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.

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.

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.

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.

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.

Exosome-derived miR-146a-5p from decidual macrophages in preeclampsia inhibits the viability and invasive ability of trophoblast cells by targeting HIF1α

Objective:To investigate the effect of exosomes secreted by decidual macrophages on trophoblast cells and their molecular mechanism.Methods:The decidual tissues of patients with preeclampsia(PE)and normal-term pregnant women were collected.Macrophages were obtained by the density gradient method and then flow cell sorting,then the exosomes were extracted.The structure of the exosomes was observed by transmission electron microscope.The expression of CD63,a marker protein of the exocrine body,was detected by western blot,and the exosomes were identified.CCK-8 was used to detect the effect of exosomes on trophoblast cell viability.Transwell migration experiment was used to detect the influence on migration ability.The expression of miR-146a-5p in exosomes was detected by qPCR.The effect of exosomes on the expression of HIF1αprotein in trophoblasts was detected by western blot and detection of the binding site between miR-146a-5p and HIF1αby double luciferase reporter gene was conducted.Results:The exosomes of macrophages present a"cake"structure with a middle depression about 30-130 nm in diameter,and CD63 is highly expressed,which conforms to the characteristics of exosomes.Compared with the normal group,the exosomes of decidual macrophages in the PE group inhibited the activity and migration of trophoblast cells(P<0.001).The expression of miR-146a-5p in the exosomes of decidual macrophages in the PE decreased significantly,and after exosomes of PE decidual macrophages treating trophoblast cells,the protein expression of HIF1αin trophoblast cells was significantly increased.There are targeted binding sites between miR-146a-5p and HIF1α.Conclusion:PE decidual macrophage exosomes can inhibit the viability and migration of trophoblast cells,which may be related to the decreased expression of miR-146a-5p in exosomes,thus promoting HIF1αprotein expression of trophoblast cells.

血红素加氧酶1(HO-1)基因敲除影响小鼠肺脏免疫细胞组成平衡并加重脂多糖诱导的急性肺损伤

目的 评价血红素加氧酶1(HO-1)基因缺失对脂多糖(LPS)诱导急性肺损伤(ALI)小鼠肺脏免疫细胞组成及炎症性损伤的影响。方法 选取C57BL/6野生型(WT)小鼠和同背景HO-1条件敲除(HO-1^(-/-))小鼠,按照随机数字法分为WT对照组、 LPS处理的WT组、 HO-1^(-/-)对照组和LPS处理的HO-1^(-/-)组。LPS处理的WT组和LPS处理的HO-1^(-/-)组分别经尾静脉注射LPS(15 mg/kg)建立ALI模型,WT对照组和HO-1^(-/-)对照组经尾静脉注射同等体积生理盐水。造模12 h后,处死小鼠并收集各组肺组织。HE染色观察肺组织病理变化。PCR检测肺组织肿瘤坏死因子α (TNF-α)、白细胞介素1β (IL-1β)和IL-6 mRNA表达。流式细胞术检测肺组织中性粒细胞(CD45^(+)CD11b^(+)Ly6G^(+)Ly6C^(-))、总单核细胞(CD45^(+)CD11b^(+)Ly6C^(hi))、促炎性单核细胞亚群(CD45^(+)CD11b^(+)Ly6C^(hi)CCR2^(hi))、总巨噬细胞(CD45^(+)CD11b^(+)F4/80^(+))、 M1巨噬细胞亚群(CD45^(+)CD11b^(+)F4/80^(+)CD86^(+))、 M2巨噬细胞亚群(CD45^(+)CD11b^(+)F4/80^(+)CD206^(+))、总T细胞(CD45^(+)CD3^(+))、 CD3^(+)CD4^(+)T细胞亚群、 CD3^(+)CD8^(+) T细胞亚群和髓源性抑制细胞(MDSC, CD45^(+)CD11b^(+)Gr1^(+))百分比。结果 与相应对照组相比,LPS处理的WT和HO-1^(-/-)小鼠,肺组织炎症损伤加重;TNF-α、 IL-1β和IL-6 mRNA水平增加;中性粒细胞、总单核细胞、促炎性单核细胞亚群、 MDSC和总巨噬细胞比例显著增加;CD3^(+)、 CD3^(+)CD4^(+)和CD3^(+)CD8^(+) T细胞比例显著降低。静息状态下,与WT对照组小鼠相比,HO-1^(-/-)对照组小鼠肺脏中性粒细胞、单核细胞、促炎性单核细胞比例增加;CD3^(+)和CD3^(+)CD8^(+) T细胞比例降低。与LPS处理的WT小鼠相比,LPS处理的HO-1^(-/-)小鼠肺组织TNF-α和IL-1β mRNA表达水平更高,总单核细胞、促炎性单核细胞亚群、 M1巨噬细胞和M1/M2比值显著增加;CD3^(+)CD8^(+) T细胞百分比显著降低。结论 HO-1的缺失影响ALI小鼠肺脏免疫系统功能,加重LPS刺激后的炎症性损伤。

抑制lncRNA TUG1下调核苷酸结合寡聚结构域样受体蛋白1炎症小体在延缓阿尔茨海默病进展的作用

目的探讨敲低长链非编码RNA(lncRNA)牛磺酸上调基因1(TUG1)抑制核苷酸结合寡聚结构域样受体蛋白1(NLRP1)炎症小体在缓解阿尔茨海默病进展中的作用。方法选取9~10周龄遗传背景为C57/BL6的野生型小鼠(WT组,10只)或淀粉样前体蛋白(APP)/早老素1(PS1)转基因小鼠(30只)。APP/PS1转基因小鼠随机分为模型(model)组,模型+敲低lncRNA TUG1组[model+lncRNA TUG1短发夹RNA(shRNA)组]和model+shRNA非靶标(NT)组,每组10只。分别采集12周龄第1天(3月龄)和32周龄第1天(8月龄)小鼠外周血和脑皮质组织,并分离皮质中的原代小胶质细胞和原代星形胶质细胞,每个时间点每组5只小鼠。Real-time PCR分别测定3月龄和8月龄上述4个分组小鼠脑皮质组织和原代小胶质细胞中lncRNA TUG1和巨噬细胞移动抑制因子(MIF)mRNA的水平,以及原代星形胶质细胞中补体蛋白C1r和C1s mRNA的水平。ELISA法测定其外周血浆中MIF含量。对3月龄和8月龄小鼠脑皮质原代小胶质细胞和原代星形胶质细胞共培养。CCK-8法测定上述2种细胞的增殖能力。Western blotting分别测定3月龄和8月龄上述4个分组小鼠脑皮质组织中MIF、白细胞介素1β前体(pro-IL-1β)、凋亡相关斑点样蛋白(ASC)、Caspase-1(p20)、Caspase-1(full)、NLRP1及NLRP3蛋白的表达水平。采用免疫荧光染色法测定8月龄各分组小鼠脑皮质组织中β淀粉样蛋白(Aβ)表达。结果3月龄和8月龄时,与WT组小鼠相比,model组小鼠脑皮质组织和原代小胶质细胞中lncRNA TUG1和MIF相对表达水平显著上调,原代小胶质细胞和原代星形胶质细胞增殖能力增强(P<0.05)。与model组相比,model+lncRNA TUG1 shRNA组小鼠脑皮质组织和原代小胶质细胞中lncRNA TUG1和MIF的相对表达水平显著降低,原代小胶质细胞和原代星形胶质细胞增殖能力降低(P<0.05)。与WT组相比,model组小鼠外周血浆中MIF含量显著升高;小鼠脑皮质组织中pro-IL-1β、ASC、Caspase-1(p20)、Caspase-1(full)、NLRP1以及NLRP3的蛋白表达水平显著升高;Aβ免疫荧光强度明显增强(P<0.05)。与model组相比,model+lncRNA TUG1 shRNA组小鼠外周血浆中MIF含量显著降低;小鼠脑皮质组织中pro-IL-1β、ASC、Caspase-1(p20)、Caspase-1(full)和NLRP1的蛋白表达水平显著降低,Aβ免疫荧光强度明显降低(P<0.05),而NLRP3蛋白质的表达水平无明显变化(P>0.05)。与model组相比,model+shRNA NT组小鼠上述所有检测指标差异均无显著性(P>0.05)。结论APP/PS1转基因小鼠脑皮质组织和原代小胶质细胞中lncRNA TUG1和MIF因子表达上调与脑皮质内NLRP1炎症小体激活成正相关,敲低lncRNA TUG1可缓解阿尔茨海默病的进展。

补体因子H相关蛋白1促进巨噬细胞分泌肿瘤坏死因子-α调控足细胞增殖和迁移实验研究

目的:探讨补体因子H相关蛋白1(CFHR1)通过巨噬细胞分泌肿瘤坏死因子-α(TNF-α)调控足细胞增殖和迁移的作用。方法:体外培养人单核巨噬细胞和人肾足细胞。巨噬细胞分为对照组和CFHR1干预组,分别进行牛血清白蛋白或CFHR1重组蛋白干预24 h,ELISA法测定上清液TNF-α水平。足细胞分为空白组、TNF-α干预组、对照上清液干预组、CFHR1上清液干预组、CFHR1上清液+TNF-α中和抗体干预组。CCK8法检测各组细胞增殖。Transwell法检测各组细胞迁移。Wb法检测各组细胞中相关蛋白变化。结果:巨噬细胞的CFHR1干预组上清液中TNF-α含量显著增加(P<0.05)。与空白组比较,TNF-α干预组、CFHR1上清液干预组的细胞增殖比率和迁移数量均显著降低(均P<0.05)。与CFHR1上清液干预组比较,CFHR1上清液+TNF-α中和抗体干预组的细胞增殖比率和迁移数量均显著提高(均P<0.05)。与空白组比较,TNF-α干预组、CFHR1上清液干预组的足细胞裂孔膜蛋白(Nephrin)、足突蛋白(Podocin)、纤维状肌动蛋白(F-Actin)、整合素α3β1蛋白(α3β1)表达均显著降低(均P<0.05)。与CFHR1上清液干预组比较,CFHR1上清液+TNF-α中和抗体干预组的Nephrin、Podocin、F-actin、α3β1蛋白表达均显著增多(均P<0.05)。结论:CFHR1促进巨噬细胞分泌的TNF-α可显著抑制足细胞增殖水平和迁移能力,这可能是高浓度CFHR1促进肾病综合征发展的途径。

IL-1β通过激活ERK1/2信号通路抑制人脐带间充质干细胞CD200表达抑制巨噬细胞M2极化

目的探究白细胞介素1β(IL-1β)调控人脐带间充质干细胞CD200表达及其对巨噬细胞极化的影响及作用机制。方法无血清培养基分离培养获得人脐带间充质干细胞(hUC-MSC),形态学观察及流式细胞术检测CD73、CD90、CD105、CD14、CD34、CD45、人类白细胞抗原DR(HLA-DR)的表达,确定间充质干细胞属性;20 ng/mL IL-1β处理hUC-MSC 24 h,流式细胞术检测CD200阳性细胞率,实时定量PCR和Western blot法检测CD200 mRNA和蛋白表达水平;佛波酯(PMA)诱导THP-1巨噬细胞活化,并与IL-1β处理感染CD200过表达慢病毒的hUC-MSC共培养,流式细胞术检测CD11c和CD206阳性细胞比例;IL-1β联合细胞外信号调节激酶1/2(ERK1/2)特异性抑制剂PD98059处理hUC-MSC,Western blot法检测细胞丝裂原激活蛋白激酶(MAPK)信号分子与CD200的表达。结果IL-1β显著下调hUC-MSC CD200蛋白表达与CD200阳性细胞率;过表达CD200显著上调hUC-MSC CD200表达,且CD200过表达hUC-MSC提高巨噬细胞CD206阳性细胞比率;IL-1β激活hUC-MSC的ERK1/2信号通路,PD98059上调IL-1β处理后hUC-MSC中CD200的蛋白表达。结论IL-1β通过激活ERK1/2信号通路抑制CD200的表达,进而抑制hUC-MSC对巨噬细胞向M2型极化的促进作用。

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。

NUSAP1在肿瘤相关巨噬细胞中的表达及对非小细胞肺癌的影响

目的探究NUSAP1在肿瘤相关巨噬细胞中表达对非小细胞肺癌的影响机制。方法使用Western blot检测检测人癌和癌周巨噬细胞中NUSAP1、p-PI3K以及MMP-9的相对蛋白表达量;使用慢病毒感染M2巨噬细胞,构建骨髓诱导M2与人非小细胞肺癌细胞株Lewis共培养体外模拟NSCLC肿瘤微环境,使用Western blot检测M2巨噬细胞中NUSAP1、p-PI3K以及MMP-9的相对蛋白表达量。使用细胞划痕实验检测非小细胞肺癌细胞的迁移能力。结果人体样本Western blot检测结果显示非小细胞肺癌组织中NUSAP1,PI3K与MMP-9的相对蛋白表达量显著高于癌周组织(P<0.05);体外实验通过小鼠巨噬细胞与Lewis共培养以模拟体内肿瘤环境,Western blot检测慢病转染敲低NUSAP1后p-PI3K与MMP-9均表达降低(P<0.05),上调NUSAP1后p-PI3K与MMP-9表达均升高(P<0.05)。MMP-9过表达(OV-MMP-9)抵消了由于敲低NUSAP1所造成的MMP-9表达水平降低,同时shRNA-NUSAP1+ovMMP-9组侵袭率明显高于shRNA-NUSAP1+OVNC组(P<0.05)。shRNANUSAP1(NUSAP1敲低)组比shNUSAP1组的迁移宽度明显增加,说明迁移能力受限;在敲低NUSAP1的基础尚过表达MMP-9(OV-MMP-9)后迁移能力明显变强,迁移宽度显著变小(P<0.05)。结论NUSAP1在肿瘤相关巨噬细胞中通过促进PI3K通路的激活及MMP-9的表达从而促进非小细胞肺癌细胞的迁移。

M2 macrophages mediate fibrotic scar formation in the early stages after cerebral ischemia in rats

In the central nervous system, the formation of fibrotic scar after injury inhibits axon regeneration and promotes repair. However, the mechanism underlying fibrotic scar formation and regulation remains poorly understood. M2 macrophages regulate fibrotic scar formation after injury to the heart, lung, kidney, and central nervous system. However, it remains to be clarified whether and how M2 macrophages regulate fibrotic scar formation after cerebral ischemia injury. In this study, we found that, in a rat model of cerebral ischemia induced by middle cerebral artery occlusion/reperfusion, fibrosis and macrophage infiltration were apparent in the ischemic core in the early stage of injury(within 14 days of injury). The number of infiltrated macrophages was positively correlated with fibronectin expression. Depletion of circulating monocyte-derived macrophages attenuated fibrotic scar formation. Interleukin 4(IL4) expression was strongly enhanced in the ischemic cerebral tissues, and IL4-induced M2 macrophage polarization promoted fibrotic scar formation in the ischemic core. In addition, macrophage-conditioned medium directly promoted fibroblast proliferation and the production of extracellular matrix proteins in vitro. Further pharmacological and genetic analyses showed that sonic hedgehog secreted by M2 macrophages promoted fibrogenesis in vitro and in vivo, and that this process was mediated by secretion of the key fibrosis-associated regulatory proteins transforming growth factor beta 1 and matrix metalloproteinase 9. Furthermore, IL4-afforded functional restoration on angiogenesis, cell apoptosis, and infarct volume in the ischemic core of cerebral ischemia rats were markedly impaired by treatment with an sonic hedgehog signaling inhibitor, paralleling the extent of fibrosis. Taken together, our findings show that IL4/sonic hedgehog/transforming growth factor beta 1 signaling targeting macrophages regulates the formation of fibrotic scar and is a potential therapeutic target for ischemic stroke.

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.

Mudskipper interleukin-34 modulates the functions of monocytes/macrophages via the colony-stimulating factor-1 receptor 1

Interleukin-34(IL-34)is a novel cytokine that plays an important role in innate immunity and inflammatory processes by binding to the colonystimulating factor-1 receptor(CSF-1R).However,information on the function of IL-34 in fish remains limited.In the present study,we identified an IL-34 homolog from mudskippers(Boleophthalmus pectinirostris).In silico analysis showed that the mudskipper IL-34(BpIL-34)was similar to other known IL-34 variants in sequence and structure and was most closely related to an orange-spotted grouper(Epinephelus coioides)homolog.BpIL-34 transcripts were constitutively expressed in various tissues,with the highest level of expression found in the brain.Edwardsiella tarda infection significantly up-regulated the mRNA expression of BpIL-34 in the mudskipper tissues.The recombinant mature BpIL-34 peptide(rBpIL-34)was purified and used to produce anti-rBpIL-34 IgG.Western blot analysis combined with PNGase F digestion revealed that native BpIL-34 in monocytes/macrophages(MOs/MФs)was N-glycosylated.In vitro,rBpIL-34 treatment enhanced the phagocytotic and bactericidal activity of mudskipper MOs/MФs,as well as the mRNA expression of pro-inflammatory cytokines like tumor necrosis factorα(BpTNF-α)and BpIL-1βin these cells.Furthermore,the knockdown of mudskipper CSF-1R1(BpCSF-1R1),but not mudskipper BpCSF-1R2,significantly inhibited the rBpIL-34-mediated enhanced effect on MO/MФfunction.In conclusion,our results indicate that mudskipper BpIL-34 modulates the functions of MOs/MФs via BpCSF-1R1.