Hippocampal subfields and decline in activities of daily living in Alzheimer's disease and dementia with Lewy bodies
NEURODEGENERATIVE DISEASE MANAGEMENT
Authors: Borda, Miguel German; Jaramillo-Jimenez, Alberto; Tovar-Rios, Diego A.; Ferreira, Daniel; Garcia-Cifuentes, Elkin; Vik-Mo, Audun Osland; Aarsland, Vera; Aarsland, Dag; Oppedal, Ketil
Abstract
Background: Hippocampal atrophy is presented in Alzheimer's disease (AD) and dementia with Lewy bodies (DLB). Cognition, dual-tasks, muscular function, goal-related behaviors and neuropsychiatric symptoms are linked to hippocampal volumes and may lead to functional decline in activities of daily living. We examined the association between baseline hippocampal subfield volumes (HSv) in mild AD and DLB, and functional decline. Materials & methods: 12 HSv were computed from structural magnetic resonance images using Freesurfer 6.0 segmentation. Functional decline was assessed using the rapid disability rating scale score. Linear regressions were conducted. Results: In AD, HSv were smaller bilaterally. However, HSv were not associated with functional decline. Conclusion: Functional decline does not depend on HSv in mild AD and DLB.
Aggregation Propensities of Herpes Simplex Virus-1 Proteins and Derived Peptides: An In Silico and In Vitro Analysis
ACS OMEGA
Authors: Singh, Vikas Kumar; Kumar, Sandeep; Tapryal, Suman
Abstract
Recurrent infections of neurotropic herpes simplex virus-1 (HSV-1) have been implicated in etiology and pathology of Alzheimer's disease (AD). Although protein and peptide aggregation events are at the center of the AD pathophysiology, except a single study where a peptide derived from glycoprotein B of HSV-1 was reported to form beta-amyloid-like aggregates, similar investigations with the entire proteome of HSV-1 have not been attempted. In the current study, 70 HSV-1 proteins were screened using bioinformatics tools to identify aggregation-prone candidates. Thereafter, the 20S proteasome cleavage sites within the sequence of the selected proteins were determined using Pcleavage and NetChop algorithms, thereby mimicking a cellular proteasomal activity providing short peptides. Here, we report the biochemical characterization of a 28-residue-long peptide (HSV-1 gK(208-235)) derived from glycoprotein K of HSV-1. The peptide showed high aggregation propensity and homology to the C-terminus of A beta(1-42) peptide. The aggregates of gK(208-235) peptide were characterized by the Congo red and Thioflavin T assays and Fourier transform infrared (FTIR) spectroscopy, and their spheroid oligomeric structure was established by atomic force microscopy (AFM). Furthermore, the aggregates demonstrated dose-dependent cytotoxicity to primary mouse splenocytes. The current findings hypothesize a mechanism by which HSV-1 may contribute to AD, which may be pursued further in the future.