Search

Purpose: It has been established that obstructive sleep apnea (OSA) is an independent risk factor for atherosclerosis. Chronic intermittent hypoxia (CIH) activates sympathoadrenal system and upregulates β3 adrenergic receptor (β3 AR). However, the effect of selective β3 AR agonist mirabegron in CIH-induced atherosclerosis remains unknown., Methods: We generated a CIH-induced atherosclerosis model through exposing ApoE -/- mice to CIH (8 h per day, cyclic inspiratory oxygen fraction 5-21%, 60-s cycle) for 6 weeks after 4-week high-fat dieting and investigated the effects of mirabegron, a selective β3 AR agonist, on CIH-induced atherosclerosis. The coronary endarterectomy (CE) specimens from coronary artery disease patients with OSA and without OSA were collected., Results: The expression of β3 AR was significantly elevated in CIH-induced atherosclerosis model. Furthermore, treatment with mirabegron (10mg/kg per day by oral administration for 6 weeks) ameliorated atherosclerosis in ApoE -/- mice in CIH but not in normoxia. Mechanistically, mirabegron activated β3 AR and ameliorated intraplaque oxidative stress by suppressing p22phox expression and reactive oxygen species (ROS) level. In addition, in human CE specimens, β3 AR was also upregulated associated with increased p22phox expression and ROS level both in the lumen and in the plaque of coronary artery in OSA subjects., Conclusion: This study first demonstrated that mirabegron impeded the progression of CIH-induced atherosclerosis, at least in part, via β3 AR-mediated oxidative stress, suggesting a promising therapeutic strategy for protecting against atherosclerosis induced by CIH., (© 2021. Springer Science+Business Media, LLC, part of Springer Nature.)

Objective: To determine the effects of interleukin (IL)-17A inhibition on experimental atherosclerosis., Methods and Results: ApoE(-/-) mice were treated with either rat anti-mouse IL-17A, mouse anti-mouse IL-17A or isotype-matched control antibodies for 12 weeks (n=8-10 per group). Ldlr(-/-) mice were transplanted with IL-17A-deficient or wild type bone marrow (n=8 per group). Rat anti-mouse IL-17A treatment obviously reduced plaque size by 43% (p<0.01) without evidence of reduced IL-17A signaling. In contrast, mouse anti-mouse IL-17A treatment and IL-17A deficiency in bone marrow cells did not alter lesion size despite significant reduction of IL-17A production., Conclusions: Inhibition of IL-17A signaling does not alter lesion development in Th1-biased C57BL/6 ApoE(-/-) and Ldlr(-/-) mice with already low levels of IL-17A production. Alteration of lesion development after repeated injections of rat anti-mouse IL-17A antibody in ApoE(-/-) mice could not be attributed to blockade of IL-17A signaling., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Objective: Atherosclerosis is a chronic inflammatory disease in which the renin-angiotensin-aldosterone system plays an important role. Evidence indicate that the angiotensin type 1 receptor blockers can suppress atherogenesis, but the exact mechanisms have not been fully elucidated. The study was undertaken to investigate the potential effects and molecular mechanisms of an angiotensin type 1 receptor blocker irbesartan on atherogenesis in high cholesterol-diet apolipoprotein E knock-out mice., Methods and Results: Adult male apolipoprotein E knock-out mice were given normal diet or high cholesterol-diet and randomized to receive no treatment or irbesartan 10 mg kg(-1) d(-1) for 12 weeks. The apolipoprotein E knock-out mice with high cholesterol-diet were associated with a marked increase in atherosclerotic lesion area, plasma lipid and angiotensin II levels, as well as the expressions of angiotensin type 1 receptor in the aorta. High cholesterol-diet feeding increases the activity of NADPH oxidase subunits (p47(phox) and Rac), extracellular signal-regulated kinase 1/2, janus kinase 2, signal transducer and activator of transcription 3, nuclear factor-kappaB and the expression of tumor necrosis factor-alpha, interleukin 6, monocyte chemoattactant protein-1 and vascular cell adhesion molecule-1 in the aortas. These changes were suppressed in mice that were treated with irbesartan 10 mg kg(-1) d(-1), with no significant change in systolic blood pressure and plasma lipid levels., Conclusions: The results suggest that irbesartan can attenuate atherosclerosis, and this effect is partly related to the inhibition of oxidative stress and inflammatory signal transduction pathways which eventually leads to the decrease in the expression of inflammatory cytokines., (Copyright 2008 Elsevier Ireland Ltd. All rights reserved.)

Objective: Atherosclerosis is a chronic inflammatory disease regulated by T lymphocyte subsets. Recently, CD4(+) CD25(+) Foxp3(+) regulatory T (Treg) cells and Th17 cells have been described as two distinct subsets and have the opposite effects on autoimmunity. Clinical observation has revealed that the Th17/Treg imbalance exists in patients with acute coronary syndrome. We investigated whether the Th17/Treg functional imbalance existed during atherogenesis in ApoE(-/-) mice., Methods and Results: Th17/Treg functions at different levels including cell frequencies, related cytokine secretion and key transcription factors were investigated comparatively between ApoE(-/-) mice and their age-matched C57BL/6J mice. The results demonstrated that ApoE(-/-) mice revealed significantly increased secretion of Th17 related cytokines (IL-17 and IL-6) and expression of transcription factor (RORgammat) levels and obviously decreased number in Treg cells, secretion of Treg related cytokines (TGF-beta(1)) and expression of transcription factor (Foxp3) levels as compared with age-matched C57BL/6J mice. Th17 related mediators reached their maximum expression values at the early stage (8-16weeks of age) in ApoE(-/-) mice, and then followed by continuous depression of their expression levels. Meanwhile, the expression of Treg related mediators was much lower in ApoE(-/-) mice than in their age-matched wild-type littermates., Conclusions: Th17/Treg functional imbalance exists during atherogenesis in ApoE(-/-) mice, suggesting a potential role of Th17/Treg imbalance in the formation and progression of atherosclerosis., (Copyright 2009 Elsevier Ltd. All rights reserved.)

Aim: Hyperhomocysteinemia (Hhcy) is an important and independent risk factor for atherosclerosis. Recent studies have shown that Poly (ADP-ribose) polymerase (PARP) activation may be associated with Hhcy-induced endothelial dysfunction, which is an important mechanism for Hhcy to affect atherosclerotic progress. Thus, we investigated whether PARP inhibitors may attenuate atheroscle-rotic plaque development in an Hhcy-induced experimental animal model with atherosclerosis., Methods: Six-week-old homozygous apolipoprotein E-deficient (ApoE-/-) male mice fed a normal diet or high methionine diet randomly received intraperitoneal injections of 10 mg/kg 3-aminoben-zamide (3-AB, a PARP inhibitor) dissolved in phosphate-buffered saline (PBS), or physiological saline every other day for 12 weeks. Atherosclerotic lesion sizes and PARP activity were measured. Related inflammatory factors in atherogenesis were investigated by real-time quantitative PCR and Western blot analysis., Results: Our data demonstrated that ApoE-/- mice fed a high methionine diet generated Hhcy, which subsequently increased the atherosclerotic lesion size significantly, promoted oxidative stress-associated DNA damage and PARP activation, then increased the expression of proinflammatory fac-tors within atherosclerotic plaques. Although PARP inhibition by 3-AB did not markedly inhibit plaque development in ApoE-/- mice with spontaneous hyperlipidemia by feeding a normal diet, it significantly reduced the atherosclerotic lesion size by 40% in Hhcy-induced atherosclerosis without affecting plasma homocysteine levels and lipid contents, effectively suppressed PARP activation, and inhibited nuclear translocation of nuclear factor-(kappa)B (NF-(kappa)B) and subsequent production of inflam-matory factors, such as vascular cell adhesion molecule-1 (VCAM-1) and monocyte chemoattactant protein-1 (MCP-1)., Conclusion: Our results suggest that PARP inhibition attenuates atherosclerotic plaque development under hyperhomocysteinemic conditions, through the inhibition of PARP activation, nuclear NF-kappaB translocation and subsequent expression of inflammatory factors.

Atherosclerosis is a chronic inflammatory disease, which is positively and negatively regulated by T helper (Th) 1 and Th2 lymphocytes, respectively. Recent findings indicate that suppressive oligodeoxynucleotides (ODNs) expressing TTAGGG motifs selectively reduce Th1 cytokine production and have been proven effective at blocking the development of organ-specific autoimmune diseases. In the current research, we hypothesized that suppressive ODNs may alter the development of atherosclerosis. Eight-week-old homozygous ApoE(-/-) male mice were injected with 300 mug ODNs A151 (TTAGGG) or nonspecific ODNs 1612. Atherosclerotic lesion sizes were dramatically reduced by ODNs A151, but not by nonspecific ODNs. MCP-1 and VCAM-1, which are the key inflammatory factors in atherogenesis, were significantly attenuated by the suppressive ODNs A151. In the splenic lymphocytes, FACS analysis showed ODNs A151 reduced the percentage of IFN-gamma-producing Th1 cells and slightly increased the percentage of IL-4-producing Th2 cells, indicating that suppressive ODNs skewed the Th1/Th2 balance toward Th2 inflammation in vivo. Furthermore, ODNs A151 down-regulated the phosphorylation of STAT1 and STAT4 and suppressed up-regulation of T-bet, a signal modulator for Th1, and didn't impact GATA-3 and STAT6, which are associated with a Th2 phenotype. Consistent with this in vivo observation, ELISA analysis demonstrated that ODNs A151 suppressed Th1 cytokines IFN-gamma and TNF-alpha, and augmented Th2 cytokines IL-4 and IL-10 in vitro. This study provides the first experimental evidence that suppressive ODNs inhibit the development of atherosclerosis through inhibition of the STAT1/4 and T-bet pathways, which further modulate the Th1/Th2 balance in vivo.

Oxidative stress and inflammation processes are key components of atherosclerosis, from fatty streak formation to plaque rupture and thrombosis. Evidence has revealed that calcium-channel blockers (CCB) could retard atherogenesis, but the exact mechanisms have not been fully elucidated. The present study was undertaken to investigate the potential effects and molecular mechanisms of the CCB felodipine on the process of atherosclerosis in high-cholesterol-diet (HCD) apolipoprotein E-knockout (ApoE KO) mice. Adult male ApoE KO mice were given a normal diet (ND) or HCD and were randomized to no treatment or felodipine (5 mg / kg per day for 12 weeks). The ApoE KO mice with HCD were associated with a marked increase in plasma lipid levels, atherosclerotic lesion area, and the expressions of NADPH oxidase subunits (p47 and Rac-1), nuclear factor-kappaB (NF-kappaB) in nucleus, phosphor-inhibitors of kappaB (p-IkappaB), tumor necrosis-alpha (TNF-alpha), monocyte chemoattractant protein-1 (MCP-1), and vascular cell-adhesion molecule-1 (VCAM-1). These changes were suppressed in mice that were treated with felodipine (5 mg/kg per day for 12 weeks) concomitant with HCD administration, with no significant change in systolic blood pressure and plasma lipid levels. The results suggest that felodipine can attenuate atherosclerosis, and this effect is partly related to inhibition of oxidative stress and inflammatory signal-transduction pathways, which lead to decreases in the expression of inflammatory cytokines.

Purpose: It has been established that obstructive sleep apnea (OSA) is an independent risk factor for atherosclerosis. Chronic intermittent hypoxia (CIH) activates sympathoadrenal system and upregulates β3 adrenergic receptor (β3 AR). However, the effect of selective β3 AR agonist mirabegron in CIH-induced atherosclerosis remains unknown. Methods: We generated a CIH-induced atherosclerosis model through exposing ApoE−/− mice to CIH (8 h per day, cyclic inspiratory oxygen fraction 5–21%, 60-s cycle) for 6 weeks after 4-week high-fat dieting and investigated the effects of mirabegron, a selective β3 AR agonist, on CIH-induced atherosclerosis. The coronary endarterectomy (CE) specimens from coronary artery disease patients with OSA and without OSA were collected. Results: The expression of β3 AR was significantly elevated in CIH-induced atherosclerosis model. Furthermore, treatment with mirabegron (10mg/kg per day by oral administration for 6 weeks) ameliorated atherosclerosis in ApoE−/− mice in CIH but not in normoxia. Mechanistically, mirabegron activated β3 AR and ameliorated intraplaque oxidative stress by suppressing p22phox expression and reactive oxygen species (ROS) level. In addition, in human CE specimens, β3 AR was also upregulated associated with increased p22phox expression and ROS level both in the lumen and in the plaque of coronary artery in OSA subjects. Conclusion: This study first demonstrated that mirabegron impeded the progression of CIH-induced atherosclerosis, at least in part, via β3 AR–mediated oxidative stress, suggesting a promising therapeutic strategy for protecting against atherosclerosis induced by CIH. [ABSTRACT FROM AUTHOR]

Abstract: Objective: Atherosclerosis is a chronic inflammatory disease regulated by T lymphocyte subsets. Recently, CD4+ CD25+ Foxp3+ regulatory T (Treg) cells and Th17 cells have been described as two distinct subsets and have the opposite effects on autoimmunity. Clinical observation has revealed that the Th17/Treg imbalance exists in patients with acute coronary syndrome. We investigated whether the Th17/Treg functional imbalance existed during atherogenesis in ApoE−/− mice. Methods and results: Th17/Treg functions at different levels including cell frequencies, related cytokine secretion and key transcription factors were investigated comparatively between ApoE−/− mice and their age-matched C57BL/6J mice. The results demonstrated that ApoE−/− mice revealed significantly increased secretion of Th17 related cytokines (IL-17 and IL-6) and expression of transcription factor (RORγt) levels and obviously decreased number in Treg cells, secretion of Treg related cytokines (TGF-β1) and expression of transcription factor (Foxp3) levels as compared with age-matched C57BL/6J mice. Th17 related mediators reached their maximum expression values at the early stage (8–16weeks of age) in ApoE−/− mice, and then followed by continuous depression of their expression levels. Meanwhile, the expression of Treg related mediators was much lower in ApoE−/− mice than in their age-matched wild-type littermates. Conclusions: Th17/Treg functional imbalance exists during atherogenesis in ApoE−/− mice, suggesting a potential role of Th17/Treg imbalance in the formation and progression of atherosclerosis. [Copyright &y& Elsevier]

Abstract: Atherosclerosis is a chronic inflammatory disease, which is positively and negatively regulated by T helper (Th) 1 and Th2 lymphocytes, respectively. Recent findings indicate that suppressive oligodeoxynucleotides (ODNs) expressing TTAGGG motifs selectively reduce Th1 cytokine production and have been proven effective at blocking the development of organ-specific autoimmune diseases. In the current research, we hypothesized that suppressive ODNs may alter the development of atherosclerosis. Eight-week-old homozygous ApoE−/− male mice were injected with 300 μg ODNs A151 (TTAGGG) or nonspecific ODNs 1612. Atherosclerotic lesion sizes were dramatically reduced by ODNs A151, but not by nonspecific ODNs. MCP-1 and VCAM-1, which are the key inflammatory factors in atherogenesis, were significantly attenuated by the suppressive ODNs A151. In the splenic lymphocytes, FACS analysis showed ODNs A151 reduced the percentage of IFN-γ-producing Th1 cells and slightly increased the percentage of IL-4-producing Th2 cells, indicating that suppressive ODNs skewed the Th1/Th2 balance toward Th2 inflammation in vivo. Furthermore, ODNs A151 down-regulated the phosphorylation of STAT1 and STAT4 and suppressed up-regulation of T-bet, a signal modulator for Th1, and didn''t impact GATA-3 and STAT6, which are associated with a Th2 phenotype. Consistent with this in vivo observation, ELISA analysis demonstrated that ODNs A151 suppressed Th1 cytokines IFN-γ and TNF-α, and augmented Th2 cytokines IL-4 and IL-10 in vitro. This study provides the first experimental evidence that suppressive ODNs inhibit the development of atherosclerosis through inhibition of the STAT1/4 and T-bet pathways, which further modulate the Th1/Th2 balance in vivo. [Copyright &y& Elsevier]

Abstract: Atherosclerosis is a chronic inflammatory disease regulated by T lymphocyte subsets. Recently, CD4+CD25+Foxp3+ regulatory T (Treg) cells and Th17 cells have been described as two distinct subsets from Th1 and Th2 cells and have the opposite effects on autoimmunity. Th17/Treg balance controls inflammation and may be important in the pathogenesis of plaque destabilization and the onset of acute coronary syndrome [ACS, including unstable angina (UA) and acute myocardial infarction (AMI)]. To assess whether this balance was broken in patients with coronary heart disease, we detected Th17/Treg functions on different levels including cell frequencies, related cytokine secretion and key transcription factors in patients with AMI, UA, stable angina (SA) and controls. The results demonstrated that patients with ACS revealed significant increase in peripheral Th17 number, Th17 related cytokines (IL-17, IL-6 and IL-23) and transcription factor (RORγt) levels and obvious decrease in Treg number, Treg related cytokines (IL-10 and TGF-β1) and transcription factor (Foxp3) levels as compared with patients with SA and controls. Results indicate that Th17/Treg functional imbalance exists in patients with ACS, suggesting a potential role for Th17/Treg imbalance in plaque destabilization and the onset of ACS. [Copyright &y& Elsevier]