| Dietary Restriction,defined as food intake reduces 20%-40%under conditions that do not lead to malnutrition.At present,DR experiments have been carried out on many model organisms,such as elegans,fruit fly,fish,rodents,which proved that dietary restriction can delay the aging and diseases effectively,also improve the healthspan of the elderly.The mechanisms of dietary restriction which involving many molecular signaling pathways are complex.One of the mechanisms is dietary restriction can effectively resist oxidation and antagonize diseases which induced by oxidation.Across to inhibite oxidative stress,dietary restriction helps cell to maintain an appropriate redox state and reduce the level of inflammation,thereby prolonging life.Although there are many theoretical hypotheses to explain the mechanisms of prolonging lifespan,they still need to be confirmed and perfected.In this study,we used classical model Drosophila melanogaster to sequencing protein,and tried to explore mechanisms of dietary restriction prolonging lifespan.Experiment sets up two groups:dietary restriction group and control group.The samples were collected on 7th day and the 42nd day.The samples were sequenced by isobaric tags for relative and absolute quantification(iTRAQ)technique.Using Uniport Drosophila melanogaster database,finally identify 19730 unique peptides which corresponding to 3662 proteins.The 7d restriction group/control group for 383 differentially expressed proteins,156 up-regulated proteins,227 down regulated proteins;42d restriction group/control group for 409 differentially expressed proteins,206 up-regulated proteins,203 down regulated proteins.GO,KEGG and PPI were used to further analyze the sequencing results.The conclusions are as follows:1.Bioinformatics analysis showed that the pathways closely related to dietary restriction,such as MAPK,mTOR,IRS and so on,appeared in the differential protein analysis data.2.DR is related to histone acetylation which regulated by sirtuin.Under dietary restriction,the level of DNA methylation decreased.The results of GO analysis in this experiment show dietary restriction may related to ubiquitination except methylation and acetylation.Especially in 7d DR gourp vs control group comparison,the degree of ubiquitination was not significantly different,However,in the 42d DR group vs control group,both the GO analysis results and KEGG pathway results showed that differential express proteins were involved in a higher level of ubiquitination.This is a new evidence for the epigenetic modifications by DR.3.The experimental results show that the restriction of food intake may regulate the activity or function of the spliceosome to inhibit the occurrence of the disease,so as to improve the health level of the body.The levels of differentially expressed proteins involved in the splicing pathway were significantly increased in 7d and 42d,which was consistent with the results of the study of the improvement of the health level of each age group.4.Riboflavin is an integral part of the enzymes in the body,which is responsible for providing hydrogen ions in the redox reaction.In the KEGG results,the concentration of riboflavin in 42d group was significantly higher than that in the control group.After aging,the storage capacity of riboflavin in the body decreased significantly.Dietary restriction can enhance riboflavin metabolism,thus ensuring the amount of riboflavin in the redox reaction.5.KEGG pathway enrichment revealed that a number of differentially expressed proteins are involved in the pathogenesis of Alzheimer’s disease,Parkinson’s syndrome,and Huntington’s diseases,three classic neurodegenerative diseases.Among them,the differentially expressed protein P92208 also appeared in many diseases related pathways.These results suggest that P92208 may be a critical site for the regulation of food related diseases.6.Previous studies have found that the effect of dietary restriction is related to circadian rhythms.When the flies in addition to tim and per two key genes in the circadian clock,the restriction is no longer any effect.In this study,two circadian clock related proteins M9PC85 and 076879 were identified.However,the quantitative results showed that there was no significant up regulation or down regulation of the two proteins.This indicates that circadian clock has no direct effect on food restriction.7.Drosophila mTOR receptor can regulate immune function through HIPPO pathway.KEGG results showed that there were more than and 10 specific immune related pathways in 7d and 42d compared with the control group.Dietary restriction can improve the specific immunity level of the whole body and improve the health level of the whole body.8.We also found that pathway enrichment alos shows dietary restriction related to cytoskeleton and tubulin was significant.The results indicated that the effects of dietary restriction on the health and longevity of the body may be related to the changes of cytoskeleton... |
