Mechanism of erythrocyte phosphatidylserine exposure induced by high concentrated glucose / 中国实验血液学杂志

This study was aimed to investigate the mechanism of phosphatidylserine exposure of human erythrocytes induced by high concentrated glucose. After exposure to high concentrated glucose, the phosphatidylserine (PS) exposure and forward scatter value were analyzed by flow cytometry; the activities of caspase-3 and caspase-8 were detected; The inhibitory effect of leupeptin on cell PS exposure induced by high concentrated glucose was observed by flow cytometry and fluorescent microscopy. The results showed that the high concentrated glucose could induce PS exposure of erythrocytes and this inducing efficiency was dependent on the glucose concentrations. With increase of the glucose concentrations, the percentages of cells with exposed PS also increased. When the glucose concentration was 0.8 mol/L, the PS exposure was over 80%. However, caspase-3 and caspase-8 were not activated during PS exposure of cells induced by high concentrated glucose, but leupeptin could significantly inhibit PS exposure and volume shrinkage induced by high concentrated glucose. With increase of the leupeptin concentrations, the percentage of cells with exposed PS decreased and the cell volume increased. It is concluded that the high concentrated glucose can result in serious PS exposure, which does not depend on caspase. It can be hypothesized that the PS exposure of erythrocytes induced by high concentrated glucose may be controlled by an unknown pathway sensitive to leupeptin.

Inhibitory effect of trehalose on phosphatidylserine exposure, osmotic fragility and membrane lipid peroxidation damage of erythrocytes induced by high concentration of glucose / 中国实验血液学杂志

Though high concentration of glucose can benefit the survival of lyophilized human red blood cells, the high concentration of glucose can result in serious damage of red blood cells. This study was aimed to investigate the inhibitory effect of trehalose on damage of red blood cells induced by high concentration of glucose. After incubation with the high concentration of glucose buffer containing different concentrations of trehalose for three hours at 37 degrees C, the phosphatidylserine exposure and the osmotic fragility of cells were analyzed by flow cytometry and the lipid peroxidation of membrane was evaluated by TBA method. The results showed that the high concentration of glucose could lead to phosphatidylserine exposure, osmotic fragility increase, and lipid peroxidation damage which were dependent on the glucose concentrations and incubation temperature. However, trehalose could effectively prevent the phosphatidylserine exposure, osmotic fragility increase, and lipid peroxidation damage induced by high concentration glucose. With increase of the trehalose concentrations. As the trehalose concentration increases, the phosphatidylserine exposure, maloni-aldehyde concentration and cell debris rate decreased gradually. In conclusion, the high concentration of glucose can lead to phosphatidylserine exposure, osmotic fragility increase, and lipid peroxidation damage of red blood cells. However, trehalose can inhibit the damaging effects of high concentration of glucose on red blood cells, which may be useful for the application of sugars to lyophilization of red blood cells.

Stability of glycosylated platelets under cold storage / 中国实验血液学杂志

This study was aimed to investigate the stability and in vitro function of glycosylated platelets concentrates after long-term refrigeration. The experiments were divided into 4 groups: group preserved at room temperature (RT group), group preserved at 4 degrees C (4T group), group glycosylated and preserved at 4 degrees C (U + 4 group) and group preserved at 4 degrees C and glycosylated (4 + U group). All groups followed for up to 14 days. The binding rate of RCA I lectin and expression of Plt surface markers CD62P, CD42b and Annexin V binding were determined by flow cytometry. pH and mean volume were determined by pH meter and hematotocytometer respectively. Platelet aggregation was detected by aggregometer. The results showed that during storage up to 14 days RCAI binding rate of modified groups was 5 - 6 fold of RT group. The pH of platelets suspension had no significant difference between these two groups (p > 0.05). Mean volumes of both groups (10.6 +/- 1.9 fL and 11.14 +/- 1.1 fL) were also no significant difference (p > 0.05). Furthermore, aggregation responsiveness of modified groups was better than that of RT groups (p < 0.05) although both decreased during the storage. The expression level of CD62P, CD42b and Annexin V binding during 5 days of storage had no significant difference between modified and fresh platelet groups (p > 0.05). While the expression level of CD62P and PS increased and the expression level of CD42b decreased during storage up to 14 days, there was significant difference between modified and fresh platelet groups (p < 0.01). It is concluded that the glycan modification is stable during storage up to 14 days. The glycosylated platelets retain in vitro function better than RT platelets during storage, but it shows activation to varying degrees in vitro after storage for 5 days.

Advances of studies on platelet additive solutions - review / 中国实验血液学杂志

Platelet additive solutions (PAS) can partly or fully substitute blood plasma during platelet storage in normal air temperature. There are some advantages such as avoiding transfusion of large volume of plasma with possible adverse reactions and circulatory overload, saving plasma for other purposes, improving storage conditions, maintaining the viability and haemostatic function of platelet at normal level, and making it easy to inactivate pathogens. There has been an increasing interest in the study of PAS in the past 20 years, the compositions of different PAS have been reported one after another, and the protective effects of PAS on platelets have become better and better. This article focuses on the advances of studies of the composition of PAS, the functions of the different compositions and platelet quality in vitro and in vivo after storage.

Regularity of sugar-uptake in human red blood cells / 中国实验血液学杂志

Lyophilization of human red blood cells has important significance in clinical application. Some sugars, especially trehalose, can be more tolerant of some organism or cells to dry environments, But, how to bring sugars into cells is a challenge. This study was aimed to investigate the regularity of sugar-uptake in human red blood cells. The absorption rate of trehalose and glucose in red blood cells, free hemoglobin level and erythrocyte deformation index were determined at different incubation temperature (4, 25 and 37 degrees C), different sugar concentration (0, 0.2, 0.4, 0.6, 0.8 and 1 mol/L) and different incubation time (1, 3, 5, 7 and 9 hours). The results showed that with increase of temperature and extracellular sugar concentration, the uptake of sugar in red blood cells also increased, the intracellular trehalose and glucose concentrations were over 30 mmol/L and 40 mmol/L respectively. The effects of incubation time on uptake of trehalose and glucose were different. With prolonging of incubation time, the uptake of trehalose showed firstly increase and then decrease, however, the uptake of glucose showed a constant increase. But the loading process had side-effect on free hemoglobin and maximum deformation index (MAXDI) of red blood cells, especially for trehalose, which mainly come from high osmotic pressure. It is concluded that the uptake of sugars in red blood cells is closely dependent on incubation temperature, extracellular sugar concentration and incubation time. In certain condition, the efficiency of sugar uptake is very high, but this process also damages red blood cells so as to affect the application of sugars in lyophilization of red blood cells. The research in the future should focus on how to deal with the relation between cell injury and uptake efficiency of sugar in red blood cells.