23 research outputs found
Identification of <em>CHIP</em> as a novel causative gene for autosomal recessive cerebellar ataxia
Autosomal recessive cerebellar ataxias are a group of neurodegenerative disorders that are characterized by complex clinical and genetic heterogeneity. Although more than 20 disease-causing genes have been identified, many patients are still currently without a molecular diagnosis. In a two-generation autosomal recessive cerebellar ataxia family, we mapped a linkage to a minimal candidate region on chromosome 16p13.3 flanked by single-nucleotide polymorphism markers rs11248850 and rs1218762. By combining the defined linkage region with the whole-exome sequencing results, we identified a homozygous mutation (c.493CT) in CHIP (NM_005861) in this family. Using Sanger sequencing, we also identified two compound heterozygous mutations (c.389AT/c.441GT; c.621C>G/c.707GC) in CHIP gene in two additional kindreds. These mutations co-segregated exactly with the disease in these families and were not observed in 500 control subjects with matched ancestry. CHIP colocalized with NR2A, a subunit of the N-methyl-D-aspartate receptor, in the cerebellum, pons, medulla oblongata, hippocampus and cerebral cortex. Wild-type, but not disease-associated mutant CHIPs promoted the degradation of NR2A, which may underlie the pathogenesis of ataxia. In conclusion, using a combination of whole-exome sequencing and linkage analysis, we identified CHIP, encoding a U-box containing ubiquitin E3 ligase, as a novel causative gene for autosomal recessive cerebellar ataxia
Computer-assisted lip diagnosis on traditional Chinese medicine using multi-class support vector machines
Atomistic Characterization of Binding Modes and Affinity of Peptide Inhibitors to Amyloid-beta Protein
The aggregation of amyloid beta-protein (A beta) is tightly linked to the pathogenesis of Alzheimer\u27s disease. Previous studies have found that three peptide inhibitors (i.e., KLVFF, VVIA, and LPFFD) can inhibit A beta aggregation and alleviate A beta-induced neurotoxicity. However, atomic details of binding modes and binding affinities between these peptide inhibitors and A beta have not been revealed. Here, using molecular dynamics simulations and molecular mechanics Poisson Boltzmann surface area (MM/PBSA) analysis, we examined the effect of three peptide inhibitors (KLVFF, VVIA, and LPFFD) on their sequence-specific interactions with A beta and the molecular basis of their inhibition. All inhibitors exhibit varied binding affinity to A beta, in which KLVFF has the highest binding affinity, whereas LPFFD has the least. MM/PBSA analysis further revealed that different peptide inhibitors have different modes of interaction with A beta, consequently hotspot binding residues, and underlying driving forces. Specific residue-based interactions between inhibitors and A beta were determined and compared for illustrating different binding and inhibition mechanisms. This work provides structure-based binding information for further modification and optimization of these three peptide inhibitors to enhance their binding and inhibitory abilities against A beta aggregation
Hematoxylin Inhibits Amyloid β‑Protein Fibrillation and Alleviates Amyloid-Induced Cytotoxicity
Accumulation and
aggregation of amyloid β-protein (Aβ)
play an important role in the pathogenesis of Alzheimer’s disease.
There has been increased interest in finding new anti-amyloidogenic
compounds to inhibit Aβ aggregation. Herein, thioflavin T fluorescent
assay and transmission electron microscopy results showed that hematoxylin,
a natural organic molecule extracted from <i>Caesalpinia sappan</i>, was a powerful inhibitor of Aβ42 fibrillogenesis. Circular
dichroism studies revealed hematoxylin reduced the β-sheet content
of Aβ42 and made it assemble into antiparallel arrangement,
which induced Aβ42 to form off-pathway aggregates. As a result,
hematoxylin greatly alleviated Aβ42-induced cytotoxicity. Molecular
dynamics simulations revealed the detailed interactions between hematoxylin
and Aβ42. Four binding sites of hematoxylin on Aβ42 hexamer
were identified, including the N-terminal region, S8GY10 region, turn
region, and C-terminal region. Notably, abundant hydroxyl groups made
hematoxylin prefer to interact with Aβ42 via hydrogen bonds.
This also contributed to the formation of π–π stacking
and hydrophobic interactions. Taken together, the research proved
that hematoxylin was a potential agent against Aβ fibrillogenesis
and cytotoxicity
Elevated expression of thyroid hormone receptor-interacting protein 13 drives tumorigenesis and affects clinical outcome
Latent Structure Analysis and Syndrome Differentiation for the Integration of Traditional Chinese and Western Medicine (II): Joint Clustering
9-Methylfascaplysin Is a More Potent Aβ Aggregation Inhibitor than the Marine-Derived Alkaloid, Fascaplysin, and Produces Nanomolar Neuroprotective Effects in SH-SY5Y Cells
5-Hydroxycyclopenicillone Inhibits β-Amyloid Oligomerization and Produces Anti-β-Amyloid Neuroprotective Effects In Vitro
The oligomer of β-amyloid (Aβ) is considered the main neurotoxin in Alzheimer’s disease (AD). Therefore, the inhibition of the formation of Aβ oligomer could be a target for AD therapy. In this study, with the help of the dot blotting assay and transmission electronic microscopy, it was have discovered that 5-hydroxycyclopenicillone, a cyclopentenone recently isolated from a sponge-associated fungus, effectively reduced the formation of Aβ oligomer from Aβ peptide in vitro. Molecular dynamics simulations suggested hydrophobic interactions between 5-hydroxycyclopenicillone and Aβ peptide, which might prevent the conformational transition and oligomerization of Aβ peptide. Moreover, Aβ oligomer pre-incubated with 5-hydroxycyclopenicillone was less toxic when added to neuronal SH-SY5Y cells compared to the normal Aβ oligomer. Although 5-hydroxycyclopenicillone is not bioavailable in the brain in its current form, further modification or encapsulation of this chemical might improve the penetration of 5-hydroxycyclopenicillone into the brain. Based on the current findings and the anti-oxidative stress properties of 5-hydroxycyclopenicillone, it is suggested that 5-hydroxycyclopenicillone may have potential therapeutic efficacy in treating AD