Study Of The Effect Of Glycosaminoglycan From Scallop Skirt On Macrophage Lipoprotein Metabolism And Lipoprotein Receptor Expression

Objective To investigate the effect of scallop skirt of glycosaminoglycan(SS-GAG) on the lipoprotein oxidation and lipoprotein receptor expression in macrophage, and to discuss its mechanism of antiatherosclerosis .Methods 1.The mouse macrophage RAW264.7 were cultured in vitro ,and theapoptosis model of macrophage were established by incubation with Oxidized LDL. MTT chromatometry was used to study the effect of SS-GAG on macrophage Toxicity and proliferatory activity after oxidation injury.2. The cell model was established by culturing mouse macrophage RAW264.7 in vitro. A lot of biochemistry methods including xanthine oxidase method and TBARs were used to study the effect of SS-GAG on macrophage lipoprotein oxidation process by testing the oxidation production of lipoprotein (MDA and Conjugated Dienes) and activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-PX) and myeloperoxidase (MPO).3. The cell model was established by culturing mouse macrophage RAW264.7 in vitro. RT-PCR and immunohistochemistry method were used to detect the effect of SS-GAG on macrophage low density lipoprotein expression.4. The cell model was established by culturing mouse macrophage RAW264.7 in vitro. RT-PCR and immunohistochemistry method were used to test the effect of SS-GAG on expression of protein and gene transcription of macrophage high density lipoprotein (SR BI).5. The cell model was established by culturing mouse macrophage RAW264.7 in vitro. RT-PCR were used to detect the effect of SS-GAG on gene transcription on macrophage injured by OX-LDL.Recults 1. Compared with the normal group, the macrophage proliferatoryactivity ofSS-GAG group were no signifigence difference .This demonstrated that SS-GAGhad no toxicity on macrophage within the experiment concentration .2. After incubated with OX-LDL SO^g/ml for 24 h, proliferatory activity of of mouse macrophage were down regulated evidently. Compared with model group, proliferatory activity of macrophage was up regulated evidently. There was dose-effect relationship in this phenomenon. The SS-GAG 40Qag/ml group had the max effect. The effect of SS-GAG SOOjUg/ml group was less than 400/ig/ml group.3. After incubated with OX-LDL for 24 h, activity of MPO and production of MDA and Conjugated Dienes were increased, activity of GSH-PX was decreased. Compared with model group, SS-GAG up regulated activity of GSH-PX, down regulated activity of MPO, decreased Lipid peroxidation production. There was dose-effect relationship in this phenomenon.4. After incubated with OX-LDL 50/ig/ml for 24h, expression of protein and mRNA of LDL-R in mouse macrophage RAW264.7 were down regulated. Compared with model group, expression of protein and mRNA were up regulated in SS-GAG group. The 200//g/ml group had the max effect. There was dose-effect relationship in this phenomenon.5. After incubated with OX-LDL 5Q?g/ml for 24h, expression of protein and mRNA of SR BI in mouse macrophage RAW264.7 were down regulated. Compared with model group, expression of protein and mRNA in SS-GAG group were up regulated in different level. The effect of SS-GAG was more evident. There was dose-effect relationship in this phenomenon.6. Compared with normal group, mRNA expression of OX-LDL injured group were increased obviously. The expression of CD36 were down regulated in groups who were incubated with SS-GAG in advance. The effect of SS-GAG was more evident. There was dose-effect relationship in this phenomenon.Conclusion: SS-GAG can inhabit the apoptosis of macrophage which is introduced byOX-LDL. SS-GAG can impress the oxidation of LDL in macrophage by up regulating activity of MPO and down regulating activity of GSH-PX. SS-GAG can imply its antiatherosclerosis action by up regulating expression of LDL—R,SR-BI and down regulating expression of CD36.Postgraduate Wang Shao-Jun (Pharmacology)Directed by Prof. Liu Sai...