Shanghai Institute for Pediatric Research, Xin Hua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, P. R. China.
The 32 Ward of Oncology, Hunan Provincial Tumor Hospital, the Affiliated Tumor Hospital of Xiang Ya Medical School of Central University, Changsha, P. R. China.
PLoS One. 2014 Jan 24;9(1):e86100. doi: 10.1371/journal.pone.0086100. eCollection 2014.
Interstitial cells of Cajal (ICC) are critical to gastrointestinal motility. The phenotypes of ICC progenitors have been observed in the mouse gut, but whether they exist in the human colon and what abnormal changes in their quantity and ultrastructure are present in Hirschsprung's disease (HSCR) colon remains uncertain. In this study, we collected the surgical resection of colons, both proximal and narrow segments, from HSCR patients and normal controls. First, we identified the progenitor of ICC in normal adult colon using immunofluorescent localization techniques with laser confocal microscopy. Next, the progenitors were sorted to observe their morphology. We further applied flow cytometry to examine the content of ICC progenitors in these fresh samples. The ultrastructural changes in the narrow and proximal parts of the HSCR colon were observed using transmission electron microscopy (TEM) and were compared with the normal adult colon. The presumed early progenitor (c-Kit(low)CD34(+)Igf1r(+)) and committed progenitor (c-Kit(+)CD34(+)Igf1r(+)) of ICC exist in adult normal colon as well as in the narrow and proximal parts of the HSCR colon. However, the proportions of mature, early and committed progenitors of ICC were dramatically reduced in the narrow segment of the HSCR colon. The proportions of mature and committed progenitors of ICC in the proximal segment of the HSCR colon were lower than in the adult normal colon. Ultrastructurally, ICC, enteric nerves, and smooth muscle in the narrow segment of the HSCR colon showed severe injury, including swollen vacuola or ted mitochondria, disappearance of mitochondrial cristae, dilated rough endoplasmic reticulum, vesiculation and degranulation, and disappearance of the caveolae on the ICC membrane surface. The contents of ICC and its progenitors in the narrow part of the HSCR colon were significantly decreased than those of adult colon, which may be associated with HSCR pathogenesis.
Cajal 间质细胞（ICC）对胃肠道动力至关重要。已经在小鼠肠道中观察到 ICC 祖细胞的表型，但它们是否存在于人类结肠中，以及在先天性巨结肠症（HSCR）结肠中它们的数量和超微结构有何异常变化尚不确定。在这项研究中，我们收集了 HSCR 患者和正常对照者的结肠手术切除标本，包括近端和狭窄段。首先，我们使用激光共聚焦显微镜的免疫荧光定位技术鉴定了正常成人结肠中的 ICC 祖细胞。接下来，对祖细胞进行分选以观察其形态。我们进一步应用流式细胞术检查这些新鲜样本中 ICC 祖细胞的含量。使用透射电子显微镜（TEM）观察 HSCR 结肠狭窄和近端部分的超微结构变化，并与正常成人结肠进行比较。假定的 ICC 早期祖细胞（c-Kit(low)CD34(+)Igf1r(+））和定向祖细胞（c-Kit(+)CD34(+)Igf1r(+））存在于成人正常结肠以及 HSCR 结肠的狭窄和近端部分。然而，HSCR 结肠狭窄段 ICC 的成熟、早期和定向祖细胞比例显著降低。HSCR 结肠近端段 ICC 的成熟和定向祖细胞比例低于成人正常结肠。超微结构上，HSCR 结肠狭窄段的 ICC、肠神经和平滑肌均显示严重损伤，包括肿胀的空泡或线粒体、线粒体嵴消失、粗面内质网扩张、空泡化和脱粒以及 ICC 膜表面的 caveolae 消失。HSCR 结肠狭窄段 ICC 及其祖细胞的含量明显低于成人结肠，这可能与 HSCR 的发病机制有关。
