Workflow and methods of high-content time-lapse analysis for quantifying intracellular calcium signals

Calcium ions (Ca²⁺) play a fundamental role in a variety of physiological functions in many cell types by acting as a secondary messenger. Variation of intracellular Ca²⁺ concentration ([Ca²⁺] _i) is often observed when the cell is stimulated. However, it is a challenging task to automatically quantify intracellular [Ca²⁺] _i in a population of cells. In this study, we present a workflow including specific algorithms for the automated intracellular calcium signal analysis using high-content, time-lapse cellular images. The experimental validations indicate the effectiveness of the proposed workflow and algorithms. We applied the workflow to analyze the intracellular calcium signals induced by different concentrations of H₂O₂ in the cell lines transfected by presenilin-1 (PS-1) that is known to be closely related to the familial Alzheimer's disease (FAD). The analysis results imply an important role of mutant PS-1, but not normal human PS-1 and mutant human amyloid precursor protein (APP), in enhancing intracellular calcium signaling induced by H ₂O₂.