Deoxygenation-induced cation conductance (Psickle)

The sickle-induced non-selective cation leak pathway, commonly known as Psickle, is a deoxygenation-induced membrane conductance characteristic of red blood cells (RBCs) in sickle cell disease (SCD) [1, 3]. Upon deoxygenation and the subsequent polymerization of hemoglobin S (HbS), the RBC membrane becomes permeable to cations, allowing the influx of calcium (Ca2+) and sodium (Na+) and the efflux of potassium (K+) [1, 6]. This ion flux leads to cellular dehydration, which increases the intracellular concentration of HbS and further promotes polymerization and sickling, creating a pathophysiological cycle of cell damage [3, 8]. While its exact molecular identity has been a subject of research, recent evidence identifies the mechanosensitive ion channel PIEZO1 as a primary component, with additional contributions from N-methyl-D-aspartate (NMDA) receptors and potentially other channels like TRPC6 or Aquaporin-1 [3, 4, 10]. Pharmacological targeting of this pathway, such as through NMDA receptor antagonists like memantine or PIEZO1 inhibitors, aims to prevent the calcium-induced activation of the Gárdos channel and the resulting dehydration, offering a therapeutic strategy to improve RBC survival and reduce vaso-occlusive complications in SCD patients [4, 5, 6].

Other names

Sickle-induced non-selective cation leak pathwayPsickle pathwayDeoxygenation-induced cation leakSickle cell cation leakSickle-induced cation conductance

Inhibition of the non-selective cation conductance to prevent calcium influx and subsequent activation of the Gárdos channel, thereby reducing red blood cell dehydration and sickling.