Intermediate Conductance Calcium-Activated Potassium Channel Activation in Stem Cell Antigen-1 Positive Cells Contributed to Vascular Restenosis.

BACKGROUND: Vascular restenosis, a common complication following vascular reconstruction, results in stenosis or blockage that impairs vascular remodeling. This process is driven by the activation of vascular stem cells. Growing evidence suggests that intermediate conductance calcium-activated potassium (IKCa) channels play a crucial role in regulating the function of these cells. This study aims to explore how IKCa channels influence Sca-1+ (stem cell antigen-1 positive) stem cells in the context of vascular anastomotic restenosis.

METHODS: To investigate the role and mechanism of the IKCa channel in Sca-1+ cell activation and its involvement in vascular anastomosis restenosis, we assessed the impact of IKCa channel deficiency on the vascular restenosis-promoting ability of Sca-1+ cells using a mouse femoral artery anastomosis model. Mechanistic insights were gained through patch-clamp electrophysiology, intracellular Ca2+ measurement, and molecular biology techniques.

RESULTS: Genetic deletion of IKCa channels in IKCa-/- mice led to reduced neointimal formation and decreased proliferation of Sca-1+ cells at the anastomotic site. In vitro studies confirmed the presence of functional IKCa channels in Sca-1+ cells and demonstrated that IKCa and TRPC1 (transient receptor potential canonical 1) channels cooperate in regulating membrane potential and intracellular Ca2+ levels. Furthermore, our findings suggest that IKCa channel-mediated modulation of ERK (extracellular signal-regulated kinase) and p38 phosphorylation underpins a key signaling mechanism in this process.

CONCLUSIONS: This study clarifies the role of the IKCa-TRPC1-Ca2+ pathway in activating vascular Sca-1+ cells and establishes the contribution of the IKCa channel to vascular restenosis development. Understanding how IKCa channels affect the function of vascular Sca-1+ cells provides valuable insights into the complex mechanisms of vascular remodeling during vascular stenosis.