Expression patterns of T-type Cav3.2 channel and insulin-like growth factor-1 receptor in dorsal root ganglion neurons of mice after sciatic nerve axotomy

Neuroreport. 2016 Oct 19;27(15):1174-81. doi: 10.1097/WNR.0000000000000676.

Abstract

Substantial evidence indicates that T-type Cav3.2 channel and insulin-like growth factor-1 (IGF-1) contribute to pain hypersensitivity within primary sensory nerves. A recent study suggested that activation of IGF-1 receptor (IGF-1R) could increase Cav3.2 channel currents and further contribute to inflammatory pain sensitivity. However, the expression patterns of Cav3.2 and IGF-1R and their colocalization in dorsal root ganglion (DRG) in chronic neuropathic pain condition remain unknown. In this study, we explored expression patterns of Cav3.2, IGF-1R and their colocalization, and whether phenotypic switch occurs in a subpopulation of Cav3.2 or IGF-1R neurons in mouse DRGs after sciatic nerve axotomy with immunofluorescence, real-time reverse transcription-PCR, and western blot assays. We found that expressions of Cav3.2 and IGF-1R, and their colocalization were not increased in DRGs of mice following axotomy. In addition, Cav3.2 or IGF-1R subpopulation neurons did not acquire significant switch in expression phenotype after sciatic nerve axotomy. Our findings argue for an upregulation of Cav3.2 and IGF-1R expression in lumbar DRGs post-sciatic nerve axotomy and provided an insight for understanding the functions of peripheral afferent Cav3.2 channel and IGF-1/IGF-1R signaling in chronic neuropathic pain.

MeSH terms

  • Animals
  • Axotomy / adverse effects
  • Calcium Channels, T-Type / genetics
  • Calcium Channels, T-Type / metabolism*
  • Disease Models, Animal
  • Ganglia, Spinal / pathology*
  • Insulin-Like Growth Factor I / genetics
  • Insulin-Like Growth Factor I / metabolism*
  • Mice
  • Neurons / metabolism*
  • RNA, Messenger
  • Sciatic Neuropathy / pathology*

Substances

  • Cacna1h protein, mouse
  • Calcium Channels, T-Type
  • RNA, Messenger
  • insulin-like growth factor-1, mouse
  • Insulin-Like Growth Factor I