Effects ofin vivo taurine depletion on induced- chemiluminescence production in macrophages isolated from rat lungs

Summary Alveolar macrophages isolated by pulmonary lavage from partially taurine-depleted ratsdemonstrated increased (2–2.6 fold) chemiluminescence due to the extracellular reaction between exogenous zymosan and various reactive forms of oxygen compared to macrophages isolated from control animals. Partial taurine depletion was achieved by adding 3% ß-alanine to the drinking water of the rats for 5 weeks prior to harvesting the macrophages. Superoxide dismutase activity was not increased in the lung tissue of the taurine-depleted rats. These data suggest that taurine has antioxidant properties and that taurine depletion is potentially deleterious to alveolar macrophages and pulmonary tissue.     

巨噬细胞吞噬过程中膜磷脂流动性和受体流动性的关系

本文用ＦＲＡＰ（ｆｌｕｏｒｅｓｃｅｎｃｅｒｅｃｏｖｅｒｙａｆｔｅｒｐｈｏｔｏｂｌｅａｃｈｉｎｇ）技术,测量了静息状态和刀豆素Ａ刺激不同时间后巨噬细胞膜磷脂、ＣｏｎＡ受体扩散系数和荧光恢复率的变化。结果显示ＣｏｎＡ刺激后膜磷脂和ＣｏｎＡ受体的扩散系数和荧光恢复率均较静息状态的巨噬细胞明显降低,磷脂流动性的变化与ＣｏｎＡ受体流动性的变化呈正相关。提示受体介导内吞导致的膜磷脂流动性的降低,可能是由于配体与细胞膜上受体结合形成配体－受体复合体,增加了受体的负荷,使受体的流动性降低,进而使膜磷脂的流动性降低。巨噬细胞内吞过程中膜磷脂和ＣｏｎＡ受体流动性的降低,可能还与ＣｏｎＡ刺激后巨噬细胞胞浆ｐＨ值有关。     

ABC法在膜受体流动性测量中的应用

本文首次把ABC法应用于受体流动性测量中的膜表面受体荧光标记,利用FRAP(Fluorescence Recovery After Photobleaching)技术实现了细胞内吞过程中膜受体流动性变化的测量.实验用Con A—Biotin和Avidin—FITC(ABC法)标记巨噬细胞ConA受体,测量ConA刺激不同时间细胞膜表面受体的荧光强度、扩散系数和荧光恢复率的变化.结果显示ABC标记法适合于测量细胞内吞过程中膜表面受体的流动性变化,且具有较高的灵敏度高;巨噬细胞受ConA刺激后,膜表面ConA受体的扩散系数和荧光恢复率较静息状态时明显降低.     

雪莲对正常及辐射损伤小鼠巨噬细胞功能的影响

本文研究了５０％雪莲水煎剂对正常及５ＧＹ６０Ｃｏ一次性全身照射ＢＡＬＢ／Ｃ小鼠巨噬细胞功能的影响,结果表明：口服５０％雪莲水煎剂能增强巨噬细胞吞噬鸡血球及分泌肿瘤坏死因子（ＴＮＦ）的能力,与相应对照组比较具有显著性差异,提示中药雪莲具有扶正固本提高机体防御机能及促进辐射损伤修复的作用。为该药的临床应用提供了科学依据。     

脂多糖增加小鼠巨噬细胞多磷酸肌醇脂代谢转换

多磷酸肌醇脂（这里指ＰＩＰ和ＰＩＰ２）的代谢在细胞信息传递和膜运转中起着重要的作用．脂多糖（ｌｉｐｏｐｏｌｙｓａｃｃｈａｒｉｄｅ,ＬＰＳ）于激活小鼠腹腔巨噬细胞（Ｍφ）初期（０．５～１ｈ）和后期（１６ｈ）明显增加来自［γ－３２Ｐ］ＡＴＰ的３２Ｐ参入Ｍφ的ＰＩＰ和ＰＩＰ２,３２Ｐ参入ＰＩＰ２的显著性大于ＰＩＰ．ＬＰＳ的这种作用在其激活Ｍφ的初期不受酪氨酸蛋白激酶抑制剂ｇｅｎｉｓｔｅｉｎ、蛋白激酶Ａ激动剂（ｆｏｒｓｋｏｌｉｎ）及百日咳毒素的影响;但佛波酯（ＰＭＡ）长时间预处理的Ｍφ（其ＰＫＣ活性被耗竭）再受ＬＰＳ刺激,［３２Ｐ］ＰＩＰ２水平较ＬＰＳ刺激未受ＰＭＡ预处理的Ｍφ明显降低．结果表明,ＬＰＳ于激活Ｍφ的初期和后期更显著增加ＰＩ４Ｐ－５激酶的活性,导致ＰＩＰ２合成增加,ＰＩＰ２合成的增加可能与Ｍφ激活时不同时期所表达的功能相关．     

巨噬细胞产生NO.和O_2~-自由基的分子机理

建立了用顺磁共振（ＥＳＲ）和化学发光技术测定巨噬细胞产生ＮＯ和氧自由基的方法．捕捉到了巨噬细胞受佛波酯刺激产生的ＮＯ．和Ｏ－２自由基．测定了在不同浓度Ｌ－精氨酸存在时佛波酯刺激后巨噬细胞产生的ＮＯ自由基．研究了巨噬细胞产生的ＮＯ和氧自由基的分子机理．结果表明巨噬细胞不仅产生氧自由基而且产生ＮＯ自由基．ＮＡＤＰＨ氧化酶产生氧自由基的部位位于巨噬细胞膜的外侧．ＮＯ合成酶活化产生ＮＯ自由基比ＮＡＤＰＨ氧化酶活化产生氧自由基晚几分钟．     

Antimicrobial peptide scolopendrasin VII,derived from the centipede Scolopendra subspinipes mutilans,stimulates macrophage chemotaxis via formyl peptide receptor 1

In this study, we report that one of the antimicrobial peptides scolopendrasin VII, derived from Scolopendra subspinipes mutilans, stimulates actin polymerization and the subsequent chemotactic migration of macrophages through the activation of ERK and protein kinase B (Akt) activity. The scolopendrasin VII-induced chemotactic migration of macrophages is inhibited by the formyl peptide receptor 1 (FPR1) antagonist cyclosporine H. We also found that scolopendrasin VII stimulate the chemotactic migration of FPR1-transfected RBL-2H3 cells, but not that of vector-transfected cells; moreover, scolopendrasin VII directly binds to FPR1. Our findings therefore suggest that the antimicrobial peptide scolopendrasin VII, derived from Scolopendra subspinipes mutilans, stimulates macrophages, resulting in chemotactic migration via FPR1 signaling, and the peptide can be useful in the study of FPR1-related biological responses. [BMB Reports 2015; 48(8): 479-484]     

Oxidized LDL induces phosphorylation of non-muscle myosin IIA heavy chain in macrophages

Oxidized LDL (oxLDL) performs critical roles in atherosclerosis by inducing macrophage foam cell formation and promoting inflammation. There have been reports showing that oxLDL modulates macrophage cytoskeletal functions for oxLDL uptake and trapping, however, the precise mechanism has not been clearly elucidated. Our study examined the effect of oxLDL on non-muscle myosin heavy chain IIA (MHC-IIA) in macrophages. We demonstrated that oxLDL induces phosphorylation of MHC-IIA (Ser1917) in peritoneal macrophages from wild-type mice and THP-1, a human monocytic cell line, but not in macrophages deficient for CD36, a scavenger receptor for oxLDL. Protein kinase C (PKC) inhibitor-treated macrophages did not undergo the oxLDL-induced MHC-IIA phosphorylation. Our immunoprecipitation revealed that oxLDL increased physical association between PKC and MHC-IIA, supporting the role of PKC in this process. We conclude that oxLDL via CD36 induces PKC-mediated MHC-IIA (Ser1917) phosphorylation and this may affect oxLDL-induced functions of macrophages involved in atherosclerosis. [BMB Reports 2015; 48(1): 48-53]     

Micro-RNAs and macrophage diversity in atherosclerosis: New players,new challenges…new opportunities for therapeutic intervention?

Efforts in experimental therapeutics of atherosclerosis are mostly focused on identifying candidate targets that can be exploited in developing new strategies to reduce plaque progression, induce its regression and/or improve stability of advanced lesions. Plaque macrophages are central players in all these processes, and consequently a significant amount of research is devoted to understanding mechanisms that regulate, for instance, macrophage apoptosis, necrosis or migration. Macrophage diversity is a key feature of the macrophage population in the plaque and can impact many aspects of lesion development. Thus, searching for molecular entities that contribute to atherorelevant functions of a specific macrophage type but not others may lead to identification of targets that can be exploited in phenotype selective modulation of the lesional macrophage. This however, remains an unmet goal. In recent years several studies have revealed critical functions of micro-RNAs (miRs) in mechanisms of macrophage polarization, and a number of miRs have emerged as being specific of distinctive macrophage subsets. Not only can these miRs represent the first step towards recognition of phenotype specific targets, but they may also pave the way to reveal novel atherorelevant pathways within macrophage subsets. This article discusses some of these recent findings, speculates on their potential relevance to atherosclerosis and elaborates on the prospective use of miRs to affect the function of plaque macrophages in a phenotype selective manner.     

Influence of olive-derived hydroxytyrosol on the toll-like receptor 4-dependent inflammatory response of mouse peritoneal macrophages

Macrophages play important roles in the host innate immune response and are involved in the onset of diseases caused by inflammation. Toll-like receptor 4 (TLR4)-mediated inflammatory responses of macrophages may be associated with diseases such as diabetes and diseases of the cardiovascular system. Hydroxytyrosol (HT) exerts strong antioxidant and anti-inflammatory effects and may be applied in the treatment of inflammatory diseases. In the present study conducted in vitro, we investigated the effects of the TLR4-dependent anti-inflammatory effect of HT on peritoneal macrophage of BALB/c mice. We show here that the elevated levels of iNOS gene expression and nitric oxide production induced by lipopolysaccharide (LPS) (0.25 μg/ml) were suppressed by HT (12.5 μg/ml). LPS-dependent NF-κB gene expression and phosphorylation of NF-κB were not affected by HT under these conditions. In contrast, the expression of TNF-α was significantly increased in the presence of LPS and HT. These results suggest that HT suppressed nitric oxide production by decreasing iNOS gene expression through a mechanism independent of the NF-κB signaling pathway. These novel findings suggest that the modulation by HT of the expression of genes involved in inflammation may involve multiple mechanisms.