Spano Alessandra, Sciola Luigi
Department of Biomedical Sciences, University of Sassari, Via Muroni 25, I-07100 Sassari, Italy.
Cells. 2025 Aug 16;14(16):1268. doi: 10.3390/cells14161268.
Cellular senescence can occur with similar phenotypes in normal cells, during aging, and in tumor cells, spontaneously or after cytostasis. The fall or increase in proliferative activity are key aspects of the respective conditions, in which the levels of reactive oxygen species can vary, affecting the cellular redox homeostasis. This work aimed to study the relationships between senescence and transformation by comparing cells with different proliferative activities and phenotypes attributable to transformation (NIHs cultures) or senescence (NIHv cultures), before and after incubation with hydrogen peroxide. Both cultures were derived from the NIH/3T3 cell line, which was used here as a reference (NIHb), after the serum starvation. Our experimental model can be representative of the heterogeneity of cell subpopulations, with different degrees of transformation and senescence, found in some tumors. The characterization of the functional properties of NIHb, NIHs, and NIHv cells was performed by a morphocytometric analysis of the cell cycle progression, mitochondrial and lysosomal content/activity, and superoxide anion production. The efficiency of the lysosomal compartment was also assessed by estimating the autophagic activity and measuring lipofuscin autofluorescence. Comparisons of nuclear and cytoplasmic parameters before and after the incubation with hydrogen peroxide revealed differences in the expression and modulation of cellular senescence patterns. The treatment effects were very limited in the NIHb culture; the senescence condition was essentially maintained in the NIHv cells, while the most relevant changes were found in the NIHs cells. In the latter, the acquisition of the senescent phenotype, also demonstrated by the positivity of SA-β-galactosidase, was correlated with a decrease in proliferative activity and a change in the content/activity of the mitochondria and lysosomes, which showed similarities with the basal senescence conditions of NIHv cells. In NIHs cells, increased autophagy events and lipofuscin accumulation also indicate the establishment of cytoplasmic dynamics typical of senescence. The variable responses to hydrogen peroxide, besides depending on the different basal cytokinetic activity of the cultures examined, appeared to be related to the specific cell redox state resulting from the balance between endogenous ROS and those produced after treatment. Especially in NIHs cells, the slowing down of the cell cycle was linked to dynamic interconnections between the mitochondrial and lysosomal compartments. This would indicate that transformed cells, such as NIHs, may express morpho-functional aspects and markers typical of cellular senescence, as a consequence of the modulation of their redox state.
细胞衰老可在正常细胞、衰老过程以及肿瘤细胞中以相似的表型出现，可自发发生或在细胞生长停滞之后发生。增殖活性的下降或增加是各自情况的关键方面，其中活性氧水平可能会有所不同，从而影响细胞的氧化还原稳态。这项工作旨在通过比较具有不同增殖活性以及归因于转化（NIHs培养物）或衰老（NIHv培养物）的表型的细胞，研究衰老与转化之间的关系，这些细胞在与过氧化氢孵育之前和之后进行比较。两种培养物均源自NIH/3T3细胞系，血清饥饿后在此用作对照（NIHb）。我们的实验模型可以代表在一些肿瘤中发现的具有不同转化和衰老程度的细胞亚群的异质性。通过对细胞周期进程、线粒体和溶酶体含量/活性以及超氧阴离子产生进行形态细胞计量分析，对NIHb、NIHs和NIHv细胞的功能特性进行了表征。还通过估计自噬活性和测量脂褐素自发荧光来评估溶酶体区室的效率。比较过氧化氢孵育前后的细胞核和细胞质参数，揭示了细胞衰老模式的表达和调节存在差异。在NIHb培养物中，处理效果非常有限；在NIHv细胞中衰老状态基本维持，而在NIHs细胞中发现了最相关的变化。在后者中，衰老表型的获得（也通过SA-β-半乳糖苷酶的阳性得以证明）与增殖活性的降低以及线粒体和溶酶体的含量/活性变化相关，这与NIHv细胞的基础衰老状态相似。在NIHs细胞中，自噬事件增加和脂褐素积累也表明建立了衰老典型的细胞质动态变化。对过氧化氢的不同反应，除了取决于所检测培养物不同的基础细胞动力学活性外，似乎还与内源性ROS与处理后产生的ROS之间平衡所导致的特定细胞氧化还原状态有关。特别是在NIHs细胞中，细胞周期的减慢与线粒体和溶酶体区室之间的动态相互联系有关。这表明转化细胞，如NIHs，可能由于其氧化还原状态的调节而表现出细胞衰老典型的形态功能方面和标志物。
