低氧后处理（HPC）已被报道可以增强Parkin催化线粒体泛素化，以恢复海马CA1对于暂时性全脑缺血（tGCI）的线粒体自噬。然而，在HPC介导的tGCI后，泛素化的线粒体是如何被清除的分子机制尚不清楚。本研究旨在调查HPC是否通过Parkin诱导的K63链聚泛素化（K63-Ub）来激活tumor necrosis factor associated factor family member associated nuclear factor κB activator-binding kinase 1（TBK1）以恢复tGCI后自噬。我们发现，在tGCI后，HPC维持TBK1表达，促进线粒体中p62和TBK1的磷酸化，并增强它们在CA1的线粒体中的招募。然而，这些效应被TBK1抑制剂BX795部分抵消。26h的再灌注后，线粒体TBK1的K63-Ub被干扰，这一影响被HPC所逆转。HPC维持了线粒体TBK1的K63-Ub依赖于Parkin，而AAV介导的Prkn小干扰RNA下调Parkin之后，K63-Ub的维持反而受到反击，beg down级别降低的TBK1激活和线粒体p62磷酸化。这项创新性研究表明，HPC通过Parkin介导的K63-Ub维持TBK1的方式促进了TBK1的磷酸化，并激活了p62以恢复线粒体自噬，从而缓解了tGCI后CA1中的神经元损伤。版权所有©2023 The Authors。Elsevier Inc. 保留所有权利。

Hypoxic postconditioning (HPC) has been reported to enhance Parkin-catalyzed mitochondrial ubiquitination to restore mitophagy in hippocampal CA1 against transient global cerebral ischemia (tGCI). However, the molecular mechanism leading ubiquitinated mitochondria to final clearance during HPC-mediated mitophagy after tGCI is unclear. This study aims to investigate whether HPC restores mitophagy after tGCI through Parkin-induced K63-linked poly-ubiquitination (K63-Ub) to activate tumor necrosis factor associated factor family member associated nuclear factor κB activator -binding kinase 1 (TBK1) in CA1 of male rats. We found that HPC maintained TBK1 expression, promoted p62 and TBK1 phosphorylation in mitochondria, and enhanced their recruitments to mitochondria in CA1 after tGCI. However, these effects were partially abolished by TBK1 inhibitor BX795. K63-Ub of mitochondrial TBK1 was disturbed at 26 h of reperfusion after tGCI, which was reversed by HPC. The maintenance of K63-Ub of mitochondrial TBK1 induced by HPC was counteracted under Parkin knockdown with AAV-mediated Prkn small-interfering RNA, accompanied by the suppression on TBK1 activation and the reduction of mitochondrial p62 phosphorylation. This innovative study indicated that HPC maintained K63-Ub of TBK1 in a Parkin-dependent manner to promote TBK1 phosphorylation, and then phosphorylated TBK1 activated p62 to restore mitophagy, thereby alleviating neuronal damage in CA1 after tGCI.Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.