Expresssion of VEGF-A and PlGF.

(A) Expression of VEGF-A and PlGF mRNAs in human mature hematopoietic cells. RT-PCR experiments were performed with the use of total RNA isolated from human erythroblasts, granulocytes, or megakaryocytes. We designed primers in exons 1 and 8 of the VEGF-A gene and in exons 2 and 7 of the PlGF gene in order to amplify the different splice variants. In these conditions, expected PCR products are as follows: 442 base pair (bp) for VEGF-121, 514 bp for VEGF-145, 574 bp for VEGF-165, 646 bp for VEGF-189, and 697 bp for VEGF-206 (lane VEGF-A); 396 bp for PlGF-1, 333 bp for PlGF-2, and 509 bp for PlGF-3 (lane PlGF). As a control, we used amplification of RT products with S14 primers. (B) Expression of VEGF-A and PlGF mRNAs during in vitro erythroid differentiation. Day 1 (corresponding to a majority of CFU-E and late BFU-E progenitors) to day 7 (corresponding to differentiated erythroblasts) are the various times of the second stage of culture. The 2 major VEGF-A transcripts, VEGF-121 (442 bp) and VEGF-165 (574 bp), and the PlGF-1 transcript (333 bp) are shown. As a control, we used amplification of RT products with S14 primers.