"This study shows the importance of genes that regulate the multiple aging processes involved in the maintenance of cognitive function," said Suzana Petanceska, Ph.D., program director in NIA's Division of Neuroscience. "Understanding the factors that control the levels and activity of KLOTHO across multiple organ systems may open new therapeutic avenues for prevention of age-related cognitive decline and dementia."
The investigators tested a variety of cognitive skills, including learning, memory, and attention. More than 700 subjects, 52 to 85 years old were tested as part of three studies. None had any sign of dementia. Consistent with previous studies, 20 to 25 percent of the subjects had one copy of the KL-VS variant and performed better on the tests than those who had no copies. Performance on the tests decreased with age regardless of whether a subject had one or no copies of the KL-VS gene variant.
The KLOTHO gene provides the blueprint for a protein made primarily by the cells of the kidney, placenta, small intestine, and prostate. A shortened version of the protein can circulate through the blood system. Blood tests showed that subjects who had one copy of the KL-VS variant also had higher levels of circulating klotho protein. The levels decreased with age as others have observed. The researchers speculate that the age-related decrease in circulating levels of klotho protein may have caused some of the decline in performance on the cognitive tests.
"These surprising results pave a promising new avenue of research," said Roderick Corriveau, Ph.D., program director at NIH's National Institute of Neurological Disorders and Stroke (NINDS). "Although preliminary, they suggest that a form of klotho could be used to enhance cognition for people suffering from dementia."
To test this idea the researchers genetically engineered mice to overproduce klotho protein. The klo
|Contact: Christopher G. Thomas|
NIH/National Institute of Neurological Disorders and Stroke