CNC - UC, Center for Neuroscience and Cell Biology, University of Coimbra, Portugal; CIBB - Centre for Innovative Biomedicine and Biotechnology, University of Coimbra, Portugal; PhD Programme in Experimental Biology and Biomedicine (PDBEB), Institute for Interdisciplinary Research (IIIUC), University of Coimbra, Portugal.
CNC - UC, Center for Neuroscience and Cell Biology, University of Coimbra, Portugal; CIBB - Centre for Innovative Biomedicine and Biotechnology, University of Coimbra, Portugal.
Biochim Biophys Acta Mol Basis Dis. 2025 Jan;1871(1):167495. doi: 10.1016/j.bbadis.2024.167495. Epub 2024 Sep 4.
Aging and lifestyle-related diseases, such as cardiovascular diseases, diabetes, cancer, and neurodegenerative disorders, are major global health challenges. These conditions are often linked to redox imbalances, where cells fail to regulate reactive redox species (RRS), leading to oxidative stress and cellular damage. Although antioxidants are known to neutralize harmful RRS, their clinical efficacy remains inconsistent. One reason for this inconsistency is the inadequacy of current in vitro models to accurately mimic in vivo redox conditions. This study addresses the gap in understanding the heterogeneity of redox responses in cells by using metabolically primed human dermal fibroblasts (NHDF), a model relevant for precision mitochondrial medicine. We investigated how metabolic priming, which enhances mitochondrial bioenergetics, influences redox responses to oxidative stress induced by hydrogen peroxide (HO) and tert-butyl hydroperoxide (tBHP). Specifically, we explored the impact of cell population density and cell cycle distribution on redox dynamics. Our findings indicate that NHDF cells cultured in oxidative phosphorylation-promoting medium (OXm) exhibit significantly larger variability in oxidative stress responses. This variability suggests that enhanced mitochondrial bioenergetics necessitates a constant regulation of the cellular redox machinery, potentially leading to heterogeneous responses. Additionally, cells grown in OXm showed increased mitochondrial polarization and a lower percentage of cells in the G2/M phase, contributing to the observed heterogeneity. Key factors influencing this variability included cell population density at the time of oxidant exposure and fluctuations in cell cycle distribution. Our results highlight the necessity of employing multiple oxidants in metabolic priming models to achieve a comprehensive understanding of oxidative stress responses and redox regulation mechanisms. Furthermore, the study emphasizes the need to refine in vitro models to better reflect in vivo conditions, which is crucial for the development of effective redox-based therapeutic strategies.
衰老和与生活方式相关的疾病，如心血管疾病、糖尿病、癌症和神经退行性疾病，是全球主要的健康挑战。这些疾病通常与氧化还原失衡有关，即细胞无法调节活性氧化还原物质（RRS），导致氧化应激和细胞损伤。尽管抗氧化剂被认为可以中和有害的 RRS，但它们的临床疗效仍然不一致。造成这种不一致的一个原因是，目前的体外模型不足以准确模拟体内氧化还原条件。本研究通过使用代谢激活的人真皮成纤维细胞（NHDF）解决了理解细胞氧化还原反应异质性的理解差距，这是一种与精准线粒体医学相关的模型。我们研究了代谢激活（增强线粒体生物能学）如何影响过氧化氢（HO）和叔丁基过氧化物（tBHP）诱导的氧化应激的氧化还原反应。具体来说，我们探讨了细胞群体密度和细胞周期分布对氧化还原动力学的影响。我们的研究结果表明，在促进氧化磷酸化的培养基（OXm）中培养的 NHDF 细胞对氧化应激反应的变异性更大。这种变异性表明，增强的线粒体生物能学需要不断调节细胞的氧化还原机制，可能导致异质性反应。此外，在 OXm 中生长的细胞显示出更高的线粒体极化和更低比例的细胞处于 G2/M 期，这有助于观察到的异质性。影响这种变异性的关键因素包括暴露于氧化剂时的细胞群体密度和细胞周期分布的波动。我们的研究结果强调了在代谢激活模型中使用多种氧化剂的必要性，以全面了解氧化应激反应和氧化还原调节机制。此外，该研究强调需要改进体外模型，以更好地反映体内条件，这对于开发有效的基于氧化还原的治疗策略至关重要。
