Chen G L, Sutrina S L, Frayer K L, Chen W W
Arch Biochem Biophys. 1986 Feb 15;245(1):66-75. doi: 10.1016/0003-9861(86)90190-6.
Chloroquine, quinine, and NH4Cl are lysosomotropic agents which inhibit lysosomal function, apparently by raising the intralysosomal pH. We found that preincubation of cultured human skin fibroblasts with these lysosomotropic agents under serum-free conditions induced about a 10-fold stimulation of lipogenesis. A similar stimulatory effect on the incorporation of 3H2O, [14C]acetate, [14C]pyruvate, [14C]palmitate, and [14C]choline into cellular lipids was observed. The effect was both time and dose dependent, and was reversible. The concentrations of chloroquine, quinine, and NH4Cl resulting in half-maximal stimulation were about 3 microM, 30 microM, and 9 mM, respectively. At these concentrations, stimulation of lipogenesis correlated with impairment of lysosomal function. At a concentration of 10 microM chloroquine, the half-time for maximal stimulation was about 4 h. Most of the [14C]acetate was incorporated into phosphatidylcholine and other cellular lipids; less than 10% was found in cholesterol and cholesterol ester. Nevertheless, incorporation of [14C]acetate into cholesterol showed a chloroquine-induced stimulation parallel to that observed for phospholipids, suggesting that stimulation of both lipogenesis and cholesterogenesis occurred. The stimulatory effect of lysosomotropic agents on lipogenesis appeared to depend on active synthesis of cellular proteins. In the presence of cycloheximide, an inhibitor of protein synthesis; the stimulation was completely abolished.
氯喹、奎宁和氯化铵是溶酶体亲和剂，它们通过提高溶酶体内pH值来抑制溶酶体功能。我们发现，在无血清条件下用这些溶酶体亲和剂预孵育培养的人皮肤成纤维细胞，可诱导脂肪生成增加约10倍。观察到对3H2O、[14C]乙酸盐、[14C]丙酮酸盐、[14C]棕榈酸盐和[14C]胆碱掺入细胞脂质也有类似的刺激作用。该作用具有时间和剂量依赖性，且是可逆的。导致半数最大刺激的氯喹、奎宁和氯化铵浓度分别约为3 microM、30 microM和9 mM。在这些浓度下，脂肪生成的刺激与溶酶体功能的损害相关。在氯喹浓度为10 microM时，达到最大刺激的半衰期约为4小时。大部分[14C]乙酸盐掺入磷脂酰胆碱和其他细胞脂质中；在胆固醇和胆固醇酯中的含量不到10%。然而，[14C]乙酸盐掺入胆固醇显示出氯喹诱导的刺激，与观察到的磷脂刺激平行，表明脂肪生成和胆固醇生成均受到刺激。溶酶体亲和剂对脂肪生成的刺激作用似乎取决于细胞蛋白质的活性合成。在存在蛋白质合成抑制剂环己酰亚胺的情况下，刺激作用完全消失。
