Scientists Find New Heart Cell That Could Repair Damage

Scientists at Weill Cornell Medicine have found a previously unknown cell type that could change how we heal damaged hearts.

The team, led by Dr. Jingli Cao, discovered these special "perivascular" cells while studying zebrafish hearts. These tiny fish have an amazing ability humans lack: they can fully regenerate their hearts after injury.

The new cells act like construction managers for blood vessels. They wrap around coronary arteries and release signals that control how much new blood vessel tissue grows. Think of them as knowing exactly when to build and when to stop building.

Dr. Cao's team traced these cells back to their origin in the epicardium, the thin outer layer surrounding the heart. When the heart gets injured and oxygen levels drop, a gene called scxa activates and directs certain stem cells to become these helpful perivascular cells.

The timing matters as much as the cells themselves. "During development or when the heart is damaged, you need to build the right amount of blood vessel and you need to know when to stop," Dr. Cao explained. "This system provides that layer of control."

The researchers published their findings in Nature Communications in August 2026. They spent years cataloging which genes turn on when zebrafish hearts get injured, eventually pinpointing the scxa gene as the master switch.

Humans actually have a related gene called SCX, but it currently works against us. After a heart attack, SCX activates in cells that create scar tissue rather than healthy new muscle. That scar tissue weakens the heart permanently.

The Bright Side

Dr. Cao and his team are already testing whether they can reprogram human heart cells to behave more like their zebrafish cousins. They're working with cultured human epicardial cells and cardiac organoids to create what Dr. Cao calls a "biological bandage."

The vision is straightforward: activate the right cells at the injury site to grow new heart muscle and blood vessels in controlled amounts. Instead of forming a weak scar after a heart attack, the heart could rebuild itself with functional tissue.

Dr. Cao remains realistic about the timeline. "I don't think there will be just one magic factor that controls regeneration," he said. "But we've discovered one more factor, one more mechanism that could eventually contribute to turning on epicardial cells and repairing human hearts."

Graduate student Björn Perder and postdoctoral fellow Dr. Yu Xia worked alongside Dr. Cao on the discovery. Their careful gene mapping revealed not just a new cell type, but an entire system for controlling blood vessel growth.

The research adds another piece to the puzzle of heart regeneration, bringing scientists closer to a future where damaged hearts can truly heal.