Interlaboratory Variability in the Madin-Darby Canine Kidney Cell Proteome

Area of Science:

• Cell Biology
• Proteomics
• Pharmacology

Background:

• Madin-Darby canine kidney (MDCK) cells are crucial for studying epithelial function and drug transport.
• Variability in MDCK cell phenotypes between laboratories impacts drug permeability assessments and in vitro-in vivo extrapolation (IVIVE).

Purpose of the Study:

• To provide a comprehensive proteomic quantification of MDCK cell monolayers from multiple laboratories.
• To establish a database for understanding laboratory-to-laboratory variability in MDCK cell models.
• To enable more accurate IVIVE by characterizing control monolayers.

Main Methods:

• Proteomic quantification using the total protein approach (TPA) on 11 filter-grown MDCK monolayers from 8 different laboratories.
• Analysis of over 8000 protein copy numbers and concentrations.
• Estimation of key morphometric parameters like cellularity and volume.

Main Results:

• Identified significant laboratory-to-laboratory variability in MDCK cell phenotypes.
• Quantified expression levels of key drug transporters, with SLC16A1 (MCT1) and ABCC4 (MRP4) being the most abundant.
• Confirmed the link between claudin-2 levels and tight junction modulation affecting trans-epithelial resistance.
• MDCK cells show limited metabolic liability to xenobiotics due to low enzyme expression.

Conclusions:

• The generated proteomic database offers a valuable resource for standardizing MDCK cell models.
• Understanding MDCK cell variability is essential for reliable drug permeability studies and IVIVE.
• The data supports the use of MDCK cells as a model system, with clear characterization crucial for reproducibility.