| Title: | Hypoxia Activates a Ca-Permeable Cation Conductance Sensitive to Carbon Monoxide and to GsMTx-4 in Human and Mouse Sickle Erythrocytes |
| Author: |
Trudel, Marie; Sachs, Frederick; Gottlieb, Philip A.; Vandorpe, David Henry; Xu, Chang; Shmukler, Boris E.; Otterbein, Leo E.; Brugnara, Carlo; Alper, Seth Leo
Note: Order does not necessarily reflect citation order of authors. |
| Citation: | Vandorpe, David H., Chang Xu, Boris E. Shmukler, Leo E. Otterbein, Marie Trudel, Frederick Sachs, Philip A. Gottlieb, Carlo Brugnara, and Seth L. Alper. 2010. Hypoxia activates a Ca2+-permeable cation conductance sensitive to carbon monoxide and to GsMTx-4 in human and mouse sickle erythrocytes. PLoS ONE 5(1): e8732. |
| Full Text & Related Files: |
2806905.pdf (958.2Kb; PDF)
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| Abstract: | Background: Deoxygenation of sickle erythrocytes activates a cation permeability of unknown molecular identity (Psickle), leading to elevated intracellular [Ca2+] ([Ca2+]i) and subsequent activation of KCa 3.1. The resulting erythrocyte volume decrease elevates intracellular hemoglobin S (HbSS) concentration, accelerates deoxygenation-induced HbSS polymerization, and increases the likelihood of cell sickling. Deoxygenation-induced currents sharing some properties of Psickle have been recorded from sickle erythrocytes in whole cell configuration. Methodology/Principal Findings: We now show by cell-attached and nystatin-permeabilized patch clamp recording from sickle erythrocytes of mouse and human that deoxygenation reversibly activates a Ca2+- and cation-permeable conductance sensitive to inhibition by Grammastola spatulata mechanotoxin-4 (GsMTx-4; 1 µM), dipyridamole (100 µM), DIDS (100 µM), and carbon monoxide (25 ppm pretreatment). Deoxygenation also elevates sickle erythrocyte [Ca2+]i, in a manner similarly inhibited by GsMTx-4 and by carbon monoxide. Normal human and mouse erythrocytes do not exhibit these responses to deoxygenation. Deoxygenation-induced elevation of [Ca2+]i in mouse sickle erythrocytes did not require KCa3.1 activity. Conclusions/Significance: The electrophysiological and fluorimetric data provide compelling evidence in sickle erythrocytes of mouse and human for a deoxygenation-induced, reversible, Ca2+-permeable cation conductance blocked by inhibition of HbSS polymerization and by an inhibitor of strctch-activated cation channels. This cation permeability pathway is likely an important source of intracellular Ca2+ for pathologic activation of KCa3.1 in sickle erythrocytes. Blockade of this pathway represents a novel therapeutic approach for treatment of sickle disease. |
| Published Version: | doi:10.1371/journal.pone.0008732 |
| Other Sources: | http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2806905/pdf/ |
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| Citable link to this page: | http://nrs.harvard.edu/urn-3:HUL.InstRepos:4874791 |
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