Résumé
Objective Toanalyzethealterationsofplasmaglucocerebrosidase(GBA),protein phosphatase 2A (PP2A)and its degradation product ceramide in patients with ischemic stroke. Methods Atotalof45inpatientswithischemicstrokeattheDepartmentofNeurology,theAffiliated Hospital of Logistics College of the CAPF were enrolled from May to September 2013,and 45 age-and sex-matched healthy subjects at the Physical Examination Center collected at the same time period were used as a control group. Blood samples of the patients and healthy subjects were obtained,anticoagulated, and the plasma was separated. H50 protein chip and laser matrix-assisted laser desorption/ionization top of flymassspectrometrywereusedtotestthelevelsofplasmaceramide.Results TheplasmaGBAand PP2A activities in patients with ischemic stroke were significantly lower than those of the control group;the GBA activities of the ischemic stroke group and the control group were 2 . 4 ± 0 . 8 and 3 . 1 ± 1 . 4 U/L respectively. There was significant difference (P<0. 05);the PP2A activities of the two groups were 6. 5 ± 2. 8 and 14. 5 ± 4. 7 U/L respectively (P<0. 01). The relative level of the plasma ceramide in patients with ischemic stroke was 1. 9 ± 0. 7,and it was significantly lower than 12. 2 ± 5. 0 of the control group (P<0.01).Conclusion ThedecreasedlevelsofplasmaGBAandPP2Aactivitiesaswellasthe ceramide in patients with ischemic stroke suggested that the abnormal phosphorylation of synuclein in the blood of patients with stroke.
Résumé
Multiple ecto-phosphoproteins of the goat cauda-epididymal intact spermatozoa have been shown to undergo dephosphorylation in vitro by endogenous phosphoprotein phosphatase(s) located on the sperm outer surface. The major ecto-phosphoproteins that are dephosphorylated have molecular masses of 27, 40, 70, 116 and 205 kDa. The cell surface dephosphorylation reaction is not dependent on bivalent metal ions. Mg2+ (5 mM), Mn2+ (5 mM), orthovanadate (200 μΜ) and cAMP (5 μΜ) have no effect on this surface reaction whereas it is inhibited nearly 50% by Co2+ or Zn2+ (1 mM). Spermidine (5 mM), or Ca2+ (1mM) inhibited to a small extent (approx. 25%) the cell surface dephosphorylation of proteins.