Mesenchymal stem cells transmigrate over the endothelial barrier

Area of Science:

• Cardiovascular Research
• Regenerative Medicine
• Cell Biology

Background:

• Mesenchymal stem cells (MSCs) show therapeutic potential for heart failure.
• Successful cell therapy requires MSCs to cross the endothelial barrier, particularly in intracoronary applications.
• The transmigration mechanism of MSCs across endothelium is not well understood.

Purpose of the Study:

• To investigate the ability of MSCs to transmigrate across an endothelial barrier.
• To analyze the direct interactions between MSCs and endothelial cells during transmigration.
• To determine the time course of MSC transmigration for potential clinical applications.

Main Methods:

• Co-culture experiments of MSCs on endothelial monolayers.
• Isolated heart perfusions using gold-labeled MSCs.
• Electron microscopy and confocal laser scanning microscopy to visualize MSCs and endothelial cell interactions.

Main Results:

• MSCs exhibited a flattened morphology and integrated into the endothelial monolayer.
• Electron microscopy revealed direct cell-cell contacts and abolished tight junctions between endothelial cells.
• Confocal microscopy showed significant MSC transmigration: 30% within 30 min, 50% within 60 min, and 53% by 120 min.

Conclusions:

• MSCs possess the capability for transendothelial migration.
• The majority of MSCs migrate within the first 30 minutes, which is a critical finding for optimizing clinical exposure times.
• This study provides essential insights into MSC behavior for developing effective cardiac cell therapies.