Laasmaa Martin, Karro Niina, Birkedal Rikke, Vendelin Marko
Laboratory of Systems Biology, Department of Cybernetics, School of Science, Tallinn University of Technology, Tallinn, Estonia.
PeerJ. 2019 Mar 29;7:e6652. doi: 10.7717/peerj.6652. eCollection 2019.
Analysis of calcium sparks in cardiomyocytes can provide valuable information about functional changes of calcium handling in health and disease. As a part of the calcium sparks analysis, sparks detection and characterization is necessary. Here, we describe a new open-source platform for automatic calcium sparks detection from line scan confocal images. The developed software is tailored for detecting only calcium sparks, allowing us to design a graphical user interface specifically for this task. The software enables detecting sparks automatically as well as adding, removing, or adjusting regions of interest marking each spark. The results of the analysis are stored in an SQL database, allowing simple integration with statistical tools. We have analyzed the performance of the algorithm using a large set of synthetic images with varying spark sizes and noise levels and also compared the analysis results with results obtained by software established in the field. The use of our software is illustrated by an analysis of the effect of isoprenaline (ISO) on spark frequency, amplitude, and spatial and temporal characteristics. For that, cardiomyocytes from C57BL/6 mice were used. We demonstrated an increase in spark frequency, tendency of having larger spark amplitudes, sparks with a longer duration, and occurrence of multiple sparks from the same site in the presence of ISO. We also show that the duration and the width of sparks with the same amplitude were similar in the absence and presence of ISO. The software was released as an open source repository and is available for free use and collaborative development.
分析心肌细胞中的钙火花可提供有关健康和疾病状态下钙处理功能变化的有价值信息。作为钙火花分析的一部分,火花检测和特征描述是必要的。在此,我们描述了一个用于从线扫描共聚焦图像中自动检测钙火花的新开源平台。所开发的软件专门用于仅检测钙火花,这使我们能够设计一个专门针对此任务的图形用户界面。该软件能够自动检测火花,并添加、移除或调整标记每个火花的感兴趣区域。分析结果存储在SQL数据库中,便于与统计工具简单集成。我们使用了大量具有不同火花大小和噪声水平的合成图像分析了该算法的性能,并将分析结果与该领域已有的软件所获得的结果进行了比较。通过分析异丙肾上腺素(ISO)对火花频率、幅度以及空间和时间特征的影响来说明我们软件的使用。为此,使用了C57BL/6小鼠的心肌细胞。我们证明了在存在ISO的情况下,火花频率增加,火花幅度有变大的趋势,火花持续时间更长,并且同一位置出现多个火花。我们还表明,在不存在和存在ISO的情况下,相同幅度的火花的持续时间和宽度相似。该软件作为开源存储库发布,可免费使用并用于协作开发。