Effect of High-Density Lipoprotein from Healthy Subjects and Chronic Kidney Disease Patients on the CD14 Expression...

Area of Science:

• Biochemistry
• Immunology
• Nephrology

Background:

• Uremic patients exhibit altered high-density lipoprotein (HDL) with lost anti-inflammatory properties, contributing to cardiovascular disease risk.
• Chronic kidney disease (CKD) is associated with impaired polymorphonuclear leukocyte (PMNL) function, exacerbating inflammation.

Purpose of the Study:

• To investigate the impact of HDL from CKD and hemodialysis (HD) patients on CD14 expression on PMNLs.
• To explore the role of HDL in modulating PMNL inflammatory markers in kidney disease.

Main Methods:

• HDL isolation via one-step density gradient centrifugation.
• PMNL isolation using discontinuous Ficoll-Hypaque density gradient centrifugation.
• Quantification of CD14 surface expression by flow cytometry and Rac1 activity by activation pull-down assay.

Main Results:

• HDL significantly increased CD14 surface expression on PMNLs, with a more pronounced effect from HDL of uremic patients.
• Serum amyloid A (SAA) increased CD14 expression independently, but not when part of an HDL particle.
• Lipid raft disruption reduced CD14 expression, and HDL from HD patients, unlike healthy subjects, did not decrease Rac1 activity.

Conclusions:

• HDL from CKD and HD patients demonstrably increases CD14 expression on PMNLs, suggesting a pro-inflammatory role in kidney disease.
• The observed increase in CD14 expression by HDL, even from healthy individuals, warrants further investigation into its pathophysiological relevance.