The BPS Art of Science Image Contest took place again this year, during the 63rd Annual Meeting in Baltimore. The image that won third place was submitted by Myung Hyun Jo, a Postdoctoral Fellow working for Taekjip Ha in the Department of Biophysics and Biophysical Chemistry, School of Medicine at Johns Hopkins University. Jo took some time to provide information about the image and the science it represents.

How did you compose this image?
Recently, molecular tension sensors have been developed to measure or control a pico-newton scale tension applied to cell membrane receptors. I used double-stranded DNA based tension sensors, which is called tension gauge tether (TGT), to monitor mechanical force through integrin receptors during cell adhesion. To measure two different levels of force instantaneously, two kinds of sensors (12 pN and 54 pN) were labeled with fluorescent dye-quencher pairs and the fluorescent signal change was analyzed. For this image, 3T3 fibroblasts were plated and incubated for three hours on a surface coated with the tension sensors. Then, I combined the analyzed time-lapse images and color-coded them according to the time elapsed (blue for early time points and red for late time points) to visualize the history of cellular force through integrins during cell adhesion. 

What do you love about this image? Or, what about this image made you submit it for the contest?
I was optimizing this method for my cell adhesion study and found that this image was a quite good summary for the dynamic cellular behavior, helping me to understand quickly what was going on. l also thought the visualizing mechanical forces would sound intriguing to many biophysicists.

What do you want viewers to see/think when they view this image?
If you look at the image closely, you can find various patterns. There are puncta, stretched and fibril-like patterns. Various adhesion structures including focal adhesions, focal complexes, and filopodia with various shapes transmit tension to the surface, and the force was recorded like a footprint. Think about the dynamic formation of adhesion structures interacting mechanically with cellular environments. We also monitored them with other imaging methods simultaneously.

How does this image reflect your scientific research?
I am interested in cell adhesion mechanism especially in mechanobiological context. This image summarizes the spatial distribution of cellular forces over time, offering insight into how adhering cells examine mechanical cues which is known to be an important step for cell differentiation and wound healing.

Can you please provide a few real-world examples of your research?
The image was taken with fibroblasts, but mechanotransduction in leukocyte activation is another important example. It is a critical step in inflammation to recruit circulating white blood cells or leukocytes in blood vessels. The leukocytes bind to the blood vessel wall and change shape in response to activation signals such as chemokines. The mechanical tension plays a key role in the leukocyte activation and molecular tension sensors are being used for these studies.

How does your research apply to those who are not working in your specific field?
Cells must respond specifically and dynamically to mechanical cues from the extracellular environment and dysregulation of extracellular force sensing leads to a variety of diseases. Therefore, it is important to deconvolve the many inputs that transduce mechanical signals and understand how these signals are interpreted and responded to.

Do you have a website where our readers can view your recent research?
I am a postdoc working with Taekjip Ha in Johns Hopkins. Please visit here for further information.