Energy insufficiency induced by high purine diet: Catalysts for renal impairment in hyperuricemia nephropathy rat model

Abstract

A high purine diet emerges as a significant risk factor for hyperuricemia, and this diet may potentiate hyperuricemia nephropathy. Despite this, the mechanistic underpinnings of kidney damage precipitated by a high purine diet warrant further research. In the current investigation, a hyperuricemia nephropathy rat model was developed through induction via a high purine diet. Subsequently, metabolomic and proteomic analyses were employed to explore the metabolic characteristics of the kidney and shed light on the corresponding mechanistic pathway. Finally, fluorescence imaging and ¹⁸F-fluorodeoxyglucose positron emission tomography computed tomography (¹⁸F-FDG-PET/CT) were utilized to validate the overarching energy metabolism state. The results revealed extensive damage to the kidneys of hyperuricemia nephropathy rats following eight weeks of induction via a high purine diet. We used metabolomic to found that acyl carnitines and L-carnitine reduced in high purine diet group, indicated abnormal fatty acid metabolism. Irregularities were discerned in metabolites and enzymes associated with fatty acid β-oxidation, glycolysis, and oxidative phosphorylation within the kidneys of hyperuricemia nephropathy rats by proteomic and co-expression network analysis. The application of fluorescence imaging and ¹⁸F-FDG-PET/CT substantiated the inhibition of fatty acid β-oxidation and glycolysis within the kidneys of hyperuricemia nephropathy rats. On the contrary, a compensatory enhancement in the function of oxidative phosphorylation was observed. Given that the primary energy supply for renal function was derived from the metabolic pathway of fatty acids β-oxidation, any disruption within this pathway could contribute to a deficit in the energy provision to the kidneys. Such an energy insufficiency potentially laid the groundwork for eventual renal impairment. In addition, inhibition of the peroxisome proliferator-activated receptors signaling pathway was noted in the present findings, which could further exacerbate the impediment in the β-oxidation function. In conclusion, it was discerned that a deficiency in energy supply plays a critical role in the kidney injury in hyperuricemia nephropathy rats, thereby endorsing paying more attention to renal energy supply in the therapy of hyperuricemia nephropathy.