Retinoid X receptor α downregulation is required for tail and caudal spinal cord regeneration in the adult newt

This research investigates the role of retinoid X receptor α (RXRα) in tail and spinal cord regeneration in newts. The study found that RXRα protein levels decrease during regeneration, while a related protein, retinoic acid receptor β (RARβ), increases. The researchers used drugs to manipulate RXRα and RARβ activity. They discovered that preventing the decrease of RXRα with an RXR agonist, SR11237, inhibits tail and spinal cord regeneration. Similarly, blocking RARβ with an antagonist, LE135, also inhibits regeneration and interestingly, also prevents the normal downregulation of RXRα. The findings suggest a regulatory relationship between RXRα and RARβ. The proper balance of these proteins, with RXRα decreasing and RARβ increasing, is necessary for successful tail and spinal cord regeneration in newts.

• 1
  RXRα protein levels decrease during tail and spinal cord regeneration in adult newts, while RXRα mRNA levels increase.
• 2
  Pharmacological activation of RXR with SR11237 inhibits tail and spinal cord regeneration and prevents the downregulation of RXRα and upregulation of RARβ.
• 3
  Inhibition of RARβ with LE135 also inhibits regeneration and prevents the downregulation of RXRα, suggesting a regulatory feedback loop between the two receptors.