Hilaire N, Nègre-Salvayre A, Salvayre R
Department of Biochemistry, Faculty of Medicine in Rangueil, University Paul Sabatier, Toulouse, France.
FEBS Lett. 1993 Aug 16;328(3):230-4. doi: 10.1016/0014-5793(93)80933-l.
The sources and the catabolic pathways of cytoplasmic pools of triacylglycerols and cholesteryl esters have been comparatively investigated in cultured fibroblasts from normal subjects and from patients affected with neutral lipid storage disease (NLSD) and Wolman disease (WD). (i) Endogenously biosynthesized triacylglycerols and cholesteryl esters were degraded extra-lysosomally since they were catabolized at similar rates in normal and in WD fibroblasts. In NLSD fibroblasts, the degradation of endogenous triacylglycerols was severely deficient, whereas that of endogenous cholesteryl esters was in the normal range. (ii) Reconstituted high density lipoproteins (HDL) containing radiolabelled [3H]triolein and cholesteryl [14C]oleate were taken up by cultured fibroblasts and rapidly degraded in a non-lysosomal compartment. In NLSD fibroblasts the degradation of HDL-[3H]triolein was blocked whereas that of HDL-[14C]cholesteryl oleate was in the normal range. These data suggest that: (i) the cytoplasmic pools of triacylglycerols and cholesteryl esters originate from HDL uptake and from endogenous biosynthesis as well; (ii) cytoplasmic (non-lysosomal) triacylglycerols and cholesteryl esters are degraded by two separate catabolic pathways.
对正常受试者以及患有中性脂质贮积病（NLSD）和沃尔曼病（WD）的患者的培养成纤维细胞中三酰甘油和胆固醇酯的细胞质池来源及分解代谢途径进行了比较研究。（i）内源性生物合成的三酰甘油和胆固醇酯在溶酶体外被降解，因为它们在正常和成纤维细胞中以相似的速率被分解代谢。在NLSD成纤维细胞中，内源性三酰甘油的降解严重不足，而内源性胆固醇酯的降解在正常范围内。（ii）含有放射性标记的[3H]三油酸甘油酯和胆固醇[14C]油酸酯的重组高密度脂蛋白（HDL）被培养的成纤维细胞摄取，并在非溶酶体区室中迅速降解。在NLSD成纤维细胞中，HDL-[3H]三油酸甘油酯的降解被阻断，而HDL-[14C]胆固醇油酸酯的降解在正常范围内。这些数据表明：（i）三酰甘油和胆固醇酯的细胞质池既来源于HDL摄取，也来源于内源性生物合成；（ii）细胞质（非溶酶体）三酰甘油和胆固醇酯通过两条独立的分解代谢途径被降解。
