Abstract 306: Deficiency of ROCK1 in Macrophages Protects Against Atherosclerosis

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Hong-Wei Wang ◽  
Naotsugu Oyama ◽  
Yoshiyuki Rikitake ◽  
Shiro Kitamoto ◽  
Jonathan Gitlin ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Foam Cell ◽  
Vascular Inflammation ◽  
Low Density Lipoprotein ◽  
Cell Formation ◽  
Density Lipoprotein ◽  
Foam Cells ◽  
Foam Cell Formation ◽  
Low Density ◽  
Lipid Uptake

Background: Rho kinases (ROCKs) are serine-threonine protein kinases that regulate various cellular functions. There is increasing evidence that the RhoA/ROCK pathway plays an important pathophysiological role in cardiovascular diseases. However, direct evidence of which ROCK isoforms or target tissues are involved in the atherogenic process is still lacking. Objective: The aim of this study was to determine the effect of ROCK1 deficiency on atherogenesis and how ROCK1 affects key atherosclerosis-related macrophage function such as lipid uptake and chemotaxis. Methods: We utilized ROCK1 −/− mice and the atherosclerosis-prone apolipoprotein E knockout (apoE −/− ) mice or low-density lipoprotein receptor knockout (LDLR −/− ) mice to investigate the role of ROCK1 in the pathogenesis of atherosclerotic plaque formation. Bone marrow-derived macrophages from ROCK1 −/− and ROCK1 +/+ mice were used to investigate acetylated (Ac)LDL-mediated foam cell formation and chemotaxis. Results: Compared to atherosclerosis-prone apoE −/− mice, apoE −/− ROCK1 +/− mice had substantially less fatty streaks foam cells and atherosclerosis (77.0 ± 12.9 × 10 3 μm 2 versus 166.4 ± 14.6 × 10 3 μm 2 , P < 0.01). Atherosclerotic lesions were reduced also in LDLR −/− mice, whose bone marrow were replaced with bone marrow derived from ROCK1 −/− mice compared to ROCK1 +/+ recipients (181.5 ± 15.6 × 10 3 μm 2 versus 448.5 ± 33.3 × 10 3 μm 2 , P < 0.05). Bone marrow-derived ROCK1-deficient macrophages exhibited impaired chemotaxis to monocyte chemotactic protein-1 and showed reduced ability to take up lipids and to develop into foam cells when exposed to modified low density lipoprotein. Conclusion: These findings indicate that ROCK1 in macrophages is a critical mediator of foam cell formation, macrophage chemotaxis and atherogenesis, and suggest that macrophage ROCK1 may be an important therapeutic target for vascular inflammation and atherosclerosis.

scholarly journals Koala Biovar of Chlamydia pneumoniae Infects Human and Koala Monocytes and Induces Increased Uptake of Lipids In Vitro

2001 ◽  
Vol 69 (12) ◽  
pp. 7894-7897 ◽  
Author(s):  
Katie A. Coles ◽  
Peter Timms ◽  
David W. Smith
Keyword(s):  
Chlamydia Pneumoniae ◽  
Foam Cell ◽  
Low Density Lipoprotein ◽  
Cell Formation ◽  
Density Lipoprotein ◽  
Foam Cells ◽  
Foam Cell Formation ◽  
Low Density ◽  
Human Monocytes

ABSTRACT We examined the ability of the koala biovar of Chlamydia pneumoniae to infect both Hep-2 cells and human monocytes and the effect of infection on the formation of foam cells. The koala biovar produced large inclusions in both human and koala monocytes and in Hep-2 cells. Koala C. pneumoniae induced foam cell formation with and without added low-density lipoprotein, in contrast to TW183, which produced increased foam cell formation only in the presence of low-density lipoprotein.

scholarly journals Dihydrotestosterone Suppresses Foam Cell Formation and Attenuates Atherosclerosis Development

2010 ◽  
Vol 31 (3) ◽  
pp. 401-401
Author(s):  
Yang Qiu ◽  
Toshihiko Yanase ◽  
Haidi Hu ◽  
Tomoko Tanaka ◽  
Yoshihiro Nishi ◽  
...  
Keyword(s):  
Placebo Group ◽  
Foam Cell ◽  
Low Density Lipoprotein ◽  
Cell Formation ◽  
Density Lipoprotein ◽  
Foam Cells ◽  
Foam Cell Formation ◽  
Sham Operation ◽  
Low Density ◽  
Oxidized Low Density Lipoprotein

ABSTRACT The role of testosterone in atherosclerosis remains unclear because it is aromatized to estrogen. We investigated the effect of the nonaromatized natural androgen 5α-dihydrotestosterone (DHT) on the rabbit atherogenesis in relation to the proatherogenic molecule lectin-like oxidized-low-density lipoprotein receptor-1 (LOX-1) and its downstream molecules. Thirty-nine male New Zealand white rabbits were divided into four groups: 1) noncastrated group with normal chow diet (n = 6); 2) noncastrated group with high-cholesterol diet (HCD) (n = 10); 3) castrated group with HCD plus sc placebo pellet (n = 11); and 4) castrated group with HCD plus sc 150 mg DHT pellet (n = 12). Implantation of sc DHT or placebo pellet was performed at the time of castration. After castration or sham operation, the rabbits were fed the HCD for 8 wk, and plaque areas were assessed in the entire aorta. The HCD-induced increase in plaque area, which was most aggravated in the castration plus placebo group, was attenuated in the castration plus DHT group. Microscopic examination of the proximal descending aorta revealed that DHT significantly reduced HCD-induced foam cell formation, which was mostly composed of macrophages in the intima layer, compared with the placebo group. The decreased accumulation of foam cells with DHT treatment was accompanied by a marked reduction in the expression of LOX-1 mRNA in these cells. In cultured macrophages prepared from male wild-type mice that express the androgen receptor (AR), 1 × 10−8m and 1 × 10−9m DHT inhibited the formation of foam cells induced by oxidized low-density lipoprotein. Moreover, the expression of LOX-1 and inflammatory cytokines in the cultured macrophages was significantly suppressed by DHT. Such suppressive effects of DHT on foam cell formation and cytokine expression were not observed in cultured macrophages prepared from male AR-null mice, suggesting an involvement of AR in the mechanism. In conclusion, physiological levels of DHT attenuated the development of atherosclerosis in rabbits through the suppression of intimal foam cell formation of macrophage partly via the suppression of LOX-1 expression.

scholarly journals Dihydrotestosterone Suppresses Foam Cell Formation and Attenuates Atherosclerosis Development

Endocrinology ◽  
2010 ◽  
Vol 151 (7) ◽  
pp. 3307-3316 ◽  
Author(s):  
Yang Qiu ◽  
Toshihiko Yanase ◽  
Haidi Hu ◽  
Tomoko Tanaka ◽  
Yoshihiro Nishi ◽  
...  
Keyword(s):  
Placebo Group ◽  
Foam Cell ◽  
Low Density Lipoprotein ◽  
Cell Formation ◽  
Density Lipoprotein ◽  
Foam Cells ◽  
Foam Cell Formation ◽  
Sham Operation ◽  
Low Density ◽  
Oxidized Low Density Lipoprotein

The role of testosterone in atherosclerosis remains unclear because it is aromatized to estrogen. We investigated the effect of the nonaromatized natural androgen 5α-dihydrotestosterone (DHT) on the rabbit atherogenesis in relation to the proatherogenic molecule lectin-like oxidized-low-density lipoprotein receptor-1 (LOX-1) and its downstream molecules. Thirty-nine male New Zealand white rabbits were divided into four groups: 1) noncastrated group with normal chow diet (n = 6); 2) noncastrated group with high-cholesterol diet (HCD) (n = 10); 3) castrated group with HCD plus sc placebo pellet (n = 11); and 4) castrated group with HCD plus sc 150 mg DHT pellet (n = 12). Implantation of sc DHT or placebo pellet was performed at the time of castration. After castration or sham operation, the rabbits were fed the HCD for 8 wk, and plaque areas were assessed in the entire aorta. The HCD-induced increase in plaque area, which was most aggravated in the castration plus placebo group, was attenuated in the castration plus DHT group. Microscopic examination of the proximal descending aorta revealed that DHT significantly reduced HCD-induced foam cell formation, which was mostly composed of macrophages in the intima layer, compared with the placebo group. The decreased accumulation of foam cells with DHT treatment was accompanied by a marked reduction in the expression of LOX-1 mRNA in these cells. In cultured macrophages prepared from male wild-type mice that express the androgen receptor (AR), 1 × 10−8m and 1 × 10−9m DHT inhibited the formation of foam cells induced by oxidized low-density lipoprotein. Moreover, the expression of LOX-1 and inflammatory cytokines in the cultured macrophages was significantly suppressed by DHT. Such suppressive effects of DHT on foam cell formation and cytokine expression were not observed in cultured macrophages prepared from male AR-null mice, suggesting an involvement of AR in the mechanism. In conclusion, physiological levels of DHT attenuated the development of atherosclerosis in rabbits through the suppression of intimal foam cell formation of macrophage partly via the suppression of LOX-1 expression.

scholarly journals Protective Effect of Lusianthridin on Hemin-Induced Low-Density Lipoprotein Oxidation

2021 ◽  
Vol 14 (6) ◽  
pp. 567
Author(s):  
Su Wutyi Thant ◽  
Noppawan Phumala Morales ◽  
Visarut Buranasudja ◽  
Boonchoo Sritularak ◽  
Rataya Luechapudiporn
Keyword(s):  
Foam Cell ◽  
Low Density Lipoprotein ◽  
Cell Formation ◽  
Density Lipoprotein ◽  
Foam Cell Formation ◽  
Raw 264.7 ◽  
Low Density ◽  
Lipoprotein Oxidation ◽  
Raw 264.7 Macrophage Cells ◽  
Low Density Lipoprotein Oxidation

Oxidation of low-density lipoprotein (LDL) plays a crucial role in the pathogenesis of atherosclerosis. Hemin (iron (III)-protoporphyrin IX) is a degradation product of hemoglobin that can be found in thalassemia patients. Hemin is a strong oxidant that can cause LDL oxidation and contributes to atherosclerosis in thalassemia patients. Lusianthridin from Dendrobium venustrum is a phenolic compound that possesses antioxidant activity. Hence, lusianthridin could be a promising compound to be used against hemin-induced oxidative stress. The major goal of this study is to evaluate the protective effect of lusianthridin on hemin-induced low-density lipoprotein oxidation (he-oxLDL). Here, various concentrations of lusianthridin (0.25, 0.5, 1, and 2 µM) were preincubated with LDL for 30 min, then 5 µM of hemin was added to initiate the oxidation, and oxidative parameters were measured at various times of incubation (0, 1, 3, 6, 12, 24 h). Lipid peroxidation of LDL was measured by thiobarbituric reactive substance (TBARs) assay and relative electrophoretic mobility (REM). The lipid composition of LDL was analyzed by using reverse-phase HPLC. Foam cell formation with he-oxLDL in RAW 264.7 macrophage cells was detected by Oil Red O staining. The results indicated that lusianthridin could inhibit TBARs formation, decrease REM, decrease oxidized lipid products, as well as preserve the level of cholesteryl arachidonate and cholesteryl linoleate. Moreover, He-oxLDL incubated with lusianthridin for 24 h can reduce the foam cell formation in RAW 264.7 macrophage cells. Taken together, lusianthridin could be a potential agent to be used to prevent atherosclerosis in thalassemia patients.

scholarly journals Effects of Very Low Density Lipoprotein from Watanabe Heritable Hyperlipidemic Rabbits on Foam Cell Formation

1988 ◽  
Vol 16 (6) ◽  
pp. 877-879
Author(s):  
Kenji ISHII ◽  
Toru KITA ◽  
Yutaka NAGANO ◽  
Noriaki KUME ◽  
Masayuki YOKODE ◽  
...  
Keyword(s):  
Foam Cell ◽  
Low Density Lipoprotein ◽  
Cell Formation ◽  
Density Lipoprotein ◽  
Foam Cell Formation ◽  
Very Low Density Lipoprotein ◽  
Low Density

scholarly journals Signaling Pathways and Key Genes Involved in Regulation of foam Cell Formation in Atherosclerosis

Cells ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 584 ◽  
Author(s):  
Anastasia V. Poznyak ◽  
Wei-Kai Wu ◽  
Alexandra A. Melnichenko ◽  
Reinhard Wetzker ◽  
Vasily Sukhorukov ◽  
...  
Keyword(s):  
Foam Cell ◽  
Low Density Lipoprotein ◽  
Cell Formation ◽  
Density Lipoprotein ◽  
Foam Cells ◽  
Foam Cell Formation ◽  
Beneficial Effects ◽  
Complex Process ◽  
Experimental Therapies ◽  
Inflammatory Drugs

Atherosclerosis is associated with acute cardiovascular conditions, such as ischemic heart disease, myocardial infarction, and stroke, and is the leading cause of morbidity and mortality worldwide. Our understanding of atherosclerosis and the processes triggering its initiation is constantly improving, and, during the last few decades, many pathological processes related to this disease have been investigated in detail. For example, atherosclerosis has been considered to be a chronic inflammation triggered by the injury of the arterial wall. However, recent works showed that atherogenesis is a more complex process involving not only the immune system, but also resident cells of the vessel wall, genetic factors, altered hemodynamics, and changes in lipid metabolism. In this review, we focus on foam cells that are crucial for atherosclerosis lesion formation. It has been demonstrated that the formation of foam cells is induced by modified low-density lipoprotein (LDL). The beneficial effects of the majority of therapeutic strategies with generalized action, such as the use of anti-inflammatory drugs or antioxidants, were not confirmed by clinical studies. However, the experimental therapies targeting certain stages of atherosclerosis, among which are lipid accumulation, were shown to be more effective. This emphasizes the relevance of future detailed investigation of atherogenesis and the importance of new therapies development.

scholarly journals Neutrophils as a Novel Target of Modified Low-Density Lipoproteins and an Accelerator of Cardiovascular Diseases

2020 ◽  
Vol 21 (21) ◽  
pp. 8312
Author(s):  
Takashi Obama ◽  
Hiroyuki Itabe
Keyword(s):  
Cardiovascular Diseases ◽  
Inflammatory Responses ◽  
Foam Cell ◽  
Vascular Endothelial Cells ◽  
Low Density Lipoprotein ◽  
Cell Formation ◽  
Density Lipoprotein ◽  
Oxidative Modification ◽  
Foam Cell Formation ◽  
Low Density

Neutrophil extracellular traps (NETs) significantly contribute to various pathophysiological conditions, including cardiovascular diseases. NET formation in the vasculature exhibits inflammatory and thrombogenic activities on the endothelium. NETs are induced by various stimulants such as exogenous damage-associated molecular patterns (DAMPs). Oxidatively modified low-density lipoprotein (oxLDL) has been physiologically defined as a subpopulation of LDL that comprises various oxidative modifications in the protein components and oxidized lipids, which could act as DAMPs. oxLDL has been recognized as a crucial initiator and accelerator of atherosclerosis through foam cell formation by macrophages; however, recent studies have demonstrated that oxLDL stimulates neutrophils to induce NET formation and enhance NET-mediated inflammatory responses in vascular endothelial cells, thereby suggesting that oxLDL may be involved in cardiovascular diseases through neutrophil activation. As NETs comprise myeloperoxidase and proteases, they have the potential to mediate oxidative modification of LDL. This review summarizes recent updates on the analysis of NETs, their implications for cardiovascular diseases, and prospects for a possible link between NET formation and oxidative modification of lipoproteins.

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