Scavenger receptor A-mediated nanoparticles target M1 macrophages for acute liver injury

Acute liver injury(ALI)has an elevated fatality rate due to untimely and ineffective treatment.Although,schisandrin B(SchB)has been extensively used to treat diverse liver diseases,its therapeutic efficacy on ALI was limited due to its high hydrophobicity.Palmitic acid-modified serum albumin(PSA)is not only an effective carrier for hydrophobic drugs,but also has a superb targeting effect via scavenger receptor-A(SR-A)on the M1 macrophages,which are potential therapeutic targets for ALI.Compared with the common macrophage-targeted delivery systems,PSA enables site-specific drug delivery to reduce off-target toxicity.Herein,we prepared SchB-PSA nanoparticles and further assessed their therapeutic effect on ALI.In vitro,compared with human serum albumin encapsulated SchB nanoparticles(SchB-HSA NPs),the SchB-PSA NPs exhibited more potent cytotoxicity on lipopolysaccharide(LPS)stimulated Raw264.7(LAR)cells,and LAR cells took up PSA NPs 8.79 times more than HSA NPs.As expected,the PSA NPs also accumulated more in the liver.Moreover,SchB-PSA NPs dramatically reduced the activation of NF-κB signaling,and significantly relieved inflammatory response and hepatic necrosis.Notably,the high dose of SchB-PSA NPs improved the survival rate in 72 h of ALI mice to 75%.Hence,SchB-PSA NPs are promising to treat ALI.

RANKL-induced M1 macrophages are involved in bone formation

The activation of M1 macrophages can be achieved by stimulating them with lipopolysaccharide （LPS） and interferon-γ （IFN-γ）. However, M1 can be found under physiological conditions without any pathological stimuli. This study aimed to understand the involvement of RANKL-induced M1 macrophages in bone formation compared with pathologically induced macrophages. Fischer rats were used to investigate macrophage distribution in normal and injured femoral condyles in vivo. Bone marrow-derived macrophages （BMDMs） were activated with LPS＋IFN-γ and RANKL to achieve M1 activation in vitro. Gene expression related to inflammation, osteoclastogenesis, angiogenesis, and migration was determined by reverse transcription-quantitative polymerase chain reaction （RT-qPCR） and fluorescence-activated cell sorting （FACS）. Tissue macrophages showed distinct expression patterns at different bone regions. RANKL was found in close proximity to inducible nitric oxide synthase-positive （iNOS＋） cells in vivo, suggesting an association between RANKL expression and iNOS＋ cells, especially in trabecular bone. RANKL-induced macrophages showed a different cytokine secretion profile compared with pathologically induced macrophages. Both osteoclasts and M1 macrophages peaked on day 7 during bone healing. RANKL could trigger Ml-like macrophages with properties that were different from those of LPS＋IFN-γ-induced macrophages. These RANKL-activated M1 macrophages were actively involved in bone formation.

Th17/Treg balance and macrophage polarization ratio in lower extremity arteriosclerosis obliterans

Objective:To explore the balance of peripheral blood T helper 17 cells/regulatory T cell(Th17/Treg)ratio and the polarization ratio of M1 and M2 macrophages in lower extremity arteriosclerosis obliterans(ASO).Methods:A rat model of lower extremity ASO was established,and blood samples from patients with lower extremity ASO before and after surgery were obtained.ELISA was used to detect interleukin 6(IL-6),IL-10,and IL-17.Real-time RCR and Western blot analyses were used to detect Foxp3,IL-6,IL-10,and IL-17 expression.Moreover,flow cytometry was applied to detect the Th17/Treg ratio and M1/M2 ratio.Results:Compared with the control group,the iliac artery wall of ASO rats showed significant hyperplasia,and the concentrations of cholesterol and triglyceride were significantly increased(P<0.01),indicating the successful establishment of ASO.Moreover,the levels of IL-6 and IL-17 in ASO rats were pronouncedly increased(P<0.05),while the IL-10 level was significantly decreased(P<0.05).In addition to increased IL-6 and IL-17 levels,the mRNA and protein levels of Foxp3 and IL-10 in ASO rats were significantly decreased compared with the control group.The Th17/Treg and M1/M2 ratios in the ASO group were markedly increased(P<0.05).These alternations were also observed in ASO patients.After endovascular surgery(such as percutaneous transluminal angioplasty and arterial stenting),all these changes were significantly improved(P<0.05).Conclusions:The Th17/Treg and M1/M2 ratios were significantly increased in ASO,and surgery can effectively improve the balance of Th17/Treg,and reduce the ratio of M1/M2,and the expression of inflammatory factors.

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.

Growth differentiation factor 11 promotes macrophage polarization towards M2 to attenuate myocardial infarction via inhibiting Notch1 signaling pathway

Background:Myocardial infarctions(MI)is a major threat to human health especially in people exposed to cold environment.The polarization of macrophages towards different functional phenotypes(M1 macrophages and M2 macrophages)is closely related to MI repairment.The growth differentiation factor 11(GDF11)has been reported to play a momentous role in inflammatory associated diseases.In this study,we examined the regulatory role of GDF11 in macrophage polarization and elucidated the underlying mechanisms in MI.Methods:In vivo,the mice model of MI was induced by permanent ligation of the left anterior descending coronary artery(LAD),and mice were randomly divided into the sham group,MI group,and MI+GDF11 group.The protective effect of GDF11 on myocardial infarction and its effect on macrophage polarization were verified by echocardiography,triphenyl tetrazolium chloride staining and immunofluorescence staining of heart tissue.In vitro,based on the RAW264.7 cell line,the effect of GDF11 in promoting macrophage polarization toward the M2 type by inhibiting the Notch1 Signaling pathway was validated by qRT-PCR,Western blot,and flow cytometry.Results:We found that GDF11 was significantly downregulated in the cardiac tissue of MI mice.And GDF11 supplementation can improve the cardiac function.Moreover,GDF11 could reduce the proportion of M1 macrophages and increase the accumulation of M2 macrophages in the heart tissue of MI mice.Furthermore,the cardioprotective effect of GDF11 on MI mice was weakened after macrophage clearance.At the cellular level,application of GDF11 could inhibit the expression of M1 macrophage(classically activated macrophage)markers iNOS,interleukin(IL)-1β,and IL-6 in a dose-dependent manner.In contrast,GDF11 significantly increased the level of M2 macrophage markers including IL-10,CD206,arginase 1(Arg1),and vascular endothelial growth factor(VEGF).Interestingly,GDF11 could promote M1 macrophages polarizing to M2 macrophages.At the molecular level,GDF11 significantly down-regulated the Notch1 signaling pathway,the activation of which has been demonstrated to promote M1 polarization in macrophages.Conclusions:GDF11 promoted macrophage polarization towards M2 to attenuate myocardial infarction via inhibiting Notch1 signaling pathway.

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.

Morphofunctional Characteristics of Pulmonary Surfactant System and Its Effect on Immune Cells in Influenza A (H1N1) Pathogenesis

There is an annual increase of influenza-related SARI cases in winter months. Despite the high relevance of this problem, influenza pathogenesis and the role of surfactant system and its SP-A (surfactant protein A) enzyme in antiviral defense remain poorly understood. SP-A activates macrophage M1 polarization and triggers an antiviral response due to the activation of T-cells and dendritic cells. Therefore, surfactant system is an important element of infection protection and a promising therapeutic target.

Punicalagin ameliorates collagen-induced arthritis by downregulating M1 macrophage and pyroptosis via NF-κB signaling pathway

Rheumatoid arthritis(RA)is a chronic inflammatory disease that eventually leads to disability.Inflammatory cell infiltration,severe joint breaking and systemic bone loss are the main clinical symptoms.In this study,we established a collagen-induced arthritis(CIA)model and found a large number of M1 macrophages and pyroptosis,which are important sources of proinflammatory cytokines.Punicalagin(PUN)is an active substance extracted from pomegranate peel.We found that it inhibited joint inflammation,cartilage damage and systemic bone destruction in CIA mice.PUN effectively alleviated the high expression of inflammatory cytokines in synovial tissue in vivo.PUN treatment shifted macrophages from the M1 phenotype to the M2 phenotype after stimulation with lipopolysaccharide(LPS)and interferon(IFN)-γ.The expression of inducible nitric oxide synthase(i NOS)and other proinflammatory cytokines released by M1 macrophages was decreased in the PUN treatment group.However,simultaneously,the expression of markers of anti-inflammatory M2 macrophages,such as arginase(Arg)-1 and interleukin(IL)-10,was increased.In addition,PUN treatment attenuated pyroptosis by downregulating the expression of NLRP3 and caspase-1,thereby preventing inflammatory cell death resulting from the release of IL-1βand IL-18.Mechanistically,PUN inhibited the activation of receptor activators of the nuclear factor-κB(NF-κB)signaling pathway,which contributes to M1 polarization and pyroptosis of macrophages.We concluded that PUN ameliorated pathological inflammation by inhibiting M1 phenotype polarization and pyroptosis and has great potential as a therapeutic treatment for human RA.

Immunomodulatory hybrid bio-nanovesicle for self-promoted photodynamic therapy

Thylakoid(Tk)membranes are of unique superiority in photodynamic therapy(PDT)because they not only carry abundant chlorophylls containing photosensitizer porphyrin but also can produce O_(2).However,the current therapeutic performance of Tk is dramatically limited because of their poor tumor targeting and inefficient O_(2) production.Here,we report an immunomodulatory bio-nanovesicle of Tk membranes fused with M1 macrophage-derived extracellular vesicles(M1 EV)for efficient PDT of tumors.The hybrid nanovesicle Tk@M1 was prepared by squeezing the Tk membranes of spinach with M1 EV.The systemic study confirmed that Tk@M1 can not only actively accumulate in tumors but also effectively regulate the inactive immune microenvironment of tumors.Such activated"hot"tumors significantly enhance the PDT efficacy of Tk@M1 attributed to the increased O_(2) from catalase catalyzed decomposition of augmented H_(2)O_(2),providing a novel idea about constructing natural systems for effective tumor treatment.

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.

Co-administration of platelet-rich plasma and small intestinal submucosa is more beneficial than their individual use in promoting acute skin wound healing

Background:Acute skin wounds may compromise the skin barrier,posing a risk of infection.Small intestinal submucosa(SIS)is widely used to treat acute and chronic wounds.However,the efficacy of SIS to accelerate wound healing still needs to be improved to meet clinical demands.To tackle this problem,platelet-rich plasma(PRP)is used due to its potency to promote proliferation,migration and adhesion of target cells.In this study,we applied PRP and SIS to skin wounds to explore their effects on wound healing by evaluating re-epithelialization,collagen production,angiogenesis and the inflammatory response.Methods:A1×1-cm full-thickness skin defectwas established in mice.Sixty mice were divided into four treatment groups:PRP+SIS,PRP,SIS and control.On days 3,5,7,10 and 14 post-surgery,tissue specimens were harvested.Haematoxylin and eosin,Masson’s trichrome,immunohistochemical and immunofluorescence double staining were used to visualize epidermal thickness,collagen and vascular regeneration and inflammation.Results:Wound contraction in the PRP and PRP+SIS groups was significantly greater,compared with the other groups,on days 3 and 5 post-surgery.A histological analysis showed higher collagen expression in the PRP and PRP+SIS groups on day 7,whichwas associated with a thicker epidermal layer on day 14.In addition,immunohistochemical staining showed that CD31-positive blood vessels and vascular endothelial growth factor expression in the PRP+SIS and PRP groups were significantly higher,compared with the control group.Furthermore,immunofluorescence double staining showed that the number of M1 and M2 macrophages in the PRP+SIS and PRP groups was higher,compared with the control and SIS groups alone,on day 3.However,on day 7,the number of M1 macrophages dramatically decreased in the PRP+SIS and PRP groups.The ratio of M2 to M1 macrophages in the PRP+SIS and PRP groups was 3.97 and 2.93 times that of the control group and 4.56 and 3.37 times that of the SIS group,respectively.Conclusion:Co-administration of SIS and PRP has a better effect on promoting angiogenesis,reepithelialization and collagen regeneration in managing acute wound healing than either agent alone.