Lipidomics reveals multiple pathway effects of a multi-components preparation on lipid biochemistry in ApoE*3Leiden.CETP mice

Abstract

Background: Causes and consequences of the complex changes in lipids occurring in the metabolic syndrome are only partly understood. Several interconnected processes are deteriorating, which implies that multi-target approaches might be more successful than strategies based on a limited number of surrogate markers. Preparations from Chinese Medicine (CM) systems have been handed down with documented clinical features similar as metabolic syndrome, which might help developing new intervention for metabolic syndrome. The progress in systems biology and specific animal models created possibilities to assess the effects of such preparations. Here we report the plasma and liver lipidomics results of the intervention effects of a preparation SUB885C in apolipoprotein E3 Leiden cholesteryl ester transfer protein (ApoE*3Leiden.CETP) mice. SUB885C was developed according to the principles of CM for treatment of metabolic syndrome. The cannabinoid receptor type 1 blocker rimonabant was included as a general control for the evaluation of weight and metabolic responses.

Methodology/principal findings: ApoE*3Leiden.CETP mice with mild hypercholesterolemia were divided into SUB885C-, rimonabant- and non-treated control groups. SUB885C caused no weight loss, but significantly reduced plasma cholesterol (-49%, p<0.001), CETP levels (-31%, p<0.001), CETP activity (-74%, p<0.001) and increased HDL-C (39%, p<0.05). It influenced lipidomics classes of cholesterol esters and triglycerides the most. Rimonabant induced a weight loss (-9%, p<0.05), but only a moderate improvement of lipid profiles. In vitro, SUB885C extract caused adipolysis stimulation and adipogenesis inhibition in 3T3-L1 cells.

Conclusions: SUB885C, a multi-components preparation, is able to produce anti-atherogenic changes in lipids of the ApoE*3Leiden.CETP mice, which are comparable to those obtained with compounds belonging to known drugs (e.g. rimonabant, atorvastatin, niacin). This study successfully illustrated the power of lipidomics in unraveling intervention effects and to help finding new targets or ingredients for lifestyle-related metabolic abnormality.

Figure 1. Food intake and body weight.

(A) Food intake (per cage) and (B) body weight (per mouse) were recorded and measured at day 0, 2, 3, 4, 9, 11, 14, 21 and 28 for SUB885C-treated mice and control (*p<0.05 vs. control).

Figure 2. Plasma lipid, CETP and lipoprotein.

Plasma concentrations are shown for TC, TG, HDL-C, CETP level and activity (A) of the SUB885C-, rimonabant- and non-treated mice at week 4 (concentrations in the control group are set to be 100% and relative changes of treated groups were illustrated in % compared with the control, *p<0.05, ** p<0.01, *** p<0.001). Alterations of Cho (B), TG (C) and phospholipids (D) in the pooled lipoprotein profiles of the SUB885C- and non-treated mice at week 4. Fractions 4–7 as VLDL; 8–9 as IDL; 10–15 as LDL and 16–23 as HDL.

Figure 3. Lipidomics of plasma and liver reveals differences between non-treated and SUB885C-treated mice.

Principle component analyses (PCA) of plasma and liver lipidomics datasets were applied to differentiate the non-treated controls (n = 7) and the SUB885C treated mice (n = 8). PCA biplots for (A) plasma samples and (B) liver samples.

Figure 4. Adipolytic and adipogenic activities of SUB885C in 3T3-L1 adipocytes.

(A) Glycerol release as the result of adipolysis in 3T3-L1 adipocytes after incubation with SUB885C (500× and 2500× diluted) and 20 µM isoproterenol dissolved in DMSO with 1% as final concentration. (B) Inhibition of adipose conversion in differentiating 3T3-L1 adipocytes by SUB885C. (C) Morphological analysis of the differentiated 3T3-L1 adipocytes. The cells were treated with 20 µg/ml DAPI (top row), which stained the nuclei of the cells and gave an indication of cell numbers. The phase contrast of the microscope showed the outlines of the cells (bottom row) and gave an overview of cell density and morphology. The magnification is on the left.

Figure 5. The summary of SUB885C effects.

The effects of SUB885C were illustrated both in vitro and in ApoE*3Leiden.CETP mice with biochemical and lipidomics measurements. The improvement for insulin sensitivity was result from Wang et al. .