Besides modulation of reverse cholesterol transport, high density lipoprotein (HDL) is able to modulate vascular function by stimulating endothelial nitric oxide synthase. Recently, it could be documented that this function of HDL was significantly impaired in patients with chronic heart failure (CHF). We investigated alterations in the HDL proteome in CHF patients. Therefore, HDL was isolated from 5 controls (HDL_healthy) and 5 CHF patients of NYHA-class IIIb (HDL_CHF). Proteome analysis of HDL particles was performed by two-dimensional liquid chromatography–mass spectrometry (SCX/RP LC–MS/MS). In total, we identified 494 distinct proteins, of which 107 proteins were commonly found in both groups (HDL_CHF and HDL_healthy) indicating a high inter-subject variability across HDL particles. Several important proteins (e.g. ITGA2, APBA1 or A2M) varied in level. Functional analysis revealed regulated pathways. A minor proportion of bacteria-derived proteins were also identified in the HDL-particles.

The extension of the list of HDL-associated proteins allows besides their mere description new insights into alterations in HDL function in diseases. In addition, the detection of bacterial proteins bound to HDL will broaden our view of HDL not only as a cholesterol carrier but also as a carrier of proteins.