An RNA interference model of RPS19 deficiency in Diamond Blackfan Anemia recapitulates defective hematopoiesis and rescue by dexamethasone: identification of dexamethasone responsive genes by microarray

No citation available. Published: 2005.06.14

Benjamin L. Ebert, Michele M. Lee, Jennifer L. Pretz, Aravind Subramanian, Raymond Mak, Todd R. Golub, Colin A. Sieff

Abstract

Diamond Blackfan Anemia (DBA), a congenital erythroblastopenia, is a model disease for the study of erythroid differentiation, but is poorly understood. RPS19 is the only gene yet to have been associated with DBA, but its relevance to erythroid differentiation is unclear. The molecular basis for the stimulation of erythropoiesis by glucocorticoids in patients with DBA has not been identified. We demonstrate that targeted degradation of the RPS19 gene, through retroviral expression of short hairpin RNAs (shRNAs), in cultured human CD34+ cells blocks the proliferation and differentiation of erythroid progenitor cells. Treatment of RPS19 deficient cells with dexamethasone restores erythroid differentiation to normal levels. We investigated the molecular basis of pharmacologic therapies for DBA using oligonucleotide microarrays to survey gene expression in CD34+ cells treated with combinations of dexamethasone, erythropoietin, stem cell factor, and interleukin-3. Dexamethasone did not alter expression of RPS19, but activated a genetic program that includes a set of key hematopoietic regulatory genes. Genes specific to erythroid progenitor cells were up-regulated by dexamethasone, while genes specific to non-erythroid lineages were down-regulated. Deficiency of RPS19 therefore blocks proliferation of immature erythroid progenitor cells, and dexamethasone activates proliferation of the same cell population through mechanisms independent of RPS19.

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Supplemental Data

Description Link/Filename
Manuscript Ebert, RPS19 and dex in DBA, Blood 2005.pdf
Commentary in Blood RPS19 paper commentary, Blood 2005.pdf
Gene expression data: CEL files DBA_cel_files.zip
Supplementary Figure S1 Figure S1.pdf
Supplementary Table S1 TableS1.xls
Supplementary Table S2 TableS2.xls
Supplementary Table S3 TableS3.xls
Supplementary Table S4 TableS4.xls
Supplementary Table S5 TableS5.xls