Retinol binding protein 4 induces mitochondrial dysfunction and vascular oxidative damage

Area of Science:

• Cardiovascular Science
• Mitochondrial Biology
• Oxidative Stress Research

Background:

• Mitochondrial dysfunction is a known factor in cardiovascular diseases.
• Elevated serum retinol binding protein 4 (RBP4) is linked to cardiovascular disease.
• The specific role of RBP4 in mitochondrial oxidative stress and vascular damage remains unclear.

Purpose of the Study:

• To investigate the impact of RBP4 on mitochondrial reactive oxygen species (ROS).
• To determine RBP4's effect on mitochondrial dynamics in cardiovascular pathogenesis.
• To elucidate RBP4's role in vascular oxidative damage.

Main Methods:

• Human aortic endothelial cells (HAECs) were treated with RBP4.
• Mitochondrial superoxide generation, content, integrity, and membrane potential were assessed.
• Protein expression related to mitochondrial fusion/fission, apoptosis, and signaling pathways was analyzed.
• RBP4-transgenic (RBP4-Tg) mice were compared to wild-type C57BL/6J mice.

Main Results:

• RBP4 increased mitochondrial superoxide generation and induced dysfunction in HAECs.
• RBP4 altered mitochondrial dynamics by suppressing Mfn-1 and enhancing Drp1/Fis1 expression.
• RBP4 induced endothelial apoptosis, altered Bcl-2 family protein expression, and suppressed PI3K/Akt signaling.
• RBP4-Tg mice showed significant mitochondrial dysfunction and aortic oxidative damage.

Conclusions:

• Retinol binding protein 4 (RBP4) directly contributes to vascular oxidative damage.
• RBP4 accelerates atherosclerosis development through mitochondrial dysfunction.
• This study uncovers a novel mechanism linking RBP4 to cardiovascular pathogenesis.