OBJECTIVE@#To investigate the effect of enhanced
autophagy in
megakaryocyte to proplatelet formation in
children with
immune thrombocytopenia(
ITP).@*
METHODS@#Giemsa
staining and
immunofluorescence staining were used to observe
megakaryocyte morphology and proplatelet formation,
Western blot was used to determine the expression of
cytoskeleton protein and
autophagy related protein. Autophagr
regulation drugs Rap or 3-MA was used to regulate
autophagy of
megakaryocytes.@*RESULTS@#Some
vacuole-like structures was found in
ITP megakaryocytes of the
children, the expression of LC3II/I (
ITP 1.32±0.18; Ctrl 0.49±0.16,P<0.05) and Atg5-Atg12 (
ITP 0.69±0.17; Ctrl 0.12±0.08,P<0.05) was significantly higher in
ITP children as compared with those in
control group. The immu- nofluorescence
staining showed that the
cytoskeleton arrangement in
megakaryocytes of
ITP children was abnormal, and the
phosphorylation of
myosin light chain was also increased(
ITP 0.74±0.09, Ctrl 0.05±0.02,P<0.05).
In vitro, inducer or inhibitor of
autophagy could regulate the
production of proplatelet and the expression of
cell cycle related
protein, including CyclinD1(Veh 1.08±0.12; Rap 0.46±0.04; Rap+3-MA 0.70±0.03), CyclinD2(Veh 0.47±0.04; Rap 0.27±0.04; Rap+3-MA 0.41±0.03), P21(Veh 0.15±0.01; Rap 0.04±0.01; Rap+3-MA 0.05±0.01).@*CONCLUSION@#Enhanced
autophagy is the key factor of poor proplatelet formation in
megakaryocytes of
ITP children.