TY - JOUR 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. SP - 5565 LP - 5573 DO - 10.1523/JNEUROSCI.0815-06.2006 VL - 26 IS - 20 AU - Zixuan Cao AU - Ying Gao AU - J. Barney Bryson AU - Jianwei Hou AU - Nagarathnamma Chaudhry AU - Mustafa Siddiq AU - Jennifer Martinez AU - Tim Spencer AU - Jason Carmel AU - Ronald B. Hart AU - Marie T. Filbin Y1 - 2006/05/17 UR - http://www.jneurosci.org/content/26/20/5565.abstract N2 - 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. ER -