Membrane Remodelling and Vesicle Formation During Ageing of Human Red Blood Cells

Abstract

Background/Aims: A high surface-to-volume ratio and a spectrin membrane-skeleton (MS) confer to the mammalian red blood cells (RBCs) their characteristic deformability, mechanical strength and structural stability. During their 120 days of circulatory life in humans, RBCs decrease in size, while remaining biconcave disks, owing to a coordinated decrease in membrane surface area and cell water. It is generally believed that part of the membrane is lost with the shedding of spectrin-free vesicles of the same type that can be obtained in vitro by different treatments. If this were true, an excess of MS would arise in old RBCs, with respect to the lipid bilayer. Aim of this paper was to investigate this aspect. Methods: Quantification of spectrin by electrophoretic methods was carried out in RBCs of different age. Results: Spectrin decreases, on a per cell basis, with RBC ageing. On the other hand, the membrane raft protein marker flotillin-2, while decreasing in the membrane of old cells, was found to be strongly depleted in the membrane of in vitro-induced vesicles. Conclusion: Part of the membrane-skeleton is probably lost together with part of the lipid bilayer in a balanced way. These findings point to a mechanism for the in vivo release of membrane that is different from that which is known to occur in vitro.

Effect of Red Raisins (Vitis Vinifera L.) Intake on the Level of Some Hematological Tests in a Group of Female Volunteers

“…Also, MCV levels showed up mild increment at five subjects after taking Raisins and the increment percentages were 3.2%, 0,8%, 2.7%, 6.4% and 1.7% respectively as it appears in Table 2 and Figure 6, this is may be related to the fact that 20 day are not sufficient to have a satisfactory results regarding MCV level and we need a bit longer duration. also it is may be explained by the length of RBC life span which takes approximately 120 day [53]. Iron deficiency anaemia is one of the most common of the non-communicable disease which needs urgent effective corrective measures.…”

Membrane Rearrangements in the Maturation of Circulating Human Reticulocytes

“…The series of maturational processes that RBCs and Retics undergo in vivo cannot be studied by analyzing the material that is lost in the circulation, because this is cleared before it could be recovered from plasma (Ciana et al, 2017a). Therefore, the only hints could be obtained from the comparison of the membrane at the beginning and end of the process, be this the maturation of R2 Retics to RBCs or the aging of the circulating RBCs, with all the inaccuracy and lack of sensitivity associated with the quantification of differences between large numbers.…”

“…Flotillins and stomatin are highly enriched in membrane rafts (de Gassart et al, 2003;Ciana et al, 2014). We have previously observed that especially flotillin-2 is lost in a disproportionate manner with respect to the loss of membrane surface area that takes place during the physiological aging of RBCs, suggesting an involvement of membrane rafts also in this physiological age-related remodeling of the RBC membrane (Ciana et al, 2017a). We therefore wondered whether membrane rafts are also in some way selected for removal from the membrane of R2 Retics.…”

Atomic force microscopy and Raman spectra profile of blood components associated with exposure to cigarette smoking

“…This indicates that nano-vesicles formation and its shedding can be related with diminish RBC size, as previously reported. 55 Cigarette induced changes in structure by nanovesicles formation and diminish RBC size that could be considered as an accelerated ageing cells process and inducing a lost of RBC deformability. [45][46][47][48]…”