Chen W W, Decker G L
Biochim Biophys Acta. 1982 Oct 8;718(2):185-92. doi: 10.1016/0304-4165(82)90218-5.
An accumulation of ceramide associated with the deficiency of acid ceramidase has been demonstrated in cultured diploid skin fibroblasts from a patient with Farber's disease. We extend this observation to investigate the lysosomal localization of accumulated ceramide and the abnormalities of lysosomes caused by this ceramide accumulation in Farber's diseased fibroblasts. We have found that the lysosomal fraction isolated from Farber's diseased fibroblasts by a subcellular fractionation procedure is markedly low in density compared with that of normal fibroblasts and is separated from other subcellular organelles. Ultrastructural studies of the isolated lysosomal fraction from Farber's diseased fibroblasts showed a mixed population of intact and swollen vesicles with a lysosomal appearance. Examination under high magnification clearly demonstrated lysosomal inclusions which contain lamellar and curvilinear membranes and resembled those seen in the intact fibroblasts. Subcellular localization of Farber's fibroblasts showed that the accumulated [3H]ceramide from the culture medium was predominantly localized in the lysosomal fraction with a markedly low density and very little was found to be associated with other cellular membranes. Our finding that ceramide is accumulated in the lysosomal fraction of Farber's fibroblasts and that these cells also show membranous inclusions strongly suggests that the accumulation of ceramide is directly involved in the formation of lysosomal inclusions.
在法伯病患者的培养二倍体皮肤成纤维细胞中，已证实存在与酸性神经酰胺酶缺乏相关的神经酰胺蓄积。我们扩展了这一观察结果，以研究法伯病成纤维细胞中蓄积的神经酰胺的溶酶体定位以及这种神经酰胺蓄积所导致的溶酶体异常。我们发现，通过亚细胞分级分离程序从法伯病成纤维细胞中分离出的溶酶体部分，与正常成纤维细胞相比，密度明显较低，且与其他亚细胞器分离。对从法伯病成纤维细胞中分离出的溶酶体部分进行超微结构研究，显示出具有溶酶体外观的完整和肿胀囊泡的混合群体。高倍镜下检查清楚地显示出溶酶体包涵体，其含有层状和曲线状膜，与完整成纤维细胞中所见的相似。法伯病成纤维细胞的亚细胞定位表明，培养基中蓄积的[3H]神经酰胺主要定位于密度明显较低的溶酶体部分，而与其他细胞膜相关的很少。我们的发现，即神经酰胺在法伯病成纤维细胞的溶酶体部分蓄积，且这些细胞还显示出膜性包涵体，强烈表明神经酰胺的蓄积直接参与了溶酶体包涵体的形成。
