Advanced Glycation End Product Inhibitor Pyridoxamine Attenuates IVD Degeneration in Type 2 Diabetic Rats

Abstract

Type 2 diabetes mellitus (T2DM) is associated with advanced glycation end product (AGE) enrichment and considered a risk factor for intervertebral disc (IVD) degeneration. We hypothesized that systemic AGE inhibition, achieved using pyridoxamine (PM), attenuates IVD degeneration in T2DM rats. To induce IVD degeneration, lumbar disc injury or sham surgery was performed on Zucker Diabetic Sprague Dawley (ZDSD) or control Sprague Dawley (SD) rats. Post-surgery, IVD-injured ZDSD rats received daily PM dissolved in drinking water or water only. The resulting groups were SD uninjured, SD injured, ZDSD uninjured, ZDSD injured, and ZDSD injured + PM. Levels of blood glycation and disc degeneration were investigated. At week 8 post-surgery, glycated serum protein (GSP) levels were increased in ZDSDs compared to SDs. PM treatment attenuated this increase. Micro-MRI analysis demonstrated IVD dehydration in injured versus uninjured SDs and ZDSDs. In the ZDSD injured + PM group, IVD dehydration was diminished compared to ZDSD injured. AGE levels were decreased and aggrecan levels increased in ZDSD injured + PM versus ZDSD injured rats. Histological and immunohistochemical analyses further supported the beneficial effect of PM. In summary, PM attenuated GSP levels and IVD degeneration processes in ZDSD rats, demonstrating its potential to attenuate IVD degeneration in addition to managing glycemia in T2DM.