Short small-interfering RNAs produce interferon-α-mediated analgesia

Our data suggest that (i) intrathecal administration of high doses of siRNA (≥10 μg) induced up-regulation of IFN-α in the spinal cord and produced analgesic effects through IFN-α, and (ii) IFN-α's analgesic effect is mediated via opioid receptors. Caution must be taken to avoid IFN-α-mediated analgesic effects of siRNAs in pain research.