Oligomeric amyloid-ß targeted contrast agent for MRI evaluation of Alzheimer's disease mouse models.

Background: Oligomeric amyloid beta (oAß) is a toxic factor that acts in the early stage of Alzheimer's disease (AD) and may initiate the pathologic cascade. Therefore, detecting oAß has a crucial role in the early diagnosis, monitoring, and treatment of AD. Purpose: The purpose of this study was to evaluate MRI signal changes in different mouse models and the time-dependent signal changes using our novel gadolinium (Gd)-dodecane tetraacetic acid (DOTA)- ob5 aptamer contrast agent. Methods: We developed an MRI contrast agent by conjugating Gd-DOTA-DNA aptamer called ob5 to evaluate its ability to detect oAß deposits in the brain using MRI. A total of 10 control mice, 9 3xTg AD mice, and 11 APP/PS/Tau AD mice were included in this study, with the age of each model being 16 or 36 weeks. A T1-weighted image was acquired at the time points before (0 min) and after injection of the contrast agent at 5, 10, 15, 20, and 25 min. The analyses were performed to compare MRI signal differences among the three groups and the time-dependent signal differences in different mouse models. Results: Both 3xTg AD and APP/PS/Tau AD mouse models had higher signal enhancement than control mice at all scan-time points after injection of our contrast media, especially in bilateral hippocampal areas. In particular, all Tg AD mouse models aged 16 weeks showed a higher contrast enhancement than those aged 36 weeks. For 3xTg AD and APP/PS/Tau AD groups, the signal enhancement was significantly different among the five time points (0 min, 5 min, 10 min, 15 min, 20 min, and 25 min) in multiple ROI areas, typically in the bilateral hippocampus, left thalamus, and left amygdala. Conclusion: The findings of this study suggest that the expression of the contrast agent in different AD models demonstrates its translational flexibility across different species. The signal enhancement peaked around 15-20 min after injection of the contrast agent. Therefore, our novel contrast agent targeting oAß has the potential ability to diagnose early AD and monitor the progression of AD.

Integrating systematic biological and proteomics strategies to explore the pharmacological mechanism of danshen yin modified on atherosclerosis.

This research utilized the systematic biological and proteomics strategies to explore the regulatory mechanism of Danshen Yin Modified (DSYM) on atherosclerosis (AS) biological network. The traditional Chinese medicine database and HPLC was used to find the active compounds of DSYM, Pharmmapper database was used to predict potential targets, and OMIM database and GeneCards database were used to collect AS targets. String database was utilized to obtain the other protein of proteomics proteins and the protein-protein interaction (PPI) data of DSYM targets, AS genes, proteomics proteins and other proteins. The Cytoscape 3.7.1 software was utilized to construct and analyse the network. The DAVID database is used to discover the biological processes and signalling pathways that these proteins aggregate. Finally, animal experiments and proteomics analysis were used to further verify the prediction results. The results showed that 140 active compounds, 405 DSYM targets and 590 AS genes were obtained, and 51 differentially expressed proteins were identified in the DSYM-treated ApoE-/- mouse AS model. A total of 4 major networks and a number of their derivative networks were constructed and analysed. The prediction results showed that DSYM can regulate AS-related biological processes and signalling pathways. Animal experiments have also shown that DSYM has a therapeutic effect on ApoE-/-mouse AS model (P < .05). Therefore, this study proposed a new method based on systems biology, proteomics, and experimental pharmacology, and analysed the pharmacological mechanism of DSYM. DSYM may achieve therapeutic effects by regulating AS-related signalling pathways and biological processes found in this research.

E-vapor aerosols do not compromise bone integrity relative to cigarette smoke after 6-month inhalation in an ApoE-/- mouse model.

Cigarette smoke (CS) exposure is one of the leading risk factors for human health. Nicotine-containing inhalable products, such as e-cigarettes, can effectively support tobacco harm reduction approaches. However, there are limited comparative data on the effects of the aerosols generated from electronic vapor products (e-vapor) and CS on bone. Here, we report the effects of e-vapor aerosols and CS on bone morphology, structure, and strength in a 6-month inhalation study. Eight-week-old ApoE-/- mice were exposed to aerosols from three different e-vapor formulations-CARRIER (propylene glycol and vegetable glycerol), BASE (CARRIER and nicotine), TEST (BASE and flavor)-to CS from 3R4F reference cigarettes at matched nicotine concentrations (35 µg/L) or to fresh air (Sham) (N = 10 per group). Tibiae were analyzed for bone morphology by µCT imaging, biomechanics by three-point bending, and by histological analysis. CS inhalation caused a significant decrease in cortical and total bone volume fraction and bone density relative to e-vapor aerosols. Additionally, CS exposure caused a decrease in ultimate load and stiffness. In contrast, bone structural and biomechanical parameters were not significantly affected by e-vapor aerosol or Sham exposure. At the dissection time point, there was no significant difference in body weight or tibia bone weight or length among the groups. Histological findings revealed microcracks in cortical bone areas among all exposed groups compared to Sham control. In conclusion, because of the bone-preserving effect of e-vapor aerosols relative to CS exposure, e-vapor products could potentially constitute less harmful alternatives to cigarettes in situations in which bone health is of importance.

Effect of aldehyde scavenger-salicylamine on atherosclerosis of uremic ApoE-/- mice / 西安交通大学学报(医学版)

Objective: To observe the effect of aldehyde scavenger, salicylamine (SAM), on atherosclerosis (AS) and its phenotype in uremic apolipoprotein E knockout (ApoE-/-) mice. Methods:Uremic ApoE-/- mice model was created by 5/6 nephrectomy; control ApoE-/- mice were sham-operated. Three subgroups of experimental mice were set up: uremia SAM intervention group, uremia group and control group, which were treated with SAM (1 g/L) or vehicle for 6 weeks, respectively. After the intervention was completed, we assessed the body weight, blood pressure, renal function, serum lipid profile, serum SAM concentration, extent and characteristic of aortic atherosclerotic lesion in each group of mice. Results: Compared with control group: aortic AS lesion area, necrotic area and macrophage content in AS lesion increased but collagen content in AS lesion decreased in uremia group. SAM treatment for 6 weeks lessened the atherosclerotic lesion area, necrotic area and macrophage content of plaques, and meanwhile increased collagen content of plaques in uremic mice, not accompanied by changes in body weight, blood pressure, serum lipid profile or renal function. SAM did not accumulate or induce toxic effect on uremic ApoE-/- mice. Conclusion: Aldehyde scavenger SAM ameliorates renal injury-induced acceleration of AS, alters atherosclerotic phenotype, and increases the stability of plaques. These benefits are independent of effects on blood pressure, lipid profile or renal function. SAM does not accumulate or induce toxic effect in uremic ApoE-/- mice.

Quantifying blood-brain-barrier leakage using a combination of evans blue and high molecular weight FITC-Dextran.

BACKGROUND: Evans blue (EB) is the most widely used tracer to assess BBB leakage. However, a well-established method to obtain visualized and quantitative results of EB extravasation is presently unavailable. NEW METHOD: We reported a novel method to quantify BBB leakage by combining EB and high molecular weight FITC-Dextran (2000 kDa). EB was used for a long circulation duration (60 min) to detect BBB leakage. FITC-Dextran was used for a short circulation duration (10 min) to outline vascular contours. Confocal microscope imaging was used to obtain visualized images of BBB leakage. The result of dividing integrated optical density of EB by vascular areas outlined by FITC-Dextran was treated as the quantification of BBB leakage. RESULTS: This method proved workable in quantifying BBB leakage of specific regions in lipopolysaccharide-induced BBB disruption mice and apoE-/- mice. Sections processed with this method enabled further immunofluorescence staining. Through combining the results of EB extravasation and immunofluorescence staining, the colocalization of specific proteins and BBB disruption was achieved. COMPARISON WITH EXISTING METHODS: Colorimetric and spectrophotometric methods provide us with quantitative results of EB extravasation but fail to locate the specific regions. Fluorescence microscopy imaging can locate specific regions of EB extravasation but a well-established quantitative method is presently unavailable. Our method combines advantages of above two classic methods, providing us with visualized and quantitative information of BBB leakage based on EB extravasation in specific cerebral regions. CONCLUSIONS: The proposed method proved powerful in quantifying BBB leakage of specific regions, which may benefit studies regarding BBB disruption.

Ticagrelor promotes atherosclerotic plaque stability in a mouse model of advanced atherosclerosis.

OBJECTIVE: There is increasing evidence supporting the role of platelets in atherosclerotic vascular disease. The G-protein-coupled receptor P2Y12 is a central mediator of platelet activation and aggregation but has also been linked to platelet-independent vascular disease. Ticagrelor is an oral P2Y12 antagonist that is used as a standard treatment in patients after acute myocardial infarction. However, the effects of ticagrelor on advanced atherosclerosis have not been investigated. MATERIALS AND METHODS: Twenty-week-old apolipoprotein-E-deficient mice received standard chow or standard chow supplemented with 0.15% ticagrelor (approximately 270 mg/kg/day) for 25 weeks. The lesion area was evaluated in the aortic sinus by Movat's pentachrome staining and lesion composition, thickness of the fibrous cap, and size of the necrotic core evaluated by morphometry. RAW 264.7 macrophages were serum starved and treated with ticagrelor in vitro for the detection and quantification of apoptosis. In addition, oxLDL uptake in RAW 264.7 macrophages was evaluated. RESULTS: A trend toward the reduction of total lesion size was detected. However, data did not reach the levels of significance (control, n=11, 565,881 µm(2) [interquartile range {IQR} 454,778-603,925 µm(2)] versus ticagrelor, n=13, 462,595 µm(2) [IQR 379,740-546,037 µm(2)]; P=0.1). A significant reduction in the relative area of the necrotic core (control, n=11, 0.46 [IQR 0.4-0.51] versus ticagrelor, n=13, 0.34 [IQR 0.31-0.39]; P=0.008), and a significant increase in fibrous caps thickness (control, n=11, 3.7 µm [IQR 3.4-4.2 µm] versus ticagrelor, n=13, 4.7 [IQR 4.3-5.5 µm], P=0.04) were seen in ticagrelor-treated mice. In vitro studies demonstrated a reduction in apoptotic RAW 264.7 macrophages (control 0.07±0.03 versus ticagrelor 0.03±0.03; P=0.0002) when incubated with ticagrelor. Uptake of oxLDL in RAW 264.7 was significantly reduced when treated with ticagrelor (control 9.2 [IQR 5.3-12.9] versus ticagrelor 6.4 [IQR 2.5-9.5], P=0.02). CONCLUSION: The present study demonstrates for the first time a plaque-stabilizing effect of ticagrelor in a model of advanced vascular disease, potentially induced by a reduction of oxLDL uptake or an inhibition of apoptosis as seen in vitro.

Metabolism of benzo(a)pyrene by aortic subcellular fractions in the setting of abdominal aortic aneurysms.

As exposure to polycyclic aromatic hydrocarbons (PAHs; a family of environmental toxicants) have been implicated in cardiovascular diseases, the ability of the aortic tissue to process these toxicants is important from the standpoint of abdominal aortic aneurysms and atherosclerosis. Benzo(a)pyrene (B(a)P), a representative PAH compound is released into the environment from automobile exhausts, industrial emissions, and considerable intake of B(a)P is also expected in people who are smokers and barbecued red meat eaters. Therefore, knowledge of B(a)P metabolism in the cardiovascular system will be of importance in the management of vascular disorders. Toward this end, subcellular fractions (nuclear, cytosolic, mitochondrial, and microsomal) were isolated from the aortic tissues of Apo E mice that received a 5 mg/kg/week of B(a)P for 42 days and 0.71 mg/kg/day for 60 days. The fractions were incubated with 1 and 3 µM B(a)P. Post incubation, samples were extracted with ethyl acetate and analyzed by reverse-phase HPLC. Microsomal B(a)P metabolism was greater than the rest of the fractions. The B(a)P metabolite levels generated by all the subcellular fractions showed a B(a)P exposure concentration-dependent increase for both the weekly and daily B(a)P treatment categories. The preponderance of B(a)P metabolites such as 7,8-dihydrodiol, 3,6-, and 6,12-dione metabolites are interesting due to their reported involvement in B(a)P-induced toxicity through oxidative stress.

Effects of Hedan tablet on cytokins and oxidative stress factors in APOE-/-mouse / 天津医药

Objective To observe the effects of Hedan tablet on cytokines and oxidation factors in APOE-/-mouse, and to explore its effect on atherosclerosis and to explore its behind mechanism. Methods APOE-/-mice (n=50) were randomly divided into control group, model group, low dose Hedan tablet treatment group, high dose Hedan tablet treatment group and simvastatin treatment group. Mice in control group were given normal feed while mice in other groups were fed with high cho?lesterol diet. Hedan or Simvastatin was administrated intra-gastrically while normal saline was given to model group in the same route. After 12 weeks, mice were sacrificed to observe the mRNA level of tumor necrosis factor-α(TNF-αmRNA) in aorta by RT-PCR. Mean while, serum levels of interleukin-1 (IL-1), interleukin-10 (IL-10), malonaldehyde (MDA) and su?peroxide dismutase (SOD) were determined in different groups. Results Compared with control group, TNF-αmRNA tran?scription level as well as serum levels of IL-1 and MDA significantly increase while serum levels of IL-10 and SOD de?creased remarkably in model group, (P<0.01). Compared with model group, mRNA levels of TNF-αas well as serum levels of IL-1 and MDA were significantly decreased while serum levels of IL-10, SOD were greatly increased in low dose and high dose Hedan tablet treatment groups as well as in simvastatin treatment group (P<0.01). Conclusion Hedan tablet inhibit the formation of atherosclerosis through its anti-oxidation role and anti-inflammation role.

Genistein alleviates the development of nonalcoholic steatohepatitis in ApoE(-/-) mice fed a high-fat diet.

SCOPE: Genistein (GEN) is a compound that has been shown to alleviate hepatic steatosis. Here, we investigated its protective effects against non-alcoholic steatohepatitis (NASH) development in apolipoprotein E-deficient (ApoE(-/-) ) mice fed a high-fat diet (HFD). METHODS AND RESULTS: Wild-type and ApoE(-/-) mice were fed an HFD with or without GEN (0.5 g/kg diet) for 24 weeks. Body weights were reduced and fecal cholesterol excretion was increased by GEN. GEN supplementation lowered serum and hepatic cholesterol and lipid peroxidation levels, and hepatic heme oxygenase 1 protein levels in ApoE(-/-) mice. Hepatic expressions of scavenger receptors involved in oxidized LDL uptake, CD36 and scavenger receptor A, were downregulated by GEN. GEN reduced serum alanine aminotransferase and monocyte chemoattractant protein 1 levels, and hepatic nuclear factor-κB-mediated inflammatory gene expressions in ApoE(-/-) mice. These levels were higher in ApoE(-/-) mice fed an HFD than their corresponding wild-type mice. GEN also alleviated hepatic steatosis by reducing mRNA levels of monoacylglycerol O-acyltransferase 1, a target gene of peroxisome proliferator-activated receptor γ. CONCLUSION: GEN alleviated NASH as well as hypercholesterolemia and obesity in ApoE(-/-) mice fed an HFD. Restoration of altered cholesterol metabolism and oxidative stress may be involved in the protective effect of GEN against NASH development.

Effects of tonifying spleen and promoting blood circulation on the retina and Bruch membrane in apolipoprotein E-deficient mouse with dyslipidemia / 中华实验眼科杂志

Background Dyslipidemia is one of the major causes of age-related macular degeneration (AMD).At present,the study of the preventive and treating methods of A MD is still a hot spot.Objective The purpose of this study was to observe the effect of tonifying the spleen and promoting blood circulation on the retina and Bruch membrane in apolipoprotein E-deficient (ApoE-/-) mice with dyslipidemia.Methods Thirty-six ApoE-/-mice aged 2 months were randomly divided into the normal diet group,high fat diet group and medicine group.A diet with a higher content of fat was given for 5 consecutive months to the mice of the high fat diet group and medicine group,and in the last month,a concoction that tonifies the spleen and promotes blood circulation was gavagely administered in the medicine group,and an equivalent volumes of normal saline solution was administered in the same way in the normal diet group and high fat diet group.Total plasma cholesterol (TC),low density lipoprotein (LDL)and triglyceride (TG) were detected by (ELISA? Name of assay?) using the 7170 Hitachi automatic biochemical analyzer,and morphological changes of the retina and Bruch membrane were examined by light microscopy and transmission electron microscopy.The number of outer nuclear layer (ONL) cells,retinal pigment epithelial (RPE) cells and the thickness of the Bruch membrane were examined by semi-quantitative histopathology with the Mias 2000 Imaging Analyzer System.Results The concentrations of TC,LDL and TG were (6.47 ±0.49) mmol/L,(1.46 ±0.10)mmol/L and (0.62 ±0.21) mmol/L,respectively,in 7-month-old mice of the medicine group,showing a significant reduction in comparison with (10.53 ±0.30) mmol/L,(1.90±0.13) mmol/L,(1.15±0.29) mmol/L of the high fat diet group,and (9.63 ± 0.18) mmol/L,(1.12 ± 0.15) mmol/L,(0.88 ± 0.21) mmol/L in the normal diet group (P＜0.05-0.01).The disorder and atrophy of ONL and RPE cells,divergence of fiber of the Bruch membranes were found in both the high fat diet group and normal diet control group under the light microscope,and drusen formed in some of the mice in the high fat diet group.However,ONL and RPE were well organized in the medicine group.The cell numbers in the ONL and RPE layer in the 7-month-old mice were (23 124.00±755.18) and (10.75±0.59),respectively,in the medicine group,(19 107.00 ± 1436.82) and (8.55 ± 1.11),respectively,in the high fat diet group,(21 663.00± 1073.27) and (9.75 ±0.58),respectively,in the normal diet group,with significant differences among them (P＜0.05-0.001).Thickness of the Bruch membrane in the medicine group extensively reduced in high fat diet group and normal diet control group (P＜0.01).The ultrastructures of the RPE and Bruch membrane were much more improved in the mdedicine group.Conclusions Tonifying the spleen and promoting blood circulation can attenuate hyperlipemia in ApoE-/-mouse;furthermore,it lessens the pathological abnormalities in the ONL,RPE and Bruch membrane.

Establishment of a uremic apolipoprotein E knockout mouse model to explore the mechanism of uremic atherosclerosis / 西安交通大学学报·英文版

Objective: To establish a uremic apoE -/- mouse model to observe serum biochemical parameters and features of aortic root atherosclerosis (AS) in the model. Methods: A uremic model was induced surgically in apoE-/-mice, electrocautery of the right kidney at 8 weeks of age and nephrectomy (NX) of the left one 2 weeks later. Control mice were sham-operated. Two weeks after NX, renal functions were detected in the uremic and control mice to evaluate the efficiency of the model. After 10 weeks of NX, blood samples were taken to determine serum biochemical parameters, and aortic root was collected for frozen sections to investigate the lesion features of AS. Results: Two weeks after NX, renal functions declined significantly in the uremic mice compared with the control ones, and remained stable 8 weeks later either in males or in females. Ten weeks after NX, serum levels of TCH, TG and LDL-C were dramatically higher in the uremic mice than in the controls, whereas no differences in serum HDL-C or glucose concentration were found between the two groups. Aortic root plaque relative area increased significantly in the uremic mice compared with the controls either in males or in females; moreover, the lesion area was larger in female mice than in male ones. Conclusion: We established a uremic apoE-/- mouse model successfully, and this model is characterized by accelerated atherogenesis which is associated with an increase in serum lipid profile. This experimental model can be a useful tool to study the pathogenesis and therapeutic strategies of uremic AS.

Establishment of a uremic apolipoprotein E knockout mouse model to explore the mechanism of uremic atherosclerosis / 药物分析学报

Objective To establish a uremic apoE-/- mouse model to observe serum biochemical parameters and features of aortic root atherosclerosis (AS) in the model. Methods A uremic model was induced surgically in apoE-/- mice: electrocautery of the right kidney at 8 weeks of age and nephrectomy (NX) of the left one 2 weeks later. Control mice were sham-operated. Two weeks after NX, renal functions were detected in the uremic and control mice to evaluate the efficiency of the model. After 10 weeks of NX, blood samples were taken to determine serum biochemical parameters, and aortic root was collected for frozen sections to investigate the lesion features of AS. Results Two weeks after NX, renal functions declined significantly in the uremic mice compared with the control ones, and remained stable 8 weeks later either in males or in females. Ten weeks after NX, serum levels of TCH, TG and LDL-C were dramatically higher in the uremic mice than in the controls, whereas no differences in serum HDL-C or glucose concentration were found between the two groups. Aortic root plaque relative area increased significantly in the uremic mice compared with the controls either in males or in females; more-over, the lesion area was larger in female mice than in male ones. Conclusion We established a uremic apoE-/- mouse model successfully, and this model is characterized by accelerated atherogenesis which is associated with an increase in serum lipid profile. This experimental model can be a useful tool to study the pathogenesis and therapeutic strategies of uremic AS.