Targeting neuronal HK2 alleviates glutamate neurotoxicity and MCAO-induced ischemic brain injury

Acute ischemic stroke (AIS) persists as a major cause of death and long-term disability globally. The restricted efficacy of current neuroprotective treatments highlights the importance of identifying novel mechanisms of neuronal injury and therapeutic targets. Hexokinase 2 (HK2) has been shown to promote microglial Interleukin-1β (IL-1β) transcription and astrocytic exosome biogenesis after stroke. However, the role of HK2 in neuronal injury is largely unknown. Here, we found that excitatory glutamate selectively upregulates neuronal HK2 through both transcriptional and ubiquitin-proteasomal pathways. Inhibition of HK2 significantly reduces glutamate-induced neuronal injury. Additionally, knockdown of neuronal HK2 by adeno-associated viruses (AAVs) remarkably improved neurological function and alleviated brain injury following middle cerebral artery occlusion (MCAO) in mice. Further study revealed that suppressing HK2 notably decreases the formation of neuronal autophagosomes in vitro and in vivo. Moreover, HK2 directly interacts with Parkin, a key protein involved in mitophagy. Blocking the interaction between HK2 and Parkin effectively prevents glutamate-induced mitophagy. In conclusion, our findings suggest that neuronal HK2 exerts damaging effects in AIS via its non-metabolic function of promoting mitophagy. Therefore, these results suggest that inhibition of HK2 represents a promising therapeutic approach for neuroprotection.