Bernatchez S F, Atkinson M R, Parks P J
Center for Interfacial Engineering, University of Minnesota, Minneapolis 55455, USA.
Biomaterials. 1997 Oct;18(20):1371-8. doi: 10.1016/s0142-9612(97)00072-0.
Macrophage activation is a major component of wound healing. It also determines the extent of inflammatory reactions and the response of the body to implanted materials. We have previously shown, using an in vitro model, that the extent of spreading of macrophages on different materials is a marker of activation, and that a soluble inducer has a dose-response effect on the secretion of cytokines in the culture medium. This work investigates the expression of three different cell surface markers [macrophages MAC-1, MAC-3 and intercellular adhesion molecule-1 (ICAM-1)] on macrophages in vitro using confocal microscopy and shows that ICAM-1 is also a marker of macrophage activation in this model. We observed increased amounts of ICAM-1 on activated macrophages compared to unactivated macrophages, whereas MAC-1 and MAC-3 were either expressed constitutively or demonstrated no quantitative change in expression after activation under the same experimental conditions. We also tested the expression of ICAM-1 with various concentrations of soluble inducers (lipopolysaccharide, 0.001, 0.01, 0.1, 1 and 10 micrograms ml-1. S-27609, 0.1, 0.25, 0.5, 1, 2 and 3 micrograms ml-1 and on a sheet of polylactic acid alone or in combination with soluble inducers. All doses of soluble inducers induced the expression of ICAM-1 on cells grown in glass chamber slides. The induction was not dose related but seemed to work rather in an on-off manner. There was no effect of material on ICAM-1 expression on the cell surface when no soluble inducer was added. This was similar to cytokine secretion, which was not induced by our material alone. When either lipopolysaccharide or S-27609 was used in combination with the material, there was an increase in the average measured intensity of ICAM-1. In this in vitro model, ICAM-1 staining as measured by confocal microscopy is a marker for macrophage activation. Our results suggest that the extent of macrophage activation as measured by ICAM-1 and by cytokine secretion is more sensitive to soluble inducers than to the action of the flat sheet of polylactic acid.
巨噬细胞激活是伤口愈合的一个主要组成部分。它还决定炎症反应的程度以及身体对植入材料的反应。我们之前使用体外模型表明，巨噬细胞在不同材料上的铺展程度是激活的一个标志，并且一种可溶性诱导剂对培养基中细胞因子的分泌具有剂量反应效应。这项工作使用共聚焦显微镜研究了三种不同细胞表面标志物[巨噬细胞MAC - 1、MAC - 3和细胞间黏附分子 - 1（ICAM - 1）]在体外巨噬细胞上的表达，并表明在该模型中ICAM - 1也是巨噬细胞激活的一个标志。我们观察到与未激活的巨噬细胞相比，激活的巨噬细胞上ICAM - 1的量增加，而在相同实验条件下，MAC - 1和MAC - 3要么组成性表达，要么激活后表达无定量变化。我们还测试了不同浓度的可溶性诱导剂（脂多糖，0.001、0.01、0.1、1和10微克/毫升。S - 27609，0.1、0.25、0.5、1、2和3微克/毫升）单独或与可溶性诱导剂联合作用于一片聚乳酸时ICAM - 1的表达。所有剂量的可溶性诱导剂都诱导生长在玻璃培养载玻片上的细胞表达ICAM - 1。这种诱导与剂量无关，而是似乎以一种开关式的方式起作用。当不添加可溶性诱导剂时，材料对细胞表面ICAM - 1的表达没有影响。这与细胞因子分泌情况类似，单独的材料不会诱导细胞因子分泌。当脂多糖或S - 27609与材料联合使用时，ICAM - 1的平均测量强度增加。在这个体外模型中，通过共聚焦显微镜测量的ICAM - 1染色是巨噬细胞激活的一个标志。我们的结果表明，通过ICAM - 1和细胞因子分泌测量的巨噬细胞激活程度对可溶性诱导剂比对聚乳酸平板的作用更敏感。
