[Proliferation and wound healing of retinal pigment epithelium cells in vitro. Effect of human thrombocyte concentrate, serum and PDGF].
OBJECTIVE
Biological agents like human serum or autologous platelets have recently been employed as adjuvants for macular hole surgery. However, the role of these agents on the retinal cellular level remains unclear. In the present study, we investigated the effect of human platelets, serum and PDGF on RPE migration and proliferation in cell culture.


METHODS
Human RPE were cultured in DMEM + 2% FCS and experiments performed at passages 2-4. Human platelet concentrate (PC) and serum (HS) were isolated from blood of patients previewed for macular hole surgery; human PDGF-BB was from Pepro Tech. PC and HS at protein concentrations ranging from 50-1000 micrograms/ml and PDGF at 1 and 10 ng/ml were added to 5000 cells/well in the proliferation assay and to a confluent RPE monolayer on which a central mechanical "wound" (5 mm diameter) was made. Incubation times ranged from 1 h to 5 days. Cell numbers at D 5 were indirectly determined by protein measurements. In the wound model, the cells inside the wound area were counted and results compared to the control cultures that received no supplements.


RESULTS
Cell proliferation was significantly stimulated over controls by all concentrations of PC, HS and PDGF with any incubation time. Compared to PC and PDGF, HS revealed less proliferation after 1-6 h of incubation; there was no significant difference from PC with other incubation times. In the wound model, both PC and PDGF significantly increased the number of cells migrating into the denuded area after 1 h incubation with the culture medium; longer incubation times had no further effect compared to controls.


CONCLUSIONS
The present study is the first to demonstrate that human platelet concentrate induces proliferation and migration of RPE cells in vitro. However, PDGF, a growth factor which is abundantly present in platelets, was found to be at least equally effective. We assume that the majority of the mitogenic effect of platelet concentrate is due to PDGF.
Velhagen
K H
KH
Augenklinik der Charité, Humboldt-Universität Berlin.
Druegg
A
A
Rieck
P
P
D001792:Blood Platelets / Q000502:physiology*; D001798:Blood Proteins / Q000502:physiology*; D002454:Cell Differentiation / Q000502:physiology*; D002478:Cells, Cultured; D017077:Culture Media, Conditioned; D006801:Humans; D010857:Pigment Epithelium of Eye / Q000166:cytology*; D010982:Platelet-Derived Growth Factor / Q000502:physiology*; D014945:Wound Healing / Q000502:physiology*
D001798:Blood Proteins; D017077:Culture Media, Conditioned; D010982:Platelet-Derived Growth Factor