Spider venom may offer stroke therapy

A protein in spider venom may help protect the
brain from injury after a stroke, according to
research.
Scientists found a single dose of the protein Hi1a
worked on lab rats.
They said it showed "great promise as a future
stroke treatment" but had not yet been tested in
human trials.
The Stroke Association said the research was at
its early stages but it would "welcome any
treatment that has the potential to reduce the
damage caused by stroke".
The researchers, from the University of
Queensland and Monash University, travelled to
Fraser Island in Australia to hunt for and capture
three potentially deadly Australian funnel web
spiders.
"We regularly collect spiders from Fraser Island
off the south coast of Queensland," explained
lead researcher Prof Glenn King.
"The reason for this is that funnel-web spiders
dig burrows that can be as deep as 20-30 cm.
Thus, digging them up from hard clay soils is
very difficult. Fraser Island is a sand island which
makes it easy for us to extract the spiders from
their burrows."
The team then took the spiders back to their
laboratory "for milking".
This involved coaxing the spider to release its
venom, which could then be sucked up using
pipettes.
Next the scientists dissected the venom gland of
the spiders and honed in on a protein in the
venom to recreate a version of it in their lab.
They then injected this Hi1a into the lab rats.
A stroke is a brain attack that happens when the
blood supply to part of the brain is cut off or
there is bleeding on the brain
Every two seconds, someone in the world will
have a stroke
Almost 17 million people who had never had
a stroke before had one in 2010
Stroke is the second most common cause of
death, causing about 6.7 million deaths each
year, one every five seconds
Almost one in every eight deaths is caused
by stroke
The burden of stroke-related illness, disability
and early death is set to double within the
next 15 years
Source: Stroke Association
They found that the protein blocked acid-sensing
ion channels in the brain - something the
researchers say are key drivers of brain damage
after stroke.
Prof King said the protein showed "great promise
as a future stroke treatment".
"We believe that we have, for the first time, found
a way to minimise the effects of brain damage
after a stroke.
"Hi1a even provides some protection to the core
brain region most affected by oxygen deprivation,
which is generally considered unrecoverable due
to the rapid cell death caused by stroke."
The research was published in Proceedings of the
National Academy of Sciences.
Why look to spider venom in the first place? Prof
King explains:
"My lab is interested in developing drugs for
human nervous system disorders. Many of these
disorders involve either dysfunctional ion
channels (e.g. epilepsy) or over-active ion
channels (chronic pain and stroke).
Thus, we are typically looking for molecules that
modulate the activity of ion channels. The
venoms of small venomous invertebrates such as
spiders, centipedes and scorpions have evolved to
target the nervous system of insects, and
consequently they are absolutely full of ion
channel modulators.
Because the human nervous system is more
complex and wired differently to insects, ion
channel modulators that kill or paralyse insects
can actually be beneficial to humans. Thus,
looking in venoms for ion channel drugs is not as
weird as it seems."
Dr Kate Holmes, deputy director for Research at
the Stroke Association, said: "We do not have an
accurate picture of what happens in human
brains from this research, therefore, it is currently
unknown if this could be a successful treatment
option for humans in the future.
"We welcome any treatment that has the potential
to reduce the damage caused by stroke,
particularly if this can benefit people who are
unable to arrive at hospital quickly.
"Current treatments must be given in half this
time period, and it is too early for us to know if
this research can offer an alternative for stroke
patients.
"We urge for stroke to be treated as an
emergency - the sooner a person can get to
hospital after a stroke, the sooner the right
treatment can be received, which can improve
survival and help recovery."