Integrated metabolic models for xenobiotic induced mitochondrial toxicity in skeletal muscle (compound 197 experiments)

There is a need for robust in vitro models to sensitively capture skeletal muscle adverse toxicities early in the research and development of novel xenobiotics. To this end, an in vitro rat skeletal muscle model (L6) was used to study the translation of transcriptomics data generated from an in vivo rat model. Novel sulfonyl isoxazoline herbicides were associated with skeletal muscle toxicity in an in vivo rat model. Gene expression pathway analysis on skeletal muscle tissues taken from in vivo repeat dose studies identified enriched pathways associated with mitochondrial dysfunction, oxidative stress, energy metabolism, protein regulation and cell cycle. Mitochondrial dysfunction and oxidative stress were further explored in an in vitro L6 model. This model demonstrated that the sulfonyl isoxazoline compounds induced mitochondrial dysfunction, mitochondrial superoxide production and apoptosis. These in vitro findings accurately concurred with the in vivo transcriptomics data, thereby confirming the ability of the L6 skeletal muscle model to identify relevant in vivo mechanisms of xenobiotic-induced toxicity. Moreover, these results highlight the sensitivity of the L6 galactose media model to study mitochondrial perturbation associated with skeletal muscle toxicity; this model may be utilised to rank the potency of novel xenobiotics upon further validation.在新型外源性化合物（xenobiotics）的研发早期阶段，亟需具备高灵敏度的体外模型，以精准捕捉骨骼肌不良毒性反应。为此，本研究采用大鼠骨骼肌体外模型（L6），探究从大鼠体内模型获取的转录组学数据的转化应用价值。新型磺酰基异恶唑啉类除草剂在大鼠体内模型中被证实可引发骨骼肌毒性。对体内重复给药研究中获取的骨骼肌组织进行基因表达通路分析后，发现了与线粒体功能障碍、氧化应激、能量代谢、蛋白质调控及细胞周期相关的富集通路。随后在L6体外模型中，针对线粒体功能障碍与氧化应激展开了深入探究。该模型证实，磺酰基异恶唑啉类化合物可诱发线粒体功能障碍、线粒体超氧化物生成以及细胞凋亡。上述体外实验结果与体内转录组学数据高度吻合，从而验证了L6骨骼肌模型能够精准识别外源性化合物诱导毒性的相关体内机制。此外，本研究结果凸显了L6半乳糖培养基模型在研究与骨骼肌毒性相关的线粒体扰动方面的灵敏度；经进一步验证后，该模型可用于对新型外源性化合物的毒性效力进行分级排序。