Analysis of expression of growth factor receptors in replicatively and oxidatively senescent human fibroblasts.
Replicatively and oxidatively senescent human fibroblasts demonstrate an impaired response to mitogens. To investigate whether this is due to downregulation of growth factor receptors we examined their expression in these two types of senescence. mRNA and protein levels of the insulin receptor and platelet-derived growth factor (PDGF) alpha-receptor decreased in replicatively senescent cells. The PDGF beta-receptor and insulin-like growth factor 1 receptor at the protein level also decreased but remained readily detectable. However, these major growth factor receptors remained unchanged in oxidatively premature senescent cells. This suggests that mechanisms underlying diminished responsiveness to mitogens might be different in replicative senescence and oxidatively premature senescence.
Chen
Jian-Hua
JH
Department of Clinical Biochemistry, University of Cambridge, Addenbrooke's Hospital, Level 4, Hills Road, Cambridge CB2 2QR, United Kingdom. jhc36@cam.ac.uk
Ozanne
Susan E
SE
Hales
C Nicholas
CN
D002455:Cell Division; D016922:Cellular Senescence; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism / Q000502:physiology; D006801:Humans; D018384:Oxidative Stress; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D017526:Receptor, IGF Type 1 / Q000235:genetics / Q000378:metabolism*; D011972:Receptor, Insulin / Q000235:genetics / Q000378:metabolism*; D020796:Receptor, Platelet-Derived Growth Factor alpha / Q000235:genetics / Q000378:metabolism*; D020797:Receptor, Platelet-Derived Growth Factor beta / Q000235:genetics / Q000378:metabolism*
D012333:RNA, Messenger; D017526:Receptor, IGF Type 1; D011972:Receptor, Insulin; D020796:Receptor, Platelet-Derived Growth Factor alpha; D020797:Receptor, Platelet-Derived Growth Factor beta