Prevalence and Clinical Phenotype of Quadruple Misfolded Proteins in Older Adults.

Importance: Quadruple misfolded proteins (tau neurofibrillary tangles, amyloid-ß [Aß], α-synuclein, and transactive response DNA-binding protein 43 [TDP-43]) in the same brain are relatively common in aging. However, the clinical presentation, associated factors, frequency in community-based cohorts, genetic characteristics, and cognitive trajectories associated with the quadruple misfolded proteins phenotype are not well understood. Objective: To describe the quadruple misfolded proteins phenotype, including the trajectories of global cognition, in an autopsy cohort. Design, Setting, and Participants: This retrospective cohort study used brain autopsy data from the University of Kentucky Alzheimer Disease Center (UK-ADC) Brain Bank. Participants were deceased individuals who were enrolled in a longitudinal community-based cohort study of aging and dementia in central Kentucky conducted by the UK-ADC. Included participants were enrolled in the UK-ADC cohort between January 1, 1989, and December 31, 2017; aged 55 years or older at baseline; and followed up for a mean duration of 10.4 years. The participants had Alzheimer disease pathology (tau and Aß), α-synuclein, and TDP-43 data, along with Braak neurofibrillary tangle stage I to VI. Data analysis was conducted between February 1, 2019, and September 30, 2019. Main Outcomes and Measures: Frequency of quadruple misfolded proteins was estimated, and proteinopathy group characteristics and associations with global cognition were evaluated. Multinomial logistic regression was used to estimate the association of proteinopathy group with participant characteristics, including age at death, sex, and apolipoprotein ε4 (APOE ε4) allele. Generalized estimating equations were used to estimate the probability of obtaining Mini-Mental State Examination (MMSE) scores within the normal cognition (27-30 points) and severe impairment (≤13 points) ranges during the 12 years before death. Results: The final sample included 375 individuals (mean [SD] age at death, 86.9 [8.0] years); 232 women [61.9%]). Quadruple misfolded proteins were detected in 41 of 214 individuals with dementia (19.2%). Overall, 46 individuals (12.3%) had quadruple misfolded proteins, whereas 143 individuals (38.1%) had 3 proteinopathies. Dementia frequency was highest among those with quadruple misfolded proteins (41 [89.1%]), and participants with quadruple misfolded proteins had the lowest final mean (SD) MMSE scores of 13.4 (9.8) points. Adjusting for age at death and sex, the APOE ε4 allele was associated with higher odds of quadruple misfolded proteins (adjusted odds ratio, 2.55; 95% CI, 1.16- 5.62; P = .02). The quadruple misfolded proteins group had both the lowest probability of obtaining MMSE scores in the normal cognition range, even 12 years before death, and the highest probability of having MMSE scores in the severe impairment range. Conclusions and Relevance: Quadruple misfolded proteins appear to be a common substrate for cognitive impairment and to be associated with an aggressive course of disease that typically ends with severe dementia. The prevalence of comorbid α-synuclein and TDP-43 with Alzheimer disease pathology (tau and Aß) may complicate efforts to identify therapies to treat and prevent Alzheimer disease.

Association of Aggresomes with Survival Outcomes in Pediatric Medulloblastoma.

Aggresomes are inclusion bodies for misfolded/aggregated proteins. Despite the role of misfolded/aggregated proteins in neurological disorders, their role in cancer pathogenesis is poorly defined. In the current study we aimed to investigate whether aggresomes-positivity could be used to improve the disease subclassification and prognosis prediction of pediatric medulloblastoma. Ninety three pediatric medulloblastoma tumor samples were retrospectively stratified into three molecular subgroups; WNT, SHH and non-WNT/non-SHH, using immunohistochemistry and Multiplex Ligation Probe Amplification. Formation of aggresomes were detected using immunohistochemistry. Overall survival (OS) and event-free survival (EFS) were determined according to risk stratification criteria. Multivariate Cox regression analyses were carried out to exclude confounders. Aggresomes formation was detected in 63.4% (n = 59/93) of samples. Aggresomes were non-randomly distributed among different molecular subgroups (P = 0.00002). Multivariate Cox model identified aggresomes' percentage at ≥20% to be significantly correlated with patient outcome in both OS (HR = 3.419; 95% CI, 1.30-8.93; P = 0.01) and EFS (HR = 3; 95% CI, 1.19-7.53; P = 0.02). The presence of aggresomes in ≥20% of the tumor identified poor responders in standard risk patients; OS (P = 0.02) and EFS (P = 0.06), and significantly correlated with poor outcome in non-WNT/non-SHH molecular subgroup; OS (P = 0.0002) and EFS (P = 0.0004).

The natural history of idiopathic autonomic failure: The IAF-BO cohort study.

OBJECTIVE: To retrospectively describe clinical and instrumental features of a cohort of patients with at least a 5-year history of idiopathic autonomic failure (IAF) longitudinally evaluated at the Autonomic Unit of the University of Bologna (IAF-Bo cohort). METHODS: We identified patients with at least a 5-year history of IAF who were referred to our department from 1989 to 2016 and evaluated at least once a year during the disease course. Clinical and instrumental data were collected from medical records. Clinical variables were categorized as early if presenting within 3 years from disease onset. Predictors associated with conversion to other synucleinopathies were identified in a Cox regression analysis. RESULTS: The IAF-Bo cohort included 50 patients (39 male, 19 deceased at the last follow-up). At the last follow-up visit, 34 patients retained IAF phenotype (ncIAF group), while 16 developed a CNS synucleinopathy (converters group). Specific clinical and instrumental features were represented differently in the converters and ncIAF groups. The converters group showed a higher risk of death than the ncIAF group. Early onset of urinary dysfunction, early onset of REM sleep behavior disorder, and a Valsalva ratio ≥1.25 were identified as variables associated with phenoconversion. CONCLUSIONS: This is one of the largest studies on the natural history of a cohort of patients with at least a 5-year history of IAF, showing a percentage of phenoconversion of 32%. We demonstrated that specific clinical and instrumental features entail an increased probability of phenoconversion. These findings could contribute to a better definition of the nature of IAF and to the identification of early markers of phenoconversion.

Emerging novel concept of chaperone therapies for protein misfolding diseases.

Chaperone therapy is a newly developed molecular therapeutic approach to protein misfolding diseases. Among them we found unstable mutant enzyme proteins in a few lysosomal diseases, resulting in rapid intracellular degradation and loss of function. Active-site binding low molecular competitive inhibitors (chemical chaperones) paradoxically stabilized and enhanced the enzyme activity in somatic cells by correction of the misfolding of enzyme protein. They reached the brain through the blood-brain barrier after oral administration, and corrected pathophysiology of the disease. In addition to these inhibitory chaperones, non-competitive chaperones without inhibitory bioactivity are being developed. Furthermore molecular chaperone therapy utilizing the heat shock protein and other chaperone proteins induced by small molecules has been experimentally tried to handle abnormally accumulated proteins as a new approach particularly to neurodegenerative diseases. These three types of chaperones are promising candidates for various types of diseases, genetic or non-genetic, and neurological or non-neurological, in addition to lysosomal diseases.