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Updated: May 27, 2025
Canine Intestinal Organoids in a Dual-Chamber Permeable Support System
Published on: March 2, 2022
Establishment of endogenous canine MUC1 knock-out MDCKII cells using CRISPR-Cas9 and evaluation of drug permeation
Hisanao Kishimoto1, Kaori Miyazaki1, Moeko Omori1
1Department of Biopharmaceutics, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1, Horinouchi, Hachioji, Tokyo, 192-0392, Japan.
Abstract:
Most orally administered drugs are absorbed by simple diffusion across the intestinal epithelium. Monolayers of MDCKII cells and parallel artificial membrane permeability assay are widely used to evaluate simple diffusion as an in vitro model; however, these models do not account for the contribution of mucus glycoprotein, which may play a significant role in drug permeation. We focused on the role of MUC1, a membrane-bound mucin that is found on the luminal surface of the gastrointestinal epithelium, in the simple diffusion of lipophilic drugs. We generated endogenous canine Mdr1 (cMdr1) and Muc1 (cMuc1) knock-out MDCKII cells by genomic editing and evaluated the effect of cMuc1 on the simple diffusion of various drugs. The absence of cMuc1 significantly increased the membrane permeation of lipophilic drugs, such as griseofulvin as well as paclitaxel and rhodamine 123, substrates of the MDR1 efflux transporter, which suggests that cMuc1 is one of the key factors that modulate the membrane permeation of these drugs. Taken together, we successfully established MDCKII cell lines with a complete knock-out of endogenous cMuc1 and cMdr1 expressions. This provides a novel in vitro model system for studying the mechanisms underlying drug absorption and transport, with potential applications for drug development.
Insights
Mucin 1 (MUC1) significantly impacts lipophilic drug absorption. Removing MUC1 from intestinal cells enhanced drug permeation, revealing its role in drug transport and offering a new model for drug development.
Area of Science:
- Pharmacology
- Cell Biology
- Biochemistry
Background:
- Oral drug absorption primarily relies on simple diffusion across the intestinal epithelium.
- Current in vitro models like MDCKII cells and PAMPA assays do not fully represent the in vivo environment, as they neglect mucus glycoprotein's role.
- Mucus glycoproteins, particularly MUC1 found on the gastrointestinal epithelium, may significantly influence drug permeation.
Purpose of the Study:
- To investigate the role of MUC1 in the simple diffusion of lipophilic drugs.
- To establish a novel in vitro model system for studying drug absorption and transport mechanisms.
Main Methods:
- Genomic editing was used to generate MDCKII cell lines with knock-out of endogenous canine Mdr1 (cMdr1) and Muc1 (cMuc1).
- The effect of cMuc1 absence on the membrane permeation of various drugs, including lipophilic compounds and MDR1 efflux transporter substrates, was evaluated.
Main Results:
- The absence of cMuc1 significantly increased the membrane permeation of lipophilic drugs like griseofulvin.
- Enhanced permeation was also observed for paclitaxel and rhodamine 123, which are substrates of the MDR1 efflux transporter.
- These findings suggest cMuc1 is a key factor modulating drug membrane permeation.
Conclusions:
- Successfully established MDCKII cell lines with complete knock-out of endogenous cMuc1 and cMdr1.
- This novel in vitro model system offers new possibilities for studying drug absorption and transport mechanisms.
- The findings have potential applications in optimizing drug development strategies.
