Cells 'feel' the difference between stiff or soft and thick or thin matrix

Dec 13, 2010

Cultured mesenchymal stem cells can "feel" at least several microns below the surface of an artificial microfilm matrix, gauging the elasticity of the extracellular bedding that is a crucial variable in determining their fate, researchers reported today at the American Society for Cell Biology's 50th Annual Meeting in Philadelphia.

Controlling or predicting how stem cells differentiate into cells of a specific tissue type is a critical issue in the of artificial tissue and in stem cell medicine.

To determine how deep a cell's sense of touch can reach, University of Pennsylvania researchers placed naive (MSCs) on microfilm matrices controlled for thickness and elasticity and bonded to rigid glass.

Amnon Buxboim, Ph.D., of the University of Pennsylvania and colleagues constructed these artificial bedding surfaces to mimic the extracellular matrix that stem cells "feel" as they differentiate.

They used naive MSCs as prototypical adherent cells, because they are particularly sensitive to micro-environmental factors such as elasticity or hardness as they differentiate.

By a variety of measures, the researchers concluded that MSCs can "feel" to several microns into compliant matrices. The stiffer the surface, the shallower the cells could feel; the softer the surface, the deeper they could "feel."

Because the matrices varied, the scientists were able to document significant differences between stem cells grown on varying stiffness and thickness that represent human tissue microenvironments ⎯ such as brain tissue, which is softer than muscle, which is softer than cartilage, which is softer than pre-calcified bone.

In previous studies, the researchers discovered that as tissue cells adhered to a soft natural , they pulled and deformed the surface, actions that allowed the cells to use their sense of touch below the surface.

To determine how the thickness and stiffness of the microfilm affected the form of cells grown on top, they deployed a range of methods to document significant differences between grown on thin films versus thick films.

Cell shape was measured by confocal microscopy and micro-elasticity by atomic force microscopy. Cellular responses were analyzed in terms of morphology while cytoskeletal organization was mapped using non-muscle myosin assembly. Changes in gene expression were obtained by DNA microarray-based transcriptional analysis of the genome.

Explore further: Researchers discover new mechanism of DNA repair

Related Stories

Physical environment influences stem cell development

Sep 07, 2010

A researcher at the Hebrew University of Jerusalem, together with Israeli and foreign collaborators, has revealed how physical qualities -- and not only chemical ones - may have an influence in determining how adult stem ...

Recommended for you

Researchers discover new mechanism of DNA repair

Jul 03, 2015

The DNA molecule is chemically unstable giving rise to DNA lesions of different nature. That is why DNA damage detection, signaling and repair, collectively known as the DNA damage response, are needed.

Stopping Candida in its tracks

Jul 03, 2015

Scientists are one step closer to understanding how a normally harmless fungus changes to become a deadly infectious agent.

New technique maps elusive chemical markers on proteins

Jul 02, 2015

Unveiling how the 20,000 or so proteins in the human body work—and malfunction—is the key to understanding much of health and disease. Now, Salk researchers developed a new technique that allows scientists ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.