scholarly journals Puerarin Inhibits oxLDL-Induced Macrophage Activation and Foam Cell Formation in Human THP1 Macrophage

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Heng Zhang ◽  
Zhenhua Zhai ◽  
Hongyu Zhou ◽  
Yao Li ◽  
Xiaojie Li ◽  
...  

Puerarin, an isoflavone derived from Kudzu roots, has been widely used for treatment of cardiovascular and cerebral vascular diseases in China and other Asian countries. However, the underlying mechanisms are largely unknown. The present study investigated whether puerarin inhibited atherogenic lipid oxLDL-mediated macrophage activation and foam cell formation in human THP1 macrophage. Treatment with oxLDL significantly increased the mRNA expression of proinflammatory cytokines tumor necrosis factorα(TNFα, 160%) and interleukin (IL) 1β(13 fold) accompanied by upregulation of toll-like receptor 4 (TLR4, 165%) and the ratio of phospho-IκBα/IκBαin THP1 macrophage. Puerarin dose-dependently prevented an increase in oxLDL-induced proinflammatory gene expression with downregulation of TLR4 and the ratio of phospho-IκBα/IκBα. Furthermore, puerarin prevented oxLDL-mediated lipid deposition and foam cell formation associated with downregulation of scavenger receptor CD36. Flow cytometry analysis showed that puerarin reduced the number of early apoptotic cells of macrophages induced by oxLDL. Our results show that puerarin has anti-inflammatory and antiatherogenic effects in vitro; the underlying mechanisms may involve the inhibition of TLR4/NFκB pathway and downregulation of CD36 expression. The results from the present study provide scientific evidence and may expand our armamentarium to use puerarin for prevention and treatment of cardiovascular and atherosclerotic diseases.

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Heng Zhang ◽  
Zhenhua Zhai ◽  
Yao Li ◽  
Yueping Shi ◽  
Ming-sheng Zhou

Puerarin, a major isoflavonoid compound isolated from the Chinese herb Kudzu roots, has been a long history and widely used for treatment of cerebral and cardiovascular diseases in China and other Asian countries, including coronary artery disease, heart failure and myocardial infarction. However, the underlying mechanisms by which puerarin inhibits vascular atherogenic diseases are largely unknown. The activated macrophages release of inflammatory cytokines and uptake of oxLDL forming foam cells are critical for the development of atherosclerotic plaque. The present study investigated whether puerarin inhibited atherogenic lipid oxLDL-mediated macrophage activation and foam cell formation in human THP1 macrophage. The Cells were cultured and differentiated into macrophages by pre-incubation with 100 ng/ml PMA. Treatment with oxLDL (50 μg/ml) significantly increased the mRNA expression of proinflammatory cytokines tumor necrosis factor α(TNFα, 160%) and interleukin (IL)1β(13 fold) accompanied by upregulation of toll-like receptor 4 (TLR4, 165%) and the ratio of phospho-I κ Bα/I κ Bα in THP1 macrophage. Puerarin dose-dependently prevented an increase in oxLDL-induced proinflammatory gene expression with downregulation of TLR4 and the ratio of phospho-I κ Bα/I κ Bα. Furthermore, puerarin prevented oxLDL-mediated lipid deposition and foam cell formation associated with downregulation of scavenger receptor CD36. Flow cytometry analysis showed that puerarin reduced the number of early apoptotic cells of macrophages induced by oxLDL. Our results show that puerarin has anti-inflammatory and anti-atherogenic effects in vitro, the underling mechanisms may involve the inhibition of TLR4/NF κ B pathway and downregulation of CD36 expression. The results from the present study provide scientific evidence and may expand our armamentarium to use puerarin for prevention and treatment of cardiovascular and atherosclerotic diseases.


2021 ◽  
pp. 174181
Author(s):  
Jianzhen Lei ◽  
Jingheng Ye ◽  
Rong She ◽  
Ruyi Zhang ◽  
Yanan Wang ◽  
...  

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Christina Grothusen ◽  
Harald Schuett ◽  
Stefan Lumpe ◽  
Andre Bleich ◽  
Silke Glage ◽  
...  

Introduction: Atherosclerosis is a chronic inflammatory disease of the cardiovascular system which may result in myocardial infarction and sudden cardiac death. While the role of pro-inflammatory signaling pathways in atherogenesis has been well characterized, the impact of their negative regulators, e.g. suppressor of cytokine signaling (SOCS)-1 remains to be elucidated. Deficiency of SOCS-1 leads to death 3 weeks post-partum due to an overwhelming inflammation caused by an uncontrolled signalling of interferon-gamma (IFNγ). This phenotype can be rescued by generating recombination activating gene (rag)-2, SOCS-1 double knock out (KO) mice lacking mature lymphocytes, the major source of IFNγ. Since the role of SOCS-1 during atherogenesis is unknown, we investigated the impact of a systemic SOCS-1 deficiency in the low-density lipoprotein receptor (ldlr) KO model of atherosclerosis. Material and Methods: socs-1 −/− /rag-2 −/− deficient mice were crossed with ldlr-KO animals. Mice were kept under sterile conditions on a normal chow diet. For in-vitro analyses, murine socs-1 −/− macrophages were stimulated with native low density lipoprotein (nLDL) or oxidized (ox)LDL. SOCS-1 expression was determined by quantitative PCR and western blot. Foam cell formation was determined by Oil red O staining. Results: socs-1 −/− /rag-2 −/− /ldlr −/− mice were born according to mendelian law. Tripel-KO mice showed a reduced weight and size, were more sensitive to bacterial infections and died within 120 days (N=17). Histological analyses revealed a systemic, necrotic, inflammation in Tripel-KO mice. All other genotypes developed no phenotype. In-vitro observations revealed that SOCS-1 mRNA and protein is upregulated in response to stimulation with oxLDL but not with nLDL. Foam cell formation of socs-1 −/− macrophages was increased compared to controls. Conclusion: SOCS-1 seemingly controls critical steps of atherogenesis by modulating foam cell formation in response to stimulation with oxLDL. SOCS-1 deficiency in the ldlr-KO mouse leads to a lethal inflammation. These observations suggest a critical role for SOCS-1 in the regulation of early inflammatory responses in atherogenesis.


2017 ◽  
Vol 37 (suppl_1) ◽  
Author(s):  
Catherine A Reardon ◽  
Amulya Lingaraju ◽  
Kelly Q Schoenfelt ◽  
Guolin Zhou ◽  
Ning-Chun Liu ◽  
...  

Type 2 diabetics have a higher risk for atherosclerosis, but the mechanisms underlying the increased risk are poorly understood. Macrophages, which are activated in type 2 diabetes (T2D) and have a role in all stages of atherogenesis, are an attractive link. Our hypothesis is that T2D promotes macrophage dysfunction to promote atherosclerosis. To investigate the relationship between T2D and macrophage dysfunction, we used a proteomics approach to identify dysregulated proteins secreted from peritoneal macrophages in a diet induced mouse model of obesity and insulin resistance in the absence of hypercholesterolemia. Twenty-seven T2D responsive proteins were identified that predict defects in many of the critical functions of macrophages in atherosclerosis (e.g. decreased apoE- cholesterol efflux; decreased MFGE8 – efferocytosis, increased MMP12- matrix degradation). The macrophages from lean and obese mice were not lipid loaded, but the obese macrophages accumulated significantly more cholesterol when exposed to high levels of atherogenic lipoproteins in vitro suggesting that dysregulation of the T2D responsive proteins in diabetic mice render macrophages more susceptible to cholesterol loading. Importantly, many of these same protein changes, which were present in atherosclerotic Ldlr-/- mice with T2D, were normalized when these mice were fed non-diabetogenic hypercholesterolemic diets. Thus, foam cell formation in the presence and absence of T2D produces distinct effects on macrophage protein levels, and hence function. Further, we identify IFNγ as a mediator of the T2D responsive protein dysfunction. IFNγ, but not other cytokines, insulin or glucose, promote the T2D responsive protein dysregulation and increased susceptibility to cholesterol accumulation in vitro and the dysregulation is not observed in macrophage foam cells obtained from obese, diabetic IFNγ receptor 1 knockout animals. We also demonstrate that IFNγ can target these proteins in arterial wall macrophages in vivo . These studies suggest that IFNγ is an important mediator of macrophage dysfunction in T2D that may contribute to the enhanced cardiovascular risk in these patients.


2010 ◽  
Vol 11 (2) ◽  
pp. 60
Author(s):  
N. Younis ◽  
H. Soran ◽  
R. Sharma ◽  
P. Pemberton ◽  
V. Charlton-Menys ◽  
...  

Blood ◽  
1996 ◽  
Vol 87 (5) ◽  
pp. 2020-2028 ◽  
Author(s):  
HY Huh ◽  
SF Pearce ◽  
LM Yesner ◽  
JL Schindler ◽  
RL Silverstein

Abstract CD36 is an 88-kD integral membrane glycoprotein expressed on monocytes, platelets, and certain microvascular endothelium serving distinct cellular functions both as an adhesive receptor for thrombospondin, collagen, and Plasmodium falciparum-infected erythrocytes, and as a scavenger receptor for oxidized low-density lipoprotein and apoptotic neutrophils. In this study, we examined the expression of CD36 during in vitro differentiation of peripheral blood monocytes into culture- derived macrophages. Steady-state mRNA levels of CD36 showed a transient eightfold increase during monocyte-to-macrophage differentiation, peaking at the early macrophage stage (days 3 or 4 in culture), following a gradual decrease back to baseline levels by the mature macrophage stage (days 7 or 8 in culture). Immunoblotting with monoclonal antibodies to CD36 supported this transient, yet significant (8- to 10-fold) increase in total protein levels of CD36. The increased CD36 protein was observed at the plasma membrane, whereas an intracellular pool of CD36 was also detected from day 2 to day 6 in culture through indirect immunofluorescence. A concomitant twofold increase in the cells' ability to bind 125I-thrombospondin at the early macrophage stage (day 4) verified the functional competency of the plasma membrane localized CD36, and supported the presence of an intracellular pool of CD36. The in vitro differentiated macrophages as well as alveolar macrophages remained responsive to macrophage colony- stimulating factor (M-CSF), a known transcriptional regulator of monocyte CD36. The M-CSF-induced macrophages resulted in enhanced foam cell formation, which was inhibitable with monoclonal antibodies to CD36. Thus, the transient expression of CD36 during monocyte-to- macrophage differentiation, and the ability of M-CSF to maintain macrophage CD36 at elevated levels, may serve as a critical process in dictating the functional activity of CD36 during inflammatory responses and atherogenesis.


Endocrinology ◽  
2007 ◽  
Vol 148 (3) ◽  
pp. 1009-1018 ◽  
Author(s):  
Amélie Rodrigue-Way ◽  
Annie Demers ◽  
Huy Ong ◽  
André Tremblay

Whereas the uptake of oxidized lipoproteins by scavenger receptor CD36 in macrophages has been associated with foam cell formation and atherogenesis, little is known about the role of CD36 in regulating lipid metabolism in adipocytes. Here we report that treatment of 3T3-L1 adipocytes with hexarelin, a GH-releasing peptide that interacts with CD36, resulted in a depletion of intracellular lipid content with no significant change in CD36 expression. Microarray analysis revealed an increased pattern in several genes involved in fatty acid mobilization toward the mitochondrial oxidative phosphorylation process in response to hexarelin. Interestingly, many of these up-regulated genes are known targets of peroxisomal proliferator-activated receptor (PPAR)-γ, such as FATP, CPT-1, and F1-ATPase, suggesting that adipocyte response to hexarelin may involve PPARγ activation. Expression studies also indicate an increase in thermogenic markers PPARγ coactivator 1α and uncoupling protein-1, which are normally expressed in brown adipocytes. Electron microscopy of hexarelin-treated 3T3-L1 adipocytes showed an intense and highly organized cristae formation that spans the entire width of mitochondria, compared with untreated cells, and cytochrome c oxidase activity was enhanced by hexarelin, two features characteristic of highly oxidative tissues. A similar mitochondrial phenotype was detected in epididymal white fat of mice treated with hexarelin, along with an increased expression of thermogenic markers that was lost in treated CD36-null mice, suggesting that the ability of hexarelin to promote a brown fat-like phenotype also occurs in vivo and is dependent on CD36. These results provide a potential role for CD36 to impact the overall metabolic activity of fat usage and mitochondrial biogenesis in adipocytes.


2007 ◽  
Vol 35 (3) ◽  
pp. 470-471 ◽  
Author(s):  
R. Cabello-Moruno ◽  
J.S. Perona ◽  
V. Ruiz-Gutierrez

Metabolic and epidemiologic studies support the idea that the type of dietary fat is more important than the total amount of fat with respect to the development of atherosclerosis and the risk of cardiovascular heart disease. Dietary fat is carried in CMs (chylomicrons), which can be taken up by macrophages without need of further oxidation, leading to the formation of foam cells and initiating or aggravating the atherogenic process. Evidence from different studies has shown that dietary fat can influence the composition and size of TRLs (triacylglycerol-rich lipoproteins), which might modulate their atherogenicity to a certain extent. In particular, experiments in vitro have shown the anti-atherogenic effects of minor components from olive oil when forming part of TRL, as these particles give minor lipid components the opportunity to interact with the cells implicated in endothelial dysfunction and atherogenesis. However, the exact mechanisms mediating CM uptake by macrophages still remain unclear. Thus further studies are needed to understand how the modifications of TRL composition caused by dietary fats could modulate the expression of macrophage receptors and foam cell formation, or even improve the atherogenic risk of these particles.


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