Studies On The Role Of Liver Lipoprotein Lipase In Lipid Metabolism And Mechanism

LPL(lipoprotein lipase)is a classic enzyme which is the rate-limiting enzyme for the hydrolysis of the triglyceride (TG) core of circulating TG-rich lipoproteins, chylomicrons, and very low-density lipoproteins (vLDL).It plays very important role in regulating glucose and lipid metabolism and can express in various of tissues,including cardiac,skeletal muscle and kidney to exert tissue-specific functions.It has been proved that deficiency of LPL in those tissues will cause disfunctions in lipid or glucose storage or utilization. Liver is the key organ in lipid and glucose homestasis,however,the function of LPL in liver is not well-understood yet.we used Cre/LoxP system to generate a mouse model with the LPL gene selectively ablated within hepatocytes to investigate the biofunction of LPL in liver.Though the knock-out mice showed no change in glucose homeostasis,greatly increase in serum TG level in fasted and fed states were observed by us.Then we applied P407test and Postprandial TG test to check ability of lipid clearance and synthesis respectively,and in Postprandial TG test,we observed significant increase of serum TG level in liver-specific LPL KO mice compare with the wild type(WT) mice when it showed no difference in P407test.All these data indicate that LPL in liver may have a critical role in lipid metabolism.