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28 result(s) for "SCA2 protein"
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Road properties of cement-phosphogypsum-red clay under dry and wet cycles
In this paper, the road performance and mechanism of cement-phosphogypsum-red clay (CPRC) under dry and wet cycling were systematically investigated using 5% cement as curing agent, the mass ratio of phosphogypsum: red clay = 1:1, and 5% SCA-2 as water stabilizer. The road performance of dry and wet cycle mix was verified with the National Highway G210 Duyun Yangan to Yingshan Highway Reconstruction and Expansion Project as a test road to provide a scientific basis for the application of cement-phosphogypsum-red clay on roads. The results show that the cement-phosphogypsum-red clay unconfined compressive strength decreases with the increase of the number of wet and dry cycles, with a larger decay in the first three times and leveling off thereafter. The CBR value meets the requirements of roadbed fill on highway and Class I roads as stipulated in the Design Code for Highway Roadbeds (JTG D30-2015). SCA-2 water stabilizer reduces the strength of the mixture, but significantly improve the water stability performance of the mixture, the reason SCA-2 water stabilizer active ingredients and mixing particles of physicochemical reaction, the content of ettringite in the mixture is lower than the content of the mixture not mixed with water stabilizers, the generation of quartz, white mica, and kaolinite and other hydrophilic poor material increases, the surface of the cementitious material increases, the seepage channel is reduced, so the strength is reduced, and water stability performance is improved. The roadbed of the test road was smooth and dense, with no scouring, peeling or cracking. The settlement of the roadbed is less than the requirement of “Highway Roadbed Design Specification” (JTGD30-2015). Cement-phosphogypsum-red clay (cement 5%, phosphogypsum 47.5%, red clay 47.5%, SCA-2 water stabilizer 5%) can be used as filler for road bed on highway and primary road base.
EMG Rectification Is Detrimental for Identifying Abnormalities in Corticomuscular and Intermuscular Coherence in Spinocerebellar Ataxia Type 2
Corticomuscular and intermuscular coherence (CMC, IMC) reflect connectivity between neuronal activity in the motor cortex measured by electroencephalography (EEG) and muscular activity measured by electromyography (EMG), or between activity in different muscles, respectively. There is an ongoing debate on the appropriateness of EMG rectification prior to coherence estimation. This work examines the effects of EMG rectification in CMC and IMC estimation in 20 spinocerebellar ataxia type 2 (SCA2) patients, 16 prodromal SCA2 gene mutation carriers, and 26 healthy controls during a repetitive upper or lower limb motor task. Coherence estimations were performed using the non-rectified raw EMG signal vs. the rectified EMG signal. EMG rectification decreases the level of significance of lower beta-frequency band CMC and IMC values in SCA2 patients and prodromal SCA2 mutation carriers vs. healthy controls, and also results in overall lower coherence values. EMG rectification is detrimental for beta-frequency band CMC and IMC estimation. One likely reason for this effect is distortion of coherence estimation in high-frequency signals, where the level of amplitude cancelation is high.
Overwhelming genetic heterogeneity and exhausting molecular diagnostic process in chronic and progressive ataxias: facing it up with an algorithm, a gene, a panel at a time
Ataxias are one of the most frequent complaints in Neurogenetics units worldwide. Currently, more than 50 subtypes of spinocerebellar ataxias and more than 60 recessive ataxias are recognized. We conducted an 11-year prospective, observational, analytical study in order to estimate the frequency of pediatric and adult genetic ataxias in Argentina, to describe the phenotypes of this cohort and evaluate the diagnostic yield of the algorithm used in our unit. We included 334 ataxic patients. Our diagnostic approach was successful in one-third of the cohort. A final molecular diagnosis was reached in 113 subjects. This rate is significantly higher in the subgroup of patients with a positive family history, where the diagnostic yield increased to 55%. The most prevalent dominant and recessive ataxias in Argentina were SCA-2 (36% of dominant ataxias) and FA (62% of recessive ataxias), respectively. Next generation sequencing-based assays were diagnostic in the 65% of the patients requiring these tests. These results provide relevant epidemiological information, bringing a comprehensive knowledge of the most prevalent subtypes of genetic ataxias and their phenotypes in our territory and laying the groundwork for rationally implementing genetic diagnostic programs for these disorders in our country.
Efficient hydroxylation of flavonoids by using whole-cell P450 sca-2 biocatalyst in Escherichia coli
The hydroxylation is an important way to generate the functionalized derivatives of flavonoids. However, the efficient hydroxylation of flavonoids by bacterial P450 enzymes is rarely reported. Here, a bacterial P450 sca-2 mut whole-cell biocatalyst with an outstanding 3′-hydroxylation activity for the efficient hydroxylation of a variety of flavonoids was first reported. The whole-cell activity of sca-2 mut was enhanced using a novel combination of flavodoxin Fld and flavodoxin reductase Fpr from Escherichia coli. In addition, the double mutant of sca-2 mut (R88A/S96A) exhibited an improved hydroxylation performance for flavonoids through the enzymatic engineering. Moreover, the whole-cell activity of sca-2 mut (R88A/S96A) was further enhanced by the optimization of whole-cell biocatalytic conditions. Finally, eriodictyol, dihydroquercetin, luteolin, and 7,3′,4′-trihydroxyisoflavone, as examples of flavanone, flavanonol, flavone, and isoflavone, were produced by whole-cell biocatalysis using naringenin, dihydrokaempferol, apigenin, and daidzein as the substrates, with the conversion yield of 77%, 66%, 32%, and 75%, respectively. The strategy used in this study provided an effective method for the further hydroxylation of other high value-added compounds.
Mechanistic Insights into the Binding of Class IIa HDAC Inhibitors toward Spinocerebellar Ataxia Type-2: A 3D-QSAR and Pharmacophore Modeling Approach
Spinocerebellar ataxia (SCA-2) type-2 is a rare neurological disorder among the nine polyglutamine disorders, mainly caused by polyQ (CAG) trinucleotide repeats expansion within gene coding ataxin-2 protein. The expanded trinucleotide repeats within the ataxin-2 protein sequesters transcriptional cofactors i.e., CREB-binding protein (CBP), Ataxin-2 binding protein 1 (A2BP1) leading to a state of hypo-acetylation and transcriptional repression. Histone de-acetylases inhibitors (HDACi) have been reported to restore transcriptional balance through inhibition of class IIa HDAC's, that leads to an increased acetylation and transcription as demonstrated through studies on mouse models of Huntington's. In this study, 61 di-aryl cyclo-propanehydroxamic acid derivatives were used for developing three dimensional (3D) QSAR and pharmacophore models. These models were then employed for screening and selection of anti-ataxia compounds. The chosen QSAR model was observed to be statistically robust with correlation coefficient ( ) value of 0.6774, cross-validated correlation coefficient ( ) of 0.6157 and co-relation coefficient for external test set ( _ ) of 0.7570. A high -test value of 77.7093 signified the robustness of the model. Two potential drug leads ZINC 00608101 (SEI) and ZINC 00329110 (ACI) were selected after a coalesce procedure of pharmacophore based screening using the pharmacophore model ADDRR.20 and structural analysis using molecular docking and dynamics simulations. The pharmacophore and the 3D-QSAR model generated were further validated for their screening and prediction ability using the enrichment factor (EF), goodness of hit (GH), and receiver operating characteristics (ROC) curve analysis. The compounds SEI and ACI exhibited a docking score of -10.097 and -9.182 kcal/mol, respectively. An evaluation of binding conformation of ligand-bound protein complexes was performed with MD simulations for a time period of 30 ns along with free energy binding calculations using the g_mmpbsa technique. Prediction of inhibitory activities of the two lead compounds SEI (7.53) and ACI (6.84) using the 3D-QSAR model reaffirmed their inhibitory characteristics as potential anti-ataxia compounds.
Analysis of gene expression profiles in human systemic lupus erythematosus using oligonucleotide microarray
Epidemiologic studies suggest a strong genetic component for susceptibility to systemic lupus erythematosus (SLE). To investigate the genetic mechanism of pathogenesis of SLE, we studied the difference in gene expression of peripheral blood cells between 10 SLE patients and 18 healthy controls using oligonucleotide microarray. When gene expression for patients was compared to the mean of normal controls, among the 3002 target genes, 61 genes were identified with greater than a two-fold change difference in expression level. Of these genes, 24 were upregulated and 37 downregulated in at least half of the patients. By the Welch's ANOVA/Welch's t -test, all these 61 genes were significantly different ( P <0.05) between SLE patients and normal controls. Among these genes with differential expression, IFN-ω and Ly6E (TSA-1/Sca-2) may play an important role in the mechanism of SLE pathogenesis. TSA-1 antigens may represent an important alternative pathway for T-cell activation that may be involved in IFN-mediated immunomodulation. Hierarchical clustering showed that patient samples were clearly separated from controls based on their gene expression profile. These results demonstrate that high-density oligonucleotide microarray has the potential to explore the mechanism of pathogenesis of systemic lupus erythematosus.
The pathogenesis of spinocerebellar ataxia
Six forms of spinocerebellar ataxia (SCA) are caused by pathological cytosine-adenine-guanine (CAG) trinucleotide repeat expansions in the coding region of the mutated genes. The translated proteins contain abnormally long polyglutamine stretches, and SCA-1, SCA-2, SCA-3/Machado-Joseph disease (MJD), SCA-6, SCA-7, and SCA-17 are \"polyglutamine diseases\". Despite their clinical and genetic heterogeneity, the ataxia-causing lesions in the brain invariably affect the \"cerebellar module\" that is defined as a reciprocal circuitry between the cerebellar cortex, the dentate nuclei, and the inferior olivary nuclei. While the neurons of the basis pontis do not properly belong to this module, pontine atrophy is an important additional lesion in SCA-1, SCA-2, and SCA-7. The descriptive term olivopontocerebellar atrophy (OPCA) applies to these forms whereas SCA-6 is the prototype of \"pure\" cerebellar cortical or cerebello-olivary atrophy. Purkinje cells have an elaborate dendritic tree, and atrophy of these most remarkable cells has captured the attention of many morphologists. Almost invariably, the loss of Purkinje cells entails retrograde neuronal degeneration in the inferior olivary nuclei. However, SCA-6 is an exception, and many olivary neurons survive. Similarly, stellate, basket, and granule cells do not undergo commensurate retrograde atrophy when Purkinje cells disappear. The dentate nucleus displays \"grumose\" degeneration in SCA-3/MJD while the cerebellar cortex and the inferior olivary nuclei remain largely unaffected. The role of polyglutamine-containing intranuclear and cytoplasmic inclusion bodies in SCA remains unknown but protein aggregation may be the common step in the pathogenesis of these otherwise rather heterogeneous disorders.
Ataxin-2 Disordered Region Promote Huntingtin Protein Aggregation And Neurodegeneration In Drosophila Models Of Huntington's Disease
The Ataxin-2 (Atx2) protein contributes to the progression of neurodegenerative phenotypes in animal models of amyotrophic lateral sclerosis (ALS), type 2 spinocerebellar ataxia (SCA-2), Parkinsons Disease (PD) and Huntingtons Disease (HD). However, because the Atx2 protein contains multiple separable activities, deeper understanding requires experiments to address the exact mechanisms by which Atx2 modulates ND progression. Recent work on two ALS models, C9ORF72 and FUS, in Drosophila has shown that a C-terminal intrinsically disordered region (cIDR) of Atx2 protein, required for assembly of RNP granules, is essential for the progression of neurodegenerative phenotypes as well as for accumulation of protein inclusions associated with these ALS models. Here we show that the Atx2-cIDR also similarly contributes to the progression of degenerative phenotypes and accumulation of Huntingtin protein aggregates in Drosophila models of HD. Because Huntingtin is not an established component of RNP granules, these observations support a recently hypothesised, unexpected protein-handling function for RNP granules, which could contribute to the progression of Huntingtons disease and, potentially, other proteinopathies.
Characterization of changes in gene expression associated with malignant transformation by the NF-κB family member, v-Rel
In this study, alterations in gene expression patterns have been examined in v-Rel-transformed avian bone marrow cells. Using a conditional v-Rel estrogen receptor chimera (v-RelER) which transforms cells in an estrogen-dependent manner, we constructed subtraction cDNA libraries from v-RelER-transformed bone marrow cells. Several different sequences were identified whose expression was altered upon hormone activation of v-RelER. These include two genes related to the MIP-1 chemokine family (mip-1β and a tca3 homologue), a cell surface antigen sca-2 and the transcription factor nfkb1. The expression of each gene was assayed in a number of wild-type and mutant v-Rel-expressing fibroblast and hematopoietic cells. All v-Rel-transformed hematopoietic cells tested express high levels of nfkb1 and sca-2. In fibroblasts, wild-type v-Rel induced expression of mip-1β and nfkb1, while nontransforming mutants of v-Rel failed to do so, suggesting a role for these two genes in v-Rel mediated transformation. Finally, these genes are expressed at high levels in cells overexpressing wild-type and truncated forms of c-Rel, implying that v-Rel transforms, in part, by induction of c-Rel target genes.
Mid-Gestation lethality of Atxn2l-Ablated Mice
Depletion of yeast/fly Ataxin-2 rescues TDP-43 overexpression toxicity. In mouse models of Amyotrophic Lateral Sclerosis via TDP-43 overexpression, depletion of its ortholog ATXN2 mitigated motor neuron degeneration and extended lifespan from 25 days to >300 days. There is another ortholog in mammals, named ATXN2L (Ataxin-2-like), which is almost uncharacterized but also functions in RNA surveillance at stress granules. We generated mice with Crispr/Cas9-mediated deletion of Atxn2l exons 5-8, studying homozygotes prenatally and heterozygotes during aging. Our novel findings indicate that ATXN2L absence triggers mid-gestational embryonic lethality, affecting female animals more strongly. Weight and development stages of homozygous mutants were reduced. Placenta phenotypes were not apparent, but brain histology showed lamination defects and apoptosis. Aged heterozygotes showed no locomotor deficits or weight loss over 12 months. Null mutants in vivo displayed compensatory efforts to maximize Atxn2l expression, which were prevented upon nutrient abundance in vitro. Mouse embryonal fibroblast cells revealed more multinucleated giant cells upon ATXN2L deficiency. In addition, in human neural cells, transcript levels of ATXN2L were induced upon starvation and glucose and amino acids exposure, but this induction was partially prevented by serum or low cholesterol administration. Neither ATXN2L depletion triggered dysregulation of ATXN2, nor a converse effect was observed. Overall, this essential role of ATXN2L for embryogenesis raises questions about its role in neurodegenerative diseases and neuroprotective therapies.