 Lipids
Linked to Nervous System Development
Blocking a signaling lipid can keep
nerves from developing the arm-like extensions they need to wire the
body and may even cause neurons to die, researchers have found.
The researchers hope this understanding of how the central nervous
system develops in the first place will one day help them repair loss
from injury or disease.
It has already helped them understand the ailments of a mouse model
with about 20 percent function of the protein that helps the lipid reach
the cell surface to help axons grow, said Dr. Wen-Cheng Xiong,
developmental neurobiologist and corresponding author on the study
published in the November issue of Nature Cell Biology.
The mutant mouse is small and has motor neuron degeneration, with
tremors, short limbs and a short life. This work unraveled the mystery
of what the blocked lipid transfer protein regulated. The lipids help
give shape and function to cell units including the nucleus and
mitochondria.
“Traditionally, people didn’t think these lipids were regulated. They
thought they were just there,” said Dr. Xiong. “But what we found is
this particular lipid is regulated; it’s like a signaling molecule.
Especially during axon growth, the dynamic regulation is more dramatic.”
She and her colleagues found the lipid is transferred to the cell
surface at just the right time and place by phosphatidylinositol
transfer protein-a, which humans also have. It’s been known that many
proteins can be regulated, especially signaling proteins that enable
intracellular chatter. “Now we have found this protein regulates lipids
and lipids also travel,” Dr. Xiong said.
The mutant mouse embodies what can happen when the lipids don’t
travel. The researchers also studied a similar mutant chick embryo that
had reduced axon growth. For this paper, they added the zebrafish
embryo, which forms most of its major organs within 24 hours and remains
transparent for the first few days of life, to further document the role
of these regulated lipids and their transfer protein.
When they injected an agent that blocks expression of a related lipid
transport protein, they could almost immediately see the impact on
axon growth and neuron survival, said Dr. David J. Kozlowski,
developmental geneticist and director of the MCG Transgenic Zebrafish
Core Laboratory. The greater the suppression, the greater the resulting
defect.
Next, they’ll use a version of the transgenic zebrafish to watch
axon development in live embryos and in real time. They also will study
what happens to lipid activity in an injury model. They already know
some signaling proteins are disturbed.
The work was supported by the National Institutes of Health.
--Toni Baker
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Six MCG alumni and faculty received honors for artwork at the 60th
annual meeting of the Association of Medical Illustrators in Thousand
Oaks, Calif.
Andrew Swift, assistant professor of medical illustration at MCG and
a 1999 alumnus of the Department of Medical Illustration, won the Ralph
Sweet Best of Show Award for his instructional color illustration,
“Chlamydia’s Stealthy Attack,” featured in the article, “Can Chlamydia
be Stopped?” in the May issue of Scientific American.
Awards of Excellence were given to Knox Hubard, class of 2000, for
his medical-legal illustration, “Nonunion of Humeral Fracture: Internal
vs. External Fixation,” and Chris Nadolski, class of 2000, and Eric
Olson, class of 1999, for their interactive media presentation, “Merck
Ophthalmology Virtual Preceptorship.”
Craig Foster, class of 1992, received two Certificates of Merit in
the animation category for “A Closer Look at the Role of Progestins in
Hormonal Contraceptives” and “Control of Prosthetic Bacterial Infection
with Silver Ions.” Mr. Swift’s color illustration, “Chlamydia’s
Stealthy Attack” also won a Certificate of Merit for the instructional
color category.
MCG medical illustrator Michael Jensen, class of 2005, received a
Certificate of Merit for his animation, “An Introduction to the
Corticospinal Tract.”
In a separate venue, Kristen Larson, class of 2006, received an Award
of Excellence for her illustration, “Laparoscopic Cholecystectomy” in
the exhibition, “Art in Medicine: Illustrations of Human Anatomy” at the
Hearst Center for the Arts in Cedar Rapids, Iowa. The exhibition is on
display through Oct. 16 in the Dahl-Thomas Gallery of the Hearst Center.
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[Top]
 Dr.
Brann Receives Distinguished Alumni Award
Dr. Darrell W. Brann, professor and associate director of the Medical
College of Georgia Institute of Neuroscience, received the 2005
Distinguished Alumni Award from his undergraduate alma mater, Henderson
State University in Arkansas.
Dr. Brann, who earned his Ph.D. in endocrinology from MCG in 1990,
received the MCG School of Graduate Studies Distinguished Alumi Award in
2001. He completed postdoctoral training in neuroendocrinology at MCG
before joining the faculty in 1992.
He is an ad hoc member of the Integrative and Clinical Endocrinology
and Reproduction Study Section of the National Institutes of Health and
a member of the NIH’s FO2A Neurosciences Fellowship Study Section. He is
a reviewer for a number of journals including the American Journal of
Physiology, Brain Research, Journal of Neuroscience, Endocrinology and
Neuroscience.
He is co-director of a five-year NIH training grant in
neurodegenerative diseases and neural repair. His research is funded by
two NIH grants.
Dr. Brann received the 2005 Outstanding Basic Science Teaching Award
from the MCG School of Medicine.
[Top]
 Graduate
Students Receive Awards
Two MCG graduate students received awards recently.
Pharmacology student Jason Niehaus received the inaugural Darrell W.
Brann Scholarship Award in Neuroscience. The $1,000 annual scholarship,
administered by the School of Graduate Studies and Institute of
Neuroscience, was established and endowed for the next 10 years by Dr.
Brann, neuroscientist and associate director of the Institute of
Neuroscience. The award was created in support of the neurosciences
Ph.D. program that began this year. In 2004, Mr. Niehaus earned a
two-year predoctoral fellowship from the National Institutes of Health
and won a scientific achievement award for his presentation at the
annual meeting of the International Cannabinoid Research Society.
 Jin-Na
Min received the Institute of Molecular Medicine and Genetics Rasmussen
Award for research excellence. The $500 scholarship award honors the
founding director of IMMAG, the late Dr. Howard Rasmussen, and is funded
by IMMAG faculty. Before enrolling at MCG, she spent six months working
at MCG as a predoctoral fellow in the laboratory of Dr. Nahid Mivechi,
associate professor of radiobiology. At the 2005 IMMAG retreat, she
presented her research on two tumor suppressor genes that regulate tumor
growth, “Genetic interplay between hsf1 and p53 in tumorigenesis.”
[Top]
Dr. Cameron Named Associate Dean
 Dr.
Patricia Lee Cameron, assistant dean for recruitment and admissions in
the School of Graduate Studies, has been promoted to associate dean.
“Dr. Cameron has done an outstanding job as assistant dean since her
appointment in 2002,” said Dr. Gretchen Caughman, dean of the School of
Graduate Studies. “As associate dean, she will continue to focus on the
recruitment and admissions aspects of our programs as well as assist me
in the day-to-day operations of the school.”
Dr. Cameron is the director of undergraduate research programs and a
member of the School of Graduate Studies Graduate Council, the MCG
Student Training and Research Program Committee and the University
System of Georgia Academic Committee on Graduate Work. She also is a
member of the American Society for Cell Biology.
Dr. Cameron joined the MCG faculty in 2000 after completing a
postdoctoral fellowship at MCG’s Institute of Molecular Medicine and
Genetics, where she is also an assistant professor of developmental
neurobiology. She earned her Ph.D. in cell biology from Yale University
in 1992.
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