Foley-Comer Adam J, Herrick Sarah E, Al-Mishlab Talib, Prêle Cecilia M, Laurent Geoffrey J, Mutsaers Steven E
Department of Medicine, Royal Free and University College Medical School, The Rayne Institute, London, WC1E 6JJ, UK.
J Cell Sci. 2002 Apr 1;115(Pt 7):1383-9. doi: 10.1242/jcs.115.7.1383.
Regeneration of the mesothelium is unlike that of other epithelial-like surfaces, as healing does not occur solely by centripetal migration of cells from the wound edge. The mechanism of repair of mesothelium is controversial, but it is widely accepted, without compelling evidence, that pluripotent cells beneath the mesothelium migrate to the surface and differentiate into mesothelial cells. In this study we examined an alternative hypothesis, using in vivo cell-tracking studies, that repair involves implantation, proliferation and incorporation of free-floating mesothelial cells into the regenerating mesothelium. Cultured mesothelial cells, fibroblasts and peritoneal lavage cells were DiI- or PKH26-PCL-labelled and injected into rats immediately following mesothelial injury. Implantation of labelled cells was assessed on mesothelial imprints using confocal microscopy, and cell proliferation was determined by proliferating cell nuclear antigen immunolabelling. Incorporation of labelled cells, assessed by the formation of apical junctional complexes, was shown by confocal imaging of zonula occludens-1 protein. Labelled cultured mesothelial and peritoneal lavage cells, but not cultured fibroblasts, implanted onto the wound surface 3, 5 and 8 days after injury. These cells proliferated and incorporated into the regenerated mesothelium, as demonstrated by nuclear proliferating cell nuclear antigen staining and membrane-localised zonula occludens-1 expression, respectively. Furthermore, immunolocalisation of the mesothelial cell marker HBME-1 demonstrated that the incorporated, labelled lavage-derived cells were mesothelial cells and not macrophages as it had previously been suggested. This study has clearly shown that serosal healing involves implantation, proliferation and incorporation of free-floating mesothelial cells into the regenerating mesothelium.
间皮的再生不同于其他上皮样表面，因为愈合并非仅通过伤口边缘细胞向心迁移来实现。间皮的修复机制存在争议，但在没有确凿证据的情况下，人们普遍认为间皮下的多能细胞迁移至表面并分化为间皮细胞。在本研究中，我们使用体内细胞追踪研究检验了另一种假说，即修复过程涉及游离漂浮的间皮细胞植入、增殖并整合到再生的间皮中。将培养的间皮细胞、成纤维细胞和腹腔灌洗细胞用DiI或PKH26-PCL标记，并在间皮损伤后立即注射到大鼠体内。使用共聚焦显微镜在间皮印记上评估标记细胞的植入情况，并通过增殖细胞核抗原免疫标记来确定细胞增殖。通过闭合蛋白-1蛋白共聚焦成像显示，通过顶端连接复合体的形成评估标记细胞的整合情况。标记的培养间皮细胞和腹腔灌洗细胞，而非培养的成纤维细胞，在损伤后3、5和8天植入到伤口表面。这些细胞增殖并整合到再生的间皮中，分别通过细胞核增殖细胞核抗原染色和膜定位的闭合蛋白-1表达得以证明。此外，间皮细胞标志物HBME-1的免疫定位表明，整合的、标记的灌洗来源细胞是间皮细胞，而非如之前所认为的巨噬细胞。本研究清楚地表明，浆膜愈合涉及游离漂浮的间皮细胞植入、增殖并整合到再生的间皮中。
