelatinases A and B and interstitial collagenase in lung tissues and bronchoalveolar lavage fluids (BALF) of rats exposed to 100% oxygen for 60 h. Gelatin zymography of BALF samples revealed a ~72 kDa molecular species both in controls and oxygen-exposed animals. In addition, BALF from hyperoxic rats exhibited a 95-kDa gelatinase. Likewise, BALF total gelatinolytic and collagenolytic activities were significantly increased in oxygen-exposed rats. In situ hybridization revealed an increase in type IV collagenases as well as interstitial collagenase mRNAs in the oxygen-exposed lungs. The three enzymes were expressed by alveolar macrophages, and in variable degrees by interstitial and alveolar epithelial cells. Immunoreactive gelatinase B and collagenase paralleled the cell localization of the mRNAs but were also detected in the alveolar walls and interstitium. In situ zymography showed gelatinolytic activity in frozen sections of oxygen-exposed lungs but not in normal lungs. The upregulation of these metalloproteinases during acute exposure to 100% O2 suggests that they might contribute to hyperoxic lung damage through the degradation of extracellular matrix components.

Filiaciones:
Pardo A.:
 Facultad de Ciencias, UNAM, Apartado Postal 21-630, México DF, CP 04030, Mexico
ISSN: 1073449X
Editorial
AMER THORACIC SOC, 61 BROADWAY, FL 4, NEW YORK, NY 10006 USA, Estados Unidos America
Tipo de documento: Article
Volumen: 154 Número: 4 I
Páginas: 1067-1075
WOS Id: A1996VN22100040
ID de PubMed: 8887609