Impact of SGLT2 inhibitor dapagliflozin on myocardial protein profile in rats with long-standing Type 1 diabetes mellitus

Abstract Background Sodium-glucose cotransporter 2 (SGLT2) inhibitors have beneficial effects on the cardiovascular system in diabetes mellitus (DM) patients. However, as most trials have focused on Type 2 DM, the impact of SGLT2 inhibitors on Type 1 DM remains unclear. Objective To investigate the effects of long-term treatment with SGLT2 inhibitor dapagliflozin on the left ventricular (LV) proteome in Type 1 DM rats. Methods Male Wistar rats were divided into three groups: Control (C, n=7); Diabetes (DM, n=6); and Diabetes treated with Dapagliflozin (DM+DAPA, n=8) for 30 weeks. Diabetes was induced by streptozotocin (40 mg/kg). Dapagliflozin was added to chow at 5 mg/kg/day. Label-free mass spectrometry was used to assess LV proteome using a nanoAcquity UPLC-Xevo QTof MS system and ProteinLynx Global Server (PLGS) software. Cytoscape software, Cluster Marker, and Cluego plugins were used for bioinformatic analysis. Statistical analysis: ANOVA and Tukey or Kruskal-Wallis and Dunn. Results Dapagliflozin increased body weight (C 574±43; DM 339±31*; DM+DAPA 413±30*# g; p<0.05: * vs C; # vs DM) and reduced glycemia [C 108 (101–111); DM 554 (529–562)*; DM+DAPA 343 (237–416)*# mg/dL; p<0.05: * vs C; # vs DM]. One rat died in C and two in DM+DAPA. A total of 252 differentially expressed proteins were identified. Most proteins identified in the networks were downregulated in DM vs C and upregulated in DM+DAPA vs DM. Six proteins related to energy metabolism (Atp5j, P21571; CKm, P00564; Ak1, P39069; Atp5h, P31399; Mdh1, O88989; and Idh2, P56574), four involved in myocyte excitation-contraction (Act1, P68065; Casq2, P51868; SERCA1, Q64578; and SERCA2a, P11507), and two associated with oxidative stress (Sod1, P07632; and Sod2, P07895) were upregulated in DM+DAPA x DM. Comparing DM with C, the KEEG Pathway with the highest percentage of gene associations for upregulated proteins was related to gap junction (25.6%), necroptosis (25.6%), and fatty acid degradation (25.6%), and for downregulated proteins was related to Alzheimer disease (27.3%), cardiac muscle contraction (25%) and glycolysis/gluconeogenesis (13.6%). Comparing DM+DAPA with DM, the KEEG Pathway with the highest percentage of gene associations for upregulated proteins was related to Parkinson disease (18.3%), cardiac muscle contraction (14.2%), citrate acid cycle (9.47%), necroptosis (8.88%), and cGMP-PKG signaling (7.10 %), and for downregulated proteins was related to ketone bodies synthesis and degradation (100%). Conclusion Dapagliflozin is safe and prevents changes in the expression of proteins related to energy metabolism, cardiac muscle contraction, and oxidative stress in Type 1 diabetes mellitus rats. These results offer new insights into the cardioprotective mechanisms of dapagliflozin in Type 1 diabetes mellitus.