[Latent TGFbeta1 activation in the lung irradiated in vivo].
OBJECTIVE
assess the latent and active TGFb1 localization in the lung, whether or not radiation induces latent TGFbeta1 activation, and the distribution of collagen fibers in the irradiated lung.


METHODS
Thirty two C57BL mice were randomly assigned in two groups: GI (non irradiated animals) and GII (irradiated animals). The mice from GII received a single whole - body radiation dose of 7Gy, using a 60Co source at a dose rate of 0.97 Gy/min. They were sacrificed by cervical dislocation at 1, 14, 30 and 90 days after radiation.


RESULTS
The irradiated lungs showed: 1) vascular congestion and thickness of the alveolar septa 30 days and more intense 90 days after irradiation; 2) significant increase of collagen deposition in all time periods after irradiation; 3) weak latent TGFbeta1 activation 1 day and strong activation 14 days after irradiation in the bronchi and alveoli. Our results suggest that some bronchial and alveolar cells may have a role in the complex process of radiation-induced lung fibrosis acting as cellular sources of active TGFbeta.
Mattos
Marcos Duarte
MD
Laboratório de Radioterapia Experimental Prof. Dr. Camillo Segreto - Setor de Radioterapia do Departamento de Medicina da Universidade Federal de São Paulo, São Paulo, SP, Brasil.
Kimura
Edna Teruko
ET
Silva
Maria Regina Régis
MR
Egami
Mizue Imoto
MI
Segreto
Roberto Araújo
RA
Segreto
Helena Regina Comodo
HR
D030201:Activin Receptors, Type I / Q000032:analysis / Q000378:metabolism*; D000818:Animals; D001980:Bronchi / Q000528:radiation effects; D002352:Carrier Proteins / Q000378:metabolism*; D003094:Collagen / Q000378:metabolism; D004307:Dose-Response Relationship, Radiation; D007150:Immunohistochemistry; D047908:Intracellular Signaling Peptides and Proteins; D053779:Latent TGF-beta Binding Proteins; D008168:Lung / Q000378:metabolism / Q000528:radiation effects*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D017346:Protein Serine-Threonine Kinases; D011650:Pulmonary Alveoli / Q000378:metabolism / Q000528:radiation effects; D011658:Pulmonary Fibrosis / Q000209:etiology / Q000378:metabolism*; D011833:Radiation Injuries, Experimental / Q000378:metabolism*; D000077293:Receptor, Transforming Growth Factor-beta Type I; D018125:Receptors, Transforming Growth Factor beta / Q000032:analysis / Q000378:metabolism*; D013997:Time Factors; D014916:Whole-Body Irradiation
D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; D053779:Latent TGF-beta Binding Proteins; D018125:Receptors, Transforming Growth Factor beta; D003094:Collagen; D017346:Protein Serine-Threonine Kinases; D030201:Activin Receptors, Type I; D000077293:Receptor, Transforming Growth Factor-beta Type I