Emodin Molecular Mechanisms Of Atherosclerosis In The Arteries Of The TLR4-mediated

BackgroundAtherosclerosis is the main pathology basis to coronary heart disease。 Inflammation played a critical role in the process of occurrence and development in atherosclerosis. And inflammation is also vulnerable plaques in atherosclerosis, which can cause acute coronary syndromes. There is a significantly increasing mRNA and protein expression of the inflammatory patches.The disordering balance between inflammatory and anti-inflammatory factor are the important molecular biology plaques rupture mechanism. TLR4plays a very important role of signal transduction in AS plaque formation and development process. We can gain some new ideas about AS treatment and prevention when we study deeply the TLR in AS, the effect of the development and related mechanism. Traditional Chinese medicine has much effect targets and many advantages in atherosclerosis. In recent years, some traditional Chinese medicine has been used to prevent atherosclerosis and related disease, and shows good effect. This experiment mainly discusses the role of TLR/MyD88/NF-κB signaling pathway in AS. The curative and the molecular mechanism of emodins has been studied in AS patches.ObjectiveAS models are established on the ApoE-/-mices. Through analyzing AS dynamicly and TLR signaling pathways comprehensively the role of TLR/MyD88/NF-κB signaling pathway in AS was discussed. The inhibition of emodin and its molecular mechanism of TLR4-mediated atherosclerotic inflammation were studied.Method60male apoE-/-mice were feed with common granule one week, and then were divided into model group (n=15) and emodin group (n=45) randomly. Then the mices fed with emodin were divided into high dose group (1200mg/kg d), mid-dose group (900mg/kg d.) and low dose group (600mg/kg d.) randomly,15in a group. The model mices were fed with high cholesterol feed (0.25%cholesterol+15%fat).The mices fed with emodin were fed with high cholesterol feed+emodin. All the mices were put to death12weeks later. Body weigh, Lipid measurement, pathologic staining, histopathological analysis, RT-RCR and Western blot were observed at the same time.Result1.Weight changeAt12week, body weight in all groups increased. The body weight of model group was highest and significantly higher than high dose emodin group (P<0.05).2. Lipid levelsEach group TC concentration was higher than normal. Three emodin treatment group were significantly lower level of TC (P<0.05～0.01), and high dose group of emodin significantly lower than low dose group (P<0.05). A significant dose dependent of the role of drugs was shown.The LDL-C concentrations in three emodin treatment group are greatly reduced, and the high dose group and the mid-dose group were significantly lower than the model group (P<0.05). Low doses group and the model group have no significant difference(P>0.05). And there is no significant difference in the three emodin treat groups (P>0.05).3. Serum inflammatory factorThe level of serum hsCRP were significantly reduced in three emodin treat groups (P<0.05～0.01), and which was below significantly in high dose group than the low dose and mid-dose group (P<0.01).Fib in three emodin treat groups were significantly lower than the model group (P<0.05～0.01), and high dose group is significantly lower than the low dose group (P<0.01)and mid-dose group(P<0.05).4. Pathologic stainingThere is been seen that AS range of lesions in aortic surface is reducing in emodin treat groups in general pathology. This reducing was consistent with the increase of emodin dose. 5. Immunohistochemical detectionImmunohistochemical staining showed that the TLR.4, TNF alpha, IL-6and MyD88local expression in model group and three emodin intervention group within the plaques. The amount expressions were significantly reduced in emodin intervention groups. With the increase of emodin dose, inflammatory factor expressed reduced significantly.The plaques by special dyeing and immunohistochemical detection show that the emodin intervention can significantly increase patchs collagen content (P<0.05-0.01) and reduce plaques lipid and macrophages content (P<0.05-0.01).6. RT-PCRThe mRNA level of the TNF-α, IL-6in emodin treat groups are significantly lower than the model group (P<0.05～0.01). The expression of high dose and mid-dose groups were lower than the low dose group (P<0.05).7. Western blotThe TLR4protein expression level were significantly reduced in high dose and mid-dose groups(P<0.05). The low dose group had the trend of decreasing but no statistically significant (P>0.05).TNF-a and IL-6of protein level were significantly reduced (P<0.05-0.01) in three emodin treat groups. The high dose group was lower than in low doses group(P<0.05), There was no significant difference between mid and low doses (P>0.05).Conclusion1. The signal way of TLR4/MyD88/NF-κB in the high fat feeding ApoE-/-mice is a close correlation with the AS patches occurrence and development;2. Emodin can block the molecules excessive activation in the signal pathway of TLR/MyD88/NF-κB which was the important mechanism of intervention the origin and development of AS.