DUSP1 Attenuates Renal Injury in Diabetic Nephropathy by Modulating Ferroptosis: Evidence From Animal Experiments.

Abstract

OBJECTIVE: Emerging evidence suggests that ferroptosis contributes significantly to the progression of diabetic nephropathy (DN). This study aimed to explore the potential association between dual specificity phosphatase 1 (DUSP1) and ferroptosis in a streptozotocin-induced DN rat model. METHODS: We analyzed microarray datasets (GSE30122 and GSE96804) from the gene expression omnibus (GEO) database to identify ferroptosis-related differentially expressed genes (FDEGs), with particular focus on DUSP1. Experimental validation was performed using 45 specific pathogen-free Sprague-Dawley rats: 15 controls and 30 STZ-induced DN models (60&#x2009;mg/kg, i.p.). After 12 weeks, successfully modeled rats (n&#x2009;=&#x2009;28) were randomized into DN (n&#x2009;=&#x2009;14) and DN+Ferrostatin-1 (Fer-1, a ferroptosis inhibitor, 2.5&#x2009;&#x3bc;mol/kg, n&#x2009;=&#x2009;14) groups. Renal function parameters (blood urea nitrogen, serum creatinine, urinary albumin) were quantified using automated biochemical analysis. Renal tissue antioxidant capacity (SOD, GSH, MDA) and iron content were assessed. Histopathological evaluation employed HE, Masson, PAS, and Lillie staining. DUSP1 expression was analyzed via immunohistochemistry, Western blot, and RT-qPCR. RESULTS: DN rats exhibited characteristic metabolic disturbances including polydipsia (394.32&#x2009;&#xb1;&#x2009;9.92 vs. 28.84&#x2009;&#xb1;&#x2009;2.45&#x2009;mL/day, p&#x2009;<&#x2009;0.001), polyuria, and progressive weight loss. Renal function impairment was evidenced by elevated blood urea nitrogen (2.50&#x2009;&#xb1;&#x2009;0.46 vs. 11.61&#x2009;&#xb1;&#x2009;1.61&#x2009;mmol/L, p&#x2009;<&#x2009;0.001), serum creatinine (43.01&#x2009;&#xb1;&#x2009;5.81 vs. 107.62&#x2009;&#xb1;&#x2009;9.90&#x2009;&#x3bc;mol/L, p&#x2009;<&#x2009;0.001), and urine albumin-to-creatinine ratio (18.53&#x2009;&#xb1;&#x2009;0.92 vs. 269.97&#x2009;&#xb1;&#x2009;24.59&#x2009;mg/g, p&#x2009;<&#x2009;0.001). Fer-1 treatment significantly ameliorated these parameters (p&#x2009;<&#x2009;0.05) and reduced histopathological damage. DN rats exhibited significantly reduced DUSP1 expression and increased ferroptosis-associated alterations, including elevated ACSL4 expression, enhanced lipid peroxidation, and impaired antioxidant capacity, all of which were partially reversed by Fer-1 treatment (p&#x2009;<&#x2009;0.001). CONCLUSIONS: Our findings indicate that inhibition of ferroptosis attenuates renal injury in DN and is accompanied by altered DUSP1 expression. These results suggest a potential association between ferroptosis regulation and DUSP1 in DN, providing new insight into ferroptosis-related mechanisms involved in disease progression.