Semi-quantitative Analysis Of MDR3 Gene MRNA Expression In The Liver Of Cholelithiasis Patient

PrefaceCholesterol cholelithiasis is an exceptionally common and economically significant digestive disease. Epidemiologic and family studies indicate that cholesterol gallstone formation is in part genetically determined. Cholesterol gallstone disease represents a failure of biliary cholesterol homeostasis in which the physicalchemical balance of cholesterol solubility in bile is disturbed. The primary pathophysiologic defect in both mice and humans is unphysiologic cholesterol supersatu-ration of gallbladder bile. Because phospholipids are a main carrier and solvent of cholesterol in hepatic bile, genetic variations in .biliary phospholipids metabolism might affect the risk of gallstone formation. MDR3 is the phosphatidylcholine translocator across the canaljcular membrane of the hepatocyte. The function of the MDR3 gene has been further elucidated through disruption of the marine homologue. In this study , we sought to better understand the relationship between the MDR3 gene and gallstone formation.Patients and MethodsTissue specimens. 14 liver tissue specimens were taken from patients with gallstone, which were the trial group. 5 liver tissue specimens were taken from patients without gallstone , one was patient with bladder cancer, one was liver caner, and the last was from corpse,which were the control group.RNA isolation and cDNA synthesis. Total RNA was isolated from the liver specimens using Trizol reagent by the modified method as described previously. First - strand cdna were synthesized from total RNA using Reverse Transcription System reagent.Reverse Transcription - Polymerase Chain Reaction. Polymerase chain reaction (PCR) conditions were firstly at 94℃ for 5 minutes , and at 94℃ for 30 second, at 60℃ for 40 second, at 12℃ for 1 minute for 35 cycles ,and last at 12℃ for 5 minutes. The PCR products were run on ethidium bromide - stained pam gels.ResultsThe MDR3 mRNA expression were markedly low in the liver specimens of patients with gallstone compared with the levels in specimens of control group ( p <0. 01) .DiscussionMDR3 belongs to a large supergene family of P - glycoproteins, found in both eukaryotes and mammals, originally named multidrug resistance (MDR) genes. Most of MDR3 were found in liver in the canalicular membranes of hepatocyte, which was the phosphatidylcho-choline translocator across the canalicular membrane of the hepatocyte. In this study, The MDR3 mRNA expression were markedly low in the liver specimens of patients with gallstone compared with the levels in specimens of control group, which indicate that the MDR3 may affect the gallstone formation. As MDR3 was the phosphatidylchocho-line translocator, if the MDR3 mRNA expression was decreased, the MDR3 pgp will be low . So the phosphatidylchocholine in the bile willdecrease. However, phospholipid is an important element in bile, which is a carrier and solvent of cholesterol in hepatic bile. So the cholesterol may be supresaturation. This would result in the the formation of gallstone. The result in this study corresponds with other study in abroad.Conclusion1, The MDR3 mRNA expression were decrease in the liver of patients with gallstone.2, The MDR3 may affect the gallstone formation.