Difference of pain vulnerability in adult and juvenile rodents: the role of SIRT1-mediated ClC-3 trafficking in sensory neurons.

Adults are more likely to suffer from chronic pain than minors, and its underlying mechanism remains unclear. SIRT1 an important age-related protein with function of lifespan extension; whether SIRT1 plays a role in the different pain vulnerability of adult and juvenile remains unclear. Here, we found that the expression level of SIRT1 in dorsal root ganglia (DRG) was related to the pain vulnerability. After nerve injury, the expression of SIRT1 in DRG was decreased in adult rodents whereas increased in juvenile rodents. Differential manipulation of SIRT1 abolished the different pain vulnerability between adult and juvenile rodents. Furthermore, SIRT1 interacted with ClC-3 channel and mediated ClC-3 membrane trafficking and Cl- current in DRG neurons. Differential manipulation of ClC-3 also abolished the difference in pain vulnerability between adult and juvenile rodents. The different anti-inflammatory ability determined the different change trends of SIRT1 and ClC-3 trafficking contributed to the different pain vulnerability in adult and juvenile rodents. In addition, the serum SIRT1 level was negatively correlated with the pain score in patients with chronic pain. These findings revealed the mechanism of the difference in pain vulnerability between adult and juvenile rodents and provided evidence for age-specific treatment of chronic pain.