RESUMO
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.
RESUMO
To investigate the regulation of osteoclast inhibitory lectin (OCIL) mRNA expression by prostaglandin E2 ( PGE2 ) in rat osteoblastic cells and the involved signaling pathways. Rat primary osteoblasts and UMR106 osteoblast-like cells were cultured and treated with various doses of PGE2 or regulators of different signaling pathways for different periods of time, the cells were then harvested at indicated dates. Total RNA were isolated and OCIL mRNA expression were studied by real-time PCR. PGE2, Forskolin, db-cAMP, and A23187 increased OCIL mRNA by 2. 38 fold,4. 2 fold,4. 5 fold, and 5. 1 fold ( all P＜0. 01 ) respectively, while PMA downregulated OCIL mRNA expression by 50% ( P＜0. 01 ). KT-5720, verapamil, W7, and PD98059 downregulated PGE2 induced OCIL mRNA expression by 56%, 40%, 65%, and 60%, respectively( all P＜0. 0l ). While chelerythrine enhanced PGE2 induced OCIL mRNA expression by 30% ( P＜0. 05 ). PGE2 up-regulated the expression of OCIL in rat osteoblastic cells via PKA, MAPK, and Ca2+/Calmodulin signaling pathways.