Çınar Ramazan, Nazıroğlu Mustafa
Department of Neuroscience, Health Science Institute, Suleyman Demirel University, Isparta, Turkey.
Neuroscience Research Center, Suleyman Demirel University, Isparta, Turkey.
Cell Mol Neurobiol. 2023 Apr;43(3):1335-1353. doi: 10.1007/s10571-022-01253-0. Epub 2022 Jul 15.
Alzheimer's disease (AD) is characterized by the increase of hippocampal Ca influx-induced apoptosis and mitochondrial oxidative stress (OS). The OS is a stimulator of TRPM2, although N-(p-amylcinnamoyl)anthranilic acid (ACA), 2-aminoethyl diphenylborinate (2/APB), and glutathione (GSH) are non-specific antagonists of TRPM2. In the present study, we investigated the protective roles of GSH and TRPM2 antagonist treatments on the amyloid β42 peptide (Aβ)-caused oxidative neurotoxicity and apoptosis in the hippocampus of mice with AD model. After the isolation of hippocampal neurons from the newborn mice, they were divided into five incubation groups as follows: control, ACA, Aβ, Aβ+ACA, and Aβ+GSH. The levels of apoptosis, hippocampus death, cytosolic ROS, cytosolic Zn, mitochondrial ROS, caspase-3, caspase-9, lipid peroxidation, and cytosolic Ca were increased in the primary hippocampus cultures by treatments of Aβ, although their levels were decreased in the neurons by the treatments of GSH, PARP-1 inhibitors (PJ34 and DPQ), and TRPM2 blockers (ACA and 2/APB). The Aβ-induced decreases of cell viability, cytosolic GSH, reduced GSH, and GSH peroxidase levels were also increased in the groups of Aβ+ACA and Aβ+GSH by the treatments of ACA and GSH. However, the Aβ-caused changes were not observed in the hippocampus of TRPM2-knockout mice. In conclusion, the present data demonstrate that maintaining the activation of TRPM2 is not only important for the quenching OS and neurotoxicity in the hippocampal neurons of mice with experimental AD but also equally critical to the modulation of Aβ-induced apoptosis. The possible positive effects of GSH and TRPM2 antagonist treatments on the amyloid-beta (Aβ)-induced oxidative toxicity in the hippocampus of mice. The ADP-ribose (ADPR) is produced via the stimulation of PARP-1 in the nucleus of neurons. The NUT9 in the C terminus of TRPM2 channel acts as a key role for the activation of TRPM2. The antagonists of TRPM2 are glutathione (GSH), ACA, and 2/APB in the hippocampus. The Aβ incubation-mediated TRPM2 stimulation increases the concentration of cytosolic-free Ca and Zn in the hippocampus. In turn, the increased concentration causes the increase of mitochondrial membrane potential (ΔΨm), which causes the excessive generations of mitochondria ROS and the decrease of cytosolic GSH and GSH peroxidase (GSH-Px). The ROS production and GSH depletion are two main causes in the neurobiology of Alzheimer's disease. However, the effect of Aβ was not shown in the hippocampus of TRPM2-knockout mice. The Aβ and TRPM2 stimulation-caused overload Ca entry cause apoptosis and cell death via the activations of caspase-3 (Casp/3) and caspase-9 (Casp/9) in the hippocampus. The actions of Aβ-induced oxidative toxicity were modulated in the primary hippocampus by the incubations of ACA, GSH, 2/APB, and PARP-1 inhibitors (PJ34 and DPQ). (↑) Increase. (↓) Decrease.
阿尔茨海默病（AD）的特征是海马体中钙离子内流诱导的细胞凋亡增加以及线粒体氧化应激（OS）。氧化应激是瞬时受体电位阳离子通道蛋白2（TRPM2）的刺激因素，尽管N-（对戊基肉桂酰基）邻氨基苯甲酸（ACA）、2-氨基乙基二苯基硼酸酯（2-APB）和谷胱甘肽（GSH）是TRPM2的非特异性拮抗剂。在本研究中，我们调查了谷胱甘肽和TRPM2拮抗剂处理对AD模型小鼠海马体中淀粉样β42肽（Aβ）引起的氧化神经毒性和细胞凋亡的保护作用。从新生小鼠分离出海马神经元后，将它们分为以下五个孵育组：对照组、ACA组、Aβ组、Aβ + ACA组和Aβ + GSH组。Aβ处理会使原代海马体培养物中的细胞凋亡、海马体死亡、胞质活性氧（ROS）、胞质锌、线粒体ROS、半胱天冬酶-3、半胱天冬酶-9、脂质过氧化和胞质钙水平升高，而GSH、聚（ADP-核糖）聚合酶-1抑制剂（PJ34和DPQ）以及TRPM2阻滞剂（ACA和2-APB）处理可使神经元中的这些水平降低。ACA和GSH处理使Aβ + ACA组和Aβ + GSH组中Aβ诱导的细胞活力、胞质GSH、还原型GSH和GSH过氧化物酶水平的降低也有所增加。然而，在TRPM2基因敲除小鼠的海马体中未观察到Aβ引起的变化。总之，目前的数据表明，维持TRPM2的激活不仅对实验性AD小鼠海马神经元中的氧化应激淬灭和神经毒性很重要，而且对Aβ诱导的细胞凋亡的调节同样至关重要。谷胱甘肽和TRPM2拮抗剂处理对小鼠海马体中淀粉样β（Aβ）诱导的氧化毒性可能具有积极作用。通过神经元细胞核中聚（ADP-核糖）聚合酶-1（PARP-1）的刺激产生ADP-核糖（ADPR）。TRPM2通道C末端的NUT9在TRPM2的激活中起关键作用。海马体中TRPM2的拮抗剂是谷胱甘肽（GSH）、ACA和2-APB。Aβ孵育介导的TRPM2刺激会增加海马体中游离胞质钙和锌的浓度。反过来，浓度的增加会导致线粒体膜电位（ΔΨm）升高，从而导致线粒体ROS过度产生以及胞质GSH和GSH过氧化物酶（GSH-Px）减少。ROS产生和GSH耗竭是阿尔茨海默病神经生物学中的两个主要原因。然而，Aβ的作用在TRPM2基因敲除小鼠的海马体中未表现出来。Aβ和TRPM2刺激引起的钙超载通过海马体中半胱天冬酶-3（Casp/3）和半胱天冬酶-9（Casp/9）的激活导致细胞凋亡和细胞死亡。在原代海马体中，ACA、GSH、2-APB和PARP-1抑制剂（PJ34和DPQ）的孵育调节了Aβ诱导的氧化毒性作用。（↑）增加。（↓）减少。
