Transforming growth factor-betas inhibit mitogen-stimulated proliferation of astrocytes.
We have studied the influence of three members of the transforming growth factor-beta (TGF-beta) family of multifunctional growth factors on the proliferation of cultured astrocytes isolated from newborn mouse cerebral cortex. Although TGF-beta s 1, 2, and 3 cause only a small reduction in the low level of astrocyte proliferation occurring in chemically defined medium, they each inhibit the effects of five astrocyte mitogens (bFGF, EGF, PDGF, IL-1 alpha, and IL-2). Inhibition is observed when astrocytes are exposed to mitogen and TGF-beta at the same time and when they are exposed to TGF-beta prior to, and separately from, mitogen. This latter effect appears to be due to the binding of TGF-beta s to astrocyte-secreted extracellular matrix. These findings raise the possibility that TGF-beta may co-operate with other growth factors to control astrocyte proliferation in vivo.
Hunter
K E
KE
Department of Anatomy, St. George's Hospital Medical School, London.
Sporn
M B
MB
Davies
A M
AM
D000818:Animals; D000831:Animals, Newborn; D001253:Astrocytes / Q000187:drug effects*; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology; D004261:DNA Replication / Q000187:drug effects; D003864:Depression, Chemical; D005109:Extracellular Matrix / Q000378:metabolism; D006133:Growth Substances / Q000494:pharmacology; D007378:Interleukins / Q000037:antagonists & inhibitors / Q000494:pharmacology; D051379:Mice; D008934:Mitogens / Q000037:antagonists & inhibitors*; D016212:Transforming Growth Factor beta / Q000378:metabolism / Q000494:pharmacology*
D006133:Growth Substances; D007378:Interleukins; D008934:Mitogens; D016212:Transforming Growth Factor beta