Department of Biophysics, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
PLoS One. 2012;7(8):e42522. doi: 10.1371/journal.pone.0042522. Epub 2012 Aug 8.
Several cellular mechanisms affect nuclear morphology which can therefore be used to assess certain processes. Here, we present an analytic tool to quantify the number of cells in a population that present characteristics of senescence, apoptosis or nuclear irregularities through nuclear morphometric analysis. The tool presented here is based on nuclear image analysis and evaluation of size and regularity of adhered cells in culture. From 46 measurements of nuclear morphometry, principal component analysis filtered four measurements that best separated regular from irregular nuclei. These measurements, namely aspect, area box, radius ratio and roundness were combined into a single nuclear irregularity index (NII). Normal nuclei are used to set the parameters for a given cell type, and different nuclear phenotypes are separated in an area versus NII plot. The tool was validated with β-gal staining for senescence and annexin or caspases inhibitor for apoptosis as well as several treatments that induce different cellular phenotypes. This method provides a direct and objective way of screening normal, senescent, apoptotic and nuclear irregularities which may occur during failed mitosis or mitotic catastrophe, which may be very useful in basic and clinical research.
几种细胞机制会影响核形态，因此可以用来评估某些过程。在这里，我们提出了一种分析工具，通过核形态计量分析来量化呈现衰老、凋亡或核不规则特征的细胞群体中的细胞数量。这里介绍的工具基于核图像分析和培养中贴壁细胞大小和规则性的评估。通过 46 项核形态计量测量，主成分分析筛选出了四个可最佳区分规则核和不规则核的测量值。这些测量值，即形态、面积框、半径比和圆度，被组合成一个单一的核不规则指数（NII）。正常核用于为给定的细胞类型设置参数，并且不同的核表型在面积与 NII 图中被分离。该工具已通过β-半乳糖染色（衰老的标志物）、凋亡的 Annexin 或 caspase 抑制剂以及几种诱导不同细胞表型的处理进行了验证。该方法提供了一种直接和客观的筛选正常、衰老、凋亡和核不规则的方法，这些异常可能发生在有丝分裂失败或有丝分裂灾难期间，这在基础和临床研究中可能非常有用。
