The role of G-protein-coupled receptor kinase 2 in diabetic mechanical hyperalgesia in rats

Eur J Pain. 2021 Oct;25(9):2039-2049. doi: 10.1002/ejp.1819. Epub 2021 Jul 3.

Abstract

Background: Previous studies have indicated a negative correlation between GRK2 expression and pain development and transmission. Here, we investigated whether G-protein-coupled receptor kinase 2 (GRK2) was involved in regulating diabetic mechanical hyperalgesia (DMH).

Methods: The adeno-associated viral vectors containing the GRK2 gene (AAV-GRK2) were used to up-regulate GRK2 protein expression. The expression of GRK2 and exchange protein directly activated by cyclic adenosine monophosphate 1 (Epac1) in the dorsal root ganglion (DRG) of lumbar 4-6 was detected via immunoblotting and immunohistochemistry, and the transfection of the GRK2 gene was detected by immunofluorescence.

Results: Low levels of GRK2 were able to sustain STZ-induced pain in DMH rats. Intrathecal injection of AAV-GRK2 vector up-regulated GRK2 expression, providing pain rain to rats with DMH. With an increase in DMH duration, there was a decrease in paw withdrawal threshold (PWT) value, aggravating the pain, resulting in a decreasing pattern in GRK2 protein expression over time, whereas Epac1 protein expression showed an opposite trend.

Conclusion: GRK2 expression regulated DMH progression and is expected to play a role in the development of targeted therapy for DMH. GRK2 and Epac1 expressions play a vital role in maintaining pain in DMH rats.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Diabetes Mellitus*
  • G-Protein-Coupled Receptor Kinase 2 / genetics
  • Ganglia, Spinal
  • Hyperalgesia* / genetics
  • Pain
  • Rats

Substances

  • Grk2 protein, rat
  • G-Protein-Coupled Receptor Kinase 2