Endothelial IGFBP6 suppresses vascular inflammation and atherosclerosis

Area of Science:

• Cardiovascular Biology
• Molecular Medicine
• Atherosclerosis Research

Background:

• Inflammation is a key driver of atherosclerosis, alongside dyslipidemia.
• Intrinsic factors protecting against vascular inflammation are limited.
• Endothelial dysfunction contributes significantly to atherosclerotic plaque development.

Purpose of the Study:

• To identify novel intrinsic factors that counteract endothelial inflammation and atherosclerosis.
• To investigate the role of insulin-like growth factor binding protein 6 (IGFBP6) in vascular homeostasis.
• To elucidate the molecular mechanisms underlying IGFBP6's anti-inflammatory actions.

Main Methods:

• Analysis of IGFBP6 expression in human atherosclerotic tissues and patient serum.
• In vitro studies using human endothelial cells with siRNA-mediated IGFBP6 reduction and overexpression.
• In vivo studies utilizing IGFBP6-deficient and endothelial-cell-specific IGFBP6-overexpressing mouse models.
• Investigation of the MVP-JNK/NF-κB signaling pathway.

Main Results:

• IGFBP6 levels are decreased in human atherosclerotic arteries and serum.
• IGFBP6 reduction in endothelial cells enhances inflammatory molecule expression and monocyte adhesion.
• IGFBP6 overexpression reverses pro-inflammatory effects induced by disturbed flow (DF) and tumor necrosis factor (TNF).
• IGFBP6 acts via the MVP-JNK/NF-κB signaling axis.
• IGFBP6 deficiency exacerbates atherosclerosis in mice, while overexpression confers protection.

Conclusions:

• Reduced endothelial IGFBP6 is a predisposing factor for vascular inflammation and atherosclerosis.
• IGFBP6 functions as a crucial homeostasis-associated molecule restraining endothelial inflammation.
• Targeting endothelial IGFBP6 presents a potential therapeutic strategy for atherosclerosis.