Rice Endosperm Protein Improves the Anti-Inflammatory Effects of High-Density Lipoprotein and Produces Lower Atherosclerotic Lesion Accelerated by the Renal Mass Reduction than Casein in a Mouse Model

Abstract It has been shown that apolipoprotein A-V (apoA-V) over-expression significantly lowers plasma triglyceride levels and decreases atherosclerotic lesion development. To assess the feasibility of recombinant high density lipoprotein (rHDL) reconstituted with apoA-V and apolipoprotein A-I (apoA-I) as a therapeutic agent for hyperlipidemic disorder and atherosclerosis, a series of rHDL were synthesized in vitro with various mass ratios of recombinant apoA-I and apoA-V. It is interesting to find that apoA-V of rHDL had no effect on lipoprotein lipase (LPL) activation in vitro and very low density lipoprotein (VLDL) clearance in HepG2 cells and in vivo. By contrast, LPL activation and VLDL clearance were inhibited by the addition of apoA-V to rHDL. Furthermore, the apoA-V of rHDL could not redistribute from rHDL to VLDL after incubation at 37°C for 30 min. These findings suggest that an increase of apoA-V in rHDL could not play a role in VLDL clearance in vitro and in vivo, which could, at least in part, attribute to the lost redistribution of apoA-V from rHDL to VLDL and LPL binding ability of apoA-V in rHDL. The therapeutic application of rHDL reconstituted with apoA-V and apoA-I might need the construction of rHDL from which apoA-V could freely redistribute to VLDL.

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Anti-Inflammatory Effects of HDL (High-Density Lipoprotein) in Macrophages Predominate Over Proinflammatory Effects in Atherosclerotic Plaques

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/atvbaha.119.313253 ◽

2019 ◽

Vol 39 (12) ◽

Cited By ~ 17

Author(s):

Panagiotis Fotakis ◽

Vishal Kothari ◽

David G. Thomas ◽

Marit Westerterp ◽

Matthew M. Molusky ◽

...

Keyword(s):

Gene Expression ◽

High Density Lipoprotein ◽

Density Lipoprotein ◽

High Density ◽

Mitogen Activated Protein Kinase ◽

Endoplasmic Reticulum Stress Response ◽

Cholesterol Depletion ◽

Inflammatory Gene Expression ◽

Inflammatory Gene ◽

Anti Inflammatory

Objective: HDL (high-density lipoprotein) infusion reduces atherosclerosis in animal models and is being evaluated as a treatment in humans. Studies have shown either anti- or proinflammatory effects of HDL in macrophages, and there is no consensus on the underlying mechanisms. Here, we interrogate the effects of HDL on inflammatory gene expression in macrophages. Approach and Results: We cultured bone marrow–derived macrophages, treated them with reconstituted HDL or HDL isolated from APOA1 Tg ;Ldlr −/− mice, and challenged them with lipopolysaccharide. Transcriptional profiling showed that HDL exerts a broad anti-inflammatory effect on lipopolysaccharide-induced genes and proinflammatory effect in a subset of genes enriched for chemokines. Cholesterol removal by POPC (1-palmitoyl-2-oleoyl-glycero-3-phosphocholine) liposomes or β-methylcyclodextrin mimicked both pro- and anti-inflammatory effects of HDL, whereas cholesterol loading by POPC/cholesterol-liposomes or acetylated LDL (low-density lipoprotein) before HDL attenuated these effects, indicating that these responses are mediated by cholesterol efflux. While early anti-inflammatory effects reflect reduced TLR (Toll-like receptor) 4 levels, late anti-inflammatory effects are due to reduced IFN (interferon) receptor signaling. Proinflammatory effects occur late and represent a modified endoplasmic reticulum stress response, mediated by IRE1a (inositol-requiring enzyme 1a)/ASK1 (apoptosis signal-regulating kinase 1)/p38 MAPK (p38 mitogen-activated protein kinase) signaling, that occurs under conditions of extreme cholesterol depletion. To investigate the effects of HDL on inflammatory gene expression in myeloid cells in atherosclerotic lesions, we injected reconstituted HDL into Apoe −/− or Ldlr −/− mice fed a Western-type diet. Reconstituted HDL infusions produced anti-inflammatory effects in lesion macrophages without any evidence of proinflammatory effects. Conclusions: Reconstituted HDL infusions in hypercholesterolemic atherosclerotic mice produced anti-inflammatory effects in lesion macrophages suggesting a beneficial therapeutic effect of HDL in vivo.

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