A series of artificial membranes called small unilaminar vesicles (SUVs) comprising different molar ratios of phosphatidylcholine (PC)/cholesterol (Ch) were constructed and exogenous PC and Ch were transferred into hu...A series of artificial membranes called small unilaminar vesicles (SUVs) comprising different molar ratios of phosphatidylcholine (PC)/cholesterol (Ch) were constructed and exogenous PC and Ch were transferred into human peripheral blood lymphocytes through incubating the cells with SUVs in order to study the effects of the changed constituents of membrane lipids on the expression of CD 71 in lymphocytes, the binding characteristics of CD 71 molecules with its ligand and its internalization. It was found that after the treatment of SUVs, the Ch content in the plasmic membrane was increased with a decrease of PC/Ch ratio. After incubation with ConA for 48 h,the percentage of CD 71-positive lymphocytes increased with the increase of the availab1e binding sites for CD 71 to its ligand, but the affinity of CD 71 with its ligand was lowered- When Ch synthesis was blocked with HMG-CoAreductase inhibitor (Lovastatin), the number of CD71 molecules was obviously reducce but the afinity of CD 71with its ligand elevated- It is believed that that the construction of the lipid environment can directly affect the properties of CD 71 molecules. Less fluid phase of the lipid environment might be suitable to the move;nent of CD 71 in the membrane but minimize the tendency for CD 71 to maintain a con formation of high affinity state.展开更多
Highly purified CD71 protein was isolated from human placental trophoblasts and Molt-4 cells with affinity chromatography and was shown with SDS-PAGE as an obvious protein band of 90 ×103u under reducing conditio...Highly purified CD71 protein was isolated from human placental trophoblasts and Molt-4 cells with affinity chromatography and was shown with SDS-PAGE as an obvious protein band of 90 ×103u under reducing condition and about 180 × 103u under non-reducing condition. The protein molecules were reconstituted into artificial membranes composed of different ratios of phospholipids (PL)/cholesterol (Ch). Circular dichroism analysis demonstrated that there was a decrease of the beta-laminar structure and an increase of alpha-helica and random coils when the Ch content of the artificial membranes DMPC/Ch or DOPC/Ch was increased. Tryptophan fluorescence spectrum also demonstrated that along with the changes of the lipid constituents of the artificial membrane,the spatial conformation of CD71 protein underwent corresponding changes.展开更多
Objective： To detect the expression of glial fibrillary acid protein （GFAP） and taurine transporter （TauT） in the retinal Müller cells in high glucose culture with taurine and to explore the influence of glu...Objective： To detect the expression of glial fibrillary acid protein （GFAP） and taurine transporter （TauT） in the retinal Müller cells in high glucose culture with taurine and to explore the influence of glucose on the taurine transporting, and the possible protective effects of taurine on MUller cells in early diabetic retinopathy. Methods： The Müller cells from the rat retina were cultured in high glucose, and GFAP and Taut expressions were detected in the cells treated with different doses of taurine by immuocytochemical fluorescein staining and Western blotting. Results： High glucose enhanced the expression of GFAP and decreased the expression of TauT in Müller cells. Taurine decreased the up-regulation of GFAP in the cells which was induced by high glucose; 0. 1-10 mmol/L taurine increased the expression of TauT in Müller cells. Conclusion： Taurine can inhibit the changes in Müller cell resulted from high glucose.展开更多
HL-60 cells were synchronized from G1 to S phase boundary with a double thymidine block. Samples of the cells were collected at scheduled time points after the release of the block. It was found with immunoblot analys...HL-60 cells were synchronized from G1 to S phase boundary with a double thymidine block. Samples of the cells were collected at scheduled time points after the release of the block. It was found with immunoblot analysis that the protein expression of cyclin E and D, fluctuated periodically. They both began to increase in G, phase,reached the peak in S phase and declined gradually in G, phase. The protein expression of cyclin-dependent kinase P34cdk2 showed no periodical changes- The antiproliferation effect of retinoic acid or arotinoidethylester on HL-60cells was manifested by a block in Go/G1 of most of the cells and resulted in a marked decrease of the protein expression of cyclin E and D1 and no significant change of P34cdk2. These findings suggest that retinoic acid or arotinoidethylester is able to suppress the proliferation of HL-cells or to induce their differentiation.展开更多
文摘A series of artificial membranes called small unilaminar vesicles (SUVs) comprising different molar ratios of phosphatidylcholine (PC)/cholesterol (Ch) were constructed and exogenous PC and Ch were transferred into human peripheral blood lymphocytes through incubating the cells with SUVs in order to study the effects of the changed constituents of membrane lipids on the expression of CD 71 in lymphocytes, the binding characteristics of CD 71 molecules with its ligand and its internalization. It was found that after the treatment of SUVs, the Ch content in the plasmic membrane was increased with a decrease of PC/Ch ratio. After incubation with ConA for 48 h,the percentage of CD 71-positive lymphocytes increased with the increase of the availab1e binding sites for CD 71 to its ligand, but the affinity of CD 71 with its ligand was lowered- When Ch synthesis was blocked with HMG-CoAreductase inhibitor (Lovastatin), the number of CD71 molecules was obviously reducce but the afinity of CD 71with its ligand elevated- It is believed that that the construction of the lipid environment can directly affect the properties of CD 71 molecules. Less fluid phase of the lipid environment might be suitable to the move;nent of CD 71 in the membrane but minimize the tendency for CD 71 to maintain a con formation of high affinity state.
文摘Highly purified CD71 protein was isolated from human placental trophoblasts and Molt-4 cells with affinity chromatography and was shown with SDS-PAGE as an obvious protein band of 90 ×103u under reducing condition and about 180 × 103u under non-reducing condition. The protein molecules were reconstituted into artificial membranes composed of different ratios of phospholipids (PL)/cholesterol (Ch). Circular dichroism analysis demonstrated that there was a decrease of the beta-laminar structure and an increase of alpha-helica and random coils when the Ch content of the artificial membranes DMPC/Ch or DOPC/Ch was increased. Tryptophan fluorescence spectrum also demonstrated that along with the changes of the lipid constituents of the artificial membrane,the spatial conformation of CD71 protein underwent corresponding changes.
基金Supported by the National Natural Science Foundation of China(No. 30571570)
文摘Objective： To detect the expression of glial fibrillary acid protein （GFAP） and taurine transporter （TauT） in the retinal Müller cells in high glucose culture with taurine and to explore the influence of glucose on the taurine transporting, and the possible protective effects of taurine on MUller cells in early diabetic retinopathy. Methods： The Müller cells from the rat retina were cultured in high glucose, and GFAP and Taut expressions were detected in the cells treated with different doses of taurine by immuocytochemical fluorescein staining and Western blotting. Results： High glucose enhanced the expression of GFAP and decreased the expression of TauT in Müller cells. Taurine decreased the up-regulation of GFAP in the cells which was induced by high glucose; 0. 1-10 mmol/L taurine increased the expression of TauT in Müller cells. Conclusion： Taurine can inhibit the changes in Müller cell resulted from high glucose.
文摘HL-60 cells were synchronized from G1 to S phase boundary with a double thymidine block. Samples of the cells were collected at scheduled time points after the release of the block. It was found with immunoblot analysis that the protein expression of cyclin E and D, fluctuated periodically. They both began to increase in G, phase,reached the peak in S phase and declined gradually in G, phase. The protein expression of cyclin-dependent kinase P34cdk2 showed no periodical changes- The antiproliferation effect of retinoic acid or arotinoidethylester on HL-60cells was manifested by a block in Go/G1 of most of the cells and resulted in a marked decrease of the protein expression of cyclin E and D1 and no significant change of P34cdk2. These findings suggest that retinoic acid or arotinoidethylester is able to suppress the proliferation of HL-cells or to induce their differentiation.
