High density lipoprotein-associated sphingosine 1-phosphate promotes endothelial barrier function

Area of Science:

• Vascular Biology
• Lipid Metabolism
• Cell Signaling

Background:

• High density lipoproteins (HDL) are key carriers of sphingosine 1-phosphate (S1P) in plasma.
• Endothelial barrier integrity is crucial for vascular health and function.

Purpose of the Study:

• To investigate the role of HDL and its component S1P in regulating endothelial barrier function.
• To elucidate the signaling pathways involved in HDL-mediated endothelial cell responses.

Main Methods:

• Electric cell substrate impedance sensing to measure endothelial barrier integrity.
• Inhibition studies using pertussis toxin and S1P receptor antagonists.
• Western blotting to assess Erk1/2 and Akt activation.
• Cell motility assays.

Main Results:

• HDL significantly increased endothelial barrier integrity and cell motility.
• These effects were dependent on S1P signaling via S1P1 receptors.
• HDL stimulated Erk1/2 and Akt activation, with Akt playing a more dominant role.
• Pertussis toxin and S1P1 antagonists inhibited HDL-induced signaling and functional effects.

Conclusions:

• HDL promotes endothelial barrier integrity and motility through its S1P component.
• The S1P1/Akt signaling pathway is critical for HDL-mediated endothelial cell responses.
• HDL represents a potential therapeutic target for enhancing vascular barrier function.