TLR4mAb Inhibits The Endothelium-dependent Diastolic Function Of Mesenteric Arteries In Mice Injured By MmLDL

Purpose To investigate the role of toll like receptor 4 monoclonal antibodies(TLR4 mAb)in the endothelium-dependent relaxation of mesenteric artery in injury mice with minimally modified low density lipoprotein(mmLDL).Method The experimental mice were randomly divided into normal control group,model group,TLR4 mAb intervention group.The model group and the TLR4 mAb intervention group were injected with tail vein injection of mmLDL method.The TLR4 m Ab intervention group was given intraperitoneal injection of TLR4 mAb.The normal control group and the model group were injected with saline instead of TLR4 mAb intraperitoneally.The mice were sacrificed after 72 hours.Vascular systolic and diastolic function were measured by in vitro capillary trenching technique.Western blot and RT-PCR were used to detect the expression of protein and RNA,respectively.The levels of IL-1? and TNF-? in plasma were measured by ELISA The ultrastructure of mesenteric artery endothelial cells was observed by transmission electron microscopy.Results TLR4 mAb group significantly inhibited endothelium-dependent diastolic function of mesenteric arteries induced by mmLDL and inhibited the diminution of the diastolic function of NO-and EDHF-pathways induced by mmLDL.Among them,the EDHF pathway showed enhanced relaxation of KCa2.3 and KCa3.1 pathways,and KCa2.3 The mRNA expression of KCa3.1 and KCa3.1 was significantly higher than that of mmLDL group(P<0.05).TLR4 protein expression,phosphorylation levels of p-38 MAPK and NF-?B and concentrations of inflammatory cytokines IL-1? and TNF-? in the model group were significantly higher than those in the control group(P<0.05).In TLR4 mAb group,the expression of TLR4 and the level of inflammatory cytokines in serum were significantly lower than those in model group(P<0.05).Conclusion TLR4 mAb dose-dependently attenuated the impairment of endothelium-dependent diastolic function of mouse mesenteric arteries in a dose-dependent manner,attenuated the effects of the NOLD and EDHF pathways on mmLDL injury,and TLR4 mAb protected the KCa2.3 and KCa3.1 channels in the EDHF pathway.The mechanism may be related to the inhibition of TLR4 and downstream p-38 MAPK,NF-?B,and the decrease of inflammatory cytokines IL-1? and TNF-?.