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1.
Pharmacol Res ; 187: 106583, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36574578

RESUMO

The heterogeneity of tumor immune microenvironment (TIME) plays important roles in the development and immunotherapy response of hepatocellular carcinoma (HCC). Using machine learning algorithms, we introduced the immune index (IMI), a prognostic model based on the HCC immune landscape. We found that IMI low HCCs were enriched in stem cell and proliferating signatures, and yielded more TP53 mutation and 17p loss compared with IMI high HCCs. More importantly, patients with high IMI exhibited better immune-checkpoint blockade (ICB) response. To facilitate clinical application, we employed machine learning algorithms to develop a gene model of the IMI (IMIG), which contained 10 genes. According to our HCC cohort examination and single-cell level analysis, we found that IMIG high HCCs exhibited favorable survival outcomes and high levels of NK and CD8+ T cells infiltration. Finally, after coculture with autologous tumor infiltrating lymphocytes, IMIG high tumor cells exhibited a better response to nivolumab treatment. Collectively, the IMI and IMIG may serve as powerful tools for the prognosis, classification and ICB treatment response prediction of HCC.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/genética , Prognóstico , Linfócitos T CD8-Positivos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/genética , Imunoterapia , Microambiente Tumoral
2.
Molecules ; 28(1)2022 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-36615490

RESUMO

Energy is indispensable in human life and social development, but this has led to an overconsumption of non-renewable energy. Sustainable energy is needed to maintain the global energy balance. Lignocellulose from agriculture or forestry is often discarded or directly incinerated. It is abundantly available to be discovered and studied as a biomass energy source. Therefore, this research uses Staphylea holocarpa wood as feedstock to evaluate its potential as energy source. We characterized Staphylea holocarpa wood by utilizing FT-IR, GC-MS, TGA, Py/GC-MS and NMR. The results showed that Staphylea holocarpa wood contained a large amount of oxygenated volatiles, indicating that it has the ability to act as biomass energy sources which can achieve green chemistry and sustainable development.


Assuntos
Extratos Vegetais , Madeira , Humanos , Espectroscopia de Infravermelho com Transformada de Fourier , Extratos Vegetais/química , Biomassa , Energia Renovável
3.
Proc Natl Acad Sci U S A ; 111(40): 14524-9, 2014 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-25246588

RESUMO

Mutations in the gene encoding ubiquilin2 (UBQLN2) cause amyotrophic lateral sclerosis (ALS), frontotemporal type of dementia, or both. However, the molecular mechanisms are unknown. Here, we show that ALS/dementia-linked UBQLN2(P497H) transgenic mice develop neuronal pathology with ubiquilin2/ubiquitin/p62-positive inclusions in the brain, especially in the hippocampus, recapitulating several key pathological features of dementia observed in human patients with UBQLN2 mutations. A major feature of the ubiquilin2-related pathology in these mice, and reminiscent of human disease, is a dendritic spinopathy with protein aggregation in the dendritic spines and an associated decrease in dendritic spine density and synaptic dysfunction. Finally, we show that the protein inclusions in the dendritic spines are composed of several components of the proteasome machinery, including Ub(G76V)-GFP, a representative ubiquitinated protein substrate that is accumulated in the transgenic mice. Our data, therefore, directly link impaired protein degradation to inclusion formation that is associated with synaptic dysfunction and cognitive deficits. These data imply a convergent molecular pathway involving synaptic protein recycling that may also be involved in other neurodegenerative disorders, with implications for development of widely applicable rational therapeutics.


Assuntos
Esclerose Lateral Amiotrófica/genética , Proteínas de Ciclo Celular/genética , Demência/genética , Mutação , Ubiquitinas/genética , Proteínas Adaptadoras de Transdução de Sinal , Esclerose Lateral Amiotrófica/metabolismo , Esclerose Lateral Amiotrófica/fisiopatologia , Animais , Proteínas Relacionadas à Autofagia , Encéfalo/metabolismo , Encéfalo/patologia , Proteínas de Ciclo Celular/metabolismo , Transtornos Cognitivos/genética , Transtornos Cognitivos/fisiopatologia , Demência/metabolismo , Demência/fisiopatologia , Espinhas Dendríticas/genética , Espinhas Dendríticas/metabolismo , Espinhas Dendríticas/patologia , Espinhas Dendríticas/ultraestrutura , Modelos Animais de Doenças , Hipocampo/metabolismo , Hipocampo/patologia , Humanos , Imuno-Histoquímica , Corpos de Inclusão/metabolismo , Aprendizagem em Labirinto/fisiologia , Camundongos Endogâmicos , Camundongos Transgênicos , Microscopia Confocal , Microscopia Eletrônica , Atividade Motora/genética , Atividade Motora/fisiologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Medula Espinal/metabolismo , Medula Espinal/patologia , Medula Espinal/fisiopatologia , Transmissão Sináptica/genética , Transmissão Sináptica/fisiologia , Ubiquitinas/metabolismo
4.
Cell Discov ; 8(1): 101, 2022 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-36198671

RESUMO

Gallbladder carcinoma (GBC) is the most common biliary tract malignancy with the lowest survival rate, primarily arising from chronic inflammation. To better characterize the progression from inflammation to cancer to metastasis, we performed single-cell RNA sequencing across samples of 6 chronic cholecystitis, 12 treatment-naive GBCs, and 6 matched metastases. Benign epithelial cells from inflamed gallbladders displayed resting, immune-regulating, and gastrointestinal metaplastic phenotypes. A small amount of PLA2G2A+ epithelial cells with copy number variation were identified from a histologically benign sample. We validated significant overexpression of PLA2G2A across in situ GBCs, together with increased proliferation and cancer stemness in PLA2G2A-overexpressing GBC cells, indicating an important role for PLA2G2A during early carcinogenesis. Malignant epithelial cells displayed pervasive cancer hallmarks and cellular plasticity, differentiating into metaplastic, inflammatory, and mesenchymal subtypes with distinct transcriptomic, genomic, and prognostic patterns. Chronic cholecystitis led to an adapted microenvironment characterized by MDSC-like macrophages, CD8+ TRM cells, and CCL2+ immunity-regulating fibroblasts. By contrast, GBC instigated an aggressive and immunosuppressive microenvironment, featured by tumor-associated macrophages, Treg cells, CD8+ TEX cells, and STMN1+ tumor-promoting fibroblasts. Single-cell and bulk RNA-seq profiles consistently showed a more suppressive immune milieu for GBCs with inflammatory epithelial signatures, coupled with strengthened epithelial-immune crosstalk. We further pinpointed a subset of senescence-like fibroblasts (FN1+TGM2+) preferentially enriched in metastatic lesions, which promoted GBC migration and invasion via their secretory phenotype. Collectively, this study provides comprehensive insights into epithelial and microenvironmental reprogramming throughout cholecystitis-propelled carcinogenesis and metastasis, laying a new foundation for the precision therapy of GBC.

5.
Clin Transl Med ; 12(1): e678, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-35075805

RESUMO

BACKGROUND: Gallbladder carcinoma (GBC) is a relatively rare but highly aggressive cancer with late clinical detection and a poor prognosis. However, the lack of models with features consistent with human gallbladder tumours has hindered progress in pathogenic mechanisms and therapies. METHODS: We established organoid lines derived from human GBC as well as normal gallbladder and benign gallbladder adenoma (GBA) tissues. The histopathology signatures of organoid cultures were identified by H&E staining, immunohistochemistry and immunofluorescence. The genetic and transcriptional features of organoids were analysed by whole-exome sequencing and RNA sequencing. A set of compounds targeting the most active signalling pathways in GBCs were screened for their ability to suppress GBC organoids. The antitumour effects of candidate compounds, CUDC-101 and CUDC-907, were evaluated in vitro and in vivo. RESULTS: The established organoids were cultured stably for more than 6 months and closely recapitulated the histopathology, genetic and transcriptional features, and intratumour heterogeneity of the primary tissues at the single-cell level. Notably, expression profiling analysis of the organoids revealed a set of genes that varied across the three subtypes and thus may participate in the malignant progression of gallbladder diseases. More importantly, we found that the dual PI3K/HDAC inhibitor CUDC-907 significantly restrained the growth of various GBC organoids with minimal toxicity to normal gallbladder organoids. CONCLUSIONS: Patient-derived organoids are potentially a useful platform to explore molecular pathogenesis of gallbladder tumours and discover personalized drugs.


Assuntos
Ensaios de Seleção de Medicamentos Antitumorais/métodos , Neoplasias da Vesícula Biliar/diagnóstico , Modelos Biológicos , Organoides/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Ensaios de Seleção de Medicamentos Antitumorais/estatística & dados numéricos , Detecção Precoce de Câncer/instrumentação , Detecção Precoce de Câncer/métodos , Detecção Precoce de Câncer/estatística & dados numéricos , Feminino , Neoplasias da Vesícula Biliar/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Medicina de Precisão/instrumentação , Medicina de Precisão/métodos , Medicina de Precisão/estatística & dados numéricos , Sequenciamento do Exoma/métodos , Sequenciamento do Exoma/estatística & dados numéricos
6.
Clin Transl Med ; 12(11): e1095, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36314067

RESUMO

BACKGROUND: Transketolase (TKT), a key rate-limiting enzyme in the non-oxidative branch of the pentose phosphate pathway (PPP), provides more than 85% of the ribose required for de novo nucleotide biosynthesis and promotes the development of hepatocellular carcinoma (HCC). Pharmacologic inhibition of TKT could impede HCC development and enhance treatment efficacy. However, no safe and effective TKT inhibitor has been approved. METHODS: An online two-dimensional TKT protein immobilised biochromatographic system was established for high-throughput screening of TKT ligands. Oroxylin A was found to specifically bind TKT. Drug affinity responsive target stability, cellular thermal shift assay, surface plasmon resonance, molecular docking, competitive displacement assay, and site mutation were performed to identify the binding of oroxylin A with TKT. Antitumour effects of oroxylin A were evaluated in vitro, in human xenograft mice, diethylnitrosamine (DEN)-induced HCC mice, and patient-derived organoids (PDOs). Metabolomic analysis was applied to detect the enzyme activity. Transcriptome profiling was conducted to illustrate the anti-HCC mechanism of oroxylin A. TKT knocking-down HCC cell lines and PDOs were established to evaluate the role of TKT in oroxylin A-induced HCC suppression. RESULTS: By targeting TKT, oroxylin A stabilised the protein to proteases and temperature extremes, decreased its activity and expression, resulted in accumulation of non-oxidative PPP substrates, and activated p53 signalling. In addition, oroxylin A suppressed cell proliferation, induced apoptosis and cell-cycle arrest, and inhibited the growth of human xenograft tumours and DEN-induced HCC in mice. Crucially, TKT depletion exerted identical effects to oroxylin A, and the promising inhibitor also exhibited excellent therapeutic efficacy against clinically relevant HCC PDOs. CONCLUSIONS: These results uncover a unique role for oroxylin A in TKT inhibition, which directly targets TKT and suppresses the non-oxidative PPP. Our findings will facilitate the development of small-molecule inhibitors of TKT and novel therapeutics for HCC.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Animais , Camundongos , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Transcetolase/genética , Transcetolase/metabolismo , Via de Pentose Fosfato , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/genética , Organoides/metabolismo , Organoides/patologia , Simulação de Acoplamento Molecular
7.
J Biol Chem ; 285(1): 705-12, 2010 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-19889637

RESUMO

Amyotrophic lateral sclerosis (ALS) is a fatal neuromuscular disorder characterized by degeneration of motor neurons and atrophy of skeletal muscle. Mutations in the superoxide dismutase (SOD1) gene are linked to 20% cases of inherited ALS. Mitochondrial dysfunction has been implicated in the pathogenic process, but how it contributes to muscle degeneration of ALS is not known. Here we identify a specific deficit in the cellular physiology of skeletal muscle derived from an ALS mouse model (G93A) with transgenic overexpression of the human SOD1(G93A) mutant. The G93A skeletal muscle fibers display localized loss of mitochondrial inner membrane potential in fiber segments near the neuromuscular junction. These defects occur in young G93A mice prior to disease onset. Fiber segments with depolarized mitochondria show greater osmotic stress-induced Ca(2+) release activity, which can include propagating Ca(2+) waves. These Ca(2+) waves are confined to regions of depolarized mitochondria and stop propagating shortly upon entering the regions of normal, polarized mitochondria. Uncoupling of mitochondrial membrane potential with FCCP or inhibition of mitochondrial Ca(2+) uptake by Ru360 lead to cell-wide propagation of such Ca(2+) release events. Our data reveal that mitochondria regulate Ca(2+) signaling in skeletal muscle, and loss of this capacity may contribute to the progression of muscle atrophy in ALS.


Assuntos
Esclerose Lateral Amiotrófica/metabolismo , Esclerose Lateral Amiotrófica/patologia , Sinalização do Cálcio , Espaço Intracelular/metabolismo , Mitocôndrias/patologia , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Animais , Cálcio/metabolismo , Sinalização do Cálcio/efeitos dos fármacos , Carbonil Cianeto p-Trifluormetoxifenil Hidrazona/farmacologia , Modelos Animais de Doenças , Espaço Intracelular/efeitos dos fármacos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/ultraestrutura , Modelos Biológicos , Fibras Musculares Esqueléticas/efeitos dos fármacos , Fibras Musculares Esqueléticas/metabolismo , Fibras Musculares Esqueléticas/patologia , Fibras Musculares Esqueléticas/ultraestrutura , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/ultraestrutura , Junção Neuromuscular/efeitos dos fármacos , Junção Neuromuscular/metabolismo , Junção Neuromuscular/patologia , Junção Neuromuscular/ultraestrutura , Compostos de Rutênio/farmacologia , Estresse Fisiológico/efeitos dos fármacos
8.
Commun Biol ; 4(1): 396, 2021 03 25.
Artigo em Inglês | MEDLINE | ID: mdl-33767386

RESUMO

CRISPR/Cas9-mediated genome editing provides potential for therapeutic development. Efficacy and long-term safety represent major concerns that remain to be adequately addressed in preclinical studies. Here we show that CRISPR/Cas9-mediated genome editing in two distinct SOD1-amyotrophic lateral sclerosis (ALS) transgenic mouse models prevented the development of ALS-like disease and pathology. The disease-linked transgene was effectively edited, with rare off-target editing events. We observed frequent large DNA deletions, ranging from a few hundred to several thousand base pairs. We determined that these large deletions were mediated by proximate identical sequences in Alu elements. No evidence of other diseases was observed beyond 2 years of age in these genome edited mice. Our data provide preclinical evidence of the efficacy and long-term safety of the CRISPR/Cas9 therapeutic approach. Moreover, the molecular mechanism of proximate identical sequences-mediated recombination provides mechanistic information to optimize therapeutic targeting design, and to avoid or minimize unintended and potentially deleterious recombination events.


Assuntos
Esclerose Lateral Amiotrófica/genética , Sistemas CRISPR-Cas/genética , Edição de Genes/estatística & dados numéricos , Superóxido Dismutase-1/genética , Sequência de Aminoácidos , Animais , Modelos Animais de Doenças , Camundongos , Camundongos Transgênicos , Superóxido Dismutase-1/química , Superóxido Dismutase-1/metabolismo
9.
Hum Mol Genet ; 17(15): 2310-9, 2008 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-18424447

RESUMO

Mutations in Cu,Zn superoxide dismutase (SOD1) are associated with amyotrophic lateral sclerosis (ALS). Among more than 100 ALS-associated SOD1 mutations, premature termination codon (PTC) mutations exclusively occur in exon 5, the last exon of SOD1. The molecular basis of ALS-associated toxicity of the mutant SOD1 is not fully understood. Here, we show that nonsense-mediated mRNA decay (NMD) underlies clearance of mutant mRNA with a PTC in the non-terminal exons. To further define the crucial ALS-associated SOD1 fragments, we designed and tested an exon-fusion approach using an artificial transgene SOD1(T116X) that harbors a PTC in exon 4. We found that the SOD1(T116X) transgene with a fused exon could escape NMD in cellular models. We generated a transgenic mouse model that overexpresses SOD1(T116X). This mouse model developed ALS-like phenotype and pathology. Thus, our data have demonstrated that a 'mini-SOD1' of only 115 amino acids is sufficient to cause ALS. This is the smallest ALS-causing SOD1 molecule currently defined. This proof of principle result suggests that the exon-fusion approach may have potential not only to further define a shorter ALS-associated SOD1 fragment, thus providing a molecular target for designing rational therapy, but also to dissect toxicities of other proteins encoded by genes of multiple exons through a 'gain of function' mechanism.


Assuntos
Esclerose Lateral Amiotrófica/enzimologia , Esclerose Lateral Amiotrófica/genética , Fusão Gênica Artificial/métodos , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo , Sequência de Aminoácidos/genética , Esclerose Lateral Amiotrófica/patologia , Animais , Códon sem Sentido , Análise Mutacional de DNA , Modelos Animais de Doenças , Éxons , Humanos , Camundongos , Camundongos Transgênicos , Estabilidade de RNA , RNA Mensageiro/metabolismo , Deleção de Sequência , Superóxido Dismutase-1
10.
Neurobiol Dis ; 29(3): 400-8, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18054242

RESUMO

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by the selective loss of motor neurons (MNs). Approximately 10% of ALS cases are familial (known as FALS), and approximately 20% of FALS cases are caused by mutations in Cu/Zn superoxide dismutase type 1 (SOD1). Mutant (MT) SOD1 induces FALS as a result of a toxicity that remains poorly defined. Several studies suggest that the toxicity involves a non-cell autonomous mechanism. In this study, we generated transgenic mice that had a restricted and repressible expression of MTSOD1 in spinal MNs and interneurons. Although the transgenic mice were not weak, they weighed less than control mice and had pathological and immunohistochemical abnormalities of MNs confined to cells that expressed MTSOD1. These results suggest that MTSOD1-induced MN degeneration is at least partly cell autonomous. Mouse models similar to the one presented here will be valuable for spatially and temporally controlling expression of mutant genes involved in neurodegenerative diseases.


Assuntos
Regulação Enzimológica da Expressão Gênica/fisiologia , Interneurônios/enzimologia , Neurônios Motores/enzimologia , Mutação/fisiologia , Superóxido Dismutase/biossíntese , Superóxido Dismutase/genética , Animais , Humanos , Interneurônios/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neurônios Motores/patologia , Superóxido Dismutase/fisiologia , Superóxido Dismutase-1
11.
Front Cell Neurosci ; 10: 216, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27703430

RESUMO

Frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) are believed to represent the different outcomes of a common pathogenic mechanism. However, while researchers have intensely studied the involvement of motor neurons in the ALS/FTD syndrome, very little is known about the function of hippocampal neurons, although this area is critical for memory and other cognitive functions. We investigated the electrophysiological properties of CA1 pyramidal cells in slices from 1 month-old UBQLN2P497H mice, a recently generated model of ALS/FTD that shows heavy depositions of ubiquilin2-positive aggregates in this brain region. We found that, compared to wild-type mice, cells from UBQLN2P497H mice were hypo-excitable. The amplitude of the glutamatergic currents elicited by afferent fiber stimulation was reduced by ~50%, but no change was detected in paired-pulse plasticity. The maximum firing frequency in response to depolarizing current injection was reduced by ~30%; the fast afterhyperpolarization in response to a range of depolarizations was reduced by almost 10 mV; the maximum slow afterhyperpolarization (sAHP) was also significantly decreased, likely in consequence of the decreased number of spikes. Finally, the action potential (AP) upstroke was blunted and the threshold depolarized compared to controls. Thus, synaptic and intrinsic excitability are both impaired in CA1 pyramidal cells of UBQLN2P497H mice, likely constituting a cellular mechanism for the cognitive impairments. Because these alterations are detectable before the establishment of overt pathology, we hypothesize that they may affect the further course of the disease.

12.
Arch Neurol ; 68(11): 1440-6, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22084127

RESUMO

BACKGROUND: The SQSTM1 gene encodes p62, a major pathologic protein involved in neurodegeneration. OBJECTIVE: To examine whether SQSTM1 mutations contribute to familial and sporadic amyotrophic lateral sclerosis (ALS). DESIGN: Case-control study. SETTING: Academic research. Patients  A cohort of 546 patients with familial (n = 340) or sporadic (n = 206) ALS seen at a major academic referral center were screened for SQSTM1 mutations. MAIN OUTCOME MEASURES: We evaluated the distribution of missense, deletion, silent, and intronic variants in SQSTM1 among our cohort of patients with ALS. In silico analysis of variants was performed to predict alterations in p62 structure and function. RESULTS: We identified 10 novel SQSTM1 mutations (9 heterozygous missense and 1 deletion) in 15 patients (6 with familial ALS and 9 with sporadic ALS). Predictive in silico analysis classified 8 of 9 missense variants as pathogenic. CONCLUSIONS: Using candidate gene identification based on prior biological knowledge and the functional prediction of rare variants, we identified several novel SQSTM1 mutations in patients with ALS. Our findings provide evidence of a direct genetic role for p62 in ALS pathogenesis and suggest that regulation of protein degradation pathways may represent an important therapeutic target in motor neuron degeneration.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Esclerose Lateral Amiotrófica/genética , Mutação/genética , Adulto , Idoso , Esclerose Lateral Amiotrófica/diagnóstico , Estudos de Casos e Controles , Estudos de Coortes , Feminino , Variação Genética/genética , Humanos , Masculino , Pessoa de Meia-Idade , Proteína Sequestossoma-1
13.
Hum Mol Genet ; 16(23): 2911-20, 2007 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-17855450

RESUMO

Mutations in Alsin are associated with chronic juvenile amyotrophic lateral sclerosis (ALS2), juvenile primary lateral sclerosis and infantile-onset ascending spastic paralysis. The primary pathology and pathogenic mechanism of the disease remain largely unknown. Here we show that alsin-deficient mice have motor impairment and degenerative pathology in the distal corticospinal tracts without apparent motor neuron pathology. Our data suggest that ALS2 is predominantly a distal axonopathy, rather than a neuronopathy in the central nervous system of the mouse model, implying that alsin plays an important role in maintaining the integrity of the corticospinal axons.


Assuntos
Axônios/patologia , Fatores de Troca do Nucleotídeo Guanina/deficiência , Sequência de Aminoácidos , Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/patologia , Esclerose Lateral Amiotrófica/fisiopatologia , Animais , Axônios/fisiologia , Encéfalo/patologia , Modelos Animais de Doenças , Éxons , Feminino , Fatores de Troca do Nucleotídeo Guanina/genética , Fatores de Troca do Nucleotídeo Guanina/fisiologia , Humanos , Masculino , Camundongos , Camundongos Knockout , Dados de Sequência Molecular , Neurônios Motores/patologia , Neurônios Motores/fisiologia , Mutação , Gravidez , Medula Espinal/patologia , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo , Superóxido Dismutase-1
14.
Proc Natl Acad Sci U S A ; 103(18): 7142-7, 2006 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-16636275

RESUMO

Twenty percent of the familial form of amyotrophic lateral sclerosis (ALS) is caused by mutations in the Cu, Zn-superoxide dismutase gene (SOD1) through the gain of a toxic function. The nature of this toxic function of mutant SOD1 has remained largely unknown. Here we show that WT SOD1 not only hastens onset of the ALS phenotype but can also convert an unaffected phenotype to an ALS phenotype in mutant SOD1 transgenic mouse models. Further analyses of the single- and double-transgenic mice revealed that conversion of mutant SOD1 from a soluble form to an aggregated and detergent-insoluble form was associated with development of the ALS phenotype in transgenic mice. Conversion of WT SOD1 from a soluble form to an aggregated and insoluble form also correlates with exacerbation of the disease or conversion to a disease phenotype in double-transgenic mice. This conversion, observed in the mitochondrial fraction of the spinal cord, involved formation of insoluble SOD1 dimers and multimers that are crosslinked through intermolecular disulfide bonds via oxidation of cysteine residues in SOD1. Our data thus show a molecular mechanism by which SOD1, an important protein in cellular defense against free radicals, is converted to aggregated and apparently ALS-associated toxic dimers and multimers by redox processes. These findings provide evidence of direct links among oxidation, protein aggregation, mitochondrial damage, and SOD1-mediated ALS, with possible applications to the aging process and other late-onset neurodegenerative disorders. Importantly, rational therapy based on these observations can now be developed and tested.


Assuntos
Esclerose Lateral Amiotrófica/enzimologia , Mitocôndrias/enzimologia , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo , Esclerose Lateral Amiotrófica/genética , Animais , Humanos , Camundongos , Camundongos Transgênicos , Mitocôndrias/ultraestrutura , Mutação , Fenótipo , Conformação Proteica , Medula Espinal/citologia , Superóxido Dismutase/química , Superóxido Dismutase-1 , Taxa de Sobrevida
15.
Se Pu ; 20(3): 216-8, 2002 May.
Artigo em Zh | MEDLINE | ID: mdl-12541939

RESUMO

Artificial neural networks have been applied for predicting the hydrophobic parameters of alkylbenzene. Compared with traditional methods it has the advantages of simple operation and wide applications. Based on error back propagation neural networks the relationship among the molecular connectivity index (chi), van der Waals surface area (Aw) and hydrophobic parameter was studied, meanwhile the mathematical model was established and used to predict the hydrophobic parameters. By comparing the hydrophobic parameters of experimental values with those calculated by neural networks, we found they had good agreement. The average relative deviation was less than 1%. Because traditional back propagation network is generally time consuming, resilient backpropagation (RPROP) algorithm was used to solve this problem. By using RPROP algorithm, the hydrophobic parameters were obtained precisely by fast training and simple parameter's selection. It needed less than 1,000 iterations to reach the goal on the computer operated at 1.4 GHz. The present work shows that the artificial neural network is a new powerful tool to predict the physicochemical parameters.


Assuntos
Cromatografia Líquida de Alta Pressão , Redes Neurais de Computação , Algoritmos , Benzeno/análise , Benzeno/química , Cromatografia Líquida de Alta Pressão/métodos , Previsões , Interações Hidrofóbicas e Hidrofílicas , Tolueno/análise , Tolueno/química
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