Effects of TGF-beta and glucocorticoids on map kinase phosphorylation, IL-6/IL-11 secretion and cell proliferation in primary cultures of human lung fibroblasts.
Transforming growth factor-beta1 (TGF-beta1) is crucially involved in the fibrotic events characterizing interstitial lung diseases (ILDs), as well as in the airway remodeling process typical of asthma. Within such a context, the aim of our study was to investigate, in primary cultures of normal and fibrotic human lung fibroblasts (HLFs), the effects of TGF-beta1 on mitogen-activated protein kinase (MAPK) phosphorylation, cell proliferation, and production of interleukins 6 (IL-6) and 11 (IL-11), in the presence or absence of a pretreatment with budesonide (BUD). MAPK phosphorylation was detected by Western blotting, cell viability and proliferation were evaluated using Trypan blue staining and [(3)H]-thymidine incorporation assay, respectively, and the release of IL-6 and IL-11 into cell culture supernatants was assessed by ELISA. TGF-beta1 (10 ng/ml) significantly stimulated MAPK phosphorylation (P < 0.01), and also enhanced cell proliferation as well as the secretion of both IL-6 and IL-11, which reached the highest increases at the 72nd h of cell exposure to this growth factor. All such effects were prevented by BUD (10(-8) M) and, with the exception of IL-6 release, also by a mixture of MAPK inhibitors. Therefore, our findings suggest that the fibrotic action exerted by TGF-beta1 in the lung is mediated at least in part by MAPK activation and by an increased synthesis of the profibrogenic cytokines IL-6 and IL-11; all these effects appear to be prevented by corticosteroids via inhibition of MAPK phosphorylation.
Pelaia
Girolamo
G
Department of Experimental and Clinical Medicine, University "Magna Graecia" of Catanzaro, Catanzaro, Italy.
Gallelli
Luca
L
D'Agostino
Bruno
B
Vatrella
Alessandro
A
Cuda
Giovanni
G
Fratto
Donatella
D
Renda
Teresa
T
Galderisi
Umberto
U
Piegari
Elena
E
Crimi
Nunzio
N
Rossi
Francesco
F
Caputi
Mario
M
Costanzo
Francesco S
FS
Vancheri
Carlo
C
Maselli
Rosario
R
Marsico
Serafino A
SA
D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D004789:Enzyme Activation / Q000187:drug effects / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism*; D005938:Glucocorticoids / Q000494:pharmacology*; D006801:Humans; D017370:Interleukin-11 / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D007378:Interleukins / Q000378:metabolism*; D008168:Lung / Q000187:drug effects / Q000378:metabolism*; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000502:physiology*; D019950:Mitogen-Activated Protein Kinase 1 / Q000187:drug effects / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D053773:Transforming Growth Factor beta1 / Q000494:pharmacology*; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology
D004791:Enzyme Inhibitors; D005938:Glucocorticoids; D017370:Interleukin-11; D015850:Interleukin-6; D007378:Interleukins; D053773:Transforming Growth Factor beta1; D019950:Mitogen-Activated Protein Kinase 1