Lysosomes play key role in development of inflammatory diseases
18 July 2012
Scientists at the University of East Anglia (UEA) have
discovered a ‘constant cloud’ of potent inflammatory molecules
surrounding the cells responsible for diseases such as thickening of the
arteries and rheumatoid arthritis.
findings could eventually lead to new treatments for chronic
inflammatory diseases. Cardiovascular disease arising from
atherosclerosis (thickening of the arteries) kills around 17 million
people worldwide each year, including 120,000 people in England and
Wales, while rheumatoid arthritis affects around 400,000 people in
The UEA team studied a type of white blood cell called monocytes,
which play an important role in the human immune system and help
protect our bodies against infection. But they can also invade
tissue, triggering the early stages of common inflammatory diseases.
The researchers detected for the first time that monocytes were
surrounded by a constant cloud. This cloud was found to be made up
of potent inflammatory molecules called adenosine triphosphate, or
ATP. Further study showed that the ATP molecules were being
propelled through the cell wall by the actions of lysosomes.
Lysosomes are sub-cellular compartments within blood cells which had
previously been thought to only break down cell waste.
“These unexpected findings shed light on the very early stages in
the development of inflammatory diseases such as atherosclerosis and
rheumatoid arthritis,” said lead author Dr Samuel Fountain of UEA’s
School of Biological Sciences.
“We found that lysosomes are actually highly dynamic and play a
key role in the way inflammatory cells function. This is an exciting
development that we hope will lead to the discovery of new targets
for inflammatory drugs in around five years and potential new
treatments beyond that.”
Dr Fountain said further study was now needed to investigate how
to control the release of ATP by lysosomes in monocytes and other
white blood cells, and to understand how inflammation may be
affected in patients with inherited diseases involving lysosomes.
1. Sivaramakrishna V, Bidula S, Campwala H, Katikaneni D and
Fountain S. Constitutive lysosome exocytosis releases ATP and
engages P2Y receptors in human monocytes. Journal of Cell
Science. Published online on July 5, 2012.