Growth hormone prevents apoptosis through activation of nuclear factor-kappaB in interleukin-3-dependent Ba/F3 cell line.
The pro-B Ba/F3 cell line requires interleukin-3 and serum for growth, and their removal results in cell apoptosis. Ba/F3 cells transfected with the GH receptor (GHR) cDNA become able to proliferate in response to GH. To investigate the role of GH in the control of apoptosis, Ba/F3 cells expressing either the wild-type rat GHR (Ba/F3 GHR) or a mutated rat GHR (Ba/F3 ILV/T) were used. We show that Ba/F3 GHR cells, but not parental Ba/F3 or Ba/F3 ILV/T cells, were able to survive in the absence of growth factor. Furthermore, an autocrine/paracrine mode of GH action was suggested by the demonstration that Ba/F3 cells produce GH, and that addition of GH antagonists (B2036 and G120K) promotes apoptosis of Ba/F3 GHR cells. Consistent with survival, the levels of both antiapoptotic proteins Bcl-2 and Bag-1 were maintained in Ba/F3 GHR cells, but not in parental Ba/F3 cells upon growth factor deprivation. Constitutive activation of the transcription factor nuclear factor-kappaB (NF-kappaB), which has been shown to promote cell survival, was sustained in Ba/F3 GHR cells, whereas no NF-kappaB activation was detected in parental Ba/F3 cells in the absence of growth factor. Furthermore, addition of GH induced NF-kappaB DNA binding activity in Ba/F3 GHR cells. Overexpression of the mutated IkappaB alpha (A32/36) protein, known to inhibit NF-kappaB activity, resulted in death of growth factor-deprived Ba/F3 GHR cells, and addition of GH was no longer able to rescue these cells from apoptosis. Together, our results provide evidence for a new GH-mediated pathway that initiates a survival signal through activation of the transcription factor NF-kappaB and sustained levels of the antiapoptotic proteins Bcl-2 and Bag-1.
Jeay
S
S
INSERM Unité 344, Endocrinologie Moléculaire, Faculté de Médecine Necker, Paris, France.
Sonenshein
G E
GE
Postel-Vinay
M C
MC
Baixeras
E
E
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D019898:Autocrine Communication; D002352:Carrier Proteins / Q000096:biosynthesis; D002417:Cattle; D002453:Cell Cycle / Q000187:drug effects; D002460:Cell Line; D003470:Culture Media / Q000494:pharmacology; D018076:DNA, Complementary / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000502:physiology; D003864:Depression, Chemical; D019281:Dimerization; D019254:Genes, bcl-2; D013006:Growth Hormone / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000187:drug effects*; D020672:I-kappa B Proteins; D007377:Interleukin-3 / Q000494:pharmacology*; D051379:Mice; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000502:physiology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis; D051381:Rats; D011986:Receptors, Somatotropin / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors; D014158:Transcription, Genetic / Q000187:drug effects*; D014162:Transfection; D051020:bcl-X Protein
C091732:BCL2-associated athanogene 1 protein; C494812:Bcl2l1 protein, mouse; C494813:Bcl2l1 protein, rat; D002352:Carrier Proteins; D003470:Culture Media; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D020672:I-kappa B Proteins; D007377:Interleukin-3; D016328:NF-kappa B; C000606205:Nfkbia protein, mouse; C000606206:Nfkbia protein, rat; D019253:Proto-Oncogene Proteins c-bcl-2; D011986:Receptors, Somatotropin; D014157:Transcription Factors; D051020:bcl-X Protein; D000072000:NF-KappaB Inhibitor alpha; D013006:Growth Hormone