Department of Exercise Science and Health Promotion, Florida Atlantic University, 777 Glades Rd, FH-11A, Rm 128-B, Boca Raton, FL, 33431, USA.
Institute for Human Health and Disease Intervention, Florida Atlantic University, Jupiter, FL, USA.
Mol Cell Biochem. 2021 Jan;476(1):23-34. doi: 10.1007/s11010-020-03882-9. Epub 2020 Aug 14.
Hepatic mitochondrial function loss is associated with cancer cachexia pathology in vivo. Here, we examined if hepatic mitochondrial defects observed in vivo in the cachexic liver also recapitulate during the in vitro treatment of mouse hepatocytes with tumor conditioned media. In vitro experiments were combined with proteome-wide expression analysis of cachexic liver tissue curated for mitochondrial dynamics and quality control proteins, to determine the fidelity of hepatic mitochondrial maladaptation in cancer cachexia pathology. AML12 hepatocytes were exposed to colon-26 (C26) and Lewis lung carcinoma (LLC) conditioned media for 6-72 h and assayed for cell viability, membrane potential, respiratory function, HO production, total ROS/RNS, and mitochondrial dynamics and quality control proteins by immunoblotting. Liver tissue from cachexic C26 mice was analyzed by TMT-based quantitative proteomics for in vivo comparison. Cell viability, membrane potential, HO production, total ROS/RNS, and respiration were decreased 48-72 h after exposure to C26 and/or LLC. Protein expression of treated hepatocytes and cachexic liver tissue showed altered mitochondrial dynamics and quality control, in a manner that suggests limited fusion and content mixing, but also impaired ability to fragment and clear damaged mitochondria. Two strategies to maintain mitochondrial health, therefore, may not be functioning sufficiently in the cachexic liver. Together these findings imply adverse effects of C26 and LLC exposure on hepatocyte health, due to impaired mitochondrial function and remodeling. Exposure of mouse hepatocytes to tumor conditioned media models aspects of cachexic liver mitochondria dysfunction in vivo and validates the importance of hepatic mitochondrial maladaptation in cancer cachexia pathology.
肝线粒体功能丧失与癌症恶病质的体内病理有关。在这里，我们研究了在恶病质肝脏中体内观察到的肝线粒体缺陷是否也在体外用肿瘤条件培养基处理小鼠肝细胞时重现。将体外实验与 curated for mitochondrial dynamics and quality control proteins 的恶病质肝组织的全蛋白质组表达分析相结合，以确定癌症恶病质病理中肝线粒体适应不良的保真度。将 AML12 肝细胞暴露于结肠-26（C26）和 Lewis 肺癌（LLC）条件培养基中 6-72 小时，并通过免疫印迹法测定细胞活力、膜电位、呼吸功能、HO 产生、总 ROS/RNS 和线粒体动力学和质量控制蛋白。通过 TMT 基于定量蛋白质组学分析恶病质 C26 小鼠的肝组织进行体内比较。暴露于 C26 和/或 LLC 48-72 小时后，细胞活力、膜电位、HO 产生、总 ROS/RNS 和呼吸作用降低。处理后的肝细胞和恶病质肝组织的蛋白质表达显示线粒体动力学和质量控制发生改变，这表明融合和内容混合有限，但也损害了碎裂和清除受损线粒体的能力。因此，两种维持线粒体健康的策略在恶病质肝脏中可能不能充分发挥作用。这些发现表明，由于线粒体功能和重塑受损，C26 和 LLC 暴露对肝细胞健康有不良影响。暴露于肿瘤条件培养基的小鼠肝细胞模型模拟了体内恶病质肝线粒体功能障碍的某些方面，并验证了肝线粒体适应不良在癌症恶病质病理中的重要性。
