January 12, 2023  Print

For the first time, an international team of researchers has developed a method to reverse the loss of elasticity of damaged heart tissue following heart attacks.

After a heart attack, the shock of the event leaves behind a trail of damaged heart muscle,
which becomes a scar over time. However, the scar tissue doesn’t have the elasticity and
flexibility of healthy heart muscle, meaning there can be complications with pumping and
transporting blood.

For the first time, an international team of researchers has developed a method to reverse
the loss of elasticity of damaged heart tissue following heart attacks.

Heart disease is currently the largest cause of death globally.

Preclinical studies found a single injection of tropoelastin into the wall of the heart in
the days following a heart attack could ‘turn back the clock’ on muscle damage, making the
scars ‘stretchier’ and help improve the heart’s ability to contract.

Tropoelastin is the protein building block that gives human tissue its elasticity and ability to
stretch.

The results are published in Circulation Research and is the first time this potential of
tropoelastin in treating heart disease has been investigated.
 
IMAGE: Cross section of heart muscle sample. After the heart attack, it leaves behind scar made of collagen (pink). After tropoelastin is given, there is increased elastin (purple), which makes the scar less stiff and more flexible.

“This research showcases the potential of tropoelastin in heart repair and suggest further
work will show exciting possibilities of its role in future treatments and therapies,” says lead
researcher Dr Robert Hume who conducted the research at the Westmead Institute for
Medical Research (WIMR). Dr Hume is currently based at the University of Sydney’s Charles Perkins
Centre.

Repairing tissue damage from heart attacks
Four days after a heart attack, purified tropoelastin was injected into the heart.
Co-author Professor Anthony Weiss from the Charles Perkins Centre and Faculty of Science
explained: “Tropoelastin can repair the heart because it is a precise replica of the body’s natural elastic protein.”

For this injection, the researchers used a new surgical method utilising ultrasound to guide
the needle into the heart wall, which is less invasive than previous methods.
 
IMAGE: Echocardiography of the heart wall. LVAW is the section after a heart attack and shows scarring damage compared to LVPW which is healthy. Tropoelastin was given 4 days after a heart attack, then the heart recovered as shown by the wave-like patterns. 


After 28 days the researchers found the heart muscle, originally damaged and scarred at
the beginning, regained its elasticity and resembled muscle function similar to before the
heart attack.

Further tests found tropoelastin reduced scar size and essentially stabilises it by increasing
its elastin content and therefore decreasing the stiffness of the scar.

Additional experiments on human cardiac fibroblasts (a subset of human heart cells
responsible for maintaining the structure of a normal heart), in a petri dish showed after the
cells were treated with tropoelastin, they were able to generate elastin.

Elastin is a crucial protein that gives human tissue elasticity and the ability to stretch.
“What we have found is highly encouraging,” says senior author, WIMR's Associate Professor James
Chong.

“We hope to continue developing the method so it can eventually be used in a clinical setting
and used to treat and improve the lives of the millions of heart failure patients worldwide.”

Watch the 9 News report about this research here: https://bit.ly/3X6vLZF