Precise redox balance is essential for the optimum health and physiological function of the human body. Furthermore, an unbalanced redox state is widely believed to be part of numerous diseases, ultimately resulting in death. In this review, we discuss the relationship between redox balance and cardiovascular disease (CVD). In various animal models, excessive oxidative stress has been associated with increased atherosclerotic plaque formation, which is linked to the inflammation status of several cell types. However, various antioxidants can defend against reactive oxidative stress, which is associated with an increased risk of CVD and mortality. The different cardiovascular effects of these antioxidants are presumably due to alterations in the multiple pathways that have been mechanistically linked to accelerated atherosclerotic plaque formation, macrophage activation, and endothelial dysfunction in animal models of CVD, as well as in in vitro cell culture systems. Autophagy is a regulated cell survival mechanism that removes dysfunctional or damaged cellular organelles and recycles the nutrients for the generation of energy. Furthermore, in response to atherogenic stress, such as the generation of reactive oxygen species, oxidized lipids, and inflammatory signaling between cells, autophagy protects against plaque formation. In this review, we characterize the broad spectrum of oxidative stress that influences CVD, summarize the role of autophagy in the content of redox balance-associated pathways in atherosclerosis, and discuss potential therapeutic approaches to target CVD by stimulating autophagy.

Background: Non-alcoholic fatty liver disease (NAFLD) has been increasing in association with the epidemic of obesity and diabetes. Peroxisomes are single membrane-enclosed organelles that play a role in the metabolism of lipid and reactive oxygen species. The present study examined the role of peroxisomes in high-fat diet (HFD)-induced NAFLD using fenofibrate, a peroxisome proliferator-activated receptor α (PPARα) agonist. Methods: Eight-week-old male C57BL/6J mice were fed either a normal diet or HFD for 12 weeks, and fenofibrate (50 mg/kg/day) was orally administered along with the initiation of HFD. Results: HFD-induced liver injury as measured by increased alanine aminotransferase, inflammation, oxidative stress, and lipid accumulation was effectively prevented by fenofibrate. Fenofibrate significantly increased the expression of peroxisomal genes and proteins involved in peroxisomal biogenesis and function. HFD-induced attenuation of peroxisomal fatty acid oxidation was also significantly restored by fenofibrate, demonstrating the functional significance of peroxisomal fatty acid oxidation. In Ppara deficient mice, fenofibrate failed to maintain peroxisomal biogenesis and function in HFD-induced liver injury. Conclusion The present data highlight the importance of PPARα-mediated peroxisomal fitness in the protective effect of fenofibrate against NAFLD.

Obesity and type 2 diabetes mellitus are world-wide health problems, and lack of understanding of their linking mechanism is one reason for limited treatment options. We determined if genetic deletion of vimentin, a type 3 intermediate filament, affects obesity and type 2 diabetes mellitus.

Macrophage cholesterol efflux is a central step in reverse cholesterol transport, which helps to maintain cholesterol homeostasis and to reduce atherosclerosis. Lipophagy has recently been identified as a new step in cholesterol ester hydrolysis that regulates cholesterol efflux, since it mobilizes cholesterol from lipid droplets of macrophages via autophagy and lysosomes. In this review, we briefly discuss recent advances regarding the mechanisms of the cholesterol efflux pathway in macrophage foam cells, and present lipophagy as a therapeutic target in the treatment of atherosclerosis.
Atherosclerosis ; Autophagy ; Cholesterol* ; Foam Cells ; Homeostasis ; Hydrolysis ; Lipid Droplets ; Lysosomes ; Macrophages*

The tumor necrosis factor receptor superfamily (TNFRSF), which includes CD40, LIGHT, and OX40, plays important roles in the initiation and progression of cardiovascular diseases, involving atherosclerosis. CD137, a member of TNFRSF, is a well-known activation-induced T cell co-stimulatory molecule and has been reported to be expressed in human atherosclerotic plaque lesions, and plays pivotal roles in mediating disease processes. In this review, we focus on and summarize recent advances in mouse studies on the involvement of CD137 signaling in the pathogenesis and plaque stability of atherosclerosis, thereby highlighting a valuable therapeutic target in atherosclerosis.
Animals ; Atherosclerosis* ; Cardiovascular Diseases ; Humans ; Mice ; Negotiating ; Plaque, Atherosclerotic ; Receptors, Tumor Necrosis Factor

Autophagy is a life-sustaining process by which cytoplasmic constituents are segregated in double-lipid bilayer membrane vesicles and undergo degradation into lysosomes. In recent studies, the basal autophagy is an indispensable process mediating proper vascular function in the body. Moreover, autophagy activated by many stress-related stimuli in the arterial wall protects endothelial cells and smooth muscle cells against cell death and the progression of vascular disease including atherosclerosis. Autophagy is protective to atherosclerosis during early stage but becomes dysfunctional in advanced atherosclerotic lesions. Following this finding, the need is emphasized which pharmacological development with compounds that activate the protective effects of autophagy in the vascular disease. Autophagy stimulated by oral or vascular delivery of rapamycin or derivatives effectively suppressed the atherosclerotic plaque growth and plaque destabilization. In this review, the recent finding is summarized on the role of autophagy in atherosclerosis and find out whether the activation or rescue of autophagy could provide a breakthrough in the treatment of atherosclerosis.
Atherosclerosis* ; Autophagy* ; Cell Death ; Cytoplasm ; Endothelial Cells ; Lysosomes ; Membranes ; Myocytes, Smooth Muscle ; Negotiating ; Plaque, Atherosclerotic ; Sirolimus ; Vascular Diseases

KR-31543, (2S, 3R, 4S)-6-amino-4-[N-(4-chlorophenyl)-N-(2-methyl-2H-tetrazol-5-ylmethyl) amino]-3,4-dihydro-2-dimethyoxymethyl-3-hydroxy-2-methyl-2H-1-benz opyran is a new neuroprotective agent for ischemia-reperfusion damage. It has also been reported that KR-31543 has protective effects on lipid peroxidation and H2O2-induced reactive oxygen species production. In this study, we investigated the anti-inflammatory and anti-atherogenic properties of KR-31543. We observed that KR-31543 treatment reduced the production of MCP-1, IL-8, and VCAM-1 in HUVECs, and of MCP-1 and IL-6 in THP-1 human monocytes. We also examined the effect of KR-31543 on monocytes migration in vitro. KR-31543 treatment effectively reduced the migration of THP-1 human monocytes to the HUVEC monolayer in a dose-dependent manner. We next examined the effects of this compound on atherogenesis in LDL receptor deficient (Ldlr-/-) mice. After 10 weeks of western diet, the formation of atherosclerotic lesion in aorta was reduced in the KR-31543-treated group compared to the control group. The accumulation of macrophages in lesion was also reduced in KR-31543 treated group. However, the plasma levels of total cholesterol, HDL, LDL, and triglyceride were not affected by KR-31543 treatment. Taken together, these results show that KR-31543 has anti-inflammatory properties on human monocytes and endothelial cells, and inhibits fatty streak lesion formation in mouse model of atherosclerosis, suggesting the potential of KR-31543 for the treatment for atherosclerosis.
Animals ; Aorta/pathology ; Atherosclerosis/blood/*drug therapy/pathology ; Benzopyrans/*pharmacology/therapeutic use ; Cholesterol, HDL/blood ; Cholesterol, LDL/blood ; Diet ; Disease Models, Animal ; Human Umbilical Vein Endothelial Cells/drug effects/metabolism ; Inflammation Mediators/*metabolism ; Interleukin-6/metabolism ; Interleukin-8/metabolism ; Macrophages/metabolism ; Mice ; Mice, Transgenic ; Monocytes/drug effects/*metabolism ; Neuroprotective Agents/*pharmacology/therapeutic use ; Receptors, CCR2/metabolism ; Receptors, LDL/genetics ; Tetrazoles/*pharmacology/therapeutic use ; Transendothelial and Transepithelial Migration/drug effects ; Triglycerides/blood ; Vascular Cell Adhesion Molecule-1/metabolism

In this study, the synergistic effect of 6-[4-(1-cyclohexyl-1H-tetrazol-5-yl) butoxy]-3,4-dihydro-2(1H)-quinolinone (cilostazol) and Ginkgo biloba extract (GbE) was examined in apolipoprotein E (ApoE) null mice. Co-treatment with GbE and cilostazol synergistically decreased reactive oxygen species (ROS) production in ApoE null mice fed a high-fat diet. Co-treatment resulted in a significantly decreased atherosclerotic lesion area compared to untreated ApoE mice. The inflammatory cytokines and adhesion molecules such as monocyte chemoattractant-1 (MCP-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), and VCAM-1 which can initiate atherosclerosis were significantly reduced by the co-treatment of cilostazol with GbE. Further, the infiltration of macrophages into the intima was decreased by co-treatment. These results suggest that co-treatment of GbE with cilostazol has a more potent anti-atherosclerotic effect than treatment with cilostazol alone in hyperlipidemic ApoE null mice and could be a valuable therapeutic strategy for the treatment of atherosclerosis.
Animals ; Apolipoproteins E/genetics/physiology ; Atherosclerosis/*drug therapy ; Cytokines/metabolism ; Disease Models, Animal ; Drug Synergism ; Ginkgo biloba/*chemistry ; Humans ; Macrophages/cytology/drug effects ; Male ; Mice ; Mice, Nude ; Plant Extracts/*administration & dosage/chemistry ; Reactive Oxygen Species/*metabolism ; Tetrazoles/*administration & dosage

A variety of benzylidenethiazole analogs have been demonstrated to inhibit 5-lipoxygenase (5-LOX). Here we report the anti-atherogenic potential of 5-(4-hydroxy-2,3,5-trimethylbenzylidene) thiazolidin-2,4-dione (HMB-TZD), a benzylidenethiazole analog, and its potential mechanism of action in LDL receptor-deficient (Ldlr-/-) mice. HMB-TZD Treatment reduced leukotriene B4 (LTB4) production significantly in RAW264.7 macrophages and SVEC4-10 endothelial cells. Macrophages or endothelial cells pre-incubated with HMB-TZD for 2 h and then stimulated with lipopolysaccharide or tumor necrosis factor-alpha (TNF-alpha) displayed reduced cytokine production. Also, HMB-TZD reduced cell migration and adhesion in accordance with decreased proinflammatory molecule production in vitro and ex vivo. HMB-TZD treatment of 8-week-old male Ldlr-/- mice resulted in significantly reduced atherosclerotic lesions without a change to plasma lipid profiles. Moreover, aortic expression of pro-atherogenic molecules involved in the recruitment of monocytes to the aortic wall, including TNF-alpha , MCP-1, and VCAM-1, was downregulated. HMB-TZD also reduced macrophage infiltration into atherosclerotic lesions. In conclusion, HMB-TZD ameliorates atherosclerotic lesion formation possibly by reducing the expression of proinflammatory molecules and monocyte/macrophage recruitment to the lesion. These results suggest that HMB-TZD, and benzylidenethiazole analogs in general, may have therapeutic potential as treatments for atherosclerosis.
Animals ; Atherosclerosis/*drug therapy ; Cell Adhesion/drug effects ; Cell Line ; Cell Movement/drug effects ; Chemokine CCL2/metabolism ; Dinoprostone/metabolism ; Enzyme-Linked Immunosorbent Assay ; Humans ; Leukotriene B4/metabolism ; Macrophages/cytology/drug effects ; Male ; Mice ; Monocytes/cytology/*drug effects ; Random Allocation ; Receptors, LDL/deficiency/genetics ; Thiazolidinediones/*therapeutic use ; Tumor Necrosis Factor-alpha/pharmacology

We investigated the effect of tilianin upon inducible nitric oxide synthesis in the plasma of low-density lipoprotein receptor knock-out (Ldlr-/-) mice fed with high cholesterol diet and in primary peritoneal macrophages of Ldlr-/- mice. High cholesterol diet induced nitric oxide production in the plasma of Ldlr-/- mice. Tilianin reduced the level of nitric oxide (NO) in plasma from Ldlr-/- mice induced by the high cholesterol diet. Tilianin also inhibited the NO production from the primary culture of peritoneal macrophages treated with lipopolysaccharide. The inhibition of NO production was caused by the suppression of inducible nitric oxide synthase (iNOS) gene expression in peritoneal macrophages isolated from Ldlr-/- mice. Moreover, tilianin inhibited the transcriptional activation of iNOS promoter that has NF-kappa B binding element. Thus, these results provide the first evidence that tilianin inhibit iNOS expression and production of NO and may act as a potential anti-inflammatory agent.
Tyrosine/analogs & derivatives/metabolism ; Tissue Distribution ; Sinus of Valsalva/metabolism/pathology/ultrastructure ; Receptors, LDL/*genetics ; Promoter Regions (Genetics)/drug effects ; Nitric Oxide Synthase Type II/*metabolism ; Nitric Oxide/biosynthesis/blood ; NF-kappa B/metabolism ; Mice, Knockout ; Mice ; Male ; Inflammation/metabolism ; Glycosides/*pharmacology ; Flavonoids/*pharmacology ; Down-Regulation/drug effects ; Atherosclerosis/metabolism ; Animals