Influence Of Remnant-like Particles On Adipose Mesenchymal Stem Cells Adipogenic Differentiation

BackgroundThe occurrence of obesity was due to adipocyte hypertrophy(increase in size) alone.Now it is recognized that obesity is also induced by the adipocyte hyperplasia(increase in number) in adipose tissue.The adipose-derived mesenchymal stem cells(ADSCs) is an important source of adipocyte differentiation and renewal.Obesity usually coexists with hypertriglyceridemia which represents the increased triglyceride-rich lipoproteins and their metabolic products,remnant-like particles(RLPs) in circulation.It was demonstrated that very low density lipoprotein (VLDL),one constitutent of triglyceride-rich lipoproteins,can induce bone marrow-derived mesenchymal stem cells and 3T3-L1 preadipocyte cells to differentiate into adipocytes in a apolipoprotein E (ApoE)-dependent manner.It is conjectured that RLPs,who containing more ApoE,could induce ADSCs to differentiate into adipocytes.ObjectiveTo explore the effects of defferent concentrations of RLPs on the adipogenic differentiation of ADSCs.MethodsCollagenase typeⅠwas used to isolate ADSCs from inguinal adipose tissue of SD male rats.These cells were cultured and passaged in culture medium which contained DMEM/F12 supplemented with 10%FBS. After stimulation by standard inducer which containing 3-isobutyl-1-methylxanthine,dexamethasone,and 10μg/ml insulin,the morphological changes of ADSCs was observed under optical microscope.Lipid droplets within cells were identify by Oil red O staining.Taking ADSCs stimulated by 10μg/mL insulin as the control group,stimulated by RLPs were divided into three groups according to RLPs concentration(50μg/mL RLPs+10μg/mL insulin,100μg/mL RLPs+10μg/mL insulin and 200μg/mL RLPs+10μg/mL insulin).After 18 days,four groups of ADSCs were observed under optical microscope and stained by Oil red O.ResultsSpindle ADSCs grew in a manner like fibroblasts grewing and can stably proliferate in DMEM/F12 culture medium.After stimulation by standard inducer,spindle ADSCs became bigger and rounder in shape and lipid droplet emerged within cells.They were confirmed as matured adipocytes by Oil red O staining.Undering the stimulation of insulin (10μg/ml) and RLPs,different groups have different Oil red O coloring intensity appearances.The group stimulated by 100μg/ml RLPs haD stronger oil red O coloring intensity than that by 50μg/ml RLPs(P＜0.05), the group stimulated by 200μg/ml RLPs had stronger oil red O coloring intensity than other three groups(P＜0.05).There was no significant difference in oil red O staining intensity between the group stimulated by 50μg/ml RLPs and the control group.ConclusionsRLPs induce ADSCs to differentiate into adipocytes in a concentration-dependent manner.