Regulation of 3-hydroxy-3-methylglutaryl coenzyme A reductase activity and the esterification of cholesterol in human long term lymphoid cell lines.
Regulation of 3-hydroxy-3-methylglutaryl coenzyme A reductase activity and the esterification of cholesterol in human long term lymphoid cell lines.
复制标题
人长期淋巴细胞系中 3-羟基-3-甲基戊二酰辅酶 A 还原酶活性和胆固醇酯化的调节。
DOI：
10.1021/bi00648a011
复制
发表时间：
1976
期刊：
影响因子：
2.9
通讯作者：
N. Beratis
中科院分区：
文献类型：
--
作者：
H. Kayden;L. Hatam;N. Beratis
在已建立的正常人淋巴样细胞系中，研究了胆固醇生物合成中的速率控制酶的调节和[14C]油酸掺入胆固醇酯的调节，并与8例遗传性脂代谢异常患者的对照。3-羟基-3-甲基戊二酰辅酶A还原酶是胆固醇生物合成的控制酶，在正常人来源的淋巴细胞系中，在更换为脂肪缺乏的培养基后，其活性增加，并在48小时后达到峰值。在正常人来源的细胞系中加入全血清和低密度脂蛋白可抑制50%的3-羟基-3-甲基戊二酰辅酶A还原酶活性，但不能(几乎完全)抑制来自两个纯合子家族性高胆固醇血症患者来源的淋巴样细胞系的活性。当加入7-酮胆固醇时，正常和异常淋巴细胞系的3-羟基-3-甲基戊二酰辅酶A还原酶活力均明显受到抑制。在这些研究中，来自家族性高胆固醇血症杂合子患者的淋巴样细胞株很难与正常细胞区分开来。在正常人淋巴细胞系的培养液中加入低密度脂蛋白，可刺激[14C]油酸掺入胆固醇酯的脂肪酸部分。来自纯合子家族性高胆固醇血症患者的淋巴细胞系显示，即使在培养液中加入四倍量的低密度脂蛋白，[14C]油酸掺入到胆固醇酯中也没有增加；来自杂合性家族性高胆固醇血症患者的淋巴细胞系中[14C]油酸掺入略有增加。在淋巴细胞系中的这些研究结果与从正常人和纯合子家族性高胆固醇血症患者中获得的培养的人类成纤维细胞的结果进行了比较。在悬浮培养中维持的看似永久的淋巴样细胞系中胆固醇生物合成的调节研究提供了某些优于培养的皮肤成纤维细胞的优点，此外，还为研究同一患者的遗传异常提供了第二个组织。
The regulation of the rate-controlling enzyme in cholesterol biosynthesis and of the incorporation of [14C]oleate into cholesterol esters were studied in established lymphoid cell lines from normal subjects and compared with that of eight patients with genetic abnormalities of lipid metabolism. The activity of 3-hydroxy-3-methylglutaryl coenzyme A reductase, the rate-controlling enzyme in cholesterol biosynthesis, increases in lymphoid cell lines derived from normal subjects after the culture medium is changed to a lipid deficient medium and reaches peak activity after 48 hr. The addition of whole serum and of low density lipoproteins to cell lines derived from normal subjects suppressed 3-hydroxy-3-methylglutaryl coenzyme A reductase activity by 50%, but failed (almost completely) to suppress the activity in the lymphoid cell lines derived from two patients with homozygous familial hypercholesterolemia. When 7-ketocholesterol was added, the activity of 3-hydroxy-3-methylglutaryl coenzyme A reductase was markedly suppressed in both normal and abnormal lymphoid cell lines. Lymphoid cell lines derived from patients presumably heterozygous for familial hypercholesterolemia were difficult to distinguish from normal cells in these studies. The incorporation of [14C]oleate into the fatty acid fraction of cholesteryl esters was stimulated by the addition of the low density lipoproteins to the culture media of the lymphoid cell lines derived from the normal human subjects. The lymphoid cell lines derived from the patients with homozygous familial hypercholesterolemia showed no increase in [14C]oleate incorporation into cholesteryl esters even when a fourfold amount of low density lipoprotein was added to the media; a modest increase in [14C]oleate incorporation was observed in lymphoid cell lines from patients with heterozygous familial hypercholesterolemia. The results of these studies in lymphocyte cell lines are compared with the findings in cultured human fibroblasts obtained from normal subjects and from patients with homozygous familial hypercholesterolemia. Studies of the regulation of cholesterol biosynthesis in the apparently permanent lymphoid cell line maintained in suspension culture offer certain advantages over cultured skin fibroblasts, and, in addition, provide a second tissue for the study of genetic abnormalities from the same patient.