冠状动脉外膜炎症在动脉粥样硬化病灶形成中的作用

目的：探讨动脉外膜炎症诱发载脂蛋白E基因剔除（apoE-/-）小鼠冠状动脉粥样硬化病灶发生的机制。 方法： 取apoE-/-小鼠心脏做连续切片，选择冠状动脉外膜有炎性细胞浸润的3类部位代表粥样硬化病灶形成过程中的3个阶段：①未发现粥样硬化病灶；②有直接从主动脉延伸的病灶顶端和③成熟粥样硬化病灶的冠状动脉。分别采用HE染色、Movat染色、免疫组化和透射电镜方法鉴定3个病变阶段的冠状动脉外膜中炎细胞类型。 结果： ①未发现粥样硬化病灶；②有直接从主动脉延伸的病灶顶端和③成熟粥样硬化病灶的冠状动脉外膜分别以巨噬细胞、中性粒细胞和淋巴细胞浸润为主，其构成比分别为60.00%、57.65%和66.67%，各组构成比分别与其它两组比较均有显著差异（P<0.01）。 结论： 动脉外膜炎症可能是诱发动脉粥样硬化发生的早期事件之一，ApoE-/-小鼠冠状动脉粥样硬化病灶形成过程中，动脉外膜经历了一个从急性炎症到慢性炎症的过程。     

Infection with Toxoplasma gondii increases atherosclerotic lesion in ApoE-deficient mice

Toxoplasma gondii is an intracellular protozoan that elicits a potent inflammatory response during the acute phase of infection. Herein, we evaluate whether T. gondii infection alters the natural course of aortic lesions. ApoE knockout mice were infected with T. gondii, and at 5 weeks of infection, serum, feces, and liver cholesterol; aortic lesion size, cellularity, and inflammatory cytokines; and levels of serum nitrite and gamma interferon (IFN-gamma) were analyzed. Our results showed that serum cholesterol and atherogenic lipoproteins were reduced after T. gondii infection. The reduction of serum levels of total cholesterol and atherogenic lipoproteins was associated with increases in the aortic lesion area, numbers of inflammatory cells, and expression of monocyte chemoattractant protein 1 and inducible nitric oxide synthase mRNA in the site of lesions as well as elevated concentrations of IFN-gamma and nitrite in sera of T. gondii-infected animals. These results suggest that infection with T. gondii accelerates atherosclerotic development by stimulating the proinflammatory response and oxidative stress, thereby increasing the area of aortic lesion.     

CXCR7在动脉粥样硬化模型ApoE-/-小鼠的表达及阿托伐他汀的干预作用

 目的: 研究CXC趋化因子受体7(CXC chemokine receptor 7,CXCR7)在动脉粥样硬化模型载脂蛋白E基因敲除(ApoE^-/-)小鼠中的表达并探究阿托伐他汀的干预作用。方法: 8周龄ApoE^-/-雄性小鼠,随机分为正常对照组、高脂组与高脂+阿托伐他汀组,实验干预12周建立动脉粥样硬化模型;油红O及HE染色观察动脉粥样硬化病变,Western blot及免疫组化法检测动脉CXCR7的表达,Western blot检测动脉eNOS和Akt的表达。结果: (1)动脉油红O及HE染色示高脂组可见有明显粥样核心及纤维帽的显著斑块,高脂+阿托伐他汀组也可见斑块,但斑块负荷较模型组减轻,正常对照组未见明显斑块形成;(2)免疫组化示高脂组动脉细胞着色浅,CXCR7表达量少,高脂+阿托伐他汀组与高脂组比较,细胞着色增加,CXCR7表达量增加,正常对照组颗粒呈深棕黄色,示CXCR7大量表达;(3)Western blot结果示高脂组CXCR7、eNOS和Akt的表达较正常对照组降低,给予阿托伐他汀干预后CXCR7、eNOS和Akt的表达较高脂组增加,较正常对照组相比CXCR7、eNOS和Akt的表达下降,但磷酸化eNOS的水平未见差异。结论: 高脂血症可损伤血管内皮,促进动脉粥样硬化的发展,下调动脉CXCR7、eNOS和Akt的表达;阿托伐他汀可改善动脉粥样硬化,缓解ApoE^-/-小鼠动脉CXCR7、eNOS和Akt蛋白表达的下调。     

载脂蛋白E基因敲除小鼠冠状动脉内粥样硬化病灶的研究

目的：研究载脂蛋白E基因敲除( apoE-/-)小鼠冠状动脉内粥样硬化病灶的分布和组成；探讨病灶发生和发展的机理。方法：取60周龄和112周龄的apoE-/-小鼠心脏作连续切片，从冠状动脉在主动脉开口处连续追踪冠状动脉主干和心肌内冠状动脉小分支，行Movat特殊染色，寻找病灶。根据组织切片数计算病灶离冠状动脉开口处的距离和病灶的长度；根据病灶的长度将病灶分为大、中、小3类病灶；用图像分析仪测量血管口径；根据Movat染色结果观察病灶内组成成分。结果：在apoE-/-小鼠冠状动脉内发现从主动脉内直接延续的延伸病灶和在冠状动脉分支内形成的原位病灶；在60周龄和112周龄小鼠冠状动脉延伸病灶的发生率分别为60%和80%；有延伸病灶的冠状动脉外膜有大量炎性细胞浸润。每只apoE-/-小鼠均有原位病灶；原位病灶多发生在左室壁心肌内血管分支处和乳头肌附近；随着原位病灶增大，蛋白聚糖成分减少，细胞内外脂质成分增多；增大的原位病灶可堵塞小血管；在有原位病灶的冠状动脉外膜常可发现有增多的炎性细胞。112周龄apoE-/-小鼠大原位病灶多于60周龄小鼠 (P＜0.05)。结论：apoE-/-小鼠冠状动脉主干和心肌小分支内分别存在着延伸和原位的粥样硬化病灶，随着小鼠周龄增加，病灶增大。动脉外膜炎症和心肌收缩对血管的挤压与病灶的发生和发展有密切关系。     

Galectin-3 and Ki-67 expression in multiglandular parathyroid lesions

Hyperplastic and neoplastic parathyroid lesions may present overlapping morphologic features, and several markers have been proposed to distinguish benign from malignant growths. Recently, it was reported that galectin-3 is a useful marker of malignancy in uniglandular parathyroid diseases. To investigate galectin-3 and Ki-67 immunoexpression in parathyroid hyperplastic disease, 63 multiglandular lesions (13 primary, 40 secondary, and 10 tertiary hyperplasia cases) were analyzed and compared with 45 control cases of parathyroid adenomas and 24 carcinomas. Our data showed that hyperplastic lesions responsible for primary nonfamilial or tertiary hyperparathyroidism, as well as parathyroid adenomas, were negative for galectin-3, as opposed to carcinomas. In addition, secondary and familial primary hyperplasia cases were surprisingly positive for galectin-3 in approximately two thirds of cases. All hyperplastic lesions (positive or negative for galectin-3) had a low Ki-67 index. Based on these findings, secondary hyperplasia has a low proliferative potential but an unexplained galectin-3 reactivity, which reduces its diagnostic role in differentiating benign from malignant nodules in the context of multiglandular parathyroid diseases.     

Azithromycin increases survival and reduces lung inflammation in cystic fibrosis mice

Objective and design  Azithromycin (AZM) has been used as an anti-inflammatory agent in the treatment of cystic fibrosis (CF), particularly those with chronic infection with P. aeruginosa (PA). To investigate mechanisms associated with the beneficial effects of AZM in CF, we examined bacterial load, cytokine levels, and clearance of inflammatory cells in CF mice infected with mucoid PA and treated with AZM. Methods  Gut-corrected Cftr ^tm1Unc -TgN(FABPCFTR)#Jaw CF mice infected with an alginate-overproducing PA CF-isolate were treated with AZM or saline and examined for survival of animals, lung bacterial load, inflammation, cytokine levels, and apoptotic cells up to 5 days post-infection. Results  Administration of AZM (20 mg/kg) 24 h after the infection improved 5-day survival to 95% compared with treatment with saline (56%). AZM administration was associated with significant reductions in bacterial load, decreased lung inflammation, and increased levels of IFN-γ. AZM increased macrophage clearance of apoptotic neutrophils from the lung. Conclusion  Azithromycin enhances bacterial clearance and reduces lung inflammation by improving innate immune defense mechanisms in CF mice.     

Endothelial-specific expression of mitochondrial thioredoxin improves endothelial cell function and reduces atherosclerotic lesions

The function of the mitochondrial antioxidant system thioredoxin (Trx2) in vasculature is not understood. By using endothelial cell (EC)-specific transgenesis of the mitochondrial form of the thioredoxin gene in mice (Trx2 TG), we show the critical roles of Trx2 in regulating endothelium functions. Trx2 TG mice have increased total antioxidants, reduced oxidative stress, and increased nitric oxide (NO) levels in serum compared with their control littermates. Consistently, aortas from Trx2 TG mice show reduced vasoconstriction and enhanced vasodilation. By using ECs isolated from Trx2 TG mice, we further show that Trx2 increases the capacities of ECs in scavenging reactive oxygen species generated from mitochondria, resulting in increases in NO bioavailability in ECs. More importantly, Trx2 improves EC function and reduces atherosclerotic lesions in the apolipoprotein E-deficient mouse model. Our data provide the first evidence that Trx2 plays a critical role in preserving vascular EC function and prevention of atherosclerosis development, in part by reducing oxidative stress and increasing NO bioavailability.     

Chinese medicine Tongxinluo reduces atherosclerotic lesion by attenuating oxidative stress and inflammation in microvascular endothelial cells

Oxidative stress and inflammation are the important pathological basis of atherogenesis. So, attenuating oxidative stress and inflammation has a very important significance in the prevention and treatment of atherosclerosis. The aim of present study was to investigate whether anti-atherosclerotic effect of Tongxinluo (TXL), a compound traditional Chinese medicine, is related to its anti-oxidation and anti-inflammation in human cardiac microvascular endothelial cells (HCMEC). We found that TXL treatment significantly reduced serum lipid levels and atherosclerotic plaque formation of apoE-deficient mice, and improved endothelial cell function as evidenced by increased expression of CD31 and eNOS. TXL pretreatment could abrogate the up-regulation of ROS and MDA induced by C16. Further experiments showed that the anti-oxidative effect of TXL may be related to inhibiting the expression of p22^phox, p47^phox and HO-1 in HCMECs. We also found that TXL could inhibit the release of IL-1β and TNFα induced by C16, which is mediated by inhibiting the expression and activation of NF-κB. In conclusion, TXL decreases atherosclerotic plaque formation and improves endothelial cell function by inhibiting oxidative stress and inflammation in HCMECs. This finding provides a new molecular mechanism for the anti-atherosclerotic effect of TXL.     

Docosahexaenoic acid reduces inflammation and joint destruction in mice with collagen-induced arthritis

Objective

This study was designed to determine the anti-inflammatory activity of docosahexaenoic acid (DHA), alone and in combination with eicosapentaenoic acid (EPA), in a murine model of rheumatoid arthritis, collagen induced arthritis (CIA).

Methods

The CIA was induced in DBA/1OlaHsd mice by the injection of bovine type II collagen in Freunds’s complete adjuvant on days 0 and 21. Mice were fed modified diets containing DHA and/or EPA for 4 weeks prior to the initial collagen injection until study termination at day 45. The severity of CIA was assessed by measuring erythema, edema and mobility of the digits on the fore and hind paws, as well as histology. The level of serum anti-collagen antibodies was determined by ELISA. The ex vivo effects of DHA and/or EPA on splenocyte proliferation and cytokine production were evaluated by BrdU method and ELISA.

Results

Prophylactic treatment with DHA, and not DHA/EPA, significantly reduced arthritis severity and joint damage. Treatment with DHA also decreased anti-collagen (CII) antibodies in vivo, downregulated interleukin-1β, interferonγ and upregulated protective interleukin-10 ex vivo.

Conclusion

Prophylactic treatment with DHA was efficacious in a mouse model of rheumatoid arthritis and may be a useful intervention strategy against inflammatory arthritis.     

The UTX gene escapes X inactivation in mice and humans

We recently have identified a ubiquitously transcribed mouse Y chromosome gene, Uty , which encodes a tetratricopeptide repeat (TPR) protein. A peptide derived from the UTY protein confers H-Y antigenicity on male cells. Here we report the characterization of a widely transcribed X-linked homologue of Uty , called Utx , which maps to the proximal region of the mouse X chromosome and which detects a human X-linked homologue at Xp11.2. Given that Uty is ubiquitously transcribed, we assayed for Utx expression from the inactive X chromosome (Xi) in mice and found that Utx escapes X chromosome inactivation. Only Smcx and the pseudoautosomal Sts gene on the mouse X chromosome have been reported previously to escape inactivation. The human UTX gene was also found to be expressed from Xi. We discuss the significance of these data for our understanding of dosage compensation of X-Y homologous genes in humans and mice.      

Galectin-3 reduces the severity of pneumococcal pneumonia by augmenting neutrophil function

The Gram-positive Streptococcus pneumoniae is the leading cause of community-acquired pneumonia worldwide, resulting in high mortality. Our in vivo studies show that galectin-3(-/-) mice develop more severe pneumonia after infection with S. pneumoniae, as demonstrated by increased bacteremia and lung damage compared to wild-type mice and that galectin-3 reduces the severity of pneumococcal pneumonia in part by augmenting neutrophil function. Specifically, we show that 1) galectin-3 directly acts as a neutrophil-activating agent and potentiates the effect of fMLP, 2) exogenous galectin-3 augments neutrophil phagocytosis of bacteria and delays neutrophil apoptosis, 3) phagocytosis of apoptotic neutrophils by galectin-3(-/-) macrophages is less efficient compared to wild type, and 4) galectin-3 demonstrates bacteriostatic properties against S. pneumoniae in vitro. Furthermore, ad-back of recombinant galectin-3 in vivo protects galectin-3-deficient mice from developing severe pneumonia. Together, these results demonstrate that galectin-3 is a key molecule in the host defense against pneumococcal infection. Therapeutic strategies designed to augment galectin-3 activity may both enhance inflammatory cell function (by directly affecting neutrophil responsiveness and prolonging neutrophil longevity) and have direct bacteriostatic activity, improving clinical outcomes after severe pneumococcal infection.     

Local treatment with BPPcysMPEG reduces allergic airway inflammation in sensitized mice

According to the hygiene hypothesis, triggering the immune system with microbial components during childhood balances the inherent Th2 bias. In contrast, specific immunotherapy involves exposure of the patient to the allergen in order to achieve desensitization to subsequent contact.In a human in vitro allergy model the potential of the TLR2/6 agonist BPPcysMPEG to modulate antigen presenting cells and allergen-specific immune responses was evaluated. Specific immunomodulation via co-administration of the allergen and BPPcysMPEG enhanced expression of co-stimulatory molecules on DC and increased secretion of the proinflammatory cytokine TNF-α. Acting as an adjuvant, BPPcysMPEG elevated allergen-specific immune responses in co-culture with autologous lymphocytes. Although administration of BPPcysMPEG alone enhanced expression of co-stimulatory molecules on DC, proliferation of autologous lymphocytes was not induced.Based on this finding, the potential of BPPcysMPEG to reduce allergic airway inflammation by preventive modulation of the innate immune system via TLR2/6 agonization was investigated in mice. Local administration of BPPcysMPEG altered cellular influx and cell composition in BAL fluid. Furthermore, the Th2-associated cytokines IL-4 and IL-5 were diminished. Allergen-specific restimulation of cells from mediastinal lymph nodes and splenocytes suggested an alteration of immune responses. The treatment with BPPcysMPEG induced a Th1-dominated cytokine milieu in mediastinal lymph nodes, while allergen-specific immune responses in splenocytes were diminished. The co-administration of allergen and BPPcysMPEG reduced cytokine secretion upon restimulation in mediastinal lymph nodes and splenocytes.From these data we conclude that BPPcysMPEG was able to influence the immune system with regard to subsequent allergen contact by TLR2/6 agonization.     

Rapid development of vein graft atheroma in ApoE-deficient mice

Several animal models manifesting lesions resembling neointimal hyperplasia of human vein grafts have been developed, but no spontaneous atheromatous lesions in their vein grafts have been observed. We developed and here characterize a new animal model of vein graft atheroma, a maturated atherosclerotic plaque, in apoE-deficient mice. The lesion displayed classical complex morphological features and heterogeneous cellular compositions and consisted of a fibrous cap, infiltrated mononuclear cells, foam cells, cholesterol crystal structure, necrotic core with calcification, and neovasculature. Cell component analysis revealed smooth muscle cells (SMCs) localized in the cap region, macrophages which made up a large portion of the lesions, and CD4+ T cells scattered under the cap. Importantly, apoptotic/necrotic cells determined by TUNEL assay in vein grafts into apoE-/- mice were significantly higher than wild-type mice, although a similar number of proliferating cell nuclear antigen-positive cells in both types of lesions was found. Interestingly, vascular SMCs cultivated from aortas of apoE-deficient mice showed a high rate of spontaneous apoptosis/necrosis and a higher rate of cell death stimulated by a nitric oxide donor, sodium nitroprusside, H(2)O(2), and oxidized low density lipoprotein (LDL), although no difference in proliferation of both SMCs incubated with platelet-derived growth factor, angiotensin II, LDL, and oxidized LDL was seen. Thus, the pathogenic mechanisms of vein graft atheroma involve increased intimal cell death initiated by biomechanical stress and amplified by hypercholesterolemia, which leads to continuous recruitment of blood mononuclear cells to constitute atheromatous lesions. This mouse model resembling human vein graft disease has many advantages over other animal models.     

C-反应蛋白与动脉粥样硬化炎症的关系

Inflammation plays a pivotal role in atherogenesis. In addition to being a potent predictive and prognostic marker for major cardiovascular events, recent evidence indicates that C-reactive protein (CRP) might directly promote atherogenesis by exerting direct effects on vascular cells. Thus, CRP will become important novel pharmaceutical targets for the treatment of atherosclerosis. This review presents an overview of the current knowledge about the pathological role of CRP in atherosclerosis initiation and progression.     

Galectin-3 deficiency enhances type 2 immune cell-mediated myocarditis in mice

Experimental autoimmune myocarditis (EAM) is a mouse model of immune-mediated myocarditis and cardiomyopathy. The role of Galectin-3 (Gal-3), a β-galactoside-binding lectin, in autoimmune myocarditis has not been studied. Therefore, the aim of this study was to delineate the role of Gal-3 in myosin peptide-induced autoimmune myocarditis in mice. EAM was induced in relatively resistant C57BL/6J mice (wild type, WT) and in mice with a targeted deletion of Gal-3 gene (Gal-3KO) by immunization with myosin peptide MyHCα_334–352. Gal-3KO mice developed more severe myocarditis and more pronounced heart hypertrophy than WT mice. Increased infiltration of CD45⁺ leucocytes, CD3⁺ T cells, F4/80⁺ macrophages, and eosinophils was observed in hearts of Gal-3KO mice compared to WT mice on day 21 after EAM induction. Moreover, hearts of Gal-3KO mice had more T helper type 2 (Th2) cells, alternatively activated M2 macrophages, higher amounts of IgG deposits, and higher serum levels of IL-4 and IL-33 than WT mice. Ablation of Gal-3 in Th1-dominant C57BL/6J mice that are relatively resistant to EAM resulted in more severe disease characterized by type 2 cardiac inflammation. The complex effects of Gal-3 on EAM progression might be important in the consideration of therapeutic options for the treatment of EAM.     

Aortic adventitial angiogenesis and lymphangiogenesis promote intimal inflammation and hyperplasia

IntroductionAdventitial inflammation is known to influence neointimal formation and vascular remodeling. The present study was aimed to clarify the relationship between neointima hyperplasia and adventitial angiogenesis and lymphangiogenesis after balloon-induced aortic endothelial injury.MethodsSeventy male Wistar rats were randomly divided into six interventional groups and one control group. The intimal area/medial area ratio (I/M ratio), the adventitial macrophage index, and the number of adventitial microvessels (Ad-MV) and lymphatic vessels (Ad-LV) in the aorta were measured, and the mRNA expressions of VEGF-A, VEGFR-1, VEGF-C, VEGFR-3, PDGF-B, and PDGFR-β in the aortic wall were quantified by real-time RT-PCR.ResultsCompared with the control group, the I/M ratio, macrophage index, Ad-MV, Ad-LV, and the mRNA expressions of VEGF-A, VEGFR-1, VEGF-C, VEGFR-3, PDGF-B, and PDGFR-β in interventional groups increased significantly after balloon-induced injury. I/M ratio showed significant correlations with Ad-MV and Ad-LV after balloon intervention. Multiple linear regression analysis indicated that Ad-MV and Ad-LV were independent factors of intimal hyperplasia.ConclusionAdventitial angiogenesis and lymphangiogenesis are induced by intimal inflammation after balloon injury, and these neogenetic vessels in turn promote intimal inflammation and hyperplasia probably via delivery and activation of inflammatory cells.     

Expression of pentraxin 3 (PTX3) in human atherosclerotic lesions

Pentraxin 3 (PTX3) and C-reactive protein (CRP) are members of the pentraxin superfamily. PTX3 expression is induced in response to inflammatory signals, and is produced at sites of inflammation by several types of cell, primarily monocytes/macrophages, dendritic cells (DCs), endothelial cells, smooth muscle cells (SMCs), and fibroblasts, but is not produced by hepatocytes, which are a major source of CRP. The aim of our study was to investigate the expression pattern of PTX3 in human atherosclerotic lesions using a novel monoclonal antibody against PTX3. We examined coronary arterial thrombi containing an atherosclerotic plaque component removed from patients with acute myocardial infarction and human aortic tissues with various degrees of atherosclerosis sampled from autopsy cases. Immunohistochemical study of paraffin and frozen sections indicated that macrophages, mainly foam cells, expressed PTX3 in advanced atherosclerotic lesions. Interestingly, we also clearly observed PTX3-positive neutrophils infiltrating into atherosclerotic plaques, suggesting that PTX3 derived from neutrophils as well as macrophages plays an important role in atherogenesis.