Mitochondrial DNA Promotes NLRP3 Inflammasome Activation and Contributes to Endothelial Dysfunction and Inflammation...

Area of Science:

• Vascular Biology
• Immunology
• Metabolic Diseases

Background:

• NLRP3 inflammasome activation, triggered by mitochondrial DNA (mDNA), drives inflammatory responses.
• Circulating mDNA is associated with diabetic vascular complications, but its role in endothelial dysfunction is unclear.
• This study investigates mDNA's contribution to diabetes-associated endothelial dysfunction and vascular inflammation via NLRP3 activation.

Purpose of the Study:

• To determine if mDNA contributes to diabetes-associated endothelial dysfunction and vascular inflammation through NLRP3 activation.
• To elucidate the mechanisms by which mDNA activates the NLRP3 inflammasome in endothelial cells.
• To assess the therapeutic potential of NLRP3 inhibition in preventing diabetes-related vascular damage.

Main Methods:

• Assessed vascular reactivity, reactive oxygen species (ROS) generation, calcium (Ca2+) influx, and caspase-1/IL-1β activation in mouse mesenteric arteries.
• Utilized normoglycemic, streptozotocin-induced diabetic, and NLRP3 knockout mice.
• Stimulated endothelial cells and arteries with control (cmDNA) and diabetic (dmDNA) mDNA.

Main Results:

• Diabetes impaired endothelium-dependent vasodilation and increased vascular ROS, caspase-1, and IL-1β in wild-type mice, but not in NLRP3 knockout mice.
• Diabetic mDNA (dmDNA) reduced vasodilation and activated NLRP3 in endothelial cells via mitochondrial ROS and Ca2+ influx.
• Patients with type 1 diabetes showed elevated circulating mDNA and caspase-1/IL-1β activation.

Conclusions:

• Diabetic mDNA activates the endothelial NLRP3 inflammasome through Ca2+ influx and mitochondrial ROS.
• NLRP3 deficiency mitigates diabetes-associated vascular inflammation and endothelial dysfunction.
• Targeting the NLRP3 inflammasome is a promising strategy for managing diabetic vascular complications.