sDR5-Fc inhibits macrophage M1 polarization by blocking the glycolysis

BACKGROUND M1 polarization of macrophages is an important pathological process in myocardial ischemia reperfusion injury, which is the major obstacle for the treatment of acute myocardial infarction. Currently, the strategies and mechanisms of inhibiting M1 polarization are poorly explored. This study aims to investigate the role of soluble death receptor 5-Fc(s DR5-Fc) in regulating M1 polarization of macrophages under extreme conditions and explore the mechanisms from the aspect of glycolysis.METHODS Extreme conditions were induced in RAW264.7 cells. Real-time quantitative polymerase chain reaction and western blot were used to detect the expression of m RNA and proteins, respectively. Cell counting kit-8 was used to investigate the proliferation activity of cells. Expression levels of inflammatory cytokines were determined by enzyme-linked immunosorbent assay.RESULTS We found that s DR5-Fc rescues the proliferation of macrophages under extreme conditions, including nutrition deficiency, excessive peroxide, and ultraviolet irradiation. In addition, administration of s DR5-Fc inhibits the M1 polarization of macrophages induced by lipopolysaccharide(LPS) and interferon-gamma(IFN-γ), as the expression of M1 polarization markers CD86, CXC motif chemokine ligand 10, matrix metalloproteinase 9, and tumor necrosis factor-α, as well as the secretion of inflammatory factors interleukin(IL)-1β and IL-6, were significantly decreased. By further investigation of the mechanisms, the results showed that s DR5-Fc can recover the LPS and IFN-γ induced p H reduction, lactic acid elevation, and increased expression of hexokinase 2 and glucose transporter 1, which were markers of glycolysis in macrophages.CONCLUSIONS s DR5-Fc inhibits the M1 polarization of macrophages by blocking the glycolysis, which provides a new direction for the development of strategies in the treatment of myocardial ischemia reperfusion injury.

Poly(ADP-ribose)polymerase family member 14 promotes functional recovery after spinal cord injury through regulating microglia M1/M2 polarization via STAT1/6 pathway

Poly(ADP-ribose)polymerase family member 14(PARP14),which is an intracellular mono(ADP-ribosyl)transferase,has been reported to promote post-stroke functional recovery,but its role in spinal cord injury(SCI)remains unclear.To investigate this,a T10 spinal cord contusion model was established in C57BL/6 mice,and immediately after the injury PARP14 shRNA-carrying lentivirus was injected 1 mm from the injury site to silence PARP14 expression.We found that PARP14 was up-regulated in the injured spinal cord and that lentivirus-mediated downregulation of PARP14 aggravated functional impairment after injury,accompanied by obvious neuronal apoptosis,severe neuroinflammation,and slight bone loss.Furthermore,PARP14 levels were elevated in microglia after SCI,PARP14 knockdown activated microglia in the spinal cord and promoted a shift from M2-polarized microglia(anti-inflammatory phenotype)to M1-polarized microglia(pro-inflammatory phenotype)that may have been mediated by the signal transducers and activators of transcription(STAT)1/6 pathway.Next,microglia M1 and M2 polarization were induced in vitro using lipopolysaccharide/interferon-γand interleukin-4,respectively.The results showed that PARP14 knockdown promoted microglia M1 polarization,accompanied by activation of the STAT1 pathway.In addition,PARP14 overexpression made microglia more prone to M2 polarization and further activated the STAT6 pathway.In conclusion,these findings suggest that PARP14 may improve functional recovery after SCI by regulating the phenotypic transformation of microglia via the STAT1/6 pathway.

MST4 kinase regulates immune thrombocytopenia by phosphorylating STAT1-mediated M1 polarization of macrophages

Primary immune thrombocytopenia(ITP)is an autoimmune hemorrhagic disorder in which macrophages play a critical role.Mammalian sterile-20-like kinase 4(MST4),a member of the germinal-center kinase STE20 family,has been demonstrated to be a regulator of inflammation.Whether MST4 participates in the macrophage-dependent inflammation of ITP remains elusive.The expression and function of MST4 in macrophages of ITP patients and THP-1 cells,and of a macrophage-specific Mst4−/−(Mst4ΔM/ΔM)ITP mouse model were determined.Macrophage phagocytic assays,RNA sequencing(RNA-seq)analysis,immunofluorescence analysis,coimmunoprecipitation(co-IP),mass spectrometry(MS),bioinformatics analysis,and phosphoproteomics analysis were performed to reveal the underlying mechanisms.The expression levels of the MST4 gene were elevated in the expanded M1-like macrophages of ITP patients,and this elevated expression of MST4 was restored to basal levels in patients with remission after high-dose dexamethasone treatment.The expression of the MST4 gene was significantly elevated in THP-1-derived M1 macrophages.Silencing of MST4 decreased the expression of M1 macrophage markers and cytokines,and impaired phagocytosis,which could be increased by overexpression of MST4.In a passive ITP mouse model,macrophage-specific depletion of Mst4 reduced the numbers of M1 macrophages in the spleen and peritoneal lavage fluid,attenuated the expression of M1 cytokines,and promoted the predominance of FcγRIIb in splenic macrophages,which resulted in amelioration of thrombocytopenia.Downregulation of MST4 directly inhibited STAT1 phosphorylation,which is essential for M1 polarization of macrophages.Our study elucidates a critical role for MST4 kinase in the pathology of ITP and identifies MST4 kinase as a potential therapeutic target for refractory ITP.

Osteopontin Promotes Macrophage M1 Polarization by Activation of the JAK1/STAT1/HMGB1 Signaling Pathway in Nonalcoholic Fatty Liver Disease

Background and Aims:Osteopontin(OPN)is reported to be associated with the pathogenesis of nonalcoholic fatty liver disease(NAFLD).However,the function of OPN in NAFLD is still inconclusive.Therefore,our aim in this study was to evaluate the role of OPN in NAFLD and clarify the involved mechanisms.Methods:We analyzed the expression change of OPN in NAFLD by bioinformatic analysis,qRT-PCR,western blotting and immunofluorescence staining.To clarify the role of OPN in NAFLD,the effect of OPN from HepG2 cells on macrophage polarization and the involved mechanisms were examined by FACS and western blotting.Results:OPN was significantly upregulated in NAFLD patients compared with normal volunteers by microarray data,and the high expression of OPN was related with disease stage and progression.OPN level was also significantly increased in liver tissue samples of NAFLD from human and mouse,and in HepG2 cells treated with oleic acid(OA).Furthermore,the supernatants of OPN-treated HepG2 cells promoted the macrophage M1 polarization.Mechanistically,OPN activated the janus kinase 1(JAK1)/signal transducers and activators of transcription 1(STAT1)signaling pathway in HepG2 cells,and consequently HepG2 cells secreted more high-mobility group box 1(HMGB1),thereby promoting macrophage M1 polarization.Conclusions:OPN promoted macrophage M1 polarization by increasing JAK1/STAT1-induced HMGB1 secretion in hepatocytes.

Mechanism of Qishen Decoction inhibition of macrophage M1 type polarization by targeting TGR5-mediated NLRP3 inflammasome

Objective:To observe the effect of Qishen decoction on TGR5-mediated activation of NLRP3 inflammasome,so as to clarify the molecular mechanism of its inhibition of macrophage M1-type polarisation to ameliorate non-alcoholic steatohepatitis;Methods:Mouse macrophage cell line RAW264.7 was randomly divided into a control group,model group,Qishen decoction group,TGR5 agonist group and Qishen decoction+TGR5 agonist group.Except for the control group,the remaining groups were constructed the macrophage NLRP3 activation model by palmitic acid induction,and the corresponding drugs were given to intervene.ELISA was used to detect the levels of TNF-α,IL-6,IL-1βand CXCL2 in macrophage supernatants,flow cytometry was used to detect the expression levels of macrophage polarisation marker molecules CD86 and iNOS,and Western blot was used to detect the expression of the TGR5/STAT1/STAT6 signaling pathway and the expression of NLRP3 inflammasome-associated proteins,respectively.Results:Compared with the control group,the contents of macrophages TNF-α,IL-6,IL-1β,CXCL2 and the proportion of macrophages with positive expression of CD86 and iNOS were significantly increased in the model group,and the differences were all statistically significant(P<0.01).Compared with the model group,the contents of TNF-α,IL-6,IL-1β,CXCL2 and the proportion of macrophages with positive expression of CD86 and iNOS were significantly decreased in the Qishen decoction group,and the differences were all statistically significant(P<0.01).In addition,the expression of NLRP3 and Pro-IL-1βproteins in the macrophage lysate and the expression of Caspase-1 p10,Caspase-1 p20 and IL-1βp17 proteins in the cell supernatant of the model group were significantly increased when compared with the control group,and the differences were all statistically significant(P<0.01).Compared with the model group,the expression of NLRP3 and Pro-IL-1βproteins in macrophage lysate and the expression of Caspase-1 p10,Caspase-1 p20 and IL-1βp17 proteins in cell supernatant of the Qishen decoction were significantly reduced,and the differences were all statistically significant(P<0.01);Conclusion:Qishen decoction can inhibit the activation of NLRP3 inflammasome in macrophages by inhibiting the TGR5/STAT1/STAT6 signaling pathway,thereby inhibiting macrophage M1 polarization and improving inflammatory response.

Tetrahedral DNA nanostructures synergize with MnO_(2) to enhance antitumor immunity via promoting STING activation and M1 polarization

Stimulator of interferon genes(STING) is a cytosolic DNA sensor which is regarded as a potential target for antitumor immunotherapy. However, clinical trials of STING agonists display limited anti-tumor effects and dose-dependent side-effects like inflammatory damage and cell toxicity. Here,we showed that tetrahedral DNA nanostructures(TDNs) actively enter macrophages to promote STING activation and M1 polarization in a size-dependent manner, and synergized with Mn^(2+) to enhance the expressions of IFN-β and iNOS, as well as the co-stimulatory molecules for antigen presentation. Moreover, to reduce the cytotoxicity of Mn^(2+),we constructed a TDN-MnO_(2) complex and found that it displayed a much higher efficacy than TDN plus Mn^(2+) to initiate macrophage activation and anti-tumor response both in vitro and in vivo. Together, our studies explored a novel immune activation effect of TDN in cancer therapy and its synergistic therapeutic outcomes with MnO_(2).These findings provide new therapeutic opportunities for cancer therapy.

M1-type microglia can induce astrocytes to deposit chondroitin sulfate proteoglycan after spinal cord injury

After spinal cord injury(SCI),astrocytes gradually migrate to and surround the lesion,depositing chondroitin sulfate proteoglycan-rich extracellular matrix and forming astrocytic scar,which limits the spread of inflammation but hinders axon regeneration.Meanwhile,microglia gradually accumulate at the lesion border to form microglial scar and can polarize to generate a pro-inflammatory M1 phenotype or an anti-inflammatory M2 phenotype.However,the effect of microglia polarization on astrocytes is unclear.Here,we found that both microglia(CX3 CR1^(+))and astrocytes(GFAP^(+))gathered at the lesion border at 14 days post-injury(dpi).The microglia accumulated along the inner border of and in direct contact with the astrocytes.M1-type microglia(i NOS^(+)CX3 CR1^(+))were primarily observed at 3 and 7 dpi,while M2-type microglia(Arg1^(+)CX3 CR1^(+))were present at larger numbers at 7 and 14 dpi.Transforming growth factor-β1(TGFβ1)was highly expressed in M1 microglia in vitro,consistent with strong expression of TGFβ1 by microglia in vivo at 3 and 7 dpi,when they primarily exhibited an M1 phenotype.Furthermore,conditioned media from M1-type microglia induced astrocytes to secrete chondroitin sulfate proteoglycan in vitro.This effect was eliminated by knocking down sex-determining region Y-box 9(SOX9)in astrocytes and could not be reversed by treatment with TGFβ1.Taken together,our results suggest that microglia undergo M1 polarization and express high levels of TGFβ1 at 3 and 7 dpi,and that M1-type microglia induce astrocytes to deposit chondroitin sulfate proteoglycan via the TGFβ1/SOX9 pathway.The study was approved by the Institutional Animal Care and Use Committee of Anhui Medical University,China(approval No.LLSC20160052)on March 1,2016.

Shikonin alleviates collagen-induced arthritis mice by inhibiting M1 macrophage polarization

OBJECTIVE: To investigate the effects of shikonin(SKN) on M1 and M2 polarization of macrophages both in vitro and in vivo. METHODS: Collagen-induced arthritis(CIA) in male DBA/1 mice were treated with a dose of 4 mg/kg/day of SKN for 23 d(n = 6/group). The histopathology of inflamed joints in CIA mice was evaluated to test the antiarthritic effect of SKN. M1/M2 polarization of macrophages induced by lipopolysaccharide(LPS) and interferon(IFN)-γ or interleukin(IL)-4 and IL-13, were used to assess the effect of SKN(0.05, 0.1, and 0.2 μM). The effect of SKN on the protein expression of nitric oxide synthase, arginase, CD68, and CD206 was evaluated using western blot analysis. RESULTS: The results of this study revealed that SKN delayed the arthritis feet symptom score, reduced the incidence rate of arthritis, and relieved the inflammation of joints in CIA mice. SKN inhibited M1 macrophage polarization but did not affect M2 macrophage polarization in the joints of CIA mice. Moreover, SKN inhibited M1 polarization induced by LPS and IFN-γ, but did not affect M2 polarization induced by IL-4 and IL-13. CONCLUSION: These findings suggest that SKN alleviated CIA through inhibiting M1 macrophage polarization and has great potential as a new drug for RA treatment.

Effects of Total Saponins from Dioscorea Nipponica Makino on Monosodium Urate-Induced M1-Polarized Macrophages through Arachidonic Acid Signaling Pathway:An in vitro Study

Objective To investigate and reveal the underlying mechanism of the effect of total saponins from Dioscoreae nipponica Makino(TSDN)on the arachidonic acid pathway in monosodium urate(MSU)crystal-induced M1-polarized macrophages.Methods M1 polarization of RAW264.7 cells were induced by 1µg/mL lipopolysaccharide(LPS).The methylthiazolyldiphenyl-tetrazolium bromide method was then used to screen the concentration of TSDN.MSU(500µg/mL)was used to induce the gouty arthritis model.Afterwards,10µg/L TSDN and 8µmol/L celecoxib,which was used as a positive control,were added to the above LPS and MSU-induced cells for 24 h.The mRNA and protein expressions of cyclooxygenase(COX)2,5-lipoxygenase(5-LOX),microsomal prostaglandin E synthase derived eicosanoids(mPGES)-1,leukotriene B(LTB)4,cytochrome P450(CYP)4A,and prostaglandin E_(2)(PGE_(2))were tested by real-time polymerase chain reaction and Western blotting,respectively.The enzyme-linked immunosorbent assay was used to test the contents of M1 markers,including inducible nitric oxid synthase(NOS)2,CD80,and CD86.Results TSDN inhibited the proliferation of M1 macrophages and decreased both the mRNA and protein expressions of COX2,5-LOX,CYP4A,LTB4,and PGE_(2)(P<0.01)while increased the mRNA and protein expression of mPGES-1(P<0.05 or P<0.01).TSDN could also significantly decrease the contents of NOS2,CD80,and CD86(P<0.01).Conclusion TSDN has an anti-inflammation effect on gouty arthritis in an in vitro model by regulating arachidonic acid signaling pathway.

Periplaneta americana extract promotes infectious diabetic ulcers wound healing by downregulation of LINC01133/SLAMF9

Wound healing in diabetic ulcers remains a significant clinical challenge,primarily due to bacterial infection and impaired angiogenesis.Periplaneta americana extract(PAE)has been widely used to treat diabetic wounds,yet its underlying mechanisms are not fully understood.This study aimed to elucidate these mechanisms by analyzing long non-coding RNA(lncRNA)expressions in the wound tissues from diabetic anal fistula patients treated with or without PAE,using high-throughput sequencing.Peripheral blood monocytes from patients were differentiated into M0 macrophages with human macrophage colony-stimulating factor(hMCSF)and subsequently polarized into M1 macrophages with lipopolysaccharide.The results indicated that LINC01133 and SLAMF9 were downregulated in wound tissues of patients treated with PAE.Furthermore,PAE suppressed M1 macrophage polarization and enhanced human umbilical vein endothelial cell(HUVEC)proliferation,migration,and angiogenesis.These effects were diminished when LINC01133 or SLAMF9 were overexpressed.Mechanistically,LINC01133 was shown to upregulate SLAMF9 through interaction with ELAVL1.Overexpression of SLAMF9 reversed the effects of LINC01133 silencing on macrophage polarization and HUVEC functions.In conclusion,PAE facilitates the healing of infected diabetic ulcers by downregulating the LINC01133/SLAMF9 pathway.

An HBV-encoded miRNA activates innate immunity to restrict HBV replication

We previously identified that hepatitis B virus(HBV)encodes a microRNA(HBV-miR-3)that restrains HBV replication by targeting the HBV transcript.However,whether HBV-miR-3 affects host innate immunity to modulate HBV replication remains unclear.Here,we examined the vital functions of HBV-miR-3 in the innate immune response after HBV infection.We found that HBV-miR-3 expression gradually increased in a dose-and time-dependent manner in HBV-infected HepG2-NTCP cells.HBV-miR-3 activated the JAK/STAT signaling pathway by downregulating SOCS5 in hepatocytes,thereby enhancing the IFN-induced anti-HBV effect.In addition,HBVmiR-3 in exosomes facilitated the Ml polarization of macrophages.Furthermore,exosomes containing HBV-miR-3 enhanced the secretion of IL-6 via inhibiting the SOCS5-mediated ubiquitination of EGFR.In short,these results demonstrate that HBV-miR-3 activates the innate immune response to restrain HBV replication by multiple pathways,which may suppress HBV-induced acute liver cell injury and affect the progression of persistent HBV infection.

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(c KO)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 metalloproteinase3(MMP3)in OA cartilage.Further mechanistic analysis showed that SHP099 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.