Crimycin Regulates Sepsis-induced Inflammatory Disorders And Its Mechanism

Sepsis,as a systemic syndrome accompanied by pathogen infection and immune disorders,is a major problem in the field of modern critical care medicine,and the research on inflammation-regulating drug treatments is currently a serious problem.Carrimycin(CA),as the first domestic class I new drug developed by synthetic biology technology in China,is a kind of acylated spiramycin mainly obtained by transforming spiramycin-producing bacteria through genetic engineering technology.At present,this new macrolide antibiotic has been approved by the National Medical Products Administration for the treatment of respiratory tract infections and infectious sinusitis,and has great potential for immunomodulatory functions.Therefore,the current study explored the therapeutic effect and the underlying mechanism of CA on sepsis by performing experiments using cell and sepsis mouse models.In the study,the inhibitory effects of CA and its monomers CA01 and CA03 on lipopolysaccharide(LPS)-induced inflammation in mouse macrophages were tested at the cellular level by CCK8,real-time PCR,ELISA and other methods.The data showed that10 μg/m L CA could effectively inhibit LPS-induced inflammation in mouse macrophages,and the inhibitory effect of CA01 and CA03 was not as obvious as that of CA.Next,we used transcriptome sequencing to further explore the mechanism by which CA exerts its anti-inflammatory effect.The results showed that the inhibition of LPS-stimulated inflammation in mouse macrophages by CA was related to NFκB,TNF,IL-17 and Toll-like receptor signaling pathways.It can reduce the expression of NFκB1,IL1β and IL6 genes.Immunofluorescence and Western blotting data show that CA can reduce the level of inflammation in mouse macrophages by inhibiting the nuclear translocation and phosphorylation of NFκB protein.At the animal level,we used LPS-treated,and cecal ligation and puncture(CLP)-induced sepsis mouse models to verify the protective effect of CA.After confirming that 100 mg/kg·d CA will not have obvious toxic and side effects on mice,we found that 100 mg/kg·d CA can prolong the survival rate of septic mice,help septic mice maintain a stable body temperature,reduce mice lung and liver inflammation levels and organ damage,reduce the expression of inflammatory factors in mouse serum.In addition,we found that CA can inhibit the expression of NK cells in LPS mice by flow cytometry,which indicates that CA may achieve immune regulation by regulating the expression of immune cells.In summary,we verified the inhibitory effect on inflammation and protective effect on sepsis mice from the cellular and animal levels,which is related to its regulation on inflammation and immunity through the NFκB pathway,and we found that CA has a certain effect on the expression of immune cells.This is the first time that CA has been used in the treatment of sepsis,which provides new evidence for the potential use of CA in treating sepsis and future therapeutic development.