Contributions of intercalated duct cells to the normal parenchyma of submandibular glands of adult rats
Contributions of intercalated duct cells to the normal parenchyma of submandibular glands of adult rats
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DOI：
10.1002/ar.1098
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发表时间：
2001-06-01
影响因子：
--
通讯作者：
Hand, AR
中科院分区：
文献类型：
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作者：
Man, YG;Ball, WD;Hand, AR
成年雄性大鼠下颌下腺的实质是自我更新的，大多数新形成的腺泡和颗粒管细胞被认为是从快速增殖的闰管（ID）室分化而来。由于LD细胞的表型多样性，基于其围产期分泌蛋白的不同表达，我们全身注射氚标记的胸苷24小时，并通过放射自显影和免疫细胞化学的定义的细胞表型超过1个月的追逐期间，在细胞中的胸苷分布的模式。在所有实质细胞隔室中均发现了增殖细胞;它们在ID中数量最多，并且主要在那些缺乏围产期蛋白SMG-B1、SMG-C和SMG-D免疫反应性的细胞中。ID细胞的标记指数（LI）在注射后7天达到峰值，然后在接下来的3周内下降。同时，在ID与腺泡和颗粒管的连接处的那些细胞中，以及在这些较大的实质元件内，LI显著增加。我们的结论是，ID细胞不反应围产期蛋白增殖扩大ID室，LD细胞在导管的末端分化成腺泡和颗粒导管细胞。我们的数据没有提供ID细胞二分化为纹状管（SD）细胞的证据;然而，在我们的制备物中观察到的少量排泄管（艾德）特征显示极高的LI（>25%），这表明更广泛的数据可能揭示了艾德在替代SD细胞中的前体作用。除了细胞从ID到其交界处的其他实质成分的逐步传代外，在典型的BI阴性腺泡中偶尔出现B1阳性腺泡（BAC）簇的报道表明了另一种途径，其中新扩增的ID的整个片段可能直接发育成重演的围产期BI反应细胞，根据成熟的腺泡细胞。与此相一致的建议，BAC有一个四倍以上的LI比典型的成人腺泡，此外，当通过电子显微镜免疫细胞化学分析，他们出现类似的新的围产期III型细胞超微结构和B1-免疫金标记的模式。与此相反，不太常见的腺泡表现为舌下腺表型，与典型的腺泡细胞LI没有显着差异。总的来说，我们的研究结果强调了非免疫反应ID细胞在正常细胞替代中的重要性，以及ID可以整体分化为替代腺泡以及在ID与腺泡和颗粒管的边界处增加单细胞的可能性。Anat Rec 263：202-214，2001年。(C)2001 Wiley-Liss，Inc.
The parenchyma of the submandibular gland in the adult male rat is self-renewing, with most newly formed acinar and granular duct cells believed to differentiate from the rapidly proliferating intercalated duct (ID) compartment. Since the LD cells are phenotypically diverse, based on their different expression of perinatal secretory proteins, we systemically injected tritiated thymidine for 24 hours, and followed the pattern of thymidine distribution in cells by autoradiography and immunocytochemistry of defined cellular phenotypes over a 1-month chase period. Proliferating cells were found within all parenchymal cell compartments; they were most numerous in ID, and primarily in those cells lacking immunoreactivity for the perinatal proteins SMG-B1, -C, and -D. The labeling index (LI) of the ID cells reached a peak at 7 days postinjection, and then decreased over the next 3 weeks. Concurrently, the LI increased significantly in those cells at the junctions of ID with both acini and granular ducts, and also within these larger parenchymal elements. We conclude that the ID cells not reactive for perinatal proteins proliferate to expand the ID compartment, and that LD cells at the ends of the ducts differentiate into both acinar and granular duct cells. Our data provide no evidence for the di differentiation of ID cells into cells of striated ducts (SD); however, the small number of excretory duct (ED) profiles seen in our preparations showed extremely high LI (>25%), suggesting that more extensive data might reveal a precursor role for the ED in replacement of SD cells. In addition to the stepwise passage of cells from ID to other parenchymal elements at their junctions, the reported occurrence of occasional clusters of B1-positive acini (BAC) among the typical BI-negative acini had suggested an alternate pathway, in which entire segments of newly expanded ID might develop directly into a recapitulated perinatal stage of BI-reactive cell, pursuant to becoming mature acinar cells. Consistent with this suggestion, the BAC had a fourfold greater LI than typical adult acini; moreover, when analyzed by electron microscopic immunocytochemistry, they appeared similar to the novel perinatal Type III cells both ultrastructurally and in their pattern of B1-immunogold labeling. In contrast, the less common acini showing a sublingual gland phenotype had no significant difference in LI from typical acinar cells. Overall, our results emphasize the importance of the nonimmunoreactive ID cells in normal cellular replacement, and the possibility that ID can undergo en bloc differentiation into replacement acini as well as incremental addition of single cells at the boundaries of ID with acini and with granular ducts. Anat Rec 263:202-214, 2001. (C) 2001 Wiley-Liss, Inc.