Macrophage MED1 deficiency promotes the development of atherosclerosis in female ApoE and LDLR knockout mice / 西安交通大学学报(医学版)

【Objective】 To study the effect of macrophage mediator 1 (MED1) deficiency on atherosclerosis in female mice. 【Methods】 ApoE knockout (ApoE-/-), LDLR knockout (LDLR-/-), MED1fl/fl, and macrophage MED1 knockout (MED1△Mac) mice were recruited in the study. Two types of mouse model were constructed:ApoE and macrophage MED1 double knockout (MED1△Mac/ApoE-/-) mice and their littermate controls (MED1fl/fl/ApoE-/-). ② LDLR knockout (LDLR-/-) mice receiving bone marrow from MED1△Mac (MED1△Mac→LDLR-/-) or MED1fl/fl (MED1fl/fl→LDLR-/-) mice. Female mice from these two models were fed a Western diet (21% fat and 0.15% cholesterol) for 12 weeks to promote the development of atherosclerosis. Body weight, total cholesterol (TC), and total triglyceride (TG) content in plasma were measured dynamically. After Western diet feeding for 12 weeks, aortic tree and aortic root were collected and hematoxylin-eosin (H&E) and oil red O staining were performed. 【Results】 Plasma TC and TG did not significantly differ between MED1fl/fl/ApoE-/- control group and MED1△Mac/ApoE-/-experimental group. However, the plaque area in aortic tree and aortic root was significantly increased in MED1△Mac/ApoE-/-mice. Moreover, compared with that in MED1fl/fl→LDLR-/- control group, the plaque area of aortic tree and aortic root had an increasing trend in MED1△Mac→LDLR-/- mice group. 【Conclusion】 MED1 deficiency in macrophages promotes the development of atherosclerosis in female ApoE or LDLR knockout mice.

Comparison of histological characteristics of two experimental mouse abdominal aortic aneurysm models / 西安交通大学学报(医学版)

【Objective】 To compare the histological characteristics of porcine pancreatic elastase （PPE） induced abdominal aortic aneurysms （AAA） and angiotensin Ⅱ （AngⅡ） induced AAA in mice. 【Methods】 In the PPE group， the mouse abdominal aorta segment from the infrarenal abdominal aorta to the iliac artery was isolated and its branch arteries were ligated to avoid leakage during PPE perfusion. We perfused the isolated aorta segment with a PPE solution at a concentration of 1.5 U/mL for 5 min and then closed the abdominal cavity. The diameter of the abdominal aorta was measured before and 14 days after the surgery， and the perfusion segment of the arteries was collected at day 14 after the surgery. The histological characteristics of the aneurysm were analyzed and graded by histological and immunohistochemical methods. In the AngⅡ group， ten apolipoprotein E knockout mice were prepared， and AngⅡ [1 000 ng/(kg·min)] was infused with osmotic pumps for 28 days. The aorta was separated and the aneurysm aorta segment was analyzed. The wild type mice were used as normal health controls. 【Results】 In the PPE group， the diameter of the PPE perfused aorta segments increased and was significantly larger than the basal diameter ［（0.52±0.02） mm vs. （1.23±0.11） mm］ at day 14 after surgery. All the ten mice developed AAA after PPE application. The histological results showed typical pathological features of AAA in PPE perfused mice， such as elastic fiber breakage， smooth muscle exhaustion， and increased inflammation. Six of the ten mice developed aneurysms after AngⅡ infusion （6/10）. The aneurysms/dilatations were mostly in the suprarenal abdominal aorta， but also in the thoracic aorta and aortic arch. The histology analysis showed that the formation of arterial dissection was common after AngⅡ infusion， and the typical vascular “false lumen” was found. The breakage of elastic fibers， the exhaustion of smooth muscle damage， and the inflammatory response were not as typical as the PPE model in AngⅡ perfused animals. 【Conclusion】 The histological characteristics of PPE induced AAA are very typical and well present the inflammatory process in the development of aneurysm. The AngⅡ model is suitable for the study of aneurysms combined with aortic dissection. Both models have their own advantages and can complement each other.

Establishment and identification of secreted frizzled-related protein 4 transgenic mice and analysis of their biological properties / 西安交通大学学报(医学版)

【Objective】 To generate secreted frizzled-related protein 4 (SFRP4) transgenic mice and analyze their biological properties. 【Methods】 We generated SFRP4 transgenic mice by DNA microinjection and detected the expression of SFRP4 by qRT-PCR and Western blotting. 【Results】 SFRP4 transgenic mice were successfully generated by DNA microinjection. The expression of SFRP4 was dramatically increased in transgenic mice liver compared with that of wide type. 【Conclusion】 The transgenic mice model of SFRP4 was successfully established by DNA microinjection. It provides a good model for studying the function of SFRP4 and the mechanism of participating in metabolic diseases.

Overexpression of PPARγ induces adipogenic steatosis in mouse primary hepatocytes / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the effects of PPARγ overexpression on steatosis in mouse primary hepatocytes.</p><p><b>METHODS</b>Primary hepatocytes isolated from C57BL/6J mice were infected with either Ad/LacZ or Ad/PPARγ for 48 h. Steatosis of the primary hepatocytes was checked by Oil Red O staining. The mRNA and protein expression of adipocyte-specific genes PPARγ, aP2 and CideA were analyzed by using RT Real-time PCR and Western Blot.</p><p><b>RESULTS</b>Primary hepatocytes were small and even. Hepatocyte nuclei were round with dispersed chromatin and prominent nucleoli. Accumulated lipid droplets were observed in Ad/PPARγ-infected hepatocytes, but in Ad/LacZ-infected hepatocytes. Moreover, compared with Ad/LacZ-infected hepatocytes, the mRNA expression of PPARγ, aP2, FGF21 and CideA in Ad/PPARγ-infected hepatocytes were significantly induced, the protein expression of PPARγ and its target aP2 strongly increased.</p><p><b>CONCLUSION</b>over expression of PPARγ induces adipogenic steatosis in mouse primary hepatocytes.</p>

Study of α1 adrenoceptor-mediated vasoconstriction and protein expressions induced by mmLDL in mouse mesenteric artery / 中国药理学通报

Aim To investigate the effects of mmLDL on the up-regulation ofα1 receptors in moues mesenter- ic arteries. Methods Mice tail intravenous injection of mmLDL was used . Vitro sensitive myograph was empl- oyed to examine Noradrenaline ( NA) induced vascular contraction on mice mesenteric artery, and the mRNA and protein expressions ofα1 andα2 receptors were an-alyzed by real-time PCR and Western blot, respective-ly. Results mmLDL significantly increased NA in-duced concentration-contractile curve, and the data of Emax and pEC50 were from ( 122. 61 ± 9. 40 )% and (5. 65 ± 0. 05 ) in normal saline ( NS ) group to (161. 01 ± 6. 90 )% and ( 6. 20 ± 0. 08 ) in mmLDL group (P tion-contractile curve induced by NA towards right. Af-ter using mmLDL, the mRNA and protein levels of α1 adrenoceptor were significantly increased, but the mR-NA and protein levels of α2 adrenoceptor were not changed. Conclusion Tail intravenous injection of mmLDL enhances the vascular expressions of α1 adre-noceptors and the contractile effects mediated byα1 ad-renoceptors.

Activation of PPARαimproves PPARγ-induced fatty liver in the mouse / 中国实验动物学报

Object To investigate the effect of PPARαactivation on PPARγ-induced fatty liver in the mouse. Methods Wild type mice ( C57BL/6) aged 4 to 5 weeks were used as animal models.All mice were divided into four groups.The mice in the first group were fed with chow diet.The mice in the second group were fed with a diet containing 0.125%Wy-14,643, an agonist of PPARa, for 8 days.The mice in the third group were injected with Ad/PPARγvia tail vein for 5 day.The mice in the fourth group were firstly fed with Wy-14,643 diet for 3 days and then injected with Ad/PPARγvia tail vein for another 5 day.Mouse livers were collected and photographed.The effect of PPARαactivation on PPARγ-induced fatty liver was observed by H&E and Oil red O staining.Results Compared with the controls, wild-type mice treated with Wy-14,643 for 8 days exhibited marked hypertrophy of hepatocytes with increased cytoplasmic eosinophil-ia and proliferation of peroxisomes.The liver size was significantly increased in the wild-type mice treated with Ad/PPARγfor 5 days, and over-expression of PPARγstrongly induced hepatic steatosis.Importantly, the wild-type mice pretreated with Wy-14,643 for 3 days and then given Ad/PPARγinjection exhibited dramatically the increase of liver size, which might be due to the dual function of PPARa and PPARγ.Compared with the Ad/PPARγgroup, the Wy-14,643 pretreat-ment group showed a reduced hepatic steatosis.Conclusions Activation of PPARαby Wy-14,643 effectively improves PPARγ-stimulated hepatic steatosis, which provides a novel target for prevention and therapy of fatty liver.

Establishment of cholesteryl ester transfer protein transgenic rabbits by DNA microinjection and analysis of their biological properties / 中国实验动物学报

Objective The aim of this study was to generate human cholesteryl ester transfer protein ( CETP) transgenic rabbits and analyze their biological properties.Methods We generated human CETP transgenic rabbits by DNA microinjection, and detected the expression of human CETP by real-time PCR and Western blot assay.The activity of CETP was measured using an activity assay kit.Results Human CETP transgenic rabbits were successfully generated by DNA microinjection.Compared with wide type rabbits, the expression of human CETP was dramatically increased in the liver of the human CETP transgenic rabbits.The plasma CETP activity was also much higher in the liver of human CETP transgenic rabbits than that of control rabbits.Conclusions The model of human CETP transgenic rabbits is successfully established by DNA microinjection.It will provide a useful tool for the studies of CETP biological function and its involvement in the mechanisms of cardiovascular diseases.

Allicin suppresses atherosclerosis by up-regulating protein S-nitrosylation / 西安交通大学学报(医学版)

Objective To investigate the effect of allicin on the development of atherosclerosis in apoE-/-mice and explore its underlying mechanism from the perspective of protein S-nitrosylation.Methods Thirty male apoE-/- mice were randomly divided into 3 groups:control group (saline,ig),low-dose group (allicin,9 mg/kg·d, ig)and high-dose group (allicin,18 mg/kg·d,ig).They were fed with high cholesterol diet for 12 weeks.The levels of plasma lipids,oxidized-LDL (ox-LDL),malondialdehyde,tumor necrosis factor-alpha and nitric oxide (NO)were measured.The atherosclerotic lesions in aortic root were evaluated after hematoxylin and eosin staining and elastica van Gieson and immunohistochemical staining,respectively.Furthermore,in vitro experiments were performed using human umbilical vein endothelial cells (HUVECs).The HUVECs were treated with allicin (10μmol/L or 20 μmol/L)for 24 hours in the presence of ox-LDL (50 μg/mL).The level of NO in supernatant was measured by a nitrate/nitrite assay. The protein S-nitrosylation of the HUVECs was detected through immunofluorescence.Results The histological analysis revealed that allicin treatment not only significantly decreased the areas of the atherosclerotic lesion (all P <0.05)but also suppressed the macrophage accumulation and smooth muscle cell proliferation in the lesion.There was no significant difference in the levels of plasma lipids between control and treated groups.However,allicin exerted obvious anti-oxidative and anti-inflammatory effects. Interestingly,the allicin treatment led to marked increase of the plasma NO level (P <0.05)and aortic protein S-nitrosylation.The experiments in vitro further proved that the allicin up-regulated the levels of NO and protein S-nitrosylation in HUVECs treated with ox-LDL (P < 0.01 ).Conclusion Allicin can inhibit the development of atherosclerosis.The mechanism is associated with the up-regulation of protein S-nitrosylation in endothelial cells, which plays an important role in anti-oxidization and anti-inflammation.

Correlation between plasma nitric oxide and atherosclerotic lesion in rabbits / 西安交通大学学报(医学版)

ABSTRACT:Objective To analyze the correlation between plasma nitric oxide (NO)level and atherosclerotic lesion in high cholesterol-fed (HCD ) rabbits.Methods Twenty male Japanese white rabbits were divided randomly into two groups,which were fed with normal diet (control group,n =10)or HCD (experimental group, n =10 )for 1 6 weeks.At the end of the experiment,plasma lipid and NO levels were measured.The gross atherosclerotic lesions in each group were detected by Sudan IV staining while intimal lesion area was measured by hematoxylin/eosin (HE)and elastica van gieson (EVG).Moreover,the macrophages (MΦ)and smooth muscle cells (SMC)were detected by immunohistochemical staining.The correlation analysis was made to reveal the relationship between atherosclerotic lesions and plasma NO level.Results Compared with those in control group, the total cholesterol (TC),triglyceride (TG),low-density lipoprotein cholesterol (LDL-C)and NO levels all increased significantly in experimental group.Atherosclerotic lesions appeared on the vascular wall in the latter group.The area of atherosclerotic lesions and MΦ in the plaque had a positive association with plasma NO level. Conclusion There is a relationship between plasma NO level and the size of HCD-induced atherosclerotic lesions in rabbits.Meanwhile,the MΦ positive area in the atherosclerotic plaque is also associated with plasma NO level in cholesterol-fed rabbits,suggesting that plasma NO level may be associated with the occurrence and progress of early atherosclerosis.

DETECTING LOW DENSITY LIPOPROTEIN RECEPTOR MUTANT GENE OF RABBIT BY PCR / 药物分析学报

Objective Watanabe Heritable Hyperlipidaemic (WHHL) rabbits with low density lipoprotein receptor (LDLr) gene mutation have provided unprecedented opportunities for the study of human atherosclerosis, in order to confirm LDL receptor gene status in rabbits, we developed a simple PCR technique to detect LDL mutations in rabbits. Methods Rabbits genomic DNA were extracted from ear biopsy, and amplified by PCR to detect 12 bp deletion mutation in WHHL rabbits. PCR products were directly digested with BglⅠ, and then applied to polyacrylamide gel electrophoresis. Results PCR products from homozygous LDLr +/+ rabbits generated 2 bands of 212 and 94 bp after BglⅠ digestion, LDLr +/- rabbits generated 3 bands (294, 212, and 94 bp), LDLr -/- animals, however, generated only 1 product (294 bp). Conclusion This modified PCR method is simple and reliable.

Detecting low density lipoprotein receptor mutant gene of rabbit by PCR / 西安交通大学学报·英文版

Objective: Watanabe Heritable Hyperlipidaemic (WHHL) rabbits with low density lipoprotein receptor (LDLr) gene mutation have provided unprecedented opportunities for the study of human atherosclerosis, in order to confirm LDL receptor gene status in rabbits, we developed a simple PCR technique to detect LDL mutations in rabbits. Methods: Rabbits genomic DNA were extracted from ear biopsy, and amplified by PCR to detect 12 bp deletion mutation in WHHL rabbits. PCR products were directly digested with Bgl I, and then applied to polyacrylamide gel electrophoresis. Results: PCR products from homozygous LDLr +/+ rabbits generated 2 bands of 212 and 94 bp after Bgl I digestion, LDLr +/- rabbits generated 3 bands (294, 212, and 94 bp), LDLr -/-animals, however, generated only 1 product (294 bp). Conclusion: This modified PCR method is simple and reliable.