title: Klotho in the cerebrospinal fluid of adults with and without Alzheimer's disease.
abstract: The aging-suppressor gene klotho encodes a single-pass transmembrane protein that is predominantly secreted by the choroid plexus of the brain and in the kidney. Klotho-deficient mice develop multiple aging phenotypes, including impaired cognition. Klotho concentrations have not been described in the CSF of humans. We measured klotho in the CSF of 20 older adults with Alzheimer's disease and in 20 older and 20 younger adults with normal cognition. In 10 adults, aged 38-87 years, CSF klotho measurements were made at baseline and every 6h up to 18-30 h later. Mean (95% confidence interval [C.I.]) CSF klotho in men versus women were 899 (814, 983) and 716 (632, 801) pg/mL, respectively (P=0.002). Mean (95% C.I.) CSF klotho in older adults with and without Alzheimer's disease were 664 (603, 725) and 776 (705, 828) pg/mL, respectively (P=0.02), adjusting for sex. Mean (95% C.I.) klotho in older versus younger adults were 766 (658, 874) and 992 (884, 1100) pg/mL, respectively (P=0.005), adjusting for sex. In the longitudinal study of CSF klotho, no significant circadian fluctuations were found in CSF klotho levels. This study suggests that CSF klotho concentrations are lower in females compared with males, in Alzheimer's disease, and in older versus younger adults.
authors.affiliation: Johns Hopkins University School of Medicine, Baltimore, MD 21287, United States. Electronic address: rdsemba@jhmi.edu.
authors.forename: Richard D
authors.initials: RD
authors.lastname: Semba
authors.affiliation: Johns Hopkins University School of Medicine, Baltimore, MD 21287, United States.
authors.forename: Abhay R
authors.initials: AR
authors.lastname: Moghekar
authors.affiliation: Johns Hopkins University School of Medicine, Baltimore, MD 21287, United States.
authors.forename: Jason
authors.initials: J
authors.lastname: Hu
authors.affiliation: Johns Hopkins University School of Medicine, Baltimore, MD 21287, United States.
authors.forename: Kai
authors.initials: K
authors.lastname: Sun
authors.affiliation: Johns Hopkins University School of Medicine, Baltimore, MD 21287, United States.
authors.forename: Randi
authors.initials: R
authors.lastname: Turner
authors.affiliation: National Institute on Aging, National Institutes of Health, Baltimore, MD, USA.
authors.forename: Luigi
authors.initials: L
authors.lastname: Ferrucci
authors.affiliation: Johns Hopkins University School of Medicine, Baltimore, MD 21287, United States.
authors.forename: Richard
authors.initials: R
authors.lastname: O'Brien
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000134:cerebrospinal fluid*; D016022:Case-Control Studies; D005260:Female; D005966:Glucuronidase / Q000134:cerebrospinal fluid*; D006801:Humans; D006849:Hydrocephalus / Q000134:cerebrospinal fluid; D000090265:Klotho Proteins; D008297:Male; D012737:Sex Factors
chemical_list: D005966:Glucuronidase; D000090265:Klotho Proteins
keywords: Aging; Alzheimer's disease; Brain; Cerebrospinal fluid; Klotho