Interleukin-6 induced activation of a non-selective outward cation conductance in human cardiac fibroblasts.

Background: It has been demonstrated that cardiac fibroblasts of the human heart have several myocyte-like features, induced by inflammation.

Objectives: This study analyzed the changes of the expressed currents in the basal condition and in the presence of interleukin-6 in cultured human cardiac fibroblasts.

Methods: Human cardiac fibroblasts were cultured as monolayers from earlier passages (2-4). Whole-cell voltage clamp experiments were performed on single culture human cardiac fibroblasts.

Results: The cultured human cardiac fibroblasts had a membrane resistance of R of 412±91MΩ, and a resting membrane potential of -68.1±3.2mV. Among different cells, we have been analyzed these at which depolarizing clamp steps induced outward currents that reached peak within approx. 20ms and then slowly decayed. Gd decreased the current amplitudes at depolarizing steps. Superfusion with interleukin-6 caused increasing of the outward membrane currents. The changes in the membrane currents continued up to 6min of interleukin-6 perfusion, by reaching their maximum at 3min and slowly decreasing to the level of control recordings at 6min. In the presence of 8μmol/l Gd, interleukin-6 does not modify the membrane currents.

Conclusion: The involvement of mechano sensitive channels in interleukin-6 induced electrical property of fibroblast was proposed. This report presents one particular model of action of interleukin-6, that can open new insights for a deeper understanding of the relationships between interleukin-6 and different ion channels into the fibroblast.