Genistein On Of Ldlr-/ - Mice Atherosclerosis Development And Urocortin Expression In Rats With Allergic Asthma, Lung Tissue, Occurs

PartⅠGenistein thwarts the development ofatherosclerosis in LDLR-knockout miceBACKGROUND:Artherosclerosis (AS) and its complication are one of the maincauses for pathopoiesis and death. AS whose features are inflammatoryreaction and proliferation of fibrocyte, is defined as an inflammatorydisease. NF-κB and VCAM-1, a cytokine-inducible member of theimmunoglobulin gene superfamily, are expressed in the atheroscleroticplaques more than in the normal arterial tissue. Genistein is a principalisoflavone found in soy phytoestrogen, and it has structural similaritywith 17-βestradiol. Some studies indicate that genistein can inhibit theatherogenesis via suppressing the LDL formation, vascular smoothmuscle cell proliferation, thrombosis, and so on. Whether NF-κB andVCAM-1 participate in the process of genistein inhibiting theatherogenesis deserves further studies.OBJECTIVES:To examine the effect of genistein on atherosclerosis inLDLR-knockout mice; to investigate the relationship between the expression of NF-κB & VCAM-1 in the aorta and the process ofgenistein's effect on the atherogenesis in LDLR-knockout mice.METHODS:Twelve male LDLR knockout mice were allocated to model groupand genistein group equally and six C57BL/6J background mice were setas normal control. All the mice were put on Western diet in order tofacilitate atherogenesis. Genistein group mice were injected withgenistein and the model group mice were injected with the genisteinvehicle by hypodermic injection. The treatment lasted 56 days. Totalcholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL) andhigh-density lipoprotein (HDL) in plasma were quantitated bycommercially available kits. The atherosclerotic lesions were analyzed bythe H&E staining. The expression of NF-κB and VCAM-1 in the aortawas detected by RT-PCR and Western blot, respectively.RESULTS:1. The H&E staining showed that the atherosclerotic lesion size in modelgroup mice was (6.65±1.51)×10~6μm~2 and the size was increasedsignificantly versus normal control (0.65±0.28)×10~6μm~2 (p＜0.01).Compared to model group, the atherosclerotic lesion size in genisteingroup mice (3.684±1.18)×10~6μm~2 was reduced significantly (p＜0.05). Meanwhile the number of infiltrative inflammatory cellswas reduced obviously.2. By immunohistochemistry analysis, it was found that both endothelialcells and smooth muscle cells were positively stained of NF-κB andVCAM-1 in the aorta of model group mice rather than those in thenormal control. Compared to model group, the expression of NF-κB(p＜0.05) and VCAM-1 (p＜0.05) in the aorta of genistein group micewas reduced significantly. The similar result for the alteration ofVCAM-1 mRNA expression was also verified by RT-PCR.3. The levels of TC, TG, LDL and HDL in model group mice plasmawere 664.7±42.1 mg/dl, 512.34±30.4 mg/dl, 189.14±17.1 mg/dl and62.4±13.3 mg/dl respectively, so the serum cholesterol and lipidprofiles were increased significantly versus normal control (p＜0.01).However, compared to model group, the levels of TC, TG, LDL andHDL in genistein group mice plasma were 639.6±30.1 mg/dl,506.84±46.2 mg/dl, 182.84±25.5 mg/dl and 68.2±7.5mg/dl. There wasno statistical difference between the two groups (p＞0.05).CONCLUSIONS:In conclusion, genistein can inhibit the atherogenesis via decreasingthe NF-κB protein, VCAM-1 protein and VCAM-1 mRNA expression inthe aorta in LDLR-/-mice. PartⅡEnhanced expression of urocortin in lung tissues ofrats with allergic asthmaBACKGROUND:Bronchial asthma is defined as a chronic airway inflammatorydisease. However the molecular pathogenesis of this disease is stillunclear. Many inflammatory cells including mast cells, eosinophilegranulocyte and T lymph cell participate in it. Urocortin (UCN), a newmember of the CRH family, is synthesized and secreted by bothinterbrain and periphery tissue. The UCN synthesized by interbrain hasimmunosuppressive action. However the UCN synthesized by peripherytissue has proinflammatory function. UCN is also synthesized andsecreted by human mast cells and activated mast cells release more UCNand many other proinflammatory factors. As human mast cells participatein the pathogenesis of the bronchial asthma, whether UCN participates inthis process is still unclear. OBJECTIVES:To examine the expression profile of UCN in rat lung with allergicasthma; to study the effect of glucocorticoid on the expression of UCN inrat lung with allergic asthma.METHODS:Twenty-four male Sprague-Dawley rats were allocated to normalcontrol, asthma model, and dexamethasone group equally. The rats inasthma model and dexamethasone group were actively sensitized bysubcutaneous injection of ovalbumin (OVA) and suscitated by an aerosolof 1% OVA 2 weeks after sensitization. The dexamethasone group ratswere injected the dexamethasone (2mg/kg) before the half hour ofsuscitation. The treatment lasted 1 week, and once a day.Bronchoalveolar lavage and wright staining were taken to analyze theproportion and quantity of all inflammatory cells before 24 hours of thelast OVA suscitation. Inflammatory reaction of bronchus and lung tissuein all experimental rats was analyzed by the H&E staining. Theexpression of UCN in the bronchus and lung tissue of all experimentalrats was detected by RT-PCR,Western blot and immunohistochemistry,respectively. RESULTS:1. The H&E staining showed that, compared with the normal control,lung tissue in asthma model group appeared bronchostenosis,epithelial tissue hyperblastosis, bronchi hydropsia, inflammatory cellinfiltration and many other severe inflammatory reactions. However,the inflammatory reactions in lung tissue of dexamethasone groupwere alleviated obviously.2. Bronchoalveolar lavage and wright staining analysis showed that thetotal number of the all inflammatory cells in asthma model group andthe normal control were (36.2±4.6)×10~6/ml and (9.5±1.6)×10~6/ml.There was significant difference between the two groups (p＜0.01).Meanwhile, the number of acidophilic cell, macrophage andmacrophage were also increased in asthma model group rather thanneutrophilic granulocyte. The total number of the all inflammatorycells in dexamethasone group was (5.1±0.9)×10~6/ml and reducedsignificantly versus the asthma model group (p＜0.01). The number ofacidophilic cell, macrophage and macrophage were also reducedrather than neutrophilic granulocyte.3. The expression of UCN in normal rat lungs was verified by RT-PCR,Western blot and immunohistochemistry, respectively. The expressionof both UCN mRNA level and peptide level in asthma model grouprat lungs were increased significantly (p＜0.01) versus the normal control. However, the expression of UCN in dexamethasone group ratlungs was reduced, compared to the asthma model group (p＜0.01).CONCLUSIONS:In the present study, we first demonstrated that UCN was locallyproduced in rat lungs tissue and expressed more pronouncedly ininflammatory airway of asthmatic rats. Glucocorticoid treatmentmarkedly reduced the production of UCN in asthmatic lung tissues.Peripherally produced UCN in lung may act as a possible local autocrineand paracrine immune-inflammatory mediator in inflammatory airway ofallergic asthma rats.