Tianjin State Key Laboratory of Modern Chinese Medicine, Tianjin Key Laboratory of Traditional Chinese Medicine Pharmacology, Tianjin University of Traditional Chinese Medicine, #10 Boyanghu Road, Jinghai District, Tianjin, 301617, China.
Tianjin State Key Laboratory of Modern Chinese Medicine, Tianjin Key Laboratory of Traditional Chinese Medicine Pharmacology, Tianjin University of Traditional Chinese Medicine, #10 Boyanghu Road, Jinghai District, Tianjin, 301617, China; Key Laboratory of Pharmacology of Traditional Chinese Medical Formulae, Ministry of Education, Tianjin University of Traditional Chinese Medicine, Tianjin, 301617, China.
J Ethnopharmacol. 2021 May 10;271:113898. doi: 10.1016/j.jep.2021.113898. Epub 2021 Feb 6.
Activation of autophagy has been implicated in cerebral ischiemia/reperfusion (I/R) injury. Salvianolate lyophilized injection (SLI) has been widely used in the clinical treatment of cerebrovascular disease in China. Whether SLI has any influence on the activation of autophagy in cerebral I/R injury remains elusive.
The aim of this study were to assess whether SLI attenuates I/R-induced brain injury and evaluate its associated mechanisms.
Focal cerebral ischaemia was induced by middle cerebral artery occlusion (MCAO). SLI (21 mg/kg) was injected intravenously at the beginning of the reperfusion period and 24 and 48 h after ischaemia. The effects of SLI on brain injury were detected according to infarct volume, neurological score, brain oedema, and HE and TUNEL staining at 72 h post-MCAO. Western blotting was used to detect alterations in the autophagy-relevant proteins LC3, Beclin-1, mTOR, p62, Lamp-1, and CTSD in the ipsilateral cortex at 24 or 72 h post-MCAO.
We first demonstrated that SLI significantly alleviated the infarct volume, neurological deficits, and brain oedema, and reduced the number of TUNEL-positive cells in rats with cerebral I/R injury. Next, we found that SLI has a bidirectional regulatory effect on autophagy: early-stage (24 h) cerebral ischaemia promotes the activation of autophagy and developmental-stage (72 h) cerebral ischaemia has an inhibitory effect. SLI enhanced I/R-induced autophagy as evidenced by the increased expression level of the autophagy marker protein LC3Ⅱ, as well as the decreased expression of mTOR and the autophagy substrate protein p62, but there was no change in lysosomal activity at 24 h after I/R-induced injury. Moreover, SLI also inhibited excessive activation of autophagy at 72 h after I/R-induced injury, which manifested as downregulating LC3Ⅱ expression, upregulating mTOR and p62 expression, and inhibiting lysosomal activity.
SLI has a protective effect on cerebral ischaemia/reperfusion injury, which may be mediated by the autophagy-lysosome pathway.
自噬的激活已被牵涉到脑缺血/再灌注（I/R）损伤中。丹参多酚酸盐冻干注射液（SLI）已在中国广泛用于治疗脑血管疾病。SLI 是否对脑 I/R 损伤中的自噬激活有影响仍不清楚。
本研究旨在评估 SLI 是否能减轻 I/R 引起的脑损伤，并评估其相关机制。
通过大脑中动脉闭塞（MCAO）诱导局灶性脑缺血。在再灌注期开始时及缺血后 24 和 48 小时，静脉注射 SLI（21mg/kg）。在 MCAO 后 72 小时，根据梗塞体积、神经学评分、脑水肿、HE 和 TUNEL 染色来检测 SLI 对脑损伤的影响。在 MCAO 后 24 或 72 小时，通过 Western blot 检测同侧皮质中自噬相关蛋白 LC3、Beclin-1、mTOR、p62、Lamp-1 和 CTSD 的变化。
我们首先证明 SLI 能显著减轻脑 I/R 损伤大鼠的梗塞体积、神经功能缺损和脑水肿，并减少 TUNEL 阳性细胞的数量。接下来，我们发现 SLI 对自噬有双向调节作用：早期（24 小时）脑缺血促进自噬的激活，而晚期（72 小时）脑缺血则具有抑制作用。SLI 通过增加自噬标志物蛋白 LC3Ⅱ的表达水平，以及降低 mTOR 和自噬底物蛋白 p62 的表达水平，增强 I/R 诱导的自噬，但在 I/R 损伤后 24 小时，溶酶体活性没有变化。此外，SLI 还抑制了 I/R 诱导损伤后 72 小时自噬的过度激活，表现为下调 LC3Ⅱ的表达，上调 mTOR 和 p62 的表达，并抑制溶酶体活性。
SLI 对脑缺血/再灌注损伤具有保护作用，其机制可能与自噬-溶酶体途径有关。
