BACKGROUND Inflammatory bowel disease（IBD） is characterized by chronic and non-specific inflammation of the intestinal mucosa and mainly includes ulcerative colitis and Crohn’s disease.AIM To explore the beneficial...BACKGROUND Inflammatory bowel disease（IBD） is characterized by chronic and non-specific inflammation of the intestinal mucosa and mainly includes ulcerative colitis and Crohn’s disease.AIM To explore the beneficial effect of Toxo ROP16Ⅰ/Ⅲ-induced M2 phynotype macrophages in homeostasis of IBDs through downregulation of M1 inflammatory cells.METHODS RAW264.7 macrophages stimulated by lipopolysaccharide（LPS）（M1 cells） were co-cultured with Caco-2 cells as an inflammatory model of IBD in vitro.The expression of Toxo ROP16Ⅰ/Ⅲ was observed in RAW264.7 macrophages that were transfected with p EGFP-rop16Ⅰ/Ⅲ.The phenotypes of M2 and M1 macrophage cells were assessed by quantitative real-time reverse transcriptase polymerase chain reaction and the expression of tumor necrosis factor（TNF）-α,interleukin（IL）-1β,IL-6,transforming growth factor（TGF）-β1,IL-10,inducible nitric oxide synthase（i NOS）,and arginase-1（Arg-1） was detected.The expression of i NOS,Arg-1,signal transducer and activator of transcription 3（Stat3）,p-Stat3,Stat6,pStat6,programmed death ligand-2（PD-L2）,caspase-3,-8,and-9 was analyzed by Western blotting,and Griess assays were performed to detect nitric oxide（NO）.TNF-α,IL-1β,IL-6,TGF-β1,and IL-10 expression in the supernatants was detected by enzyme-linked immunosorbent assay,and Caco-2 cell apoptosis was determined by flow cytometry after mixing M1 cells with M2 cells in a Caco-2 cell co-culture system.RESULTS M1 cells exhibited significantly increased production of i NOS,NO,TNF-α,IL-1β,and IL-6,while Toxo ROP16Ⅰ/Ⅲ induced macrophage bias to M2 cells in vitro,showing increased expression of Arg-1,IL-10 and TGF-β1 and elevated production of p-Stat3 and p-Stat6.The mixed M1 and M2 cell culture induced by Toxo ROP16 Ⅰ/Ⅲ exhibited decreased production of NO and i NOS and upregulated expression of Arg-1 and PD-L2.Accordingly,Caco-2 cells became apoptotic,and apoptosis-associated proteins such as caspase-3,-8 and-9 were dampened during co-culture of M1 and M2 cells.Flow cytometry analysis showed that co-culture of M1 cells with Caco-2 cells facilitated the apoptosis of Caco-2 cells,but co-culture of M1 and M2 cells alleviated Caco-2 cell apoptosis.CONCLUSION Toxo ROP16 Ⅰ/Ⅲ-induced M2 macrophages inhibited apoptosis of Caco-2 cells caused by M1 macrophages.This finding may help gain a better understanding of the underlying mechanism and represent a promising therapeutic strategy for IBDs.展开更多
基金Supported by the National Natural Science Foundation of China,No.81471983the Key Research and Development Plan Project of Anhui Province,Department of Science and Technology 2019,No.201904a07020043+1 种基金the Key Project of Natural Science Research in the Universities of Anhui Provence,No.KJ2017A202the Research Fund Project of Anhui Institute of Transforming Medicine,No.2017zhyx04
文摘BACKGROUND Inflammatory bowel disease（IBD） is characterized by chronic and non-specific inflammation of the intestinal mucosa and mainly includes ulcerative colitis and Crohn’s disease.AIM To explore the beneficial effect of Toxo ROP16Ⅰ/Ⅲ-induced M2 phynotype macrophages in homeostasis of IBDs through downregulation of M1 inflammatory cells.METHODS RAW264.7 macrophages stimulated by lipopolysaccharide（LPS）（M1 cells） were co-cultured with Caco-2 cells as an inflammatory model of IBD in vitro.The expression of Toxo ROP16Ⅰ/Ⅲ was observed in RAW264.7 macrophages that were transfected with p EGFP-rop16Ⅰ/Ⅲ.The phenotypes of M2 and M1 macrophage cells were assessed by quantitative real-time reverse transcriptase polymerase chain reaction and the expression of tumor necrosis factor（TNF）-α,interleukin（IL）-1β,IL-6,transforming growth factor（TGF）-β1,IL-10,inducible nitric oxide synthase（i NOS）,and arginase-1（Arg-1） was detected.The expression of i NOS,Arg-1,signal transducer and activator of transcription 3（Stat3）,p-Stat3,Stat6,pStat6,programmed death ligand-2（PD-L2）,caspase-3,-8,and-9 was analyzed by Western blotting,and Griess assays were performed to detect nitric oxide（NO）.TNF-α,IL-1β,IL-6,TGF-β1,and IL-10 expression in the supernatants was detected by enzyme-linked immunosorbent assay,and Caco-2 cell apoptosis was determined by flow cytometry after mixing M1 cells with M2 cells in a Caco-2 cell co-culture system.RESULTS M1 cells exhibited significantly increased production of i NOS,NO,TNF-α,IL-1β,and IL-6,while Toxo ROP16Ⅰ/Ⅲ induced macrophage bias to M2 cells in vitro,showing increased expression of Arg-1,IL-10 and TGF-β1 and elevated production of p-Stat3 and p-Stat6.The mixed M1 and M2 cell culture induced by Toxo ROP16 Ⅰ/Ⅲ exhibited decreased production of NO and i NOS and upregulated expression of Arg-1 and PD-L2.Accordingly,Caco-2 cells became apoptotic,and apoptosis-associated proteins such as caspase-3,-8 and-9 were dampened during co-culture of M1 and M2 cells.Flow cytometry analysis showed that co-culture of M1 cells with Caco-2 cells facilitated the apoptosis of Caco-2 cells,but co-culture of M1 and M2 cells alleviated Caco-2 cell apoptosis.CONCLUSION Toxo ROP16 Ⅰ/Ⅲ-induced M2 macrophages inhibited apoptosis of Caco-2 cells caused by M1 macrophages.This finding may help gain a better understanding of the underlying mechanism and represent a promising therapeutic strategy for IBDs.
