Osteoclast inhibitory lectin related protein 2 protects mice from endotoxemia / 中华微生物学和免疫学杂志

ABSTRACT

Objecitv e To investigate the effects of a recombinant protein osteoclast inhibitory lectin related protein 2( OCILRP2)-Fc on LPS-induced endotoxemia by blocking OCILRP 2 signaling pathway and to in-vestigate the roles of OCILRP2 during inflammation.Methods Real-time PCR was used to detect OCILRP2 ex-pression at mRNA level in RAW264.7cells before and after in vitro stimulation with LPS.A mouse model of en-dotoxemia was established by intraperitoneal injection of BALB /c mice with a median lethal dose of LPS .Two hours prior to LPS treatment, mice were intraperitoneally injected with OCILRP2-Fc, human IgG or PBS, re-spectively .Several parameters including the survival rate of BALB/c mice with and without LPS treatment , spleen weight for arterial hyperemia analyzing , histopathological changes of lung and liver by HE staining , serum levels of inflammatory cytokines (IL-6, IL-12, TNF-αand IFN-γ)by ELISA , NF-κB activity by Western blot, were analyzed .Results Real-time PCR showed that LPS elevated in vitro OCILRP2 expression at mRNA level in macrophages (P<0.05).Upon the treatment of OCILRP2-Fc, BALB/c mice suffered from endotoxemia showed obviously increased survival rate , decreased spleen hyperemia , attenuated pathological injury of lung and liver, reduced levels of IL-6, IL-12, TNF-αand IFN-γin serum samples (P <0.05) as compared with mice treated with human IgG and PBS .LPS induced NF-κB p65 phosphorylation and IκB degradation were inhibited by OCILRP2-Fc treatment.Conclusion OCILRP2-Fc protects mice from endotoxemia by blocking OCILRP 2 signaling, which suggests that OCILRP2 plays an important role in LPS induced inflammation.