The discovery was published in the advance online publication of Nature Medicine yesterday.

The team showed that a pro-inflammatory cytokine protein — tumor necrosis factor- α (TNF-α) — disrupts the localization of polycystin 2 (the product of a gene mutated in ADPKD) to the plasma membrane and primary cilia in kidney epithelial cells, thus promoting the formation of cysts.

“The interaction between TNF-α and polycystin in the development of cysts is complicated,” said Xiaogang Li, Ph.D., Senior Research Associate in the Rong Li Lab and first author on the paper. “We believe that this interaction could play a significant role in the transition from normal tubule development to the onset of Polycystic Kidney Disease (PKD) in individuals predisposed for the disease.”

Additionally, the team found that the drug etanercept, an inhibitor of TNF-α currently used to treat rheumatoid arthritis and a number of other conditions, prevents the formation of cysts in the kidneys of mice with ADPKD.

“This discovery is especially exciting because it not only provides insight about the origins of ADPKD, but it also points us toward a drug that we believe shows promise in preventing the development of cysts,” said Rong Li, Ph.D., Investigator and senior author on the publication. “Of course, additional research will be required to test these preliminary results in animal models, but the potential is interesting.”

Currently, no treatments are available to prevent or delay the onset of cysts in people living with PKD. Dialysis and kidney transplants are often required as the disease progresses.

Xiaogang Li received a grant from the PKD Foundation earlier this year. The award of $150,000 over two years supports his efforts to understand the origins of PKD. For more information about PKD or the PKD Foundation, visit www.PKDCure.org. -Stowers Institute for Medical Research