Hind Laurel E, Lurier Emily B, Dembo Micah, Spiller Kara L, Hammer Daniel A
Department of Bioengineering, University of Pennsylvania, Philadelphia, PA.
School of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, PA.
Cell Mol Bioeng. 2016 Sep;9(3):455-465. doi: 10.1007/s12195-016-0435-x. Epub 2016 Apr 18.
Macrophages become polarized by cues in their environment and this polarization causes a functional change in their behavior. Two main subsets of polarized macrophages have been described. M1, or "classically activated" macrophages, are pro-inflammatory and M2, or "alternatively activated" macrophages, are anti-inflammatory. In this study, we investigated the motility and force generation of primary human macrophages polarized down the M1 and M2 pathways using chemokinesis assays and traction force microscopy on polyacrylamide gels. We found that M1 macrophages are significantly less motile and M2 macrophages are significantly more motile than unactivated M0 macrophages. We also showed that M1 macrophages generate significantly less force than M0 or M2 macrophages. We further found that M0 and M2, but not M1, macrophage force generation is dependent on ROCK signaling, as identified using the chemical inhibitor Y27632. Finally, using the chemical inhibitor blebbistatin, we found that myosin contraction is required for force generation by M0, M1, and M2 macrophages. This study represents the first investigation of the changes in the mechanical motility mechanisms used by macrophages after polarization.
巨噬细胞会因其周围环境中的信号而发生极化，这种极化会导致其行为发生功能性变化。已描述了极化巨噬细胞的两个主要亚群。M1型，即“经典活化”巨噬细胞，具有促炎作用；M2型，即“替代性活化”巨噬细胞，具有抗炎作用。在本研究中，我们使用趋化性测定法以及在聚丙烯酰胺凝胶上进行牵引力显微镜观察，研究了沿M1和M2途径极化的原代人巨噬细胞的运动性和力的产生。我们发现，与未活化的M0巨噬细胞相比，M1巨噬细胞的运动性显著降低，而M2巨噬细胞的运动性显著增强。我们还表明，M1巨噬细胞产生的力明显小于M0或M2巨噬细胞。我们进一步发现，如使用化学抑制剂Y27632所确定的那样，M0和M2巨噬细胞（而非M1巨噬细胞）的力的产生依赖于ROCK信号传导。最后，使用化学抑制剂blebbistatin，我们发现肌球蛋白收缩是M0、M1和M2巨噬细胞产生力所必需的。本研究首次对巨噬细胞极化后所使用的机械运动机制的变化进行了研究。
