Department of Neurology, Huashan Hospital, Fudan University, Shanghai 200040, China.
Oxid Med Cell Longev. 2022 Jul 6;2022:5339361. doi: 10.1155/2022/5339361. eCollection 2022.
Asymmetric dimethylarginine (ADMA) is a nonselective nitric oxide synthase inhibitor. ADMA is thought to inhibit the production of nitric oxide (NO) by neurons after oxygen-glucose deprivation (OGD). The gap junction protein Connexin-36 (cx-36) is involved in the pathophysiology of stroke. We investigated whether ADMA could protect neurons from OGD insults by regulating the expression of cx-36.
Cultured rat cortical neuronal cells were used. Neurons were treated with OGD with or without ADMA pretreatment. The lactate dehydrogenase (LDH) release rate was used to assess neuronal injury. Intracellular NO levels were determined using 4-amino-5-methylamino-2',7'-difluorofluorescein diacetate. Western blotting was performed to detect cx-36 expression.
The LDH release rate increased in the supernatant of neurons after the OGD insult, whereas ADMA treatment reduced the LDH release rate. Intracellular NO levels increased following OGD treatment, and this increase was not inhibited by ADMA treatment. Expression of cx-36 was upregulated in neurons under OGD conditions, and treatment with ADMA downregulated the expression of cx-36.
ADMA protects neurons from OGD insult, and cx-36 downregulation may be a possible pathway involved in ADMA-mediated neuronal protection.
不对称二甲基精氨酸（ADMA）是一种非选择性的一氧化氮合酶抑制剂。ADMA 被认为在氧葡萄糖剥夺（OGD）后抑制神经元中一氧化氮（NO）的产生。缝隙连接蛋白 Connexin-36（cx-36）参与中风的病理生理过程。我们研究了 ADMA 是否可以通过调节 cx-36 的表达来保护神经元免受 OGD 损伤。
使用培养的大鼠皮质神经元细胞。用 OGD 处理神经元，或用 ADMA 预处理。用乳酸脱氢酶（LDH）释放率评估神经元损伤。用 4-氨基-5-甲基氨基-2'，7'-二氟荧光素二乙酸酯测定细胞内 NO 水平。通过 Western blot 检测 cx-36 的表达。
OGD 损伤后神经元上清液中的 LDH 释放率增加，而 ADMA 处理可降低 LDH 释放率。OGD 处理后细胞内 NO 水平升高，但 ADMA 处理不能抑制其升高。cx-36 在 OGD 条件下的神经元中表达上调，而 ADMA 处理可下调 cx-36 的表达。
ADMA 可保护神经元免受 OGD 损伤，cx-36 的下调可能是 ADMA 介导的神经元保护的一个可能途径。
