Division of Pharmacology, Department of Neuroscience, School of Medicine, "Federico II" University of Naples, Via Pansini, 5, 80131, Naples, Italy.
IRCCS SDN Napoli, Italy.
Theranostics. 2020 Oct 27;10(26):12174-12188. doi: 10.7150/thno.48135. eCollection 2020.
Remote limb ischemic postconditioning (RLIP) is a well-established neuroprotective strategy able to protect the brain from a previous harmful ischemic insult through a sub-lethal occlusion of the femoral artery. Neural and humoral mechanisms have been proposed as mediators required to transmit the peripheral signal from limb to brain. Moreover, different studies suggest that protection observed at brain level is associated to a general genetic reprogramming involving also microRNAs (miRNAs) intervention. Brain ischemia was induced in male rats by transient occlusion of the middle cerebral artery (tMCAO), whereas RLIP was achieved by one cycle of temporary occlusion of the ipsilateral femoral artery after tMCAO. The expression profile of 810 miRNAs was evaluated in ischemic brain samples from rats subjected either to tMCAO or to RLIP. Among all analyzed miRNAs, there were four whose expression were upregulated after stroke and returned to basal level after RLIP, thus suggesting a possible involvement in RLIP-induced neuroprotection. These selected miRNAs were intracerebroventricularly infused in rats subjected to remote ischemic postconditioning, and their effect was evaluated in terms of brain damage, neurological deficit scores and expression of putative targets. Twenty-one miRNAs, whose expression was significantly affected by tMCAO and by tMCAO plus RLIP, were selected based on microarray microfluidic profiling. Our data showed that: (1) stroke induced an up-regulation of let-7a and miR-143 (2) these two miRNAs were involved in the protective effects induced by RLIP and (3) HIF1-α contributes to their protective effect. Indeed, their expression was reduced after RLIP and the exogenous intracerebroventricularly infusion of let-7a and miR-143 mimics prevented neuroprotection and HIF1-α overexpression induced by RLIP. Prevention of cerebral let-7a and miR-143 overexpression induced by brain ischemia emerges as new potential strategy in stroke intervention.
远程肢体缺血后处理（RLIP）是一种成熟的神经保护策略，通过对股动脉的亚致死性闭塞，能够保护大脑免受先前的有害缺血损伤。已经提出了神经和体液机制作为将肢体的外周信号传递到大脑的必需介质。此外，不同的研究表明，在大脑水平观察到的保护与涉及 microRNAs（miRNAs）干预的一般遗传重编程相关。通过短暂闭塞大脑中动脉（tMCAO）在雄性大鼠中诱导脑缺血，而 RLIP 通过 tMCAO 后对同侧股动脉进行一次循环短暂闭塞来实现。在接受 tMCAO 或 RLIP 的大鼠的缺血脑样本中评估了 810 种 miRNA 的表达谱。在所有分析的 miRNA 中，有四种 miRNA 的表达在中风后上调，并在 RLIP 后恢复到基础水平，因此表明它们可能参与 RLIP 诱导的神经保护。这些选定的 miRNA 被脑室内输注到接受远程缺血后处理的大鼠中，并根据脑损伤、神经功能缺损评分和推定靶标的表达来评估其作用。基于微阵列微流控分析，根据 tMCAO 和 tMCAO 加 RLIP 对 miRNA 表达的显著影响选择了 21 种 miRNA。我们的数据表明：（1）中风诱导 let-7a 和 miR-143 的上调；（2）这两种 miRNA 参与 RLIP 诱导的保护作用；（3）HIF1-α有助于其保护作用。事实上，它们的表达在 RLIP 后降低，并且外源性脑室内输注 let-7a 和 miR-143 模拟物可阻止 RLIP 诱导的神经保护和 HIF1-α过表达。预防脑缺血诱导的 let-7a 和 miR-143 过表达成为中风干预的新潜在策略。
