Increased circulating microparticles in streptozotocin-induced diabetes propagate inflammation contributing to...

Area of Science:

• Cardiovascular Biology
• Endocrinology
• Cell Biology

Background:

• Circulating microparticles (MPs) are elevated in cardiovascular diseases and implicated in disease prognosis.
• Current understanding of MP functions is largely based on in vitro studies, leaving their in vivo impact on vascular inflammation unclear.

Purpose of the Study:

• Investigate the biogenesis, profile, and functional roles of circulating MPs in a diabetic rat model.
• Elucidate the mechanisms by which disease-induced MPs contribute to vascular inflammation and dysfunction.

Main Methods:

• Utilized a streptozotocin-induced diabetic rat model.
• Employed single microvessel perfusion and systemic cross-transfusion techniques.
• Analyzed MP characteristics, including origin, aggregation, and phosphatidylserine exposure.

Main Results:

• Diabetic rats exhibited a >130-fold increase in circulating MPs compared to normal rats.
• Diabetic MPs, originating from platelets, leukocytes, and endothelial cells, showed increased externalized phosphatidylserine and circulated as aggregates.
• Perfusion or transfusion of diabetic MPs induced endothelial adhesion, leukocyte recruitment, and augmented microvessel permeability in normal rats, mimicking diabetic vascular changes.

Conclusions:

• Elevated circulating MPs in diabetes actively promote vascular inflammation and dysfunction.
• Externalized phosphatidylserine on MPs is crucial for their interaction with endothelium and leukocytes.
• These findings provide mechanistic insights into MP-mediated pathogenesis of diabetes-associated microvascular complications.