Retinal glial cells stimulate microvascular pericyte proliferation via fibroblast growth factor and platelet-derived growth factor in vitro.
OBJECTIVE
To investigate whether retinal glial cells (RGCs), which are believed to play an important role in the development and maintenance of microvessels, stimulate the proliferation of retinal bovine microvascular pericytes, an essential component of the vessels.


METHODS
Conditioned medium (CM) was collected from a primary culture of RGC obtained from chick embryonic retina. The cell number was assayed after stimulation by RGC-CM. Also, by neutralizing antibody and reverse transcription polymerase chain reaction (RT-PCR), we tried to identify which factor of the RGCs contributes to the pericyte stimulation.


RESULTS
Pericyte proliferation was stimulated by RGC-CM in a dose-dependent manner. Platelet-derived growth factor-BB (PDGF-BB), acidic fibroblast growth factor (aFGF), and basic fibroblast growth factor (bFGF) stimulated pericyte proliferation; however, PDGF-AA, transforming growth factor-beta2 (TGF-beta2), and vascular endothelial growth factor (VEGF) did not. The RGC-CM-dependent stimulative effect was blocked, in part, by the neutralizing antibodies for aFGF, bFGF, and PDGF. A mixture of these three antibodies completely blocked the stimulation. RT-PCR revealed that RNA for aFGF, bFGF, and TGF-beta2 were expressed in RGCs.


CONCLUSIONS
Pericyte growth is stimulated in vitro by RGC-CM through aFGF, bFGF, PDGF-BB, at least in part. This finding suggests that RGCs may modulate in vivo pericyte cell growth through these three growth factors.
Ikuno
Yasushi
Y
Department of Ophthalmology, Osaka University Medical School, Osaka, Japan.
Hibino
Sawako
S
Bando
Hajime
H
Kawasaki
Yoshimi
Y
Nakamura
Takao
T
Tano
Yasuo
Y
D000818:Animals; D000077214:Becaplermin; D002196:Capillaries / Q000166:cytology; D002417:Cattle; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D002642:Chick Embryo; D017077:Culture Media, Conditioned / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D016220:Fibroblast Growth Factor 1 / Q000235:genetics / Q000494:pharmacology*; D016222:Fibroblast Growth Factor 2 / Q000235:genetics / Q000494:pharmacology*; D006801:Humans; D009457:Neuroglia / Q000502:physiology*; D020286:Pericytes / Q000166:cytology*; D010982:Platelet-Derived Growth Factor / Q000235:genetics / Q000494:pharmacology*; D020574:Proto-Oncogene Proteins c-sis; D012333:RNA, Messenger / Q000378:metabolism; D012160:Retina / Q000166:cytology*; D012165:Retinal Ganglion Cells / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D017077:Culture Media, Conditioned; D010982:Platelet-Derived Growth Factor; D020574:Proto-Oncogene Proteins c-sis; D012333:RNA, Messenger; D016222:Fibroblast Growth Factor 2; D016220:Fibroblast Growth Factor 1; D000077214:Becaplermin