Během posledních tří desetiletí byl zaznamenán významný pokrok v chápání molekulární etiologie dědičných neurodegenerativních demencí. Byly objeveny geny pro dědičné neurodegenerativní nemoci a množství studií pro vývoj terapií modifikujících onemocnění narůstá. Většina neurodegenerativních demencí se klinicky liší, ač mají společný patofyziologický dopad. U neurodegenerací dochází k zániku neuronů apoptotickou signální dráhou na podkladě ukládání depozit patologicky změněného proteinu v mozkové tkáni, tzv. proteinopatie. U genetických (dědičných) neurodegenerací hrají zásadní roli v patofyziologických mechanizmech konformační změny proteinů, genové aberace či polymorfizmy. Klinické projevy a neuropatologické nálezy dědičných forem neurodegenerativních demencí jsou často nerozlišitelné od sporadických typů, což zvyšuje potřebu molekulárně genetické analýzy genů zodpovědných za různé neurodegenerace. Účelem sdělení je provést stručný přehled genů, které jsou důležité v patofyziologii neurodegenerativních demencí v rutinní diagnostické praxi a možnosti jejich vyšetření.
Over the past three decades, significant advances have been made in understanding the molecular etiology of hereditary neurodegenerative dementias. Specific genes responsible for hereditary neurodegenerative diseases have been discovered, and studies on the development of disease-modifying therapies have been accelerated. Most neurodegenerative dementias are clinically different, although they share a common pathophysiological background. In neurodegeneration, neuronal atrophy due to apoptotic signalling pathway influenced by deposition of pathologically altered protein in the brain tissue are the leading mechanisms, thus, these diseases are called proteinopathies. In genetic (hereditary) neurodegenerations, conformational changes of proteins, gene aberrations or polymorphisms play crucial roles in pathophysiological mechanisms. Clinical manifestations and neuropathological findings of hereditary forms of neurodegenerative dementia are often inseparable from sporadic types, which increases an urgent need for molecular-genetic analysis of genes responsible for various neurodegenerations. The purpose of this work is to provide a brief overview of the most important genes related to the pathophysiology of neurodegenerative dementias in routine diagnostic practice and the possibilities of their detection.
BACKGROUND: Posterior fossa ependymoma (PFE) comprises 2 groups, PF group A (PFA) and PF group B (PFB), with stark differences in outcome. However, to the authors' knowledge, the long-term outcomes of PFA ependymoma have not been described fully. The objective of the current study was to identify predictors of survival and neurocognitive outcome in a large consecutive cohort of subgrouped patients with PFE over 30 years. METHODS: Demographic, survival, and neurocognitive data were collected from consecutive patients diagnosed with PFE from 1985 through 2014 at the Hospital for Sick Children in Toronto, Ontario, Canada. Subgroup was assigned using genome-wide methylation array and/or immunoreactivity to histone H3 K27 trimethylation (H3K27me3). RESULTS: A total of 72 PFE cases were identified, 89% of which were PFA. There were no disease recurrences noted among patients with PFB. The 10-year progression-free survival rate for all patients with PFA was poor at 37.1% (95% confidence interval, 25.9%-53.1%). Analysis of consecutive 10-year epochs revealed significant improvements in progression-free survival and/or overall survival over time. This pertains to the increase in the rate of gross (macroscopic) total resection from 35% to 77% and the use of upfront radiotherapy increasing from 65% to 96% over the observed period and confirmed in a multivariable model. Using a mixed linear model, analysis of longitudinal neuropsychological outcomes restricted to patients with PFA who were treated with focal irradiation demonstrated significant continuous declines in the full-scale intelligence quotient over time with upfront conformal radiotherapy, even when correcting for hydrocephalus, number of surgeries, and age at diagnosis (-1.33 ± 0.42 points/year; P = .0042). CONCLUSIONS: Data from a molecularly informed large cohort of patients with PFE clearly indicate improved survival over time, related to more aggressive surgery and upfront radiotherapy. However, to the best of the authors' knowledge, the current study is the first, in a subgrouped cohort, to demonstrate that this approach results in reduced neurocognitive outcomes over time.
- MeSH
- Survival Analysis MeSH
- Child MeSH
- Ependymoma mortality psychology therapy MeSH
- Infratentorial Neoplasms mortality psychology therapy MeSH
- Infant MeSH
- Humans MeSH
- Adolescent MeSH
- Neoadjuvant Therapy adverse effects MeSH
- Neurosurgical Procedures adverse effects MeSH
- Neurocognitive Disorders etiology MeSH
- Child, Preschool MeSH
- Radiotherapy adverse effects MeSH
- Treatment Outcome MeSH
- Check Tag
- Child MeSH
- Infant MeSH
- Humans MeSH
- Adolescent MeSH
- Male MeSH
- Child, Preschool MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Research Support, N.I.H., Extramural MeSH
- Geographicals
- Ontario MeSH
BACKGROUND: The Synurophyceae is one of most important photosynthetic stramenopile algal lineages in freshwater ecosystems. They are characterized by siliceous scales covering the cell or colony surface and possess plastids of red-algal secondary or tertiary endosymbiotic origin. Despite their ecological and evolutionary significance, the relationships amongst extant Synurophyceae are unclear, as is their relationship to most other stramenopiles. RESULTS: Here we report a comparative analysis of plastid genomes sequenced from five representative synurophycean algae. Most of these plastid genomes are highly conserved with respect to genome structure and coding capacity, with the exception of gene re-arrangements and partial duplications at the boundary of the inverted repeat and single-copy regions. Several lineage-specific gene loss/gain events and intron insertions were detected (e.g., cemA, dnaB, syfB, and trnL). CONCLUSIONS: Unexpectedly, the cemA gene of Synurophyceae shows a strong relationship with sequences from members of the green-algal lineage, suggesting the occurrence of a lateral gene transfer event. Using a molecular clock approach based on silica fossil record data, we infer the timing of genome re-arrangement and gene gain/loss events in the plastid genomes of Synurophyceae.
- MeSH
- Phylogeny MeSH
- Genetic Variation * MeSH
- Genome, Plastid * MeSH
- Genomics * MeSH
- Gene Dosage MeSH
- Stramenopiles genetics MeSH
- Nucleic Acid Conformation MeSH
- DNA, Circular genetics MeSH
- Evolution, Molecular MeSH
- Inverted Repeat Sequences genetics MeSH
- RNA, Transfer chemistry genetics MeSH
- Base Sequence MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Comparative Study MeSH
The minor phospholipid, phosphatidylinositol 4-phosphate (PI4P), is emerging as a key regulator of lipid transfer in ER-membrane contact sites. Four different phosphatidylinositol 4-kinase (PI4K) enzymes generate PI4P in different membrane compartments supporting distinct cellular processes, many of which are crucial for the maintenance of cellular integrity but also hijacked by intracellular pathogens. While type III PI4Ks have been targeted by small molecular inhibitors, thus helping decipher their importance in cellular physiology, no inhibitors are available for the type II PI4Ks, which hinders investigations into their cellular functions. Here, we describe the identification of small molecular inhibitors of PI4K type II alpha (PI4K2A) by implementing a large scale small molecule high-throughput screening. A novel assay was developed that allows testing of selected inhibitors against PI4K2A in intact cells using a bioluminescence resonance energy transfer approach adapted to plate readers. The compounds disclosed here will pave the way to the optimization of PI4K2A inhibitors that can be used in cellular and animal studies to better understand the role of this enzyme in both normal and pathological states.
- MeSH
- 1-Phosphatidylinositol 4-Kinase antagonists & inhibitors chemistry metabolism MeSH
- Biological Transport MeSH
- Chlorocebus aethiops MeSH
- COS Cells MeSH
- Endosomes drug effects metabolism MeSH
- Golgi Apparatus drug effects metabolism MeSH
- HEK293 Cells MeSH
- Enzyme Inhibitors metabolism pharmacology MeSH
- Protein Conformation MeSH
- Humans MeSH
- Drug Evaluation, Preclinical MeSH
- High-Throughput Screening Assays * MeSH
- Molecular Docking Simulation MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Research Support, N.I.H., Intramural MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
The transient receptor potential channel of melastatin 4 (TRPM4) belongs to a group of large ion receptors that are involved in countless cell signalling cascades. This unique member is ubiquitously expressed in many human tissues, especially in cardiomyocytes, where it plays an important role in cardiovascular processes. Transient receptor potential channels (TRPs) are usually constituted by intracellular N- and C- termini, which serve as mediators affecting allosteric modulation of channels, resulting in the regulation of the channel function. The TRPs tails contain a number of conserved epitopes that specifically bind the intracellular modulators. Here, we identify new binding sites for the calmodulin (CaM) and S100 calcium-binding protein A1 (S100A1), located in the very distal part of the TRPM4 N terminus. We have used chemically synthesized peptides of the TRPM4, mimicking the binding epitopes, along with fluorescence methods to determine and specify CaM- and S100A1-binding sites. We have found that the ligands binding epitopes at the TRPM4 N terminus overlap, but the interacting mechanism of both complexes is probably different. The molecular models supported by data from the fluorescence method confirmed that the complexes formations are mediated by the positively charged (R139, R140, R144) and hydrophobic (L134, L138, V143) residues present at the TRPM4 N terminus-binding epitopes. The data suggest that the molecular complexes of TRPM4/CaM and TRPM4/S100A1 would lead to the modulation of the channel functions.
- MeSH
- Databases, Protein MeSH
- Epitopes MeSH
- Expert Systems MeSH
- Fluorescence Polarization MeSH
- Protein Interaction Domains and Motifs MeSH
- Calmodulin chemistry genetics metabolism MeSH
- TRPM Cation Channels chemistry genetics metabolism MeSH
- Kinetics MeSH
- Protein Conformation MeSH
- Conserved Sequence MeSH
- Humans MeSH
- Ligands MeSH
- Models, Molecular * MeSH
- Mutation MeSH
- Peptide Fragments chemical synthesis chemistry genetics metabolism MeSH
- S100 Proteins chemistry genetics metabolism MeSH
- Recombinant Proteins chemistry metabolism MeSH
- Amino Acid Sequence MeSH
- Molecular Docking Simulation MeSH
- Amino Acid Substitution MeSH
- Binding Sites MeSH
- Computational Biology MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Comparative Study MeSH
Alzheimer's disease (AD) is one of the most significant neurodegenerative disorders and its symptoms mostly appear in aged people. Catechol-o-methyltransferase (COMT) is one of the known target enzymes responsible for AD. With the use of 23 known inhibitors of COMT, a query has been generated and validated by screening against the database of 1500 decoys to obtain the GH score and enrichment value. The crucial features of the known inhibitors were evaluated by the online ZINC Pharmer to identify new leads from a ZINC database. Five hundred hits were retrieved from ZINC Pharmer and by ADMET (absorption, distribution, metabolism, excretion, and toxicity) filtering by using FAF-Drug-3 and 36 molecules were considered for molecular docking. From the COMT inhibitors, opicapone, fenoldopam, and quercetin were selected, while ZINC63625100_413 ZINC39411941_412, ZINC63234426_254, ZINC63637968_451, and ZINC64019452_303 were chosen for the molecular dynamics simulation analysis having high binding affinity and structural recognition. This study identified the potential COMT inhibitors through pharmacophore-based inhibitor screening leading to a more complete understanding of molecular-level interactions.
- MeSH
- Alzheimer Disease drug therapy enzymology physiopathology MeSH
- Gene Expression MeSH
- Databases, Pharmaceutical MeSH
- Catechol O-Methyltransferase Inhibitors chemistry pharmacology MeSH
- Protein Interaction Domains and Motifs MeSH
- Catechol O-Methyltransferase chemistry MeSH
- Kinetics MeSH
- Protein Conformation, alpha-Helical MeSH
- Protein Conformation, beta-Strand MeSH
- Humans MeSH
- Ligands MeSH
- Nootropic Agents chemistry pharmacology MeSH
- High-Throughput Screening Assays * MeSH
- Molecular Dynamics Simulation MeSH
- Molecular Docking Simulation MeSH
- Substrate Specificity MeSH
- Protein Structure, Tertiary MeSH
- Thermodynamics MeSH
- Protein Binding MeSH
- Binding Sites MeSH
- Structure-Activity Relationship MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
Cyanobacteria possess a family of one-helix high-light-inducible proteins (HLIPs) that are widely viewed as ancestors of the light-harvesting antenna of plants and algae. HLIPs are essential for viability under various stress conditions, although their exact role is not fully understood. The unicellular cyanobacterium Synechocystis sp. PCC 6803 contains four HLIPs named HliA-D, and HliD has recently been isolated in a small protein complex and shown to bind chlorophyll and β-carotene. However, no HLIP has been isolated and characterized in a pure form up to now. We have developed a protocol to purify large quantities of His-tagged HliC from an engineered Synechocystis strain. Purified His-HliC is a pigmented homo-oligomer and is associated with chlorophyll and β-carotene with a 2:1 ratio. This differs from the 3:1 ratio reported for HliD. Comparison of these two HLIPs by resonance Raman spectroscopy revealed a similar conformation for their bound β-carotenes, but clear differences in their chlorophylls. We present and discuss a structural model of HliC, in which a dimeric protein binds four chlorophyll molecules and two β-carotenes.
- MeSH
- Bacterial Proteins chemistry genetics isolation & purification metabolism MeSH
- beta Carotene metabolism MeSH
- Chlorophyll metabolism MeSH
- Protein Multimerization MeSH
- Spectrum Analysis, Raman MeSH
- Recombinant Proteins genetics isolation & purification metabolism MeSH
- Light-Harvesting Protein Complexes genetics metabolism MeSH
- Synechocystis genetics metabolism physiology MeSH
- Publication type
- Journal Article MeSH
Mutations that alter signaling of RAS/MAPK-family proteins give rise to a group of Mendelian diseases known as RASopathies. However, among RASopathies, the matrix of genotype-phenotype relationships is still incomplete, in part because there are many RAS-related proteins and in part because the phenotypic consequences may be variable and/or pleiotropic. Here, we describe a cohort of ten cases, drawn from six clinical sites and over 16,000 sequenced probands, with de novo protein-altering variation in RALA, a RAS-like small GTPase. All probands present with speech and motor delays, and most have intellectual disability, low weight, short stature, and facial dysmorphism. The observed rate of de novo RALA variants in affected probands is significantly higher (p = 4.93 x 10(-11)) than expected from the estimated random mutation rate. Further, all de novo variants described here affect residues within the GTP/GDP-binding region of RALA; in fact, six alleles arose at only two codons, Val25 and Lys128. The affected residues are highly conserved across both RAL- and RAS-family genes, are devoid of variation in large human population datasets, and several are homologous to positions at which disease-associated variants have been observed in other GTPase genes. We directly assayed GTP hydrolysis and RALA effector-protein binding of the observed variants, and found that all but one tested variant significantly reduced both activities compared to wild-type. The one exception, S157A, reduced GTP hydrolysis but significantly increased RALA-effector binding, an observation similar to that seen for oncogenic RAS variants. These results show the power of data sharing for the interpretation and analysis of rare variation, expand the spectrum of molecular causes of developmental disability to include RALA, and provide additional insight into the pathogenesis of human disease caused by mutations in small GTPases.
- MeSH
- Facies MeSH
- Phenotype MeSH
- Genotype MeSH
- Guanosine Diphosphate metabolism MeSH
- Guanosine Triphosphate metabolism MeSH
- Protein Interaction Domains and Motifs genetics MeSH
- Protein Conformation MeSH
- Humans MeSH
- Intellectual Disability genetics MeSH
- Mutation, Missense MeSH
- Mitochondrial Proteins chemistry genetics MeSH
- Models, Molecular MeSH
- Mutation * MeSH
- ral GTP-Binding Proteins chemistry genetics MeSH
- ras Proteins chemistry genetics MeSH
- Developmental Disabilities genetics MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Research Support, N.I.H., Extramural MeSH
Components of ginger (Zingiber officinale) extracts have been described as potential new drug candidates against Alzheimer disease (AD), able to interact with several molecular targets related to the AD treatment. However, there are very few theoretical studies in the literature on the possible mechanisms of action by which these compounds can work as potential anti-AD drugs. For this reason, we performed here docking, molecular dynamic simulations and mmpbsa calculations on four components of ginger extracts former reported as active inhibitors of human acetylcholinesterase (HssAChE), and compared our results to the known HssAChE inhibitor and commercial drug in use against AD, donepezil (DNP). Our findings points to two among the compounds studied: (E)-1,7-bis(4-hydroxy-3-methoxyphenyl)hept-4-en-3-on and 1-(3,4-dihydroxy-5-methoxyphenyl)-7-(4-hydroxy-3- ethoxyphenyl) heptane-3,5-diyl diacetate, as promising new HssAChE inhibitors that could be as effective as DNP. We also mapped the binding of the studied compounds in the different binding pockets inside HssAChE and established the preferred interactions to be favored in the design of new and more efficient inhibitors.
- MeSH
- Acetylcholinesterase chemistry MeSH
- Algorithms MeSH
- Alzheimer Disease MeSH
- Kinetics MeSH
- Humans MeSH
- Molecular Conformation MeSH
- Molecular Structure MeSH
- Plant Extracts chemistry MeSH
- Molecular Dynamics Simulation * MeSH
- Molecular Docking Simulation MeSH
- Protein Binding MeSH
- Binding Sites MeSH
- Water chemistry MeSH
- Hydrogen Bonding MeSH
- Structure-Activity Relationship MeSH
- Zingiber officinale chemistry MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
Six chlorinated bispyridinium mono-oximes, analogous to potent charged reactivators K027, K048, and K203, were synthesized with the aim of improving lipophilicity and reducing the p Ka value of the oxime group, thus resulting in a higher oximate concentration at pH 7.4 compared to nonchlorinated analogues. The nucleophilicity was examined and the p Ka was found to be lower than that of analogous nonchlorinated oximes. All the new compounds efficiently reactivated human AChE inhibited by nerve agents cyclosarin, sarin, and VX. The most potent was the dichlorinated analogue of oxime K027 with significantly improved ability to reactivate the conjugated enzyme due to improved binding affinity and molecular recognition. Its overall reactivation of sarin-, VX-, and cyclosarin-inhibited AChE was, respectively, 3-, 7-, and 8-fold higher than by K027. Its universality, PAMPA permeability, favorable acid dissociation constant coupled with its negligible cytotoxic effect, and successful ex vivo scavenging of nerve agents in whole human blood warrant further analysis of this compound as an antidote for organophosphorus poisoning.
- MeSH
- Acetylcholinesterase chemistry metabolism MeSH
- Butyrylcholinesterase metabolism MeSH
- Chemical Phenomena MeSH
- Chlorine chemistry MeSH
- Cholinesterase Inhibitors pharmacology MeSH
- Isomerism MeSH
- Protein Conformation MeSH
- Humans MeSH
- Cell Line, Tumor MeSH
- Nerve Agents pharmacology MeSH
- Oximes chemical synthesis chemistry metabolism pharmacology MeSH
- Cholinesterase Reactivators chemical synthesis chemistry metabolism pharmacology MeSH
- Molecular Docking Simulation MeSH
- Structure-Activity Relationship MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
