Luteolin regulates M1 macrophage polarization by inhibiting glycolytic pathway induced by HIF-1 / 中国药理学通报

Aim To investigate the effect of luteolin on M1 macrophages polarization through HIF-1α-mediated glycolytic pathway. Methods RAW264.7 cells were divided into control groups(M0)and LPS+IFN-γ groups(M1). M1 groups were further divided into luteolin group, 2-DG(glycolysis inhibitor)group, luteolin+2-DG group,luteolin+DMOG(HIF-1α agonist)group. The protein expression levels of iNOS, Arg-1 and HIF-1α were detected by Western blot. Macrophage phenotype was detected by flow cytometry. In addition, the expression levels of IL-6 and IL-10 were measured by ELISA. The gene expression levels of GLUT1, HK2, PFK1, PK and HIF-1α were quantified by quantitative real-time PCR. Results Compared with M1 groups, luteolin and luteolin+2-DG treatment groups decreased the expression levels of GLUT1, HK2, PFK1, PK and HIF-1α related to glycolysis. In addition, luteolin and luteolin+2-DG treatment group significantly inhibited the expression of M1 macrophage markers such as iNOS, CD86 and IL-6, whereas up-regulated M2 macrophage markers Arg-1, CD206 and IL-10. Notably, the inhibitory effects of luteolin on M1 macrophages were restored by DMOG. Conclusion Luteolin regulates M1 macrophage polarization by inhibiting the glycolytic pathway induced by HIF-1α.

Therapeutic effects of hypoxia-inducible factor-1α siRNA on collagen-induced arthritis in mice and its inhibitory effects on M1 macrophages / 中华微生物学和免疫学杂志

Objective:To investigate the therapeutic effects of a small interfering RNA (siRNA) targeting hypoxia inducible factor-1α (HIF-1α) on collagen-induced arthritis (CIA) in mice and to analyze the possible mechanism at the macrophage level.Methods:DBA/1 mice were injected with bovine type Ⅱ collagen to establish the CIA model. Then, they were injected with HIF-1α-siRNA adenovirus or negative control adenovirus through tail vein once a week for four weeks. This study included four groups: control group, CIA model group, negative control group and HIF-1α-siRNA group. Mouse bone marrow-derived macrophages (BMDMs) were isolated and cultured. The relative expression of CD206 and arginine (Arg) at mRNA level in mouse BMDMs was detected by RT-PCR. The proportions of F4/80 + CD16/32 + M1 and F4/80 + CD206 + M2 macrophages in spleen and thymus were detected by flow cytometry. Pathological changes in the ankle joint of mice were observed using HE staining. Immunohistochemistry was used to detect the expression of macrophages and the subsets in mouse synovial tissues. Results:(1) Compared with the control group, the CIA model group showed decreased expression of CD206 at mRNA level in BMDMs, but increased expression of Arg at mRNA level ( P<0.01). HIF-1α-siRNA increased the expression of CD206 at mRNA level ( P<0.05) and reduced the expression of Arg at mRNA level in BMDMs of mice with CIA ( P<0.01). (2) Compared with the control group, the mice in the CIA model group had increased proportions of F4/80 + CD16/32 + M1 macrophages in splenocytes and thymocytes ( P<0.05), but decreased proportions of F4/80 + CD206 + M2 macrophages in thymocytes ( P<0.05). HIF-1α-siRNA could down-regulate the proportions of F4/80 + CD16/32 + M1 macrophages in splenocytes and thymocytes ( P<0.05), and up-regulate the proportions of F4/80 + CD206 + M2 macrophages in thymocytes of CIA mice ( P<0.01). (3) CIA mice had synovial hyperplasia and macrophages infiltration, especially M1 macrophages, in the ankle joint. HIF-1α-siRNA could alleviate the synovial hyperplasia and macrophage infiltration. Conclusions:HIF-1α-siRNA could alleviate macrophage infiltration and synovial hyperplasia in CIA mice through reducing the proportions of M1 macrophages in thymocytes, BMDMs and synovial tissues and increasing the proportion of M2 macrophages, suggesting that HIF-1α-siRNA could treat CIA mice by regulating the differentiation of M1 and M2 macrophages.

Targeting macrophagic SHP2 for ameliorating osteoarthritis via TLR signaling

Osteoarthritis (OA), in which M1 macrophage polarization in the synovium exacerbates disease progression, is a major cause of cartilage degeneration and functional disabilities. Therapeutic strategies of OA designed to interfere with the polarization of macrophages have rarely been reported. Here, we report that SHP099, as an allosteric inhibitor of src-homology 2-containing protein tyrosine phosphatase 2 (SHP2), attenuated osteoarthritis progression by inhibiting M1 macrophage polarization. We demonstrated that M1 macrophage polarization was accompanied by the overexpression of SHP2 in the synovial tissues of OA patients and OA model mice. Compared to wild-type (WT) mice, myeloid lineage conditional Shp2 knockout (cKO) mice showed decreased M1 macrophage polarization and attenuated severity of synovitis, an elevated expression of cartilage phenotype protein collagen II (COL2), and a decreased expression of cartilage degradation markers collagen X (COL10) and matrix metalloproteinase 3 (MMP3) in OA cartilage. Further mechanistic analysis showed thatSHP099 inhibited lipopolysaccharide (LPS)-induced Toll-like receptor (TLR) signaling mediated by nuclear factor kappa B (NF-κB) and PI3K-AKT signaling. Moreover, intra-articular injection of SHP099 also significantly attenuated OA progression, including joint synovitis and cartilage damage. These results indicated that allosteric inhibition of SHP2 might be a promising therapeutic strategy for the treatment of OA.

miR-146b suppresses LPS-induced M1 macrophage polarization via inhibiting the FGL2-activated NF-κB/MAPK signaling pathway in inflammatory bowel disease

Abstract Objectives: M1 macrophage polarization and phenotype in Inflammatory Bowel Disease (IBD) are common biological responses. Method: Herein, IBD mice models were constructed and macrophages were derived. Results: It was discovered that microRNA-146b (miR-146b) was downregulated in IBD mice and Lipopolysaccharide (LPS)-induced macrophages. Moreover, the inhibitory role of overexpressed miR-146b in reducing the inflammation level and blocking M1 macrophage polarization was confirmed. Further investigation indicated that Fibrinogen Like 2 (FGL2) acted as the target gene of miR-146b, and FGL2 mediated activation of NLRP3, NF-κB-p65, and p38-MAPK. More importantly, it was validated that miR-146b could ameliorate inflammatory pheno-type and prevent M1 macrophage polarization via inhibiting FGL2 in vitro, and miR-146b overexpression alleviated the intestinal injury of IBD mice in vivo. Conclusions: Overall, it is potential to use miR-146b for the amelioration of IBD. HIGHLIGHTS miR-146b was downregulated in Inflammatory Bowel Disease (IBD) mice and LPS-induced macrophages. Fibrinogen Like 2 (FGL2) was identified as the target gene of miR-146b. miR-146b ameliorated the inflammation and blocked M1 macrophage polarization via inhibiting FGL2. miR-146b ameliorated the symptoms and pathological injury of IBD via inhibiting FGL2.

Sinomenine promotes paired immunoglobulin-like receptor B expression to restrain macrophage classic activation / 药学学报

In this study, in vitro experiments were conducted to investigate that sinomenine inhibits the macrophage classic activation by up-regulating the expression of paired immunoglobulin-like receptor B (PIR-B). A macrophage model with classic activation was established by lipopolysaccharide and interferon-gamma co-stimulation. Real-time fluorescence reverse transcription-polymerase chain reaction was executed for evaluating the PIR-B gene expression, and Western blot for PIR-B protein expression, in macrophages, respectively. The tumor necrosis factor α and interleukin 8 in cell culture supernatant were measured by enzyme-linked immunosorbent assay. The flow cytometry was utilized to detect M1 macrophages. The PIR-B expression in situ was observed by laser scanning confocal microscope. The results showed that sinomenine significantly increased the expression of PIR-B, markedly reduced the percentage of M1 macrophages, and decreased the levels of tumor necrosis factor α and interleukin 8 in the culture supernatant. The above results indicated that sinomenine can significantly inhibit the macrophage classic activation, and its mechanism may be related to the increase of PIR-B expression in macrophages. This pharmacological effect helps explain the pharmacodynamic mechanism of sinomenine in treating rheumatoid arthritis.

Phenotypic changes of spleen macrophages in advanced gastric cancer and their effects on proliferation, invasion and migration of gastric cancer cells / 西安交通大学学报(医学版)

Objective: To investigate the phenotypic changes of splenic macrophages in advanced gastric cancer and the effects of co-culture with M1 and M2 macrophages on gastric cancer cells in order to explore the role of the spleen in the development of gastric cancer. Methods: We collected the fresh surgically removed spleens from 15 patients who had undergone advanced proximal gastrectomy combined with splenectomy in our hospital from March 2015 to May 2017. Spleen macrophages were isolated from these spleen tissues and the macrophage phenotypes were detected by flow cytometry. Monocytes were isolated from fresh blood of healthy volunteers using a fully automated bead extraction system; the identified monocytes were given 10 ng/mL of GM-CSF and M-CSF to be induced into M1-type macrophages and M2-type macrophages, respectively. The phenotypes of macrophages were identified by flow cytometry using CD16 and CD163; the gastric cancer cells SGC-7901 and AGS were co-cultured with M1, M2 macrophages and monocytes using Transwell co-culture method; trypan blue staining was used to detect the proliferative, invasive and migratory abilities of the cells. Results: The proportion of type M2 macrophages in the spleen of patients with advanced gastric cancer was increased while the proportion of type M1 macrophages decreased. The mononuclear cells were induced into M1 and M2 macrophages by culture with GM-CSFand M-CSF, and the positive rate of monocytes was (95.46±4.21)% and (94.67±4.97)%, respectively; M2 macrophages and monocytes could promote the invasion and migration of gastric cancer cells, while M1 macrophages inhibited the invasion and migration of gastric cancer cells. Conclusion: This study identified the proportions of different macrophages in spleen tissues of patients with advanced gastric cancer, and confirmed that the different types of macrophages on gastric cancer cells have different effects. M2 macrophages promoted gastric cancer cells, while M1 macrophages showed the effect of inhibiting gastric cancer cells. Our research further revealed the role of the spleen in the progression of gastric cancer and provided experimental research basis for formulating a treatment plan for advanced gastric cancer.

Study of macrophage polarization on pulmonary fibrosis and signaling pathway / 中国中药杂志

Macrophages are a group of immune cells with pluripotency and plasticity that can differentiate into different phenotypes under different microenvironments in vitro and in vivo. In the development of pulmonary fibrosis, there are alveolar macrophages and interstitial macrophages, which are polarized to different cell phenotypes at different stages of development. And their polarized phenotypes include M1 macrophages and M2 macrophages. In the inflammation early stages of pulmonary fibrosis, the increase of classical activated macrophages are helpful to clear pathogenic microorganisms and promote the progress of inflammation. In the fibrosis stage, the alternatively activated macrophages increased, which inhibiting the inflammatory reaction or directly promoting tissue fibrosis, on the other hand, it also promoting the fibrosis degradation. To clarify the polarization and polarization mechanisms of macrophages in pulmonary fibrosis will be conducive to the treatment of pulmonary fibrosis. In IPF, the polarization mechanism of M1 and M2 is closely related to TGF-β1/Smad. TGF-β1/Smad pathway plays an important regulatory role in liver fibrosis, renal fibrosis, myocardial fibrosis, scars, tumors and other diseases. Blocking the signaling of TGF-β1 by Smad3 and Smad4 is beneficial to inhibit the polarization of AM, which in turn helps to inhibit the progression of IPF.

Selective M1 macrophage polarization in granuloma-positive and granuloma-negative Crohn's disease, in comparison to intestinal tuberculosis

BACKGROUND/AIMS: Classical M1 macrophage activation exhibits an inflammatory phenotype while alternative M2 macrophage activation exhibits an anti-inflammatory phenotype. We aimed to determine whether there are discriminant patterns of macrophage polarization in Crohn's disease (CD) and intestinal tuberculosis (iTB). METHODS: Colonic mucosal biopsies from 29 patients with iTB, 50 with CD, and 19 controls were examined. Dual colored immunohistochemistry was performed for iNOS/CD68 (an M1φ marker) and CD163/CD68 (an M2φ marker), and the ratio of M1φ to M2φ was assessed. To establish the innate nature of macrophage polarization, we analyzed the extent of mitochondrial depolarization, a key marker of inflammatory responses, in monocyte-derived macrophages obtained from CD and iTB patients, following interferon-γ treatment. RESULTS: M1φ polarization was more prominent in CD biopsies (P=0.002) than in iTB (P=0.2) and control biopsies. In granuloma-positive biopsies, including those in CD, M1φ predominance was significant (P=0.001). In iTB, the densities of M1φ did not differ between granuloma-positive and granuloma-negative biopsies (P=0.1). Interestingly, higher M1φ polarization in CD biopsies correlated with high inflammatory response exhibited by peripheral blood-derived monocytes from these patients. CONCLUSIONS: Proinflammatory M1φ polarization was more common in colonic mucosa of CD patients, especially in the presence of mucosal granulomas. Further characterization of the innate immune system could help in clarifying the pathology of iTB and CD.

Relationship between macrophage polarization and age-related macular degeneration / 中华实验眼科杂志

Age-related macular degeneration (AMD) is one of the leading causes to blindness worldwide in elderly population.Innate immune system elements, such as macrophages and cytokines, play an important role in AM D pathology and pathogenesis.In AMD,macrophages can be functionally polarized into M1 (classically activated) and M2 (alternatively activated), as well as regulatory cells, in response to systems biology approaches.Imbalances in the M1 and M2 populations together with activation of retinal microglia are observed and potentially contribute to tissue degeneration.In this review, the phenomenon of macrophage polarization in AMD study was summarized, and the relationship between macrophage polarization and dry AMD,wet AMD,AMD related risk factors were discussed.