Nitric oxide prevents axonal degeneration by inducing HIF-1–dependent expression of erythropoietin

SC Keswani, M Bosch-Marcé, N Reed… - Proceedings of the …, 2011 - National Acad Sciences
SC Keswani, M Bosch-Marcé, N Reed, A Fischer, GL Semenza, A Höke
Proceedings of the National Academy of Sciences, 2011National Acad Sciences
Nitric oxide (NO) is a signaling molecule that can trigger adaptive (physiological) or
maladaptive (pathological) responses to stress stimuli in a context-dependent manner. We
have previously reported that NO may signal axonal injury to neighboring glial cells. In this
study, we show that mice deficient in neuronal nitric oxide synthase (nNOS−/−) are more
vulnerable than WT mice to toxin-induced peripheral neuropathy. The administration of NO
donors to primary dorsal root ganglion cultures prevents axonal degeneration induced by …
Nitric oxide (NO) is a signaling molecule that can trigger adaptive (physiological) or maladaptive (pathological) responses to stress stimuli in a context-dependent manner. We have previously reported that NO may signal axonal injury to neighboring glial cells. In this study, we show that mice deficient in neuronal nitric oxide synthase (nNOS−/−) are more vulnerable than WT mice to toxin-induced peripheral neuropathy. The administration of NO donors to primary dorsal root ganglion cultures prevents axonal degeneration induced by acrylamide in a dose-dependent manner. We demonstrate that NO-induced axonal protection is dependent on hypoxia-inducible factor (HIF)-1–mediated transcription of erythropoietin (EPO) within glial (Schwann) cells present in the cultures. Transduction of Schwann cells with adenovirus AdCA5 encoding a constitutively active form of HIF-1α results in amelioration of acrylamide-induced axonal degeneration in an EPO-dependent manner. Mice that are partially deficient in HIF-1α (HIF-1α+/−) are also more susceptible than WT littermates to toxic neuropathy. Our results indicate that NO→HIF-1→EPO signaling represents an adaptive mechanism that protects against axonal degeneration.
National Acad Sciences