Real-Time Quaking-Induced Conversion Analysis for the Diagnosis of Sporadic Creutzfeldt-Jakob Disease in Korea

BACKGROUND AND PURPOSE: The level of 14-3-3 protein in the cerebrospinal fluid (CSF) is increased in Creutzfeldt-Jakob disease (CJD) patients, which has led to it being used as a clinical biomarker for the ante-mortem diagnosis of human prion diseases. However, the specificity of the 14-3-3 protein is less reliable for CJD diagnosis. Newly developed assays including real-time quaking-induced conversion (RT-QuIC) have made it possible to detect the PrPSc-like abnormal prion isoform with a high sensitivity in animal and human specimens that might contain a minute amount of PrP(Sc) due to in vitro prion replication. METHODS: This study applied a highly sensitive RT-QuIC assay using recombinant human PrP to detect PrP(Sc) in the CSF of 81 patients with sporadic CJD (sCJD) in Korea. RESULTS: RT-QuIC analysis of the CSF samples based on the expression levels of 14-3-3 and total tau proteins revealed positivity in 62 of 81 sCJD patients (sensitivity of 76.5%) but no positive results in the 100 non-CJD patients. CONCLUSIONS: The sensitivity of the RT-QuIC in this study was similar to that in some previous reports, and the specificity of RT-QuIC was higher than that of 14-3-3 in CSF, suggesting that RT-QuIC analysis can complement the weakness of the specificity of 14-3-3 for the diagnosis of sCJD. These results indicate that RT-QuIC might be very useful for the rapid and specific diagnosis of sCJD and provide a practical novel method for the ante-mortem diagnosis of human prion diseases.

Growth Hormone-Releaser Diet Attenuates Cognitive Dysfunction in Klotho Mutant Mice via Insulin-Like Growth Factor-1 Receptor Activation in a Genetic Aging Model

BACKGROUND: It has been recognized that a defect in klotho gene expression accelerates the degeneration of multiple age-sensitive traits. Accumulating evidence indicates that aging is associated with declines in cognitive function and the activity of growth hormone (GH)/insulin-like growth factor-1 (IGF-1). METHODS: In this study, we examined whether a GH-releaser diet could be effective in protecting against cognitive impairment in klotho mutant mice. RESULTS: The GH-releaser diet significantly induced the expression of IGF-1 and IGF-1 receptors in the hippocampus of klotho mutant mice. Klotho mutant mice showed significant memory impairments as compared with wild-type mice. In addition, the klotho mutation significantly decreased the expression of cell survival/antiapoptotic factors, including phospho-Akt (p-Akt)/phospho-glycogen synthase kinase3beta (p-GSK3beta), phospho-extracellular signal-related kinase (p-ERK), and Bcl-2, but significantly increased those of cell death/proapoptotic factors, such as phospho-c-jun N-terminal kinase (p-JNK), Bax, and cleaved caspase-3 in the hippocampus. Treatment with GH-releaser diet significantly attenuated both decreases in the expression of cell survival/antiapoptotic factors and increases in the expression of cell death/proapoptotic factors in the hippocampus of klotho mutant mice. In addition, klotho mutation-induced oxidative stress was significantly attenuated by the GH-releaser diet. Consequently, a GH-releaser diet significantly improved memory function in the klotho mutant mice. GH-releaser diet-mediated actions were significantly reversed by JB-1, an IGF-1 receptor antagonist. CONCLUSION: The results suggest that a GH-releaser diet attenuates oxidative stress, proapoptotic changes and consequent dysfunction in klotho mutant mice by promoting IGF-1 expression and IGF-1 receptor activation.

Dura Mater Graft-Associated Creutzfeldt-Jakob Disease: The First Case in Korea

Since 1987, dura mater graft-associated iatrogenic Creutzfeldt-Jakob disease (dCJD) has been reported in many countries. We report the first case of dCJD in Korea. A 54-yr-old woman, who underwent resection of the meningioma in the left frontal region and received a dura mater graft 23 yr ago presented with dysesthesia followed by psychiatric symptoms and ataxia. Her neurological symptoms rapidly progressed to such an extent that she exhibited myoclonus, dementia, and pyramidal and extrapyramidal signs within 8 weeks. The 14-3-3 protein was detected in her cerebrospinal fluid; however, an electroencephalogram did not reveal characteristic positive sharp wave complexes. Diffusion-weighted magnetic resonance images, obtained serially over 64 days, revealed the rapid progression of areas of high signal intensity in the caudate nucleus and cingulate gyrus to widespread areas of high signal intensity in the cortex and basal ganglia. Pathological examination of brain biopsy specimens confirmed the presence of spongiform changes and deposition of prion protein in the neurons and neuropils.