PMID- 1639863
OWN - NLM
STAT- MEDLINE
DCOM- 19920828
LR  - 20031114
IS  - 0021-9541 (Print)
IS  - 0021-9541 (Linking)
VI  - 152
IP  - 2
DP  - 1992 Aug
TI  - Changes in responsiveness of rat tracheal epithelial cells to transforming growth 
      factor-beta 1 with time in culture.
PG  - 281-91
AB  - Primary rat tracheal epithelial (RTE) cell cultures have previously been shown to 
      be highly sensitive to growth inhibition by transforming growth factor-beta 1 
      (TGF beta 1) when treated within 1-2 days after plating. The purpose of the 
      present studies was to examine the effects of TGF beta 1 on the growth of RTE 
      cells as a function of time in culture. We found that the sensitivity of RTE 
      cells to growth inhibition by TGF beta 1 decreased dramatically as the cultures 
      aged. The IC50 for inhibition of colony forming efficiency was 0.18 pM when TGF 
      beta 1 was added 24 h after cell plating. When TGF beta 1 treatment was begun on 
      day 5 of culture, the IC50 was 3-4 pM as measured by inhibition of growth (cell 
      number) and DNA synthesis. However, when TGF beta 1 was begun on day 19, the IC50 
      was 65 pM or greater than 500 pM, depending on whether inhibition of growth or 
      DNA synthesis, respectively, was measured. TGF beta 1 accelerated cell death, as 
      measured by exfoliation of cells, and inhibited cell proliferation. The decrease 
      in responsiveness to TGF beta 1 in late cultures was shown to be dependent on 
      culture age as well as on cell density. No evidence was found for inactivation or 
      degradation of the added TGF beta 1 by the late stage cultures. Cells subcultured 
      from late stage primary cultures remained less responsive to TGF beta 1 than 
      subcultured cells from early cultures. Similar to its effect on proliferation, 
      TGF beta 1 down-regulated the expression of two proliferation-related genes, 
      c-myc and transforming growth factor-alpha, in early but not late RTE cell 
      cultures. On the other hand, fibronectin expression was increased by TGF beta 1 
      by about twofold at both early and late times in culture. This indicates that the 
      changes in TGF beta 1 responsiveness with time in culture are selective, 
      apparently affecting primarily proliferation-related events.
FAU - Rundhaug, J E
AU  - Rundhaug JE
AD  - Laboratory of Pulmonary Pathobiology, National Institute of Environmental Health 
      Sciences, Research Triangle Park, North Carolina 27709.
FAU - Gray, T
AU  - Gray T
FAU - Steigerwalt, R W
AU  - Steigerwalt RW
FAU - Nettesheim, P
AU  - Nettesheim P
LA  - eng
PT  - Journal Article
PL  - United States
TA  - J Cell Physiol
JT  - Journal of cellular physiology
JID - 0050222
RN  - 0 (Transforming Growth Factor beta)
SB  - IM
MH  - Animals
MH  - Cell Count
MH  - Cell Division/drug effects
MH  - Cells, Cultured
MH  - Cytological Techniques
MH  - Dose-Response Relationship, Drug
MH  - Epithelial Cells
MH  - Epithelium/drug effects/physiology
MH  - Rats
MH  - Stem Cells/physiology
MH  - Time Factors
MH  - Trachea/cytology/*drug effects/physiology
MH  - Transforming Growth Factor beta/metabolism/*pharmacology
EDAT- 1992/08/01 00:00
MHDA- 1992/08/01 00:01
CRDT- 1992/08/01 00:00
PHST- 1992/08/01 00:00 [pubmed]
PHST- 1992/08/01 00:01 [medline]
PHST- 1992/08/01 00:00 [entrez]
AID - 10.1002/jcp.1041520209 [doi]
PST - ppublish
SO  - J Cell Physiol. 1992 Aug;152(2):281-91. doi: 10.1002/jcp.1041520209.