Induction of microvillar hydrolase activities by cell density and exogenous differentiation inducers in an established kidney epithelial cell line (LLC-PK1).
Induction of microvillar hydrolase activities by cell density and exogenous differentiation inducers in an established kidney epithelial cell line (LLC-PK1).
复制标题
在已建立的肾上皮细胞系 (LLC-PK1) 中通过细胞密度和外源分化诱导剂诱导微绒毛水解酶活性。
DOI：
10.1002/jcp.1041210109
复制
发表时间：
1984
影响因子：
5.6
通讯作者：
Lever,JE
中科院分区：
文献类型：
--
作者：
Yoneyama,Y;Lever,JE
在LLC-PK 1肾上皮细胞系培养物中鉴定了肾脏近端小管顶端刷状缘膜的几种水解酶活性特征，即亮氨酸氨肽酶、γ-谷氨酰转肽酶、碱性磷酸酶、麦芽糖酶和海藻糖酶。一个协调的增加，这些酶的活性，观察到发展后的汇合细胞密度和功能膜极化。在加入称为分化诱导剂的化合物后，诱导了个体水解酶活性的进一步大幅度增加。六亚甲基二乙酰胺优先诱导海藻糖酶和麦芽糖酶活性增加。与对照提取物相比，诱导的海藻糖酶活性表现出增加的Vmax但相似的Km。诱导需要蛋白质合成，并依赖于诱导剂浓度和暴露时间。用N，N′-二甲基甲酰胺处理融合培养物可诱导麦芽糖酶、海藻糖酶、碱性磷酸酶和γ-谷氨酰转肽酶活性，而二甲基亚砜可诱导海藻糖酶和γ-谷氨酰转肽酶活性。加入磷酸二酯酶抑制剂1-甲基-3-异丁基黄嘌呤后，观察到亮氨酸氨肽酶和麦芽糖酶活性增加。N，N′-二甲基甲酰胺对海藻糖酶活性的诱导作用在去除诱导剂后的4天内是可逆的，但N，N ′-二乙酰胺的作用是不可逆的。这些结果表明，LLC-PK 1细胞系在细胞培养的规定条件下可重复地产生分化特异性特征，这可以通过称为细胞分化诱导剂的化学物质进行单独调节。
Several hydrolase activities characteristic of the apical brush border membrane of renal proximal tubule, leucine aminopeptidase, γ‐ glutamyl transpeptidase, alkaline phosphatase, maltase, and trehalase, were identified in cultures of the LLC‐PK1kidney epithelial cell line. A coordinate increase in activities of these enzymes was observed upon development of a confluent cell density and functional membrane polarization. Further large progressive increases in individual hydrolase activities were induced after the addition of compounds known as differentiation inducers. Hexamethylene bisacetamide preferentially induced increased trehalase and maltase activities. Induced trehalase activity exhibited an increased Vmaxbut a similar Kmcompared with activity in control extracts. Induction required protein synthesis and was dependent on inducer concentration and exposure time. Treatment of confluent cultures with N,N′‐dimethylformamide triggered an induction of maltase, trehalase, alkaline phosphatase, and γ‐glutamyl transpeptidase activities, whereas dimethylsulfoxide induced trehalase and γ‐glutamyl transpeptidase activities. Increased leucine aminopeptidase and maltase activities were observed after addition of the phosphodiesterase inhibitor 1‐methyl‐3‐isobutylxanthine. Induction of trehalase activity by N,N′‐dimethylformamide was reversible over a 4‐day period after removal of inducer, but effects of hexamethylene bisacetamide were irreversible. These results suggest that the LLC‐PK1cell line reproducibly develops differentiation‐specific characteristics under defined conditions in cell culture, which can be individually modulated by chemicals known as inducers of cell differentiation.