The effects of lymph after intestinal ischemia/reperfusion on the inflammatory factors and Toll-like receptor 4 ligand high mobility group box-1 in Toll-like receptor 4 deficient mice / 中华临床营养杂志

ABSTRACT

Objective To investigate the effects of lymph from ischemic/reperfused intestine on the inflammatory factors and Toll-like receptor 4 (TLR4) ligand high mobility group box-1 (HMGB1) in TLR4 deficient (TLR4-/-) mice.Methods A total of 20 SD rats weighing (300 ±20) g were randomly assigned into two groupslymph drainage group (group N,lymph drainage for 180 minutes without other treatment) and intestinal ischemia/reperfusion group (group I/R,draining the lymph for 180 minutes while clipping the superiormesenteric artery for 60 minutes followed by 120-minute reperfusion).Thirty-two TLR4-/-mice and thirty-two C57BL/6 wild type (WT) mice were each divided into 4 sub-groups (n =8),injected with different fluids through the caudal veingroup N with normal lymph;group I/R with I/R lymph;group Edt with endotoxin;group HMGB1 with HMGB1 protein.The mice were sacrificed 180 minutes after the injection for sample collection.Results The levels of endotoxin and HMGB1 in the lymph drainage of the group I/R rats were significantly higher than that of the group N rats [(0.034 ± 0.050) Eu/ml vs.(0.017 ± 0.023) Eu/ml,P =0.033;(4.293 ± 0.883) ng/ml vs.(0.509 ± 0.128) ng/ml,P =0.006].In the mice injected with HMGB1,the mucosa thickness and villus height in the ileum of the WT mice were significantly lower than that of the TLR4-/-mice [(335.8±43.2) μmvs.(602.1±37.5) μm,P=0.000;(273.0±31.7) μm vs.(404.5 ± 18.6) μm,P =0.000];in both WT and TLR4-/-mice injected with the I/R lymph drainage,the mucosa thickness and virus height were decreased,but the decrements were significantly lower in TLR4-/-mice;there were no statistically significant differences in the levels of interleukin-6 (IL-6),tumor necrosis factor-α (TNF-α),endotoxin,and HMGB1 between the TLR4-/-and the WT mice injected with normal lymph or endotoxin.In the mice injected with I/R lymph drainage,the levels of inflammatory factors in the TLR4-/-mice were significantly lower than those in the WT mice [TNF-α(28.637 ±5.166) pg/ml vs.(41.917 ±8.175) pg/ml,P=0.000;IL-6(60.900 ±24.729) pg/ml vs.(110.265 ±28.545) pg/ml,P =0.000].In the mice injected with HMGB1,the levels of inflammatory factors in the TLR4-/-mice were significantly decreased compared with those in the WT mice [TNF-α(20.865 ± 6.464) pg/ml vs.(31.059 ± 6.204) pg/ml,P=0.004;IL-6(36.268 ±8.977) pg/ml vs.(76.677 ± 14.099) pg/ml,P=0.000].Conclusions The concentrations of endotoxin and HMGB1 are significantly increased during intestinal I/R in rats.After injection of I/R lymph drainage,endotoxin,and HMGB1,the levels of inflammatory factors and HMGB1 in the mice injected with I/R lymph drainage are significantly higher than those in the mice injected with normal lymph;the levels of inflammatory factors and local damage of intestinal mucosa are significantly reduced in the TLR4-/-mice than in the WT mice.The gut-lymph pathway may play a key role in the intestinal I/R injury.