Genetically encoded calcium indicators for studying long-term calcium dynamics during apoptosis

Area of Science:

• Cell Biology
• Molecular Biology
• Biochemistry

Background:

• Intracellular calcium release regulates cellular functions and cell fate, particularly during apoptosis.
• Measuring long-term calcium dynamics is crucial for understanding apoptosis but limited by current technologies.
• Genetically encoded calcium indicators offer a potential solution to overcome limitations of calcium-sensitive dyes.

Purpose of the Study:

• To compare the performance of genetically encoded calcium indicators (GCaMP6s, GCaMP6f) with a traditional ratiometric dye (Fura-2).
• To evaluate the utility of GCaMP6s for continuous, long-term measurement of calcium dynamics during apoptosis.
• To investigate the heterogeneity of calcium release patterns in individual cells undergoing apoptosis.

Main Methods:

• Comparison of GCaMP6s and GCaMP6f performance against Fura-2 for detecting calcium transients.
• Continuous monitoring of cytosolic calcium release using GCaMP6s over ten hours post-staurosporine treatment.
• Analysis of spatio-temporal calcium dynamics in individual cells during apoptosis.

Main Results:

• GCaMP6s demonstrated performance equal to or exceeding Fura-2 in detecting agonist-induced calcium transients.
• GCaMP6s proved suitable for continuously measuring apoptotic calcium release over a ten-hour period.
• Significant heterogeneity in calcium release dynamics was observed among individual cells treated with staurosporine.

Conclusions:

• Genetically encoded calcium indicators, specifically GCaMP6s, are effective tools for long-term monitoring of intracellular calcium dynamics.
• GCaMP6s overcomes limitations of traditional dyes for studying apoptosis-related calcium signaling.
• This approach reveals crucial insights into the heterogeneity of cellular responses during programmed cell death.