|June 8, 2007
Hundreds More Players Spotted on DNA Repair Team
A surprisingly vast molecular emergency team responds to the everyday genetic
nicks and dings caused by chemicals, foods, radiation, and oxygen byproducts,
says a study in the May 25 Science. The research expands the sparse
ranks of known DNA damage–response proteins from a couple dozen to a legion
of more than 700. The authors on this and related papers include (from left)
Bin Wang, Shuhei Matsuoka, Stephen Elledge, and Agata Smogorzewska.
Vitamin A Derivative Reins In Weight Gain
The vitamin A derivative retinaldehyde is well known for its role as
a photoreceptor in the eye, but it may also be a potent regulator of
fat metabolism. HMS researchers, including Ouliana Ziouzenkova
(right), Jorge Plutzky, and colleagues, reported online
May 27 in Nature Medicine that the retinoid suppresses fat cell
development and protects against diet-induced obesity and diabetes. The
discovery places retinaldehyde in a new light and opens up a new angle
for the study of energy balance. The finding may also lead to new ways
to control excessive weight gain.
THE ENVIRONMENT: Water, Water Everywhere
But there’s hardly a safe drop to drink in many developing countries.
Bangladesh is a case in point. Two of the world’s mightiest rivers,
the Ganges and the Brahmaputra, merge in Bangladesh, yet many residents
are going thirsty after naturally occurring arsenic was found in the country’s
vast network of wells. This and similar calamities were explored in a symposium
at HSPH, titled The Impact of the Global Water Crisis on Health and Human
Development. The program was organized by International Science and Health
Network graduate students (from left) Julia Fisher, Anshul Mathur, and
BIOPHYSICS: Shape-shifting of Cells Gives Body Stretch
How is the ketchup that stubbornly hugs a glass bottle but then
gushes in one burst similar to the cells of your body? According to research
by Jeffrey Fredberg (left), Xavier Trepat, and colleagues, cells have the
same physical properties as mundane materials like ketchup, toothpaste, shaving
foam, clay, and mayonnaise—so-called “soft glassy materials” that
behave like solids but rapidly fluidize under shear force. A paper in the
May 31 Nature from Fredberg’s lab demonstrates that cells
can also shift from a solid to a liquid form when stretched, an ability that
might underlie their astounding physical flexibility.
Homegrown Cure For Autoimmune Disease
Researchers in the lab of Harvey Cantor have discovered a way to help
the immune system help itself to destroy the destructive T cells responsible
for autoimmune diseases such as type 1 diabetes and multiple sclerosis.
The work, by Linrong Lu (right), Dan Hu, and colleagues reveals a natural
mechanism of immunosuppression that involves the direct killing of self-reactive
T cells by another immune actor, the natural killer (NK) cell. The lab’s
most recent study, in the May Immunity, brings to light an unexpected
regulatory role for these deadly attackers, better known for their ability
to purge tumor cells or virus-infected tissues.