TUESDAY, April 24 (HealthDay News) -- A gene previously linked to an increased risk of developing kidney stones is part of a calcium-sensitive pathway that regulates calcium absorption in the kidney, according to a study in the April 18 issue of The EMBO Journal.
Yongfeng Gong, Ph.D., from Washington University in St. Louis, and colleagues examined the expression, regulation, and function of the claudin-14 gene in the kidney. Claudins are a family of paracellular channels that allow selective permeation of ions through the epithelial tight junction, they note.
The researchers found that claudin-14 was expressed in the thick ascending limb (TAL) of Henle. Expression was suppressed by two microRNAs under normal dietary conditions, but was increased by a diet high in calcium. Claudin-14 blocked a paracellular cation channel critical for calcium reabsorption in the TAL. Mice lacking claudin-14 developed hypermagnesemia, hypomagnesiuria, and hypocalciuria when fed a high calcium diet.
"Many genes likely play a role in the formation of kidney stones," a study coauthor said in a statement. "But this study gives us a better idea of the way one of the major players work. Now that we understand the physiology of the condition, we can start to think about better treatments or even ways to prevent stones from developing in the first place."
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