Malaguti C, La Guardia P G, Leite A C R, Oliveira D N, de Lima Zollner R L, Catharino R R, Vercesi A E, Oliveira H C F
Departamentos de Patologia Clínica, Universidade Estadual de Campinas , SP , Brasil.
Free Radic Res. 2014 Dec;48(12):1494-504. doi: 10.3109/10715762.2014.966706. Epub 2014 Oct 14.
Beta cell destruction in type 1 diabetes (TID) is associated with cellular oxidative stress and mitochondrial pathway of cell death. The aim of this study was to determine whether oxidative stress and mitochondrial dysfunction are present in T1D model (non-obese diabetic mouse, NOD) and if they are related to the stages of disease development. NOD mice were studied at three stages: non-diabetic, pre-diabetic, and diabetic and compared with age-matched Balb/c mice. Mitochondria respiration rates measured at phosphorylating and resting states in liver and soleus biopsies and in isolated liver mitochondria were similar in NOD and Balb/c mice at the three disease stages. However, NOD liver mitochondria were more susceptible to calcium-induced mitochondrial permeability transition as determined by cyclosporine-A-sensitive swelling and by decreased calcium retention capacity in all three stages of diabetes development. Mitochondria H2O2 production rate was higher in non-diabetic, but unaltered in pre-diabetic and diabetic NOD mice. The global cell reactive oxygen species (ROS), but not specific mitochondria ROS production, was significantly increased in NOD lymphomononuclear and stem cells in all disease stages. In addition, marked elevated rates of 2',7'-dichlorodihydrofluorescein (H2DCF) oxidation were observed in pancreatic islets from non-diabetic NOD mice. Using matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) and lipidomic approach, we identified oxidized lipid markers in NOD liver mitochondria for each disease stage, most of them being derivatives of diacylglycerols and phospholipids. These results suggest that the cellular oxidative stress precedes the establishment of diabetes and may be the cause of mitochondrial dysfunction that is involved in beta cell death.
1型糖尿病（TID）中的β细胞破坏与细胞氧化应激和细胞死亡的线粒体途径有关。本研究的目的是确定氧化应激和线粒体功能障碍是否存在于T1D模型（非肥胖糖尿病小鼠，NOD）中，以及它们是否与疾病发展阶段相关。在三个阶段研究了NOD小鼠：非糖尿病、糖尿病前期和糖尿病期，并与年龄匹配的Balb/c小鼠进行比较。在三个疾病阶段，NOD和Balb/c小鼠肝脏和比目鱼肌活检组织以及分离的肝脏线粒体中，在磷酸化和静息状态下测量的线粒体呼吸率相似。然而，通过环孢素A敏感的肿胀以及在糖尿病发展的所有三个阶段中钙保留能力的降低确定，NOD肝脏线粒体对钙诱导的线粒体通透性转变更敏感。非糖尿病NOD小鼠的线粒体H2O2产生率较高，但在糖尿病前期和糖尿病NOD小鼠中未改变。在所有疾病阶段，NOD淋巴细胞单核细胞和干细胞中的整体细胞活性氧（ROS）显著增加，但特异性线粒体ROS产生未增加。此外，在非糖尿病NOD小鼠的胰岛中观察到2',7'-二氯二氢荧光素（H2DCF）氧化率明显升高。使用基质辅助激光解吸/电离（MALDI）质谱（MS）和脂质组学方法，我们确定了每个疾病阶段NOD肝脏线粒体中的氧化脂质标志物，其中大多数是二酰基甘油和磷脂的衍生物。这些结果表明，细胞氧化应激先于糖尿病的发生，可能是参与β细胞死亡的线粒体功能障碍的原因。
