Colchicine Modulates the Actin Cytoskeleton by Direct Binding to the Monomer and Facilitating Polymerization

Area of Science:

• Biochemistry
• Cell Biology
• Pharmacology

Background:

• Actin cytoskeleton dynamics are crucial for cellular functions.
• Colchicine is an anti-inflammatory drug with an incompletely understood mechanism of action.
• Microtubule inhibition is the primary known effect of colchicine.

Purpose of the Study:

• To investigate the direct effects of colchicine on actin cytoskeleton dynamics.
• To determine if colchicine modulates actin polymerization and stability.
• To elucidate the molecular interactions between colchicine and actin.

Main Methods:

• In vitro biochemical and biophysical assays.
• Cellular studies using human monocytic and murine B-lymphoma cell lines.
• Thermal shift assays and molecular docking.

Main Results:

• Colchicine binds directly to G-actin with submicromolar affinity.
• Colchicine enhances actin polymerization and stabilizes F-actin.
• Cellular treatment increased the F-/G-actin ratio, cortical actin organization, and altered cell mechanics.

Conclusions:

• Colchicine possesses a previously unrecognized ability to modulate actin dynamics.
• Findings provide mechanistic insight into colchicine's anti-inflammatory effects.
• Suggests potential therapeutic applications in actin-related diseases.