Atherosis-associated lnc_000048 activates PKR to enhance STAT1-mediated polarization of THP-1 macrophages to M1 phenotype

Our previous study has demonstrated that lnc_000048 is upregulated in large-artery atherosclerotic stroke and promotes atherosclerosis in ApoE^(-/-)mice.However,little is known about the role of lnc_000048 in classically activated macrophage(M1)polarization.In this study,we established THP-1-derived testing state macrophages(M0),M1 macrophages,and alternately activated macrophages(M2).Real-time fluorescence quantitative PCR was used to verify the expression of marker genes and the expression of lnc_000048 in macrophages.Flow cytometry was used to detect phenotypic proteins(CD11b,CD38,CD80).We generated cell lines with lentivirus-mediated upregulation or downregulation of lnc_000048.Flow cytometry,western blot,and real-time fluorescence quantitative PCR results showed that down-regulation of lnc_000048 reduced M1 macrophage polarization and the inflammation response,while over-expression of lnc_000048 led to the opposite effect.Western blot results indicated that lnc_000048 enhanced the activation of the STAT1 pathway and mediated the M1 macrophage polarization.Moreover,catRAPID prediction,RNA-pull down,and mass spectrometry were used to identify and screen the protein kinase RNA-activated(PKR),then catRAPID and RPIseq were used to predict the binding ability of lnc_000048 to PKR.Immunofluorescence(IF)-RNA fluorescence in situ hybridization(FISH)double labeling was performed to verify the subcellular colocalization of lnc_000048 and PKR in the cytoplasm of M1 macrophage.We speculate that lnc_000048 may form stem-loop structure-specific binding and activate PKR by inducing its phosphorylation,leading to activation of STAT1 phosphorylation and thereby enhancing STAT1 pathway-mediated polarization of THP-1 macrophages to M1 and inflammatory factor expression.Taken together,these results reveal that the lnc_000048/PKR/STAT1 axis plays a crucial role in the polarization of M1 macrophages and may be a novel therapeutic target for atherosclerosis alleviation in stroke.

Streptococcus mutans activates the AIM2, NLRP3 and NLRC4 inflammasomes in human THP-1 macrophages

Streptococcus mutans(S. mutans), a major aetiologic agent of dental caries, is involved in systemic diseases, such as bacterial endocarditis, if it enters the bloodstream through temporary bacteraemia. Interleukin(IL)-1β, a proinflammatory cytokine, is related to the host defences against pathogens, and its synthesis, maturation, and secretion are tightly regulated by the activation of the inflammasome, an inflammatory signalling complex. This study examined the signalling mechanism of IL-1β secretion and the inflammasome pathway induced by S. mutans to explain the molecular mechanism through which systemic infection by oral streptococci can occur. After infection of THP-1 cells with S. mutans, the expression of inflammasome components was detected using various methods. S. mutans induced IL-1β secretion via caspase-1 activation, and S. mutans-induced IL-1β secretion required absent in melanoma(AIM2), NLR family pyrin domain-containing 3(NLRP3) and NLR family CARD domain-containing 4(NLRC4)inflammasome activation. In particular, the S. mutans-induced NLRP3 inflammasome was mediated by adenosine triphosphate(ATP) release, potassium depletion and lysosomal damage. Our study provides novel insight into the innate immune response against S. mutans infection.

Neutrophil peptide 1 accelerates the clearance of degenerative axons during Wallerian degeneration by activating macrophages after peripheral nerve crush injury

Macrophages play an important role in peripheral nerve regeneration,but the specific mechanism of regeneration is still unclear.Our preliminary findings indicated that neutrophil peptide 1 is an innate immune peptide closely involved in peripheral nerve regeneration.However,the mechanism by which neutrophil peptide 1 enhances nerve regeneration remains unclear.This study was designed to investigate the relationship between neutrophil peptide 1 and macrophages in vivo and in vitro in peripheral nerve crush injury.The functions of RAW 264.7 cells we re elucidated by Cell Counting Kit-8 assay,flow cytometry,migration assays,phagocytosis assays,immunohistochemistry and enzyme-linked immunosorbent assay.Axonal debris phagocytosis was observed using the CUBIC(Clear,Unobstructed Brain/Body Imaging Cocktails and Computational analysis)optical clearing technique during Wallerian degeneration.Macrophage inflammatory factor expression in different polarization states was detected using a protein chip.The results showed that neutrophil peptide 1 promoted the prolife ration,migration and phagocytosis of macrophages,and CD206 expression on the surfa ce of macrophages,indicating M2 polarization.The axonal debris clearance rate during Wallerian degeneration was enhanced after neutrophil peptide 1 intervention.Neutrophil peptide 1 also downregulated inflammatory factors interleukin-1α,-6,-12,and tumor necrosis factor-αin invo and in vitro.Thus,the results suggest that neutrophil peptide 1 activates macrophages and accelerates Wallerian degeneration,which may be one mechanism by which neutrophil peptide 1 enhances peripheral nerve regeneration.

Small extracellular vesicles from hypoxia-preconditioned bone marrow mesenchymal stem cells attenuate spinal cord injury via miR-146a-5p-mediated regulation of macrophage polarization

Spinal cord injury is a disabling condition with limited treatment options.Multiple studies have provided evidence suggesting that small extracellular vesicles(SEVs)secreted by bone marrow mesenchymal stem cells(MSCs)help mediate the beneficial effects conferred by MSC transplantation following spinal cord injury.Strikingly,hypoxia-preconditioned bone marrow mesenchymal stem cell-derived SEVs(HSEVs)exhibit increased therapeutic potency.We thus explored the role of HSEVs in macrophage immune regulation after spinal cord injury in rats and their significance in spinal cord repair.SEVs or HSEVs were isolated from bone marrow MSC supernatants by density gradient ultracentrifugation.HSEV administration to rats via tail vein injection after spinal cord injury reduced the lesion area and attenuated spinal cord inflammation.HSEVs regulate macrophage polarization towards the M2 phenotype in vivo and in vitro.Micro RNA sequencing and bioinformatics analyses of SEVs and HSEVs revealed that mi R-146a-5p is a potent mediator of macrophage polarization that targets interleukin-1 receptor-associated kinase 1.Reducing mi R-146a-5p expression in HSEVs partially attenuated macrophage polarization.Our data suggest that HSEVs attenuate spinal cord inflammation and injury in rats by transporting mi R-146a-5p,which alters macrophage polarization.This study provides new insights into the application of HSEVs as a therapeutic tool for spinal cord injury.

Spi1 regulates the microglial/macrophage inflammatory response via the PI3K/AKT/mTOR signaling pathway after intracerebral hemorrhage

Preclinical and clinical studies have shown that microglia and macrophages participate in a multiphasic brain damage repair process following intracerebral hemorrhage.The E26 transformation-specific sequence-related transcription factor Spi1 regulates microglial/macrophage commitment and maturation.However,the effect of Spi1 on intracerebral hemorrhage remains unclear.In this study,we found that Spi1 may regulate recovery from the neuroinflammation and neurofunctional damage caused by intracerebral hemorrhage by modulating the microglial/macrophage transcriptome.We showed that high Spi1expression in microglia/macrophages after intracerebral hemorrhage is associated with the activation of many pathways that promote phagocytosis,glycolysis,and autophagy,as well as debris clearance and sustained remyelination.Notably,microglia with higher levels of Soil expression were chara cterized by activation of pathways associated with a variety of hemorrhage-related cellular processes,such as complement activation,angiogenesis,and coagulation.In conclusion,our results suggest that Spi1 plays a vital role in the microglial/macrophage inflammatory response following intracerebral hemorrhage.This new insight into the regulation of Spi1 and its target genes may advance our understanding of neuroinflammation in intracerebral hemorrhage and provide therapeutic targets for patients with intracerebral hemorrhage.

Knockout of C6orf120 in Rats Alleviates Concanavalin A-induced Autoimmune Hepatitis by Regulating Macrophage Polarization

Objective The effect of the functionally unknown gene C6orf120 on autoimmune hepatitis was investigated on C6orf120 knockout rats(C6orf120^(-/-))and THP-1 cells.Method Six–eight-week-old C6orf120^(-/-)and wild-type(WT)SD rats were injected with Con A(16 mg/kg),and euthanized after 24 h.The sera,livers,and spleens were collected.THP-1 cells and the recombinant protein(rC6ORF120)were used to explore the mechanism in vitro.The frequency of M1 and M2 macrophages was analyzed using flow cytometry.Western blotting and PCR were used to detect macrophage polarization-associated factors.Results C6orf120 knockout attenuated Con A-induced autoimmune hepatitis.Flow cytometry indicated that the proportion of CD68^(+)CD86^(+)M1 macrophages from the liver and spleen in the C6orf120^(-/-)rats decreased.C6orf120 knockout induced downregulation of CD86 protein and the mRNA levels of related inflammatory factors TNF-α,IL-1β,and IL-6 in the liver.C6orf120 knockout did not affect the polarization of THP-1 cells.However,rC6ORF120 promoted the THP-1 cells toward CD68^(+)CD80^(+)M1 macrophages and inhibited the CD68^(+)CD206^(+)M2 phenotype.Conclusion C6orf120 knockout alleviates Con A-induced autoimmune hepatitis by inhibiting macrophage polarization toward M1 macrophages and reducing the expression of related inflammatory factors in C6orf120^(-/-)rats.

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.

ATAT1 deficiency enhances microglia/macrophage-mediated erythrophagocytosis and hematoma absorption following intracerebral hemorrhage

MIcroglia/macrophage-mediated erythrophagocytosis plays a crucial role in hematoma clearance after intracerebral hemorrhage.Dynamic cytoskeletal changes accompany phagocytosis.However,whether and how these changes are associated with microglia/macrophage-mediated erythrophagocytosis remain unclear.In this study,we investigated the function of acetylatedα-tubulin,a stabilized microtubule form,in microglia/macrophage erythrophagocytosis after intracerebral hemorrhage both in vitro and in vivo.We first assessed the function of acetylatedα-tubulin in erythrophagocytosis using primary DiO GFP-labeled red blood cells co-cultured with the BV2 microglia or RAW264.7 macrophage cell lines.Acetylatedα-tubulin expression was significantly decreased in BV2 and RAW264.7 cells during erythrophagocytosis.Moreover,silencingα-tubulin acetyltransferase 1(ATAT1),a newly discoveredα-tubulin acetyltransferase,decreased Ac-α-tub levels and enhanced the erythrophagocytosis by BV2 and RAW264.7 cells.Consistent with these findings,in ATAT1-/-mice,we observed increased ionized calcium binding adapter molecule 1(Iba1)and Perls-positive microglia/macrophage phagocytes of red blood cells in peri-hematoma and reduced hematoma volume in mice with intracerebral hemorrhage.Additionally,knocking out ATAT1 alleviated neuronal apoptosis and pro-inflammatory cytokines and increased anti-inflammatory cytokines around the hematoma,ultimately improving neurological recovery of mice after intracerebral hemorrhage.These findings suggest that ATAT1 deficiency accelerates erythrophagocytosis by microglia/macrophages and hematoma absorption after intracerebral hemorrhage.These results provide novel insights into the mechanisms of hematoma clearance and suggest ATAT1 as a potential target for the treatment of intracerebral hemorrhage.

FHL2通过NF-κB信号通路调节THP-1巨噬细胞泡沫化

目的 明确4个半LIM结构域蛋白(FHL2)是否能够通过调节核因子κB(NF-κB)信号通路影响巨噬细胞泡沫化。方法 构建FHL2过表达质粒及合成FHL2小干扰RNA(si-FHL2),分别转染至人单核/巨噬细胞系THP-1中,Western blot检测FHL2表达;使用氧化低密度脂蛋白(ox-LDL)刺激细胞,ELISA检测细胞IL-6、IL-1β、TNF-α等细胞因子的表达;油红O染色检测细胞泡沫化程度;Western blot检测NF-κB信号通路相关蛋白表达。结果 转染过表达FHL2质粒的细胞中FHL2表达量升高(P<0.01),而转染si-FHL2的细胞表达量降低(P<0.05);敲低FHL2能够下调炎性细胞因子的分泌(P<0.01);FHL2下调能够缓解THP-1巨噬细胞泡沫化;同时,FHL2下调抑制NF-κB信号通路的活化(P<0.05),而在过表达FHL2组中结果呈相反趋势。结论 下调FHL2的表达可通过抑制NF-κB信号通路活化,降低炎性细胞因子的分泌,缓解巨噬细胞的泡沫化。

茶黄素对ox-LDL诱导的THP-1巨噬细胞泡沫化和氧化应激的影响

[目的]探索茶黄素对氧化型低密度脂蛋白(ox-LDL)诱导的THP-1巨噬细胞泡沫化和氧化应激的影响及机制。[方法]使用50μmol/L茶黄素、10μmol/L核因子E2相关因子2(NRF2)抑制剂ML385预处理THP-1来源的巨噬细胞,随后加入100 mg/L ox-LDL刺激细胞24 h建立泡沫细胞模型。通过CCK-8法和LDH释放量检测茶黄素对THP-1巨噬细胞活力的影响。通过RT-qPCR和Western blot检测炎症因子白细胞介素6(IL-6)、白细胞介素1β(IL-1β)、肿瘤坏死因子α(TNF-α)的表达;ELISA法检测炎症因子的释放。采用油红O染色检测细胞内脂质积累,DiL标记氧化型低密度脂蛋白(DiL-ox-LDL)染色检测脂质摄取,DCFH-DA探针检测活性氧(ROS)水平。通过Western blot和RT-qPCR检测脂质摄取、胆固醇外排及氧化应激相关蛋白的表达。[结果]经100 mg/L的ox-LDL处理,THP-1巨噬细胞活力明显降低,脂质摄取、积累明显增加,脂质摄取相关蛋白表达增加,胆固醇外排相关蛋白表达明显减少,炎症与ROS水平明显增加,髓过氧化物酶(MPO)和NADPH氧化酶2(NOX2)表达增加(P<0.05);加入茶黄素后,细胞活力升高,细胞内脂质积累明显减少,脂质摄取相关蛋白的表达明显减少,胆固醇外排相关蛋白表达明显增多,炎症因子IL-6、IL-1β、TNF-α的表达与释放明显降低,ROS水平降低,MPO与NOX2表达减少(P<0.05)。茶黄素预处理改变了NRF2信号通路中NRF2、血红素加氧酶1(HO-1)、Kelch样ECH关联蛋白1(KEAP1)的表达,增加了NRF2核易位,减缓了细胞内氧化应激。ML385预处理细胞后,NRF2、HO-1、KEAP1和CD36蛋白表达水平明显降低。[结论]茶黄素可以显著抑制THP-1巨噬细胞泡沫化,抑制ox-LDL诱导的THP-1巨噬细胞炎症并通过NRF2/HO-1信号通路减缓了氧化应激。

基于CRISPR/Cas9技术构建IDO1基因敲除的THP-1细胞株及其表型研究

目的 采用CRISPR/Cas9技术构建吲哚胺-2,3-双加氧酶1(IDO1)基因敲除的THP-1细胞株,为研究IDO1在巨噬细胞中的作用提供细胞模型。方法 设计靶向IDO1基因的3条向导RNA(guide RNA,gRNA),分别构建IDO1-gRNA重组质粒,酶切及测序鉴定后,包装成Lenti-IDO1-gRNA慢病毒。利用Cas9慢病毒感染THP-1细胞获得稳定表达Cas9蛋白的细胞株,再经Lenti-IDO1-gRNA慢病毒感染敲除IDO1基因,有限稀释法获得单克隆细胞株。T7E1酶切检测gRNA打靶效率,PCR产物测序和Western blot鉴定IDO1基因敲除效果。CCK8法检测IDO1基因敲除对THP-1细胞增殖活性的影响,流式细胞术检测对巨噬细胞标志物CD11b、CD68和CD14表达的影响,中性红法检测巨噬细胞吞噬功能。结果 成功构建了3种IDO1-gRNA重组质粒,3条gRNA均能有效编辑IDO1基因,以gRNA2编辑效率最高。经PCR产物测序和Western blot验证获得了3株THP-1 IDO1-KO单克隆细胞株,并发现IDO1基因敲除可抑制THP-1细胞增殖,下调THP-1巨噬细胞CD11b、CD68表达,上调CD14表达,增强THP-1巨噬细胞吞噬功能。结论 成功构建IDO1基因敲除的THP-1细胞株;IDO1对THP-1细胞增殖活性、分化调节以及THP-1巨噬细胞吞噬功能调节有重要作用,为后续进一步探讨IDO1基因在巨噬细胞中的功能及机制研究奠定基础。

RNA结合蛋白RBPMS调控急性髓系白血病细胞系THP-1增殖与迁移

目的研究具有多重剪接功能的RNA结合蛋白(RBPMS)对携带MLL-AF9融合基因的急性髓系白血病细胞系THP-1功能的影响。方法使用GEO数据库分析造血系统中RBPMS的表达情况;通过慢病毒感染THP-1细胞,RT-qPCR和Western blot检测RBPMS过表达效率;通过高通量测序检测RBPMS过表达后对THP-1细胞转录组的影响。分别用CCK-8法和流式细胞仪检测RBPMS过表达对白血病细胞增殖以及迁移能力的影响。结果RBPMS在携带MLL-AF9融合基因的急性髓系白血病干细胞中异常低表达。RBPMS过表达后THP-1细胞的增殖和迁移能力显著降低(P<0.0001,P<0.05)。结论RBPMS可以抑制携带MLL-AF9融合基因的急性髓系白血病细胞系的细胞增殖与迁移。

钙结合蛋白S100A4对BCG感染THP-1细胞自噬的调控作用

本研究旨在探究牛结核分枝杆菌减毒株卡介苗(Bacillus Calmette-Guérin,BCG)感染人单核巨噬细胞THP-1后,钙结合蛋白S100A4对细胞自噬的调控作用。以感染复数为10∶1的BCG感染THP-1细胞不同时间,用Western blot检测S100A4和LC3Ⅱ的表达,以确定最佳感染时间,并采用透射电镜观察自噬体数量变化。在BCG单独感染或与S100A4小干扰RNA共处理THP-1细胞12 h后,采用qRT-PCR检测S100A4及自噬相关因子--微管相关蛋白轻链3II (microtubule-associated protein light chain 3Ⅱ, LC3Ⅱ)、自噬相关蛋白7(autophagy-related gene 7, Atg7)、Beclin-1在mRNA水平上的表达,采用Western blot检测S100A4、LC3Ⅱ、Atg7、Beclin-1在蛋白水平的表达。利用mRFP-GFP-LC3检测自噬流,激光共聚焦显微镜观察细胞中mRFP-LC3和mRFP-GFP-LC3点状聚集。结果显示:在BCG感染THP-1细胞不同时间后,S100A4和LC3Ⅱ在蛋白表达水平随感染时间的延长先上升后下降,在12 h时表达最高(P<0.001),且自噬体数量明显增多。在mRNA水平上,与siNC组相比,siNC+BCG感染组S100A4、LC3Ⅱ、Atg7、Beclin-1的mRNA表达水平显著上调(P<0.05),当BCG和siS100A4共处理后,S100A4、LC3Ⅱ、Atg7、Beclin-1在mRNA水平的表达显著(P<0.05)或极显著(P<0.01,P<0.001)下调;在蛋白水平上,与未感染组相比,S100A4、LC3Ⅱ、Atg7、Beclin-1的蛋白表达量显著增多(P<0.05),BCG和siS100A4共处理后,S100A4、LC3Ⅱ、Atg7、Beclin-1的蛋白表达量均极显著减少(P<0.001);与未感染组相比,BCG组自噬体的数量极显著增多(P<0.01),siS100A4+BCG组与siNC+BCG组相比,自噬体的数量显著减少(P<0.05)。S100A4对BCG感染巨噬细胞诱导的自噬具有调控作用,S100A4能够促进BCG诱导的THP-1细胞自噬。

Mechanism of annexin A1/N-formylpeptide receptor regulation of macrophage function to inhibit hepatic stellate cell activation through Wnt/β-catenin pathway

BACKGROUND Hepatic fibrosis is a common pathological process of chronic liver diseases with various causes,which can progress to cirrhosis.AIM To evaluate the effect and mechanism of action annexin(Anx)A1 in liver fibrosis and how this could be targeted therapeutically.METHODS CCl4(20%)and active N-terminal peptide of AnxA1(Ac2-26)and N-formylpeptide receptor antagonist N-Boc-Phe-Leu-Phe-Leu-Phe(Boc2)were injected intraperitoneally to induce liver fibrosis in eight wild-type mice/Anxa1 knockout mice,and to detect expression of inflammatory factors,collagen deposition,and the role of the Wnt/β-catenin pathway in hepatic fibrosis.RESULTS Compared with the control group,AnxA1,transforming growth factor(TGF)-β1,interleukin(IL)-1βand IL-6 expression in the liver of mice with hepatic fibrosis induced by CCl4 was significantly increased,which promoted collagen deposition and expression ofα-smooth muscle actin(α-SMA),collagen type I and connective tissue growth factor(CTGF),and increased progressively with time.CCl4 induced an increase in TGF-β1,IL-1βand IL-6 in liver tissue of AnxA1 knockout mice,and the degree of liver inflammation and fibrosis and expression ofα-SMA,collagen I and CTGF were significantly increased compared with in wild-type mice.After treatment with Ac2-26,expression of liver inflammatory factors,degree of collagen deposition and expression of a-SMA,collagen I and CTGF were decreased compared with before treatment.Boc2 inhibited the anti-inflammatory and antifibrotic effects of Ac2-26.AnxA1 downregulated expression of the Wnt/β-catenin pathway in CCl4-induced hepatic fibrosis.In vitro,lipopolysaccharide(LPS)induced hepatocyte and hepatic stellate cell(HSC)expression of AnxA1.Ac2-26 inhibited LPS-induced RAW264.7 cell activation and HSC proliferation,decreased expression ofα-SMA,collagen I and CTGF in HSCs,and inhibited expression of the Wnt/β-catenin pathway after HSC activation.These therapeutic effects were inhibited by Boc2.CONCLUSION AnxA1 inhibited liver fibrosis in mice,and its mechanism may be related to inhibition of HSC Wnt/β-catenin pathway activation by targeting formylpeptide receptors to regulate macrophage function.

Macrophage modulation with dipeptidyl peptidase-4 inhibitors:A new frontier for treating diabetic cardiomyopathy?

This editorial introduces the potential of targeting macrophage function for diabetic cardiomyopathy(DCM)treatment by dipeptidyl peptidase-4(DPP-4)inhibitors.Zhang et al studied teneligliptin,a DPP-4 inhibitor used for diabetes management,and its potential cardioprotective effects in a diabetic mouse model.They suggested teneligliptin administration may reverse established markers of DCM,including cardiac hypertrophy and compromised function.It also inhibited the NLRP3 inflammasome and reduced inflammatory cytokine production in diabetic mice.Macrophages play crucial roles in DCM pathogenesis.Chronic hyperglycemia disturbs the balance between pro-inflammatory(M1)and antiinflammatory(M2)macrophages,favoring a pro-inflammatory state contributing to heart damage.Here,we highlight the potential of DPP-4 inhibitors to modulate macrophage function and promote an anti-inflammatory environment.These compounds may achieve this by elevating glucagon-like peptide-1 levels and potentially inhibiting the NLRP3 inflammasome.Further studies on teneligliptin in combination with other therapies targeting different aspects of DCM could be suggested for developing more effective treatment strategies to improve cardiovascular health in diabetic patients.

登革2型病毒在RAW264.7细胞和THP-1细胞中复制能力及免疫激活能力的比较

目的:比较登革2型病毒(DENV2)在RAW264.7细胞和THP-1细胞中的复制能力及DENV2对这两种靶细胞的免疫激活作用。方法:将DENV2病毒液与靶细胞(RAW264.7细胞和THP-1细胞)分别孵育6h、12h、24h,孵育结束后收集细胞,Trizol法提取不同时间的细胞总RNA,检测RNA纯度和浓度后逆转录为cDNA,使用qRT-PCR检测样本中病毒目的基因DENV2 E及细胞因子IL-1β、IL-6、TNF-α、IFN-β、ISG15、CCL2的mRNA相对表达量。结果:DENV2感染RAW264.7细胞和THP-1细胞后,DENV2 E基因的表达量均显著上调(P<0.05),且呈现逐渐增加的趋势。6h、12h时,DENV2 E基因在两个靶细胞中的相对表达量一致;24h时,DENV2 E基因在RAW264.7细胞中的相对表达量显著高于THP-1细胞。与未感染DENV2组相比,DENV2感染RAW264.7细胞和THP-1细胞6h、12h、24h后,IL-1β、IL-6、TNF-α、ISG15、IFN-β、CCL2基因的相对表达量均显著升高(P<0.05),且在RAW264.7细胞中的相对表达量显著高于THP-1细胞。结论:DENV2在RAW264.7细胞中的复制能力强于THP-1细胞的复制能力,且DENV2在RAW264.7细胞中具有更强的免疫激活能力。

Effect of Mnk1 on lipopolysaccharide-induced inflammatory responses in macrophages

Objective:To investigate the effect of mitogen-activated protein kinase interaction serine kinase 1(Mnk1)gene deletion on lipopolysaccharide(LPS)-induced inflammatory response in mouse macrophages(Mφ)and the possible mechanism.Methods:Healthy male wildtype C57BL/6J(WT)and Mnk1 knockout(KO)mice were selected at 8-10 weeks of age and divided into WT+PBS,KO+PBS,WT+LPS and KO+LPS groups,and the serum levels of IL-1βwere measured by ELISA after 24 h intraperitoneal injection of PBS or LPS.The mRNA expression levels of IL-1βand Sprouty2(Spry2)in the spleen Mφwere measured by qRTPCR.Mφwas also extracted from the peritoneal cavity of two strains of mice for in vitro experiments to detect macrophage adhesion function and stimulated with equal volumes of LPS or PBS solution for 24 h,divided into WT+PBS group,KO+PBS group,WT+LPS group and KO+LPS group,and transfected with adenovirus expressing Spry2.qRT-PCR was used to detect the mRNA expression levels of LFA-1α,IL-1β,iNOS,CD206,Arg1 and Spry2 in Mφ.Mnk1,ERK1/2,P-ERK1/2,P-p38,P-JNK and Spry2 protein levels in Mφwere detected by western blot.Results:In the in vivo experiments,the concentration of IL-1βin the serum of the KO+LPS group was more significantly elevated than that of the WT+LPS group in mice injected intraperitoneally with LPS.The expression level of splenic MφIL-1βwas higher and the mRNA expression level of Spry2 was decreased in the KO+LPS group compared to the WT+LPS group.In the in vitro experiments,the mRNA expression levels of IL-1βand iNOS were elevated and those of CD206,Arg1 and Spry2 were decreased in the KO+LPS group compared with the WT+LPS group;the expression of LFA-1αwas not significantly different in the WT+PBS and WT+LPS groups,while the expression level of LFA-1αwas significantly increased in the KO+LPS group compared with the WT+LPS group.The results of the macrophage adhesion function assay showed that the adhesion rate of Mφin the KO group was increased at several time points compared to the WT group.After LPS stimulation,the expression of MφSpry2 decreased in Mnk1 KO group compared to WT group,while the expression of P-ERK1/2 increased compared to WT group.After Mφwas transfected with adenovirus overexpressing Spry2 and stimulated with LPS,MφSpry2 expression increased in the KO+AdSpry2 group and P-ERK1/2 expression decreased significantly compared to KO+AdGFP.Conclusion:Mnk1 knockdown enhances LPS-induced inflammatory responses in macrophages,and the mechanism may be related to the involvement of Spry2,a substrate of Mnk1,in regulating macrophage function.

Role of Cyclin D1b in Inducing Macrophages Toward a Tumor-associated Macrophage-like Phenotype in Murine Breast Cancer

Objective:Tumor-associated macrophages(TAMs)of the M2 phenotype are frequently associated with cancer progression.Invasive cancer cells undergoing epithelial-mesenchymal transition(EMT)have a selective advantage as TAM activators.Cyclin D1b is a highly oncogenic splice variant of cyclin D1.We previously reported that cyclin D1b enhances the invasiveness of breast cancer cells by inducing EMT.However,the role of cyclin D1b in inducing macrophage differentiation toward tumor-associated macrophage-like cells remains unknown.This study aimed to explore the relationship between breast cancer cells overexpressing cyclin Dlb and TAMs.Methods:Mouse breast cancer 4T1 cells were transfected with cyclin D1b variant and co-cultured with macrophage cells in a Transwell coculture system.The expression of characteristic cytokines in differentiated macrophages was detected using qRT-PCR,ELISA and zymography assay.Tumor-associated macrophage distribution in a transplanted tumor was detected by immunofluorescence staining.The proliferation and migration ability of breast cancer cells was detected using the cell counting kit-8(CCK-8)assay,wound healing assay,Transwell invasion assay,and lung metastasis assay.Expression levels of mRNAs were detected by qRT-PCR.Protein expression levels were detected by Western blotting.The integrated analyses of The Cancer Genome Atlas(TCGA)datasets and bioinformatics methods were adopted to discover gene expression,gene coexpression,and overall survival in patients with breast cancer.Results:After co-culture with breast cancer cells overexpressing cyclin D1b,RAW264.7 macrophages were differentiated into an M2 phenotype.Moreover,differentiated M2-like macrophages promoted the proliferation and migration of breast cancer cells in turn.Notably,these macrophages facilitated the migration of breast cancer cells in vivo.Further investigations indicated that differentiated M2-like macrophages induced EMT of breast cancer cells accompanied with upregulation of TGF-β1 and integrinβ3 expression.Conclusion:Breast cancer cells transfected with cyclin D1b can induce the differentiation of macrophages into a tumor-associated macrophage-like phenotype,which promotes tumor metastasis in vitro and in vivo.

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.

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.