Mitochondrial dysfunction is a key mechanism of cell death in hypoxic-ischemic brain injury. Neuronal pentraxin 1 (NP1) has been shown to play crucial roles in mitochondria-mediated neuronal death. However, the underlying mechanism(s) of NP1-induced mitochondrial dysfunction in hypoxia-ischemia (HI) remains obscure. Here, we report that NP1 induction following HI and its subsequent localization to mitochondria, leads to disruption of key regulatory proteins for mitochondrial biogenesis. Brain mitochondrial DNA (mtDNA) content and mtDNA-encoded subunit I of complex IV (mtCOX-1) expression was increased post-HI, but not the nuclear DNA-encoded subunit of complex II (nSDH-A). Up-regulation of mitochondrial proteins COXIV and HSP60 further supported enhanced mtDNA function. NP1 interaction with active Bax (Bax6A7) was increased in the brain after HI and in oxygen-glucose deprivation (OGD)-induced neuronal cultures. Importantly, NP1 colocalized with mitochondrial hexokinase II (mtHKII) following OGD leading to HKII dissociation from mitochondria. Knockdown of NP1 or SB216763, a GSK-3 inhibitor, prevented OGD-induced mtHKII dissociation and cellular ATP decrease. NP1 also modulated the expression of mitochondrial transcription factor A (Tfam) and peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α), regulators of mitochondrial biogenesis, following HI. Together, we reveal crucial roles of NP1 in mitochondrial biogenesis involving interactions with Bax[6A7] and mtHKII in HI brain injury.

线粒体功能障碍是缺氧缺血性脑损伤中细胞死亡的关键机制。神经元五聚蛋白 1 (NP1) 已被证明在线粒体介导的神经元死亡中起关键作用。然而，NP1 诱导的缺氧缺血 (HI) 线粒体功能障碍的潜在机制仍然不清楚。在这里，我们报告 HI 后的 NP1 诱导及其随后定位于线粒体，导致线粒体生物发生的关键调节蛋白的破坏。HI 后脑线粒体 DNA (mtDNA) 含量和复合物 IV (mtCOX-1) 表达的 mtDNA 编码亚基 I 增加，但复合物 II (nSDH-A) 的核 DNA 编码亚基不增加。线粒体蛋白 COXIV 和 HSP60 的上调进一步支持增强的 mtDNA 功能。在 HI 和氧-葡萄糖剥夺 (OGD) 诱导的神经元培养物中，NP1 与活性 Bax (Bax6A7) 的相互作用在大脑中增加。重要的是，在 OGD 后，NP1 与线粒体己糖激酶 II (mtHKII) 共定位，导致 HKII 从线粒体中解离。敲除 GSK-3 抑制剂 NP1 或 SB216763 可防止 OGD 诱导的 mtHKII 解离和细胞 ATP 减少。NP1 还调节线粒体转录因子 A 的表达（Tfam ) 和过氧化物酶体增殖物激活受体 γ coactivator-1α (PGC-1α)，线粒体生物发生的调节剂，在 HI 之后。总之，我们揭示了 NP1 在线粒体生物发生中的关键作用，涉及与 Bax[6A7] 和 mtHKII 在 HI 脑损伤中的相互作用。