Erythrocyte membrane proteins and membrane skeleton

Considerable advances in the research field of erythrocyte membrane were achieved in the recent two decades.New findings in the structure-function correlation and interactions of erythrocyte membrane proteins have attracted extensive attention.Interesting progress was also made in the molecular pathogenesis of erythrocyte membrane disorders.Advances in the composition,function and interac-tion of erythrocyte membrane proteins,erythrocyte mem-brane skeleton,and relevant diseases are briefly described and summarized here on the basis of domestic and world literatures.

Facile discovery of red blood cell deformation and compromised membrane/skeleton assembly in Prader—Willi syndrome

Prader—Willi syndrome(PWS)is a rare congenital disease with genetic alterations in chromosome 15.Although genetic disorders and DNA methylation abnormalities involved in PWS have been investigated to a significant degree,other anomalies such as those in erythrocytes may occur and these have not been clearly elucidated.In the present study,we uncovered slight anemia in children with PWS that was associated with increased red blood cell(RBC)distribution width(RDW)and contrarily reduced hematocrit(HCT)values.Intriguingly,the increased ratio in RDW to HCT allowed sufficient differentiation between the PWS patients from the healthy controls and,importantly,with individuals exhibiting conventional obesity.Further morphologic examinations revealed a significant deformity in erythrocytes and mild hemolysis in PWS patients.Comprehensive mechanistic investigations unveiled compromised membrane skeletal assembly and membrane lipid composition,and revealed a reduced F-actin/G-actin ratio in PWS patients.We ascribed these phenotypic changes in erythrocytes to the observed genetic defects,including DNA methylation abnormalities.Our collective data allowed us to uncover RBC deformation in children with PWS,and this may constitute an auxiliary indicator of PWS in early childhood.

Erythrocyte membrane protein abnormalities in β-thalassemia of the Li nationality in Hainan

Objective To determine the composition of abnormal red cell membrane skeletin. Methods By sodium dodecyl sulphate polyacrylamide gel electrophoresis of ghostcorpuscles, we quantified the amount of protein by densitometric evaluation.Results The results showed that in β-thalassernia, the amount of spectrin, 4.5 protein and globin significantly increased compared with the controls (26.05 + 1.46, 21.69 + 1.86; 22.87 + 5.61, 12.99 +2.33; 15.23+3.31 and 4.97+2.73, respectively, P＜0.05).Conclusion These data suggest that the erythrocyte membrane protein composition matched with globin in patients with β-thalassemia of the racial Li minority are different from the normal control. These factors increase rigidity but decrease deformability of the β-thalassemic red cell membrane, which may lead to hemolytic anemia.

Biodegradable composite polymer as advanced gel electrolyte for quasi-solid-state lithium-metal battery

The development of low-cost and eco-friendly gel polymer electrolytes (GPEs) with a wide window, ideal compatibility, and structural stability is an effective measure to achieve safe high-energy-density lithium-metal batteries. Herein, a biodegradable composite polyacrylonitrile/poly-L-lactic acid nanofiber membrane (PAL) is synthesized and used as a robust skeleton for GPEs. The 3D nanofiber membrane (PAL-3-C12) prepared with an adjusted weight ratio of polyacrylonitrile (PAN)/poly-L-lactic acid (PLLA) and spinning solution concentration delivers decent thermal stability, biodegradability, and liquid electrolyte absorbability. The “passivation effect” of PAN upon lithium metal is effectively alleviated by hydrogen bonds formed in the PAL chains. These advantages enable PAL GPEs to work stably to 5.17 ​V while maintaining high ionic conductivity as well as excellent corrosion resistance and dielectric properties. The interfacial compatibility of optimized GPEs promotes the stable operation of a Li||PAL-3-C12 GPEs||Li symmetric battery for 1000 ​h at 0.15 ​mA ​cm^(−2)/0.15 ​mA ​h cm^(−2), and the LiFePO4 full cell retains capacity retention of 97.63% after 140 cycles at 1C.