The Research Of Oxidative Stress Mechanism Of Linagliptin In RAW264.7 Cells Under Different Glucose Culture Conditions

ObjectiveThe incidence of diabetes risen perpetually and the organisation of diabetic patients with acute gastric ulcers caused by Nonsteroidal Antiinflammatory Drugs(NSAIDs)is a huge community.The healing of gastric ulcer in patients with diabetes is more difficult than normal patients.In recent years,many studies have proved that Dipeptidyl Peptidase 4(DPP-4)inhibitors promote diabetic wound healing by anti-inflammatory and oxidant ect.The aims of research are to explore the effect and mechanism of linagliptin on diabetes with acute gastric ulcer in vitro.MethodsIt is divided into normal glucose group and high glucose group according to the glucose concentration of the cell culture medium,The group is divided into control group and experimental groups according to the linagliptin concentration in different glucose concentration glucose: normal glucose group(control group: normal glucose +phosphate balanced solution(PBS);Experimental group: normal glucose+10NM(NM=nmol/L,the same below)linagliptin,normal glucose+40NM linagliptin,normal glucose+50NM linagliptin,normal glucose+100NM linagliptin,normal glucose+200NM linagliptin),high-glucose group(control group: high-glucose+PBS;experimental group: high-glucose+10NM linagliptin,high-glucose +40NM linagliptin,high-glucose +50NM linagliptin,high glucose + 100 NM linagliptin,high glucose +200NM linagliptin).RAW264.7 cells were cultured and stimulated in the above groups.After incubating for 1 hour at 37°C,Lipopolysaccharides(LPS,concentration of0.5ug/ml)were added and incubated for 24 hours.The cells were collected for Polymerase Chain Reaction.The m RNA expression of superoxide dismutase(SOD),catalase(CAT)and interleukin-6(IL-6)in cells.-6),Tumor Necrosis Factor α(TNF-α)are measured by Quantitative real time polymerase chain reaction(q-PCR).Statistical analyses were performed by SPSS Statistics 22.0 and the figures were performed by Graph Pad Prism 5.0.Values were considered significant at the P< 0.05 level.Results1.In the control group,the high glucose inhibited the expression of CAT,SOD and IL-6 m RNA in RAW 264.7 cells and promoted the expression of TNF-α compared with the normal glucose group,the difference was statistically significant(P<0.05).2.In the normal glucose group,the concentration of linagliptin at 40 NM,50NM and200 NM promoted the expression of CAT m RNA in RAW 264.7 cells compared with the control group,and the expression of CAT m RNA was the highest at the concentration of 200NM(P<0.05).3.In the high glucose group,concentrations of linagliptin at 40 NM,50NM,100 NM,200NM promoted the expression of CAT m RNA in RAW 264.7 cells compared with the control group,and the effect was strongest at the concentration of 100NM(P<0.05).4.In the normal glucose group,compared with the control group,the concentration of linagliptin at 50 NM and 100 NM promoted the expression of SOD in RAW 264.7cells(P<0.05),and the concentration of linagliptin at 10 NM and 200 NM inhibited RAW 264.7 SOD m RNA expression in cells(P<0.05).5.In the high glucose group,linagliptin concentrations of 40NM、50NM、100NM,and 200 NM promoted the expression of SOD m RNA in RAW 264.7 cells compared with the control group,and the effect was the strongest at a concentration of 40NM(P<0.05).6.In the normal glucose group,all concentrations of linagliptin inhibited the expression of IL-6 m RNA in RAW 264.7 cells,and the inhibitory effect was the strongest at a concentration of 100NM(P<0.05).7.In the high glucose group,compared with the control group,linagliptin concentrations of 10 NM,100NM and 200 NM inhibited the expression of IL-6 m RNA in RAW 264.7 cells,and the inhibitory effect was the strongest at 200NM(P<0.05).Linagliptin concentration of 40 NM and 50 NM promoted the expression of IL-6 m RNA in RAW 264.7 cells(P<0.05).8.In the normal glucose group,all concentrations of linagliptin promoted the expression of TNF-α m RNA in RAW 264.7 cells compared with the control group,and the difference was statistically significant at concentration of 40 NM and 50NM(P<0.05);Compared with the concentration of 10 NM,the expression of TNF-α was higher at the concentration of 40 and 50NM(P<0.05);compared with the concentration of 40 NM,the expression of TNF-α was lower at the concentration of 100 and 200NM(P<0.05);compared with the concentration of 50 NM,the expression of TNF-α was lower at the concentration of 100NM(P<0.05).9.In the high glucose group,all concentrations of linagliptin promoted the expression of TNF-α m RNA in RAW 264.7 cells compared with the control group,and the difference was statistically significant at the concentration of 100 NM and 200 NM,and at the concentration of 200 NM The promotion effect is the strongest at the time(P<0.05).conclusion1.In high glucose state,the expression of anti-oxidative stress factors(SOD,CAT)were inhibited,and the expression of inflammatory factor TNF-α was up-regulated in vitro,which destroyed the antioxidant system in cells.2.Linagliptin promoted the expression of SOD and CAT,inhibited the expression of IL-6 in vitro,which reduced oxidative stress,enhanced the ability of scavenging oxygen free radicals,and inhibited the release of inflammatory factors.It was effective to protect cells from damage of high glucose by anti-oxidative stress.