Potent suppression of vascular smooth muscle cell migration and human neointimal hyperplasia by KV1.3 channel blockers

Area of Science:

• Cardiovascular Biology
• Molecular Pharmacology
• Vascular Biology

Background:

• Neointimal hyperplasia is a significant cause of vascular graft failure.
• Vascular smooth muscle cell proliferation and migration are key drivers of neointimal hyperplasia.
• Potassium channels play a role in regulating vascular smooth muscle cell function.

Purpose of the Study:

• To investigate the role of K(V)1 potassium channels in neointimal hyperplasia.
• To evaluate the potential of K(V)1 channel blockers as therapeutic agents for inhibiting neointimal hyperplasia.

Main Methods:

• Vascular smooth muscle cells from human and mouse blood vessels were cultured.
• Gene expression was analyzed using RT-PCR and immunocytochemistry.
• Channel function was assessed via patch-clamp electrophysiology, calcium imaging, and cell migration assays.
• Organ culture models were used to test the efficacy of K(V)1.3 blockers in inhibiting neointimal hyperplasia.

Main Results:

• K(V)1.3 channels were uniquely upregulated in proliferating vascular smooth muscle cells and neointimal formations.
• K(V)1.3 channel blockers inhibited voltage-dependent potassium currents and calcium entry in proliferating cells.
• Three K(V)1.3 blockers significantly reduced vascular smooth muscle cell migration, with margatoxin showing high potency (IC50 = 85 pM).
• Two blockers effectively inhibited neointimal hyperplasia in organ-cultured human vein samples.

Conclusions:

• K(V)1.3 potassium channels are actively involved in vascular smooth muscle cell proliferation and migration.
• Blockade of K(V)1.3 channels presents a promising therapeutic strategy for inhibiting neointimal hyperplasia.
• K(V)1.3 channel blockers may also be beneficial in treating other vascular remodeling conditions.