 Some animals like zebrafish can regenerate their body, their brain, retina, spinal cord, hearts, and a ton of other tissues, and soon we might be able to too. So it got me thinking about Wolverine. Wolverines don't regenerate. Why aren't there any superheroes based on zebrafish? So I got our graphics team to mock up a few. Oh. Hey. Oh. Uh. Uh-huh. Wow. Okay. Yikes. Uh, never mind. I get it now. Welcome to Lifespan News. I'm Emmett Short. Today we're talking about gene therapy to create regenerating metahumans. Why? Because it's Tuesday and that's what we do here. The journal Cell Stem Cell, and yes, that is a name, weird name, has published a study about animals that have been given the zebrafish like ability to restore their heart muscle after injury. According to the paper, you don't want genes responsible for regeneration stuck in the on position. That's how you get tumors. In zebrafish, these genes are controlled by trees, tissue regeneration enhancer elements, trees, and trees only turn on regenerative genes when they sense an injury. Heart tissue doesn't normally regenerate in adult mammals, but you're going to love this. In two similar experiments, researchers genetically engineered mice to express zebrafish trees in a way that would show visual indications only during injury response. It worked. In uninjured mice, there was no gene expression, but in the injured mice, the trees lit up like Christmas. The best part? It worked whether the injection was given before or immediately after the injury. So if this was a therapy, it could be conceivably given after a heart attack. Similar results were seen in pigs. They didn't have enough virus to infect the entire pig, so they just injected the pig's hearts. And I get that. Okay, these are tough economic times. I've stopped shopping to Whole Foods. So why inject an entire pig's body when you can get the same information with a much smaller dosage? There's no reason to go hog wild. The point is, even with just treating the heart, they got similar results to the mice. The indicators were only visible at the injury sites. So that's the targeting mechanism with trees. Now, the final experiments involved a molecule called YAP. There's a pun there. I'm going to pass it up because I respect you. YAP is a transcriptional cofactor that causes rapid cell growth and division when overexpressed. Without a tree to turn it on and off, genetically modifying animals to express YAP in the heart kills them within days due to basically having overgrown hearts. In the final test for restoring heart function, they used trees to control YAP expression. And they were able to restore core metrics of cardiac function, whether the injection was given before or immediately after the injury. And an improved function over an injured control group. YAP was only expressed during the injuries and only at injury sites. Basically, it turned off after the injury was healed. So tissue that can't heal itself did incredible. This was not yet a human clinical trial, but it is a significant step towards one and has the potential to become the standard of care for treating heart or who knows how many other types of damaged tissue. Imagine regrowing limbs, severed spinal cords or turning about the clock on your entire body. I need surgery on my thumb in April. I wish I could just get an injection and have it just repair itself. That'd be amazing. Maybe if I live long enough, that will be a reality. When there's more to share, we'll have it for you here. So make sure you subscribe and click the bell so you can stay up to date on aging research. I'm Emma Short and we'll see you next time on Lifespan News.