Altered mitochondrial dynamics contributes to endothelial dysfunction in diabetes mellitus.

Area of Science:

• Vascular Biology
• Mitochondrial Biology
• Diabetic Complications

Background:

• Endothelial dysfunction is a key factor in atherosclerosis development in diabetes mellitus.
• Mechanisms underlying endothelial dysfunction in diabetes remain unclear.
• Altered mitochondrial dynamics, including increased fission and reactive oxygen species (ROS) production, are implicated in diabetes.

Purpose of the Study:

• To investigate the role of altered mitochondrial dynamics in endothelial dysfunction in diabetes mellitus.
• To determine if increased mitochondrial fission contributes to endothelial dysfunction in diabetic states.

Main Methods:

• Compared mitochondrial morphology and fission protein expression (Fis1, Drp1) in endothelial cells from diabetic patients and healthy controls.
• Exposed human aortic endothelial cells to high glucose (30 mmol/L) to mimic diabetic conditions.
• Utilized small interfering RNA (siRNA) to silence Fis1 and Drp1 expression.
• Assessed mitochondrial ROS production, endothelial nitric oxide synthase (eNOS) activation, and cyclic guanosine monophosphate (cGMP) production.

Main Results:

• Diabetic endothelial cells exhibited mitochondrial fragmentation and increased Fis1 expression.
• High glucose exposure induced mitochondrial fission, increased Fis1 and Drp1 expression, elevated ROS production, and impaired eNOS/cGMP signaling.
• Silencing Fis1 or Drp1 ameliorated high glucose-induced mitochondrial and endothelial dysfunction.
• ROS scavenger provided no additional benefit, suggesting mitochondrial ROS mediate the dysfunction.

Conclusions:

• Increased mitochondrial fission is a significant contributor to endothelial dysfunction in diabetic conditions.
• Targeting mitochondrial fission may offer a therapeutic strategy for diabetic vascular complications.