Effects of high glucose on inflammatory cytokine expressions in human gingival epithelial cells stimulated by lipopolysaccharide

Objective To investigate the effects of high glucose on expressions of inflammatory cytokines in human gingival epithelial cells( HGECs) stimulated by lipopolysaccharide( LPS).Methods Primary HGECs were cultured in vitro and the 3rdgeneration cells were harvested.The cells were assigned to high glucose group( 25 mmol / L D-glucose)and control group( 5.5 mmol / L D-glucose).Each group was divided into 4 sub-groups after 48 h culture,which were treated with LPS at different concentrations respectively( 0 μg / m L,1 μg / m L,5 μg / m L and 10 μg / m L).Real-time quantitative PCR( RT-PCR) was applied to detect the expressions of gene [interleukin-6( IL-6),interleukin-1β( IL-1β),interleukin-8( IL-8) ]levels,and the expressions of IL-8 in cell culture supernatant at 2 h,4 h and 8 h after LPS stimulation was detected by ELISA.Results After stimulation by 5μg / m L LPS for 8 h,the transcription levels of inflammatory factors in high glucose group were significantly higher than that of control group,showing as IL-6( 13.20 ±0.84 and 8.85 ± 0.53,t = 7.60,P = 0.002),IL-8( 14.88 ± 1.54 and 8.12 ± 0.46,t = 7.281,P = 0.002),and IL-1β( 1.69 ± 0.19 and 1.27 ± 0.11,t = 3.348,P = 0.029).In addition,the level of IL-8 in culture supernatant of high glucose group was significantly increased compared with control group( 134.0 ± 10.8 pg / m L and 103.0 ± 11.0 pg / m L,t = 3.480,P = 0.025).Conclusion High glucose might promote the expressions of inflammatory cytokines in HGECs stimulated by LPS,such as IL-6,IL-8,IL-1β.