High-density lipoprotein inhibits ox-LDL-induced adipokine secretion by upregulating SR-BI expression and suppressing ER Stress pathway

The present study aimed to investigate the role of D4F, an apolipoprotein A-I mimetic peptide, in macrophage apoptosis induced by the glycated high-density lipoprotein (gly-HDL)-induced endoplasmic reticulum (ER) stress C/EBP homologous protein (CHOP) pathway, and unravel the regulatory role of autophagy in this process. Our results revealed that except for suppressing the accumulation of lipids within RAW264.7 macrophages caused by gly-HDL, D4F inhibited gly-HDL-induced decrease in the cell viability and increase in lactate dehydrogenase leakage and cell apoptosis, which were similar to 4-phenylbutyric acid (PBA, an ER stress inhibitor). Besides, similar to PBA, D4F inhibited gly-HDL-induced ER stress response activation evaluated through the decreased PERK and eIF2α phosphorylation, together with reduced ATF6 nuclear translocation as well as the downregulation of GRP78 and CHOP. Interestingly, D4F facilitated gly-HDL-triggered activation of autophagy, measured as elevated levels of beclin-1, LC3-II, and ATG5 expressions in macrophages. Furthermore, the inhibition effect of D4F on gly-HDL-induced ER stress-CHOP-induced apoptosis of macrophages was restrained after beclin-1 siRNA and 3-methyladenine (3-MA, an inhibitor of autophagy) treatments, while this effect was further reinforced after rapamycin (Rapa, an inducer of autophagy) treatment. Furthermore, administering D4F or Rapa to T2DM mice upregulated LC3-II and attenuated CHOP expression, cell apoptosis, and atherosclerotic lesions. However, the opposite results were obtained when 3-MA was administered to these mice. These results support that D4F effectively protects macrophages against gly-HDL-induced ER stress-CHOP-mediated apoptosis by promoting autophagy.

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Role of Circulating High-Density Lipoprotein and Triglycerides in Coronary Artery Disease: Risk and Prevention

Endocrinology and Metabolism Clinics of North America ◽

10.1016/s0889-8529(18)30326-8 ◽

1990 ◽

Vol 19 (2) ◽

pp. 299-309 ◽

Cited By ~ 10

Author(s):

David J. Gordon

Keyword(s):

Coronary Artery Disease ◽

Coronary Artery ◽

High Density Lipoprotein ◽

Disease Risk ◽

Density Lipoprotein ◽

High Density ◽

Coronary Artery Disease Risk ◽

Artery Disease

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Triglyceride to high density lipoprotein cholesterol ratio, total cholesterol to high density lipoprotein cholesterol ratio and low ankle brachial index in an elderly population

VASA ◽

10.1024/0301-1526/a000348 ◽

2014 ◽

Vol 43 (3) ◽

pp. 189-197 ◽

Cited By ~ 10

Author(s):

Yiqiang Zhan ◽

Jinming Yu ◽

Rongjing Ding ◽

Yihong Sun ◽

Dayi Hu

Keyword(s):

High Density Lipoprotein ◽

Total Cholesterol ◽

High Density Lipoprotein Cholesterol ◽

Ankle Brachial Index ◽

Density Lipoprotein ◽

High Density ◽

Lipoprotein Cholesterol ◽

Lipid Lowering ◽

Cholesterol Ratio ◽

Potential Biomarker

Background: The associations of triglyceride (TG) to high-density lipoprotein cholesterol ratio (HDL‑C) and total cholesterol (TC) to HDL‑C ratio and low ankle brachial index (ABI) were seldom investigated. Patients and methods: A population based cross-sectional survey was conducted and 2982 participants 60 years and over were recruited. TG, TC, HDL‑C, and low-density lipoprotein cholesterol (LDL-C) were assessed in all participants. Low ABI was defined as ABI ≤ 0.9 in either leg. Multiple logistic regression models were applied to study the association between TG/HDL‑C ratio, TC/HDL‑C ratio and low ABI. Results: The TG/HDL‑C ratios for those with ABI > 0.9 and ABI ≤ 0.9 were 1.28 ± 1.20 and 1.48 ± 1.13 (P < 0.0001), while the TC/HDL‑C ratios were 3.96 ± 1.09 and 4.32 ± 1.15 (P < 0.0001), respectively. After adjusting for age, gender, body mass index, obesity, current drinking, physical activity, hypertension, diabetes, lipid-lowering drugs, and cardiovascular disease history, the odds ratios (ORs) with 95 % confidence intervals (CIs) of low ABI for TG/HDL‑C ratio and TC/HDL‑C ratio were 1.10 (0.96, 1.26) and 1.34 (1.14, 1.59) in non-smokers. When TC was further adjusted, the ORs (95 % CIs) were 1.40 (0.79, 2.52) and 1.53 (1.21, 1.93) for TG/HDL‑C ratio and TC/HDL‑C ratio, respectively. Non-linear relationships were detected between TG/HDL‑C ratio and TC/HDL‑C ratio and low ABI in both smokers and non-smokers. Conclusions: TC/HDL‑C ratio was significantly associated with low ABI in non-smokers and the association was independent of TC, TG, HDL‑C, and LDL-C. TC/HDL‑C might be considered as a potential biomarker for early peripheral arterial disease screening.

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