Cong Yushuang, Guo Ruichun, Li Chenglong, Li Qi, Qi Sihua
Department of Anesthesiology, The Fourth Affiliated Hospital of the Harbin Medical University, Harbin, China.
Department of Anesthesiology, Peking University People's Hospital, Beijing, China.
Front Pharmacol. 2025 Apr 1;16:1558457. doi: 10.3389/fphar.2025.1558457. eCollection 2025.
Cerebral ischemia-reperfusion (CIR) injury critically impacts stroke prognosis, yet effective therapeutic strategies remain limited. Irisin, an exercise-induced myokine, exhibits neuroprotective effects against cerebral ischemia. SIRT3, a mitochondrial deacetylase, is similarly implicated in mitigating ischemia-reperfusion injury. Given that irisin exerts protection via AMPK/PGC-1α pathway activation and SIRT3 acts downstream of PGC-1α , we hypothesized that SIRT3 mediates irisin's neuroprotection in CIR injury.
In vivo cerebral ischemia-reperfusion injury was modeled by inducing transient middle cerebral artery occlusion (MCAO) in mice, while in vitro CIR conditions were replicated using oxygen-glucose deprivation (OGD) in PC12 neuronal cultures. To elucidate the mechanistic role of SIRT3, targeted interventions were implemented: SIRT3 expression was silenced via transfection with small interfering RNA (siRNA), and its enzymatic activity was pharmacologically inhibited using 3-TYP, a selective SIRT3 inhibitor. Apoptotic were systematically evaluated through TUNEL staining, Western blot analysis of caspase-3, Bax and Bcl-2. Oxidative stress parameters, including malondialdehyde (MDA) levels and glutathione (GSH) content, were measured using colorimetric assays. Neurological function in mice was quantified using the modified Neurological Severity Score (mNSS).
Our results demonstrated that irisin mitigates apoptosis and oxidative stress by dose-dependently activating SIRT3 signaling. At the optimal dosage, irisin effectively restored SIRT3 expression levels, reduced neuronal damage, and improved neurological recovery in CIR injury models. Notably, the therapeutic effects of irisin were significantly attenuated by 3-TYP, a specific SIRT3 inhibitor. Further validation through in vitro experiments revealed that SIRT3 overexpression synergistically enhanced irisin-mediated protection against OGD-induced injury, whereas SIRT3 knockout substantially diminished its efficacy.
Our data shown that irisin exerted a protective role in CIR injury, at least in part, through SIRT3 activation. This study establishes the irisin/SIRT3 as a novel therapeutic target for ischemic stroke, providing mechanistic insights for future interventions.
脑缺血再灌注（CIR）损伤对中风预后有严重影响，但有效的治疗策略仍然有限。鸢尾素是一种运动诱导的肌动蛋白，对脑缺血具有神经保护作用。SIRT3是一种线粒体去乙酰化酶，同样与减轻缺血再灌注损伤有关。鉴于鸢尾素通过激活AMPK/PGC-1α途径发挥保护作用，且SIRT3在PGC-1α下游起作用，我们推测SIRT3介导鸢尾素在CIR损伤中的神经保护作用。
通过诱导小鼠短暂大脑中动脉闭塞（MCAO）建立体内脑缺血再灌注损伤模型，在PC12神经元培养物中使用氧糖剥夺（OGD）复制体外CIR条件。为阐明SIRT3的作用机制，实施了靶向干预：通过用小干扰RNA（siRNA）转染使SIRT3表达沉默，并使用选择性SIRT3抑制剂3-TYP在药理学上抑制其酶活性。通过TUNEL染色、caspase-3、Bax和Bcl-2的蛋白质印迹分析系统评估细胞凋亡。使用比色法测量氧化应激参数，包括丙二醛（MDA）水平和谷胱甘肽（GSH）含量。使用改良的神经严重程度评分（mNSS）对小鼠的神经功能进行量化。
我们的结果表明，鸢尾素通过剂量依赖性激活SIRT3信号减轻细胞凋亡和氧化应激。在最佳剂量下，鸢尾素有效地恢复了SIRT3表达水平，减少了神经元损伤，并改善了CIR损伤模型中的神经功能恢复。值得注意的是，特异性SIRT3抑制剂3-TYP显著减弱了鸢尾素的治疗效果。通过体外实验进一步验证表明，SIRT3过表达协同增强了鸢尾素介导的对OGD诱导损伤的保护作用，而SIRT3基因敲除则大大降低了其疗效。
我们的数据表明，鸢尾素在CIR损伤中发挥保护作用，至少部分是通过激活SIRT3。本研究将鸢尾素/SIRT3确立为缺血性中风的新型治疗靶点，为未来的干预措施提供了机制见解。
