Hyperglycemia-reduced NAD+ biosynthesis impairs corneal epithelial wound healing in diabetic mice
Hyperglycemia-reduced NAD+ biosynthesis impairs corneal epithelial wound healing in diabetic mice
复制标题
高血糖导致的 NAD 生物合成减少会损害糖尿病小鼠的角膜上皮伤口愈合。
DOI：
10.1016/j.metabol.2020.154402
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发表时间：
2021-01-01
影响因子：
9.8
通讯作者：
Shi, Weiyun
中科院分区：
文献类型：
--
作者：
Li, Ya;Li, Jing;Shi, Weiyun
目的：烟酰胺腺嘌呤二核苷酸（NAD）是参与多种生理和病理生理过程的重要分子。在糖尿病角膜中，NAD（+）消耗酶SIRT 1下调，并导致伤口愈合延迟。然而，高血糖对角膜NAD（+）生物合成的影响仍然难以捉摸。本研究旨在探讨糖尿病小鼠角膜上皮细胞NAD（+）生物合成与糖尿病小鼠角膜损伤愈合延迟的关系。用NAD/NADH定量试剂盒测定角膜上皮细胞NAD（+）含量。分析1型DM小鼠和2型DM患者中NAD（+）生物合成关键酶的表达。结果：高脂血症降低了1型DM小鼠和2型DM患者角膜上皮细胞NAD（+）含量和NAMPT表达，并抑制了2型DM患者角膜上皮细胞NAD（+）含量和NAMPT表达。在正常小鼠中，通过siRNA或FK 866局部敲除NAMPT一致地再现了延迟的角膜上皮伤口愈合。此外，补充NAD（+）可恢复培养角膜上皮细胞因FK 866或高糖处理而受损的增殖和迁移能力。此外，在DM小鼠中，NAD（+）及其前体烟酰胺单核苷酸和烟酰胺核苷也促进角膜上皮和神经再生，同时恢复上皮中SIRT 1和磷酸化EGFR、AKT和ERK 1/2的表达以及角膜敏感性。结论：糖尿病小鼠高血糖可导致NAD（+）生物合成减少，并影响创面愈合。补充NAD（+）及其前体物可促进糖尿病角膜伤口愈合和神经再生，这可能为糖尿病角膜并发症的治疗提供一种新的治疗策略。(C)2020由Elsevier Inc.出版。
Objective: Nicotinamide adenine dinucleotide (NAD) is an essential molecule participating in multiple physiological and pathophysiological processes. In diabetic cornea, the NAD(+)-consuming enzyme SIRT1 was down regulated and contributed to the delayed wound healing. However, the impact of hyperglycemia on corneal NAD(+) biosynthesis remained elusive. This study was to investigate the relationship of NAD(+) biosynthesis and the delayed corneal wound healing in diabetic mice.Methods: Type 1 diabetes mellitus (DM) mice were induced by streptozotocin and corneal epithelial wound healing models were constructed by epithelial scraping. The NAD(+) contents of corneal epithelium were measured using the NAD/NADH quantification kit. Expression of key enzymes involved in the NAD(+) biosynthesis in type 1 DM mice and type 2 DM patients were analyzed. The nicotinamide phosphoribosyltransferase (NAMPT)-specific siRNA and the selective inhibitor FK866 were used to achieve the blockade of NAMPT, whereas exogenous NAD(+) and its precursors were replenished to the corneal epithelial cells and DM mice.Results: Hyperglycemia attenuated NAD(+) content and NAMPT expression in the corneal epithelium of both type 1 DM mice and type 2 DM patients. Local knockdown of NAMPT by siRNA or FK866 consistently recapitulated the delayed corneal epithelial wound healing in normal mice. Moreover, NAD(+) replenishment recovered the impaired proliferation and migration capacity by either FK866 or high glucose treatment in cultured corneal epithelial cells. Furthermore, in DM mice, NAD(+) and its precursors nicotinamide mononucleotide and nicotinamide riboside also facilitated corneal epithelial and nerve regeneration, accompanied with the recovered expression of SIRT1 and phosphorylated EGFR, AKT, and ERK1/2 in epithelium and corneal sensitivity. Conclusion: Hyperglycemia-reduced NAD(+) biosynthesis and contributed to the impaired epithelial wound healing in DM mice. The replenishment of NAD(+) and its precursors facilitated diabetic corneal wound healing and nerve regeneration, which may provide a novel therapeutic strategy for the treatment of diabetic corneal complications. (C) 2020 Published by Elsevier Inc.