Coordinate modulation of glucocorticoid receptor and glutaminase gene expression in LLC-PK1-F+ cells.
Coordinate modulation of glucocorticoid receptor and glutaminase gene expression in LLC-PK1-F+ cells.
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LLC-PK1-F 细胞中糖皮质激素受体和谷氨酰胺酶基因表达的协调调节。
DOI：
10.1152/ajpcell.1996.270.3.c825
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
Welbourne,T
中科院分区：
文献类型：
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作者：
Gowda,B;Sar,M;Mu,X;Cidlowski,J;Welbourne,T
在近端小管样LCC-PK 1-F+细胞中研究糖皮质激素受体对谷氨酰胺酶基因表达和相关谷氨酰胺代谢的影响。这些细胞表达功能性糖皮质激素受体，表现为与抗糖皮质激素受体抗体的免疫反应性、特异性配体结合以及暴露于地塞米松（10（-6）M）后氯霉素乙酰转移酶（CAT）报告基因活性增加14倍。地塞米松暴露18 h可使谷氨酰胺酶的mRNA和活性分别增加32%和42%（均P< 0.05，配对t检验），谷氨酰胺利用率也有小幅（9%）但显著的增加（P<0.05）。为了引起更大的反应，通过用表达大鼠糖皮质激素受体基因的质粒pMAMGR转染细胞来补充内源性糖皮质激素受体。转染细胞表达的CAT活性增加了39倍，地塞米松治疗，证实了更高水平的功能受体，但谷氨酰胺酶的mRNA和活性现在分别下降了34和32%，与15%的谷氨酰胺利用率下降后，18小时暴露于地塞米松。糖皮质激素受体mRNA在LLC-PK（1）-F+细胞中的表达在地塞米松作用后增加41%，但在转染后下降63%（均P<0.05）。这些发现与糖皮质激素受体基因调节谷氨酰胺酶基因表达和谷氨酰胺利用是一致的。
The effect of glucocorticoid receptor on glutaminase gene expression and related glutamine metabolism was studied in proximal tubule-like LCC-PK1-F+ cells. These cells express functional glucocorticoid receptors as demonstrated by immunoreactivity with antiglucocorticoid receptor antibody, specific ligand binding, and a 14-fold increase in chloramphenicol acetyltransferase (CAT) reporter gene activity after exposure to dexamethasone (10(-6)M). Dexamethasone exposure for 18 h increased glutaminase mRNA and activity by 32 and 42%, respectively (both P< 0.05, paired t-test), associated with a small (9%) but significant increase in glutamine utilization (P<0.05). In an effort to elicit a greater response, endogenous glucocorticoid receptors were supplemented by transfecting cells with a plasmid, pMAMGR, expressing the rat glucocorticoid receptor gene. Transfected cells expressed a 39-fold increase in CAT activity with dexamethasone treatment, confirming a higher level of functional receptors, but glutaminase mRNA and activity were now decreased by 34 and 32%, respectively, associated with a 15% fall in glutamine utilization after 18-h exposure to dexamethasone. This biphasic response in glutaminase gene expression was mirrored by glucocorticoid receptor mRNA that increased 41% after dexamethasone in LLC-PK(1)-F+ cells, but decreased 63% after transfection (both P<0.05). These findings are consonant with glucocorticoid receptor gene modulation of glutaminase gene expression and glutamine utilization.
糖皮质激素受体稳态和肾谷氨酰胺酶活性。
影响因子：
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作者：
Nam,M;Welbourne,TC
通讯作者：
Welbourne,TC