An Analysis On Plasma Exosomes Metabolomics Of NAFLD Patients Complicated With Impaired Glucose Metabolism

Objective As one of the commonest liver diseases worldwide,non-alcoholic fatty liver disease(NAFLD)is closely associated with metabolic diseases,especially type 2 diabetes mellitus(DM).The aim of this study is to explore the different metabolites from plasma exosomes between patients with NAFLD alone and those with impaired glucose metabolism(IGM).Methods Ultrasonographically diagnosed adult patients with NAFLD in outpatient service,Xixi Hospital of Hangzhou,were enrolled.Subjects were devided into NAFLD group and NAFLD+IGM group according to the level of fasting glucose.Peripheral blood samples were collected,then were subjected to isolate exosomes by differential ultra-centrifugation.Exosomes were identified by transmission electron microscopy,diameter analysis and nano-flow cytometry.Ultra-high-performance liquid chromatography/quadrupole time-of-flight-tandem mass spectrometry(UHPLC-Q-TOF-MS/MS)was used to analyse the metabolites for both plasma and extracted exosomes.Differential metabolites were selected according to the value of variable importance in projection(VIP)of partial least squares discrimination analysis(PLS-DA),P value and fold-change(VIP>1,P<0.05,ratio>2 or<1/2).Metabolic pathway predictive analysis was performed online(www.metaboanalyst.ca).Results 1.A total of 39 patients were enrolled in this study,including NAFLD group(n=26)and NAFLD+IGM group(n=13).There were no statistically significant differences in age(23(26,31.5)vs 22(40,51.5)),BMI(28.68± 3.57 vs 30.65±5.85)and gender(M 22/26 vs 7/13)between the two groups.2.Metabolomic analysis of plasma between the group of NAFLD and NAFLD+IGM identified 41 metabolites,including fatty acids,glycerophospholipids,sterol lipids,carboxylic acids and derivatives,sphingolipids,naphthalenes,pregnenolones,keto acids and derivatives,benzene and substituted derivatives,piperidine,and so on.Two pathways,glycerophospholipid metabolism and glyceride metabolism,have been affected.3.Metabolomic analysis of exosomes between the two groups identified 10 metabolites,including fatty acids,glycerophospholipids,pregnenolones,benzene and substituted derivatives,etc.The pathway of linoleic acid metabolism has been affected.Conclusion The main metabolic characteristic profile in NAFLD patients with IGM demonstrated a significance of lipid molecules,especially the dysregulated pathway of linoleic acid in exosomes.Our study will benefit future exploration on the pathophysiology and novel therapeutics of NAFLD complicated with DM.