Amplification of distinct α-synuclein fibril conformers through protein misfolding cyclic amplification

Amyloid fibril formation has been implicated in the pathogenesis of neurodegenerative diseases. Fibrillation generates numerous conformers. Presumably, the conformers may possess specific biological properties, thus providing a biochemical framework for strains of prions. However, the precise relationship between various fibril conformers and their pathogenic functions has not been determined because of limited accessibility to adequate amounts of fibrils from tissue samples. α-Synuclein is one such protein, and it has been implicated in Parkinson disease. Using a technique known as protein misfolding cyclic amplification, originally developed for amplifying prions, we established a procedure through which the amplification of α-synuclein fibrils is possible. With a trace amount of seeds, we succeeded in amplifying α-synuclein fibrils. The replication of the seeds was faithful in terms of conformation even after multiple rounds of cyclic amplification. Moreover, two transgenic mouse strains each representing a distinct synucleinopathy were used to investigate different conformers by using this technique. The amplified α-synuclein fibrils derived from the tissue extracts of these two strains led to the production of two different fibril conformers with distinct proteinase K digestion profiles. Together, our results demonstrated that a trace amount of α-synuclein fibrils in tissue extracts could be amplified with their conformations conserved. This procedure should be useful in amplifying α-synuclein fibrils from the brains and body fluids of patients afflicted with synucleinopathies and may serve as a potential diagnostic tool for Parkinson disease and other synucleinopathies.

Sarcopenia Is Not Associated with Depression in Korean Adults: Results from the 2010-2011 Korean National Health and Nutrition Examination Survey / 가정의학회지

BACKGROUND: Sarcopenia is associated with metabolic disorders, cardiovascular disease, and mortality; however, its association with depression in the general population remains unknown. Therefore, we investigated this association in Korea. METHODS: This study included 8,958 and 8,518 subjects from the 2010-2011 Korean National Health and Nutrition Examination Survey V-1, 2. The study was restricted to participants > or =20 years of age who had completed the survey, including whole-body dual-energy X-ray absorptiometry scans. After exclusion, 7,364 subjects were included in our final analysis. Age was categorized into three groups (20-39, 40-59, and > or =60 years), and subjects were categorized according to their sarcopenic and obesity status. Depression was categorized into three groups (not depressed, depressed, and depression). RESULTS: The sarcopenia group did not have a higher prevalence of depression or depressive symptoms compared to the nonsarcopenia group; the same was true even when obesity was considered. All age groups showed non-significant associations between sarcopenia and depression. In multivariate logistic regression models, no significant associations were observed between sarcopenia and prevalence of depression or depressed symptoms in men and women. CONCLUSION: We found no associations between sarcopenia and the prevalence of depression or depressed symptoms in Korean adults. Future large prospective studies and randomized controlled trials are needed to further assess this relationship.

Corrigendum: Loss of glucocerebrosidase 1 activity causes lysosomal dysfunction and alpha-synuclein aggregation

The authors have noticed an error in publication of this paper.

Loss of glucocerebrosidase 1 activity causes lysosomal dysfunction and alpha-synuclein aggregation

Lysosomal dysfunction is a common pathological feature of neurodegenerative diseases. GTP-binding protein type A1 (GBA1) encodes beta-glucocerebrosidase 1 (GCase 1), a lysosomal hydrolase. Homozygous mutations in GBA1 cause Gaucher disease, the most common lysosomal storage disease, while heterozygous mutations are strong risk factors for Parkinson's disease. However, whether loss of GCase 1 activity is sufficient for lysosomal dysfunction has not been clearly determined. Here, we generated human neuroblastoma cell lines with nonsense mutations in the GBA1 gene using zinc-finger nucleases. Depending on the site of mutation, GCase 1 activity was lost or maintained. The cell line with GCase 1 deficiency showed indications of lysosomal dysfunction, such as accumulation of lysosomal substrates, reduced dextran degradation and accumulation of enlarged vacuolar structures. In contrast, the cell line with C-terminal truncation of GCase 1 but with intact GCase 1 activity showed normal lysosomal function. When alpha-synuclein was overexpressed, accumulation and secretion of insoluble aggregates increased in cells with GCase 1 deficiency but did not change in mutant cells with normal GCase 1 activity. These results demonstrate that loss of GCase 1 activity is sufficient to cause lysosomal dysfunction and accumulation of alpha-synuclein aggregates.

ATP13A2/PARK9 Deficiency Neither Cause Lysosomal Impairment Nor Alter alpha-Synuclein Metabolism in SH-SY5Y Cells

Parkinson's disease is a multifactorial disorder with several genes linked to the familial types of the disease. ATP13A2 is one of those genes and encode for a transmembrane protein localized in lysosomes and late endosomes. Previous studies suggested the roles of this protein in lysosomal functions and cellular ion homeostasis. Here, we set out to investigate the role of ATP13A2 in lysosomal function and in metabolism of alpha-synuclein, another PD-linked protein whose accumulation is implicated in the pathogenesis. We generated non-sense mutations in both copies of ATP13A2 gene in SH-SY5Y human neuroblastoma cells. We examined lysosomal function of ATP13A2-/- cells by measuring the accumulation of lysosomal substrate proteins, such as p62 and polyubiquitinated proteins, induction of acidic compartments, and degradation of ectopically introduced dextran. None of these measures were altered by ATP13A2 deficiency. The steady-state levels of alpha-synuclein in cells or secretion of this protein were unaltered either in ATP13A2-/- compared to the normal cells. Therefore, the proposed roles of ATP13A2 in lysosomal functions may not be generalized and may depend on the cellular context. The ATP13A2-/- cells generated in the current study may provide a useful control for studies on the roles of PD genes in lysosomal functions.

Retinal Damage in Chloroquine Maculopathy, Revealed by High Resolution Imaging: A Case Report Utilizing Adaptive Optics Scanning Laser Ophthalmoscopy

A 53-year-old Asian woman was treated with hydroxychloroquine and chloroquine for lupus erythematosus. Within a few years, she noticed circle-shaped shadows in her central vision. Upon examination, the patient's visual acuity was 20 / 25 in both eyes. Humphrey visual field (HVF) testing revealed a central visual defect, and fundoscopy showed a ring-shaped area of parafoveal retinal pigment epithelium depigmentation. Fundus autofluorescence imaging showed a hypofluorescent lesion consistent with bull's eye retinopathy. Adaptive optics scanning laser ophthalmoscope (AO-SLO) revealed patch cone mosaic lesions, in which cones were missing or lost. In addition, the remaining cones consisted of asymmetrical shapes and sizes that varied in brightness. Unlike previous studies employing deformable mirrors for wavefront aberration correction, our AO-SLO approach utilized dual liquid crystal on silicon spatial light modulators. Thus, by using AO-SLO, we were able to create a photographic montage consisting of high quality images. Disrupted cone AO-SLO images were matched with visual field test results and functional deficits were associated with a precise location on the montage, which allowed correlation of histological findings with functional changes determined by HVF. We also investigated whether adaptive optics imaging was more sensitive to anatomical changes compared with spectral-domain optical coherence tomography.

Retinal Damage in Chloroquine Maculopathy, Revealed by High Resolution Imaging: A Case Report Utilizing Adaptive Optics Scanning Laser Ophthalmoscopy

A 53-year-old Asian woman was treated with hydroxychloroquine and chloroquine for lupus erythematosus. Within a few years, she noticed circle-shaped shadows in her central vision. Upon examination, the patient's visual acuity was 20 / 25 in both eyes. Humphrey visual field (HVF) testing revealed a central visual defect, and fundoscopy showed a ring-shaped area of parafoveal retinal pigment epithelium depigmentation. Fundus autofluorescence imaging showed a hypofluorescent lesion consistent with bull's eye retinopathy. Adaptive optics scanning laser ophthalmoscope (AO-SLO) revealed patch cone mosaic lesions, in which cones were missing or lost. In addition, the remaining cones consisted of asymmetrical shapes and sizes that varied in brightness. Unlike previous studies employing deformable mirrors for wavefront aberration correction, our AO-SLO approach utilized dual liquid crystal on silicon spatial light modulators. Thus, by using AO-SLO, we were able to create a photographic montage consisting of high quality images. Disrupted cone AO-SLO images were matched with visual field test results and functional deficits were associated with a precise location on the montage, which allowed correlation of histological findings with functional changes determined by HVF. We also investigated whether adaptive optics imaging was more sensitive to anatomical changes compared with spectral-domain optical coherence tomography.

A Case of Oliguric Mannitol Induced Acute Kidney Injury Early Treated by Continuous Renal Replacement Therapy / 고신대학교의과대학학술지

We report oliguric mannitol-induced acute kidney injury (AKI) early treated by continuous renal replacement therapy. A 70-year-old woman was admitted to the Department of Neurology with diagnosis of acute intracranial hemorrhage. Mannitol was infused for intracranial pressure control. At admission third day, urine output was abruptly decreased to 57 ml during first 6 hours and blood urea nitrogen (BUN) and serum creatinine was increased to 54.2 mg/dL and 5.3 mg/dL respectively. Plasma osmolality was 340 mOsm/kg and osmolar gap was 70. Mannitol was immediately withdrawn and continuous renal replacement therapy (CRRT) was performed to remove mannitol rapidly. Urine output was increased 6 hours later after continuous veno-veno hemodiafiltration (CVVHDF) start. BUN and creatinine was decreased to 21.4 and 1.2 mg/dL at admission ninth day. Mannitol can develop oliguric AKI and CRRT may be of more benefit than conventional hemodialysis in the case of increased intracranial pressure.

Diagnostic Abilities to Detect Glaucomatous Abnormality Using Normal Retinal Thickness Measured by Optical Coherence Tomography

PURPOSE: Recently, the introduction of spectral-domain optical coherence tomography (SD-OCT) has enabled measurement of retinal thickness in the posterior pole in 64 sectors. SD-OCT was used to evaluate the diagnostic effectiveness in detecting glaucomatous abnormality of visual field sensitivity. A normal value for retinal thickness was determined and then compared in corresponding local sectors. METHODS: Thirty healthy controls and 30 glaucoma subjects were evaluated. Macular thickness values from the 4 adjacent square cells in an 8 x 8 posterior pole retinal thickness map were averaged for a mean retinal thickness (MRT) value. A normative database was prepared using the data from the healthy eyes of this study to determine the diagnostic criteria for MRT. If the MRT value was <5% (Criteria A) or <1% (Criteria B) of the normative database, it was considered to be abnormal. The abnormalities of the MRT value for each diagnostic criteria were compared with the visual field sensitivity results in the corresponding positions. RESULTS: The concordance of abnormalities between MRT and visual field sensitivity at 16 measured points was low in both criteria A (Kappa value; -0.418~0.429) and B (Kappa value; -0.363~0.444). Based on the results of the visual field at each focal point, the sensitivities and specificities of MRT values using the 2 criteria ranged from 0% to 100%. CONCLUSIONS: In this study, MRT values showed low correlation and diagnostic ability to detect decreased sensitivity of the visual field in corresponding points, when customized criteria derived from a normative database were applied.

Changes of Peripapillary Retinal Nerve Fiber Layer Thickness Profile According to Aging in Myopic Eyes

PURPOSE: To evaluate the effects of age on the distributional variability of peripapillary retinal nerve fiber layer (RFNL) thickness measured by optical coherence tomography (OCT) in myopia. METHODS: Only the right eye of 64 myopic patients with long axial length (> or =24.5 mm) was included in the present study. The patients were divided into 2 age groups, 20 to 39 years of age and 40 to 59 years of age. Eventually, 42 subjects were selected and matched based on the difference of axial length not exceeding 0.5 mm between subjects in each group. The RFNL thickness was measured using Stratus OCT and average thickness, angular locations of double humps, and false-positive rate were compared. RESULTS: In both groups, the distribution of RNFL thickness in a double hump pattern was observed, which had a deviation to the temporal side only in the younger myopic eye group, but not in the middle-aged group. The middle-aged group had significantly thinner RNFL in 1, 7, and 8 clock-hour sectors compared to the younger myopic eyes (p < or = 0.02). Probability of abnormal OCT parameters at the 5% level of the 2 groups with the built-in RNFL normative database was not significantly different. CONCLUSIONS: The variability of RFNL thickness distribution related to axial length was less observed in the middle-aged group than the younger-aged group. These results should be considered in glaucoma diagnosis when using OCT.

A Case of Bacillus licheniformis Spondylitis and Bacteremia in a Patient with Lung Cancer

Bacillus licheniformis is an aerobic, gram-positive, spore-forming rod bacteria usually found in the environment. Infections with B. licheniformis are rare and usually associated with an immunocompromised state, trauma, and an indwelling catheter. We report a case of bacteremic B. licheniformis spondylitis following vertebroplasty in a patient with lung cancer.

Mutational Analysis of the NF1 Gene in Two Families with Neurofibromatosis 1 Accompanied by Pheochromocytoma

Neurofibromatosis type 1 (NF1) is one of the most common autosomal dominant inherited disorders affecting the nervous system. NF1 is associated with mutations in the NF1 gene, which is located on chromosome sub-band 17q11.2 and contains 57 exons spanning approximately 300 kb of genomic DNA. NF1 is caused by a loss of function mutation of the NF1 gene, a tumor suppressor gene, which encodes for neurofibromin, a GTPase-activating protein (GAP) involved in the negative regulation of Ras activity. The GAP-related domain, which is encoded for by exons 20-27a, is one of the most important functional domains in neurofibromin. The cysteine-serine-rich domain has been recognized as an important functional domain in NF1-related pheochromocytomas. As the result of many genetic analyses of NF1-related pheochromocytomas, pheochromocytoma has generally been recognized as a true component of NF1. We recently experienced two families with NF1 accompanied by pheochromocytoma. The proband of family 1 is a 31-year-old female diagnosed with NF1 and pheochromocytoma. Gene analysis of the proband and her sister showed that the mutation of the NF1 gene (c.7907+1G>A) led to the skipping of exon 53 during NF1 mRNA splicing. The proband of family 2 is a 48-year-old male who was diagnosed with the same condition. Gene analysis demonstrated the mutation of the NF1 gene (c.5206-8C>G) with missplicing of exon 37. These novel germline mutations did not fall into the GAP-related nor the cysteine-serine-rich domains, but into the C-terminal area of the NF1 gene. This suggests that the correlation between the genotype and phenotype of NF1-related pheochromocytoma is somewhat difficult to characterize. Further studies will be necessary to confirm the function of the C-terminal area of the NF1 gene and its contribution to the development of NF1 and pheochromocytoma.

Influence of Stomach Cancer Risk Factors on the Development of Gastric Dysplasia

BACKGROUND: Both atrophic gastritis and intestinal metaplasia may progress to gastric dysplasia. This study aimed to analyze the factors influencing progression of atrophic gastritis and intestinal metaplasia to dysplasia. METHODS: People diagnosed with atrophic gastritis and intestinal metaplasia for the first time received a follow-up endoscopy and were investigated for the cumulative incidence rate of gastric dysplasia by age, gender, smoking habit, alcohol intake, rice consumption and family history of stomach cancer. RESULTS: The cumulative incidence rate increased with age, consuming > or =3 bowls of rice per day and family history of stomach cancer. Multivariate analysis showed that the cumulative incidence rate of gastric dysplasia increased in subjects >61 years (RR=2.54, P=0.014), in those consuming > or =3 bowls of rice per day (RR=1.46, P=0.021) and in those with a family history of stomach cancer (RR=1.31, P=0.037). CONCLUSIONS: More active management, such as intensive endoscopic follow-up examinations, lifestyle change and education regarding gastric dysplasia, are required in those older than 61 years, having a higher intake of grain or with a family history of stomach cancer.

Glomerular Filtration Rate Difference between Renal Cyst Group and Control Group / 가정의학회지

BACKGROUND: The simple renal cyst is the most prevalent cystic deformation in adults and is most of them are incidentally found during medical examination. In this study, the clinical differences were compared between simple renal cyst and control groups diagnosed by abdominal ultrasonography during periodic medical examination. METHODS: We randomly selected 2,277 persons who took medical examination in one general hospital health promotion center. Among them, analysis was conducted for 188 subjects with simple renal cyst and 188 subjects without renal cyst whose sex, age, and body mass index were matched. Renal cyst subjects were compared with control group to search for their relationship with hypertension, renal function and microscopic hematuria, past medical history, social history, results of other abdominal ultrasonography findings, urine test, and blood test. RESULTS: Among 2,213 subjects, simple renal cyst was found in 188 subjects (8.5%). The subjects who had more than three simple renal cysts were significant older (P = 0.05) and the oldest age was 70's. Also, higher hypertension prevalence (P = 0.05), more microscopic hematuria, higher serum creatinine (P = 0.02), and lower glomerular filtration rate (P < 0.01) were observed in simple renal cyst group. CONCLUSION: It is needed to survey size, shape and change of simple renal cyst using abdominal ultrasonography as well as how its progression may be related to developing hypertension, decreased renal function and microscopic hematuria.