乌帕替尼对氧糖剥夺/复氧后BV2细胞极化的影响

目的 研究乌帕替尼对氧糖剥夺再复氧(OGD/R)后BV2小胶质细胞极化及炎症的影响,并探讨其作用机制.方法 实验分对照组、OGD组和乌帕替尼组3组.BV2细胞经OGD/R处理后,噻唑蓝试剂(MTT)检测细胞生存率,划痕实验观察细胞迁移能力,实时荧光定量多聚核苷酸链式反应(qPCR)检测BV2细胞M1型极化标志物(CD1...     

白头翁皂苷A3通过M2型巨噬细胞提高人结肠癌SW480细胞对5-FU的化疗敏感性

目的:观察白头翁皂苷A3(A3)通过干预巨噬细胞极化增强人结肠癌SW480细胞对5-氟尿嘧啶(5-FU)化疗的敏感性,并探讨其作用机制。方法:采用CCK8法检测A3对人单核THP-1细胞存活率的影响,确定A3的安全作用浓度;采用佛波酯(PMA)诱导THP-1细胞分化为M0型巨噬细胞,将M0型巨噬细胞分为M0对照组,M2模型组,A3低、中、高剂量干预组。其中M2模型组给予20 μg·L^-1IL-4与20 μg·L^-1IL-13进行造模,A3干预组在造模的同时给予低、中、高剂量(50,75,100 mg·L^-1)A3进行干预。采用流式细胞术检测M2型巨噬细胞表面抗原CD206的表达;采用RT-PCR法检测M2型巨噬细胞极化因子CD206、IL-10、CCL22、CCL18 mRNA的表达;采用Western blot法检测细胞内p-STAT6、CD206、IL-10、CCL22蛋白的表达。A3干预巨噬细胞M2型极化后的细胞上清液作为条件培养基用于考察SW480细胞对5-FU的化疗敏感性,采用CCK8法检测SW480细胞的存活率;采用Annexin-FITC/PI双染法及Western blot法检测SW480细胞凋亡水平,以及Bax、Cleaved Caspase-3蛋白的表达。结果:A3在50,75,100 mg·L^-1浓度时对THP-1细胞存活率没有显著影响。A3呈剂量依赖性减少CD206阳性细胞表达比例,下调p-STAT6、CD206、IL-10、CCL22、CCL18基因与蛋白的表达(P<0.05,P<0.01)。A3干预巨噬细胞M2型极化后的条件培养基显著提高了SW480细胞对5-FU的敏感性,表现为SW480细胞的存活率下降、凋亡率升高,以及促凋亡蛋白Bax、Cleaved Caspase-3表达上调(P<0.05)。结论:A3能够减弱M2型巨噬细胞对SW480细胞凋亡的抑制作用从而提高SW480细胞对5-FU的化疗敏感性,作用机制可能与A3调控STAT6信号通路抑制巨噬细胞M2型极化有关。     

Isoliquiritigenin,a flavonoid from licorice,blocks M2 macrophage polarization in colitis-associated tumorigenesis through downregulating PGE2 and IL-6

M2 macrophage polarization is implicated in colorectal cancer development. Isoliquiritigenin (ISL), a flavonoid from licorice, has been reported to prevent azoxymethane (AOM) induced colon carcinogenesis in animal models. Here, in a mouse model of colitis-associated tumorigenesis induced by AOM/dextran sodium sulfate (DSS), we investigated the chemopreventive effects of ISL and its mechanisms of action. Mice were treated with AOM/DSS and randomized to receive either vehicle or ISL (3, 15 and 75 mg/kg). Tumor load, histology, immunohistochemistry, and gene and protein expressions were determined. Intragastric administration of ISL for 12 weeks significantly decreased colon cancer incidence, multiplicity and tumor size by 60%, 55.4% and 42.6%, respectively. Moreover, ISL inhibited M2 macrophage polarization. Such changes were accompanied by downregulation of PGE₂ and IL-6 signaling. Importantly, depletion of macrophages by clodronate (Clod) or zoledronic acid (ZA) reversed the effects of ISL. In parallel, in vitro studies also demonstrated that ISL limited the M2 polarization of RAW264.7 cells and mouse peritoneal macrophages with concomitant inactivation of PGE₂/PPARδ and IL-6/STAT3 signaling. Conversely, exogenous addition of PGE₂ or IL-6, or overexpression of constitutively active STAT3 reversed ISL-mediated inhibition of M2 macrophage polarization. In summary, dietary flavonoid ISL effectively inhibits colitis-associated tumorigenesis through hampering M2 macrophage polarization mediated by the interplay between PGE₂ and IL-6. Thus, inhibition of M2 macrophage polarization is likely to represent a promising strategy for chemoprevention of colorectal cancer.     

Apolipoprotein A-I inhibits LPS-induced atherosclerosis in ApoE?/? mice possibly via activated STAT3-mediated upregulation of tristetraprolin

Aim:

To investigate the effects of the major component of high-density lipoprotein apolipoprotein A-I (apoA-I) on the development of atherosclerosis in LPS-challenged ApoE^−/− mice and the underlying mechanisms.

Methods:

Male ApoE-KO mice were daily injected with LPS (25 μg, sc) or PBS for 4 weeks. The LPS-challenged mice were intravenously injected with rAAV-apoA-I-GFP or rAAV-GFP. After the animals were killed, blood, livers and aortas were collected for biochemical and histological analyses. For ex vivo experiments, the abdominal cavity macrophages were harvested from each treatment group of mice, and cultured with autologous serum, then treated with LPS.

Results:

Chronic administration of LPS in ApoE^−/− mice significantly increased the expression of inflammatory cytokines (TNF-α, IL-1β, IL-6, and MCP-1), increased infiltration of inflammatory cells, and enhanced the development of atherosclerosis. In LPS-challenged mice injected with rAAV-apoA-I-GFP, viral particles and human apoA-I were detected in the livers, total plasma human apoA-I levels were grammatically increased; HDL-cholesterol level was significantly increased, TG and TC were slightly increased. Furthermore, overexpression of apoA-I significantly suppressed the expression of proinflammatory cytokines, reduced the infiltration of inflammatory cells, and decreased the extent of atherosclerotic lesions. Moreover, overexpression of apoA-I significantly increased the expression of the cytokine mRNA-destabilizing protein tristetraprolin (TTP), and phosphorylation of JAK2 and STAT3 in aortas. In ex vivo mouse macrophages, the serum from mice overexpressing apoA-I significantly increased the expression of TTP, accompanied by accelerated decay of mRNAs of the inflammatory cytokines.

Conclusion:

ApoA-I potently suppresses LPS-induced atherosclerosis by inhibiting the inflammatory response possibly via activation of STAT3 and upregulation of TTP.     

Biomimetic carbon monoxide delivery based on hemoglobin vesicles ameliorates acute pancreatitis in mice via the regulation of macrophage and neutrophil activity

Macrophages play a central role in various inflammatory disorders and are broadly divided into two subpopulations, M1 and M2 macrophage. In the healing process in acute inflammatory disorders, shifting the production of M1 macrophages to M2 macrophages is desirable, because M1 macrophages secrete pro-inflammatory cytokines, whilst the M2 variety secrete anti-inflammatory cytokines. Previous findings indicate that when macrophages are treated with carbon monoxide (CO), the secretion of anti-inflammatory cytokine is increased and the expression of pro-inflammatory cytokines is inhibited, indicating that CO may have a potential to modulate the production of macrophages toward the M2-like phenotype. In this study, we examined the issue of whether CO targeting macrophages using a nanotechnology-based CO donor, namely CO-bound hemoglobin vesicles (CO-HbV), modulates their polarization and show therapeutic effects against inflammatory disorders. The results showed that the CO-HbV treatment polarized a macrophage cell line toward an M2-like phenotype. Furthermore, in an in vivo study using acute pancreatitis model mice as a model of an inflammatory disease, a CO-HbV treatment also tended to polarize macrophages toward an M2-like phenotype and inhibited neutrophil infiltration in the pancreas, resulting in a significant inflammation. In addition to the suppression of acute pancreatitis, CO-HbV diminished a subsequent pancreatitis-associated acute lung injury. This could be due to the inhibition of the systemic inflammation, neutrophil infiltration in the lungs and the production of HMGB-1. These findings suggest that CO-HbV exerts superior anti-inflammatory effects against inflammatory disorders via the regulation of macrophage and neutrophil activity.     

TAK-242通过调控JAK2/STAT3通路抑制小鼠心肌缺血再灌注损伤炎症反应

目的：探讨Toll样受体4拮抗剂TAK-242抑制小鼠心肌缺血/再灌注损伤（ischemia/reperfusion,I/R）炎症反应的分子机制。方法：选用48只雄性C57BL/6小鼠随机分为4组：假手术组（sham）、模型组（I_30min /R_24h）、给药组[I/R+TAK-242（3 mg·kg^-1）]、干预组[I/R+TAK-242+AG490（15 mg·kg^-1）]。再灌注24 h后心脏超声检测小鼠心功能,氯化三苯基四氮唑（TTC）染色法测定心肌梗死面积,HE染色观察心肌病理改变,WB检测心肌JAK2/STAT3磷酸化水平,ELISA检测血清IL-6、TNF-α、IL-10和高迁移率族蛋白B1（HMGB1）浓度。结果：与sham组比较,I/R组小鼠左心室收缩期直径（LVIDs）延长（P<0.01）,左心室射血分数（LVEF）和左心室短轴缩短分数（LVFS）显著降低（P<0.001或P<0.01）,心梗面积明显增加并出现心肌炎性浸润,心肌p-JAK2/p-STAT3表达明显升高（P<0.01或P<0.05）,血清IL-6、IL-10、TNF-α和HMGB1水平显著升高（P<0.001或P<0.01）。与I/R组比较,TAK-242给药组小鼠LVIDs缩短（P<0.05）,LVEF和LVFS显著升高（P<0.01或P<0.05）,心梗面积缩小（P<0.01）,心肌炎症浸润减轻,心肌p-JAK2/p-STAT3表达降低（P<0.01或P<0.05）,血清IL-6和TNF-α水平明显下降（P<0.001或P<0.01）,而IL-10和HMGB1浓度进一步升高（P<0.01）。与TAK-242给药组比较,AG490干预可显著加强TAK-242治疗作用,包括心肌收缩功能增强,心梗面积缩小及炎性浸润程度减轻,心肌p-JAK2/p-STAT3表达降低（P<0.05）,血清IL-6、TNF-α浓度下降而IL-10、HMGB1浓度升高（P<0.01或P<0.05）。结论： Toll样受体4拮抗剂TAK-242抑制小鼠I/R炎症反应与JAK2/STAT3信号通路失活有关。     

骨髓间充质干细胞来源外泌体对炎症微环境中巨噬细胞 表型及软骨细胞的调控作用

目的 研究骨髓间充质干细胞来源外泌体（BMSCs-Exo）在炎症微环境中对巨噬细胞表型极化及软骨修复的调控作用。方法 差速离心法提取BMSCs-Exo，透射电镜观察外泌体形态，Western blot检测Alix、TSG101表达；使用不同浓度的BMSCs-Exo（10 μg/mL 和50 μg/mL）处理M1巨噬细胞及IL-1β刺激的软骨细胞，CCK-8测定BMSCs-Exo促巨噬细胞增殖能力，Western blot和qRT-PCR验证BMSCs-Exo对M1型巨噬细胞表型极化的影响，炎症相关基因IL-1β、IL-6的表达水平，以及成软骨相关因子COL II、MMP-13、TGF-β1的表达水平。结果 BMSCs-Exo为圆形双层囊泡，表达Alix、TSG101，可促进巨噬细胞增殖。与对照组比较，M1型巨噬细胞经BMSCs-Exo处理后，M1型极化标记物（iNOS）的表达水平降低，M2型极化标记物（Arg-1）的表达水平升高（P<0.05）；炎症相关基因IL-1β、IL-6的表达水平显著降低（P<0.05），炎症软骨细胞中的COL II、TGF-β1表达升高，MMP-13表达水平降低（P<0.05）。结论 BMSCs-Exo可调控M1型巨噬细胞向M2型巨噬细胞极化，降低炎症因子表达水平，促进炎症微环境中软骨修复。     

The key role of macrophage depolarization in the treatment of COPD with ergosterol both in vitro and in vivo

Macrophages are the most abundant immune cells in the lung, which play an important role in COPD. The anti-inflammatory and anti-oxidation of ergosterol are well documented. However, the effect of ergosterol on macrophage polarization has not been studied. The objective of this work was to investigate the effect of ergosterol on macrophage polarization in CSE-induced RAW264.7 cells and Sprague-Dawley (SD) rats COPD model. Our results demonstrate that CSE-induced macrophages tend to the M1 polarization via increasing ROS, IL-6 and TNF-α, as well as increasing MMP-9 to destroy the lung construction in both RAW264.7 cells and SD rats. However, treatment of RAW264.7 cells and SD rats with ergosterol inhibited CSE-induced inflammatory by decreasing ROS, IL-6 and TNF-α, and increasing IL-10 and TGF-β, shuffling the dynamic polarization of macrophages from M1 to M2 both in vitro and in vivo. Ergosterol also decreased the expression of M1 marker CD40, while increased that of M2 marker CD163. Moreover, ergosterol improved the lung characters in rats by decreasing MMP-9. Furthermore, ergosterol elevated HDAC3 activation and suppressed P300/CBP and PCAF activation as well as acetyl NF-κB/p65 and IKKβ, demonstrating that HDAC3 deacetylation was involved in the effect of ergosterol on macrophage polarization. These results also provide a proof in immunoregulation of ergosterol for therapeutic effects of cultured C. sinensis on COPD patients.     

Follistatin like protein-1 modulates macrophage polarization and aggravates dextran sodium sulfate-induced colitis

Follistatin-like protein 1 (FSTL1) is a pleiotropic cytokine involved in multiple processes including organ development, carcinogenesis, metastasis and so on. Some recent studies have suggested a possible role of FSTL1 in the inflammatory diseases. We for the first time tried to unravel its effect on the colitis, and explore the possible mechanisms. Here we found that FSTL1 was upregulated in active human and murine colitis. It facilitated proinflammatory M1 polarization of macrophages and inhibited the M2 anti-inflammatory phenotype, leading to excessive production of multiple inflammatory cytokines in vitro and in vivo. Haplodeletion of FSTL1 in mice significantly reduced the clinical and histological activity of colitis. Most importantly, macrophage depletion diminished the difference between DSS-treated WT and FSTL1^+/− mice. Altogether, our results suggested that FSTL1 may also serve as an important contributor in the colonic inflammation. The possible mechanism may be related to its modulation on macrophage polarization.     

Naoxintong accelerates diabetic wound healing by attenuating inflammatory response

ContextNaoxintong (NXT), a prescribed traditional Chinese medicine, widely used in cerebrovascular and cardiovascular diseases, could be effective in diabetic wounds.ObjectiveThis study evaluates the wound healing activity of NXT by employing an excisional wound splinting model.Materials and methodsNXT was dissolved in saline and given daily by gavage. Wounds were induced at the dorsum of non-diabetic (db/+) and diabetic (db/db) mice and treated with saline or 700 mg/kg/d NXT for 16 days. Wound closure was measured every four days. Extracellular matrix (ECM) remodelling, collagen deposition, leukocyte infiltration and expression of Col-3, CK14, CXCL1, CXCL2, MPO, Ly6G, CD68, CCR7, CD206, p-JAK1, p-STAT3 and p-STAT6 was analysed.ResultsNXT significantly accelerated rate of wound closure increased from 70% to 84%, accompanied by up-regulation of collagen deposition and ECM at days 16 post-injury. Moreover, NXT alleviated neutrophil infiltration, accompanied by down-regulation of CXCL1 and CXCL2 mRNA expression. In addition, NXT markedly augmented neutrophil efferocytosis. In diabetic wounds, the levels of M1 marker gene (CCR7) increased, while M2 marker gene (CD206) decreased, demonstrating a pro-inflammatory shift. Application of NXT increased M2 macrophage phenotype in db/db mice. Mechanistically, NXT treatment increased expression level of p-STAT3 and p-STAT6 at days 3 post-injury, indicating NXT mediated macrophages towards M2 phenotype and alleviated inflammation in diabetic wounds by activation of STAT3 and STAT6.ConclusionsOur study provides evidence that NXT accelerates diabetic wound healing by attenuating inflammatory response, which provides an important basis for use of NXT in the treatment of chronic diabetic wound healing.     

NecroX-5 ameliorates inflammation by skewing macrophages to the M2 phenotype

This study aimed to evaluate the role of NecroX-5, a powerful anti-inflammatory agent, on the functional plasticity of macrophages and the possible underlying mechanism using RAW264.7 cells, thioglycollate-elicited peritoneal macrophages from C57BL/6 mice, and a murine model of dextran sodium sulfate (DSS)-induced colitis. The change in cell morphology was examined by scanning electron microscopy. The expression of CD206, arginase (Arg)-1, and inducible nitric oxide synthase (iNOS) were examined by western blotting. The production of inflammatory cytokines was detected by enzyme-linked immunosorbent assays and statistical comparisons were made. The results showed that treatment of RAW264.7 cells with NecroX-5 caused an elongated shape in comparison to non-treated cells. The expression levels of macrophage mannose receptor CD206 and Arg-1, specific markers of M2 cells, were significantly upregulated by NecroX-5 treatment, while those of iNOS (M1 macrophages) was decreased. In addition, NecroX-5 significantly reduced the secretion of inflammatory cytokines, while interleukin (IL)-4 and IL-13 secretion in the supernatant was significantly enhanced. Treatment with NecroX-5 considerably ameliorated the progression of DSS-induced colitis and significantly inhibited the mRNA expression of pro-inflammatory cytokines, including tumor necrosis factor-α and IL-1β. Taken together, our findings demonstrated that NecroX-5 might dampen inflammation by switching the M1 phenotype to the M2 phenotype due to IL-4 and IL-13 induction.     

Cathelicidin-WA polarizes E. coli K88-induced M1 macrophage to M2-like macrophage in RAW264.7 cells

Immune cells - macrophages induced by E. coli K88 will lead to a pro-inflammatory response, which is important in host defense. Cathelicidin-WA (CWA) is an efficient antimicrobial peptide (AMP) and can exert immunomodulatory properties. Many studies have demonstrated that AMP can modulate cellular subsets but whether CWA can regulate macrophage polarization by transferring E. coli K88-induced M1 macrophage towards M2 one that of anti-inflammation remains unclear. In this study, E. coli K88 increased the expression of pro-inflammatory cytokines interleukin-6, interleukin-1β, tumor necrosis factor-α and chemokine CCL3 in RAW264.7 cells with a time-dependent manner, as well as the expression of reactive oxygen species (ROS) and inducible nitric oxide synthase (iNOS). On this basis, CWA significantly decreased the pro-inflammatory molecules but increased the anti-inflammatory mediators interleukin-4, interleukin-10 and other M2-related genes in E. coli K88-induced macrophages. Western blot analysis indicated that CWA suppressed the expression of TLR-4 and the phosphorylation of STAT1 and NF-κB which modulated M1 macrophage while induced the phosphorylation of STAT6 which activated M2 macrophage. Double staining of M1-specific CD86 and M2-specific CD206 also proved the hypothesis. These results suggested that CWA might dampen the inflammation by modulating M1 phenotype to M2 phenotype in E. coli K88-induced macrophages.     

SOCS1 hypermethylation mediated by DNMT1 is associated with lipopolysaccharide-induced inflammatory cytokines in macrophages

Macrophages activation which releases the pro-inflammatory cytokines is an essential event in the process of inflammation. SOCS1 has been shown to act as a negative regulator of cytokine signals and plays a key role in the suppression of tissue injury and inflammatory diseases. DNA methylation mediated by specific DNA methyltransferases1 (DNMT1) which contributes to the epigenetic silencing of multiple genes. SOCS1 promoter hypermethylation is by far the best categorized epigenetic change in tumors. Our study with a view to investigate whether the loss of SOCS1 due to SOCS1 promoter methylation was involved in the course of inflammatory cytokines released from lipopolysaccharide (LPS)-stimulated macrophages. Here, we found that treatment of LPS-induced RAW264.7 macrophage cells with the DNA methylation inhibitor 5-aza-2′-deoxycytidine (5-azadC) reduced aberrant promoter hypermethylation of SOCS1 and prevented the loss of the expression of SOCS1 in macrophages which secret inflammatory cytokines. Knockdown of DNMT1 gene not only attenuated the SOCS1 gene promoter methylation but also up-regulated the expression of SOCS1 in activated RAW264.7 cells. Furthermore, silencing of DNMT1 prevented the activation of JAK2/STAT3 pathway in LPS-induced RAW264.7 cells. These studies demonstrated that DNMT1-mediated SOCS1 hypermethylation caused the loss of SOCS1 expression results in negative regulation of activation of the JAK2/STAT3 pathway, and enhanced the release of LPS-induced pro-inflammatory cytokines such as TNF-α and IL-6 in macrophages.     

4-Methoxylonchocarpin attenuates inflammation by inhibiting lipopolysaccharide binding to Toll-like receptor of macrophages and M1 macrophage polarization

The roots of Abrus precatorius (AP, Fabaceae) have traditionally been used in Vietnam and China for the treatment of inflammatory diseases such as stomatitis, asthma, bronchitis, and hepatitis. Therefore, in this study, we isolated 4-methoxylonchocarpin (ML), an anti-inflammatory compound present in AP, and studied its anti-inflammatory effects in mice with 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis. In lipopolysaccharide (LPS)-stimulated macrophages, ML was found to inhibit nuclear factor (NF)-κB activation and tumor necrosis factor (TNF) and interleukin (IL)-6 expression by inhibiting LPS binding to Toll-like receptor 4 (TLR4) in vitro. Oral administration of ML in mice with TNBS-induced colitis suppressed colon shortening and colonic myeloperoxidase activity. ML treatment significantly inhibited the activation of nuclear factor (NF)-κB and phosphorylation of transforming growth factor β-activated kinase 1 in the colon. Treatment with ML also inhibited TNBS-induced expression of IL-1β, IL-17A, and TNF. While ML reduced the TNBS-induced expression of M1 macrophage markers such as arginase-2 and TNF, it was found to increase the expression of M2 macrophage markers such as arginase-1 and IL-10. In conclusion, oral administration of ML attenuated colitis in mice by inhibiting the binding of LPS to TLR4 on immune cells and increasing the polarization of M1 macrophages to M2 macrophages.     

信号传导与转录激活子4 信号通路在脂肪酶/Toll 样受体4调控M1/M2 型巨噬细胞分化的作用及机制

目的探讨信号传导与转录激活子4(STAT4)信号通路在脂肪酶(LPS)/Toll样受体4(TLR4)调控M1/M2型巨噬细胞分化的作用及机制。方法用野生型和STAT4-KO小鼠建立动脉内膜拉伤-增生模型,在术后1、3、7和14 d用流式细胞术分析免疫细胞M1/M2型巨噬细胞在外周血内的百分比变化。用免疫荧光双染检测M1,M2型巨噬细胞的表达。用实时荧光定量PCR(q-RT PCR)检测血管组织中STAT4和TLR4表达;酶联免疫吸附试验(ELISA)检测血管生长因子VEGF、PDGF-BB变化。从STAT4KO和蛋白质印迹法小鼠骨髓分离CD11b+细胞,用集落刺激因子GM-CSF和LPS处理,细胞实验分为WT con组、WT+LPS刺激组、STAT4KO con组、STAT4KO+LPS刺激组。观察巨噬细胞的分化情况。结果与野生组相比,STAT4-KO组在术后1、3、7和14天时M1 型巨噬细胞F4/80+iNOS+,F4/80+IL-12的细胞百分比降低(P<0.05),而M2型巨噬细胞F4/80+Arg-1+和F4/80+CD206+ 的细胞百分比明显升高(P<0.05)。STAT4-KO组的M1,M2型巨噬细胞阳性表达率(9.42±0.41)%、(89.48±10.43)%与野生组(11.14±1.49)%、(48.73±5.89)%比较,差异有统计学意义(P<0.05)。STAT4 和TLR4 在STAT4-KO 组［(0.23±0.04)、(0.47±0.06)］中的表达量明显较野生组［(1.31±0.07)、(0.89±0.08)］低(P<0.05)。VEGF、PDGF-BB 在STAT4-KO 组［(9.28±1.02)、(10.56±1.62)］中的表达量明显较野生组［(3.14±0.91)、(4.23±0.84)］高(P<0.05)。M2型巨噬细胞的诱导因子(IL-4)及分泌因子(IL-10)在STAT4KO+LPS 刺激组、WT+LPS 刺激组、STAT4KO con 组中的表达量明显较WT con 组高(F=13.412,F=15.012,P<0.05),其中STAT4KO+LPS刺激组表达量最为显著。结论STAT4信号通路可以促进抑制M1型巨噬细胞和增强M2型巨噬细胞分化。其作用机制可能是通过LPS/TLR4的结合。     

Immunomodulatory activity of andrographolide on macrophage activation and specific antibody response

Aim:

To investigate the immunomodulatory effects of andrographolide on both innate and adaptive immune responses.

Methods:

Andrographolide (10 μg/mL in vitro or 1 mg/kg in vivo) was used to modulate LPS-induced classical activated (M1) or IL-4-induced alternative activated (M2) macrophages in vitro and humor immune response to HBsAg in vivo. Cytokine gene expression profile (M1 vs M2) was measured by real-time PCR, IL-12/IL-10 level was detected by ELISA, and surface antigen expression was evaluated by flow cytometry, whereas phosphorylation level of ERK 1/2 and AKT was determined by Western blot. The level of anti-HBs antibodies in HBsAg immunized mice was detected by ELISA, and the number of HBsAg specific IL-4-producing splenocyte was enumerated by ELISPOT.

Results:

Andrographolide treatment in vitro attenuated either LPS or IL-4 induced macrophage activation, inhibited both M1 and M2 cytokines expression and decreased IL-12/IL-10 ratio (the ratio of M1/M2 polarization). Andrographolide down-regulated the expression of mannose receptor (CD206) in IL-4 induced macrophages and major histocompability complex/costimulatory molecules (MHC I, CD40, CD80, CD86) in LPS-induced macrophages. Correspondingly, anti-HBs antibody production and the number of IL-4-producing splenocytes were reduced by in vivo administration of andrographolide. Reduced phosphorylation levels of ERK1/2 and AKT were observed in macrophages treated with andrographolide.

Conclusion:

Andrographolide can modulate the innate and adaptive immune responses by regulating macrophage phenotypic polarization and Ag-specific antibody production. MAPK and PI3K signaling pathways may participate in the mechanisms of andrographolide regulating macrophage activation and polarization.     

Baicalin ameliorates experimental inflammatory bowel disease through polarization of macrophages to an M2 phenotype

Inflammatory bowel diseases (IBDs) are chronic inflammatory disorders of the intestinal tract. Baicalin, originally isolated from the root of the Chinese herb Huangqin (Scutellaria baicalensis Georgi) and its main active ingredient, has a protective effect against inflammatory responses in several diseases. The present study investigated the effects of baicalin on macrophage polarization and its therapeutic role in IBD. Murine peritoneal macrophages and mice with colitis were treated with baicalin. Macrophage subset distribution, M1 and M2 macrophage-associated mRNA expression, and interferon regulatory factor 4 and 5 (IRF4 and IRF5) expression were analyzed. siRNA transfection into mouse peritoneal macrophages was utilized to suppress IRF4. Fluorescence-activated cell sorting, western blot, and real-time PCR analyses were performed. Baicalin (50 μM) limited lipopolysaccharide (LPS)-induced M1 macrophage polarization; decreased LPS-induced tumor necrosis factor α, interleukin (IL)-23, and IRF5 expression; and increased IL-10, arginase-1 (Arg-1), and IRF4 expression. siRNA-mediated IRF4 silencing significantly impaired baicalin activity. Furthermore, pretreatment with baicalin (100 mg/kg) in mice with dextran sodium sulfate (DSS)-induced colitis ameliorated the severity of colitis and significantly decreased the disease activity index (baicalin group, 3.33 ± 0.52 vs. DSS group, 5.67 ± 1.03). Baicalin (100 mg/kg) also repressed IRF5 protein expression and promoted IRF4 protein expression in the lamina propria mononuclear cells, and induced macrophage polarization to the M2 phenotype. In summary, our results showed that baicalin upregulates IRF4 protein expression and reverses LPS-induced macrophage subset redistribution. Thus, baicalin alleviates DSS-induced colitis by modulating macrophage polarization to the M2 phenotype.