Suppression of cortical TRPM7 protein attenuates oxidative damage after traumatic brain injury via Akt/endothelial nitric oxide synthase pathway.

Neuronal death after traumatic brain injury (TBI) is a complex process resulting from a combination of factors, many of which are still unknown. Transient receptor potential melastatin 7 (TRPM7) is a transient receptor potential channel that has been demonstrated to mediate ischemic and traumatic neuronal injury in vitro. In the present study, TRPM7 was suppressed in the rat cerebral cortex by intracortical injections of viral vectors bearing shRNA specific for TRPM7 to investigate its potential role in an in vivo TBI model. We found that TRPM7 suppression significantly reduced brain edema, brain contusion volume and motor functional deficits, which was sustained for at least 2 weeks after the insult. These protective effects were accompanied by inhibited apoptosis in injured cortex. Also, TRPM7 suppression attenuated lipid peroxidation, decreased the expression of protein carbonyl, and preserved the endogenous antioxidant enzyme activities. The results of western blot analysis showed that TRPM7 suppression markedly increased the phosphorylation of Akt and endothelial nitric oxide synthase (eNOS). In addition, blocking Akt/eNOS pathway activation by the specific inhibitor LY294002 (LY, 10 µL, 10 mmol/L) or L-NIO (0.5 mg/kg) partially reversed the protective effects of TRPM7 suppression and its anti-oxidative activities. Taken together, these findings demonstrated that regional inhibition of TRPM7 in cerebral cortex exerts neuroprotective effects against TBI through activation of Akt/eNOS pathway. Thus, TRPM7 might represent a potential drug development target for the treatment of TBI.

AEG-1 is associated with clinical outcome in neuroblastoma patients.

Astrocyte elevated gene 1 (AEG-1), a novel gene that was cloned in 2002, has emerged in recent years as a potentially crucial mediator of tumor malignancy and aberrant elevation of AEG-1 expression frequently occurs in several human cancers, including breast cancer, prostate cancer, gastric cancer. However, whether AEG-1 deregulation also occurs in neuroblastoma remains unclear. In previous study we reported that AEG-1 was over expressed in neuroblastoma cell lines and knockdown of AEG-1 inhibits proliferation and enhancing chemo-sensitivity to cisplatin or doxorubicin in neuroblastoma cells. In this study, we investigated the expression of AEG-1 and evaluate its prognostic significance by correlating AEG-1 expression levels with clinic pathologic features and survival in 32 archived neuroblastoma patients We found that positive AEG-1 immunoreactivities were present in all neuroblastoma cases, 75% showed high expression of AEG-1. And high expression of AEG-1 was commonly seen in vascular endothelial cells and glandula in neuroblastoma samples. AEG-1 expression was strongly correlated with age at diagnosis (P=0.012), clinical stage (P=0.030) and tumor histology stage (P=0.041). However, our analyses did not show significant associations between AEG-1 expression and other clinical features including gender and primary tumor site. Importantly, our data presented in this report provide, for the first time, evidence that elevated expression of AEG-1 protein is correlated with poor prognosis and reduced survival of patients with neuroblastoma (P= 0.031). Overall, the data support the notion that AEG-1 might be used as a biomarker for neuroblastoma patients.

Meta analysis on the relationship between gene polymorphisms of vascular endothelial growth factor and retinal prognosis risk of prematurity.

AIM: To explore the relationship between gene polymorphisms of vascular endothelial growth factor (VEGF) and retinopathy of prematurity (ROP). METHODS: Literature materials related to gene polymorphisms of VEGF and ROP in PubMed, EMBASE, Cochrane and CBM database were retrieved. These materials were screened according to inclusion and exclusion standards. Patients diagnosed with ROP in clinic were regarded as control group and ROP patients who were in treatment were regarded as observation group. The indexes in two groups were matched except birth weight (BW), gender and gestational weeks. Meta5.1 was used to analyze the relationship between gene polymorphisms of VEGF and ROP. RESULTS: Four random control tests (RCT) were included in this research, including 2611 patients. Meta analysis results showed that VEGF affected ROP, having statistical significance. The combined ratio was 0.44 (95%CI, 0.07, 0.80), 0.42 (95%CI, 0.09, 0.74) and 0.75 (95%CI, 0.02, 1.49), respectively. Carrying +405 allele might increase the premature infants' risk of having ROP. CONCLUSION: ROP may be related to its carrying of +405 allele. Large-scale, multi-factor RCT researches are still needed in order to identify the relation between VEGF and ROP.

Effects of metformin on the expression of GLUT4 in endometrium of obese women with polycystic ovary syndrome.

The objective was to explore the effects of metformin on the expression of endometrial glucose transporter 4 (GLUT4) and analyze the related factors of GLUT4 in patients with polycystic ovary syndrome (PCOS). This study included 20 obese patients with PCOS (PCOS group) and 20 obese patients who had infertility caused by oviducal or pelvic factors but had no PCOS (control group). Follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol-2 (E(2)), testosterone (T), fasting serum glucose (FSG), fasting insulin serum (FINS), homeostasis model assessment-insulin resistance (HOMA-IR), and endometrial GLUT4 expression were determined in the two groups. In PCOS group, patients were given 500 mg of metformin three times per day for 3 mo, and then the parameters above were determined again and compared with that before metformin treatment. The parameters above also were compared between PCOS and control groups. The correlation of GLUT4 with its related factors was analyzed. The levels of T, FINS, and HOMA-IR were higher in PCOS group than in the control group (P < 0.01). The levels of protein and mRNA of endometrial GLUT4 were lower in the PCOS group than in the control group (P < 0.001). The expression of protein and mRNA of endometrial GLUT4 increased after metformin treatment (P < 0.001). HOMA-IR was negatively correlated with GLUT4 expression (P = 0.027). In patients with PCOS, the levels of protein and mRNA of endometrial GLUT4 were lower compared with that in non-PCOS women, and HOMA-IR was strongly associated with endometrial GLUT4 expression. Metformin may up-regulate endometrial GLUT4 expression to improve endometrial IR.

Angiotensin-converting enzyme-2 overexpression improves left ventricular remodeling and function in a rat model of diabetic cardiomyopathy.

OBJECTIVES: The aim of this study was to test the hypothesis that angiotensin (Ang)-converting enzyme-2 (ACE2) overexpression may inhibit myocardial collagen accumulation and improve left ventricular (LV) remodeling and function in diabetic cardiomyopathy. BACKGROUND: Hyperglycemia activates the renin-Ang system, which promotes the accumulation of extracellular matrix and progression of cardiac remodeling and dysfunction. METHODS: Ninety male Wistar rats were divided randomly into treatment (n = 80) and control (n = 10) groups. Diabetes was induced in the treatment group by a single intraperitoneal injection of streptozotocin. Twelve weeks after streptozotocin injection, rats in the treatment group were further divided into adenovirus-ACE2, adenovirus-enhanced green fluorescent protein, losartan, and mock groups (n = 20 each). LV volume; LV systolic and diastolic function; extent of myocardial fibrosis; protein expression levels of ACE2, Ang-converting enzyme, and Ang-(1-7); and matrix metalloproteinase-2 activity were evaluated. Cardiac myocyte and fibroblast culture was performed to assess Ang-II and collagen protein expression before and after ACE2 gene transfection. RESULTS: Four weeks after ACE2 gene transfer, the adenovirus-ACE2 group showed increased ACE2 expression, matrix metalloproteinase-2 activity, and LV ejection fractions and decreased LV volumes, myocardial fibrosis, and ACE, Ang-II, and collagen expression in comparison with the adenovirus-enhanced green fluorescent protein and control groups. ACE2 was superior to losartan in improving LV remodeling and function and reducing collagen expression. The putative mechanisms may involve a shift in balance toward an inhibited fibroblast-myocyte cross-talk for collagen and transforming growth factor-beta production and enhanced collagen degradation by matrix metalloproteinase-2. CONCLUSIONS: ACE2 inhibits myocardial collagen accumulation and improves LV remodeling and function in a rat model of diabetic cardiomyopathy. Thus, ACE2 provides a promising approach to the treatment of patients with diabetic cardiomyopathy.

Combination of fluvastatin and losartan relieves atherosclerosis and macrophage infiltration in atherosclerotic plaques in rabbits.

AIM: To investigate whether the combination of fluvastatin and losartan synergistically relieve atherosclerosis and plaque inflammation induced by a high-cholesterol diet in rabbits. METHODS: Atherosclerosis was induced with a high-cholesterol diet for 3 months in 36 New Zealand white rabbits. The animals were randomly divided into model group, fluvastatin (10 mg·kg(-1)·d(-1)) group, losartan (25 mg·kg(-1)·d(-1)) group, and fluvastatin plus losartan group. After the 16-week treatments, the blood samples the animals were collected, and the thoracic aortas were examined immunohistochemically. The mRNA and protein expression levels of monocyte chemotactic protein-1 (MCP-1) were measured using RT-PCR and Western blot. RESULTS: Compared to the treatment with losartan or fluvastatin alone, the combined treatment did not produce higher efficacy in reduction of blood cholesterol level. However, the combination did synergistically decrease the intimal and media thickness of thoracic aortas with significantly reduced macrophage infiltration and MCP-1 expression in the plaques. CONCLUSION: The combined treatment with losartan and fluvastatin significantly inhibited atherosclerotic progress and reduced inflammation associated with atherosclerotic plaques.

Angiotensin-converting enzyme (ACE) 2 overexpression ameliorates glomerular injury in a rat model of diabetic nephropathy: a comparison with ACE inhibition.

The reduced expression of angiotensin-converting enzyme (ACE) 2 in the kidneys of animal models and patients with diabetes suggests ACE2 involvement in diabetic nephrology. To explore the renoprotective effects of ACE2 overexpression, ACE inhibition (ACEI) or both on diabetic nephropathy and the potential mechanisms involved, 50 Wistar rats were randomly divided into a normal group that received an injection of sodium citrate buffer and a diabetic model group that received an injection of 60 mg/kg streptozotocin. Eight wks after streptozotocin injection, the diabetic rats were divided into no treatment group, adenoviral (Ad)-ACE2 group, Ad-green flurescent protein (GFP) group, ACEI group receiving benazepril and Ad-ACE2 + ACEI group. Four wks after treatment, physical, biochemical, and renal functional and morphological parameters were measured. An experiment in cultured glomerular mesangial cells was performed to examine the effects of ACE2 on cellular proliferation, oxidative stress and collagen IV synthesis. In comparison with the Ad-GFP group, the Ad-ACE2 group exhibited reduced systolic blood pressure, urinary albumin excretion, creatinine clearance, glomeruli sclerosis index and renal malondialdehyde level; downregulated transforming growth factor (TGF)-ß1, vascular endothelial growth factor (VEGF) and collagen IV protein expression; and increased renal superoxide dismutase activity. Ad-ACE2 and ACEI had similar effects, whereas combined use of Ad-ACE2 and ACEI offered no additional benefits. ACE2 transfection attenuated angiotensin (Ang) II-induced glomerular mesangial cell proliferation, oxidative stress and collagen IV protein synthesis. In conclusion, ACE2 exerts a renoprotective effect similar to that of ACEI treatment. Decreased renal Ang II, increased renal Ang-(1-7) levels, and inhibited oxidative stress were the possible mechanisms involved.

Combinatorial interference of toll-like receptor 2 and 4 synergistically stabilizes atherosclerotic plaque in apolipoprotein E-knockout mice.

To test the hypothesis that combinatorial interference of toll-like receptor 2 (TLR2) and TLR4 is superior to isolated interference of TLR2 or TLR4 in stabilizing atherosclerotic plaques, lentiviruses carrying small interfering RNA of TLR2 or TLR4 were constructed and proved efficacious for knocking down mRNA and protein expression of TLR2 or TLR4 significantly in vitro. One hundred and fifty apolipoprotein E(-/-) mice fed a high-fat diet were divided into the control, mock, TLR2i, TLR4i and TLR2 + 4i subgroups and a constrictive collar was placed around carotid artery of these mice to induce plaque formation. TLR2i and TLR4i viral suspension was transfected into carotid plaques, respectively, in TLR2i and TLR4i subgroups, or in combination in TLR2 + 4i subgroup. Four weeks after lentivirus transfection, mRNA and protein expression of TLR2 or TLR4 was attenuated markedly in carotid plaques, leading to reduced local inflammatory cytokine expression and plaque content of lipid and macrophages, increased plaque content of collagen and lowered plaque vulnerability index. Factorial ANOVA analysis revealed that there was a synergistic effect between TLR4i and TLR2i in stabilizing plaques. In conclusion, combinatorial interference of TLR2 and TLR4 reduces local inflammation and stabilizes plaques more effectively than interference of TLR2 or TLR4 alone.

Atherosclerotic plaque components characterization and macrophage infiltration identification by intravascular ultrasound elastography based on b-mode analysis: validation in vivo.

Intravascular ultrasound elastography (IVUSE) is a promising imaging technique for early investigation of vulnerable plaques. Compared to radiofrequency signal processing, digital B-mode analysis is simple and of higher portability. However, rare studies have been reported validating the latter technique in vivo. In this study, we developed an IVUSE computer software system involving semi-automatic border delineation and block-matching algorithm and validated the system in vivo. Seven minipigs were fed with atherogenic diet for 40 weeks. For each pig, the endothelium of one side of the renal arteries was denuded at the fifth week. With cross-correlation analysis, Lagrangian strain was calculated from two intravascular ultrasound images acquired in situ. Sixty regions of interests were selected from 35 elastograms matched well with the corresponding histological slices. Plaque types within these regions were classified as fibrous, fibro-fatty or fatty on Masson's trichrome and Oil-red O staining. Macrophage infiltration was also evaluated with immunohistology. Comparison between the mean strain value of the region of interest and the histological results revealed significant differences in strain values among different plaque types and non-diseased artery walls. The extent of macrophage infiltration was found to be correlated positively with strain values. For identification of fibro-fatty and fibrous plaques and macrophage infiltration, the system showed high sensitivity (93, 96 and 92%, respectively) and specificity (89, 76 and 66%, respectively), as revealed by receiver operating characteristic analysis. Our IVUSE system based on B-mode analysis is capable of characterizing fibrous and fibro-fatty plaques and macrophage intensity, thus holds potential for identifying vulnerable plaque.

Angiotensin-converting enzyme 2 attenuates atherosclerotic lesions by targeting vascular cells.

Angiotensin-converting enzyme 2 (ACE2) is a newly discovered homolog of ACE whose actions oppose those of angiotensin II (AngII). However, the underlying mechanisms by which ACE2 effectively suppresses early atherosclerotic lesions remain poorly understood. Here, we show, both in vitro and in vivo, that ACE2 inhibited the development of early atherosclerotic lesions by suppressing the growth of vascular smooth muscle cells (VSMCs) and improving endothelial function. In a relatively large cohort animal study (66 rabbits), aortic segments transfected by Ad-ACE2 showed significantly attenuated fatty streak formation, neointimal macrophage infiltration, and alleviation of impaired endothelial function. Segments also showed decreased expression of monocyte chemoattractant protein 1, lectin-like oxidized low-density lipoprotein receptor 1, and proliferating cell nuclear antigen, which led to the delayed onset of atherosclerotic lesions. At the cellular level, ACE2 significantly modulated AngII-induced growth and migration in human umbilical vein endothelial cells and VSMCs. The antiatherosclerotic effect of ACE2 involved down-regulation of the ERK-p38, JAK-STAT, and AngII-ROS-NF-kappaB signaling pathways and up-regulation of the PI3K-Akt pathway. These findings revealed the molecular mechanisms of the antiatherosclerotic activity of ACE2 and suggested that modulation of ACE2 could offer a therapeutic option for treating atherosclerosis.

Gax gene transfer inhibits vascular remodeling induced by adventitial inflammation in rabbits.

AIMS: Adventitial fibroblasts (AFs) and inflammation play an important role in neointimal formation and vascular remodeling. The present study was aimed to investigate the therapeutic effects and underlying mechanisms of transcriptional regulator Gax gene transfection in aortic remodeling induced by adventitial inflammation. METHODS AND RESULTS: Fifty rabbits fed a chow diet were randomly divided into a normal control group (n=10) and experimental group (n=40). All rabbits in the experimental group underwent collar placement around the abdominal aorta and intra-collar injection of lipopolysaccharide (LPS) to induce adventitial inflammation and they were further divided into model control group, saline-treated group, green fluorescence protein (Ad-GFP)-treated group and Gax gene (Ad-Gax)-treated group, respectively. Four weeks after treatment, the model control group, saline-treated group and Ad-GFP-treated group showed thickened neointima and adventitia, reduced lumen size and increased eccentricity and remodeling index of the abdominal aorta in comparison with the normal control group, whereas Ad-Gax-treated group exhibited attenuated neointimal formation and vascular remodeling (P<0.01-0.05) .The vascular expression levels of interleukin (IL)-1ß, IL-6, IL-8, monocyte chemoattractant protein (MCP)-1, matrix metalloproteinase (MMP)-1, MMP-2, MMP-9, vascular cell adhesion molecule (VCAM)-1 and intercellular adhesion molecule (ICAM)-1, Smads, mitogen-activated protein kinases (MAPKs), integrins and nuclear factor kappa B (NF-kB) were significantly higher in the model control group, saline-treated group and Ad-GFP-treated group than those in the normal control group (P<0.01-0.05). In contrast, the local expression levels of these cytokines were substantially reduced by Ad-Gax gene transfer (P<0.01-0.05). Similarly, the serum levels of inflammatory cytokines including C-reactive protein (CRP), transforming growth factor (TGF)-ß1, IL-1, IL-6, IL-8, tumor necrosis factor (TNF)-α, MCP-1, VCAM-1 and ICAM-1 were significantly higher in the model control group, saline-treated group and Ad-GFP-treated group than those of the Ad-Gax-treated group (P<0.01-0.05). In vitro studies showed that Gax overexpression diminished inflammatory cytokine expression in LPS-stimulated arterial fibroblasts. CONCLUSIONS: Adventitial inflammation induces vascular remodeling via the interactions of multiple inflammatory cytokines and local Gax gene transfer in vivo can significantly inhibit these interactions and thereby attenuate local inflammation and vascular remodeling.

Haemin-enhanced expression of haem oxygenase-1 stabilizes erythrocyte-induced vulnerable atherosclerotic plaques.

BACKGROUND AND PURPOSE: Previous studies demonstrated that intraplaque haemorrhage increased the contents of cholesterol and oxidants in atherosclerotic plaques. The present study was aimed to test the hypothesis that enhanced expression of haem oxygenase-1 (HO-1) may stabilize vulnerable plaques. EXPERIMENTAL APPROACH: Intravascular ultrasound (IVUS) was performed to identify three similar abdominal aortic plaques in each of 58 fat-fed New Zealand rabbits after aortic balloon injury. With the guidance of IVUS, 50 microL autologous erythrocytes (RBC) or normal saline (NS) were injected from adventitia into two of the pre-selected plaques, respectively, whereas the third plaque served as a blank control. All rabbits were randomly divided into two groups, receiving intraperitoneal injection of haemin and saline respectively. KEY RESULTS: Compared with NS or control plaques, RBC plaques had more macrophage infiltration and lipid content, thinner plaque fibrous cap, and higher expression of inflammatory factors and incidence of plaque rupture. RBC plaques in the haemin group had about a 50% lower incidence of plaque rupture than those in the control group. CONCLUSIONS AND IMPLICATIONS: Haem oxygenase-1 may eliminate haem or other oxidants, exert unexpected anti-oxidative and anti-inflammatory effects and serve as a promising approach to the direct inhibition of erythrocyte-induced plaque instability.

ACE2 overexpression ameliorates left ventricular remodeling and dysfunction in a rat model of myocardial infarction.

The purpose of this study was to test the hypothesis that overexpression of angiotensin-converting enzyme 2 (ACE2) may favorably affect left ventricular (LV) remodeling and function after myocardial infarction (MI). The left anterior descending coronary artery was ligated to produce anterior MI in 100 Wistar-Kyoto rats that were randomly divided into Ad-ACE2, Ad-ACE2+A779, Ad-EGFP, model, and sham groups. Two weeks later, rats in the Ad-ACE2 and Ad-EGFP groups received direct intramyocardial injection of Ad-ACE2 and Ad-EGFP, respectively. Rats in the Ad-ACE2+A779 group received both intramyocardial injection of Ad-ACE2 and a continuous intravenous infusion of A779 for 15 days. LV volume and systolic function, the extent of myocardial fibrosis, and levels of ACE2, angiotensin II (Ang II), and collagen I protein expression were evaluated. Four weeks after ACE2 gene transfer, the Ad-ACE2 group showed reduced LV volume, extent of myocardial fibrosis, and expression levels of ACE, Ang II, and collagen I in the myocardium, and increased LV ejection fraction and levels of ACE2 activity and expression in comparison with the Ad-EGFP and model groups. These results suggest that ACE2 overexpression attenuated LV fibrosis and improved LV remodeling and systolic function. In conclusion, overexpression of ACE2 favorably affected the pathological process of LV remodeling after MI by inhibiting ACE activity, reducing AngII levels, and up-regulating Ang-(1-7) expression, thus providing a potential therapeutic target in the treatment of heart failure.

A causal relationship between shear stress and atherosclerotic lesions in apolipoprotein E knockout mice assessed by ultrasound biomicroscopy.

The present study was undertaken to examine the hemodynamic state using the latest ultrasound biomicroscopy (UBM) technique and to investigate the effect of local shear stress on the development of atherosclerosis in the constrictive collar-treated carotid arteries of apolipoprotein E-deficient (apoE(-/-)) mice. Fifty-six male apoE(-/-) mice fed a high-lipid diet were divided into an interventional group (n = 48) and the control group (n = 8). Constrictive and nonconstrictive collars were placed around the carotid artery of the mice in the interventional group and the control group, respectively. The carotid lumen diameters and flow velocities were measured by UBM, and shear stress in the lesion region was calculated. Histopathology and electron microscopy were performed to observe the morphological changes in the carotid artery. In the region proximal to the constrictive collar, shear stress was significantly reduced 2 days after collar placement and remained low over time compared with the baseline level. In contrast, within the constrictive collar region, shear stress was increased significantly. Although endothelial permeability was enhanced in both regions, monocyte chemotaxis protein-1 (MCP-1) expression, macrophage infiltration, and atherosclerotic lesions were more prominent in the region proximal to the constrictive collar. Moreover, increased MCP-1 expression was observed as early as 2 days after constrictive collar placement, which preceded the morphological changes of the vessel wall. In conclusion, UBM offers a noninvasive and reliable technique for measuring shear stress in apoE(-/-) mice. Persistent low shear stress promotes endothelial permeability and enhances MCP-1 expression and macrophage recruitment, which were essential in the pathogenesis of atherosclerosis in apoE(-/-) mice.

Peak radial and circumferential strain measured by velocity vector imaging is a novel index for detecting vulnerable plaques in a rabbit model of atherosclerosis.

AIMS: To evaluate the reliability of velocity vector imaging (VVI) for detecting vulnerable plaques. METHODS AND RESULTS: After aortic balloon injury, 60 rabbits were fed a 1% cholesterol diet for 10 weeks and normal chow for another 6 weeks. Adenovirus containing p53 or lac Z was then injected into the aortic plaques and rabbits were divided into p53-treated group (n=20), lac Z-treated group (n=20) and blank control group (n=20). Peak longitudinal (LSp), radial (RSp) and circumferential (CSp) strain of plaques was measured using VVI at the end of week 18 before pharmacological triggering. Higher RSp and CSp and lower LSp were found in ruptured than those in non-ruptured plaques, and RSp, CSp and LSp correlated well with the fibrous cap thickness and plaque content of macrophages, smooth muscle cells and collagen (all p<0.01). A logistic regression model showed that both RSp (RR: 8.96, 95% CI: 5.3575-10.4857, p<0.001) and CSp (RR: 8.45, 95% CI: 5.9043-9.1043, p<0.001) were significant predictors of plaque rupture. RSp and CSp had a sensitivity of 88.0% and 88.6% and a specificity of 88.6% and 92.0% to predict plaque disruption, respectively. CONCLUSION: VVI offers a new and noninvasive technique for measuring the peak strain of atherosclerotic plaques and RSp and CSp are a novel index with a high sensitivity and specificity for detecting plaques vulnerable to rupture.

PPARgamma1-induced caveolin-1 enhances cholesterol efflux and attenuates atherosclerosis in apolipoprotein E-deficient mice.

OBJECTIVE: Caveolin-1 (Cav-1) may positively or negatively influence the development of atherosclerosis, depending on the cell type and the metabolic pathways regulated by this protein. We investigate the effects of Cav-1 on cholesterol efflux in RAW264.7 infected with AdPPARgamma1 and whether Cav-1 could attenuate established atherosclerotic lesions in PPARgamma1-treated apoE-deficient mice. METHODS AND RESULTS: Compared with AdGFP control, PPARgamma1 and Cav-1 were constitutively overexpressed in AdPPARgamma1-infected RAW264.7 cells, which stimulated cholesterol efflux to apolipoprotein A-I. Using a small interfering RNA approach (Cav-1-siRNA) we achieved an efficient and specific knockdown of caveolin-1 expression (80%), which resulted in a remarkable reduction of cholesterol efflux in RAW264.7 cells . Moreover, PPARgamma1-treated Cav-1-siRNA RAW264.7 cells showed more ability to stimulate cholesterol efflux than Cav-1-siRNA RAW264.7 cells, but far less than control-siRNA RAW264.7 cells and PPARgamma1-treated RAW264.7 cells. In addition, 40-week-old apoE-deficient mice fed a Western-type diet and infected for 4 weeks with AdPPARgamma1 showed induced Cav-1 expression in aortic vascular endothelial cells, smooth muscle cells and macrophages, as well as attenuated established atherosclerotic lesions. CONCLUSIONS: PPARgamma1 gene therapy could induce Cav-1 expression and enhance cholesterol efflux and attenuate atherosclerosis in apoE-deficient mice.

[Overexpression of angiotensin converting enzyme 2 inhibits inflammatory response of atherosclerotic plaques in hypercholesterolemic rabbits].

OBJECTIVE: Angiotensin converting enzyme 2 (ACE2) efficiently hydrolyses the potent vasoconstrictor angiotensin II to vasodilative angiotensin (1-7). We hypothesized that ACE2 overexpression may inhibit inflammation response in atherosclerotic plaque by degrading Ang II into Ang-(1-7). METHODS: Atherosclerosis (AS) plaques were induced in the abdominal aorta of 38 rabbits by endothelial injury and atherogenic diet for 3 months. Rabbits were then underwent injection of a recombinant adenovirus (2.5 x 10(9) pfu/ml) carrying a murine ACE2 gene (Ad-ACE2) through a catheter into the abdominal aortic segments rich in plaques (n = 19) or injection of a control vector Ad-EGFP (n = 19). One month later, all rabbits were sacrificed and plaques from aortic segments were analyzed. RESULTS: ACE2 expression in aortic tissues of the Ad-ACE2 group were confirmed by immunohistochemistry. Macrophage infiltration (13.6% +/- 4.2% vs. 23.6% +/- 6.9%, P < 0.01) and MCP-1 expression (13.2% +/- 0.4% vs. 25.0% +/- 7.4%, P < 0.01) were significantly reduced in Ad-ACE2 group compared to Ad-EGFP group. CONCLUSIONS: Overexpression of ACE2 inhibited atherosclerotic plaque inflammation response in hypercholesterolemic rabbits.

Traditional Chinese medication Tongxinluo dose-dependently enhances stability of vulnerable plaques: a comparison with a high-dose simvastatin therapy.

This study was carried out to test the hypothesis that Tongxinluo (TXL) as a Chinese herbal medicine enhances stability of vulnerable plaque dose dependently via lipid-lowering and anti-inflammation effects, similar to a high-dose simvastatin therapy. After abdominal aortic balloon injury, 75 rabbits were fed a 1% cholesterol diet for 10 wk and were then divided into five groups for 8-wk treatment: control group, low-dose TXL group, moderate-dose TXL group, high-dose TXL group, and high-dose simvastatin group. At the end of week 16, an adenovirus containing p53 was injected into the abdominal aortic plaques. Two weeks later, plaque rupture was induced by pharmacological triggering. The incidence of plaque rupture in all treatment groups (14.3%, 7.1%, 7.7%, and 7.1%) was significantly lower than that in control group (73.3%; P>0.01). TXL dose-dependently lowered serum lipid levels and inhibited systemic inflammation. Corrected acoustic intensity and fibrous cap thickness of the aortic plaques were significantly increased, whereas plaque area, plaque burden, vulnerable index, and expression of oxidized low-density lipoprotein (ox-LDL) receptor 1, matrix metalloproteinase 1 (MMP-1), MMP-3, tissue inhibitor of MMP 1, and NF-kappaB in plaques were markedly reduced in all treatment groups when compared with the control group. Similar to high-dose simvastatin group, high-dose TXL group exhibited a low serum level of low-density lipoprotein cholesterol and ox-LDL, a low expression level of systemic and local inflammatory factors and a low plaque vulnerability index, with no differences in the incidence of plaque rupture among all treatment groups. TXL dose-dependently enhances the stability of vulnerable plaques and prevents plaques from rupture. Simvastatin and TXL offer similar protection in terms of lipid-lowering, anti-inflammation, and antioxidation effects.