CLASP1 regulates endothelial cell branching morphology and directed migration

Area of Science:

• Cell Biology
• Biophysics
• Biomaterials Science

Background:

• Endothelial cell (EC) branching is crucial for vascular development and relies on microtubule (MT) cytoskeleton dynamics.
• Extracellular matrix (ECM) mechanosensing is a known regulator of cytoskeletal organization, but its specific role in targeting intracellular signaling for EC branching is unclear.

Purpose of the Study:

• To investigate how ECM composition and density influence MT growth dynamics in ECs.
• To determine the role of cytoplasmic linker associated protein 1 (CLASP1) in mediating ECM-induced MT reorganization for EC branching morphogenesis.

Main Methods:

• High-resolution fluorescent microscopy to visualize MT dynamics.
• Computational image analysis to quantify MT growth parameters.
• Experiments utilizing varying ECM substrates (glass, collagen-I, fibronectin) with different densities.

Main Results:

• CLASP1 promotes slow MT growth on glass ECMs and short-lived MT growth on high-density collagen-I and fibronectin ECMs.
• High-density collagen-I and fibronectin ECMs reduce MT growth speeds in EC branches.
• CLASP1-mediated MT dynamics promote short, branched protrusions essential for directed EC migration.

Conclusions:

• ECM properties significantly modulate MT growth dynamics in ECs through CLASP1.
• Targeting CLASP1-dependent MT dynamics offers a mechanism for controlling EC migration and vascular morphogenesis.