Wagoner Johnson’s sabbatical dedicated to advancements in reproductive health research

MechSE Professor Amy Wagoner Johnson has big plans for her sabbatical this calendar year, which will see her focusing on multiple efforts that aim to contribute to the evolution of women’s reproductive health research.

Within her extensive research on biomechanics, Wagoner Johnson has been investigating the impact of cervical remodeling on mechanical properties of the cervix in the context of preterm birth (listen to her recent Academic Minute regarding leveraging engineering tools to understand pregnancy and fertility here).

“My lab has been working for more than a decade to better understand the mechanics of the cervix,” she said, noting that early changes to the cervix during pregnancy can lead to preterm birth.

Traditionally, Wagoner Johnson has investigated the cervix and other tissues by using second harmonic generation imaging to look at the collagen structure within tissue slices. She also uses indentation to learn about the localized tissue stiffness in relation to the microstructure. While these processes allow the tissue sections to imaged in detail, investigating the link between microstructural changes and gene expression requires processing the tissue into a homogeneous pulp to perform a DNA analysis.

“There’s a heterogeneous structure to the tissue, meaning that in some places the collagen fibers might be aligned, while in others, they’re disorganized,” Wagoner Johnson said. “You lose that map of features when you grind up the tissue to analyze the gene expression.”

However, Wagoner Johnson is pursuing a new technology that poses an alternative means of investigating the gene expression in tissue samples while preserving their structure—spatial transcriptomics, a capability that became available at Illinois within the last couple of years.

Spatial transcriptomics allows for the point-by-point investigation of gene expression, at subcellular resolution, in a tissue sample using specially designed probes that target specific genes (i.e., thousands at a time) and label each like a bar code. These probes are then fluorescently labeled and read by the machine. This technology allows for high spatial resolution and high precision.

“With this method, we can sample from the same region both the gene expression and the microstructural changes, which allows us to make the link between structure and biology—something that we previously weren’t able to do spatially,” Wagoner Johnson said.

Wagoner Johnson was awarded a grant from the National Science Foundation’s Boosting Research Ideas for Transformative and Equitable Advances in Engineering (BRITE) program’s pivot track, which supports researchers who are seeking to incorporate new research tools to advance knowledge in their area of expertise.

During her sabbatical, Wagoner Johnson plans to learn the new technique alongside a graduate student so that it will become a practicable method in her research group. While training, she will also work closely Dr. Jenny Drnevich, Assistant Director for the HPCBio team at the Roy J. Carver Biotechnology Center.

With its precision and subcellular resolution, the cost of running spatial transcriptomics is often a barrier to entry—think ~$20k for just a few tissue samples. Wagoner Johnson’s award was the resource she needed to be able to start the initial training and gather preliminary data. With her sabbatical, she now has the other necessary ingredient—time.

“I’m really grateful that I can pursue this,” she said. “It’s an amazing opportunity.”

Separate from her new NSF grant, Wagoner Johnson also started a project with clinical imaging expert and Bioengineering affiliate Dr. Bruce Damon from the Carle Illinois Advanced Imaging Center. Damon serves as Director of Clinical Imaging at Carle’s Stephens Family Clinical Research Institute.

“We want to use magnetic resonance imaging and diffusion tensor imaging to look at cervical structure in pregnant women,” she said. “We can look at the diffusion pathway of water molecules as a proxy for the collagen organization in the cervix.”

Using this method, Wagoner Johnson and Damon would be able to excite water molecules contained in the cervix and observe their diffusion patterns. A sudden change in diffusion, which could be indicated, for example, by the pattern changing from an aligned movement in one direction to erratic movement in another, could indicate the presence of inflammation or other abnormalities in the tissue.

With these efforts, Wagoner Johnson stands to investigate cervical tissue at both micro and macro scales.

“I’m excited to go deeper into reproductive tissue mechanics and structure, and trying to link that to biology, whether it’s the biology of pregnancy in humans or the gene expression at a cellular level,” she said. “It’s a great opportunity for me to go a lot deeper in research in women’s reproductive health.”

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Amy Wagoner Johnson is an Andersen Faculty Scholar in MechSE and an investigator for Chicago’s Chan Zuckerberg BioHub. She is a member of the Carl R. Woese Institute for Genomic Biology Environmental Impacts on Reproductive Health theme and holds 0% appointments with the Grainger College of Engineering Department of Bioengineering and the Carle Illinois College of Medicine’s Departments of Biomedical and Translational Sciences and Clinical Sciences.