ABSTRACT

The diabetes medication canagliflozin (Cana) is a sodium glucose cotransporter 2 (SGLT2) inhibitor acting by increasing urinary glucose excretion and thus reducing hyperglycaemia. Cana treatment also reduces body weight. However, it remains unclear whether Cana could directly work on adipose tissue. In the present study, the pharmacological effects of Cana and the associated mechanism were investigated in adipocytes and mice. Stromal-vascular fractions (SVFs) were isolated from subcutaneous adipose tissue and differentiated into mature adipocytes. Our results show that Cana treatment directly increased cellular energy expenditure of adipocytes by inducing mitochondrial biogenesis independently of SGLT2 inhibition. Along with mitochondrial biogenesis, Cana also increased mitochondrial oxidative phosphorylation, fatty acid oxidation and thermogenesis. Mechanistically, Cana promoted mitochondrial biogenesis and function via an Adenosine monophosphate-activated protein kinase (AMPK) – silent information regulator 1 (Sirt1) – peroxisome proliferator-activated receptor γ coactivator-1α (Pgc-1α) signalling pathway. Consistently, in vivo study demonstrated that Cana increased AMPK phosphorylation and the expression of Sirt1 and Pgc-1α. The present study reveals a new therapeutic function for Cana in regulating energy homoeostasis.

Abbreviations

Ucp-1, uncoupling protein 1; cAMP, cyclic adenosine monophosphate; PKA, cAMP-dependent protein kinase A; SGLT, sodium glucose cotransporter; Cana, canagliflozin; T2DM: type 2 diabetes; Veh, vehicle; Pgc-1α, peroxisome proliferator-activated receptor γ coactivator-1α; SVFs, stromal-vascular fractions; FBS, bovine serum; Ad, adenovirus; mtDNA, mitochondrial DNA; COX2, cytochrome oxidase subunit 2; RT-PCR, real-time PCR; SDS-PAGE, sodium dodecyl sulphate-polyacrylamide gel electrophoresis; Prdm16, PR domain zinc finger protein 16; Cidea, cell death inducing DFFA-like effector A; Pgc-1β, peroxisome proliferator-activated receptor γ coactivator-1β; NRF1, nuclear respiratory factor 1; Tfam, mitochondrial transcription factor A; OXPHOS, oxidative phosphorylation; FAO, fatty acid oxidation; AMPK, Adenosine monophosphate-activated protein kinase; p-AMPK, phosphorylated AMPK; Sirt1, silent information regulator 1; mTOR, mammalian target of rapamycin; WAT, white adipose tissue; Fabp4, fatty acid binding protein 4; Lpl, lipoprotein lipase; Slc5a2, solute carrier family 5 member 2; ERRα, oestrogen related receptor α; Uqcrc2, ubiquinol-cytochrome c reductase core protein 2; Uqcrfs1, ubiquinol-cytochrome c reductase, Rieske iron-sulphur polypeptide 1; Cox4, cytochrome c oxidase subunit 4; Pparα, peroxisome proliferator activated receptor α; NAD⁺, nicotinamide adenine dinucleotide; Dio2, iodothyronine deiodinase 2; Tmem26, transmembrane protein 26; Hoxa9, homeobox A9; FCCP, carbonyl cyanide 4-(trifluoromethoxy) phenylhydrazone; Rot/AA, rotenone/antimycin A; OCR, oxygen consumption rate; Pparγ, peroxisome proliferator activated receptor γ; C/ebp, CCAAT/enhancer binding protein; LKB1, liver kinase B1; AUC, area under the cure; Vd, apparent volume of distribution.

中文翻译：

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糖尿病药物Canagliflozin通过AMPK-Sirt1-Pgc-1α信号通路促进脂肪细胞的线粒体重塑。

摘要

糖尿病药物canagliflozin（Cana）是一种钠葡萄糖共转运蛋白2（SGLT2）抑制剂，可通过增加尿中葡萄糖的排泄从而减少高血糖而发挥作用。Cana治疗还可以减轻体重。但是，尚不清楚Cana是否可以直接作用于脂肪组织。在本研究中，研究了Cana在脂肪细胞和小鼠中的药理作用及其相关机制。从皮下脂肪组织中分离出基质血管部分（SVF），并分化为成熟的脂肪细胞。我们的结果表明，Cana治疗通过诱导线粒体生物发生而独立于SGLT2抑制作用而直接增加了脂肪细胞的细胞能量消耗。除了线粒体生物发生以外，Cana还增加了线粒体的氧化磷酸化作用，脂肪酸氧化和生热。机械上，Cana通过单磷酸腺苷激活的蛋白激酶（AMPK）–沉默信息调节剂1（Sirt1）–过氧化物酶体增殖物激活的受体γcoactivator-1α（Pgc-1α）信号传导途径来促进线粒体的生物发生和功能。一致地，体内研究表明，Cana可增加AMPK磷酸化以及Sirt1和Pgc-1α的表达。本研究揭示了Cana在调节能量稳态方面的新治疗功能。

缩略语

Ucp-1，解偶联蛋白1；cAMP，环状单磷酸腺苷；PKA，cAMP依赖性蛋白激酶A；SGLT，钠葡萄糖共转运蛋白；Cana，canagliflozin; T2DM：2型糖尿病；车辆 Pgc-1α，过氧化物酶体增殖物激活受体γcoactivator-1α；SVF，基质血管部分；FBS，牛血清；Ad，腺病毒；mtDNA，线粒体DNA；COX2，细胞色素氧化酶亚基2；RT-PCR，实时PCR SDS-PAGE，十二烷基硫酸钠-聚丙烯酰胺凝胶电泳；Prdm16，PR结构域锌指蛋白16；Cidea，诱导细胞死亡的类DFFA效应子A；Pgc-1β，过氧化物酶体增殖物激活受体γ共激活因子-1β；NRF1，核呼吸因子1；Tfam，线粒体转录因子A；OXPHOS，氧化磷酸化；粮农组织，脂肪酸氧化；AMPK，单磷酸腺苷激活的蛋白激酶；p-AMPK，磷酸化的AMPK; Sirt1，静默信息调节器1；mTOR，雷帕霉素的哺乳动物靶标；WAT，白色脂肪组织；Fabp4，脂肪酸结合蛋白4；Lpl，脂蛋白脂肪酶；Slc5a2，溶质载体家族5成员2；ERRα，雌激素相关受体α；Uqcrc2，泛醇-细胞色素c还原酶核心蛋白2；Uqcrfs1，泛醇-细胞色素c还原酶，Rieske铁-硫多肽1；Cox4，细胞色素c氧化酶亚基4；Pparα，过氧化物酶体增殖物激活受体α；NAD Rieske铁-硫多肽1; Cox4，细胞色素c氧化酶亚基4；Pparα，过氧化物酶体增殖物激活受体α；NAD Rieske铁-硫多肽1; Cox4，细胞色素c氧化酶亚基4；Pparα，过氧化物酶体增殖物激活受体α；NAD⁺，烟酰胺腺嘌呤二核苷酸；Dio2，碘甲状腺素脱碘酶2；Tmem26，跨膜蛋白26；Hoxa9，homeobox A9；FCCP，羰基氰化物4-（三氟甲氧基）苯hydr；腐烂/ AA，鱼藤酮/抗霉素A；OCR，耗氧率；Pparγ，过氧化物酶体增殖物激活受体γ；C / ebp，CCAAT /增强子结合蛋白；LKB1，肝激酶B1；AUC，治疗范围；Vd，表观分布量。