Format

Send to

Choose Destination
Br J Haematol. 2010 Feb;148(4):611-22. doi: 10.1111/j.1365-2141.2009.07993.x. Epub 2009 Dec 1.

Pathogenesis of the erythroid failure in Diamond Blackfan anaemia.

Author information

1
Whitehead Institute for Biomedical Research, Cambridge, MA, USA. colin.sieff@childrens.harvard.edu

Abstract

Diamond Blackfan anaemia (DBA) is a severe congenital failure of erythropoiesis. Despite mutations in one of several ribosome protein genes, including RPS19, the cause of the erythroid specificity is still a mystery. We hypothesized that, because the chromatin of late erythroid cells becomes condensed and transcriptionally inactive prior to enucleation, the rapidly proliferating immature cells require very high ribosome synthetic rates. RNA biogenesis was measured in primary mouse fetal liver erythroid progenitor cells; during the first 24 h, cell number increased three to fourfold while, remarkably, RNA content increased sixfold, suggesting an accumulation of an excess of ribosomes during early erythropoiesis. Retrovirus infected siRNA RPS19 knockdown cells showed reduced proliferation but normal differentiation, and cell cycle analysis showed a G1/S phase delay. p53 protein was increased in the knockdown cells, and the mRNA level for p21, a transcriptional target of p53, was increased. Furthermore, we show that RPS19 knockdown decreased MYB protein, and Kit mRNA was reduced, as was the amount of cell surface KIT protein. Thus, in this small hairpin RNA murine model of DBA, RPS19 insufficient erythroid cells may proliferate poorly because of p53-mediated cell cycle arrest, and also because of decreased expression of the key erythroid signalling protein KIT.

PMID:
19958353
PMCID:
PMC2866500
DOI:
10.1111/j.1365-2141.2009.07993.x
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Wiley Icon for PubMed Central
Loading ...
Support Center