Zhu Xue-Xue, Su Jia-Bao, Wang Fang-Ming, Chai Xiao-Ying, Chen Guo, Xu An-Jing, Meng Xin-Yu, Qiu Hong-Bo, Sun Qing-Yi, Wang Yao, Lv Zhuo-Lin, Zhang Yuan, Liu Yao, Han Zhi-Jun, Li Na, Sun Hai-Jian, Lu Qing-Bo
Department of Basic Medicine, Department of Endocrinology, Affiliated Hospital of Jiangnan University, Jiangnan University, Wuxi, China.
Department of Basic Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu, China.
Clin Transl Med. 2025 Feb;15(2):e70221. doi: 10.1002/ctm2.70221.
The sodium pump Na+/K+-ATPase (NKA), an enzyme ubiquitously expressed in various tissues and cells, is a critical player in maintaining cellular ion homeostasis. Dysregulation of α1 subunit of NKA (NKAα1) has been associated with cardiovascular and metabolic disorders, yet the exact role of NKAα1 in diabetes-induced endothelial malfunction remains incompletely understood. The NKAα1 expression and NKA activity were examined in high-glucose (HG)-exposed endothelial cells (ECs) and mouse aortae, as well as in high-fat-diet (HFD)-fed mice. Acetylcholine (Ach) was utilised to assess endothelium-dependent relaxation (EDR) in isolated mouse aortae. We found that both NKAα1 protein and mRNA levels were significantly downregulated in the aortae of HFD-fed mice, and HG-incubated mouse aortae and ECs. Gain- and loss-of-function experiments revealed that NKAα1 preserves EDR by mitigating oxidative/nitrative stresses in ECs. Overexpression of NKAα1 facilitated EC viability, migration, and angiogenesis by inhibiting the overproduction of superoxide and peroxynitrite. Mechanistically, dysfunctional NKAα1 impaired autophagy process, and prevented the transfer of acyl-CoA synthetase long-chain family member 4 (ACSL4) to the lysosome for degradation, thereby resulting in lipid peroxidation and ferroptosis in ECs. Induction of ferroptosis and inhibition of the autophagy-lysosome pathway blocked the protective effects of NKAα1 on EDR. Eventually, we identified Hamaudol as a potent activator of NKAα1 by restraining the phosphorylation and endocytosis of NKAα1, restoring EDR in obese diabetic mice. Overall, NKAα1 facilitates the autophagic degradation of ACSL4 via the lysosomal pathway, preventing ferroptosis and oxidative/nitrative stress in ECs. NKAα1 may serve as an attractive candidate for the management of vascular disorders associated with diabetes. KEY POINTS: NKAα1 downregulation impairs endothelial function in diabetes by promoting oxidative/nitrative stress and ferroptosis. NKAα1 supports lysosomal degradation of ACSL4 via autophagy, preventing lipid peroxidation and ferroptosis. Hamaudol, an activator of NKAα1, restores endothelial relaxation in diabetic mice by inhibiting NKAα1 phosphorylation and endocytosis.
钠泵Na⁺/K⁺-ATP酶（NKA）是一种在各种组织和细胞中普遍表达的酶，在维持细胞离子稳态中起着关键作用。NKA的α1亚基（NKAα1）失调与心血管和代谢紊乱有关，然而NKAα1在糖尿病诱导的内皮功能障碍中的确切作用仍未完全明确。我们检测了高糖（HG）处理的内皮细胞（ECs）和小鼠主动脉以及高脂饮食（HFD）喂养小鼠中NKAα1的表达和NKA活性。利用乙酰胆碱（Ach）评估分离的小鼠主动脉中的内皮依赖性舒张（EDR）。我们发现，在HFD喂养小鼠的主动脉以及HG孵育的小鼠主动脉和ECs中，NKAα1蛋白和mRNA水平均显著下调。功能获得和功能丧失实验表明，NKAα1通过减轻ECs中的氧化/硝化应激来维持EDR。NKAα1的过表达通过抑制超氧化物和过氧亚硝酸盐的过量产生促进了ECs的活力、迁移和血管生成。从机制上讲，功能失调的NKAα1损害自噬过程，并阻止酰基辅酶A合成酶长链家族成员4（ACSL4）转移到溶酶体进行降解，从而导致ECs中的脂质过氧化和铁死亡。铁死亡的诱导和自噬-溶酶体途径的抑制阻断了NKAα1对EDR的保护作用。最终，我们通过抑制NKAα1的磷酸化和内吞作用，鉴定出哈马多为NKAα1的有效激活剂，恢复了肥胖糖尿病小鼠的EDR。总体而言，NKAα1通过溶酶体途径促进ACSL4的自噬降解，防止ECs中的铁死亡和氧化/硝化应激。NKAα1可能是治疗与糖尿病相关的血管疾病的有吸引力的候选药物。要点：NKAα1下调通过促进氧化/硝化应激和铁死亡损害糖尿病中的内皮功能。NKAα1通过自噬支持ACSL4的溶酶体降解，防止脂质过氧化和铁死亡。哈马多，一种NKAα1激活剂，通过抑制NKAα1磷酸化和内吞作用恢复糖尿病小鼠的内皮舒张。
