AUGUSTA, Ga. A class of drugs widely used to treat osteoporosis appears to impede a cell's ability to repair a protective outer membrane that helps determine what enters and exits, researchers report.
The inability to quickly repair a membrane is lethal to a cell and may help explain the rare and serious side effect of jawbone destruction that can occur following dental work in patients taking these drugs, said Caroline Lewis, a sophomore at the Medical College of Georgia at Georgia Regents University.
"The bottom line is it inhibits cell membrane repair in two distinct cell types," Lewis said. She is among five winners of the 2014 National Medical Students Competition of the American College of Physicians. Lewis presented her work April 12 during the college's Internal Medicine 2014 meeting in Orlando.
Working in the lab of Dr. Paul McNeil, an MCG cell biologist specializing in cell membrane repair, Lewis found that kidney epithelial cells from monkeys and muscle cells from mice both lost their ability to quickly repair their outer membrane after exposure to zoledronate, a commonly used bisphosphonate, Lewis said. Without drug exposure, cells quickly recovered from a microscope laser injury.
"That is healthy, normal repair," she said, citing a video showing the normal cell experiencing only a brief flicker of fluorescence where hit by a laser. On the other hand, zoledronate-exposed cells quickly filled with a fluorescent dye the researchers placed in the petry dish.
"All this dye coming into the cell means there is still a disruption and no repair occurred to sort of mend the fence," Lewis said. "We know these cells are dying, Basically these videos speak for themselves."
"It's a paradox," added McNeil. "On the one hand, (the drug) is given to people mainly to promote bone health, increase bone density. But in the case of a jaw that has suffered, for example, a tooth extraction, the exact opposi
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Medical College of Georgia at Georgia Regents University