SYSTEMS
BIOLOGY: Weaker Drug Combos May Make Stronger Medicine
It seems logical that the best approach to treating antibiotic-resistant bacteria
would be to look for combinations of drugs that together are more effective at
killing bacteria than the sum of their individual effects. But according to research
from Roy Kishony’s lab, this is not always the case. Two separate studies
appearing in Proceedings of the National Academy of Sciences show that
these synergistic combinations increase both the likelihood and the rate of evolution
of resistance. Meanwhile, antagonistic drug pairs—blends that together
are less effective—reduce the probability of evolution of resistance and
slow it down. The findings suggest that antagonistic drugs may be more clinically
valuable than expected. Pictured (clockwise from top left) are Kishony and lab
members Matthew Hegreness, Jean-Baptiste Michel, Noam Shoresh, Pamela Yeh, and
Remy Chait.
GASTROENTEROLOGY:
Gene Loss Inflames Bowel Disease
Inflammatory bowel disease (IBD) may arise from gut cells unable to cope
with the stressful job of mediating between the army of helpful bacteria
and the overprotective soldiers of the immune system. Experiments that
started in mice and extended to genetic analyses in people support a
longstanding and appealing idea that epithelial cells are key players
in the disease and not merely a vulnerable barrier between warring factions.
The report from the labs of Richard Blumberg and Laurie Glimcher appears
in the Sept. 5 Cell.
REGENERATIVE
MEDICINE: Technique Leapfrogs Stem Cells to Change Cell Type
A single tenet has long undergirded stem cell and regenerative biology:
for differentiated cells, their function is their fate, and only stem
cells can be coaxed into a desired cell type. But new research from
the lab of Douglas Melton, reported online Aug. 27 in Nature, rattles
that foundational principle to the core. By converting mouse pancreatic
exocrine cells into insulin-producing cells that are nearly identical
to the beta cells destroyed by type 1 diabetes, Melton and his collaborators
have demonstrated that even the most differentiated cells may be mutable.
Copyright 2008 by the President and Fellows of Harvard College