Metabonomic Study On Serum And Gingival Crevicular Fluid Of Periodontitis

OBJECTIVE:The purpose of this study is to screen specific metabolic markers of chronic periodontitis(CP)and aggressive periodontitis(Ag P)using gas chromatography-mass spectrometry(GC-MS)of serum and gingival crevicular fluid,and to establish a data model.The study will provide a new theoretical basis for the pathogenesis and early diagnosis of periodontitis.METHODS:The serum and gingival crevicular fluid samples were collected from 20 patients with severe CP,20 patients with Ag P and 20 healthy controls from Department of Periodontology,Ninth People’s Hospital,Shanghai Jiao Tong University School of Medicine.The samples were treated with 1%trimethylsilane-N-O-bis-tri-fluoroacetamide for derivatization,then analyzed by GC-MS analysis.PCA and OPLS-DA were used to screen the main different metabolites for effectively characterizing.These biomarkers were identified by the Fiehn database.RESULTS:(1)The serum samples of three groups were analyzed by GC-MS.200 endogenous metabolites were detected.An unsupervised PCA data showedthat there were significant differences in the metabolic patterns among the three groups.OPLS-DA analysis indicated that the levels of glutathione,norepinephrine renin,2,5-dihydroxybenzaldehyde and 2’-deoxyguanosine were significantly lower in patients with CP and Ag P compared with healthy controls.However,urea and iso-inositol are higher than those in control group.These metabolites are mainly associated with oxidative stress,purine metabolism and tyrosine metabolism.However,there is no significant difference between CP and Ag P group.(2)The GCF was analyzed by GC-MS.349 endogenous metabolites were identified.OPLS-DA analysis showed that the content of glutathione and thymidine in patients with periodontitis was lower than that in the healthy controls.The lever of xanthine,dehydroascorbic acid,vitamin E,β-alanine,uridine and malonate are higher than those in control group.These metabolites maybe related to oxidative stress and pyrimidine metabolism.In the control group,5-phosphogluconate and glucose phosphate was lower than that in Ag P group.However,glucuronic acid,5-phosphogluconate and fructose-6-phosphate were lower compared with CP.Furthermore,the levels of glucuronic acid,fructose-6-phosphate,fructose-1,6-diphosphate and5-phosphogluconate in the Ag P group was lower than those in CP group.It may resulted by different pathogenic bacteria.CONCLUSION:(1)GC-MS analysis is suitable for metabonomics of serum and GCF among CP patients,Ag P patients and healthy controls.(2)The different metabolites selected in this study may be potential biomarkers of CP and Ag P.(3)Oxidative stress,tyrosine metabolism,purine metabolism and pyrimidine metabolism have a certain relationship with periodontal inflammation.There are different glucose metabolisms between the two kinds of periodontitis.The differences may be related to different periodontal pathogens and its metabolic activity.