IOCBIO Sparks detection and analysis software

Abstract

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.

Prolonged β-adrenergic stimulation disperses ryanodine receptor clusters in cardiomyocytes and has implications for heart failure

“…We examined spontaneous Ca 2+ sparks since these events occur almost exclusively at dyads ( Louch et al, 2013 ), where RyR arrangements appear to be sensitive to β-AR stimulation ( Figure 1f ). Previous work has shown that acute β-AR activation increases the frequency of spontaneous Ca 2+ sparks, while diverse effects on spark geometry are reported ( Laasmaa et al, 2019 ; Tanaka et al, 1997 ; Viatchenko-Karpinski and Györke, 2001 ). We hypothesized, however, that RyR dispersion during prolonged β-AR stimulation would slow spark kinetics and increase Ca 2+ leak, as released Ca 2+ propagates between multiple clusters.…”

L-Type Cav1.3 Calcium Channels Are Required for Beta-Adrenergic Triggered Automaticity in Dormant Mouse Sinoatrial Pacemaker Cells

“…11.1). Ca 2+ transients were analyzed using ImageJ software but LCRs were analyzed using a homemade software written on R (olivierbortolotti/lcr-analysis-san (github.com), accessed on 22 November 2021), inspired by IOCBIO sparks detection and analysis software [ 32 ]. Since cells have not been permeabilized, the software measured LCR parameters after suppressing the AP-induced Ca 2+ transient to allow an accurate comparison between dormant and firing SANC.…”

Prolonged β-Adrenergic Stimulation Disperses Ryanodine Receptor Clusters in Cardiomyocytes: Implications for Heart Failure

“…1f). Previous work has shown that acute β-AR activation increases the frequency of spontaneous Ca 2+ sparks, while diverse effects on spark geometry are reported 26-28 . We hypothesized, however, that RyR dispersion during prolonged β-AR stimulation would slow spark kinetics and increase Ca 2+ leak, as released Ca 2+ propagates between multiple clusters.…”