高迁移率族蛋白B1对磷酸钙诱导巨噬细胞释放炎症因子的协同作用

背景：研究表明,巨噬细胞及其炎症反应参与了肾结石的发生发展。前期实验发现结石晶体可刺激巨噬细胞释放高迁移率族蛋白B1。 目的：观察高迁移率族蛋白B1对磷酸钙诱导巨噬细胞释放白细胞介素1β、白细胞介素6、肿瘤坏死因子α、单核细胞趋化因子1的协同作用。 方法：实验分两部分：①将成功诱导为巨噬细胞的U937细胞分为空白组、100 mg/L磷酸钙组、100 μg/L高迁移率族蛋白B1组、100 mg/L磷酸钙+100 μg/L高迁移率族蛋白B1组,干预1,2,4 h后收集细胞上清液。②将已成功诱导为巨噬细胞的U937细胞分为100 mg/L磷酸钙组、磷酸钙+10 μg/L高迁移率族蛋白B1组、磷酸钙+50 μg/L高迁移率族蛋白B1组、磷酸钙+100 μg/L高迁移率族蛋白B1组,干预4 h后收集细胞上清液。Elisa法检测白细胞介素1β、白细胞介素6、肿瘤坏死因子α、单核细胞趋化因子1水平。 结果与结论：ELISA结果显示,磷酸钙组,100 μg/L高迁移率族蛋白B1组上清液白细胞介素1β、白细胞介素6、肿瘤坏死因子α、单核细胞趋化因子1质量浓度均高于空白组,磷酸钙+100 μg/L高迁移率族蛋白B1组上清液上述因子质量浓度均显著高于其他3组(P < 0.05),且呈时间依赖性。不同质量浓度高迁移率族蛋白B1+磷酸钙组细胞上清液白细胞介素1β、白细胞介素6、肿瘤坏死因子α、单核细胞趋化因子1水平均显著高于磷酸钙组(P < 0.05),且呈浓度依赖性。结果表明,磷酸钙及高迁移率族蛋白B1均可诱导巨噬细胞释放白细胞介素1β、白细胞介素6、肿瘤坏死因子α、单核细胞趋化因子1;高迁移率族蛋白B1可协同磷酸钙诱导巨噬细胞释放白细胞介素1β、白细胞介素6、肿瘤坏死因子α、单核细胞趋化因子1。 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程全文链接：     

微弧氧化镁合金对巨噬细胞肿瘤坏死因子和白细胞介素6的影响

背景：微弧氧化处理可提高镁合金的抗腐蚀性能,延缓其降解速率。 目的：观察微弧氧化处理镁合金对小鼠巨噬细胞肿瘤坏死因子α和白细胞介素6的影响。 方法：在小鼠RAW264.7细胞中分别加入镁合金浸提液(对照组)、微弧氧化处理镁合金浸提液(实验组)及RPMI-1640(空白对照组),1 h后加入脂多糖,作用24 h后,收集细胞上清液,检测肿瘤坏死因子α和白细胞介素6水平,MTT法测定脂多糖刺激前后的RAW264.7细胞活性。 结果与结论：①脂多糖刺激前的RAW264.7细胞活性：对照组>实验组>空白对照组(P均< 0.05)。②脂多糖刺激后的RAW264.7细胞活性：实验组与对照组高于刺激前,但差异无显著性意义;空白对照组明显高于刺激前(P < 0.01)。3组间RAW264.7细胞活性差异无显著性意义(P > 0.05)。③脂多糖刺激后RAW264.7细胞白细胞介素6与肿瘤坏死因子α的表达量：对照组白细胞介素6表达量明显高于实验组和空白对照组(P < 0.05);3组肿瘤坏死因子α表达量两两之间比较差异无显著性意义(P > 0.05)。表明微弧氧化处理镁合金对小鼠巨噬细胞活性无明显影响,同时降低了炎性反应。     

淫羊藿苷抑制钛颗粒诱导的炎症反应

背景：体外实验表明,淫羊藿苷可抑制脂多糖诱导的急性肺炎,其抗炎作用在磨损颗粒存在的条件下是否依然有效？目的：通过体内外实验相结合的方法探讨淫羊藿苷对磨损颗粒诱导炎症反应的调控作用。方法：①体内实验：将80只雄性C57BL/6小鼠随机分为4组,钛组和钛+淫羊藿苷组采用钛诱导小鼠颅骨无菌炎症模型,对照组、淫羊藿苷组也进行相同手术过程,但不植入钛,淫羊藿苷组、钛+淫羊藿苷组建模当天灌胃给予淫羊藿苷200 mg/(kg·d),对照组、钛组灌胃给予等量的安慰剂,2周后酶联免疫吸附实验、定量RT-PCR检测肿瘤坏死因子α,白细胞介素1β蛋白或mRNA的表达量。②体外实验：将小鼠单核/巨噬细胞RAW264.7分别与核因子кB受体配体、核因子кB受体配体+淫羊藿苷、核因子кB受体配体+钛颗粒及核因子кB受体配体+钛颗粒+淫羊藿苷共培养72 h,ELISA检测培养基上清中肿瘤坏死因子α,白细胞介素1β水平,RT-PCR分析肿瘤坏死因子α,白细胞介素1β基因mRNA表达。结果与结论：①体内实验：在钛颗粒存在的条件下,口服淫羊藿苷可明显减少颗粒诱导的炎症细胞浸润,使炎性增厚的骨膜变薄,抑制颅骨标本中肿瘤坏死因子α,白细胞介素1β的表达。②体外实验：经钛颗粒刺激后,细胞培养基中肿瘤坏死因子α,白细胞介素1β质量浓度显著增加,细胞中相应mRNA表达量上调,而经淫羊藿苷干预后这两种炎性因子在蛋白和基因水平的表达量显著下调。结果表明淫羊藿苷在体内外均可显著抑制钛颗粒诱导的炎症反应。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程全文链接：     

红霉素、阿仑膦酸钠抑制磨损颗粒对小鼠巨噬细胞分泌白细胞介素1，6及肿瘤坏死因子α的影响

背景：阿仑膦酸钠的抗骨吸收作用是通过其对破骨细胞的抑制作用完成的,近年亦有报道证实红霉素有直接抑制破骨细胞的作用。 目的：观察阿仑膦酸钠和红霉素抑制钛颗粒刺激巨噬细胞分泌肿瘤坏死因子α、白细胞介素1,6的作用。 方法：分离、培养小鼠腹腔巨噬细胞,14 h后分为红霉素组及阿仑膦酸钠组,每组分为6个亚组。红霉素组：A组：仅为巨噬细胞;B组：巨噬细胞+钛颗粒;C组：巨噬细胞+钛颗粒+红霉素1 μg/L;D组：巨噬细胞+钛颗粒+红霉素10 μg/L;E组：巨噬细胞+钛颗粒+红霉素100 μg/L;F组：巨噬细胞+钛颗粒+红霉素1 000 μg/L。阿仑膦酸钠组分组及剂量同红霉素组。培养24 h后,用酶联免疫法检测细胞培养上清液中白细胞介素1,6及肿瘤坏死因子α的质量浓度。 结果与结论：B组白细胞介素1,6及肿瘤坏死因子α的质量浓度明显高于其他组(P < 0.05),F组白细胞介素1,6及肿瘤坏死因子α的质量浓度明显低于C组(P < 0.05)。同剂量阿仑膦酸钠和红霉素组间差异无显著性意义(P > 0.05)。提示钛颗粒可以刺激巨噬细胞分泌大量的白细胞介素1,6及肿瘤坏死因子α,红霉素、阿仑膦酸钠能够呈剂量依赖型地有效抑制钛颗粒诱导的巨噬细胞分泌白细胞介素1,6及肿瘤坏死因子α。     

脂氧素受体激动剂对巨细胞病毒感染巨噬细胞的免疫负调节

背景：脂氧素可以抑制炎症细胞、内皮细胞、小鼠脾脏树突状细胞等合成细胞因子,还可以抑制炎性细胞因子对细胞的生物效应。 目的：分析脂氧素受体激动剂BML-111对人巨细胞病毒感染THP-1源巨噬细胞的免疫调节作用。 方法：用人巨细胞病毒 AD169毒株感染THP-1源巨噬细胞(MOI=0.5),细胞培养后设立对照组、人巨细胞病毒感染组及人巨细胞病毒+BML-111组。在感染后0,1,2,4,12,24,48,72 h收集各组细胞培养上清液,以ELISA检测各组细胞因子的表达水平; RT-PCR检测各指标mRNA的表达强度;Western blot检测感染4 h的细胞核内p65亚基蛋白表达。 结果与结论：与对照组相比,其他两组各细胞因子蛋白及mRNA表达明显升高(P < 0.05)。与人巨细胞病毒感染组相比,人巨细胞病毒+BML-111组白细胞介素1β和肿瘤坏死因子α显著降低,转化生长因子β显著升高(P < 0.05),白细胞介素10差异无显著性意义(P > 0.05);人巨细胞病毒+BML-111组各细胞因子mRNA均明显降低(P < 0.05)。与对照组相比,其他两组细胞核内NF-κB p65亚基蛋白浓度明显升高(P < 0.05);人巨细胞病毒+BML-111组显著低于人巨细胞病毒感染组(P < 0.05)。说明BML-111可能通过抑制NF-κB的p65亚基核转位,减少白细胞介素1β、肿瘤坏死因子α的表达,促进转化生长因子β的表达,从而对人巨细胞病毒感染的THP-1源巨噬细胞发挥其免疫负调节作用。     

同型半胱氨酸对培养的人单核细胞株THP-1 表达巨噬细胞炎性蛋白-1α的影响

目的: 探讨同型半胱氨酸对人单核细胞株THP-1细胞表达巨噬细胞炎性蛋白-1α mRNA和蛋白的影响。 方法:在体外培养的THP-1单核细胞培养基中加入终浓度为0.05 mmol/L、0.1 mmol/L和0.2 mmol/L的同型半胱氨酸,孵育8 h;或加入终浓度0.1 mmol/L的同型半胱氨酸,分别孵育4、8、16 h。用逆转录聚合酶链反应检测THP-1单核细胞巨噬细胞炎性蛋白-1α mRNA,并测序;用免疫细胞化学法检测巨噬细胞炎性蛋白-1α蛋白的表达。结果:对照组THP-1单核细胞表达较低水平的巨噬细胞炎性蛋白-1α mRNA,加同型半胱氨酸后巨噬细胞炎性蛋白-1α mRNA表达随浓度增加而增强;在浓度为0.1 mmol/L时,巨噬细胞炎性蛋白-1α mRNA表达于4 h开始升高,8 h后逐渐降低。反应产物真实性经测序反应证实。免疫细胞化学图像分析结果显示,各组细胞平均吸光度值随浓度和时间递增而增加(P＜0.01)。结论:同型半胱氨酸能诱导THP-1单核细胞表达巨噬细胞炎性蛋白-1α mRNA和蛋白。     

白藜芦醇调控体外培养人骨关节炎滑膜细胞白细胞介素18的表达

背景：白藜芦醇可在体外抑制软骨细胞的凋亡。 目的：观察白藜芦醇对体外培养人骨关节炎滑膜细胞中白细胞介素18、白细胞介素1β和肿瘤坏死因子α表达的影响。 方法：对兔以白藜芦醇临床等效剂量灌胃后,制备含10%,20%,40%白藜芦醇含药血清,与人骨关节炎滑膜细胞共培养,以正常兔血清培养细胞为对照。 结果与结论：ELISA检测及免疫细胞化学检测结果显示,不同浓度白藜芦醇含药血清组体外培养滑膜细胞白细胞介素18、白细胞介素1β、肿瘤坏死因子α分泌量较正常兔血清组明显降低(P < 0.01),并随白藜芦醇浓度的增加,白细胞介素18、白细胞介素1β、肿瘤坏死因子α分泌量逐渐降低(P < 0.01或P < 0.05)。白细胞介素1β、肿瘤坏死因子α水平依次与白细胞介素18水平呈正相关。表明白藜芦醇能够显著下调白细胞介素18、白细胞介素1β、肿瘤坏死因子α在骨关节炎滑膜细胞中的表达,减轻滑膜炎症反应。     

川芎嗪可影响肿瘤坏死因子α刺激肝星状细胞结缔组织生长因子、核因子κB及相关基因产物的表达

背景：川芎嗪延缓肝纤维化形成的机制尚不清楚。 目的：观察川芎嗪对肿瘤坏死因子α刺激的肝星状细胞增殖及结缔组织生长因子、核因子κB及其相关基因产物白细胞介素6表达的影响。 方法：体外培养HSC-T6细胞株,取对数生长期的细胞用于实验。实验分为4组：对照组仅加入细胞;TNF-α组加入10 μg/L TNF-α;川芎嗪干预组先加入终浓度为10 μg/L的TNF-α作用30 min后,分别加入川芎嗪50,100,200,400,600, 1 000 mg/L;PDTC组先加入终浓度为10 μg/L的TNF-α作用30 min后,再加入终浓度18 μmol/L的核因子κB阻断剂PDTC。 结果与结论：MTT结果显示100,200,400,600,1 000 mg/L的川芎嗪均能抑制HSC-T6增殖,且呈剂量依赖性。免疫细胞化学染色及Western blot检测发现10 μg/L的肿瘤坏死因子α刺激后,HSC-T6细胞结缔组织生长因子、核因子κB及白细胞介素6的表达明显增多(P < 0.01或P < 0.05),200,400,600 mg/L的川芎嗪及18 μmol/L的PDTC均可明显降低肿瘤坏死因子α刺激后HSC-T6细胞结缔组织生长因子、核因子κB及白细胞介素6的表达(P < 0.01),且随着川芎嗪质量浓度的增加,抑制作用增强,PDTC的抑制作用最明显。相关性分析结果显示HSC-T6细胞结缔组织生长因子和核因子κB的表达呈正相关(r=0.980,P < 0.01)。说明川芎嗪可以抑制肝星状细胞结缔组织生长因子、核因子κB及白细胞介素6的表达,抑制肝星状细胞的增殖。     

微小RNA-155在小鼠骨髓来源M1和M2巨噬细胞中表达的差异**

背景：目前对微小RNA-155在巨噬细胞中的表达和功能的研究还集中在总体单核巨噬细胞水平。 目的：了解小鼠骨髓来源M1和M2巨噬细胞中微小RNA-155表达的差异。 方法：用100 U/mL干扰素γ和5 μg/L脂多糖诱导骨髓细胞来源的巨噬细胞向M1分化,用10 μg/L白细胞介素4诱导出M2巨噬细胞。 结果与结论：流式细胞检测显示实验诱导的M1和M2巨噬细胞纯度分别达91%和95%。RT-PCR检测显示诱导型一氧化氮合酶mRNA在M1巨噬细胞中高表达,在M2中则基本不表达;而Ⅰ型精氨酸酶、发现于炎症区域1 mRNA在M2中高表达,在M1中则表达较低;炎症因子肿瘤坏死因子α mRNA在M1中的表达明显高于M2,相反白细胞介素10 mRNA在M2中的表达高于M1(P < 0.05)。实时荧光定量PCR检测显示M1巨噬细胞中微小RNA-155的表达量明显高于M2(P < 0.05)。提示微小RNA-155可作为鉴别M1,M2巨噬细胞的标志。     

早期应用生长反应因子1小干扰RNA可抑制烟草烟雾刺激大鼠主动脉平滑肌细胞白细胞介素1β mRNA的表达

背景：研究表明,在动脉粥样硬化的血管壁细胞中白细胞介素1β表达水平升高。 目的：观察早期生长反应因子1的小干扰RNA对烟草烟雾提取物刺激大鼠主动脉平滑肌细胞中白细胞介素1β mRNA表达的影响。 方法：体外培养大鼠主动脉平滑肌细胞,用不同体积分数(0%,5%,10%,20%和40%)烟草烟雾提取物刺激细胞,筛选最佳体积分数烟草烟雾提取物干预细胞0,8,16和24 h,以确定最佳干预时间,最后用生长反应因子1小干扰RNA以沉默细胞中生长反应因子1的表达。  结果与结论：RT-PCR结果显示,烟草烟雾提取物可诱导大鼠主动脉平滑肌细胞白细胞介素1β mRNA的表达,且有时间和浓度依赖性,烟草烟雾提取物最佳干预时间为8 h,最佳干预体积分数为10%。将生长反应因子1小干扰RNA转染10%烟草烟雾提取物刺激的细胞后8 h,白细胞介素1β mRNA表达明显减少(P < 0.05)。证实早期应用生长反应因子1小干扰RNA可以抑制烟草烟雾提取物诱导的大鼠主动脉平滑肌细胞中白细胞介素1β mRNA的表达。     

Recently infiltrating MAC387(+) monocytes/macrophages a third macrophage population involved in SIV and HIV encephalitic lesion formation

Monocytes/macrophages are critical components of HIV and SIV encephalitic lesions. We used in vivo BrdU labeling and markers specific to stages of macrophage differentiation or inflammation to define macrophage heterogeneity and to better define the role of macrophage populations in lesion formation and productive infection. Lesions were heterogeneously composed of resident macrophages (CD68(+)HAM56(+)), perivascular macrophages (CD163(+) CD68(+)MAC387(-)), and recently infiltrated MAC387(+) CD68(-)CD163(-) monocytes/macrophages. At 24 and 48 hours after BrdU inoculation, 30% of MAC387(+) monocytes/macrophages were BrdU(+), consistent with their being recently infiltrated. In perivascular cuffs with low-level SIV replication, MAC387(+) monocytes/macrophages outnumbered CD68(+) macrophages. Conversely, lesions with numerous SIV-p28(+) macrophages and multinucleated giant cells had fewer MAC387(+) monocytes/macrophages. The MAC387(+) cells were not productively infected nor did they express detectable CCR2, unlike perivascular macrophages. Overall, we found that the proportion of MAC387(+) cells tends to be higher than the proportion of CD68(+) macrophages in the brain of animals with mild encephalitis; the ratio was reversed with more severe encephalitis. These results suggest that development of SIV and HIV encephalitis is an active and ongoing process that involves the recruitment and accumulation of: i) nonproductively infected MAC387(+) monocytes/macrophages that are present with inflammation (potentially M1-like macrophages), ii) CD163(+) perivascular macrophages (consistent with M2-like macrophages), and iii) CD68(+) or HAM56(+) resident macrophages. The latter two populations are cellular reservoirs for productive infection.     

De Novo renal expression of macrophage migration inhibitory factor during the development of rat crescentic glomerulonephritis.

Macrophage migration inhibitory factor (MIF), a key mediator of the delayed-type hypersensitivity response, was originally thought to be produced by activated T cells. However, recent studies have found that MIF is produced in many cell types including monocytes/macrophages and anterior pituitary cells. The current study has examined MIF expression in normal and diseased kidney using in situ hybridization, immunohistochemistry, and Northern blotting. MIF mRNA and protein are constitutively expressed in normal kidney, being largely restricted to tubular epithelial cells and some glomerular visceral and parietal epithelial cells. During the development of rat anti-glomerular basement membrane glomerulonephritis, a model of macrophage-mediated renal injury, there was marked de novo expression of MIF by intrinsic kidney cells including endothelium and glomerular and tubular epithelial cells. Up-regulation of MIF expression correlated with macrophage accumulation within the glomerulus (P < 0.001) and tubulointerstitium (P < 0.001). Of significance, the accumulation of macrophages was exclusively localized to areas of strong MIF expression, contributing to focal glomerular and tubulointerstitial lesion formation. In addition, up-regulation of MIF expression by parietal epithelial cells was associated with macrophage accumulation within Bowman's space and crescent formation. Combined in situ hybridization and immunostaining also demonstrated MIF expression by macrophages, T cells, and fibroblast-like cells within renal lesions. In conclusion, these data provide the first demonstration that renal epithelial cells are a major source of MIF in both normal and diseased kidney. Furthermore, the up-regulation of MIF expression may play an important role in macrophage accumulation and progressive renal injury in rat crescentic glomerulonephritis.     

Monoclonal antibody EBM/11: high cellular specificity for human macrophages.

A monoclonal antibody, EBM/11, was raised against isolated human lung macrophages. Immunohistochemically this antibody reacted with freshly isolated lung macrophages and blood monocytes, mononuclear cells (presumptive macrophages) in sections of lung, skin, stomach, small and large bowel, pancreas, spleen, tonsil, placenta, liver, gall bladder, heart, thyroid, pituitary, brain, and peritubular and mesangial cell in kidney. Microglial cells and osteoclasts also labelled with EBM/11. The antibody reacted with cytoplasmic structures rather than with cell membranes. The epitope recognised by EBM/11 was present on four polypeptides (of 120, 70, 64 and 22 kilodaltons). It did not react with any other cell type in the tissues screened except the epithelium of renal proximal tubules. This antibody may be useful in identifying and elucidating the function of macrophages in pathological processes.     

非免疫因素肾病的免疫发病机制

非免疫因素性肾病是指由许多非免疫性因素导致的肾脏损害包括急慢性肾脏局部缺血、蛋白负荷过多、高脂血症、肾大部切除、膀胱输尿管返流、尿路梗阻、多囊肾、糖尿病、年龄老年化、肾盂肾炎、高血压、肾毒性物质（药物和毒物）、血流动力学改变、代谢因素等，此类肾病在临床上越来越常见，是发展成肾间质纤维化的主要因素，其病理变化主要表现为淋巴细胞、巨噬细胞的浸润。发病机制包括RAS系统、ROS系统、免疫发病机制及肾微血管内皮细胞和肾小管上皮细胞损伤导致的免疫活性细胞的浸润及分泌的细胞因子的作用。对于非免疫肾病的治疗主要有：ACEI、ARBs、免疫抑制剂强的松、环磷酰胺、环孢霉素和霉芬酸酯等，研究的热点是共刺激分子。     

A Preserved Native Kidney Alters Acute Renal Allograft Rejection in the Rat

In this study the effect of a native recipient kidney on acute rat renal allograft rejection is analysed. The authors performed a sequential daily analysis of allograft morphology and infiltration by macrophages and T cells in the presence and the absence of a recipient kidney. Several differences among both experimental groups were observed. Infiltrating macrophages and T cells in the allograft interstitium were more numerous in the presence than in the absence of a recipient kidney. The ratio of macrophages to T cells was 2:1 in the presence and 1:1 in the absence of a recipient kidney. Interstitial allograft infiltration started 1 day earlier in the presence of a contralateral kidney than in its absence. Graft necrosis occurred on day 6 and was complete in the presence of a native kidney. After total nephrectomy a patchy pattern of necrotic and viable tubules was observed from day 5 until the death of the animal. The diameter of monocytes in graft vessels increased only moderately in the presence of a recipient kidney but duplicated in its absence. The authors propose that in experimental renal transplantation contralateral nephrectomy should be performed according to a standardized schedule.     

Macrophages and Dendritic Cells during the Early Stages of Antigen-Induced Arthritis in Rats: Immunohistochemical Analysis of Cryostat Sections of the Whole Knee Joint

The appearance of different macrophage subpopulations, Ia-positive antigen-presenting dendritic cells and of T and B lymphocytes was studied in early phases of antigen-induced arthritis in rat knee joints. Cryostat sections of whole knee joints were analysed with immunohistochemical techniques using monoclonal antibodies against rat macrophages, Ia-antigen, and lymphocyte subpopulations. The results showed that in the early phases of the development of arthritis, the synovium was already infiltrated by many monocytes, young macrophages, granulocytes, perivascular Ia-positive non-lymphoid cells, some mature tissue macrophages, and only few T lymphocytes. In later phases not only monocytes, young macrophages and Ia-positive cells became more prominent but also the more mature ED2 positive macrophages and the ED3 positive macrophages that are normally confined to lymphoid organs became increasingly important. The T-cell population increased to some extent in later phases of arthritis induction, possibly induced by clustering with the Ia-positive cells.     

Monocytes in the rat: Phenotype and function during acute allograft rejection

Summary: Cells of the monocyte/macrophage system originate from the bone marrow, reach the organs via the blood, immigrate through post-capillary venules and further differentiate into organ-specific tissue macrophages. In rats and other species, activated monocytes/macrophages aggravate autoimmune reactions, rejection of non-vascularized allografts and chronic allograft rejection. It is very likely that they also contribute to acute allograft destruction. So far it has been impossible to distinguish the function of monocytes from that of macrophages, because cell phenotypes and their alterations upon activation are ill-defined. We have thus begun to characterize the ex vivo phenotype and function of rat monocytes in the normal state and during renal allograft rejection. Monocytes are recovered from both the central and the marginal blood pool by perfusing either the recipient's circulation or the allograft vasculature. Rat monocytes have a unique surface phenotype. During allograft rejection or after infusion of interferon-γ they up-regulate class II MHC molecules, CD161 (NKR-P1A), CD62L and CD8, while CD4 and CD43 are down-modulated. Activated perfusate monocytes exert increased in vitro cytotoxicity against tumour targets, which differs from that of NK cells. We speculate that activated monocytes contribute to kidney allograft destruction by directly damaging endothelial cells or by promoting intravascular coagulation.     

Possible involvement of myofibroblasts in cellular recovery of uranyl acetate-induced acute renal failure in rats

Cellular recovery in acute renal failure is a form of wound healing. Fibroblast-like cells or myofibroblasts are involved in wound healing. We examined the serial changes in tubular damage and origin and kinetics of regenerating cells in uranyl acetate-induced acute renal failure, with a special emphasis on interstitial myofibroblasts. Acute renal failure was induced in rats by intravenous injection of uranyl acetate (5 mg/kg). All rats received bromodeoxyuridine intraperitoneally 1 hour before sacrifice. Serial changes in the distribution of tubular necrosis and bromodeoxyuridine-incorporated or vimentin-positive regenerating cells, and their spatial and temporal relation to alpha-smooth muscle actin-positive myofibroblasts as well as ED 1-positive monocytes/macrophages were examined. Necrotic tubules initially appeared around the corticomedullary junction after uranyl acetate injection, then spread both downstream and upstream of proximal tubules. Peritubular alpha-smooth muscle actin-positive myofibroblasts appeared and extended along the denuded tubular basement membrane, establishing network formation throughout the cortex and the outer stripe of outer medulla at days 4 to 5. Tubular regeneration originated in nonlethally injured cells in the distal end of S3 segments, which was confirmed by lectin and immunohistochemical staining using markers for tubular segment. Subsequently, upstream proliferation was noted along the tubular basement membrane firmly attached by myofibroblasts. During cellular recovery, no entry of myofibroblasts into the tubular lumen across the tubular basement membrane was noted and only a few myofibroblasts showed bromodeoxyuridine positivity. The fractional area of alpha-smooth muscle actin-positive interstitium reached a peak level at day 7 in the cortex and outer stripe of outer medulla, then gradually disappeared by day 15 and remained only around dilated tubules and in the expanded interstitium at day 21. ED 1-positive monocytes/macrophages were transiently infiltrated mainly into the region of injury. They did not show specific association with initially necrotic tubules, but some of them located in close proximity to regenerating tubules. Nonlethally injured cells at the distal end of proximal tubules are likely to be the main source of tubular regeneration, and the transient appearance of interstitial myofibroblasts attached to the tubular basement membrane immediately after tubular necrosis might play a role in promoting cellular recovery in possible association with monocytes/macrophages in uranyl acetate-induced acute renal failure.     

Production of monocyte chemoattractant protein-1 by malignant fibrous histiocytoma: relation to the origin of histiocyte-like cells.

Human malignant fibrous histiocytoma (MFH) comprise both fibroblast-like cells and histiocyte-like cells. We previously showed that the latter are not neoplastic cells, but are infiltrating macrophages. Since migration of blood monocytes into the tumor might be a response to a locally elaborated monocyte chemoattractant, we designed experiments to determine if the fibroblast-like tumor cells produced a chemoattractant for human monocytes. Malignant fibrous histiocytoma from three patients was put into culture. Cells of all three lines had a spindle shape, and showed no reactivity with antibodies against macrophages (MAC387), HLA-DR (LN3), or leukocyte common antigen. Immunohistochemically, they stained with antibody against human monocyte chemoattractant protein-1 (MCP-1). Culture supernatants of the three cell lines had chemotactic activity for monocytes. This activity was due to MCP-1, since it was absorbed by an anti-MCP-1 column. The production of MCP-1 by MFH tumor lines was confirmed by immunoprecipitation of metabolically labeled MCP-1. These results suggest that the histiocyte-like cells are the infiltrated macrophages that originate from blood monocytes attracted by tumor-derived MCP-1.     

Potential role for monocyte chemotactic protein-4 (MCP-4) in monocyte/macrophage recruitment in acute renal inflammation

The CC chemokine, monocyte chemoattractant protein-4 (MCP-4), is an important chemoattractant for monocytes and T cells. Recent data indicate a role in renal inflammation. This study has used in situ hybridization and immunohistochemical analysis of cryostat sections of biopsy material taken from patients with acute renal allograft rejection and vasculitic glomerulonephritis to demonstrate renal expression of MCP-4, both at message and protein level. MCP-4 was primarily expressed at peritubular, periglomerular, and perivascular sites, irrespective of the inflammatory condition, and was associated with infiltrating CD3-positive lymphocytes and CD68-positive monocyte/macrophages. In addition, proximal tubular epithelial cells grown in culture from cortical fragments of human kidney showed low levels of constitutive MCP-4 expression, detectable by western blotting; this expression of MCP-4 was up-regulated in response to the pro-inflammatory cytokines, tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma). CCR3-, CCR5- and CCR2-expressing leukocyte populations were identified at sites of MCP-4 expression. Double-staining techniques revealed that CC chemokine receptor-expressing cells were primarily CD68-positive. These studies suggest an important role for MCP-4 in the recruitment and retention of monocytes/macrophages in renal inflammation.