Glutamin attenuates tumor necrosis factor-α release in lipopolysaccharide-induced alveolar type Ⅱepithelial cells / 中华急诊医学杂志

ABSTRACT

Objective To investigate the role of glutathione (GSH) synthesis in the regulation of Glutamine (Gin) on TNF-α release in lipopolysaccharide (LPS)-stimulated alveolar epithelial type Ⅱ cells (AEC Ⅱ). Method Primary cultured AECⅡ were divided into six groups, including control, 10.0 mmol/L Gln, 1 μg/mL LPS and LPS+(0.5, 2.0 and 10.0 mmol/L) Gln. In another set of experiments, AECⅡ were divided into six groups including 1 μg/mL LPS, LPS+10.0 mmol/L Gln, LPS+100 μmol/L L-buthionine-(S, R)-sulfoximine (BSO), LPS+Gln+(1,10 and 100 μmol/L) BSO. Each group had three samples. BSO and Gln were added at 8 hours before LPS challenge. After 24 hours of LPS stimulation, cells were obtained for GSH measurement by 5, 5'-dithiobis-(2-nitrobenzoic acid) (DTNB) method. TNF-α level in the supematant was determined by enzyme-hnked immunesorbent assay (ELISA). ANOVA (LSD-t test) was used for statistical analysis. Results Supple-mentation of Gin increased the GSH level and attenuated TNF-α release in LPS-stimulated AEC Ⅱ in a dose-depen-dam manner. GSH level increased from (50.69±3.04) pmol/mg cell (LPS group) to (126.74±7.13) pmol/mg cell (LPS+10.0 mmol/L group) (P<0.01) and TNF-α level decreased from (1104.5±48.8) pg/mL (LPS group) to (329.67±48.27) pg/mL (LPS+10.0 mmol/L group) (P<0.01). BSO, an GSH synthesis blocker, at doses greater than 10 μmol/L reversed the effect of Gin significantly (P<0.01). Conclusions As a precursor ofGSH, glutsmine could attenuate TNT-α release in LPS-stimulated AECⅡ,and the with may be mediated via GSH synthesis.