MONDAY, Oct. 26, 2020 (HealthDay News) -- Scientists say they have spotted the gene responsible for telling you when it's time to pee.
The gene, called PIEZO2, may help at least two different types of cells sense when the bladder is full and needs to be emptied.
"Urination is essential for our health. It's one of the primary ways our bodies dispose of waste. We show how specific genes and cells may play critical roles in initiating this process," said study senior author Ardem Patapoutian, a professor at the Scripps Research Institute, in La Jolla, Calif. "We hope that these results provide a more detailed understanding of how urination works under healthy and disease conditions."
The study, which was funded by the U.S. National Institutes of Health (NIH) and included NIH researchers, was published recently in the journal Nature.
The PIEZO2 gene has instructions for making proteins that are activated when cells are stretched or squeezed. The researchers found that patients who are born with a genetic deficiency in PIEZO2 have trouble sensing when their bladder is full, and experiments in mice suggest the gene has two roles in this process.
According to study lead author Kara Marshall, "There were a lot of reasons to think that PIEZO2 could be important for urination. Theoretically, it made sense as it is a pressure sensor for other internal sensory processes." Marshall is a postdoctoral researcher at Scripps.
In 2015, researchers discovered people who were born with mutations in their PIEZO2 genes. They had no sense of the movement of the body and could not feel some types of touch and pain. They also had something else in common, the study authors said in an NIH news release.
"We were really struck by what we heard during background interviews with patients and their families," said researcher Dr. Dimah Saade, a clinical fellow at the NIH. "Almost everyone mentioned that the patients had problems with urination. As children, they had trouble potty training. They would often have urinary tract infections. And most of them follow a daily urination schedule. After seeing a consistent pattern, we decided to take a closer look."
Almost all of the patients said they could go all day without feeling the need to urinate, and most urinated less than the normal five to six times per day.
Marshall said, "These results strongly suggested that PIEZO2 plays a role in urination. We wanted to know how it may do this." Experiments in mice helped find the answer.
The researchers found that the PIEZO2 gene was highly active in a few neurons that send nerve signals from the mouse bladder to the brain. Aided by an imaging system, they saw that the cells lit up with activity when a mouse's bladder filled.
"These were the first clues to understanding wherein the urinary tract PIEZO2 worked. They suggested that it may help control the bladder," said researcher Nima Ghitani, a postdoctoral fellow at the NIH.
For more on urination, head to the U.S. National Library of Medicine.
SOURCE: U.S. National Institutes of Health, news release, Oct. 19, 2020