Nogo-B Promotes Angiogenesis in Proliferative Diabetic Retinopathy via VEGF/PI3K/Akt Pathway in an Autocrine Manner

Cell Physiol Biochem. 2017;43(5):1742-1754. doi: 10.1159/000484061. Epub 2017 Oct 19.

Abstract

Background/aims: Nogo-B, a conservative protein of endoplasmic reticulum, is a member of the reticulon family of proteins. Proliferative diabetic retinopathy (PDR) is the major concerning problem of diabetic retinopathy. This study explored the role of Nogo-B in the regulation of angiogenesis in PDR patients and primary human retinal endothelial cells (HRMECs).

Methods: Nogo-B was down-regulated through the use of Lentivirus-NogoB-RNAi, the effects of Nogo-B on angiogenesis under high glucose stimulation were evaluated via CCK-8 assay, wound closure assay, transwell assay, and tube formation assay. Expression of Nogo-B, VEGF, PI3K and Akt were determined by western blotting, immunofluorescence, enzyme-linked immunosorbent assay (ELISA). Co-culture systerm was used to explore cell communication.

Results: Nogo-B was highly enriched in ocular tissues of PDR patients and in HRMECs exposed to high glucose. Down-regulation of Nogo-B attenuated high glucose induced cell migration and tube formation in HRMECs. Mechanistically, in comparison with the negative control group, Lentivirus-NogoB-RNAi group had exhibited reduced VEGF secretion, weakened PI3K and Akt activation. Besides, high glucose treatment promoted the secretion of Nogo-B and presented as a "long-term memory".

Conclusions: These data collectively indicated that Nogo-B promoted angiogenesis in HRMECs via VEGF/PI3K/Akt pathway in an autocrine manner.

Keywords: Angiogenesis; Nogo-B; Proliferative diabetic retinopathy.

MeSH terms

  • Blotting, Western
  • Cells, Cultured
  • Diabetic Retinopathy / metabolism*
  • Endothelial Cells / drug effects*
  • Endothelial Cells / metabolism*
  • Enzyme-Linked Immunosorbent Assay
  • Fluorescent Antibody Technique
  • Glucose / pharmacology
  • Humans
  • Immunohistochemistry
  • In Vitro Techniques
  • Nogo Proteins / genetics
  • Nogo Proteins / metabolism*
  • Phosphatidylinositol 3-Kinases / metabolism*
  • Proto-Oncogene Proteins c-akt / metabolism*
  • RNA Interference
  • Retina
  • Signal Transduction / drug effects
  • Signal Transduction / genetics
  • Vascular Endothelial Growth Factor A / metabolism*

Substances

  • Nogo Proteins
  • Vascular Endothelial Growth Factor A
  • Phosphatidylinositol 3-Kinases
  • Proto-Oncogene Proteins c-akt
  • Glucose