Regulation Of LncRNA Lockd In The Disorder Of Liver Lipid Metabolism Induced By Maternal Obesity

Background: Obesity during pregnancy is becoming an increasingly serious public health problem.Maternal obesity not only affects women health,but also has adverse effects on the short-term and long-term health in offspring.The risk of obese mother having premature birth,neonatal malformations,huge infants,fetal distress and perinatal deaths is significantly elevated.Maternal obesity is also an important risk factor for obesity and metabolic disorders in childhood and adulthood,but its pathogenesis is still controversial.The "Developmental origins of health and disease"(DOHaD)has received increasing attention in recent years.The latest view is that the metabolic pattern of an individual in adulthood may have been affected by the intrauterine nutritional environment during infancy or even in the fetal period.The overuterine environment of obese pregnant women can affect the development of important organs in the embryonic stage,thereby increasing the risk of various chronic diseases such as obesity,hyperlipidemia and diabetes in their offspring.Therefore,studying the effect of maternal obesity on lipid metabolism in offspring and revealing its molecular mechanism is important for early prevention and control of chronic diseases.Recent studies have found that long noncoding RNA(LncRNA)is involved in the development of chronic metabolic diseases.LncRNA is a type of single-stranded RNA molecule with a transcript length of more than 200 nt.It is considered to be a "junk gene" due to the lack of an open reading frame and the ability to encode any protein.However,recent studies have shown that LncRNA is involved in a variety of physiological and pathological processes.Among them,the association between LncRNA regulatory changes and progeny "metabolism recombination" caused by maternal obesity is unclear.Therefore,this study aimed to elucidate the role of potential lipid metabolism-associated LncRNA in progeny liver metabolism and to identify relevant signaling pathways.Methods: Female C57/BL6 mice were used to establish animal models.Obese dams were fed a high-fat diet for 10 weeks to induce maternal obesity(45% of energy was derived from fat)and control mice were fed standard chow(15% of energy was derived from fat).The dams and the healthy male mice were mated in 2:1 ratio,and all the dams gave birth freely.The offspring were weaned 3 weeks after birth and fed standard feed.dams and offspring weight were monitored weekly.Blood glucose and blood lipids were monitored at 3 and 8 weeks of age,respectively.As the offspring were breastfed for the first 3 weeks after birth,all nutrients in the offspring during the fetal period and 3 weeks within birth came from the mother.Therefore,to exclude other factors,a subset of offspring(CON,n=3;OB,n=3)were sacrificed at 3 weeks of age,and liver samples were used for RNA-sequencing analysis.The bioinformatics analysis of the sequencing data was carried out by R language and SPSS 22.0.The expression profile of LncRNA in the liver tissue of the offspring was analyzed,and the differential LncRNA was screened.The downstream target of LncRNA was predicted by an online site and the LncRNA-miRNA-mRNA network relationship was analyzed.The biological function and enrichment pathway analysis of downstream targets were performed using the Gene Ontology(GO)and KEGG(Kyoto Encyclopedia of Genes and Genomes)pathways.The expression of LncRNA and downstream targets in progeny liver tissues was verified by real-time fluorescent quantitative PCR.In the mouse liver cell line AML12,LncRNA and downstream microRNA were separately interfered by SiRNA,and the functions of LncRNA and downstream targets were verified by real-time fluorescent quantitative PCR and oil red O staining.Results: Compared with the control group,the offspring of obese mothers showed low birth weight,and the female offspring of obese mothers showed an overweight trend within 8 weeks after birth.The female progeny of obese mothers had higher triglyceride levels at 8 weeks of age than the control female offspring.We identified 4393 LncRNAs from the total RNA library,3226 are known genes,and 1167 are unknown genes.The genomic loci of the identified LncRNA are widely distributed on chromosomes other than the Y chromosome.By DEseq differential analysis,we found 37 up-regulated and 47 down-regulated known LncRNAs.According to the difference score,LncRNA Lockd was selected as the gene with the greatest difference in expression.LncRNA Lockd is located in the cytoplasm of the cell and is located on chromosome 6.The downstream target of LncRNA Lockd was predicted to be miR-582-5p by the online site,and the downstream target of miR-582-5p was Elovl5.Functional enrichment analysis revealed that "fatty acid metabolism" is the most significantly enriched pathway and is associated with lipid metabolism.It was confirmed by experiments that the expression of LncRNA Lockd and Elovl5 was down-regulated and the expression of miR-582-5p was up-regulated in obese female progeny.AML12 cells were treated with 0.1 mmol/L palmitic acid(PA)for 24 h to simulate liver lipid deposition in vitro.Interference with LncRNA Lockd was observed by SiRNA,miR-582-5p expression was up-regulated,Elovl5 expression was down-regulated,and cell lipid deposition was increased.Interference with miR-582-5p by SiRNA,LncRNA Lockd expression was not affected,Elovl5 expression was upregulated,and cell lipid deposition was reduced.Conclusion: LncRNA Lockd may be a key gene in the disorder of hepatic lipid metabolism in the offspring caused by maternal obesity.LncRNA Lockd acts as an endogenous RNA to compete with Elovl5 for binding to miR-582-5p,resulting in lipid deposition in the liver of the offspring.