Silencing diacylglycerol kinase-theta expression reduces steroid hormone biosynthesis and cholesterol metabolism in human adrenocortical cells.
Silencing diacylglycerol kinase-theta expression reduces steroid hormone biosynthesis and cholesterol metabolism in human adrenocortical cells.
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DOI：
10.1016/j.bbalip.2013.12.005
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发表时间：
2014-04-04
期刊：
影响因子：
--
通讯作者：
Sewer MB
中科院分区：
文献类型：
--
作者：
Cai K;Lucki NC;Sewer MB
二酰基甘油激酶θ（DGKθ）通过合成核受体类固醇生成因子1（SF 1）的配体在调节肾上腺皮质类固醇生成中起关键作用。响应于cAMP信号级联的激活，核DGK活性迅速增加，促进PA介导的、SF 1依赖的皮质醇和脱氢表雄酮（DHEA）生物合成所需基因的转录。基于我们先前的工作，确定DGKθ作为产生SF 1激动剂的酶，我们建立了四环素诱导的H295 R稳定细胞系，表达针对DGKθ的短发夹RNA（shRNA），并表征了沉默DGKθ对肾上腺皮质基因表达的影响。全基因组DNA微阵列分析表明，沉默DGKθ表达改变了多个基因的表达，包括类固醇基因，核受体和参与鞘脂，磷脂和胆固醇代谢的基因。有趣的是，固醇调节元件结合蛋白（SREBP）的表达也受到抑制。与SREBP的抑制一致，我们观察到多个SREBP靶基因的下调，包括3-羟基-3-甲基戊二酰辅酶A还原酶（HMG-CoA red）和CYP 51，伴随着细胞胆固醇的降低。DGKθ基因敲低的细胞表现出代谢PA的能力降低，脂质和磷脂酶D（PLD）亚型下调。相反，抑制DGKθ增加了鞘脂代谢途径中几个基因的表达，包括酸性神经酰胺酶（ASAH 1）和鞘氨醇激酶（SPHK）。总之，这些数据表明DGKθ在人肾上腺皮质细胞中类固醇激素的产生中起重要作用。
Diacylglycerol kinase theta (DGKθ) plays a pivotal role in regulating adrenocortical steroidogenesis by synthesizing the ligand for the nuclear receptor steroidogenic factor 1 (SF1). In response to activation of the cAMP signaling cascade nuclear DGK activity is rapidly increased, facilitating PA-mediated, SF1-dependent transcription of genes required for cortisol and dehydroepiandrosterone (DHEA) biosynthesis. Based on our previous work identifying DGKθ as the enzyme that produces the agonist for SF1, we generated a tetracycline-inducible H295R stable cell line to express a short hairpin RNA (shRNA) against DGKθ and characterized the effect of silencing DGKθ on adrenocortical gene expression. Genome-wide DNA microarray analysis revealed that silencing DGKθ expression alters the expression of multiple genes, including steroidogenic genes, nuclear receptors and genes involved in sphingolipid, phospholipid and cholesterol metabolism. Interestingly, the expression of sterol regulatory element binding proteins (SREBPs) was also suppressed. Consistent with the suppression of SREBPs, we observed a down-regulation of multiple SREBP target genes, including 3-hydroxy-3-methylglutary coenzyme A reductase (HMG-CoA red) and CYP51, concomitant with a decrease in cellular cholesterol. DGKθ knockdown cells exhibited a reduced capacity to metabolize PA, with a down-regulation of lipin and phospholipase D (PLD) isoforms. In contrast, suppression of DGKθ increased the expression of several genes in the sphingolipid metabolic pathway, including acid ceramidase (ASAH1) and sphingosine kinases (SPHK). In summary, these data demonstrate that DGKθ plays an important role in steroid hormone production in human adrenocortical cells.
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DOI：
10.1126/science.1176709
发表时间：
2009-09-04
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Hait NC;Allegood J;Maceyka M;Strub GM;Harikumar KB;Singh SK;Luo C;Marmorstein R;Kordula T;Milstien S;Spiegel S
通讯作者：
Spiegel S
影响因子：
5.3
作者：
Campbell, Lioudmila A.;Faivre, Emily J.;Ingraham, Holly A.
通讯作者：
Ingraham, Holly A.
影响因子：
--
作者：
Bassett, MH;Suzuki, T;Rainey, WE
通讯作者：
Rainey, WE
影响因子：
2.1
作者：
Bassett, MH;White, PC;Rainey, WE
通讯作者：
Rainey, WE
DOI：
10.1073/pnas.77.12.7189
发表时间：
1980-01-01
期刊：
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA-BIOLOGICAL SCIENCES
影响因子：
--
作者：
FARESE, RV;SABIR, MA;LARSON, RE
通讯作者：
LARSON, RE