A Robust Phenotypic Screening Assay Utilizing Human Podocytes to Identify Agents that Modulate Lipid Droplets.

Area of Science:

• Cell Biology
• Renal Medicine
• Drug Discovery

Background:

• Lipid droplets (LDs) are dynamic organelles involved in cell fate and are implicated as therapeutic targets in various human diseases.
• LD accumulation in podocytes leads to lipotoxicity and cell death, contributing to renal disease progression.
• Accurate assays are needed to study LDs in clinically relevant models for therapeutic development.

Purpose of the Study:

• To describe a robust phenotypic screening method for identifying small-molecule compounds that protect podocytes from LD accumulation and lipotoxicity.
• To establish an assay using differentiated human podocytes for drug screening under cellular stress.

Main Methods:

• Utilized a solvatochromic dye for improved LD staining and reduced background noise.
• Employed confocal imaging to accurately count LDs by minimizing vertical overlap.
• Combined membrane and cytoskeleton stains for enhanced cell segmentation in confocal mode.
• Implemented an optimized spot detection algorithm for reliable LD quantification.

Main Results:

• Developed a robust phenotypic screening assay for podocyte lipotoxicity.
• The assay demonstrated high accuracy and reduced background noise through advanced staining and imaging techniques.
• Achieved a consistently high Z-factor (>0.5), indicating assay robustness and reliability for screening.

Conclusions:

• The described assay is a valuable tool for identifying therapeutic compounds targeting LD accumulation in podocytes.
• This method facilitates the development of novel treatments for renal diseases associated with lipotoxicity.
• The assay's robustness and accuracy support its use in high-throughput screening for drug discovery.