Mechanism Of Lovastatin Regulating Growth And Lipid Metabolism Of Hyphantria Cunea

Juvenile hormone(JH)and ecdysteroids(20E)are two important hormones in insect development that play crucial roles in regulating insect development,metamorphosis,and reproduction.The main target of statin drugs is 3-hydroxy-3-methylglutaryl-coenzyme A reductase(HMGR),which competitively inhibits the synthesis of cholesterol in mammals.In insects,HMGR is a key enzyme in the juvenile hormone synthesis pathway,responsible for catalyzing the biosynthesis of mevalonic acid(MVA).While statin drugs are widely used in clinical settings,their effects on insect growth and development are less studied,and the mechanisms of their regulatory actions are still unclear.In this paper,we focused on the worldwide quarantine pest,the gypsy moth(Lymantria dispar),as the test insect and systematically analyzed the effects and mechanisms of lovastatin on lipid metabolism and growth and development of gypsy moth larvae.Gypsy moth larvae were treated with lovastatin using a gastric toxic method,and various assays were performed including bioassays,measurements of juvenile hormone synthesis pathway,ecdysteroid synthesis pathway,expression levels of key genes involved in lipid metabolism,measurements of key enzyme activities,and Nile red staining.The following conclusions were drawn from the study:(1)Lovastatin exhibits significant insecticidal effects against gypsy moth larvae,which arise from the inhibition of larval feeding and weight gain,as well as the promotion of larval molting processes.(2)Lovastatin significantly inhibits fatty acid synthesis in gypsy moth larvae,acceleratesβ-oxidation of fatty acids,promotes fatty acid decomposition,and significantly reduces the content of triglycerides(TG)in gypsy moth larvae.It also decreases the size and abundance of lipid droplets in the fat body.(3)Following treatment with lovastatin,the expression levels of key genes involved in the juvenile hormone synthesis pathway,Hc JHAMT and Hc MVK,were significantly downregulated,while the expression levels of key genes involved in the ecdysteroid synthesis pathway,Hc CYP306 and Hc CYP314,were significantly upregulated in gypsy moth larvae.This indicates that lovastatin inhibits juvenile hormone synthesis and promotes ecdysteroid synthesis,thereby affecting larval molting in gypsy moth larvae.In conclusion,this study systematically analyzed the regulatory effects of lovastatin on the growth,development,and lipid metabolism of gypsy moth larvae.The research findings provide new insights into the mechanisms of HMGR inhibitors in regulating insect growth and development and lay the foundation for the potential application of HMGR inhibitors as environmentally friendly agents for pest control.