PT - JOURNAL ARTICLE AU - Tomofumi Takenaka AU - Yuichiro Ohnishi AU - Masamichi Yamamoto AU - Daiki Setoyama AU - Haruhiko Kishima TI - Glycolytic System in Axons Supplement Decreased ATP Levels after Axotomy of the Peripheral Nerve AID - 10.1523/ENEURO.0353-22.2023 DP - 2023 Mar 01 TA - eneuro PG - ENEURO.0353-22.2023 VI - 10 IP - 3 4099 - http://www.eneuro.org/content/10/3/ENEURO.0353-22.2023.short 4100 - http://www.eneuro.org/content/10/3/ENEURO.0353-22.2023.full SO - eNeuro2023 Mar 01; 10 AB - Wallerian degeneration (WD) occurs in the early stages of numerous neurologic disorders, and clarifying WD pathology is crucial for the advancement of neurologic therapies. ATP is acknowledged as one of the key pathologic substances in WD. The ATP-related pathologic pathways that regulate WD have been defined. The elevation of ATP levels in axon contributes to delay WD and protects axons. However, ATP is necessary for the active processes to proceed WD, given that WD is stringently managed by auto-destruction programs. But little is known about the bioenergetics during WD. In this study, we made sciatic nerve transection models for GO-ATeam2 knock-in rats and mice. We presented the spatiotemporal ATP distribution in the injured axons with in vivo ATP imaging systems, and investigated the metabolic source of ATP in the distal nerve stump. A gradual decrease in ATP levels was observed before the progression of WD. In addition, the glycolytic system and monocarboxylate transporters (MCTs) were activated in Schwann cells following axotomy. Interestingly, in axons, we found the activation of glycolytic system and the inactivation of the tricarboxylic acid (TCA) cycle. Glycolytic inhibitors, 2-deoxyglucose (2-DG) and MCT inhibitors, a-cyano-4-hydroxycinnamic acid (4-CIN) decreased ATP and enhanced WD progression, whereas mitochondrial pyruvate carrier (MPC) inhibitors (MSDC-0160) did not change. Finally, ethyl pyruvate (EP) increased ATP levels and delayed WD. Together, our findings suggest that glycolytic system, both in Schwann cells and axons, is the main source of maintaining ATP levels in the distal nerve stump.