Expression of platelet‐derived growth factor (PDGF) and PDGF receptor genes in the developing rat brain

Abstract

Steady-state levels of rat central nervous system (CNS) platelet-derived growth factor (PDGF) A- and B-chain mRNAs were measured by a polymerase chain reaction method employing a synthetic gene internal standard, and the rates of transcription of PDGF A- and B-chain genes in CNS were estimated by a nuclear runoff assay. The abundance of PDGF B-chain mRNA was an order of magnitude below that of PDGF A-chain mRNA, while the rate of PDGF B-chain transcription was only slightly below that for the PDGF A-chain gene, indicating that the half-life of PDGF B-chain in CNS is shorter than that of PDGF A-chain mRNA. No developmental alterations in expression of the PDGF A- and B-chain genes were detected. By contrast, Northern blots showed that steady-state levels of mRNAs encoding the two PDGF receptor proteins, alpha and beta, were markedly higher in embryonic day 15 and postnatal day 6 rat brains than in later life. These results suggest that the actions of PDGF on the brain in vivo are regulated not at the level of PDGF A and B-chain gene expression, but rather by changes in the level of expression of PDGF alpha- and beta-receptor genes.

PDGF-β Receptor Expression in the Dorsocaudal Brainstem Parallels Hypoxic Ventilatory Depression in the Developing Rat

“…Furthermore, in transgenic mice in which the chloramphenicol acetyltransferase gene was placed under transcriptional control of the PDGF-B chain promoter, preferential expression occurred in the cortex, hippocampus, and brainstem, and was highest around birth, suggesting that PDGF-B is developmentally regulated (33). Similar results showing increased PDGF-␤ receptor expression in the neonatal rat brain were reported by Smits and colleagues (34), while the expression of PDGF-␣ receptors increases throughout E15 to P14 and then decreases with advancing age (35,36). Our current findings are in close agreement with previous studies, and extend such observations to the dorsocaudal brainstem, a brain region that plays a major role in the ventilatory response to hypoxia.…”

Inducible expression of neuronal glutamate receptor channels in the NT2 human cell line.

“…Total RNA was isolated (24). The PCR amplification protocol was similar to that of Reddy and Pleasure (25). The PCR primers used were 5' primer, 5'-AACCTGCAGAACCGCAAG-3', and 3' primer, 5'-GCTT-GATGAGCAGGTCTATGC-3'.…”

“…Approximately 300 ng of each isolated band was sequenced with 3.2 pmol of the 5' primer using a Taq DyeDeoxy terminator cycle sequencing kit (Applied Biosystems). The cycle sequencing reactions were performed in a Perkin-Elmer 9600 thermal cycler for 25 cycles with a profile of 96°C for 15 s, 50°C for 1 s, and 60°C for 4 min. Following separation of the extension products on a Select-D G-50 column (5 Prime 3 Prime, West Chester, PA), the reaction mixtures were dried, resuspended in 4 ml of 5:1 formamide/50 mM EDTA, loaded on a 6% sequencing gel, and analyzed using an Applied Biosystems 373 fluorescent sequencer.…”

From Neural Stem Cells to Myelinating Oligodendrocytes

“…Several relevant factors are expressed at the appropriate time in the developing brain: PDGF and its receptor are detected in E14 brain (Reddy and Pleasure, 1992;Sasahara et al, 1992), FGF2 expression increases from E15 to E18 before gliogenesis occurs (Giordano et al, 1992) and BMPs are detected in SVZ during gliogenesis. The density of receptors on NSCs can dictate their sensitivity to certain extrinsic clues (reviewed by Edlund and Jessell, 1999).…”