Axonal and Cell Body Protection By Nicotinamide Adenine Dinucleotide in Tumor Necrosis Factor-Induced Optic Neuropathy

作者：Kitaoka Yasushi; Hayashi Yasuhiro; Kumai Toshio; Takeda Hiroyuki; Munemasa Yasunari; Fujino Hiromi; Kitaoka Yuka; Ueno Satoki; Sadun Alfredo A; Lam Tim T

来源：Journal of Neuropathology and Experimental Neurology, 2009, 68(8): 915-927.

DOI：10.1097/nen.0b013e3181afecfa

• Axonal protection
• Microglia
• NAD
• Nmnat
• Optic nerve
• Tumor necrosis factor

Axonal degeneration often leads to the death of neuronal cell bodies. Previous studies have demonstrated the crucial role or nicotinamide adenine dinucleotide (NAD) biosyntlesis ill axonal protection of motor neurons, but the role of nicotinamide mononucleotide adenylytransferase 1 and NAD in optic nerve degeneration is unclear. Intravitreal injection of tumor necrosis factor (TNF) induces optic nerve degeneration and Subsequent loss of retinal ganglion cells. We found that the levels of nicotinamide mononlucleotide adenylyltransferase 1 mRNA and protein and of NAD were significantly decreased in the optic nerve after intravitreal injection of TNF in rats. The concomitant disorganization of microtubules with vacuoles and neurofilament accumulations in the axons were blocked by exogenous NAD treatment. Nicotinamide adenine dinucleotide also prevented TNF-induced axonal loss and delayed retinal ganglion cell loss 2 months after TNF injection. Microglia identified by immuohistochemistry were increased ill the optic nerves after TNF in injection; this increase was inhibited by NAD treatment. These results Suggest that axonal nicotinamide mononucleotide adenylyltransferase 1 and NAD declines are associated with TNF-induced optic nerve axonal degeneration and that axonal protection of NAD may be related to its inhibitory effect on microglial activation.

• 出版日期2009-8