Zhang Heyu, Wang Yanzhe, He Zhiyi
Department of Neurology, The First Affiliated Hospital of China Medical University, Liaoning, China.
Front Neurosci. 2018 Sep 20;12:644. doi: 10.3389/fnins.2018.00644. eCollection 2018.
Glycine-histidine-lysine (GHK) is a human tripeptide that enhances wound healing, exerts neuroprotective effects against neurodegenerative disease, and improves tissue regeneration. This study examined whether GHK can alleviate injury due to intracerebral hemorrhage (ICH). Briefly, adult Wistar rats in GHK pretreatment groups were injected with GHK (1 or 10 mg/kg, i.p.) every 24 h for 3 days. Water content and intact neurons were detected in the rats 3 days after ICH, and the neurological deficit scores were examined in the rats at 4, 24, 72, and 168 h after ICH. Apoptosis was evaluated via caspase-3 immunohistochemistry, Nissl staining, and TUNEL assay. We also examined the effect of GHK on the expression of related proteins in SH-SY5Y cells via Western blotting. The expression of miR-339-5p was examined via real-time polymerase chain reaction analyses. GHK improved neurological deficits, reduced water content in the brain and inhibited neuronal apoptosis in ICH rats. It also prevented the apoptosis of SH-SY5Y cells with hemin treatment. Furthermore, GHK downregulated miR-339-5p expression, and overexpression of miR-339-5p partially reversed the anti-apoptotic effects of GHK in SH-SY5Y cells. Our findings suggest that the p38 MAPK pathway is involved in the GHK-induced downregulation of miR-339-5p, and that the miR-339-5p/VEGFA axis plays a role in preventing neuronal apoptosis following ICH injury. These findings indicate that GHK may represent a novel therapeutic strategy for ICH.
甘氨酸 - 组氨酸 - 赖氨酸（GHK）是一种人类三肽，可促进伤口愈合，对神经退行性疾病发挥神经保护作用，并改善组织再生。本研究检测了GHK是否能减轻脑出血（ICH）所致的损伤。简要地说，GHK预处理组的成年Wistar大鼠每24小时腹腔注射GHK（1或10 mg/kg），共3天。在ICH后3天检测大鼠的脑含水量和完整神经元，并在ICH后4、24、72和168小时检查大鼠的神经功能缺损评分。通过caspase - 3免疫组织化学、尼氏染色和TUNEL检测评估细胞凋亡。我们还通过蛋白质印迹法检测了GHK对SH - SY5Y细胞中相关蛋白表达的影响。通过实时聚合酶链反应分析检测miR - 339 - 5p的表达。GHK改善了ICH大鼠的神经功能缺损，降低了脑含水量并抑制了神经元凋亡。它还能防止经血红素处理的SH - SY5Y细胞凋亡。此外，GHK下调了miR - 339 - 5p的表达，而miR - 339 - 5p的过表达部分逆转了GHK对SH - SY5Y细胞的抗凋亡作用。我们的研究结果表明，p38丝裂原活化蛋白激酶（MAPK）通路参与了GHK诱导的miR - 339 - 5p下调，并且miR - 339 - 5p/VEGFA轴在预防ICH损伤后的神经元凋亡中发挥作用。这些发现表明，GHK可能代表一种针对ICH的新型治疗策略。
