Virtual Screening Of New Cholesterol Lowering Drugs Targeting DHCR24 And The Preliminary Study Of Its Efficacy

High cholesterol levels in the human body can cause many diseases,especially cardiovascular diseases.Cholesterol is mainly produced by endogenous synthesis,accounting for 80% of the total content.The last step of the endogenous synthesis of cholesterol is the reduction of desmosterol to cholesterol,catalyzed by enzyme DHCR24(3 β-hydroxysterol-24-reductase).The mutation of DHCR24 gene(one-point mutant E191 K,N294T,K306 N,Y471S and double mutant N294T/K306N)may result in the decrease of enzyme activity and the decrease of cholesterol content.In the present study,we carried out virtual screening to develop a new type of cholesterol-lowering drugs targeting DHCR24.The positive rate of virtual screening is higher than that of traditional screening.The existing database of small molecule drugs were used for screening so that the process of drug-like screening for small molecule inhibitors can be omitted.First,we established,optimized and decided the structural model of DHCR24 protein by homology modeling and molecular dynamics.Molecular docking and virtual screening techniques were used to screen the DrugBank database.First 50 optimal best results(DHCR24-FAD-candidates complexes)were collected,which can be competitive inhibitors candidates of DHCR24.Then,we further performed the AutoDock 4 cluster analysis of these 50 results.Finally,we selected 4candidate drugs: OND1,OND2,OND3,OND4.HepG2 cell culture platform and high performance liquid chromatography(HPLC)was used to test the effect of 4 candidate components on inhibiting the activity of DHCR24 and decreasing the cholesterol content in cells.The results showed that the four groups of drugs and the positive control U18666A(known as DHCR24 non-competitive inhibitor)reduced the cholesterol content significantly in a given dose.Then,we studied again the cholesterol-lowering effect of four candidates by the method of fluorescence staining of cholesterol(filipin).The results confirmed that the cholesterol-lowering effects of the four components were very significant.Finally,we studied the mechanism of the inhibition of those candidates components on DHCR24 by the dynamic simulation analysis.In summary,we found four novel DHCR24 inhibitors candidates and the preliminary experiments had proved the effect of these inhibitors.The research laid a solid foundation for the development of new cholesterol lowering drugs targeting DHCR24.