Toxoplasma ROP16(I/III) ameliorated inflammatory bowel diseases via inducing M2 phenotype of macrophages.

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. To explore the beneficial effect of ToxoROP16I/III-induced M2 phynotype macrophages in homeostasis of IBDs through downregulation of M1 inflammatory cells. 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 ToxoROP16I/III was observed in RAW264.7 macrophages that were transfected with pEGFP-rop16 I/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 (iNOS), and arginase-1 (Arg-1) was detected. The expression of iNOS, Arg-1, signal transducer and activator of transcription 3 (Stat3), p-Stat3, Stat6, p-Stat6, 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. M1 cells exhibited significantly increased production of iNOS, NO, TNF-α, IL-1β, and IL-6, while ToxoROP16I/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 ToxoROP16I/III exhibited decreased production of NO and iNOS 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. ToxoROP16I/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.

Xu YW ，Xing RX ，Zhang WH ，Li L ，Wu Y ，Hu J ，Wang C ，Luo QL ，Shen JL ，Chen X ... -  《-》

The pentacyclic triterpene Lupeol switches M1 macrophages to M2 and ameliorates experimental inflammatory bowel disease.

Inflammatory bowel disease (IBD), including ulcerative colitis and Crohn's disease, is a chronic inflammatory disease in the lower gastrointestinal tract. Mounting evidence suggests that the predominance of the classically activated (M1) macrophages versus the alternatively activated (M2) macrophages plays a role in the progression of IBD. Thus, agents able to shift pro-inflammatory M1 macrophages to anti-inflammatory M2 macrophages may be beneficial to IBD. The pentacyclic triterpene Lup-20(29)-en-3β-ol (Lupeol), a potent anti-inflammatory natural product, has been shown to inhibit pro-inflammatory cytokine production, suggesting it is potentially able to modulate macrophage polarization, thereby beneficial to IBD. CD4(+) monocytes were differentiated to M1 or M2 macrophages, which were cocultured with epithelial cell lines, T84 and Caco-2, in the absence or presence of Lupeol (10μM). Experimental colitis was induced with dextran sodium sulfate (DSS), with or without oral administration of Lupeol (50mg/kg, q.d.). Cytokines were measured with Luminex kits. M1/M2 genes were measured with real-time polymerase chain reaction. Macrophage phenotypes were defined by measuring M1 and M2 markers with confocal microscopy. Proteins were measured with Western blotting, while cell surface markers were measured with confocal microscopy or flow cytometry. Histology was evaluated with H&E staining. Treatment of M1 macrophages with Lupeol resulted in a marked decrease in the production of pro-inflammatory cytokines, including IL-12, IL6, IL-1β and TNFα, and a marked increase in the production of IL-10, an anti-inflammatory cytokine. This was associated with a down-regulation of CD86, a typical marker of M1 macrophages, and an up-regulation of CD206, a typical M2 macrophage marker. IRF5, a transcription factor that is critically involved in M1 polarization, was down-regulated in M1 macrophages after being incubated with Lupeol, associated with a marked decrease in the phosphorylation of p38 mitogen activated protein kinase. Coculture of epithelial cells with M1 macrophages resulted in down-regulation of the tight junction protein ZO-1 and disruption of epithelial integrity, which were blocked by Lupeol treatment of the M1 macrophages. Moreover, oral administration of Lupeol to dextran sulfate sodium (DSS)-induced colitis mice resulted in mitigated intestinal inflammation and increased survival from lethal colitis, associated with decreased expression of M1-related genes and increased expression of M2-related genes. Lupeol ameliorates experimental inflammatory bowel disease through, at least in part, inhibiting M1 and promoting M2 macrophages.

Zhu Y ，Li X ，Chen J ，Chen T ，Shi Z ，Lei M ，Zhang Y ，Bai P ，Li Y ，Fei X ... -  《-》

Pyropia yezoensis glycoprotein promotes the M1 to M2 macrophage phenotypic switch via the STAT3 and STAT6 transcription factors.

Choi JW ，Kwon MJ ，Kim IH ，Kim YM ，Lee MK ，Nam TJ ... -  《-》

C16, a novel sinomenine derivatives, promoted macrophage reprogramming toward M2-like phenotype and protected mice from endotoxemia.

Ni P ，Liu YQ ，Man JY ，Li W ，Xue SS ，Lu TH ，Su ZL ，Zhou CL ... -  《-》

[Adipose-derived stem cells promote the polarization from M1 macrophages to M2 macrophages].

Yin X ，Pang C ，Bai L ，Zhang Y ，Geng L ... -  《-》