Macrophage-colony-stimulating factor (CSF-1) modulates a differentiation-specific inward-rectifying potassium current in human leukemic (HL-60) cells
✍ Scribed by Steven J. Wieland; Robin H. Chou; Qi-Hua Gong
- Publisher
- John Wiley and Sons
- Year
- 1990
- Tongue
- English
- Weight
- 849 KB
- Volume
- 142
- Category
- Article
- ISSN
- 0021-9541
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✦ Synopsis
I9 102 A voltage-activated inward-rectifying K + conductance (IK,) appears in human promyelocytic leukemia (HL-60) cells during phorbol ester-induced differentiation into macrophages. This conductance was detected in the cells 24 hours after exposure to phorbol-12-myristate-13-acetate (PMA), as the cells began to express the macrophage phenotype, and continued to increase for 4 days after PMA exposure. The magnitude of inward current was a function of external K'; current was blocked by extracellular or intracellular Cs+ and by extracellular Eaf +.
Hyperpolarization produced activation at membrane potentials more negative than -80 mV, and a slower, partial inactivation also occurred at potentials more negative than -100 mV. This conductance was not detected in proliferating cells nor in granulocytes derived from HL-60 cells which were induced to differentiate with retinoic acid (RA). Exposure of differentiated macrophages to recombinant human CSF-1 produced inhibition of the IK, beginning within 1 minute after exposure. CSF-1 inhibition of IK, channels in cell-attached patches indicated that channel modulation was via intracellular mediators. The rapid inhibition of the inward rectifier by the macrophage-specific CSF-1 appears to be one of the earliest cellular responses to this factor.