Assessing Autophagic Flux by Measuring LC3, p62, and LAMP1 Co-localization Using Multispectral Imaging Flow Cytometry

Area of Science:

• Cell Biology
• Molecular Biology

Background:

• Autophagy is a fundamental cellular catabolic process for degrading and recycling cellular components via lysosomes.
• Key proteins like LC3 (microtubule-associated protein 1A/1B-light chain 1) and p62 are crucial for autophagosome formation and cargo recognition.
• Monitoring autophagic flux, the complete process from autophagosome formation to cargo degradation, is essential for understanding cellular health.

Purpose of the Study:

• To develop a more objective and statistically rigorous method for quantifying autophagy.
• To overcome limitations of traditional immunofluorescence microscopy in assessing autophagic flux.
• To enable precise measurement of LC3, p62, and lysosomal marker co-localization and LC3 puncta.

Main Methods:

• Utilized multispectral imaging flow cytometry (MIFC) for high-throughput cellular analysis.
• Developed an analytical feature within MIFC to quantify the co-localization of three key autophagy markers: LC3, p62, and LAMP1 (lysosomal-associated membrane protein 1).
• Integrated LC3 spot counting with co-localization analysis to provide a comprehensive measure of autophagic activity.

Main Results:

• MIFC enabled objective quantification of autophagy markers' co-localization.
• LC3 spot counting provided a reliable measure of autophagosome formation.
• The combined approach offered a statistically robust assessment of autophagic flux on a per-cell basis.

Conclusions:

• Multispectral imaging flow cytometry offers a powerful, quantitative, and reproducible method for studying autophagy.
• This technique overcomes the subjective limitations of manual assessment in microscopy-based autophagy studies.
• The developed analytical approach provides a robust tool for researchers investigating cellular degradation pathways.