Project description:We employed a gene complementation strategy combined with microarray screening to identify miRNAs involved in the formation of erythroid (red blood) cells. To search for GATA-1-regulated erythroid miRNAs, we used the Gata-1– erythroblast line G1E. These cells proliferate in culture as immature erythroid precursors and undergo terminal maturation when GATA-1 activity is restored. G1E-ER4 is a sub-line stably expressing an estrogen-activated form of GATA-1 (GATA-1 fused to the ligand binding domain of the estrogen receptor). Treatment of G1E-ER4 cells with estradiol induces a GATA-1-regulated program of gene expression with concomitant cellular maturation. We used a microarray to evaluate the expression of 292 different miRNAs in G1E-ER4 cells at 0 versus 24 hours after GATA-1 activation. Affymetrix gene expression profiling has previously been deposited (GEO accession no. GSE628). Keywords: microRNA analysis of a cell-line model of erythroid maturation
Project description:Analysis of erythroid differentiation using Gata1 gene-disrupted G1E ER4 clone cells. Estradiol addition activates an ectopically expressed Gata-1-estrogen receptor fusion protein, triggering synchronous differentiation. 30 hour time course corresponds roughly to late burst-forming unit-erythroid stage (t=0 hrs) through orthochromatic erythroblast stage (t=30 hrs). Experiment Overall Design: G1E ER4 cells cultured in G1E medium were treated at 6 time points with estradiol to initiate erythroid differentiation by activating Gata1 transcription factor and total RNAs from treated cells were extracted for microarray experiment. The erythroid differentiation status was confirmed by cell pellet color and expression of microRNA miR451. The design was similar to an earlier studies (Welch, J. J., Watts, J. A., Vakoc, C. R., Yao, Y., Wang, H., Hardison, R. C., Blobel, G. A., Chodosh, L. A., and Weiss, M. J. (2004)). Global regulation of erythroid gene expression by transcription factor GATA-1. Blood 104, 3136-3147), except that a more recent version of Affymetric chip was used to acheive greater transcriptome coverage.