Researchers at Cedars-Sinai have developed an experimental RNA-based drug, TY1, that repairs DNA, reduces scar tissue, and could pave the way for new treatments for heart attacks and autoimmune diseases.
A New Approach to Healing
“By studying stem cell therapy, we discovered a way to heal the body without using stem cells,” said Dr. Eduardo Marbán, MD, executive director of the Smidt Heart Institute at Cedars-Sinai and senior author of the study. “TY1 is the first exomer—a new class of drugs that target tissue damage in unexpected ways.”
TY1 is a lab-engineered version of a naturally occurring RNA molecule. The drug boosts the activity of a gene called TREX1, which enables immune cells to clear damaged DNA, promoting tissue repair.
Two Decades in the Making
TY1’s development builds on more than 20 years of research. Marbán’s earlier work at Johns Hopkins University focused on isolating progenitor cells from the human heart. Like stem cells, progenitor cells can develop into new tissue, but they do so in a more targeted manner, helping regenerate damaged cardiac tissue.
At Cedars-Sinai, Dr. Ahmed Ibrahim, MPH, discovered that heart progenitor cells release tiny, molecule-filled sacs called exosomes. These exosomes carry RNA molecules that aid in tissue repair.
“Exosomes are like envelopes with important information,” Ibrahim said, associate professor in the Department of Cardiology and first author of the study. “We wanted to decode these messages to identify which molecules had therapeutic potential.”
From Discovery to Synthetic Drug
Sequencing the RNA inside exosomes revealed one molecule as particularly abundant, suggesting a key role in healing. Laboratory tests confirmed that the natural RNA promoted tissue repair in animal models of heart attack. TY1 is a synthetic version of this molecule, designed to mirror RNA drugs already approved for clinical use.
TY1 works by enhancing the production of immune cells that reverse DNA damage, reducing scar tissue formation after heart attacks.
“By improving DNA repair, we can heal tissue damage from heart attacks,” Ibrahim said. “TY1 also shows potential in treating autoimmune diseases, where the body attacks healthy tissue. This represents a completely new mechanism for tissue healing and opens doors to therapies for a range of conditions.”
Next Steps
The research team plans to advance TY1 to clinical trials, marking an important step toward developing new regenerative medicines and RNA-based therapies.
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