Mysterious Enzyme to Stop Internal Bleeding Identified

A new approach for treating thrombocytopenia has been uncovered. Thrombocytopenia puts people at risk for internal bleeding.

An enzyme that boosts platelet production and may work as a future therapeutic in thrombocytopenia condition, found Scripps Research scientists. The findings of the study are published in Proceedings of the National Academy of Sciences. //

"This opens up new options for treating diseases of the blood," says Paul Schimmel, PhD, professor at Scripps Research and co-senior author of the study with Professor Zaverio Ruggeri, MD, of Scripps Research.

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‘YRSACT is the key to one method of platelet production. Animals injected with YRSACT showed a dramatic increase in platelet production, especially under stressful conditions, such as radiation similar to what cancer patients face.’

Previous research had shown that while the enzyme YRSACT has a crucial role in decoding DNA (a process called translation), it appears to have additional jobs in the cell. YRSACT was abundant in blood platelets, the cells that let wounds clog and heal. So, the Schimmel and Ruggeri labs sought to uncover why.

"Our animal study indicated accelerated platelet recovery, not only in antibody-induced thrombocytopenia, but also in radiation-induced thrombocytopenia," says study first author Taisuke Kanaji, PhD, MD, an institute investigator at Scripps Research.

So how does YRSACT work? The researchers found that YRSACT increases the production of large bone marrow cells called megakaryocytes, which are the precursors to platelets.

Quiz on Bleeding Disorders
Bleeding disorder is a rare condition that impairs how the body regulates blood coagulation. In case of an injury, bleeding can occur in the organ internally or externally. Under normal circumstances, the blood vessels constrict to reduce the blood flow, and a clot is formed with the help of platelets and coagulation factors present in the blood. The clotting process is impaired in people with bleeding disorders ().

There are 10 questions on ‘Bleeding Disorders’ in this quiz that will explore the depth of your knowledge and provide answers to the following:

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Symptoms of Hemophilia ()
Hemophilia and Gender ()
Complications of Hemophilia ()
Diagnosis of bleeding disorders ()

Until this discovery, thrombopoietin (TPO) was previously the only other protein known to increase platelets. Schimmel says a version of TPO is currently used as a drug to treat some cases of thrombocytopenia. However, TPO has limitations, making it unsuitable and hazardous in some clinical settings.

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Showing that YRSACT could be useful in human patients posed its own challenges. Congenital thrombocytopenia is rare, and even finding the right blood cells to test in thrombocytopenia patients is like finding a needle in a haystack.

Remarkably, the Scripps researchers were able to team up with a group at the Center for iPS Cell Research and Application at Kyoto University to test a stem cell line developed from a thrombocytopenia patient.

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"I think this was a beautiful collaboration of groups having distinct expertise to work together to accomplish our goal," says study co-first author Sachiko Kanaji, PhD, MD, a staff scientist at Scripps Research.

Their findings in these human cells further confirmed that YRSACT can control a mechanism in cells to produce life-saving platelets.

Taisuke Kanaji says the next step in the research is to understand the conditions-from infections to radiation-that prompt the body to activate YRSACT on its own.

Source-Eurekalert