Role Of Protein-tyrosine Phosphatase SHP-2 In Early Atherosclerosis Formation In Apoe-knockout Mice

Objective:Atherosclerosis is a common disease with multiple path ogenic factors,complicated pathogenesis and great potential harmfulness.Src homology 2 domain-containing protein tyrosine phosphatase participa ted in the physiological processes of embryo development,cell metabolis m,proliferation and apoptosis.The molecular mechanism of AS is widel y studied.This research group aims to investigate the effects of Src Ho mology 2 Containing Protein Tyrosine Phosphatase on atherosclerosis by using specific inhibitor PHPS1 on the progression of AS in apo E^-/-mic e.Methods:1. vivo studies:28 apo E^-/-Mice were divided randomly into 2 groups:control group（Equivalent normal saline）and PHPS1（1.0mg/kg）treated group fed with high fat diet for 4 weeks,blood was taken from the eyeball to measure blood glucose and lipid levels.Descending aorta total oil red staining and Aortic root cross section hematoxylineosin staining were used to evaluated the changes of lesion al areas;immunohistochemical staining and Sirius scarlet were used to ev aluated cellular components;and moreover,q RT-PCR were used to asse ss the m RNA of CD36、scavenger receptor A、Toll-like receptors2、Toll-like receptors4;western blot methods were used to assess the phosphor ylation levels of ERK and PI3K/AKT signaling pathways.2.vitro studies:In the PHPS1 treatment group,0.25μL ox-LDL（final concentration of 50ng/ml）,1μL PHPS1（10μmol/L）and 1μL monodisperse fluorescent microspheres（final concentration of 0.5μl/ml）were added to each well.In the control group,0.25μL ox-LDL（final concentration of 50ng/ml）,1μL DMSO of normal saline and 1μL of monodisperse fluorescent micro globule（final concentration of 0.5μl/ml）were added to each well to int erfere with bone marrow-derived macrophage cells in mice for 16 hours.The green fluorescence deposition in BMDM was observed to evaluate t he phagocytosis of macrophages.Results:1. Comparison of blood glucose and lipid levels in serum of miceCompared with the control group,the blood glucose and lipid level s in PHPS1 treatment group were similar（P>0.05）,and the differences were not statistically significant.2. Staining results of tissue sections2.1 Comparison of oil red O staining results of descending aortaThe positive area（red）of oil red O in descending aorta of PHPS1treatment group was significantly increased compared with the control group（P<0.05）,and the difference was statistically significant.2.2 Comparison of the results of HE staining,Wolverine scarlet staining and immunohistochemical staining in apo E^-/-mouse aortic root para ffin sectionsCompared with the control group,the total area of HE stained plaq ues in PHPS1 treatment group（P<0.05）increased,and the difference was statistically significant.Mac-2 immunohistochemical staining showed an increase in macrophage positive area（P<0.05）,and the difference w as statistically significant.The positive area of SM-actin immunohistoche mical staining smooth muscle cells（P>0.05）was similar,but the differ ence was not statistically significant.The collagen-positive area（P>0.05）in the scarlatina staining plaque was similar,but the difference was not statistically significant.3. Influence of phagocytosis of BMDMsCompared with the control group,the green fluorescence intensity in BMDMs of PHPS1 treatment group was increased（P<0.01）,and the difference was statistically significant.4. Comparison of m RNA expression levels of scavenger receptor C D36,SR-A1,Toll-like family receptor TLR-2 and TLR-4Compared with the control group,CD36 and SR-A1 mrna expressio n levels of scavenger family receptors in PHPS1 treatment group were s ignificantly increased（P<0.05）,and the difference was statistically signi ficant.The m RNA expression levels of TLR-2 and TLR-4（P>0.05）wer e similar,and the difference was not statistically significant.5. Comparison of phosphorylation levels of ERK and PI3K-AKT pa thwaysCompared with the control group,the phosphorylation level of ERK（P<0.01）,PI3K-AKT（P<0.05）in PHPS1 treatment group was signi ficantly increased,and the difference was statistically significant.Conclusions:1.The tyrosine phosphatase SHP-2 inhibitor PHPS1 enhanced the p hosphorylation levels of proteins in ERK and PI3K-AKT signaling path ways,and promoted the overexpression of CD36 and SRA1 receptors o n the surface of macrophages.2.PHPS1 increases the phagocytosis ability of macrophages to ox-L DL,and finally promotes the formation of macrophage derived foam cel ls and speeds up the progression of AS.SHP-2 plays a negative role in the formation of macrophage derived foam cells and is a factor preven ting the formation of early AS,so it can be used AS a research targetf or AS prevention.