Low-density lipoprotein receptor-related protein 1 (LRP1)-derived peptides protect against aggregation of LDL and cholesterol loading of vascular cells. Molecular and Cellular basis for antiatherosclerotic efficacy

ABSTRACT: LRP1 and, in particular the region that spans the C-terminal half of domain CR9 (from Gly1127 to Cys1140), named LP3, is essential for aggregated LDL internalization and human coronary vascular smooth muscle cells (hcVSMC)-cholesterol loading. Here, we investigated whether LP3 and its retro-enantio version (DP3) are protective against sphingomyelinase (SMase) and phospholipase 2 (PLA2)-induced LDL aggregation, the structural basis underlying this protection and the impact that LRP1-derived peptides might have on hcVSMC-cholesterol loading and cholesterol-modulated signaling pathways. For this purpose, biochemical, biophysical, molecular, proteomic, and cellular experiments were performed. Turbidimetry measurements show that LP3 and DP3 inhibit LDL aggregation induced by SMase and PLA2 in a dose-dependent manner, although the efficacy of DP3 is higher. Gel filtration chromatography (GFC) and transmission electron microscopy (TEM) show that LP3, and more efficiently DP3, almost completely counteract the increased percentage of aggregated LDL induced by both SMase and PLA2, respectively. Native polyacrilamide gradient gel electrophoresis (GGE), agarose gel electrophoresis (AGE) and high-performance thin layer chromatography (HPTLC) partitioning of LDL phospholipids indicated that LP3 and DP3 prevent SMase-induced alterations in LDL size, electric charge and phospholipid content but not those induced by PLA2. In contrast, LP3 and DP3 show high efficacy to counteract changes in ApoB-100 conformation induced by both SMase and PLA2. Together, these results indicate that LRP1-derived peptides protect LDL against aggregation induced by SMase and PLA2 through a common mechanism based on their capacity to prevent ApoB-100 conformational changes. Proteomics and computational modeling methods suggest that LRP1 derived peptides are able to establish strong electrostatic interactions with a specific ApoB-100 basic region. TLC and confocal microscopy show that DP3 with higher efficacy than LP3 significantly reduce intracellular cholesteryl ester accumulation induced by SMase-LDL in hcVSMC. Moreover, proteomics studies evidence several signaling pathways modulated by SMase-LDL that are counteracted specifically by DP3. These findings demonstrate that LRP1 derivative peptides protect against LDL aggregation and preserve vascular cells against cholesterol loading and associated alterations in critical signal pathways

ORGANISM(S): Homo Sapiens

SUBMITTER: Eduard Sabidó  

PROVIDER: PXD011261 | panorama | Sat Jan 23 00:00:00 GMT 2021

REPOSITORIES: PanoramaPublic