简介:摘要目的观察脱细胞真皮基质(ADM)对巨噬细胞特征性标志物表达的影响。方法实验分组:A组,巨噬细胞组;B组,ADM(5 μg/μl)与巨噬细胞共培养组;C组,脂多糖(LPS,100 ng/ml)及γ-干扰素(IFN-γ)(10 ng/ml)联合诱导巨噬细胞组;D组,白细胞介素-4(IL-4,10 ng/ml)诱导巨噬细胞组;E组,LPS(100 ng/ml)及IFN-γ(10 ng/ml)联合诱导巨噬细胞后再与ADM(5 μg/μl)共培养组。采用实时反转录-聚合酶链反应(RT-PCR)和蛋白质印迹法(Western blot)检测不同组巨噬细胞一氧化氮合成酶(iNOS)、分化抗原86(CD86)、甘露糖受体(CD206)和精氨酸酶-1(Arg-1) mRNA和蛋白的相对表达水平,组间比较采用t检验,多组间采用单因素方差分析。结果RT-PCR检测结果显示,M1型巨噬细胞标志物iNOS、CD86的表达在C组中最高(2.82±0.07、3.07±0.24,FiNOS=210.3,FCD86=85.6,P<0.01)。M2型巨噬细胞标志物CD206、Arg-1的表达在D组中最高(3.30±0.26、3.23±0.32,FCD206=115.4,FArg-1=71.2,P<0.01)。B组与A组比较,M1型和M2型巨噬细胞标志物的表达差异无统计学意义(t=1.706,P>0.05)。E组与C组比较,M1型巨噬细胞标志物iNOS、CD86的表达量下降,分别由C组的2.82±0.07、3.07±0.24下降到E组的2.21±0.10、1.96±0.04;而M2型巨噬细胞标志物CD206、Arg-1的表达量增高,分别由C组的1.01±0.16、0.97±0.16上升到E组的1.87±0.14、1.91±0.14;两组差异有统计学意义(tiNOS=8.523,tCD86=7.702,tCD206=7.028,tArg-1=7.904,P<0.05)。Western blot检测结果与RT-PCR的检测结果趋势一致。结论ADM有诱导巨噬细胞从M1型向M2型极化的作用。
简介:证明0是具有可选服务的M/M/1排队模型的主算子及其共轭算子的几何重数为1的特征值,由此推出该模型的时间依赖解强收敛于该模型的稳态解.
简介:AbstractBackground:Macrophages play an important role in renal ischemia reperfusion injury, but the functional changes of macrophages under hypoxia/reoxygenation and the related mechanism are unclear and need to be further clarified.Methods:The effects of hypoxia/reoxygenation on functional characteristics of RAW264.7 macrophages were analyzed through the protein expression detection of pro-inflammatory factors TNF-α and CD80, anti-inflammatory factors ARG-1 and CD206. The functional implications of C-X3-C motif chemokine receptor 1(CX3CR1) down-regulation in hypoxic macrophages were explored using small interfering RNA technology. Significance was assessed by the parametric t-test or nonparametric Mann-Whitney test for two group comparisons, and a one-way ANOVA or the Kruskal-Wallis test for multiple group comparisons.Results:Hypoxia/reoxygenation significantly increased the protein expression of M1-related pro-inflammatory factors TNF-α, CD80 and chemokine C-X3-C motif chemokine ligand 1 (CX3CL1)/CX3CR1 and inhibited the protein expression of M2-related anti-inflammatory factors ARG-1 and CD206 in a time-dependent manner in RAW264.7 cells. However, the silencing of CX3CR1 in RAW264.7 cells using specific CX3CR1-siRNA, significantly attenuated the increase in protein expression of TNF-α (P < 0.05) and CD80 (P < 0.01) and the inhibition of ARG-1 (P < 0.01) and CD206 (P < 0.01) induced by hypoxia/reoxygenation. In addition, we also found that hypoxia/reoxygenation could significantly enhance the migration (2.2-fold, P < 0.01) and adhesion capacity (1.5-fold, P < 0.01) of RAW264.7 macrophages compared with the control group, and CX3CR1-siRNA had an inhibitory role (40% and 20% reduction, respectively). For elucidating the mechanism, we showed that the phosphorylation levels of ERK (P < 0.01) and the p65 subunit of NF-κB (P < 0.01) of the RAW264.7 cells in the hypoxic/reoxygenation group were significantly increased, which could be attenuated by down-regulation of CX3CR1 expression (P < 0.01, both). ERK inhibitors also significantly blocked the effects of hypoxic/reoxygenation on the protein expression of M1-related pro-inflammatory factors TNF-α, CD80 and M2-related anti-inflammatory factors ARG-1 and CD206. Moreover, we found that conditioned medium from polarized M1 macrophages induced by hypoxia/reoxygenation, notably increased the degree of apoptosis of hypoxia/reoxygenation-induced TCMK-1 cells, and promoted the protein expression of pro-apoptotic proteins bax (P < 0.01) and cleaved-caspase 3 (P < 0.01) and inhibited the expression of anti-apoptotic protein bcl-2 (P < 0.01), but silencing CX3CR1 in macrophages had a protective role. Finally, we also found that the secretion of soluble CX3CL1 in RAW264.7 macrophages under hypoxia/reoxygenation was significantly increased.Conclusions:The findings suggest that hypoxia/reoxygenation could promote M1 polarization, cell migration, and adhesion of macrophages, and that polarized macrophages induce further apoptosis of hypoxic renal tubular epithelial cells by regulating of CX3CL1/CX3CR1 signaling pathway.