Protein synthesis inhibition significantly reduces proplatelet formation. Mature, primary murine megakaryocytes were cultured for 24 hours in the IncuCyte system. (A) Representative images of 10-hour time point, ×20 original magnification. (B-D) Rate and extent of proplatelet production were measured in ImageJ. Cells ≥330 µm2 were categorized as (1) round-megakaryocytes (circularity ≥0.4) or (2) proplatelet-producing megakaryocytes (circularity <0.4), and objects were normalized to initial (day 4) object counts and expressed as percentage of proplatelet-producing megakaryocytes. MKs were cultured with (B) puromycin (250 μg/mL, final), (C) cycloheximide (50 μg/mL, final), or (D) chloramphenicol (250 μg/mL, final); n = 3 biological replicates. The scale bar represents 50 um. **P < .005; ****P < .0001.
