Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 36
Filtrar
1.
N Engl J Med ; 390(11): e27, 2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38466610
2.
J Org Chem ; 86(5): 4205-4219, 2021 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-33555865

RESUMO

Muqubilin, negombatoperoxide B, and negombatoperoxide C/D were synthesized through enantioselective routes, with the quaternary center derived from a peroxy chiral building block of known absolute configuration. The C-2/C-3 stereogenic centers were introduced by asymmetric aldol condensation, and the 1,2-dioxane ring was constructed via an intramolecular alkylation of a hydroperoxide with a mesylate. The synthetic samples showed physical and spectroscopic data consistent with those reported in the literature and thus verified the configurations of the natural products. A potentially more expeditious enantioselective entry to the 1,2-dioxane-aldol moiety (C-1 to C-6) of such cyclic peroxides was also briefly explored, where the C-2/C-3 stereogenic centers were installed through a [2+2] cycloaddition and the 1,2-dioxane ring was closed via an intramolecular alkylation coupled with an alkyl-oxygen cleavage of a ß-lactone.


Assuntos
Lactonas , Peróxidos , Alquilação , Reação de Cicloadição , Estereoisomerismo
3.
J Org Chem ; 85(15): 10007-10021, 2020 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-32790359

RESUMO

A range of allylic alcohols are shown to readily react with ethereal H2O2 in the presence of catalytic amounts of Na2MoO4-gly or MoO2(acac)2, affording the C═C trans hydroxylation-hydroperoxylation products in good yields with high regio- and stereoselectivity. Use of enantiomers of cyclic substrates resulted in corresponding enantiopure diol-tert-hydroperoxides. The possibility of further conversion of the diol-tert-hydroperoxides into triols or linear building blocks with an isolated tert-peroxy group containing a quaternary center is also exemplified.

4.
Med Sci Monit ; 25: 3247-3255, 2019 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-31048671

RESUMO

BACKGROUND Multiple myeloma (MM) is the second most common hematologic cancer with poor prognosis. Novel therapeutic strategies are needed to decrease the high mortality rate. The aim of this study was to identify prospective agents for MM. MATERIAL AND METHODS A microarray dataset was mined, which contains the transcriptome profiles of 588 MM patients. Univariate Cox analysis was performed to analyze the relationships between genes and clinical outcome. Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) were determined. Protective and risky genes were uploaded to Connectivity Map (CMAP) database to identify the potentially unknown effects of existing drugs. An example was selected to be docked on the known molecules. RESULTS A total of 1445 genes significantly correlated with the event free survival (EFS) of MM patients were identified and included 676 protective and 769 risky indicators. KEGG pathway analysis revealed that these prognosis-associated genes were enriched in the "cell cycle," "DNA replication," and "P53 signaling pathway". The top t3 most significant potential molecules were vorinostat, trifluoperazine, and thioridazine. CDK1 (cyclin-dependent kinase-1) ranked as the core in the class of prognosis-related genes in MM based on protein-protein interaction (PPI) network analysis. With Sybyl-X 2.0, the majority of the top 10 molecules aforementioned displayed high binding forces with CDK1. Among these molecules, trichostatin A had the greatest ability in combining with CDK1. CONCLUSIONS Genes that mainly accumulate in the cell cycle pathway play an essential role in the prognosis of MM, and these prognosis-related genes also have great value in drug development.


Assuntos
Reposicionamento de Medicamentos/métodos , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/genética , Biomarcadores Farmacológicos/análise , Biologia Computacional/métodos , Bases de Dados Genéticas , Perfilação da Expressão Gênica , Ontologia Genética , Redes Reguladoras de Genes , Humanos , Simulação de Acoplamento Molecular , Mieloma Múltiplo/metabolismo , Medicina de Precisão , Prognóstico , Intervalo Livre de Progressão , Modelos de Riscos Proporcionais , Estudos Prospectivos , Mapas de Interação de Proteínas , Transdução de Sinais , Transcriptoma
6.
Nucleic Acids Res ; 45(19): e163, 2017 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-28977529

RESUMO

A current question in the high-order organization of chromatin is whether topologically associating domains (TADs) are distinct from other hierarchical chromatin domains. However, due to the unclear TAD definition in tradition, the structural and functional uniqueness of TAD is not well studied. In this work, we refined TAD definition by further constraining TADs to the optimal separation on global intra-chromosomal interactions. Inspired by this constraint, we developed a novel method, called HiTAD, to detect hierarchical TADs from Hi-C chromatin interactions. HiTAD performs well in domain sensitivity, replicate reproducibility and inter cell-type conservation. With a novel domain-based alignment proposed by us, we defined several types of hierarchical TAD changes which were not systematically studied previously, and subsequently used them to reveal that TADs and sub-TADs differed statistically in correlating chromosomal compartment, replication timing and gene transcription. Finally, our work also has the implication that the refinement of TAD definition could be achieved by only utilizing chromatin interactions, at least in part. HiTAD is freely available online.


Assuntos
Algoritmos , Montagem e Desmontagem da Cromatina , Cromatina/genética , Cromatina/metabolismo , Biologia Computacional/métodos , Animais , Linhagem Celular , DNA/genética , DNA/metabolismo , Genoma/genética , Humanos , Células K562 , Reprodutibilidade dos Testes
7.
Med Sci Monit ; 24: 2025-2030, 2018 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-29621202

RESUMO

BACKGROUND The aim of this study was to explore the diagnostic value of sagittal measurement of thoracic inlet parameters for degenerative cervical spondylolisthesis (DCS). MATERIAL AND METHODS We initially included 65 patients with DCS and the same number of health people as the control group by using cervical radiograph evaluations. We analyzed the x-ray and computer tomographic (CT) data in prone and standing position at the same time. Measurement of cervical sagittal parameters was carried out in a standardized supine position. Multivariate logistic regression analysis was performed to evaluate these parameters as a diagnostic index for DCS. RESULTS There were 60 cases enrolled in the DCS group, and 62 cases included in the control group. The T1 slope and thoracic inlet angle (TIA) were significantly greater for the DCS group compared to the control group (24.33±2.85º versus 19.59±2.04º, p=0.00; 76.11±9.82º versus 72.86±7.31º, p=0.03, respectively). We observed no significant difference for the results of the neck tilt (NT), C2-C7 angle in the control and the DSC group (p>0.05). Logistic regression analysis and receiver operating characteristic (ROC) curve revealed that preoperative T1 slope of more than 22.0º showed significantly diagnostic value for the DCS group (p<0.05). CONCLUSIONS Patients with preoperative sagittal imbalance of thoracic inlet have a statistically significant increased risk of DCS. T1 slope of more than 22.0º showed significantly diagnostic value for the incidence of DCS.


Assuntos
Espondilose/diagnóstico por imagem , Adulto , Vértebras Cervicais/diagnóstico por imagem , Vértebras Cervicais/cirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pescoço , Doenças da Medula Espinal , Estenose Espinal , Espondilolistese/diagnóstico por imagem , Vértebras Torácicas/diagnóstico por imagem , Tomografia Computadorizada por Raios X
8.
Mol Biol Evol ; 33(9): 2368-75, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27297469

RESUMO

Ohnologs -paralogous gene pairs generated by whole genome duplication- are enriched for dosage sensitive genes, that is, genes that have a phenotype due to copy number changes. Dosage sensitive genes frequently occur in the same metabolic pathway and in physically interacting proteins. Accumulating evidence reveals that functionally related genes tend to co-localize in the three-dimensional (3D) arrangement of chromosomes. We query whether the spatial distribution of ohnologs has implications for their dosage balance. We analyzed the colocalization frequency of ohnologs based on chromatin interaction datasets of seven human cell lines and found that ohnolog pairs exhibit higher spatial proximity in 3D nuclear organization than other paralog pairs and than randomly chosen ohnologs in the genome. We also found that colocalized ohnologs are more resistant to copy number variations and more likely to be disease-associated genes, which indicates a stronger dosage balance in ohnologs with high spatial proximity. This phenomenon is further supported by the stronger similarity of gene co-expression and of gene ontology terms of colocalized ohnologs. In addition, for a large fraction of ohnologs, the spatial colocalization is conserved in mouse cells, suggestive of functional constraint on their 3D positioning in the nucleus.


Assuntos
Dosagem de Genes , Duplicação Gênica , Animais , Mapeamento Cromossômico/métodos , Variações do Número de Cópias de DNA , Evolução Molecular , Genoma Humano , Humanos , Camundongos , Fenótipo , Análise de Sequência de DNA/métodos , Análise Espacial
9.
Nucleic Acids Res ; 43(15): 7237-46, 2015 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-26150425

RESUMO

Recent chromosome conformation capture (3C) derived techniques have revealed that topologically associating domain (TAD) is a pervasive element in chromatin three-dimensional (3D) organization. However, there is currently no parameter to quantitatively measure the structural characteristics of TADs, thus obscuring our understanding on the structural and functional differences among TADs. Based on our finding that there exist intrinsic chromatin interaction patterns in TADs, we define a theoretical parameter, called aggregation preference (AP), to characterize TAD structures by capturing the interaction aggregation degree. Applying this defined parameter to 11 Hi-C data sets generated by both traditional and in situ Hi-C experimental pipelines, our analyses reveal that heterogeneous structures exist among TADs, and this structural heterogeneity is significantly correlated to DNA sequences, epigenomic signals and gene expressions. Although TADs can be stable in genomic positions across cell lines, structural comparisons show that a considerable number of stable TADs undergo significantly structural rearrangements during cell changes. Moreover, the structural change of TAD is tightly associated with its transcription remodeling. Altogether, the theoretical parameter defined in this work provides a quantitative method to link structural characteristics and biological functions of TADs, and this linkage implies that chromatin interaction pattern has the potential to mark transcription activity in TADs.


Assuntos
Cromatina/química , Genoma , Animais , Sequência de Bases , Linhagem Celular , DNA/química , Epigênese Genética , Genoma Humano , Humanos , Camundongos , Transcrição Gênica
10.
Zhongguo Zhong Yao Za Zhi ; 42(7): 1401-1406, 2017 Apr.
Artigo em Zh | MEDLINE | ID: mdl-29052406

RESUMO

In this paper, the status of adjuvant standard for Chinese materia medica processing in the Chinese Pharmacopoeia 2015 edition, the National Specification of Chinese Materia Medica Processing, and the 29 provincial specification of Chinese materia medica was summarized, and the the status including general requirements, specific requirements, and quality standard in the three grade official specifications was collected and analyzed according to the "medicine-adjuvant homology" and "food-adjuvant homology" features of adjuvants. This paper also introduced the research situation of adjuvant standard for Chinese materia medica processing in China; In addition, analyzed and discussed the problems existing in the standard system of adjuvant for Chinese materia medica processing, such as lack of general requirements, low level of standard, inconsistent standard references, and lack of research on the standard, and provided suggestions for the further establishment of the national standards system of adjuvant for Chinese materia medica processing.


Assuntos
Adjuvantes Farmacêuticos/normas , Materia Medica/normas , Medicina Tradicional Chinesa/normas , China
11.
Nucleic Acids Res ; 41(19): e183, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23965308

RESUMO

The 3D chromatin structure modeling by chromatin interactions derived from Hi-C experiments is significantly challenged by the intrinsic sequencing biases in these experiments. Conventional modeling methods only focus on the bias among different chromatin regions within the same experiment but neglect the bias arising from different experimental sequencing depth. We now show that the regional interaction bias is tightly coupled with the sequencing depth, and we further identify a chromatin structure parameter as the inherent characteristics of Hi-C derived data for chromatin regions. Then we present an approach for chromatin structure prediction capable of relaxing both kinds of sequencing biases by using this identified parameter. This method is validated by intra and inter cell-line comparisons among various chromatin regions for four human cell-lines (K562, GM12878, IMR90 and H1hESC), which shows that the openness of chromatin region is well correlated with chromatin function. This method has been executed by an automatic pipeline (AutoChrom3D) and thus can be conveniently used.


Assuntos
Cromatina/química , Modelos Moleculares , Linhagem Celular , Interpretação Estatística de Dados , Humanos , Células K562 , Análise de Sequência de DNA , Software
12.
World J Gastrointest Surg ; 16(3): 700-709, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38577087

RESUMO

BACKGROUND: Gastric cancer (GC) is the fifth most common type of cancer and has the fourth highest death rate among all cancers. There is a lack of studies examining the impact of liver metastases on the effectiveness of immunotherapy in individuals diagnosed with GC. AIM: To investigate the influence of liver metastases on the effectiveness and safety of immunotherapy in patients with advanced GC. METHODS: This retrospective investigation collected clinical data of patients with advanced stomach cancer who had immunotherapy at our hospital from February 2021 to January 2023. The baseline attributes were compared using either the Chi-square test or the Fisher exact probability method. The chi-square test and Kaplan-Meier survival analysis were employed to assess the therapeutic efficacy and survival duration in GC patients with and without liver metastases. RESULTS: The analysis comprised 48 patients diagnosed with advanced GC, who were categorized into two groups: A liver metastasis cohort (n = 20) and a non-liver metastatic cohort (n = 28). Patients with liver metastasis exhibited a more deteriorated physical condition compared to those without liver metastasis. The objective response rates in the cohort with metastasis and the cohort without metastasis were 15.0% and 35.7% (P > 0.05), respectively. Similarly, the disease control rates in these two cohorts were 65.0% and 82.1% (P > 0.05), respectively. The median progression-free survival was 5.0 months in one group and 11.2 months in the other group, with a hazard ratio of 0.40 and a significance level (P) less than 0.05. The median overall survival was 12.0 months in one group and 19.0 months in the other group, with a significance level (P) greater than 0.05. CONCLUSION: Immunotherapy is less effective in GC patients with liver metastases compared to those without liver metastasis.

13.
World J Gastrointest Surg ; 15(11): 2423-2429, 2023 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-38111773

RESUMO

BACKGROUND: Polycystic ovary syndrome (PCOS) is closely related to obesity, and weight loss can significantly improve the metabolic, endocrine and reproductive functions of obese individuals with PCOS. However, the efficacy of laparoscopic sleeve gastrectomy (LSG) for obesity with PCOS are unclear. AIM: The purpose of the study was to investigate the effect of LSG on related variables in obese patients with PCOS. METHODS: A retrospective analysis was performed on 32 obese patients with PCOS who received LSG treatment at the Third Hospital of Shanxi Medical University from 2013 to 2020. The changes in anthropometric indices, insulin, testosterone, estradiol, follicle stimulating hormone (FSH), luteinizing hormone (LH), menstrual cycle and LH/FSH ratio before and 1 mo, 3 mo, 6 mo and 12 mo after the operation were statistically analyzed. RESULTS: At 1 mo, 3 mo, 6 mo and 12 mo after surgery, the anthropometric indices, such as body weight and body mass index, of all patients were lower than those before the operation. The percentage excess weight loss (EWL%) at 1 mo, 3 mo, 6 mo and 1 year of follow-up were 25, 40, 46 and 65, respectively. The PCOS-related indices, such as insulin, testosterone, estradiol, follicle stimulating hormone (FSH), luteinizing hormone (LH) and menstrual cycle, were improved to varying degrees. During the 1-year follow-up, the average serum testosterone decreased from preoperative 0.72 ng/mL to 0.43 ng/mL (P < 0.05), average fasting insulin level (9.0 mIU/mL, preoperative 34.2 mil, LH level, 4.4 mIU/mL, preoperative 6.1 mIU/mL). The level of FSH (3.8 U/L, 4.8 U/p0.05) and the ratio of LH/FSH (0.7, 1.3/p0.05) were more relieved than those before surgery. During the postoperative follow-up, it was found that the menstrual cycle of 27 patients (nasty 27) returned to normal, and 6 patients (18%) who intended to become pregnant became pregnant within 1 year after surgery. CONCLUSION: The weight loss effect of LSG is obvious and affirmative, and the endocrine index of obese patients with PCOS is also improved to some extent, although the mechanism is not clear. Laparoscopic sleeve gastrectomy is expected to become a backup choice for patients with polycystic ovaries in the future.

14.
Biochim Biophys Acta ; 1812(11): 1472-6, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21791244

RESUMO

Retinitis pigmentosa, causing progressive blindness, is genetically heterogeneous. RP10, due to a defect in inosine monophosphate dehydrogenase 1 (IMPDH1), shows autosomal dominant inheritance. Recombinantly expressed clinical mutants show unaltered kinetic behaviour. It is unclear why reportedly impaired DNA binding is important and how it would explain negative dominance. An alternative view relates to the mutant proteins' tendency to aggregate. Regarding negative dominance, a key question is whether the defective protein can subvert the function of its normal counterpart in the same cell. Potentially, the homotetrameric structure of IMPDH1 might offer a vehicle for such an effect. We have established a reliable protocol for reproducible refolding of recombinantly expressed IMPDH1 in vitro. Clinical mutants R224P and D226N both show impaired folding. For equimolar mixtures of normal and mutant enzymes, independent refolding would predict activity regain midway between pure mutant and pure normal. Under various conditions regain is close to the mutant figure, suggesting that, in hybrid tetramers, mutant subunits impose their faulty conformation on normal partners. The observed molecular recruitment is a negative counterpart of the intra-allelic complementation, also mediated via oligomeric structure and postulated many years ago by Fincham. These findings appear potentially to account for the negative dominant inheritance. This interpretation must be provisional at present, as the predominant transcript in retina is an alternatively spliced version not fully identical to that used in our study. The results nevertheless have a general significance in pointing to a mechanism for negative dominance that could be widespread.


Assuntos
Genes Dominantes , IMP Desidrogenase/química , IMP Desidrogenase/genética , Proteínas Mutantes/genética , Mutação/genética , Dobramento de Proteína , Retinose Pigmentar/genética , Células Cultivadas , Dicroísmo Circular , Humanos , Corpos de Inclusão , Proteínas Mutantes/metabolismo , Multimerização Proteica , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Retina/metabolismo , Retina/patologia
15.
Disabil Rehabil ; 44(8): 1516-1523, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-33016146

RESUMO

PURPOSE: This study aimed to validate the simplified Chinese version of the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ) for Chinese patients with cervical spondylotic myelopathy (CSM). METHODS: The construct validity was conducted using confirmatory factor analysis (CFA). The convergent validity was based on factor loading, composite reliability (CR), and Pearson correlation coefficients (r). Internal consistency reliability was evaluated using Cronbach's α, test-retest reliability using intraclass correlation coefficients (ICC), and the ceiling and floor effects were also examined. RESULTS: A total of 168 native Chinese-speaking patients were enrolled. The CFA indicated that construct validity did not meet the preset criteria to be considered as good. Except for Q 4-1, the factor loading was higher than the standard of 0.5, and the CR values ranged from 0.70 to 0.85. Strong to moderate correlations were found between other scales and the simplified Chinese JOACMEQ. The scale showed good internal consistency reliability (Cronbach's α 0.639-0.821), and test-retest reliability (ICC 0.760-0.916). Moreover, the ceiling effect was displayed from Q1 to Q4. CONCLUSIONS: This study indicates that the simplified Chinese JOACMEQ is a reliable and valid measure of the functional status among Chinese patients with CSM.IMPLICATIONS FOR REHABILITATIONThe JOACMEQ was translated into the simplified Chinese and culturally adapted for Chinese-speaking patients with CSM for the first time.The simplified JOACMEQ demonstrated an excellent level of internal consistency and good test-retest reliability.The simplified Chinese JOACMEQ was reliable and valid for the measurement of the functional status among the patients with CSM.


Assuntos
Ortopedia , Doenças da Medula Espinal , China , Comparação Transcultural , Humanos , Japão , Psicometria , Reprodutibilidade dos Testes , Doenças da Medula Espinal/diagnóstico , Inquéritos e Questionários
16.
Biochim Biophys Acta ; 1792(8): 804-9, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19465117

RESUMO

Human glucose 6-phosphate dehydrogenase (G6PD) has both the "catalytic" NADP(+) site and a "structural" NADP(+) site where a number of severe G6PD deficiency mutations are located. Two pairs of G6PD clinical mutants, G6PD(Wisconsin) (R393G) and G6PD(Nashville) (R393H), and G6PD(Fukaya) (G488S) and G6PD(Campinas) (G488V), in which the mutations are in the vicinity of the "structural" NADP(+) site, showed elevated K(d) values of the "structural" NADP(+), ranging from 53 nM to 500 nM compared with 37 nM for the wild-type enzyme. These recombinant enzymes were denatured by Gdn-HCl and refolded by rapid dilution in the presence of l-Arg, NADP(+) and DTT at 25 degrees C. The refolding yields of the mutants exhibited strong NADP(+)-dependence and ranged from 1.5% to 59.4% with 1000 microM NADP(+), in all cases lower than the figure of 72% for the wild-type enzyme. These mutant enzymes also displayed decreased thermostability and high susceptibility to chymotrypsin digestion, in good agreement with their corresponding melting temperatures in CD experiments. Taken together, the results support the view that impaired binding of "structural" NADP(+) can hinder folding as well as cause instability of these clinical mutant enzymes in the fully folded state.


Assuntos
Glucosefosfato Desidrogenase , Mutação , NADP/metabolismo , Conformação Proteica , Dobramento de Proteína , Animais , Dicroísmo Circular , Estabilidade Enzimática , Glucosefosfato Desidrogenase/química , Glucosefosfato Desidrogenase/genética , Glucosefosfato Desidrogenase/metabolismo , Humanos , Recém-Nascido , Modelos Moleculares
17.
Mol Med Rep ; 21(3): 999-1010, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32016443

RESUMO

At present, the association between prognosis­associated long noncoding RNAs (lncRNAs) and mRNAs is yet to be reported in multiple myeloma (MM). The aim of the present study was to construct prognostic models with lncRNAs and mRNAs, and to map the interactions between these lncRNAs and mRNAs in MM. LncRNA and mRNA data from 559 patients with MM were acquired from the Genome Expression Omnibus (dataset GSE24080), and their prognostic values were calculated using the survival package in R. Multivariate Cox analysis was used on the top 20 most significant prognosis­associated mRNAs and lncRNAs to develop prognostic signatures. The performances of these prognostic signatures were tested using the survivalROC package in R, which allows for time­dependent receiver operator characteristic (ROC) curve estimation. Weighted correlation network analysis (WGCNA) was conducted to investigate the associations between lncRNAs and mRNAs, and a lncRNA­mRNA network was constructed using Cytoscape software. Univariate Cox regression analysis identified 39 lncRNAs and 1,445 mRNAs that were significantly associated with event­free survival of MM patients. The top 20 most significant survival­associated lncRNAs and mRNAs were selected as candidates for analyzing independent MM prognostic factors. Both signatures could be used to separate patients into two groups with distinct outcomes. The areas under the ROC curves were 0.739 for the lncRNA signature and 0.732 for the mRNA signature. In the lncRNA­mRNA network, a total of 143 mRNAs were positively or negatively associated with 23 prognosis­associated lncRNAs. NCRNA00201, LOC115110 and RP5­968J1.1 were the most dominant drivers. The present study constructed a model that predicted prognosis in MM and formed a network with the corresponding prognosis­associated mRNAs, providing a novel perspective for the clinical diagnosis and treatment of MM, and suggesting novel directions for interpreting the mechanisms underlying the development of MM.


Assuntos
Biologia Computacional , Mieloma Múltiplo/diagnóstico , RNA Longo não Codificante/genética , RNA Mensageiro/genética , Intervalo Livre de Doença , Perfilação da Expressão Gênica , Humanos , Estimativa de Kaplan-Meier , Mieloma Múltiplo/genética , Análise Multivariada , Análise de Sequência com Séries de Oligonucleotídeos , Prognóstico , Mapas de Interação de Proteínas , Curva ROC
18.
BMC Biotechnol ; 9: 19, 2009 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-19284595

RESUMO

BACKGROUND: Human glucose 6-phosphate dehydrogenase (G6PD), active in both dimer and tetramer forms, is the key entry enzyme in the pentose phosphate pathway (PPP), providing NADPH for biosynthesis and various other purposes, including protection against oxidative stress in erythrocytes. Accordingly haemolytic disease is a major consequence of G6PD deficiency mutations in man, and many severe disease phenotypes are attributed to G6PD folding problems. Therefore, a robust refolding method with high recovery yield and reproducibility is of particular importance to study those clinical mutant enzymes as well as to shed light generally on the refolding process of large multi-domain proteins. RESULTS: The effects of different chemical and physical variables on the refolding of human recombinant G6PD have been extensively investigated. L-Arg, NADP+ and DTT are all major positive influences on refolding, and temperature, protein concentration, salt types and other additives also have significant impacts. With the method described here, ~70% enzyme activity could be regained, with good reproducibility, after denaturation with Gdn-HCl, by rapid dilution of the protein, and the refolded enzyme displays kinetic and CD properties indistinguishable from those of the native protein. Refolding under these conditions is relatively slow, taking about 7 days to complete at room temperature even in the presence of cyclophilin A, a peptidylprolyl isomerase reported to increase refolding rates. The refolded protein intermediates shift from dominant monomer to dimer during this process, the gradual emergence of dimer correlating well with the regain of enzyme activity. CONCLUSION: L-Arg is the key player in the refolding of human G6PD, preventing the aggregation of folding intermediate, and NADP+ is essential for the folding intermediate to adopt native structure. The refolding protocol can be applied to produce high recovery yield of folded protein with unaltered properties, paving the way for future studies on clinical G6PD mutants with folding defects and providing a useful model system to study the folding process of oligomeric proteins.


Assuntos
Arginina/metabolismo , Glucosefosfato Desidrogenase/metabolismo , NADP/metabolismo , Dobramento de Proteína , Dicroísmo Circular , Ciclofilina A/metabolismo , Humanos , Cinética , Peso Molecular , Conformação Proteica , Desnaturação Proteica , Proteínas Recombinantes/metabolismo
19.
Oncol Lett ; 18(5): 5310-5324, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31612041

RESUMO

Autophagy has an important role in the pathogenesis of plasma cell development and multiple myeloma (MM); however, the prognostic role of autophagy-related genes (ARGs) in MM remains undefined. In the present study, the expression profiles of 234 ARGs were obtained from a Gene Expression Omnibus dataset (accession GSE24080), which contains 559 samples of patients with MM analyzed with 54,675 probes. Univariate Cox regression analysis identified 55 ARGs that were significantly associated with event-free survival of MM. Furthermore, a risk score with 16 survival-associated ARGs was developed using multivariate Cox regression analysis, including ATIC, BNIP3L, CALCOCO2, DNAJB1, DNAJB9, EIF4EBP1, EVA1A, FKBP1B, FOXO1, FOXO3, GABARAP, HIF1A, NCKAP1, PRKAR1A and SUPT20H, was constructed. Using this prognostic signature, patients with MM could be separated into high- and low-risk groups with distinct clinical outcomes. The area under the curve values for the receiver operating characteristic curves were 0.740, 0.741 and 0.712 for 3, 5 and 10 years prognosis predictions, respectively. Notably, the prognostic role of this risk score could be validated with another four independent cohorts (accessions: GSE57317, GSE4581, GSE4452 and GSE4204). In conclusion, ARGs may serve vital roles in the progression of MM, and the ARGs-based prognostic model may provide novel ideas for clinical applications in MM.

20.
Nat Plants ; 5(8): 822-832, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31383969

RESUMO

The non-random three-dimensional (3D) organization of the genome in the nucleus is critical to gene regulation and genome function. Using high-throughput chromatin conformation capture, we generated chromatin interaction maps for Brassica rapa and Brassica oleracea at a high resolution and characterized the conservation and divergence of chromatin organization in these two species. Large-scale chromatin structures, including A/B compartments and topologically associating domains, are notably conserved between B. rapa and B. oleracea, yet their KNOT structures are highly divergent. We found that genes retained in less fractionated subgenomes exhibited stronger interaction strengths, and diploidization-resistant duplicates retained in pairs or triplets are more likely to be colocalized in both B. rapa and B. oleracea. These observations suggest that spatial constraint in duplicated genes is correlated to their biased retention in the diploidization process. In addition, we found strong similarities in the epigenetic modification and Gene Ontology terms of colocalized paralogues, which were largely conserved across B. rapa and B. oleracea, indicating functional constraints on their 3D positioning in the nucleus. This study presents an investigation of the spatial organization of genomes in Brassica and provides insights on the role of 3D organization in the genome evolution of this genus.


Assuntos
Brassica/genética , Diploide , Genoma de Planta , Cromatina/química , Evolução Molecular , Conformação de Ácido Nucleico , Conformação Proteica , Mapas de Interação de Proteínas
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA