Regulatory Role of Mitochondria in the Shedding of Platelet Membrane Protein GPIbα

Abstract

To investigate the role of mitochonaria in the regulation of platelet membrane protein GPIbα shedding and its mechanisms. The washed platelets were obtained from peripheral blood in healthy volunteers and co-incubated with mitochondrial inhibitor carbonyl cyanide m-chlorophenyl hydrazone (CCCP), mitochondrial protector cyclosporin A (CsA) or matrix metalloproteinases inhibitor GM6001. After the platelets was stimulated, the effect of mitochondria to the shedding in platelet membrane protein GPIbα was detected by flow cytometry. Depolarization of mitochondrial membrane potential and the respiratory function of mitochondrial could be induced and destroyed by the uncoupling agent CCCP. At the same time, the shedding of GPIbα was detected out, and the result showed a statistical significance, which showed that the shedding of GPIbα could be activated by the damaged of mitochondrial in platelets. After the mitochondrial was protected by CsA, the shedding of GPIbα was inhibited significantly. GM6001 could only inhibited the shedding of GPIbα, but showed no inhibitation to the function of mitochondrial, which showed that the shedding of GPIbα was regulated at the mitochondrial, and the regulatory enzyme of receptor shedding (ADAM17) was located in the pathway of downstream of mitochondria. After the oxidative damage in cells was inhibited by NAC, and the changes of GPIbα shedding was detected, the result showed that the GPIbα shedding could be inhibited by NAC, which showed a dose-dependent manner. The GPIbα shedding could be caused by abnormality function of metabolic, and the metabolic imbalance of ROS is caused by the abnormallity function of mitochondria.