Interleukin-1β switches electrophysiological states of synovial fibroblasts

• Published in: American journal of physiology. Regulatory, integrative and comparative physiology integrative and comparative physiology, 1997-11, Vol.273 (5), p.R1822-R1828
• Main Authors: Kolomytkin, Oleg V, Marino, Andrew A, Sadasivan, Kalia K, Wolf, Robert E, Albright, James A
• Format: Article
• Language: English
• ISSN: 0363-6119; 1522-1490
• DOI: 10.1152/ajpregu.1997.273.5.r1822

The role of electrophysiological events in signal transduction of interleukin-1β (IL-1β) was investigated in rabbit synovial fibroblasts using the perforated-patch method. Aggregated synovial fibroblasts occurred in two different electrophysiological states having membrane potentials ( V ) of -63 ± 4 ( n = 71) and -27 ± 10 mV ( n = 55) (high and low V , respectively). IL-1β affected the cells with high V ; it switched the state of the cell from high to low V . This effect was strongly dependent on the external potential applied to the cell membrane. Low V (-30 mV) alone without IL-1β did not switch the state of the cells. Thus a synergistic effect involving the cytokine and cell V in switching the electrophysiological state of the cell was shown, indicating that electrophysiological changes are involved in signal transduction. Gap junctions between aggregated cells were necessary for the cells to have a high V and to respond to IL-1β. Gap junction resistance between adjacent cells was estimated as 300 ± 100 MΩ. Our findings suggest that the electrophysiological behavior of synovial fibroblasts is tightly connected to a signaling or intracellular mediator system that is triggered by IL-1β.