Ryanodine receptor 1 mediates Ca2+ transport and influences the biomechanical properties in RBCs

• Published in: Journal of biomechanics 2009-12, Vol.42 (16), p.2774-2779
• Main Authors: Wang, Xianwei, Chen, Xi, Tang, Zhiyu, Yao, Weijuan, Liu, Xiao, Wei, Risheng, Wang, Xifu, Ka, Weibo, Sun, Dagong, He, Dongqi, Wen, Zongyao, Chien, Shu
• Format: Article
• Language: English
• Subjects: Animals; Calcium - metabolism; Calcium Signaling - physiology; Cells, Cultured; Elastic Modulus - physiology; Erythrocyte Membrane - physiology; Erythrocytes - physiology; Membrane Fluidity - physiology; Physical Medicine and Rehabilitation; Rabbits; Ryanodine Receptor Calcium Release Channel - physiology; Stress, Mechanical; Viscosity
• ISSN: 0021-9290; 1873-2380
• DOI: 10.1016/j.jbiomech.2009.07.036

Abstract Ryanodine receptors (RyRs) are a family of Ca2+ channel proteins that mediate the massive release of Ca2+ from the endoplasmic reticulum into the cytoplasma. In the present study, we manipulated the incorporation of RyR1 into RBC membrane and investigated its influences on the intracellular Ca2+ ([Ca2+ ]in ) level and the biomechanical properties in RBCs. The incorporation of RyR1 into RBC membranes was demonstrated by both immunofluorescent staining and the change of [Ca2+ ]in of RBCs. In the presence of RyR1, [Ca2+ ]in showed biphasic changes, i.e., it increased with the extracellular Ca2+ ([Ca2+ ]ex ) up to 5 μM and then decreased with the further increase of [Ca2+ ]ex . However, [Ca2+ ]in remained constant in the absence of the RyR1. The results of biomechanical measurements on RBCs, including deformability, osmotic fragility, and membrane microviscosity, reflected similar biphasic changes of [Ca2+ ]in mediated by RyR1 with the increases of [Ca2+ ]ex . Therefore, it is believed that RyR1 can incorporate into RBC membrane in vitro, and mediate Ca2+ influx, and then regulate RBC biomechanical properties. This information suggests that RBCs may serve as a model to study the function of RyR1 as a Ca2+ release channel.