Expression of the stress-induced p8 mRNA is transiently activated after culture medium change.
We report here that the mere fact of changing culture medium for fresh medium induced in several cell lines the expression of stress-activated genes including protein kinases p38, JNK and ERK1/2 and the transcription factor C/EBPbeta. As a consequence, p8, a gene induced by stress in several tissues, was strongly up-regulated. Induction did not occur after change for cell-conditioned medium. Induction was however transient, with a peak at 60 min for p38, at 15-30 min for JNK and at 15 min for ERK1/2, at 2-3 hours for C/EBPbeta and at 4-6 hours for p8. Repression of the induction was due to the secretion of thermolabile molecule(s) that progressively conditioned the medium. As low as 25% of conditioned medium added to fresh culture medium was sufficient to abolish the stress response. Taken together, our data indicate that the renewal of culture medium induces a transient cellular stress that may be a source of artifacts in experiments performed shortly after a change of culture medium.
Garcia-Montero
A
A
Centre de Recherche INSERM, EMI 0116, Marseille/France.
Vasseur
S
S
Mallo
G V
GV
Soubeyran
P
P
Dagorn
J C
JC
Iovanna
J L
JL
D016475:3T3 Cells; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins; D022762:CCAAT-Enhancer-Binding Proteins; D017077:Culture Media, Conditioned / Q000737:chemistry / Q000494:pharmacology*; D004268:DNA-Binding Proteins / Q000235:genetics*; D015870:Gene Expression / Q000187:drug effects* / Q000502:physiology; D006133:Growth Substances / Q000235:genetics*; D019073:HT29 Cells; D006367:HeLa Cells; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; D051379:Mice; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009363:Neoplasm Proteins; D012333:RNA, Messenger / Q000032:analysis; D014157:Transcription Factors / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases
D051792:Basic Helix-Loop-Helix Proteins; D022762:CCAAT-Enhancer-Binding Proteins; D017077:Culture Media, Conditioned; D004268:DNA-Binding Proteins; D006133:Growth Substances; D048031:JNK Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020929:Mitogen-Activated Protein Kinase Kinases; D020928:Mitogen-Activated Protein Kinases; D009363:Neoplasm Proteins; D012333:RNA, Messenger; D014157:Transcription Factors; D048051:p38 Mitogen-Activated Protein Kinases; C083058:C-EPB transcription factor; C491643:NUPR1 protein, human; C491644:Nupr1 protein, mouse