cover 2006

overconsumption of saturated fatty
acids, which are consumed
extensively in a Western diet, causes
intracellular accumulation of fat in
exocrine pancreas tissue and is
associated with cellular dysfunction
and cell death, ultimately
contributing to the pathogenesis of
pancreatic diseases.
Another aspect of Birk’s research
deals with the biological signals that
control satiety and hunger and the
mechanisms through which they
regulate the synthesis and secretion
of digestive enzymes by the exocrine
pancreas. She proved that some of
the signals that regulate satiety and
hunger also regulate the release or
inhibition of digestive enzymes.
Modifications of these signals
might serve as pharmaceutical
compounds that reduce digestion
and absorption of dietary fats.
Birk is also researching fat storage.
Overflow of fat into the body is
directed to storage at the most
efficient fat storage place – the fat
cell or adipocyte. Until some ten
years ago, it was thought that
adipose tissue was physiologically
inactive, designed mainly for
storage. Following the discovery
that it secretes many proteins that
signal the brain regarding the
amount of fat stored in adipose
tissue, the view has changed.
“This has opened a new world of
research on adipose tissue, not only
as a storage place, but as a
metabolically active tissue that plays
a critical role in the regulation of
satiety and hunger,” notes Birk.
Adipose tissue develops from
“innocent” pre-adipocytes into fully
differentiated storage cells that have
the metabolic capability of efficiently
storing fat. In this process, several
genes are “turned on” one after the
other in a known sequence. Birk’s
lab is studying a set of new genes
that play an important role in this
process. “We still need to learn the
complete sequence of genes
involved, which will enable us to
manipulate the formation or lack of
formation of adipose tissue. We also
study how this sequence is regulated
by specific fats and specific
metabolic states, such as diabetes
and obesity” says Birk.“ On one
hand, fatty acids act in enhancing
the formation of fully differentiated
fat-storing adipose cells. On the
other hand, some of these fatty acids
inhibit their formation.” Special fatty
acids also show promising results
when they are incorporated into
diets designed for people who want
to lose or gain weight. This research
is of interest not only in terms of
basic science; it is also a first step in
finding new strategies that could
facilitate or inhibit development of
adipose tissue.
With regard to Birk herself, does
she follow a strict dietary regime?
“I eat a balanced diet. I am not a
fanatic – we should never forget the
quality of life aspect,” she answers.
“We should always, though, be
aware of what we put in our
bodies.”
BGU NOW 43