Bioscience Metabolism, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden.
Bioscience Metabolism, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden; The Lundberg Laboratory for Diabetes Research, University of Gothenburg, Gothenburg, Sweden; Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Gothenburg, Sweden.
J Lipid Res. 2022 Mar;63(3):100176. doi: 10.1016/j.jlr.2022.100176. Epub 2022 Feb 2.
Sodium-glucose cotransporter 2 (SGLT2) inhibitors have been shown to increase ketone bodies in patients with type 2 diabetes; however, the underlying mechanisms have not been fully elucidated. Here we examined the effect of the SGLT2 inhibitor dapagliflozin (1 mg/kg/day, formulated in a water, PEG400, ethanol, propylene glycol solution, 4 weeks) on lipid metabolism in obese Zucker rats. Fasting FFA metabolism was assessed in the anesthetized state using a [9,10-H(N)]-palmitic acid tracer by estimating rates of plasma FFA appearance (R), whole-body FFA oxidation (R), and nonoxidative disposal (R). In the liver, clearance (K) and flux (R) of FFA into β-oxidation were estimated using [9,10-H]-(R)-bromopalmitate/[U-C]palmitate tracers. As expected, dapagliflozin induced glycosuria and a robust antidiabetic effect; treatment reduced fasting plasma glucose and insulin, lowered glycated hemoglobin, and increased pancreatic insulin content compared with vehicle controls. Dapagliflozin also increased plasma FFA, R, R, and R with enhanced channeling toward oxidation versus storage. In the liver, there was also enhanced channeling of FFA to β-oxidation, with increased K, R and tissue acetyl-CoA, compared with controls. Finally, dapagliflozin increased hepatic HMG-CoA and plasma β-hydroxybutyrate, consistent with a specific enhancement of ketogenesis. Since ketogenesis has not been directly measured, we cannot exclude an additional contribution of impaired ketone body clearance to the ketosis. In conclusion, this study provides evidence that the dapagliflozin-induced increase in plasma ketone bodies is driven by the combined action of FFA mobilization from adipose tissue and diversion of hepatic FFA toward β-oxidation.
钠-葡萄糖共转运蛋白 2(SGLT2)抑制剂已被证明可增加 2 型糖尿病患者的酮体;然而,其潜在机制尚未完全阐明。在这里,我们研究了 SGLT2 抑制剂达格列净(1mg/kg/天,溶于水、PEG400、乙醇、丙二醇溶液中,4 周)对肥胖 Zucker 大鼠脂质代谢的影响。在麻醉状态下,使用[9,10-H(N)]-棕榈酸示踪剂评估空腹游离脂肪酸(FFA)代谢,通过估计血浆 FFA 出现率(R)、全身 FFA 氧化率(R)和非氧化处置率(R)来评估。在肝脏中,使用[9,10-H]-(R)-溴代棕榈酸/[U-C]棕榈酸示踪剂估计 FFA 进入β-氧化的清除率(K)和通量(R)。如预期的那样,达格列净诱导糖尿并产生强大的抗糖尿病作用;与载体对照相比,治疗降低了空腹血糖和胰岛素,降低了糖化血红蛋白,并增加了胰腺胰岛素含量。达格列净还增加了血浆 FFA、R、R 和 R,与储存相比,更多地促进了氧化而非储存。在肝脏中,与对照组相比,FFA 向β-氧化的通道也增加了,K、R 和组织乙酰辅酶 A 增加。最后,达格列净增加了肝 HMG-CoA 和血浆β-羟丁酸,这与酮生成的特异性增强一致。由于尚未直接测量酮生成,我们不能排除酮体清除受损对酮症的额外贡献。总之,这项研究提供了证据表明,达格列净诱导的血浆酮体增加是由脂肪组织中 FFA 的动员和肝脏 FFA 向β-氧化的转移的联合作用驱动的。