[The effects of transforming growth factor alpha and beta 1 on the proliferation of alveolar type II cells in vitro].
OBJECTIVE
To investigate the effect of transforming growth factor alpha and beta(1) (TGFalpha and beta(1)) on the proliferation of alveolar type II cells in vitro and the molecular mechanism related.


METHODS
(3)H-TdR incorporation and cell counting for the assay of cell growth; dot blot, in situ hybridization, and immunohistochemical methods for analysing the expression of cyclin D1 and cycle-dependent kinase 4 (CDK4) genes.


RESULTS
With increasing of the concentration of TGFalpha and beta(1) (0.01 ng-100 ng/ml), TGFalpha enabled to increase (3)H-TdR incorporation and the number of alveolar type II cells, while the effect of TGFbeta(1) was opposite and both effects were dose-dependent (P < 0.01). TGFalpha-treated cells decreased the expression of CDK4 mRNA, and the relevant in comparing with the control (P < 0.01). On the contrary, TGFbeta(1)-treated cells decreased the expression of CDK4 mRNA), CDK4 as well as the cyclin D1 proteins (P < 0.05).


CONCLUSIONS
Both TGFalpha and beta(1) were considered implicated in the regulation of proliferation of cultured alveolar type II cells isolated from the adult rats and CDK4 might be a common target against TGFalpha and beta(1) signals.
Zeng
Q
Q
Department of Pathology, Hunan Medical University, Changsha 410078.
Qian
Z
Z
Su
T
T
Sun
Q
Q
Jiang
H
H
D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D051358:Cyclin-Dependent Kinase 4; D018844:Cyclin-Dependent Kinases / Q000235:genetics; D004305:Dose-Response Relationship, Drug; D005786:Gene Expression Regulation / Q000187:drug effects; D008297:Male; D011518:Proto-Oncogene Proteins; D011650:Pulmonary Alveoli / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D016211:Transforming Growth Factor alpha / Q000494:pharmacology*; D016212:Transforming Growth Factor beta / Q000494:pharmacology*; D053773:Transforming Growth Factor beta1
D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; C508962:Tgfb1 protein, rat; D016211:Transforming Growth Factor alpha; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; C495903:Cdk4 protein, rat; D051358:Cyclin-Dependent Kinase 4; D018844:Cyclin-Dependent Kinases