Arginine-directed glycation and decreased HDL plasma concentration and functionality

Area of Science:

• Biochemistry
• Cardiovascular Research
• Metabolic Disease

Background:

• Low high-density lipoprotein cholesterol (HDL-C) is a risk factor for cardiovascular disease (CVD).
• Impaired anti-atherogenic properties of HDL are linked to increased CVD risk.
• The role of glucose intolerance in HDL modification is unclear.

Purpose of the Study:

• Quantify HDL modification by methylglyoxal and dicarbonyls in healthy individuals and type 2 diabetes patients.
• Characterize the structural, functional, and physiological consequences of HDL modification.
• Predict the impact of HDL modification on high CVD risk groups.

Main Methods:

• Isolated HDL2 and HDL3 fractions from healthy subjects and type 2 diabetes patients.
• Quantified HDL modification by methylglyoxal and related dicarbonyl metabolites.
• Assessed molecular, functional, and physiological characteristics of in vitro glycated HDL.
• Developed a one-compartment model for HDL plasma clearance.

Main Results:

• Methylglyoxal-modified HDL increased from 2.6% to 4.5% in type 2 diabetes mellitus (T2DM) patients.
• Methylglyoxal modification restructured HDL particles, decreasing stability and in vivo plasma half-life.
• Kinetic modeling predicted and clinical data validated a negative correlation between plasma HDL-C and methylglyoxal-modified HDL.

Conclusions:

• Methylglyoxal modification of HDL accelerates its degradation and impairs its functionality.
• This modification likely contributes to increased CVD risk, particularly in high-risk populations.
• Understanding HDL modification is crucial for managing CVD risk in metabolic diseases.