Research in Real Time
Using novel approaches to study kidney disease and other disorders,
researchers at the Indiana Center for Biological Microscopy leave
no stone unturned.
Dramatically advanced technology and some far-sighted planning
have converged to create one of the nation’s most advanced
microscopic imaging facilities at the IU School of Medicine. The
Indiana Center for Biological Microscopy, whose activities are overseen
by Bruce Molitoris, MD, director of the Division of Nephrology,
has gathered the resources and expertise to provide advanced imaging
services for scientists at IU and across the nation.
Using powerful microscopes, computers and software, precise lasers,
and molecules that give off a fluorescent glow, researchers can
see inside cells to view their structure, note where particular
proteins congregate, or even watch in real time proteins move along
cellular pathways.
Dr. Molitoris says developing the center was the reason he came
to the School ten years ago, bringing the first imaging equipment
with him and starting the grant process that has made the center
possible.
“The ability to safely utilize microscopy in living cells
and animals, to obtain information at cellular and intracellular
levels, has revolutionized our approach to understanding the biology
of disease states,” he says. Moreover, he notes that scientists
can watch the actions of drugs and other agents in cells, judging
their effectiveness.
The sequencing of the human genome has provided scientists with
a growing understanding of the genes that provide the instructions
for activities in the cell. Now researchers are looking even more
closely at the proteins that are built on orders from the genes
and that carry out the genes’ instructions.
Fluorescent microscopy provides a powerful tool to study those proteins
in new ways, says Kenneth W. Dunn, PhD, scientific director of the
center and associate professor of medicine in the Division of Nephrology.
It also enables scientists to eliminate a thorny problem: the traditional
process of examining cells usually kills them. But modern microscopy
enables researchers to look at live cells and to watch the internal
dynamics of crucial activities such as calcium regulation.
“The cool thing is, this is very specific. This shows you
exactly where in the cell your protein is,” says Dr. Dunn.
“It’s guilt by association. You can tell a lot about
what a protein does based on the cell compartment it is located
in and the other proteins it interacts with.”
Kid in a Candy Store
That’s what Carrie L. Phillips, MD, learns as she uses microscopy
techniques to study polycystic kidney disease, a genetic disorder
that is estimated to affect more than 600,000 Americans and millions
worldwide, according to the Polycystic Kidney Disease Foundation.
People with the disease develop cysts on their kidneys that grow
and multiply over time, eventually forcing patients to undergo dialysis
or transplants.
Dr. Phillips, an assistant professor in the Department of Pathology
and the Division of Nephrology, says microscopy techniques enable
her to see where the cysts develop in the kidney tubules, the tiny
channels that carry urine from the kidney’s filters on its
route to the bladder.
Learning where that cyst development occurs can help her understand
how it occurs, she says. Moreover, she can observe what’s
happening at the level of proteins, not just at the larger structural
level.
Microscopy also can substitute for hand-dissecting the tubules,
a tedious process that she compares to manipulating a big bowl of
spaghetti with tweezers.
“What it took somebody months by hand-dissecting we can figure
out in ten minutes on the microscope,” Dr. Phillips says.
“I’m like a kid in a candy store with this equipment.”
In part, Dr. Phillips notes, the microscopy work will help establish
that the mouse model with which she is working is a good model of
human polycystic kidney disease. It also enables her to more easily
study the role of an abnormal protein produced in that mouse, a
protein that appears to be part of a big pathway of interacting
proteins involved in the development of cysts.
Systematic Approach
The equipment includes seven advanced microscopes along with computers
and other equipment for analyzing information. Center staffer Jeff
Clendenon has developed a software package called Voxx that lets
researchers translate the huge amounts of data collected into images
using the graphics capabilities of standard personal computers.
“We have a complete array of systems to attack any problem,”
Dr. Dunn says.
Four of the microscopes are confocal systems which allow investigators
to perform optical sectioning of a sample by focusing at a specific
depth. By imaging the sample on a series of different planes, a
three-dimensional image can be created.
The center’s goal, says Dr. Dunn, has been to provide state-of-the-art
imaging facilities for researchers that would be too expensive for
an individual lab to acquire, use effectively, and maintain. Use
of the center by IU faculty has been growing by thirty-five percent
a year, and scientists from outside IU are using it as well.
Funding for the center has come from the IU School of Medicine,
the Indiana Genomics Initiative, and the National Institutes of
Health. In 2001 the NIH awarded the center a $5 million George M.
O’Brien Kidney Research Center grant to develop new microscopy
techniques for kidney researchers.
The grant also funds education activities, continuing education
sessions for high school and college biology teachers, and an annual
program that brings gifted Indiana high school science students
to campus for two days of hands-on science.
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