Perforated MDCK cells support intracellular transport.

Area of Science:

• Cell Biology
• Membrane Biology
• Molecular Biology

Background:

• Intracellular transport is crucial for cellular function.
• Studying transport mechanisms often requires cell-free systems, which can be complex.
• A need exists for methods that allow direct manipulation of cellular contents while maintaining cell viability.

Purpose of the Study:

• To develop a novel method for perforating the plasma membrane of MDCK cells.
• To assess the functional integrity of perforated cells.
• To demonstrate the utility of perforated cells for studying intracellular transport.

Main Methods:

• Applying a nitrocellulose acetate filter to the apical surface of MDCK cells grown on coverslips.
• Drying the filter to adhere membrane segments, then peeling it off to create perforations.
• Utilizing light and electron microscopy to assess cell integrity.
• Tracking protein and lipid transport using radiolabeling and fluorescent probes.

Main Results:

• Perforation of the plasma membrane was achieved while maintaining cell structure and function.
• Perforated cells successfully supported vesicular transport of proteins (G protein) and lipids (sphingolipids).
• Newly synthesized proteins were correctly processed and trafficked to the trans Golgi.
• Lipid probes showed transport from the Golgi to the basolateral surface.

Conclusions:

• The developed method effectively perforates MDCK cell plasma membranes, allowing macromolecule entry.
• Perforated cells remain functional and are suitable for studying intracellular transport mechanisms.
• This technique offers a convenient and efficient alternative to cell-free assays for investigating molecular mechanisms of intracellular trafficking.