RT Journal Article SR Electronic T1 The Cytokine Interleukin-6 Is Sufficient But Not Necessary to Mimic the Peripheral Conditioning Lesion Effect on Axonal Growth JF The Journal of Neuroscience JO J. Neurosci. FD Society for Neuroscience SP 5565 OP 5573 DO 10.1523/JNEUROSCI.0815-06.2006 VO 26 IS 20 A1 Zixuan Cao A1 Ying Gao A1 J. Barney Bryson A1 Jianwei Hou A1 Nagarathnamma Chaudhry A1 Mustafa Siddiq A1 Jennifer Martinez A1 Tim Spencer A1 Jason Carmel A1 Ronald B. Hart A1 Marie T. Filbin YR 2006 UL http://www.jneurosci.org/content/26/20/5565.abstract AB Lesioning the peripheral branch of a dorsal root ganglion (DRG) neuron before injury of the central branch of the same neuron enables spontaneous regeneration of these spinal axons. This effect is cAMP and transcription dependent. Here, we show that the cytokine interleukin-6 (IL-6) is upregulated in DRG neurons after either a conditioning lesion or treatment with dibutyryl-cAMP. In culture, IL-6 allows neurons to grow in the presence of inhibitors of regeneration present in myelin. Importantly, intrathecal delivery of IL-6 to DRG neurons blocks inhibition by myelin both in vitro and in vivo, effectively mimicking the conditioning lesion. Blocking IL-6 signaling has no effect on the ability of cAMP to overcome myelin inhibitors. Consistent with this, IL-6-deficient mice respond to a conditioning lesion as effectively as wild-type mice. We conclude that IL-6 can mimic both the cAMP effect and the conditioning lesion effect but is not an essential component of either response.