Scientists Found the Gene Responsible for Signalling When to Urinate

A study on both mice and humans who are part of the Clinical Center trial and funded by the National Institutes of Health, discovered the gene responsible for the urge to urinate.

The result, published in Nature, said this gene is called the PIEZO2 that signals the brain that the urinary bladder is full and needs to be emptied. Not only that, the results suggest that there could be several senses that this gene can control.

Senior author of the paper Ardem Patapoutian, Ph.D., a professor from Scripps Research Institute in La Jolla, CA, said that urinating is essential to the health as it is one way to excrete waste. This study shows the gene that is responsible for that function and what critical role it plays.

"We hope that these results provide a more detailed understanding of how urination works under healthy and disease conditions," says Dr Patapoutian.

Is PIEZO2 the Sixth Sense?

The excretory system of the body is responsible for excreting wastes that may pose harm to the body. The kidney filters the waste and excess water which becomes urine and store it in the urinary bladder. At some point when it is already full, the bladder muscles signal the brain that it has already reached its limit, which triggers the urge to urinate.

The study found that patients who were born with a deficiency in the PIEZO2 gene have trouble sensing that their bladder is already full. Meanwhile, the researchers also found that this gene functions in two ways in mice. It helps the bladder gauge its expansion and sparks neurons to send tension signals to the brain than to the rest of the nervous system.

The PIEZO2 was discovered by Dr Patapoutian back in 2010 along with a gene called PIEZO1. But even before then, they have already observed that a gene in a few samples of mice, worms, and flies sense changes in shape and pressure.

Dr Patapoutian and his team discovered that PIEZO2 plays many roles throughout the body, including vibration, pain, proprioception, and the sense of touch as well as the unconscious awareness of one's body in space, according to NIH.

PIEZO2 is Responsible For the Urge to Urinate

It was just recently that the researchers discovered the gene's role in urination. Back in 2015, the NIH researchers found that people with mutated PIEZO2 genes had no sense of proprioception and could not feel some forms of sense of touch and pain similar to the results they found in mice.

Initially, the researchers found that the gene was highly active in some dorsal root ganglion (DRG) neurons ad saw that the cells lit up when the bladder is full. They also found that some umbrella cells within the bladder activate the PIEZO2 during bladder activity.

Furthermore, they also discovered that deleting PIEZO2 from the neurons and umbrella cells reduce the cell's response to the bladder and caused a urination problem in the mice. Also, when they deleted the gene from the two cell types, they found that it has more prolonged effects.

"Our results show how the PIEZO2 gene tightly coordinates urination," said Dr.Alex Chesler, PhD. "This is a major advance in our understanding of interoception - or the sense of what's going inside our bodies."

The researchers plan to further study the role of the gene in urination and other interoceptive senses and explore the implications PIEZO2 has on helping people with urinary problems.