Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois, USA.
Department of Medicine and University of Wisconsin Carbone Cancer Center, University of Wisconsin-Madison, School of Medicine and Public Health, Madison, Wisconsin, USA.
Stem Cells. 2018 May;36(5):775-784. doi: 10.1002/stem.2781. Epub 2018 Jan 27.
Macrophages are crucial drivers of inflammatory corneal neovascularization and thus are potential targets for immunomodulatory therapies. We hypothesized that therapeutic use of cornea-derived mesenchymal stromal cells (cMSCs) may alter the function of macrophages. We found that cMSCs can modulate the phenotype and angiogenic function of macrophages. In vitro, cMSCs induce apoptosis of macrophages while preferentially promoting a distinct CD14 CD16 CD163 CD206 immunophenotype that has significantly reduced angiogenic effects based on in vitro angiogenesis assays. In vivo, application of cMSCs to murine corneas after injury leads to reduced macrophage infiltration and higher expression of CD206 in macrophages. Macrophages cocultured ("educated") by cMSCs express significantly higher levels of anti-angiogenic and anti-inflammatory factors compared with control macrophages. In vivo, injured corneas treated with cMSC-educated macrophages demonstrate significantly less neovascularization compared with corneas treated with control macrophages. Knocking down the expression of pigment epithelial derived factor (PEDF) in cMSCs significantly abrogates its modulating effects on macrophages, as shown by the reduced rate of apoptosis, decreased expression of sFLT-1/PEDF, and increased expression of vascular endothelial growth factor-A in the cocultured macrophages. Similarly, cMSCs isolated from PEDF knockout mice are less effective compared with wild-type cMSCs at inhibiting macrophage infiltration when applied to wild-type corneas after injury. Overall, these results demonstrate that cMSCs therapeutically suppress the angiogenic capacity of macrophages and highlight the role of cMSC secreted PEDF in the modulation of macrophage phenotype and function. Stem Cells 2018;36:775-784.
巨噬细胞是炎症性角膜新生血管形成的关键驱动因素,因此是免疫调节治疗的潜在靶点。我们假设角膜间充质基质细胞(cMSCs)的治疗性应用可能改变巨噬细胞的功能。我们发现 cMSCs 可以调节巨噬细胞的表型和血管生成功能。在体外,cMSCs 诱导巨噬细胞凋亡,同时优先促进一种独特的 CD14+CD16+CD163+CD206+免疫表型,根据体外血管生成测定,其血管生成作用显著降低。在体内,损伤后将 cMSCs 应用于小鼠角膜会导致巨噬细胞浸润减少,巨噬细胞中 CD206 表达增加。与对照巨噬细胞相比,与 cMSCs 共培养(“教育”)的巨噬细胞表达的抗血管生成和抗炎因子水平显著升高。在体内,用 cMSC 教育的巨噬细胞处理的受损角膜与用对照巨噬细胞处理的角膜相比,新生血管化明显减少。在 cMSCs 中敲低色素上皮衍生因子(PEDF)的表达可显著削弱其对巨噬细胞的调节作用,表现为凋亡率降低、sFLT-1/PEDF 表达减少以及共培养巨噬细胞中血管内皮生长因子-A 表达增加。同样,与野生型 cMSCs 相比,从 PEDF 敲除小鼠中分离的 cMSCs 在应用于损伤后的野生型角膜时,抑制巨噬细胞浸润的效果较差。总之,这些结果表明 cMSCs 可治疗性抑制巨噬细胞的血管生成能力,并强调了 cMSC 分泌的 PEDF 在调节巨噬细胞表型和功能中的作用。干细胞 2018;36:775-784。