Diabetic nephropathy (DN) is a common chronic complication of diabetes, for which acute glucose fluctuation (AGF) is a potential risk factor. Fluctuating hyperglycemia has been confirmed to induce more serious kidney damage than hyperglycemia in diabetic rats; however, the mechanism remains unknown. The purpose of this study was to explore the potential role of AGF in the progression of DN. Viability of rat podocytes following 72‑h AGF treatment was detected using Cell Counting‑Kit‑8. The rates of apoptosis and the level of reactive oxygen species (ROS) in rat podocytes were assessed by flow cytometry. Western blotting and reverse transcription‑quantitative PCR were performed to measure relative protein and mRNA expression levels, respectively. Transfection with an mRFP‑GFP‑LC3 adenoviral vector was used to track autophagic flux under confocal microscopy. The results indicated that AGF could inhibit cell proliferation, promote TNF‑α, interleukin‑1β (IL‑1β), and reactive oxygen species (ROS) generation, and increase autophagy in rat podocytes. Moreover, AGF upregulated receptor for advanced glycation end products (RAGE) expression via activation of NF‑κB/p65 and IκBα. Pretreatment with 5 mM N‑Acetyl‑L‑cysteine or 10 µM pyrrolidine dithiocarbamate effectively reduced cellular damage and inhibited activation of the NF‑κB/RAGE signaling pathway. Thus, AGF induces rat podocyte injury by aggravating oxidative stress, promoting the inflammatory response, and regulating ROS‑mediated NF‑κB/RAGE activation.
Keywords: diabetes; acute glucose fluctuation; diabetic nephropathy; autophagy; RAGE; oxidative stress.