Cold pre-conditioning neuroprotection depends on TNF-α and is enhanced by blockade of interleukin-11
Version of Record online: 1 DEC 2010
© 2010 The Authors. Journal of Neurochemistry © 2010 International Society for Neurochemistry
Journal of Neurochemistry
Volume 117, Issue 2, pages 187–196, April 2011
How to Cite
Mitchell, H. M., White, D. M., Domowicz, M. S. and Kraig, R. P. (2011), Cold pre-conditioning neuroprotection depends on TNF-α and is enhanced by blockade of interleukin-11. Journal of Neurochemistry, 117: 187–196. doi: 10.1111/j.1471-4159.2010.07103.x
- Issue online: 1 APR 2011
- Version of Record online: 1 DEC 2010
- Accepted manuscript online: 10 NOV 2010 12:53PM EST
- Received September 15, 2010; revised manuscript received November 2, 2010; accepted November 3, 2010.
- innate immunity;
- slice culture
J. Neurochem. (2011) 117, 187–196.
Cold pre-conditioning reduces subsequent brain injury in small animals but the underlying mechanisms remain undefined. As hypothermia triggers systemic macrophage tumor necrosis factor alpha (TNF-α) production and other neural pre-conditioning stimuli depend on this cytokine, we reasoned that microglia and TNF-α would be similarly involved with cold pre-conditioning neuroprotection. Also, as slice cultures closely approximate their in vivo counterpart and include quiescent microglia, we used rat hippocampal slice cultures to confirm this hypothesis. Furthermore, inflammatory cytokine gene screening with subsequent PCR and immunostaining confirmation of targeted mRNA and related protein changes showed that cold pre-conditioning triggered a significant rise in TNF-α that localized to microglia and a significant rise in interleukin (IL)-11 that localized mainly to hippocampal pyramidal neurons and, more rarely, astrocytes. Importantly, co-stimulation with cold and IL-11, an anti-inflammatory cytokine that inhibits TNF-α expression, abrogated the otherwise evident protection. Instead, cold pre-conditioning coupled with blockade of IL-11 signaling further enhanced neuroprotection from that seen with cold pre-conditioning alone. Thus, physiological activation of brain pro-inflammatory cytokine signaling, and its amplification by inhibition of coincident anti-inflammatory cytokine signaling, may be opportune targets for the development of novel therapeutics that can mimic the protection seen in cold pre-conditioning.