Kidneys are often the unsung heroes of maintaining health Blood pressure, filtered 180 liters of fluids and a pound of salt daily to control levels. But new research from University of Pittsburgh geneticists and nephrologists shows that, surprisingly, cellular pathways outside the kidneys are doing some of the heavy lifting when it comes to controlling blood pressure.
The findings, reported today in the Journal of the American Heart Association hypertension points to a promising new target for clinical trials to test the potential of existing drugs to lower blood pressure.
“Our findings were completely unexpected,” said Dr. Brandon Michael Blobner. He did his PhD thesis in Pittsburgh and is now a Bioinformatics Scientist at BlueSphere Bio in Pittsburgh. “There have been some previous indications that mutations in extrarenal salt-handling channels affect blood pressure, but it would have been impossible to confirm this mechanism without the extensive genetic database we have acquired through our interdisciplinary collaboration.”
Nearly half of American adults have high blood pressure or high blood pressure, which is associated with chronic kidney disease and stroke, and it disproportionately affects black individuals. According to the Centers for Disease Control and Prevention, only one in four people has high blood pressure under control, making it one of the largest public health problems in the United States.
High blood pressure is partly caused by an abnormality of fluids and salts, which puts pressure on the walls of arteries and damages blood vessels and organs.
Pitt’s research focuses on the channels or channels that certain cells’ membranes use to regulate fluid volume, based on how much sodium the cells contain . Blobner was curious whether mutations in the gene encoding the channel subunit could affect blood pressure.
Encouraged by Thomas Kleyman, MD, Sheldon Adler Professor of Medicine at Pitt University, Blobner, in collaboration with Dr. Ryan Minster.D., Assistant Professor of Human Genetics at the Pitt School of Public Health, established a dataset of genome sequences and blood pressure recordings of more than 28,000 individuals participating in the Trans-Omics for Precision Medicine (TOPMed) Whole Genome Sequencing Project or Somoan Soifua Manuia Study.
“For me, one of the really exciting things about this project is that it’s so focused and assumption-driven,” the minister said. “Usually with these large genomics projects, we are more agnostic — casting a wide net — where it can take decades to validate a discovery. This project has made major discoveries very quickly.”
Scientists have known that rare mutations exist in the genes encoding the channel’s alpha, beta, and gamma subunits — all three Present in kidney cells – may cause dangerously extreme blood pressure. But when the scientists looked at more subtle mutations, they found that a fourth subunit — delta — affects blood pressure. Importantly, delta is present outside the kidney, in immune cells, and in cells in the lung, heart, and colon.
“I am a nephrologist – I have devoted my entire career to understanding the kidney and its role in maintaining sodium levels moderate blood pressure,” said Kleyman, who also heads the UPMC Renal Electrolytes Division and the study’s senior author. “But our research over the past few years has broadened my focus. This research reinforces the branch we have to go beyond the kidneys to better target blood pressure drugs.”
One of the dangers of some blood pressure medications is that they can lead to high potassium levels, which can be fatal. But the problem is related to poorly functioning kidneys. In theory, if a person’s high blood pressure is due to a fluid and salt imbalance caused by faulty channels in cells outside the kidneys, these drugs could be an effective treatment with less risk of elevated potassium levels.
“At UPMC, one of the things we’re particularly interested in is targeted therapy — you want to give it at the right time Meet the right people,” Kleiman said. “This research may one day help us identify people with specific, subtle genetic mutations that predispose them to a type of high blood pressure that acts outside the kidneys. Knowing this, we can better help that People control their blood pressure.”
Further information: Rare in genes encoding epithelial Na+ channel subunits Variation was associated with blood pressure and renal function, hypertension (2022). www.ahajournals.org/doi/abs/10 … TENSIONAHA.121.18513
Citation: Studying Rare Gene Mutations Bringing Scientists to Surprising Blood Pressure Discovery (Oct. 4, 2022), Retrieved Oct. 17, 2022, from https://medicalxpress.com/news/2022-10-rare-genetic-mutations- scientists-blood.html
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