Caspase-3 has a nonapoptotic function in erythroid maturation

Carlile GW, Smith DH, Wiedmann M.
Source: Blood
Publication Date: (2004)
Issue: 103(11): 4310-4316
Research Area:
Immunotherapy / Hematology
Cells used in publication:
CD34+ cell, human
Species: human
Tissue Origin: blood
Nucleofectorâ„¢ I/II/2b
Primary CD34+ erythroblast cells derived from human peripheral blood were co-nucleofected with a plasmid expressing GFP and an siRNA construct targeted against caspase-3. Down-regulation of caspase-3 resulted in a reduction of cells that underwent enucleation with no change in the fraction of cells undergoing apoptosis.
Caspase-3 plays a central role in apoptosis. It is also activated in normal erythropoiesis, with its activity peaking early during development (erythroid colony-forming unit [CFU-E] stage). In the present study, we have reduced the expression and subsequent enzymatic activity of caspase-3 by transfection of small interfering RNA (siRNA) directed to caspase-3 in a differentiating human erythroid culture system. We find that siRNA treatment yields a 50% reduction in cells that undergo enucleation with no change in the fraction of cells that undergo apoptosis, measured throughout the culture. Furthermore, a substantial fraction of treated cells are unable to complete the transition from pronormoblasts to basophilic normoblasts. These results demonstrate that caspase-3 is required for efficient erythropoiesis in this model system.