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College of Engineering Department of Biomedical Engineering

SPRING/SUMMER 2002

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Faculty profile: Naomi Chesler

Faculty news

Faculty profile: Naomi Chesler

Research in "vein"

Naomi  Chesler

Naomi Chesler (12K JPG)

Understanding how and why vessels and arteries work

In her free time, Naomi Chesler spends a lot of time outdoors in such activities as rock-climbing, competing on both women's and co-ed Ultimate Frisbee teams, and playing with McGraw, her lab-shepherd mix.

But in the lab, she focuses her attention inward, studying the mechanobiology and biomechanics of veins and arteries. "It's important to know what the mechanical properties of tissues are if we want to replace them with bioengineered tissues," says Chesler, who will join the BME faculty in July as an assistant professor.

Also crucial, she says, is knowing how mechanical forces such as pressure and shear stress (the frictional force between a fluid and a wall) affect vascular biology. "We know that those are important to maintaining a healthy state," she says. "But what we don't understand is exactly how, mechanistically, pressure forces get transduced into biological signals and in particular, which biological signals they get transduced into."

In her research, Chesler often investigates the body's responses to health conditions such as high blood pressure, pulmonary hypertension and artherosclerosis. Currently, one project centers around how varying levels of pressure affect enzymes in carotid artery walls. "If you have hypertension, how are those abnormal mechanical forces affecting the biology of your artery wall?" she asks.

Others have shown that increased blood pressure stimulates cell proliferation and increases artery wall thickness. "In order for that to happen, certain enzymes probably have to degrade some of the structural components of the artery wall to make room for those cells to move and grow," she says. Her group found one pressure-dependent enzyme and another that had a pressure set-point so that it became more active as pressure either increased or decreased.

In another project, Chesler hopes to understand the mechanobiology and biomechanics of pulmonary artery vascular remodeling, which occurs during pulmonary hypertension, or high blood pressure in the arteries that supply blood to the lungs for oxygenation.

And in research supported by a National Science Foundation CAREER grant, she is studying what factors cause artherosclerosis, or hardening of the arteries, and the implications of these findings for vascular gene therapy delivery. What's known about artherosclerosis is that it often develops in smokers, and in people with diabetes or high cholesterol. It's age-dependent, and occurs mostly in branches and bifurcations of the circulatory system. "The interesting thing about branches and bifurcations is that the blood flow patterns are locally oscillatory, so that the shear stress changes direction frequently at the points where artherosclerosis develops. One of our questions is: What's going on, due to oscillatory shear stress, that makes these vessels develop this disease?" she says.

Two years into the study, Chesler and her group have found that vessels subjected to oscillatory conditions are leakier. It's a discovery that may yield benefits for patients when their disease is critical enough to require surgery. "If certain kinds of flow conditions can cause vessels to be leaky, then perhaps we can exploit that to deliver gene therapy to replacement vessels," she says. In particular, the knowledge might apply to saphenous veins — leg veins surgeons use in coronary artery bypass graft surgery. Now, only half those grafts last more than five or 10 years, she says.

Although vascular research occupies the lion's share of Chesler's time, she recently published a paper on mentoring strategies, based on the sociology of gender, for women in engineering. "That led to developing a workshop for untenured women faculty in the northeast region last year," she says. An Outward Bound experiential learning event, it focused on leadership skills and community-building. Another workshop later this year with the same cohort will work on writing skills. "The idea is to improve advancement and retention of women faculty through peer-mentoring and skill-based coaching, which we hope will also have a positive influence on increasing diversity in the engineering workforce down the line," she explains.

A native of Ann Arbor, Michigan, Chesler earned her PhD in medical engineering in the Harvard-MIT Division of Health Sciences and Technology Medical Engineering and Medical Physics Program. She comes to the BME department after working as an assistant professor of mechanical engineering at the University of Vermont. Chesler hopes to collaborate with engineering colleagues and others in UW-Madison's Medical School and its affiliated departments. And she is excited about the depth of expertise she's found here. "The BME department is an exciting, growing department and I think it's going to be a great place for me to continue my work," she says.

 

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Date last modified: Wednesday, 15-May-2002 15:43:00 CDT
Date created: 15-May-2002