Increased inflammation, endoplasmic reticulum stress and oxidative stress in endothelial and macrophage cells exacerbate atherosclerosis in ApoCIII transgenic mice

Article

作者: Yingchun, Han ; Yahong, Ma ; Xiaohong, Zhang ; Jiangping, Wen ; Xiaokui, He

BACKGROUNDOverexpression of apolipoprotein CIII (ApoCIII) leads to hypertriglyceridemia (HTG) which promotes atherosclerosis development. However, it remains unclear whether ApoCIII affects the atherosclerosis alone by promoting the inflammation and endoplasmic reticulum (ER) stress, or in combination with HTG.METHODSTransgenic (ApoCIIItg) mouse models were used to investigate the atherogenic role of ApoCIII. Since endothelial cells and macrophages play crucial roles in atherosclerosis, we examined whether triglyceride-rich lipoproteins (TRLs), the major lipoproteins, in plasma of ApoCIIItg mice affect inflammation and ER stress levels in these cells. To further investigate the role of ApoCIII and triglyceride, we incubated HUVECs cells and peritoneal macrophages with TRLs with or without ApoCIII.RESULTSIncreased inflammation and ER stress were found in the aorta of ApoCIIItg mice. TRLs increased ER stress and oxidative stress in HUVECs and macrophages in a dose dependent. Moreover, TRLs together with ApoCIII could induce a higher inflammation level than TRLs alone in these cells.CONCLUSIONSBoth TRLs and ApoCIII contribute to the progression of atherosclerosis, and the modulation of TRLs and ApoCIII may represent a novel therapeutic approach against HTG induced atherosclerosis.

2017-11-01·Diabetologia1区 · 医学

VLDL and apolipoprotein CIII induce ER stress and inflammation and attenuate insulin signalling via Toll-like receptor 2 in mouse skeletal muscle cells

1区 · 医学

Article

作者: Barroso, Emma ; Gumà, Anna ; Montori, Marta ; Li, Diana ; Escolà-Gil, Joan Carles ; Kohan, Alison B ; Vázquez-Carrera, Manuel ; Palomer, Xavier ; Pizarro, Javier ; Cedó, Lídia ; Botteri, Gaia

AIM/HYPOTHESISHere, our aim was to examine whether VLDL and apolipoprotein (apo) CIII induce endoplasmic reticulum (ER) stress, inflammation and insulin resistance in skeletal muscle.METHODSStudies were conducted in mouse C2C12 myotubes, isolated skeletal muscle and skeletal muscle from transgenic mice overexpressing apoCIII.RESULTSC2C12 myotubes exposed to VLDL showed increased levels of ER stress and inflammatory markers whereas peroxisome proliferator-activated receptor γ co-activator 1α (PGC-1α) and AMP-activated protein kinase (AMPK) levels were reduced and the insulin signalling pathway was attenuated. The effects of VLDL were also observed in isolated skeletal muscle incubated with VLDL. The changes caused by VLDL were dependent on extracellular signal-regulated kinase (ERK) 1/2 since they were prevented by the ERK1/2 inhibitor U0126 or by knockdown of this kinase by siRNA transfection. ApoCIII mimicked the effects of VLDL and its effects were also blocked by ERK1/2 inhibition, suggesting that this apolipoprotein was responsible for the effects of VLDL. Skeletal muscle from transgenic mice overexpressing apoCIII showed increased levels of some ER stress and inflammatory markers and increased phosphorylated ERK1/2 levels, whereas PGC-1α levels were reduced, confirming apoCIII effects in vivo. Finally, incubation of myotubes with a neutralising antibody against Toll-like receptor 2 abolished the effects of apoCIII on ER stress, inflammation and insulin resistance, indicating that the effects of apoCIII were mediated by this receptor.CONCLUSIONS/INTERPRETATIONThese results imply that elevated VLDL in diabetic states can contribute to the exacerbation of insulin resistance by activating ERK1/2 through Toll-like receptor 2.

2014-04-01·Cellular and Molecular Life Sciences2区 · 生物学

Apolipoprotein CIII hyperactivates β cell CaV1 channels through SR-BI/β1 integrin-dependent coactivation of PKA and Src

2区 · 生物学

Article

作者: Juntti-Berggren, Lisa ; Shi, Yue ; Catterall, William A. ; Yu, Jia ; Yang, Guang ; Westenbroek, Ruth ; Berggren, Per-Olof ; Yang, Shao-Nian ; Yu, Lina

Apolipoprotein CIII (ApoCIII) not only serves as an inhibitor of triglyceride hydrolysis but also participates in diabetes-related pathological events such as hyperactivation of voltage-gated Ca(2+) (CaV) channels in the pancreatic β cell. However, nothing is known about the molecular mechanisms whereby ApoCIII hyperactivates β cell CaV channels. We now demonstrate that ApoCIII increased CaV1 channel open probability and density. ApoCIII enhanced whole-cell Ca(2+) currents and the CaV1 channel blocker nimodipine completely abrogated this enhancement. The effect of ApoCIII was not influenced by individual inhibition of PKA, PKC, or Src. However, combined inhibition of PKA, PKC, and Src counteracted the effect of ApoCIII, similar results obtained by coinhibition of PKA and Src. Moreover, knockdown of β1 integrin or scavenger receptor class B type I (SR-BI) prevented ApoCIII from hyperactivating β cell CaV channels. These data reveal that ApoCIII hyperactivates β cell CaV1 channels through SR-BI/β1 integrin-dependent coactivation of PKA and Src.

100 项与 APOCIII program (Biocrine) 相关的药物交易

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