Synthetic analogues of 2-oxo acids discriminate metabolic contribution of the 2-oxoglutarate and 2-oxoadipate dehydrogenases in mammalian cells and tissues
Synthetic analogues of 2-oxo acids discriminate metabolic contribution of the 2-oxoglutarate and 2-oxoadipate dehydrogenases in mammalian cells and tissues
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DOI：
10.1038/s41598-020-58701-4
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发表时间：
2020-02-05
影响因子：
4.6
通讯作者：
Bunik, Victoria, I
中科院分区：
文献类型：
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作者：
Artiukhov, Artem, V;Grabarska, Aneta;Bunik, Victoria, I
DHTKD1 编码的 2-氧代己二酸脱氢酶 (OADH) 的生物学意义仍然不清楚，因为它与普遍存在的 OGDH 编码的 2-氧代戊二酸脱氢酶 (OGDH) 存在催化冗余。在这项工作中，OADH 和 OGDH 的代谢贡献通过将具有不同 DHTKD1 表达的细胞/组织暴露于合成的同源 2-氧代二羧酸盐的磷酸盐类似物来区分。当 DHTKD1 和 OGDH 的细胞表达相当时，糖苷途径中间体和磷酸化糖丰富，而当 DHTKD1 表达量低于 OGDH 数量级时，烟酸和非磷酸化糖丰富。对具有不同 DHTKD1 表达的组织的酶制剂使用琥珀酰、戊二酰和己二酰膦酸酯，揭示了 OADH 和 OGDH 对体外 2-氧代己二酸和 2-氧代戊二酸氧化的贡献。在具有高和低 DHTKD1 表达的磷酸盐处理的细胞中，相应地，己二酸或戊二酸是受影响最大的代谢物。脂肪酸β-氧化的标志物己二酸主要被较短的、偏爱OGDH的膦酸降低，这与已知的β-氧化的OGDH依赖性一致。最长的、偏爱 OADH 的磷酸盐主要影响戊二酸水平。 OADH 抑制后糖和烟酸的耦合减少将 OADH 突变体中已知的葡萄糖稳态扰动与烟酸依赖性 NAD 代谢联系起来。
The biological significance of the DHTKD1-encoded 2-oxoadipate dehydrogenase (OADH) remains obscure due to its catalytic redundancy with the ubiquitous OGDH-encoded 2-oxoglutarate dehydrogenase (OGDH). In this work, metabolic contributions of OADH and OGDH are discriminated by exposure of cells/tissues with different DHTKD1 expression to the synthesized phosphonate analogues of homologous 2-oxodicarboxylates. The saccharopine pathway intermediates and phosphorylated sugars are abundant when cellular expressions of DHTKD1 and OGDH are comparable, while nicotinate and non-phosphorylated sugars are when DHTKD1 expression is order(s) of magnitude lower than that of OGDH. Using succinyl, glutaryl and adipoyl phosphonates on the enzyme preparations from tissues with varied DHTKD1 expression reveals the contributions of OADH and OGDH to oxidation of 2-oxoadipate and 2-oxoglutarate in vitro. In the phosphonates-treated cells with the high and low DHTKD1 expression, adipate or glutarate, correspondingly, are the most affected metabolites. The marker of fatty acid beta-oxidation, adipate, is mostly decreased by the shorter, OGDH-preferring, phosphonate, in agreement with the known OGDH dependence of beta-oxidation. The longest, OADH-preferring, phosphonate mostly affects the glutarate level. Coupled decreases in sugars and nicotinate upon the OADH inhibition link the perturbation in glucose homeostasis, known in OADH mutants, to the nicotinate-dependent NAD metabolism.