Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 49
Filtrar
1.
Clin Immunol ; : 110278, 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38878806

RESUMO

Nucleotide-binding leucine-rich repeat-containing receptor 12-associated autoinflammatory disease (NLRP12-AID) is a rare autosomal dominant disorder. In this study, we reported a case of this rare disease with a novel NLRP12 mutation (A218V, rs749659859). The patient displayed typical symptoms, including recurrent fever, arthralgia, and skin allergies. Elevated serum IgE, decreased apolipoprotein A1, high-density lipoprotein cholesterol, and fluctuating levels of various leukocyte subtypes, procalcitonin, IL6, creatine kinase, and 25-hydroxyvitamin D were also detected. Inflammatory lesions were observed in multiple organs using 18F-FDG PET/CT. By mining single-cell transcriptome data, we identified relatively high expression of NLRP12 in monocytes compared to other human peripheral blood mononuclear cells. NLRP12-positive monocytes exhibited reduced expression of IL18, CCL3, and TNFA compared to NLRP12-negative monocytes. Structural analyses suggested that the A218V mutation, along with A218T and F402L, may reduce the ATP-binding affinity of the NLRP12 protein. These findings may provide new insights into the mechanisms of NLRP12-AID, and suggest the potential ATP-based therapy for further investigation.

2.
Molecules ; 29(5)2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38474583

RESUMO

Tobacco etch virus protease (TEVp) is wildly exploited for various biotechnological applications. These applications take advantage of TEVp's ability to cleave specific substrate sequences to study protein function and interactions. A major limitation of this enzyme is its relatively slow catalytic rate. In this study, MD simulations were conducted on TEV enzymes and known highly active mutants (eTEV and uTEV3) to explore the relationship between mutation, conformation, and catalytic function. The results suggest that mutations distant from the active site can influence the substrate-binding pocket through interaction networks. MD analysis of eTEV demonstrates that, by stabilizing the orientation of the substrate at the catalytic site, mutations that appropriately enlarge the substrate-binding pocket will be beneficial for Kcat, enhancing the catalytic efficiency of the enzyme. On the contrary, mutations in uTEV3 reduced the flexibility of the active pocket and increased the hydrogen bonding between the substrate and enzyme, resulting in higher affinity. At the same time, the MD simulation demonstrates that mutations outside of the active site residues could affect the dynamic movement of the binding pocket by altering residue networks and communication pathways, thereby having a profound impact on reactivity. These findings not only provide a molecular mechanistic explanation for the excellent mutants, but also serve as a guiding framework for rational computational design.


Assuntos
Endopeptidases , Simulação de Dinâmica Molecular , Endopeptidases/metabolismo , Biotecnologia , Mutação
3.
J Trace Elem Med Biol ; 83: 127407, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38325182

RESUMO

BACKGROUND: Generally, decreased zinc in the serum of tumor patients but increased zinc in tumor cells can be observed. However, the role of zinc homeostasis in myeloid leukemia remains elusive. BCR-ABL is essential for the initiation, maintenance, and progression of chronic myelocytic leukemia (CML). We are currently investigating the association between zinc homeostasis and CML. METHODS: Genes involved in zinc homeostasis were examined using three GEO datasets. Western blotting and qPCR were used to investigate the effects of zinc depletion on BCR-ABL expression. Furthermore, the effect of TPEN on BCR-ABL promoter activity was determined using the dual-luciferase reporter assay. MRNA stability and protein stability of BCR-ABL were assessed using actinomycin D and cycloheximide. RESULTS: Transcriptome data mining revealed that zinc homeostasis-related genes were associated with CML progression and drug resistance. Several zinc homeostasis genes were affected by TPEN. Additionally, we found that zinc depletion by TPEN decreased BCR-ABL mRNA stability and transcriptional activity in K562 CML cells. Zinc supplementation and sodium nitroprusside treatment reversed BCR-ABL downregulation by TPEN, suggesting zinc- and nitric oxide-dependent mechanisms. CONCLUSION: Our in vitro findings may help to understand the role of zinc homeostasis in BCR-ABL regulation and thus highlight the importance of zinc homeostasis in CML.


Assuntos
Proteínas de Fusão bcr-abl , Leucemia Mielogênica Crônica BCR-ABL Positiva , Humanos , Apoptose , Etilenodiaminas/farmacologia , Proteínas de Fusão bcr-abl/genética , Proteínas de Fusão bcr-abl/metabolismo , Proteínas de Fusão bcr-abl/farmacologia , Genes abl , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Zinco/metabolismo
4.
Int J Biol Macromol ; 255: 128303, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37992939

RESUMO

Efficient synthetic routes for biomanufacturing chemicals often require the overcoming of pathway bottlenecks by tailoring enzymes to improve the catalytic efficiency or even implement non-native activities. 1,2,4-butanetriol (BTO), a valuable commodity chemical, is currently biosynthesized from D-xylose via a four-enzyme reaction cascade, with the ThDP-dependent α-keto acid decarboxylase (KdcA) identified as the potential bottleneck. Here, to further enhance the catalytic activity of KdcA toward the non-native substrate α-keto-3-deoxy-xylonate (KDX), in silico screening and structure-guided evolution were performed. The best mutants, S286L/G402P and V461K, exhibited a 1.8- and 2.5-fold higher enzymatic activity in the conversion of KDX to 3,4-dihydroxybutanal when compared to KdcA, respectively. MD simulations revealed that the two sets of mutations reshaped the substrate binding pocket, thereby increasing the binding affinity for KDX and promoting interactions between KDX and cofactor ThDP. Then, when the V461K mutant instead of wild type KdcA was integrated into the enzyme cascade, a 1.9-fold increase in BTO titer was observed. After optimization of the reaction conditions, the enzyme cocktail contained V461K converted 60 g/L D-xylose to 22.1 g/L BTO with a yield of 52.1 %. This work illustrated that protein engineering is a powerful tool for modifying the output of metabolic pathway.


Assuntos
Carboxiliases , Xilose , 3-Metil-2-Oxobutanoato Desidrogenase (Lipoamida)/genética , 3-Metil-2-Oxobutanoato Desidrogenase (Lipoamida)/metabolismo , Xilose/metabolismo , Butanóis , Carboxiliases/genética , Engenharia Metabólica
5.
Br J Pharmacol ; 181(11): 1614-1634, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38158217

RESUMO

BACKGROUND AND PURPOSE: Because of cervical cancer (CC) metastasis, the prognosis of diagnosed patients is poor. However, the molecular mechanisms and therapeutic approach for metastatic CC remain elusive. EXPERIMENTAL APPROACH: In this study, we first evaluated the effect of resveratrol (RSV) on CC cell migration and metastasis. Via an activity-based protein profiling (ABPP) approach, a photoaffinity probe of RSV (RSV-P) was synthesized, and the protein targets of RSV in HeLa cells were identified. Based on target information and subsequent in vivo and in vitro validation experiments, we finally elucidated the mechanism of RSV corresponding to its antimetastatic activity. KEY RESULTS: The results showed that RSV concentration-dependently suppressed CC cell migration and metastasis. A list of proteins was identified as the targets of RSV, through the ABPP approach with RSV-P, among which fatty acid binding protein 5 (FABP5) attracted our attention based on The Cancer Genome Atlas (TCGA) database analysis. Subsequent knockout and overexpression experiments confirmed that RSV directly interacted with FABP5 to inhibit fatty acid transport into the nucleus, thereby suppressing downstream matrix metalloproteinase-2 (MMP2) and matrix metalloproteinase-9 (MMP9) expression, thus inhibiting CC metastasis. CONCLUSIONS AND IMPLICATIONS: Our study confirmed the key role of FABP5 in CC metastasis and provided important target information for the design of therapeutic lead compounds for metastatic CC.


Assuntos
Proteínas de Ligação a Ácido Graxo , Ácidos Graxos , Resveratrol , Neoplasias do Colo do Útero , Humanos , Resveratrol/farmacologia , Neoplasias do Colo do Útero/tratamento farmacológico , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/metabolismo , Feminino , Proteínas de Ligação a Ácido Graxo/metabolismo , Proteínas de Ligação a Ácido Graxo/antagonistas & inibidores , Ácidos Graxos/metabolismo , Animais , Movimento Celular/efeitos dos fármacos , Células HeLa , Núcleo Celular/metabolismo , Núcleo Celular/efeitos dos fármacos , Metástase Neoplásica , Camundongos , Camundongos Nus , Camundongos Endogâmicos BALB C , Metaloproteinase 9 da Matriz/metabolismo , Relação Dose-Resposta a Droga
6.
Metallomics ; 15(5)2023 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-37061789

RESUMO

Zinc homeostasis is regulated by the SLC39A/ZIP, SLC30A/ZnT, and metallothionein (MT) protein families. The association of zinc homeostasis with acute myeloid leukemia (AML) is unclear. We previously demonstrated that zinc depletion by TPEN triggers apoptosis in NB4 AML cells with the degradation of PML-RARα oncoprotein, suggesting that zinc homeostasis may be associated with AML. The primary aim of this study was to explore the expression pattern and prognostic roles of zinc homeostasis-related genes in AML. Bioinformatics analyses were performed using integrated datasets from the TCGA and GTEx projects. The GEPIA tool was used to analyze the differential expression of zinc homeostasis-related genes. Correlations between zinc homeostasis-related genes were assessed with Spearman's correlation coefficient. OncoLnc was used to evaluate the prognostic roles of zinc homeostasis-related genes with Kaplan-Meier and Cox regression models. In both NB4 and U937 cells, the transcriptional regulation of zinc homeostasis-related genes by zinc depletion was detected through qPCR. We found that multiple ZIPs, ZnTs, and MTs were differentially expressed and correlated in AML tumors. In AML patients, higher expression of ZIP4 and lower expression of ZnT5 and ZnT7 predicted poorer survival. We further found that zinc depletion by TPEN upregulated ZIP7, ZIP9, ZIP10, ZIP13, and ZnT7 and downregulated ZIP14, ZnT1, ZnT6, and most of the positively expressed MTs in both NB4 and U937 AML cells. Our findings suggest high expression of ZIP4 and low expression of ZnT5 and ZnT7 as potential risk factors for the prognosis of AML. Zinc homeostasis may be a potential therapeutic target for AML, deserving further exploration.


Assuntos
Proteínas de Transporte de Cátions , Leucemia Mieloide Aguda , Humanos , Prognóstico , Proteínas de Transporte de Cátions/genética , Proteínas de Transporte de Cátions/metabolismo , Zinco/metabolismo , Retículo Endoplasmático/metabolismo , Leucemia Mieloide Aguda/genética , Homeostase/genética
7.
NPJ Precis Oncol ; 7(1): 28, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36922568

RESUMO

Genomic studies have demonstrated a high frequency of genetic alterations in components of the SWI/SNF complex including the core subunit SMARCA4. However, the mechanisms of tumorigenesis driven by SMARCA4 mutations, particularly in colorectal cancer (CRC), remain largely unknown. In this study, we identified a specific, hotspot mutation in SMARCA4 (c. 3721C>T) which results in a conversion from arginine to tryptophan at residue 1157 (R1157W) in human CRC tissues associated with higher-grade tumors and controls CRC progression. Mechanistically, we found that the SMARCA4R1157W mutation facilitated its recruitment to PRMT1-mediated H4R3me2a (asymmetric dimethylation of Arg 3 in histone H4) and enhanced the ATPase activity of SWI/SNF complex to remodel chromatin in CRC cells. We further showed that the SMARCA4R1157W mutant reinforced the transcriptional expression of EGFR and TNS4 to promote the proliferation of CRC cells and patient-derived tumor organoids. Importantly, we demonstrated that SMARCA4R1157W CRC cells and mutant cell-derived xenografts were more sensitive to the combined inhibition of PRMT1 and SMARCA4 which act synergistically to suppress cell proliferation. Together, our findings show that SMARCA4-R1157W is a critical activating mutation, which accelerates CRC progression through facilitating chromatin recruitment and remodeling. Our results suggest a potential precision therapeutic strategy for the treatment of CRC patients carrying the SMARCA4R1157W mutation.

8.
Front Med ; 16(6): 873-882, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36152127

RESUMO

Tumor growth is an angiogenesis-dependent process and accompanied by the formation of hypoxic areas. Tumstatin is a tumor-specific angiogenesis inhibitor that suppresses the proliferation and induces the apoptosis of tumorous vascular endothelial cells. VNP20009, an attenuated Salmonella typhimurium strain, preferentially accumulates in the hypoxic areas of solid tumors. In this study, a novel Salmonella-mediated targeted expression system of tumstatin (VNP-Tum5) was developed under the control of the hypoxia-induced J23100 promoter to obtain anti-tumor efficacy in mice. Treatment with VNP-Tum5 effectively suppressed tumor growth and prolonged survival in the mouse model of B16F10 melanoma. VNP-Tum5 exhibited a higher efficacy in inhibiting the proliferation and inducing the necrosis and apoptosis of B16F10 cells in vitro and in vivo compared with VNP (control). VNP-Tum5 significantly inhibited the proliferation and migration of mouse umbilical vascular endothelial cells to impede angiogenesis. VNP-Tum5 downregulated the expression of anti-vascular endothelial growth factor A, platelet endothelial cell adhesion molecule-1, phosphorylated phosphoinositide 3 kinase, and phosphorylated protein kinase B and upregulated the expression of cleaved-caspase 3 in tumor tissues. This study is the first to use tumstatin-transformed VNP20009 as a tumor-targeted system for treatment of melanoma by combining anti-tumor and anti-angiogenic effects.


Assuntos
Células Endoteliais , Melanoma , Animais , Camundongos , Células Endoteliais/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Linhagem Celular Tumoral , Apoptose , Melanoma/metabolismo , Inibidores da Angiogênese/farmacologia , Salmonella typhimurium/metabolismo , Modelos Animais de Doenças , Neovascularização Patológica , Proliferação de Células
9.
EMBO Rep ; 23(9): e54611, 2022 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-35833522

RESUMO

Inflammasomes are cytosolic multiprotein complexes that initiate host defense against bacterial pathogens. The nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) family caspase-associated recruitment domain-containing protein 4 (NLRC4) inflammasomes plays a critical role in the inflammatory response against intracellular bacterial infection. The NLR family apoptosis inhibitory proteins (NAIPs) detect Flagellin or type III secretion system (T3SS) microbial components to activate NLRC4 inflammasome. However, the underlying mechanism of NLRC4 inflammasome activation is not completely understood. Here, we show that the vitamin D receptor (VDR) is an essential immunological regulator of the NLRC4 inflammasome. Conditional VDR knockout mice (VDRflox/flox lyz2-Cre) exhibited impaired clearance of pathogens after acute Salmonella Typhimurium infection leading to poor survival. In macrophages, VDR deficiency reduced caspase-1 activation and IL-1ß secretion upon S. Typhimurium infection. For NAIPs act as upstream sensors for NLRC4 inflammasome assembly, the further study demonstrated that VDR promoted the NAIP-NLRC4 association and triggered NAIP-NLRC4 inflammasome activation, not NLRP3 activation. Moreover, Lys123 residue of VDR is identified as the critical amino acid for VDR-NLRC4 interaction, and the mutant VDR (K123A) effectively attenuates the NLRC4 inflammasome activation. Together, our findings suggest that VDR is a critical regulator of NAIPs-NLRC4 inflammasome activation, mediating innate immunity against bacterial infection.


Assuntos
Proteínas Reguladoras de Apoptose , Infecções Bacterianas , Proteínas de Ligação ao Cálcio , Inflamassomos , Receptores de Calcitriol , Animais , Proteínas Reguladoras de Apoptose/metabolismo , Proteínas Adaptadoras de Sinalização CARD/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , Caspases/metabolismo , Inflamassomos/metabolismo , Camundongos , Receptores de Calcitriol/genética , Receptores de Calcitriol/metabolismo
10.
Biotechnol Bioeng ; 119(8): 2105-2114, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35438195

RESUMO

EG5C-1, processive endoglucanase from Bacillus subtilis, is a typical bifunctional cellulase with endoglucanase and exoglucanase activities. The engineering of processive endoglucanase focuses on the catalytic pocket or carbohydrate-binding module tailoring based on sequence/structure information. Herein, a computational strategy was applied to identify the desired mutants in the enzyme molecule by evolutionary-coupling analysis; subsequently, four residue pairs were selected as evolutionary mutational hotspots. Based on iterative-saturation mutagenesis and subsequent enzymatic activity analysis, a superior mutant K51T/L93T has been identified away from the active center. This variant had increased specific activity from 4170 U/µmol of wild-type (WT) to 5678 U/µmol towards carboxymethyl cellulose-Na and an increase towards the substrate Avicel from 320 U/µmol in WT to 521 U/µmol. In addition, kinetic measurements suggested that superior mutant K51T/L93T had a high substrate affinity (Km ) and a remarkable improvement in catalytic efficiency (kcat /Km ). Furthermore, molecular dynamics simulations revealed that the K51T/L93T mutation altered the spatial conformation at the active site cleft, enhancing the interaction frequency between active site residues and substrate, and improving catalytic efficiency and substrate affinity. The current studies provided some perspectives on the effects of distal residue substitution, which might assist in the engineering of processive endoglucanase or other glycoside hydrolases.


Assuntos
Celulase , Aminoácidos , Bacillus subtilis/genética , Bacillus subtilis/metabolismo , Domínio Catalítico , Celulase/química , Celulose/metabolismo
11.
Int J Biol Macromol ; 171: 166-176, 2021 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-33421464

RESUMO

Exploring new multifunctional enzymes and understanding the mechanisms of catalytic promiscuity will be of enormous industrial and academic values. In the present study, we reported the discovery and characterization of a multifunctional enzyme BSGH13 from Bacillus subtilis BS-5. Remarkably, BSGH13 possessed α-amylase, endoglucanase, and xylanase activities. To our knowledge, this was the first report on an amylase from Bacillus species having additional endoglucanase and xylanase activities. Subsequently, we analyzed the effects of aromatic residues substitution at each site of the active site architecture on ligand-binding affinity and catalytic specificity of BSGH13 by a combination of virtual mutation and site-directed mutagenesis approaches. Our results indicated that the introduction of aromatic amino acids Phe or Trp at the positions L182 and L183 altered the local interaction network of BSGH13 towards different substrates, thus changing the multifunctional properties of BSGH13. Moreover, we provided an expanded perspective on studies of multifunctional enzymes.


Assuntos
Bacillus subtilis/química , Proteínas de Bactérias/química , Celulase/química , Endo-1,4-beta-Xilanases/química , alfa-Amilases/química , Substituição de Aminoácidos , Bacillus subtilis/enzimologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Domínio Catalítico , Celulase/genética , Celulase/metabolismo , Celulose/análogos & derivados , Celulose/química , Celulose/metabolismo , Clonagem Molecular , Endo-1,4-beta-Xilanases/genética , Endo-1,4-beta-Xilanases/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Cinética , Maltose/análogos & derivados , Maltose/química , Maltose/metabolismo , Modelos Moleculares , Mutação , Fenilalanina/química , Fenilalanina/genética , Fenilalanina/metabolismo , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Homologia Estrutural de Proteína , Relação Estrutura-Atividade , Especificidade por Substrato , Tetroses/química , Tetroses/metabolismo , Triptofano/química , Triptofano/genética , Triptofano/metabolismo , Xilanos/química , Xilanos/metabolismo , alfa-Amilases/genética , alfa-Amilases/metabolismo
12.
Int J Biol Macromol ; 168: 442-452, 2021 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-33310097

RESUMO

Processive endoglucanases possess both endo- and exoglucanase activity, making them attractive discovery and engineering targets. Here, a processive endoglucanase EG5C-1 from Bacillus subtilis was employed as the starting point for enzyme engineering. Referring to the complex structure information of EG5C-1 and cellohexaose, the amino acid residues in the active site architecture were identified and subjected to alanine scanning mutagenesis. The residues were chosen for a saturation mutagenesis since their variants showed similar activities to EG5C-1. Variants D70Q and S235W showed increased activity towards the substrates CMC and Avicel, an increase was further enhanced in D70Q/S235W double mutant, which displayed a 2.1- and 1.7-fold improvement in the hydrolytic activity towards CMC and Avicel, respectively. In addition, kinetic measurements showed that double mutant had higher substrate affinity (Km) and a significantly higher catalytic efficiency (kcat/Km). The binding isotherms of wild-type EG5C-1 and double mutant D70Q/S235W suggested that the binding capability of EG5C-1 for the insoluble substrate was weaker than that of D70Q/S235W. Molecular dynamics simulations suggested that the collaborative substitutions of D70Q and S235W altered the hydrogen bonding network within the active site architecture and introduced new hydrogen bonds between the enzyme and cellohexaose, thus enhancing both substrate affinity and catalytic efficiency.


Assuntos
Bacillus subtilis/enzimologia , Celulase/química , Celulase/metabolismo , Mutação , Bacillus subtilis/genética , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Domínio Catalítico , Celulase/genética , Ligação de Hidrogênio , Hidrólise , Cinética , Modelos Moleculares , Simulação de Dinâmica Molecular , Mutagênese Sítio-Dirigida , Oligossacarídeos/metabolismo , Engenharia de Proteínas , Especificidade por Substrato
13.
Front Immunol ; 11: 570524, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33117360

RESUMO

Liver fibrosis can result from various causes and could progress to cirrhosis and cancer; however, there are no effective treatments due to that its molecular mechanism is unclear. liver fibrosis model made by Schistosoma japonicum (S. japonicum) infection or Carbon tetrachloride (CCl4) intraperitoneal injection is a conventional model used in liver fibrosis-related studies for mechanism or pharmaceutical research purposes. But the differences in the pathological progression, immune responses and the underlying mechanism between the two liver fibrosis model have not been carefully compared and characterized, which hinders us from correctly understanding and making better use of the two models. In the present study, the pathological changes to the liver, and the cytokines, inflammatory factors, macrophages, and lymphocytes subsets involved were analyzed in the liver fibrosis model of S. japonicum infection or CCl4 intraperitoneal injection. Additionally, the pathological progression, immune responses and the underlying injury mechanism in these two models were compared and characterized. The results showed that the changing trend of interleukin-13 (IL-13), transforming growth factor beta (TGF-ß), inflammatory factors, and M1, M2 macrophages, were consistent with the development trend of fibrosis regardless of whether liver fibrosis was caused by S. japonicum or CCl4. For lymphocyte subsets, the proportions of CD3+ T cells and CD4+ T cells decreased gradually, while proportion of CD8+ T cells peaked at 6 weeks in mice infected with S. japonicum and at 12 weeks in mice injected with CCl4. With prolonged S. japonicum infection time, Th1 (CD4+IFN-γ+) immunity converted to Th2 (CD4+IL-4+)/Th17 (CD4+IL-17+) with weaker regulatory T cell (Treg) (CD4+CD25+FOXP3+) immunity. However, in liver fibrosis caused by CCl4, Th1 cells occupied the dominant position, while proportions of Th2, Th17, and Treg cells decreased gradually. In conclusion, liver fibrosis was a complex pathological process that was regulated by a series of cytokines and immune cells. The pathological progressions and immune responses to S. japonicum or CCl4 induced liver fibrosis were different, possibly because of their different injury mechanisms. The appropriate animal model should be selected according to the needs of different experiments and the pathogenic factors of liver fibrosis in the study.


Assuntos
Hepatite/imunologia , Fígado/imunologia , Schistosoma japonicum/fisiologia , Esquistossomose Japônica/imunologia , Subpopulações de Linfócitos T/imunologia , Células Th1/imunologia , Animais , Tetracloreto de Carbono/metabolismo , Células Cultivadas , Citocinas/metabolismo , Modelos Animais de Doenças , Progressão da Doença , Feminino , Fibrose , Humanos , Fígado/parasitologia , Fígado/patologia , Camundongos , Camundongos Endogâmicos C57BL
14.
Clin Biochem ; 84: 93-98, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32553579

RESUMO

BACKGROUND: Primary coenzyme Q10 deficiency refers to a group of diseases characterised by reduced levels of coenzyme Q10 in related tissues or cultured cells associated with the 9 genes involved in the biosynthesis of coenzyme Q10. A biallelic pathogenic variant of COQ8A gene causes the occurrence of the primary coenzyme Q10 deficiency type 4. The objective of this study was to investigate the genetic cause of muscle weakness in a proband who had a negative DMD gene test for Becker muscular dystrophy. METHODS: The DNA of the proband was sequenced using whole exome sequencing. With the help of the Human Phenotype Ontology (HPO), the range of related candidate pathogenic genes has been reduced to a certain extent based on "muscle weakness" (HP:0001324). In addition, family linkage analysis, phenotypic-genotype check and protein structure modeling were used to explore the genetic cause of the proband. RESULTS: The compound heterozygous variant c.836A > C (p.Gln279Pro) and c.1228C > T (p.Arg410Ter) in the COQ8A gene was identified in the proband. According to the 2015 American College of Medical Genetics and Genomics (ACMG) standards and guidelines for the interpretation of sequence variants, the novel variant c.836A > C could be classified as "likely pathogenic" for the proband. CONCLUSION: The p.Gln279Pro was detected in the KxGQ motif and the QKE triplet of the COQ8A protein, whose structures were crucial for the structure and function of the COQ8A protein associated with the biosynthesis of coenzyme Q10 and the proband's clinical symptoms were relatively milder than those previously reported.


Assuntos
Ataxia/genética , Doenças Mitocondriais/genética , Proteínas Mitocondriais/genética , Debilidade Muscular/genética , Ubiquinona/deficiência , Ataxia/metabolismo , Criança , Humanos , Masculino , Doenças Mitocondriais/metabolismo , Proteínas Mitocondriais/metabolismo , Debilidade Muscular/metabolismo , Mutação de Sentido Incorreto/genética , Linhagem , Ubiquinona/análogos & derivados , Ubiquinona/genética , Ubiquinona/metabolismo , Sequenciamento do Exoma
15.
Theranostics ; 10(10): 4437-4452, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32292506

RESUMO

The proto-oncogene c-Myc regulates multiple biological processes mainly through selectively activating gene expression. However, the mechanisms underlying c-Myc-mediated gene repression in the context of cancer remain less clear. This study aimed to clarify the role of PRMT5 in the transcriptional repression of c-Myc target genes in gastric cancer. Methods: Immunohistochemistry was used to evaluate the expression of PRMT5, c-Myc and target genes in gastric cancer patients. PRMT5 and c-Myc interaction was assessed by immunofluorescence, co-immunoprecipitation and GST pull-down assays. Bioinformatics analysis, immunoblotting, real-time PCR, chromatin immunoprecipitation, and rescue experiments were used to evaluate the mechanism. Results: We found that c-Myc directly interacts with protein arginine methyltransferase 5 (PRMT5) to transcriptionally repress the expression of a cohort of genes, including PTEN, CDKN2C (p18INK4C), CDKN1A (p21CIP1/WAF1), CDKN1C (p57KIP2) and p63, to promote gastric cancer cell growth. Specifically, we found that PRMT5 was required to promote gastric cancer cell growth in vitro and in vivo, and for transcriptional repression of this cohort of genes, which was dependent on its methyltransferase activity. Consistently, the promoters of this gene cohort were enriched for both PRMT5-mediated symmetric di-methylation of histone H4 on Arg 3 (H4R3me2s) and c-Myc, and c-Myc depletion also upregulated their expression. H4R3me2s also colocalized with the c-Myc-binding E-box motif (CANNTG) on these genes. We show that PRMT5 directly binds to c-Myc, and this binding is required for transcriptional repression of the target genes. Both c-Myc and PRMT5 expression levels were upregulated in primary human gastric cancer tissues, and their expression levels inversely correlated with clinical outcomes. Conclusions: Taken together, our study reveals a novel mechanism by which PRMT5-dependent transcriptional repression of c-Myc target genes is required for gastric cancer progression, and provides a potential new strategy for therapeutic targeting of gastric cancer.


Assuntos
Adenocarcinoma/metabolismo , Histonas/metabolismo , Proteína-Arginina N-Metiltransferases/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Neoplasias Gástricas/metabolismo , Adenocarcinoma/patologia , Linhagem Celular Tumoral , Progressão da Doença , Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Metilação , Regiões Promotoras Genéticas , Proto-Oncogene Mas , Neoplasias Gástricas/patologia
16.
Biomed Res Int ; 2018: 9483928, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29967790

RESUMO

Schistosomiasis is one of the world's major public health problems. Praziquantel is currently the only effective drug against schistosomiasis. As resistance of praziquantel has emerged in some endemic areas, development of new antischistosomal agents should be a high priority. In this study, a phage display peptide library was used for screening for peptide antagonists of thioredoxin glutathione reductase of Schistosoma japonicum (SjTGR), which has been identified as an alternative drug target. Three rounds of panning produced four different fusion phages. ELISA proved that all four phages could bind to SjTGR. One peptide, JIPDys1 (aa, WPHNWWPHFKVK), reduced enzyme activity of SjTGR by more than 50%. 2 µM of the synthesized peptide of JIPDys1 inhibited the activity of TrxR, GR, and Grx of SjTGR by 32.5%, 100%, and 100%, respectively. The IC50 values of the synthetic peptide JIPDys1 for TrxR, GR, and Grx were 3.67 µM, 0.11 µM, and 0.97 µM, respectively. Based on computer simulation, it appeared that JIPDys1 binds to the substrate binding sites of glutathione reductase (GR) and glutaredoxin (Grx). Our data show that the peptide, JIPDys1 (aa, WPHNWWPHFKVK), is a promising candidate to develop novel drugs against S. japonicum which acts by binding with SjTGR and reduces enzyme activity of SjTGR.


Assuntos
Simulação por Computador , Complexos Multienzimáticos/antagonistas & inibidores , NADH NADPH Oxirredutases/antagonistas & inibidores , Peptídeos , Schistosoma japonicum/enzimologia , Animais , Glutationa Redutase
17.
Acta Pharmacol Sin ; 39(9): 1421-1438, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29770796

RESUMO

Fufang Danshen (FFDS or Compound Danshen) consists of three Chinese herbs Danshen (Salviae miltiorrhizae radix et rhizome), Sanqi (Notoginseng radix et rhizome) and Tianranbingpian (Borneolum, or D-borneol), which has been show to significantly improve the function of the nervous system and brain metabolism. In this study we explored the possible mechanisms underlying the therapeutic effects of the combination of the effective components of FFDS (Tan IIA, NG-R1 and Borneol) in the treatment of Alzheimer's disease (AD) based on network pharmacology. We firstly constructed AD-related FFDS component protein interaction networks, and revealed that macrophage migration inhibitory factor (MIF) might regulate neuronal apoptosis through Bad in the progression of AD. Then we investigated the apoptosis-inducing effects of MIF and the impact of the effective components of FFDS in human neuroblastoma SH-SY5Y cells. We observed the characteristics of a "Pendular state" of MIF, where MIF (8 ng/mL) increased the ratio of p-Bad/Bad by activating Akt and the IKKα/ß signaling pathway to assure cell survival, whereas MIF (50 ng/mL) up-regulated the expression of Bad to trigger apoptosis of SH-SY5Y cells. MIF displayed neurotoxicity similar to Aß1-42, which was associated with the MIF-induced increased expression of Bad. Application of the FFDS composite solution significantly decreased the expression levels of Bad, suppressed MIF-induced apoptosis in SH-SY5Y cells. In a D-galactose- and AlCl3-induced AD mouse model, administration of the FFDS composite solution significantly improved the learning and memory, as well as neuronal morphology, and decreased the serum levels of INF-γ. Therefore, the FFDS composite solution exerts neuroprotective effects through down-regulating the level of Bad stimulated by MIF.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Apoptose/efeitos dos fármacos , Medicamentos de Ervas Chinesas/uso terapêutico , Oxirredutases Intramoleculares/metabolismo , Fatores Inibidores da Migração de Macrófagos/metabolismo , Fármacos Neuroprotetores/uso terapêutico , Animais , Linhagem Celular Tumoral , Humanos , Masculino , Camundongos Endogâmicos BALB C , Mapas de Interação de Proteínas/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Proteína de Morte Celular Associada a bcl/metabolismo
18.
Eur J Med Chem ; 151: 849-860, 2018 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-29684895

RESUMO

Xanthine oxidase, which catalyzes the oxidative reaction of hypoxanthine and xanthine into uric acid, is a key enzyme to the pathogenesis of hyperuricemia and gout. In this study, for the purpose of discovering novel xanthine oxidase (XO) inhibitors, a series of 2-arylbenzo[b]furan derivatives (3a-3d, 4a-4o and 6a-6d) were designed and synthesized. All these compounds were evaluated their xanthine oxidase inhibitory and antioxidant activities by using in vitro enzymatic assay and cellular model. The results showed that a majority of the designed compounds exhibited potent xanthine oxidase inhibitory effects and antioxidant activities, and compound 4a emerged as the most potent xanthine oxidase inhibitor (IC50 = 4.45 µM). Steady-state kinetic measurements of the inhibitor 4a with the bovine milk xanthine oxidase indicated a mixed type inhibition with 3.52 µM Ki and 13.14 µM Kis, respectively. The structure-activity relationship analyses have also been presented. Compound 4a exhibited the potent hypouricemic effect in the potassium oxonate-induced hyperuricemic mice model. A molecular docking study of compound 4a was performed to gain an insight into its binding mode with xanthine oxidase. These results highlight the identification of a new class of xanthine oxidase inhibitors that have potential to be more efficacious in treatment of gout.


Assuntos
Benzofuranos/química , Benzofuranos/farmacologia , Desenho de Fármacos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Xantina Oxidase/antagonistas & inibidores , Animais , Antioxidantes/química , Antioxidantes/farmacologia , Bovinos , Furanos , Masculino , Camundongos , Camundongos Endogâmicos ICR , Simulação de Acoplamento Molecular , Células RAW 264.7 , Relação Estrutura-Atividade , Xantina Oxidase/metabolismo
19.
Biochem Pharmacol ; 135: 126-138, 2017 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-28336257

RESUMO

The nuclear factor-κB (NF-κB)-mediated activation of macrophages plays a key role in mucosal immune responses in Crohn's disease (CD). Moreover, increasing evidence shows that the activation of peroxisome proliferator-activated receptor-γ (PPAR-γ) exerts satisfactory anti-inflammatory effects in experimental colitis models, mostly by suppressing NF-κB-mediated macrophage activation. Therefore, exploring therapeutic strategies to activate PPAR-γ and inhibit the NF-κB pathway in colonic macrophages holds great promise for the treatment of CD. In this study, five novel pyrazole-containing indolizine derivatives (B1, B2, B3, B4 and B5) were successfully synthesized and characterized, and their anti-inflammatory activities for CD treatment were also investigated. Among the five compounds, compound B4 effectively decreased the NF-κB-mediated production of the pro-inflammatory cytokine TNF-α in LPS-stimulated peritoneal macrophages. Moreover, compound B4 significantly ameliorated 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced mouse colitis symptoms, including body weight loss, colonic pathological damage and inflammatory cell infiltration. The results of western blotting and luciferase reporter assays indicated that compound B4 activated PPAR-γ and subsequently suppressed NF-κB activation. Conversely, the addition of the PPAR-γ antagonist GW9662 abrogated the anti-inflammatory effects of compound B4 both in vitro and in vivo. In summary, compound B4 activated the PPAR-γ pathway to inhibit downstream NF-κB signaling, which alleviated experimental colitis. Thus, this compound may serve as a potential therapeutic agent for patients with CD.


Assuntos
Colite/metabolismo , Indolizinas/uso terapêutico , NF-kappa B/metabolismo , PPAR gama/metabolismo , Pirazóis/uso terapêutico , Ácido Trinitrobenzenossulfônico/toxicidade , Anilidas/farmacologia , Animais , Colite/induzido quimicamente , Colite/prevenção & controle , Feminino , Indolizinas/farmacologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos ICR , NF-kappa B/antagonistas & inibidores , PPAR gama/antagonistas & inibidores , Substâncias Protetoras/farmacologia , Substâncias Protetoras/uso terapêutico , Pirazóis/farmacologia , Ácido Trinitrobenzenossulfônico/antagonistas & inibidores
20.
Bioresour Technol ; 229: 33-38, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28092734

RESUMO

To decrease d-Lactate production cost, wheat bran, a low-cost waste of milling industry, was selected as the sole feedstock. First, the nutrients were recovered from wheat bran by acid protease hydrolysis. Then, cellulosic hydrolysates were prepared from protease-treated samples after acid pretreatment and enzymatic saccharification. The combined use of nutrients and hydrolysates as nitrogen and carbon sources for fermentation by S. inulinus YB1-5 resulted in d-Lactate levels of 99.5g/L, with an average production efficiency of 1.94g/L/h and a yield of 0.89g/g glucose. Moreover, fed-batch simultaneous saccharification and fermentation process at 40°C, 20% (w/v) solid loading and 20FPU/g solid cellulase concentration was obtained. d-Lactate concentrations, yield, productivity, and optical purity were 87.3g/L, 0.65g/g glucose, 0.81g/L/h and 99.1%, respectively. This study provided a feasible procedure that can help produce cellulosic d-Lactate using agricultural waste without external nutrient supplementation.


Assuntos
Bacillales/metabolismo , Carboidratos/química , Fibras na Dieta/análise , Ácido Láctico/metabolismo , Técnicas de Cultura Celular por Lotes , Metabolismo dos Carboidratos , Celulase/metabolismo , Custos e Análise de Custo , Fermentação , Hidrólise , Peptídeo Hidrolases/metabolismo , Fatores de Tempo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA