Institute of Neuroscience, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, Hunan, China.
Department of Physiology, Medical College, University of South China, Hengyang, Hunan, China.
Clin Exp Pharmacol Physiol. 2018 Aug;45(8):832-840. doi: 10.1111/1440-1681.12955. Epub 2018 Jun 5.
Hyperglycaemia-induced neurotoxicity involved in the pathogenesis of diabetic encephalopathy and neuronal senescence is one of the worst effects of hyperglyceamic neurotoxicity. Cannabinoid receptor type 1 (CB1) has neuroprotective function in a series of neuropathy. Spermidine (Spd) has anti-aging function in many tissues. However, the role of Spd in hyperglyceamia-induced neuronal senescence remains unexplored. Therefore, we used high glucose (HG)-treated HT-22 cell as vitro model to investigate whether Spd protects neurons against hyperglyceamia-induced senescence and the mediatory role of CB1 receptor. The HT-22 cells were cultured in HG condition in the presence of different dose of Spd. Then, the viability of cells was measured by Cell Counting Kit-8 (CCK-8) assay. The senescence of cells was detected by Senescence-associated β-galactosidase (SA-β-Gal) staining. The expressions of p16 , p21 and CB1 receptor were measured by western blot. We found that Spd inhibited HG-induced neurotoxicity (the loss of cell viability) and senescence (the increase of SA-β-Gal positive cells, the upregulation of p16 and p21 ) in HT-22 cells. Also, Spd prevented HG-induced downregulation of CB1 receptor in HT-22 cells. Furthermore, we demonstrated that AM251 (a specific inhibitor of the CB1 receptor) reversed the protective effects of Spd on HG-induced neurotoxicity and senescence. These results indicated that Spd prevents HG-induced neurotoxicity and senescence via the upregulation of CB1 receptor. Our findings provide a promising future of Spd-based preventions and therapies for diabetic encephalopathy.
高血糖引起的神经毒性涉及糖尿病性脑病和神经元衰老的发病机制，是高血糖神经毒性最严重的影响之一。大麻素受体 1（CB1）在一系列神经病中具有神经保护功能。亚精胺（Spd）在许多组织中具有抗衰老作用。然而，Spd 在高血糖诱导的神经元衰老中的作用仍未被探索。因此，我们使用高葡萄糖（HG）处理的 HT-22 细胞作为体外模型，研究 Spd 是否保护神经元免受高血糖诱导的衰老，以及 CB1 受体的中介作用。将 HT-22 细胞在存在不同剂量 Spd 的 HG 条件下培养。然后，通过细胞计数试剂盒-8（CCK-8）测定法测量细胞活力。通过衰老相关 β-半乳糖苷酶（SA-β-Gal）染色检测细胞衰老。通过 Western blot 测定 p16、p21 和 CB1 受体的表达。我们发现 Spd 抑制 HG 诱导的神经毒性（细胞活力丧失）和衰老（SA-β-Gal 阳性细胞增加，p16 和 p21 上调）在 HT-22 细胞中。此外，Spd 防止 HG 诱导的 HT-22 细胞中 CB1 受体下调。此外，我们证明 AM251（CB1 受体的特异性抑制剂）逆转了 Spd 对 HG 诱导的神经毒性和衰老的保护作用。这些结果表明，Spd 通过上调 CB1 受体来防止 HG 诱导的神经毒性和衰老。我们的研究结果为基于 Spd 的糖尿病性脑病预防和治疗提供了有希望的未来。
