Effects Of Epigallocatechin-3-gallate On LPS-induced Glucose Transporter 1 And The Key Enzymes Of Glycolysis In Mouse Macrophages

Inflammation is a kind of immune system to neutralize the pathological state of normal physiological reaction.However,unbalanced or continuous inflammation will lead to further tissue damage,and also contact with the development of a variety of chronic disease.M1 macrophage is including in pro-inflammation,when macrophages differentiate to a proinflammatory phenotype M1,there are series of inflammatory reactions,such as the activation of NF-κB,the secretion of proinflammatory factor,the generation of ROS products and rearrangement of the cellular metabolism of glucose.The reprogramming of M1 make the main metabolism of cells to switch with TCA cycle to aerobic glycolysis.Epigallocatechin gallate(EGCG)is a major of polyphenols in green tea,also is the main active substances,have anti-inflammatory,antivirus,antitumor and antioxidant activity,also can inhibit oxidative damage in multiple organs,such as heart,kidney,lung and spleen.On the cell surface EGCG can combine with 67 LR to affect a variety of physiological functions,including cell signaling pathways and the secretion of proinflammatory factor,etc.Also some researches confirm that EGCG can inhibit the expression of GLUT1,the mainly glucose transporter on the surface of the cell membrane,thereby reducing cellular uptake of glucose.For detection the effect of EGCG on M1 macrophages glucose uptake and glycolysis,We use the model of inflammation is induced by LPS in mouse macrophage.Cells including RAW264.7 cell line and mouse bone marrow derived macrophages(BMDM)are used in experiments.This study selected the macrophages mainly glucose transporter GLUT1 and the key glycolytic enzymes hexokinase 2(HK2),u-6-phosphofructo-2-kinase(u-PFK2)and pyruvate kinase(Pkm).The cells are pretreated with EGCG(12.5 μM)for 2h and stimulated with LPS(100ng/ml)for24h.At same time,the control,EGCG pretreated and LPS treatment are implemented.We found that EGCG inhibited the expression of GLUT1,HK2,u-PFK2,Pkm sitimulated with LPS in RAW264.7 cell line and mouse bone marrow derived macrophages at mRNA level.EGCG also inhibit the uptake of glucose and theactivity of the key glycolytic enzyme HK2,u-PFK2 and Pkm of cells.This finding provides experimental basis for future study on the inhibition effects of EGCG on the metabolic reprogramming.