Sydney: Clot-busting
enzymes perform double job - removal of blood clots and disposing
of cells that die prematurely from disease or trauma, says a
study.
Scientists from Monash University have demonstrated for the first
time how the enzyme t-PA, plays a vital role in these two
functions.
Necrosis occurs when cells in living tissue die prematurely due to
external stress or injury. The body's system for removing waste
linked with necrotic cell removal was not, until now, well
understood, the journal Cell reported.
Professor Robert Medcalf and Andre Samson, from Monash's
Australian Centre for Blood Diseases (ACBD), led the research with
Stephen Bottomley, professor of biochemistry and molecular
biology, at Monash.
They found that in the late stages of death, the injured cell
undergoes a restructure and takes on a form not unlike a blood
clot, to prepare for efficient removal from the body. This process
had never been described before, according to a Monash statement.
Medcalf said the blood clot-like structure allowed the damaged
cells to be recognised and removed by t-PA and its enzymatic waste
disposal team.
"It's exactly the same principle as the formation and removal of a
blood clot," he said.
The researchers were studying brain tissue when they made the
discovery, but have shown that the same process applies to every
cell in the body.
"It's very efficient. Instead of doubling up, the body is using
the same disposal system to eliminate a variety of unwanted waste
products, be they dead cells or blood clots that have served their
purpose," Medcalf said.
"What this means is that t-PA and its team of enzymes recognises
waste through structure or shape, not by the specific proteins
involved," concluded Medcalf.
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