Developing kidneys from scratch

To Alex Hughes, assistant professor in bioengineering in Penn's School of Engineering and Applied Science and in cell and developmental biology in the Perelman School of Medicine, the kidney is a work of art. "I find the development of the kidney to be a really beautiful process," says Hughes.

Densely packed with tubules clustered in units known as nephrons, kidneys cleanse the blood, maintaining the body's fluid and electrolyte balance, while also regulating blood pressure. The organ played a crucial role in vertebrates emerging from the ocean: as one paper puts it, kidneys preserve the primordial oceanin all of us.

Unfortunately, kidneys struggle in the modern world. Excessively salty food, being overweight, not exercising enough, drinking too much and smoking can all raise blood pressure, which damages the kidney's tiny blood vessels, as does diabetes.

In some cases, damage to the kidney's nephrons can be slowed with lifestyle changes, but, unlike the liver, bones and skin, which can regrow damaged tissue, kidneys have a limited capacity to regenerate. At present, without a transplant, the nephrons we have at birth must last a lifetime.

Eventually, chronic kidney disease leads to kidney failure, at which point there are only two treatments: dialysis-which costs tens of thousands of dollars per year, frequently causes pain, and requires patients to spend hours each week hooked up to machines that filter the blood-or kidney transplantation. The waiting list to receive a new kidney in the United States is roughly 100,000 people and three to five years long.

The Hughes Lab focuses on elucidating the mechanisms behind kidney development and using those insights to create kidney tissue from scratch, which could reduce the need for both dialysis and transplantation. "I think there's just enormous opportunity to think about synthetically reconstituting kidney tissues for regenerative medicine," says Hughes.

Read more at Penn Engineering Today.