PDF(Pubmed)
Abstract：
Elevated levels of D-2-hydroxyglutarate (D-2HG) and L-2-hydroxyglutarate (L-2HG) in the brain are associated with various pathological conditions, potentially contributing to neurological symptoms and neurodegeneration. Previous studies on animal models have revealed their capability to interfere with several cellular processes, including mitochondrial metabolism. Both enantiomers competitively inhibit the enzymatic activity of 2-oxoglutarate-dependent dioxygenases. These enzymes also execute several signaling cascades and regulate the level of covalent modifications on nucleic acids or proteins, e.g., methylation, hydroxylation, or ubiquitination, with an effect on epigenetic regulation of gene expression, protein stability, and intracellular signaling. To investigate the potential impact of 2HG enantiomers on human neuronal cells, we utilized the SH-SY5Y human neuroblastoma cell line as a model. We employed proton nuclear magnetic resonance (1H-NMR) spectroscopy of culture media that provided high-resolution insights into the changes in the content of metabolites. Concurrently, we performed biochemical assays to complement the 1H-NMR findings and to estimate the activities of lactate and 3-hydroxybutyrate dehydrogenases. Our results reveal that both 2HG enantiomers can influence the cellular metabolism of human neuroblastoma cells on multiple levels. Specifically, both enantiomers of 2HG comparably stimulate anaerobic metabolism of glucose and inhibit the uptake of several essential amino acids from the culture media. In this respect, both 2HG enantiomers decreased the catabolism capability of cells to incorporate the leucine-derived carbon atoms into their metabolism and to generate the ketone bodies. These results provide evidence that both enantiomers of 2HG have the potential to influence the metabolic and molecular aspects of human cells. Furthermore, we may propose that increased levels of 2HG enantiomers in the brain parenchyma may alter brain metabolism features, potentially contributing to the etiology of neurological symptoms in patients.
摘要：
大脑中D-2-羟基戊二酸（D-2HG）和L-2-羟基戊二酸（L-2HG）水平升高与各种病理状况有关，可能导致神经症状和神经变性。先前对动物模型的研究揭示了它们干扰多种细胞过程的能力，包括线粒体代谢.两种对映异构体竞争性地抑制2-氧戊二酸依赖性双加氧酶的酶活性。这些酶还执行几个信号级联，并调节核酸或蛋白质上的共价修饰水平。例如，甲基化,羟基化,或泛素化，对基因表达的表观遗传调控有影响，蛋白质稳定性，和细胞内信号。探讨2HG对映体对人神经细胞的潜在影响,我们使用SH-SY5Y人神经母细胞瘤细胞系作为模型。我们采用了培养基的质子核磁共振（1H-NMR）光谱，可提供对代谢物含量变化的高分辨率见解。同时,我们进行了生化测定以补充1H-NMR的发现，并估计乳酸和3-羟基丁酸脱氢酶的活性。我们的结果表明，两种2HG对映体都可以在多个水平上影响人神经母细胞瘤细胞的细胞代谢。具体来说,2HG的两种对映异构体可比较地刺激葡萄糖的厌氧代谢，并抑制培养基中几种必需氨基酸的摄取。在这方面,两种2HG对映体均降低了细胞的分解代谢能力，从而将亮氨酸衍生的碳原子整合到其代谢中并产生酮体。这些结果提供了2HG的两种对映异构体都有可能影响人细胞的代谢和分子方面的证据。此外，我们可能认为，脑实质中2HG对映体水平的增加可能会改变脑代谢特征，可能导致患者神经系统症状的病因。
