Role of the JAK/STAT pathway in a streptozotocin-induced diabetic retinopathy mouse model

Graefes Arch Clin Exp Ophthalmol. 2022 Nov;260(11):3553-3563. doi: 10.1007/s00417-022-05694-7. Epub 2022 May 23.

Abstract

Purpose: The Janus tyrosine kinase and signal transducers and activators of transcription (JAK/STAT) pathway is involved in vascular endothelial growth factor (VEGF) expression, but the role of this pathway in diabetic retinopathy (DR) remains unclear. We investigated the role of the JAK/STAT pathway on DR and VEGF expression using a streptozotocin (STZ)-induced DR mouse model.

Methods: Cultured ARPE-19 cells were exposed to high-glucose conditions and treated with JAK/STAT inhibitors (JAK inhibitor I [JAKiI], tofacitinib, STAT3 inhibitor [STAT3i]) for 48 h. Reverse-transcription polymerase chain reaction, western blotting, and enzyme-linked immunosorbent assay were used to investigate p-JAK/STAT and VEGF expression. Diabetes was induced by intraperitoneal injection of STZ (50 mg/kg) in C57BL/6 mice for 5 days. DR development was evaluated every 4 weeks. JAK/STAT inhibitors were administered for 8 weeks. Immunofluorescence was used to measure the activation status of the JAK/STAT pathway and VEGF production in the retinal tissue.

Results: In ARPE-19 cells exposed to high-glucose conditions, the mRNA and secretory protein levels of VEGF, p-JAK1, p-JAK2, p-STAT3, and p-STAT5 levels were significantly increased. Treatment with JAKiI, tofacitinib, and STAT3i significantly suppressed VEGF to basal levels at both the mRNA and secretory levels in vitro. In STZ-induced mice, retinal vascular leakage, p-JAK1, p-JAK2, p-JAK3, p-STAT3, and VEGF were significantly increased after diabetes induction. Diabetes-induced retinal vascular leakage was significantly reduced by treatment with JAKiI and tofacitinib. Increased p-JAK1 and VEGF in STZ-induced mice were significantly reduced by JAKiI (p < 0.05, p < 0.001) and tofacitinib (p < 0.001, respectively).

Conclusion: JAK1 may be more involved in VEGF production and DR progression in mice than JAK2, JAK3, and STAT3.

Keywords: Diabetic retinopathy; Janus tyrosine kinase; Signal transducers and activators of transcription; Vascular endothelial growth factor.

MeSH terms

  • Animals
  • Diabetes Mellitus*
  • Diabetic Retinopathy* / genetics
  • Disease Models, Animal
  • Glucose
  • Janus Kinase Inhibitors*
  • Janus Kinases
  • Mice
  • Mice, Inbred C57BL
  • Phosphorylation
  • RNA, Messenger
  • STAT Transcription Factors
  • STAT5 Transcription Factor
  • Signal Transduction / physiology
  • Streptozocin
  • Tyrosine
  • Vascular Endothelial Growth Factor A / genetics

Substances

  • Janus Kinases
  • STAT5 Transcription Factor
  • Streptozocin
  • Vascular Endothelial Growth Factor A
  • Tyrosine
  • Janus Kinase Inhibitors
  • STAT Transcription Factors
  • RNA, Messenger
  • Glucose