Mechanisms of mineralocorticoid receptor-associated hypertension in diabetes mellitus: the role of O-GlcNAc modification
Mechanisms of mineralocorticoid receptor-associated hypertension in diabetes mellitus: the role of O-GlcNAc modification
复制标题
糖尿病盐皮质激素受体相关高血压的机制：O-GlcNAc 修饰的作用
DOI：
10.1038/s41440-022-01036-6
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发表时间：
2022-10-14
影响因子：
5.4
通讯作者：
Itoh, Hiroshi
中科院分区：
文献类型：
--
作者：
Jo, Rie;Shibata, Hirotaka;Itoh, Hiroshi
本研究通过检测与2型糖尿病密切相关的O-连接-N-乙酰葡萄糖胺（O-GlcNAc）对盐皮质激素受体（MR）的翻译后修饰，研究了盐皮质激素受体（MR）拮抗剂在难治性高血压和糖尿病肾病患者中的有益作用机制。HEK 293 T细胞中的免疫共沉淀试验表明，MR是O-GlcNAc修饰（O-GlcNAc化）的靶标。在高糖条件下，该受体的表达水平和转录活性与其O-GlcNAc化平行增加。液相色谱-串联质谱法显示MR在氨基酸295-307处的O-GlcNAc化。这些残基的点突变降低了O-GlcNAc化，以及MR的蛋白水平和转录活性。在db/db小鼠肾脏中，MR蛋白水平与组织的总体O-GlcNAc水平平行增加，同时伴有SGK 1 mRNA水平增加。给予6-重氮-5-氧代-L-正亮氨酸（一种O-GlcNAc化抑制剂）可降低db/db小鼠的组织O-GlcNAc水平和MR蛋白水平。因此，我们的研究表明，在体外和体内高葡萄糖条件下，MR的O-GlcNAc化直接增加受体的蛋白水平和转录活性。这些发现提供了MR作为预防糖尿病相关并发症的靶点的新机制。
This study investigated the mechanism underlying the beneficial effects of mineralocorticoid receptor (MR) antagonists in patients with resistant hypertension and diabetic nephropathy by examining post-translational modification of the MR by O-linked-N-acetylglucosamine (O-GlcNAc), which is strongly associated with type 2 diabetes. Coimmunoprecipitation assays in HEK293T cells showed that MR is a target of O-GlcNAc modification (O-GlcNAcylation). The expression levels and transcriptional activities of the receptor increased in parallel with its O-GlcNAcylation under high-glucose conditions. Liquid chromatography-tandem mass spectrometry revealed O-GlcNAcylation of the MR at amino acids 295-307. Point mutations in those residues decreased O-GlcNAcylation, and both the protein levels and transcriptional activities of MR. In db/db mouse kidneys, MR protein levels increased in parallel with overall O-GlcNAc levels of the tissue, accompanied by increased SGK1 mRNA levels. The administration of 6-diazo-5-oxo-L-norleucin, an inhibitor of O-GlcNAcylation, reduced tissue O-GlcNAc levels and MR protein levels in db/db mice. Thus, our study showed that O-GlcNAcylation of the MR directly increases protein levels and transcriptional activities of the receptor under high-glucose conditions in vitro and in vivo. These findings provide a novel mechanism of MR as a target for prevention of complications associated with diabetes mellitus.