Nogo-B Promotes Endoplasmic Reticulum Stress-Mediated Autophagy in Endothelial Cells of Diabetic Nephropathy.

Aims: Endothelial cells are the critical targets of injury in diabetic nephropathy (DN), and endothelial cell lesions contribute to the disease progression. Neurite outgrowth inhibitor B (Nogo-B), an endoplasmic reticulum (ER)-resident protein, plays a pivotal role in vascular remodeling after injury, and maintains the structure and function of the ER. Yet, the role of Nogo-B in the regulation of ER stress and endothelial cell injury remains largely unknown. Herein, we tested the hypothesis that Nogo-B activates ER stress-mediated autophagy and protects endothelial cells in DN. Results: The level of Nogo-B was decreased in glomerular endothelial cells in biopsy specimens from DN patients. In vivo and in vitro studies have shown that silencing Nogo-B activated ER stress signaling, and affected the expression of autophagy-related marker early growth response 1 and microtubule-associated protein light chain 3 (LC3) in endothelial cells in hyperglycemic condition. Conclusion and Innovation: These results denote that Nogo-B contributes to ER stress-mediated autophagy and protects endothelial cells in DN, providing new evidence for understanding the role of ER stress-mediated autophagy in endothelial cells of DN.