57 / 116
a profile provides a snapshot of the
biological state or activity of any
cell or tissue type after exposure to
some stressor.
Measuring the gene expression
of several hundred to thousands of
genes reveals patterns that point to
the factors instigating the changes.
For example, while we usually think
of our immune system in terms
of host defense against things that
are bad for our health, such as
viruses or bacteria, I believe that
the immune and inflammatory
responses that we see in healthy
divers are markers of successful
short-term adaptation.
Perhaps the changes we see are
directly involved in antioxidant
defenses. Right after scuba diving we
see upregulation of genes that code
for essential antioxidant enzymes
such as mitochondrial superoxide
dismutase 2 (SOD2), glutathione
peroxidase 4 (GPX4), thioredoxin-1
(TXN1) and nuclear factor kappa
B (NF-kB). These factors are
known to play roles in the body’s
defense system. It is possible that
such upregulation is a defensive or
adaptive response to environmentally
incurred oxidative stress, an
imbalance that occurs when the body
cannot counteract the harmful effects
of or repair damage caused by free
radical production.
Is there a relationship between
repeated diving exposures and
immune-system health?
We know that repeated exposures
to certain chemicals affect long-
term risks of some autoimmune
conditions and cancers, but we do
not yet know how diving affects the
immune system in the long term.
Even when there are no symptoms
of DCS, secondary health effects
may arise from the biological
defenses activated during diving to
protect us from acute injury.
Changes that affect immune
cells may alter our susceptibility
to infections and our long-term
risk to diseases. If we can identify
the biological processes altered
by diving and determine whether
they become fixed in our immune
system over time, we may be able to
better prepare divers and improve
medical follow-up.
What can gene expression tell us
about a person’s risk of DCS?
Although changes in gene
expression do not yet amount to
a diagnosis of DCS, in the future
these changes may provide clues
in the search for objective
biomarkers during the diagnostic
process. Understanding the
biological processes involved in
disease development is useful
for implementing targeted
prevention and treatment and is
necessary for the advancement of
precision medicine.
Normally, a physician detects
disease through clinical evaluation,
but changes in gene expression may
point to risks and causes before
signs or symptoms are noted. It
is possible to count the number
of transcripts made to determine
the amount of gene activity
or expression. By comparing
transcriptomes (all the ribonucleic
acid [RNA] transcripts within
a cell) of different types of cells,
one can determine a normal level
of gene activity and assess how
changes from that set point may
contribute to disease or DCS for
a given individual. Much more
research will be needed before we
can leverage this approach to yield
useful information.
Short-term adaptive immune and
inflammatory responses happen as
a response to acute environmental
stress, but these responses are
successful only if the diver surfaces
without illness. Short-term
success may come at a price if
acclimatization increases the risk of
other diseases in the long term.
ALERTDIVER.COM|
55
DIVING AS IT SHOULD BE!
Experience the best diving the
Turks & Caicos Islands have to offer.
1-800-234-7768
www.diveprovo.com