Discovery of a tetracyclic indole alkaloid that postpones fibrillation of hen egg white lysozyme protein.

Protein aggregation, such as amyloid fibril formation, is molecular hallmark of many neurodegenerative disorders including Alzheimer's, Parkinson's, and Prion disease. Indole alkaloids are well-known as the compounds having the ability to inhibit protein fibrillation. In this study, we experimentally and computationally have investigated the anti-amyloid property of a derivative of a synthesized tetracyclic indole alkaloid (TCIA), possessing capable functional groups. The fibrillation reaction of Hen White Egg Lysozyme (HEWL) was performed in absence and presence of the indole alkaloid. For quantitative analysis, we used Thioflovin T binding assay which showed ~50% reduction in fibril formation in the presence of 20 µM TCIA. Using TEM imaging, we observed a significant morphological change in our model protein in the presence of TCIA. In addition, we exploited FT-IR assay by which Amide I peak's shifting toward lower wavenumber was clearly observed. Using Molecular Docking, the interaction of the inhibitor (TCIA) with the protein's amyloidogenic region was modeled. Also, different biophysical parameters were calculated by Molecular Dynamics (MD) simulation. Various biochemical assays, conformational change, and hydrophobicity exposure of the protein during amyloid formation indicated that the compound assists HEWL to keep its native structure via destabilizing ß-sheet structure.

Review on Alzheimer's disease: Inhibition of amyloid beta and tau tangle formation.

It is reported that approximately 40 million people are suffering from dementia, globally. Dementia is a group of symptoms that affect neurons and cause some mental disorders, such as losing memory. Alzheimer's disease (AD) which is known as the most common cause of dementia, is one of the top medical care concerns across the world. Although the exact sources of the disease are not understood, is it believed that aggregation of amyloid-beta (Aß) outside of neuron cells and tau aggregation or neurofibrillary tangles (NFTs) formation inside the cell may play crucial roles. In this paper, we are going to review studies that targeted inhibition of amyloid plaque and tau protein tangle formation, to suppress or postpone AD.

Identification of an aspidospermine derivative from borage extract as an anti-amyloid compound: A possible link between protein aggregation and antimalarial drugs.

A number of human diseases, including Alzheimer's and Parkinson's have been linked to amyloid formation. To search for an anti-amyloidogenic product, alkaloid enriched extract from borage leaves was examined for anti-amyloidogenic activity using Hen Egg White Lysozyme (HEWL) as a model protein. After isolation of the plant extract using rHPLC, only one fraction indicated a significant bioactivity. TEM analysis confirmed a remarkable reduction of amyloid fibrils in the presence of the bioactive fraction. To identify the effective substance in the fraction, mass spectrometry, FTIR, and NMR were performed. Our analyses determined that the bioactive compound as 1-acetyl-19,21-epoxy-15,16-dimethoxyaspidospermidine-17-ol, a derivative of aspidospermine. To investigate the mechanism of the inhibition, ANS binding, intrinsic fluorescence, and amide I content were performed in the presence of the bioactive compound. All the results confirmed the role of the compound in assisting the proper folding of the protein. In addition, molecular docking indicated the aspidospermine derivative binds the amyloidogenic region of the protein. Our results show that the alkaloid extracted from borage leaves reduces protein aggregation mediating through structural elements of the protein, promoting the correct folding of lysozyme. Since a number of aspidospermine compounds have been shown to possess potent antimalarial activities, the action of compound identified in the present study suggests a possible link between protein aggregation and aspidospermine drugs.

Detection of copy number changes in genes associated with Parkinson's disease in Iranian patients.

Parkinson's disease (PD) is the second most common neurodegenerative disorder, after Alzheimer's disease. Genomic rearrangements are common mutations reported in PD patients. In this study, we investigated the prevalence of genomic rearrangements in a total of 232 Iranian PD patients, out of which 102 were sporadic early-onset (age-at-onset ≤ 45 years) and 51 had a family history. We used multiplex ligation-dependent probe amplification (MLPA) method to detect exon dosage changes. Two new improved probe kits, SALSA P051 and P052, were used and altogether α-synuclein, parkin, UCHL1, PINK1, DJ-1, LRRK2, GCH1, ATP13A2, CAV1, CAV2, LPA and TNFRSF9 genes were analyzed. Exon or whole-gene rearrangements were identified in 14 (13.7%) sporadic early-onset PD patients in parkin, α-synuclein and PINK1. Of familial PD patients 46 cases from 18 families (35.3%) showed exon or whole-gene rearrangements in parkin, α-synuclein, PINK1, DJ-1, and ATP13A2 genes. All changes were verified by quantitative PCR (qPCR). Novel mutations and unusual clinical features are reported in this study. Mutations in parkin were the predominant genetic cause in both early-onset and familial PD groups. Also the mutations observed in family PD group are more in number and diversity than the sporadic early-onset PD group.

Biased homozygous haplotypes across the human caveolin 1 upstream purine complex in Parkinson's disease.

The alpha-synuclein-caveolin 1 axis is suggested to be of role in the pathogenesis of Parkinson's disease in cell line models. The objective of this study was to analyze the homozygous haplotype compartment of the human caveolin 1 gene upstream purine complex in patients afflicted with Parkinson's disease. This complex was screened in patients with Parkinson's disease (n = 141) and compared with a group of controls (n = 760) using polymerase chain reaction and sequencing. The expression activity of the homozygous haplotypes was then examined using luciferase Dual-Glo system in human neuronal cell line, LAN-5. Six haplotypes were found to be homozygous in the patients, and not in the control pool (Fisher exact p < 1 × 10(-6)). Three of those haplotypes were specific to Parkinson's disease (Fisher exact p < 0.002), and the remaining three overlapped with homozygous haplotypes in Alzheimer's disease and multiple sclerosis (Fisher exact p < 0.002). The disease haplotypes contained motif lengths that were nonexistent in the control homozygous haplotype pool and significantly increased gene expression (p < 9 × 10(-6)). We conclude that skew in the caveolin 1 purine complex homozygous haplotype compartment and an additive effect of those haplotypes may be linked with Parkinson's disease.

Corpus callosotomy with gamma knife radiosurgery for a case of intractable generalised epilepsy.

Gamma knife radiosurgery is a minimally invasive procedure which can be used for patients with intractable epilepsies as an alternative for surgical corpus callosotomy. We report a 13-year-old boy with intractable epilepsy who underwent radiosurgical callosotomy. The patient demonstrated significant clinical improvement after gamma knife radiosurgery and was free of seizures 10 months after the procedure. However, He developed four short focal seizures with clonic movements during the 20 months post radiosurgery. Corpus callosotomy decreased epileptiform discharges in both hemispheres, indicating a role for the callosal neurons to facilitate an asymmetric epileptogenic susceptible state within the two hemispheres such that bisynchronous and bisymmetrical epileptiform discharges develop. Our result demonstrates that this novel therapeutic approach is a safe and effective option for the treatment of intractable generalised epilepsies.

Open-label trial of cinnarizine in migraine prophylaxis.

OBJECTIVE: To assess the effectiveness and safety of cinnarizine as a migraine-preventive therapy. METHODS: Sixty patients with more than 2 migraine headache attacks during a 4-week baseline entered the study and received a 25-mg tablet cinnarizine twice daily for the first 3 days and then 3 times daily. They were assessed on weeks 2, 6, 10, and 14. Reduction from baseline in 4-week migraine headache rate was the primary efficacy variable. Reduction in migraine attacks duration and severity was also evaluated. RESULTS: The mean reduction in 4-week migraine headache rate was 4.6 +/- 2.2 from the baseline of 6.2 +/- 2.2 after 14 weeks of treatment, which was statistically significant (P < 0.001). Percent reduction in 4-week migraine frequency was 35% after 2 weeks, 74% after 6 weeks, 74% after 10 weeks, and 75% after 14 weeks of treatment. Significant reduction in attack duration (P < 0.001) and severity (P < 0.001) was also noted. No serious adverse events were observed in this series of patient. CONCLUSION: Cinnarizine is an efficacious and well-tolerated prophylactic antimigraine medication, which has early onset effectiveness.