TGF-beta2 inhibits growth of uveal melanocytes at physiological concentrations.
The effect of TGF-beta2 on growth of uveal melanocytes in vitro was studied and the dose-dependent inhibitory effect of TGF-beta2 was compared with the known concentration of TGF-beta2 in aqueous humor. Uveal melanocytes were isolated and cultured with medium supplemented with cAMP elevating agents and basic fibroblast growth factor. The uveal melanocytes were plated into multi-well plates. After 24 hr, TGF-beta2 was added to the medium in various concentrations. After 5 days, the cells were detached, counted and compared to the controls. The effect of TGF-beta2 on DNA synthesis (as evaluated by uptake of bromodeoxyuridine) were also tested. TGF-beta2 inhibited growth and DNA synthesis of cultured uveal melanocytes in a dose-dependent manner at concentrations from 0.03-10.0 ng ml-1. The growth-inhibition of TGF-beta2 was present even in serum-free medium. TGF-beta2 had little or no effect on melanogenesis of cultured uveal melanocytes. The serum used for cultivation did not contain active TGF-beta1 or TGF-beta2 as measured by immunoassay. The known amount of active TGF-beta2 in aqueous humor (0.2-0.4 ng ml-1) is sufficient to inhibit the growth of uveal melanocytes. It indicates that TGF-beta2 is a potent growth inhibit factor of uveal melanocytes and may play an important role in maintaining the non-proliferative, relatively quiescence status of uveal melanocytes in vivo.
Hu
D N
DN
New York Medical College, The New York Eye and Ear Infirmary, 310 E. 14th Street, New York, NY 10003, USA.
McCormick
S A
SA
Lin
A Y
AY
Lin
J Y
JY
D000328:Adult; D001973:Bromodeoxyuridine / Q000493:pharmacokinetics; D018929:Cell Culture Techniques; D002455:Cell Division / Q000187:drug effects; D004247:DNA / Q000096:biosynthesis; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008543:Melanins / Q000096:biosynthesis; D008544:Melanocytes / Q000187:drug effects* / Q000378:metabolism; D011994:Recombinant Proteins / Q000494:pharmacology; D016212:Transforming Growth Factor beta / Q000494:pharmacology*; D014602:Uvea / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism
D008543:Melanins; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; D004247:DNA; D001973:Bromodeoxyuridine