Inhibitory effect of Polygonatum sibiricum polysaccharides on release of inflammatory cytokines of anoxia/reoxygenation H9c2 myocardial cells through TLR4-MyD88-NF-κB signaling pathway / 中国药理学通报

ABSTRACT

Aim To assess the regulatory effects of Po-lygonatum sibiricum polysaccharides(PSP)on Toll-like receptor 4 (TLR4 )-myeloid differentiation factor 88 (MyD88)-nuclear factor κB(NF-κB)signaling path-way in anoxia /reoxygenation-H9c2 myocardial cells. Methods The H9c2 myocardial cells cultured in vitro were randomly divided into groupscontrol group (C group),hypoxia /reoxygenation group (H/R group), PSP group,TLR4 inhibitor group(TAK-242 group)and PSP +TLR4 inhibitor group(PSP +TAK-242 group). The cells were cultured in normal condition for 27 h in C group.The cells were subjected to 21 h hypoxia fol-lowed by 6 h reoxygenation in H/R.Definitely,the cells in TAK-242,PSP and PSP +TAK-242 groups were treated with PSP and TAK-242 with the final con-centration of 1 .5 g·L -1 and 1 μmol·L -1 for 1 2 h before 21 h hypoxia,then the cells were exposed to the normal culture condition for another 6 h.After the treatment,cell survival rate was tested by MTT method. The contents of tumor necrosis factor-α(TNF-α)and interleukin-1 β(IL-1 β)were determined by enzyme-linked immunosorbent assay(ELISA).The protein ex-pression levels of NF-κB and inhibitor κBα(IκBα) were detected by Western blot,and the expression lev-els of TLR4 and MyD88 mRNA were detected by fluo-rescence quantitative PCR method.Results Compared with H/R group,the cell survival rates were significant-ly increased,while the inflammatory cytokines contents and NF-κB protein expression were dramatically de-creased in groups PSP,TAK-242 and PSP +TAK-242, whereas the NF-κB expression was significantly down-regulated,and the IκBα protein expression was in-creased.The mRNA expression levels of TLR4 and MyD88 were markedly decreased.Conclusion PSP might protect H9c2 myocardial cells against H/R inju-ry,which may be associated with the inhibition of TLR4-MyD88-NF-κB pathway.