Erythrocyte Deformability Correlates to Intracellular Calcium Level

  • Authors: S. Huang, J. Han
  • Sponsorship: RLE at MIT

Elevated intracellular calcium level ([Ca++]i) and reduced deformability  in red blood cells (RBCs) are commonly associated with blood-related diseases[1][2][3] as well as in-vivo ageing[4]. The correlation between RBC deformability and [Ca++]i has been established at the bulk level, typically accompanied with changes in ATP level and RBC size[4]. It is, however, unclear whether changes in RBC deformability would correspond to [Ca++]i at the single-RBC level.

In this project, we attempt to establish the connection between single RBC deformability and [Ca++]i using a microfluidic device as described[5]. Calcium ionophore A23187 was used for calcium loading, creating different levels of [Ca++]i. RBC deformability is assessed by measuring the microcirculatory velocity of RBCs in a microfluidic device with narrow gaps[5]. Simultaneous measurement of calcium intensity and transit velocity was performed while an individual RBC traversed the microchannels.

Figure 1. Snapshot of experimental video analyzed Matlab program. Real time flow (left top corner, F) and calcium intensity are tracked simultaneously. Single RBCs transit velocity is then plotted against calcium intensity (right)

  1. Chien S (1987) Red cell deformability and its relevance to blood flow. Ann. Rev. Physiol. 49:177-192. [↩]
  2. Baskurt OK, et al. (1998) Red Blood Cell Deformability in Sepsis. American Journal of Respiratory and Critical Care Medicine 157(2):421-427. [↩]
  3. Dondorp AM, Pongponratn E, & White NJ (2004) Reduced microcirculatory flow in severe falciparum malaria: pathophysiology and electron-microscopic pathology. Acta Tropica 89(3):309-317. [↩]
  4. Shiga T, Sekiya M, Maeda N, Kon K, & Okazaki M (1985) Cell age-dependent changes in deformability and calcium accumulation of human erythrocytes. Biochimica et Biophysica Acta (BBA) – Biomembranes 814(2):289-299. [↩] [↩]
  5. Bow H, et al. (2011) A microfabricated deformability-based flow cytometer with application to malaria. Lab on a Chip 11(6):1065-1073. [↩] [↩]

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