APC-Cdh1 Regulates Neuronal Apoptosis Through Modulating Glycolysis and Pentose-Phosphate Pathway After Oxygen-Glucose Deprivation and Reperfusion.

Abstract

Anaphase-promoting complex (APC) with its coactivator Cdh1 is required to maintain the postmitotic state of neurons via degradation of Cyclin B1, which aims to prevent aberrant cell cycle entry that causes neuronal apoptosis. Interestingly, evidence is accumulating that apart from the cell cycle, APC-Cdh1 also involves in neuronal metabolism via modulating the glycolysis promoting enzyme, 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase-3 (PFKFB3). Here, we showed that under oxygen-glucose deprivation and reperfusion (OGD/R), APC-Cdh1 was decreased in primary cortical neurons. Likewise, the neurons exhibited enhanced glycolysis when oxygen supply was reestablished during reperfusion, which was termed as the "neuronal Warburg effect." In particular, the reperfused neurons showed elevated PFKFB3 expression in addition to a reduction in glucose 6-phosphate dehydrogenase (G6PD). Such changes directed neuronal glucose metabolism from pentose-phosphate pathway (PPP) to aerobic glycolysis compared to the normal neurons, resulting in increased ROS production and apoptosis during reperfusion. Pretreatment of neurons with Cdh1 expressing lentivirus before OGD could reverse this metabolic shift and attenuated ROS-induced apoptosis. However, the metabolism regulation and neuroprotection by Cdh1 under OGD/R condition could be blocked when co-transfecting neurons with Ken box-mut-PFKFB3 (which is APC-Cdh1 insensitive). Based on these data, we suggest that the Warburg effect may contribute to apoptotic mechanisms in neurons under OGD/R insult, and targeting Cdh1 may be a potential therapeutic strategy as both glucose metabolic regulator and apoptosis suppressor of neurons in brain injuries.