Preliminary Investigation about the Expression of G Protein-Coupled Receptors in Platelets from Patients with Chronic Immune Thrombocytopenic Purpura

Preliminary Study on Apoptotic Proteins in Platelet from Adult Patients with Chronic Immune Thrombocytopenic Purpura

BACKGROUND

Adult chronic idiopathic thrombocytopenic purpura (ITP) is a chronic and usually lifelong hemorrhagic disorder in which enhanced platelet destruction and -weakened platelet production lead to thrombocytopenia. In this study, the p38 mitogen-activated protein kinase (p38-MAPK), early growth response 1 (EGR-1), p53, Bcl-xL, Bak, Bax, and reactive oxygen species (ROS) in platelets from adult patients with chronic ITP were investigated.

METHODS

Platelets were isolated from blood samples collected from 20 adult patients with chronic ITP and 20 healthy volunteers. p38-MAPK, EGR-1, p53, Bcl-xL, Bak, Bax, and ROS were determined by flow cytometry, and the results were analyzed by EXPO32 ADC.

RESULTS

Flow cytometry showed the expression levels of p38-MAPK (61.66 ± 19.38% vs. 27.52 ± 14.34%), EGR-1 (62.22 ± 20.48% vs. 9.05 ± 5.79%), p53 (56.82 ± 20.07% vs. 4.35 ± 2.04%), Bak (39.86 ± 11.45% vs. 20.82 ± 11.85%), Bax (36.85 ± 15.99% vs. 6.69 ± 5.01%), and ROS (19.98 ± 1.47% vs. 1.29 ± 0.10%) were all elevated (p < 0.05 compared with healthy volunteers). In addition, pro-survival Bcl-xL (5.38 ± 1.52% vs. 21.20 ± 6.04%) was decreased markedly in platelets from adult patients with chronic ITP (p < 0.05 compared with healthy volunteers).

CONCLUSIONS

Our findings reveal that platelets in adults with chronic ITP display a proapoptotic gene expression phenotype, based on the enhanced expression of p38-MAPK, EGR-1, p53, Bak, Bax, and ROS, and attenuated expression of Bcl-xL, suggesting increased sensitivity toward apoptosis.