Expression of platelet-derived growth factor in the developing cochlea of rats

Abstract

OBJECTIVE: Platelet-derived growth factor (PDGF) is involved in the control of cell proliferation, differentiation and survival in various tissues of vertebrates. However, little is known about the expression of PDGF in the developing cochlea of rodents. MATERIAL AND METHODS: We examined the expression of PDGF family genes in the developing cochlear tissue of rats using microarrays and tested their role in the proliferation of progenitor hair cells using cellular and molecular biology techniques. RESULTS: It was found that the genes for PDGF-A, PDGF receptor (R)-alpha and PDGFR-beta were highly expressed in the rapidly growing otocyst on embryonic Days 12-14 and weakly expressed thereafter. Reverse transcriptase polymerase chain reaction demonstrated the expression of PDGF-C and confirmed the expression of PDGF-A and PDGFR-alpha and -beta in the developing cochlear tissue of rats and the cultured progenitor hair cells. Inhibition of the expression of PDGFs in the cultured progenitor hair cells with antisense oligonucleotides reduced the DNA synthesis. CONCLUSION: PDGFs and their receptors may play a role in the proliferation of developing cochlear hair cells.