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1.
New Phytol ; 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38742296

RESUMO

Arabidopsis Col-0 RPP2A and RPP2B confer recognition of Arabidopsis downy mildew (Hyaloperonospora arabidopsidis [Hpa]) isolate Cala2, but the identity of the recognized ATR2Cala2 effector was unknown. To reveal ATR2Cala2, an F2 population was generated from a cross between Hpa-Cala2 and Hpa-Noks1. We identified ATR2Cala2 as a non-canonical RxLR-type effector that carries a signal peptide, a dEER motif, and WY domains but no RxLR motif. Recognition of ATR2Cala2 and its effector function were verified by biolistic bombardment, ectopic expression and Hpa infection. ATR2Cala2 is recognized in accession Col-0 but not in Ler-0 in which RPP2A and RPP2B are absent. In ATR2Emoy2 and ATR2Noks1 alleles, a frameshift results in an early stop codon. RPP2A and RPP2B are essential for the recognition of ATR2Cala2. Stable and transient expression of ATR2Cala2 under 35S promoter in Arabidopsis and Nicotiana benthamiana enhances disease susceptibility. Two additional Col-0 TIR-NLR (TNL) genes (RPP2C and RPP2D) adjacent to RPP2A and RPP2B are quantitatively required for full resistance to Hpa-Cala2. We compared RPP2 haplotypes in multiple Arabidopsis accessions and showed that all four genes are present in all ATR2Cala2-recognizing accessions.

2.
J Exp Clin Cancer Res ; 43(1): 117, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38641672

RESUMO

BACKGROUND: Cholangiocarcinoma (CCA) is a highly malignant cancer of the biliary tract with poor prognosis. Further mechanistic insights into the molecular mechanisms of CCA are needed to develop more effective target therapy. METHODS: The expression of the histone lysine acetyltransferase KAT2B in human CCA was analyzed in human CCA tissues. CCA xenograft was developed by inoculation of human CCA cells with or without KAT2B overexpression into SCID mice. Western blotting, ChIP-qPCR, qRT-PCR, protein immunoprecipitation, GST pull-down and RNA-seq were performed to delineate KAT2B mechanisms of action in CCA. RESULTS: We identified KAT2B as a frequently downregulated histone acetyltransferase in human CCA. Downregulation of KAT2B was significantly associated with CCA disease progression and poor prognosis of CCA patients. The reduction of KAT2B expression in human CCA was attributed to gene copy number loss. In experimental systems, we demonstrated that overexpression of KAT2B suppressed CCA cell proliferation and colony formation in vitro and inhibits CCA growth in mice. Mechanistically, forced overexpression of KAT2B enhanced the expression of the tumor suppressor gene NF2, which is independent of its histone acetyltransferase activity. We showed that KAT2B was recruited to the promoter region of the NF2 gene via interaction with the transcription factor SP1, which led to enhanced transcription of the NF2 gene. KAT2B-induced NF2 resulted in subsequent inhibition of YAP activity, as reflected by reduced nuclear accumulation of oncogenic YAP and inhibition of YAP downstream genes. Depletion of NF2 was able to reverse KAT2B-induced reduction of nuclear YAP and subvert KAT2B-induced inhibition of CCA cell growth. CONCLUSIONS: This study provides the first evidence for an important tumor inhibitory effect of KAT2B in CCA through regulation of NF2-YAP signaling and suggests that this signaling cascade may be therapeutically targeted for CCA treatment.


Assuntos
Neoplasias dos Ductos Biliares , Colangiocarcinoma , Animais , Humanos , Camundongos , Neoplasias dos Ductos Biliares/genética , Ductos Biliares Intra-Hepáticos/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Colangiocarcinoma/patologia , Regulação Neoplásica da Expressão Gênica , Genes da Neurofibromatose 2 , Histonas/metabolismo , Lisina/metabolismo , Camundongos SCID , Fatores de Transcrição de p300-CBP/genética , Fatores de Transcrição de p300-CBP/metabolismo
3.
Cell Signal ; 113: 110917, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37813295

RESUMO

The conserved Hippo signalling pathway plays a crucial role in tumour formation by limiting tissue growth and proliferation. At the core of this pathway are tumour suppressor kinases STK3/4 and LATS1/2, which limit the activity of the oncogene YAP1, the primary downstream effector. Here, we employed a split TEV-based protein-protein interaction screen to assess the physical interactions among 28 key Hippo pathway components and potential upstream modulators. This screen led us to the discovery of TAOK2 as pivotal modulator of Hippo signalling, as it binds to the pathway's core kinases, STK3/4 and LATS1/2, and leads to their phosphorylation. Specifically, our findings revealed that TAOK2 binds to and phosphorylates LATS1, resulting in the reduction of YAP1 phosphorylation and subsequent transcription of oncogenes. Consequently, this decrease led to a decrease in cell proliferation and migration. Interestingly, a correlation was observed between reduced TAOK2 expression and decreased patient survival time in certain types of human cancers, including lung and kidney cancer as well as glioma. Moreover, in cellular models corresponding to these cancer types the downregulation of TAOK2 by CRISPR inhibition led to reduced phosphorylation of LATS1 and increased proliferation rates, supporting TAOK2's role as tumour suppressor gene. By contrast, overexpression of TAOK2 in these cellular models lead to increased phospho-LATS1 but reduced cell proliferation. As TAOK2 is a druggable kinase, targeting TAOK2 could serve as an attractive pharmacological approach to modulate cell growth and potentially offer strategies for combating cancer.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Humanos , Proliferação de Células , Via de Sinalização Hippo , Proteínas Serina-Treonina Quinases/metabolismo , Serina-Treonina Quinase 3 , Transdução de Sinais/genética
4.
J Exp Clin Cancer Res ; 42(1): 263, 2023 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-37817227

RESUMO

BACKGROUND: RNA N6-Methyladenosine (m6A) modification is implicated in the progression of human cancers including cholangiocarcinoma (CCA). METTL16 is recently identified as a new RNA methyltransferase responsible for m6A modification, although the role of METTL16 in CCA has not yet been examined. The current study aims to investigate the effect and mechanism of the RNA methyltransferase METTL16 in CCA. METHODS: The expression of METTL16 in CCA was examined by analyzing publicly available datasets or by IHC staining on tumor samples. siRNA or CRISPR/Cas9-mediated loss of function studies were performed in vitro and in vivo to investigate the oncogenic role of METTL16 in CCA. MeRIP-Seq was carried out to identify the downstream target of METTL16. ChIP-qPCR, immunoprecipitation, and immunoblots were used to explore the regulation mechanisms for METTL16 expression in CCA. RESULTS: We observed that the expression of METTL16 was noticeably increased in human CCA tissues. Depletion of METTL16 significantly inhibited CCA cell proliferation and decreased tumor progression. PRDM15 was identified as a key target of METTL16 in CCA cells. Mechanistically, our data showed that METTL16 regulated PRDM15 protein expression via YTHDF1-dependent translation. Accordingly, we observed that restoration of PRDM15 expression could rescue the deficiency of CCA cell proliferation/colony formation induced by METTL16 depletion. Our subsequent analyses revealed that METTL16-PRDM15 signaling regulated the expression of FGFR4 in CCA cells. Specifically, we observed that PRDM15 protein was associated with the FGFR4 promoter to regulate its expression. Furthermore, we showed that the histone acetyltransferase p300 cooperated with the transcription factor YY1 to regulate METTL16 gene expression via histone H3 lysine 27 (H3K27) acetylation in CCA cells. CONCLUSIONS: This study describes a novel METTL16-PRDM15-FGFR4 signaling axis which is crucial for CCA growth and may have important therapeutic implications. We showed that depletion of METTL16 significantly inhibited CCA cell proliferation and decreased tumor progression.


Assuntos
Neoplasias dos Ductos Biliares , Colangiocarcinoma , Humanos , Metiltransferases/genética , Metiltransferases/metabolismo , Linhagem Celular Tumoral , Colangiocarcinoma/patologia , RNA Interferente Pequeno , Ductos Biliares Intra-Hepáticos/metabolismo , Neoplasias dos Ductos Biliares/genética , Neoplasias dos Ductos Biliares/metabolismo , Receptor Tipo 4 de Fator de Crescimento de Fibroblastos/genética , Proteínas de Ligação a DNA , Fatores de Transcrição/genética
5.
Brain ; 146(8): 3172-3180, 2023 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-37082980

RESUMO

Multiple system atrophy (MSA) is a neurodegenerative disease characterized by the accumulation of misfolded α-synuclein (αSyn) and myelin disruption. However, the mechanism underlying αSyn accumulation in MSA brains remains unclear. Here, we aimed to identify epsin-2 as a potential regulator of αSyn propagation in MSA brains. In the MSA mouse model, PLP-hαSyn mice, and FABP7/αSyn hetero-aggregate-injected mice, we initially discovered that fatty acid-binding protein 7 (FABP7) is related to MSA development and forms hetero-aggregates with αSyn, which exhibit stronger toxicity than αSyn aggregates. Moreover, the injected FABP7/αSyn hetero-aggregates in mice selectively accumulated only in oligodendrocytes and Purkinje neurons, causing cerebellar dysfunction. Furthermore, bioinformatic analyses of whole blood from MSA patients and FABP7 knockdown mice revealed that epsin-2, a protein expressed in both oligodendrocytes and Purkinje cells, could potentially regulate FABP7/αSyn hetero-aggregate propagation via clathrin-dependent endocytosis. Lastly, adeno-associated virus type 5-dependent epsin-2 knockdown mice exhibited decreased levels of αSyn aggregate accumulation in Purkinje neurons and oligodendrocytes, as well as improved myelin levels and Purkinje neuron function in the cerebellum and motor performance. These findings suggest that epsin-2 plays a significant role in αSyn accumulation in MSA, and we propose epsin-2 as a novel therapeutic target for MSA.


Assuntos
Atrofia de Múltiplos Sistemas , Camundongos , Animais , alfa-Sinucleína/genética , alfa-Sinucleína/metabolismo , Proteína 7 de Ligação a Ácidos Graxos/metabolismo , Camundongos Transgênicos , Oligodendroglia/metabolismo , Encéfalo/metabolismo
6.
Food Res Int ; 168: 112735, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37120196

RESUMO

Aspergillus flavus (A. flavus) is a common saprophytic pathogenic fungus that produces toxic and carcinogenic aflatoxins prone to contaminate food. Here, we optimized the synthesis method of Ar-turmerone, the main active ingredient in turmeric essential oil, improved its yield and reduced the operation requirements. Moreover, 50.0 µg/mL Ar-turmerone 100.0 % inhibited the colonies growth, spore germination, mycelium biomass and aflatoxin accumulation in 7 days. 2,018 differentially expressed genes (DEGs) such as catA, ppoC, erg7, erg6 and aflO related to the A. flavus growth and aflatoxin product were significantly downregulated including 45 DEGs were 100.0 % suppressed. Besides, Ar-turmerone greatly reduced A. flavus in maize, the optimal storage conditions for maize to avoid A. flavus contamination were determined as 0.940 aw, 400.0 µg/mL Ar-turmerone, and 16.0 °C. Satisfactory odor, luster, taste, and mildew in maize observed after three weeks of storage under the optimal conditions. Thus, Ar-turmerone can be used as a potential food antifungal agent against A. flavus growth and aflatoxin accumulation during food storage.


Assuntos
Aflatoxinas , Aspergillus flavus , Aflatoxinas/análise , Antifúngicos/farmacologia , Zea mays/genética , Sementes/química
7.
Proc Natl Acad Sci U S A ; 120(7): e2217114120, 2023 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-36753463

RESUMO

Nicotinamide adenine dinucleotide (NAD+) has emerged as a key component in prokaryotic and eukaryotic immune systems. The recent discovery that Toll/interleukin-1 receptor (TIR) proteins function as NAD+ hydrolases (NADase) links NAD+-derived small molecules with immune signaling. We investigated pathogen manipulation of host NAD+ metabolism as a virulence strategy. Using the pangenome of the model bacterial pathogen Pseudomonas syringae, we conducted a structure-based similarity search from 35,000 orthogroups for type III effectors (T3Es) with potential NADase activity. Thirteen T3Es, including five newly identified candidates, were identified that possess domain(s) characteristic of seven NAD+-hydrolyzing enzyme families. Most Pseudomonas syringae strains that depend on the type III secretion system to cause disease, encode at least one NAD+-manipulating T3E, and many have several. We experimentally confirmed the type III-dependent secretion of a novel T3E, named HopBY, which shows structural similarity to both TIR and adenosine diphosphate ribose (ADPR) cyclase. Homologs of HopBY were predicted to be type VI effectors in diverse bacterial species, indicating potential recruitment of this activity by microbial proteins secreted during various interspecies interactions. HopBY efficiently hydrolyzes NAD+ and specifically produces 2'cADPR, which can also be produced by TIR immune receptors of plants and by other bacteria. Intriguingly, this effector promoted bacterial virulence, indicating that 2'cADPR may not be the signaling molecule that directly initiates immunity. This study highlights a host-pathogen battleground centered around NAD+ metabolism and provides insight into the NAD+-derived molecules involved in plant immunity.


Assuntos
ADP-Ribose Cíclica , NAD , Virulência , NAD/metabolismo , ADP-Ribose Cíclica/metabolismo , Bactérias/metabolismo , Plantas/metabolismo , Pseudomonas syringae/metabolismo , NAD+ Nucleosidase/genética , NAD+ Nucleosidase/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Doenças das Plantas/microbiologia
8.
Am J Pathol ; 192(12): 1712-1724, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36456043

RESUMO

Cholangiocarcinoma (CCA) is a highly malignant cancer of the biliary tree. Although studies have implicated enhancer of Zeste homolog 2 (EZH2) in CCA growth, the role of EZH2 in CCA development has not been investigated, and the mechanism for EZH2-regulated gene expression in CCA remains to be further defined. The current study used a mouse model of CCA induced by hydrodynamic tail vein injection of Notch1 intracellular domain and myristoylated-AKT plasmids. Mice with liver-specific EZH2 knockout displayed reduced CCA development. In a xenograft model, EZH2 knockdown significantly decreased CCA progression. Administration of the EZH2 inhibitor GSK126 decreased CCA tumor burden in mice. Accordingly, EZH2 depletion or inhibition reduced the growth and colony formation capability of CCA cells. Analysis of high-throughput data identified a set of 12 tumor-inhibiting genes as targets of EZH2 in CCA. The experimental results suggest that EZH2 may down-regulate these tumor-inhibiting genes through methylation of lysine 27 on histone H3 (H3K27) in the gene louses and through regulation of specific miRNAs. High mobility group box 1 was shown to facilitate the methyltransferase activity of EZH2, which is implicated in the regulation of CCA cell growth. The study shows that EZH2 promotes CCA development and progression through a complicated regulatory network involving tumor-inhibiting genes, miRNAs, and high mobility group box 1, which support targeting EZH2 as a potentially effective strategy for CCA treatment.


Assuntos
Neoplasias dos Ductos Biliares , Colangiocarcinoma , MicroRNAs , Animais , Humanos , Camundongos , Neoplasias dos Ductos Biliares/genética , Ductos Biliares Intra-Hepáticos , Colangiocarcinoma/genética , Modelos Animais de Doenças , Regulação para Baixo , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Genes Supressores de Tumor , Histonas , Metilação , MicroRNAs/genética
9.
Theranostics ; 12(14): 6422-6436, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36168634

RESUMO

Rationale: Messenger RNA (mRNA) vaccine outperforms other kinds of cancer immunotherapy due to its high response rates, easy preparation, and wide applicability, which is considered as one of the most promising forms of next-generation cancer therapies. However, the inherent instability and insufficient protein expression duration of mRNA limit the efficacy and widespread application of the vaccine. Methods: Here, we first tested the possibility of a novel circular RNA (circRNA) platform for protein expression and compare its duration with linear RNA. Then, we developed a lipid nanoparticle (LNP) system for circRNA delivery in vitro and in vivo. Next, the innate and adaptive immune response of circRNA-LNP complex was evaluated in vivo. The anti-tumor efficacy of circRNA-LNP was further confirmed in three tumor models. Finally, the possibility of combination therapy with circRNA-LNP and adoptive cell transfer therapy was further investigated in a late-stage tumor model. Results: We successfully increased the stability of the RNA vaccine by circularizing the linear RNA molecules to form highly stable circRNA molecules which exhibited durable protein expression ability. By encapsulating the antigen-coding circRNA in LNP enabling in vivo expression, we established a novel circRNA vaccine platform, which was capable of triggering robust innate and adaptive immune activation and showed superior anti-tumor efficacy in multiple mouse tumor models. Conclusions: Overall, our circRNA vaccine platform provides a novel prospect for the development of cancer RNA vaccines in a wide range of hard-to-treat malignancies.


Assuntos
Vacinas Anticâncer , Nanopartículas , Neoplasias , Animais , Lipossomos , Camundongos , Neoplasias/terapia , RNA/genética , RNA Circular/genética , RNA Mensageiro/genética , Vacinas Sintéticas , Vacinas de mRNA
10.
Am J Physiol Cell Physiol ; 323(4): C1190-C1205, 2022 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-36036444

RESUMO

N6-methyladenosine (m6A) is the most prevalent internal modification in eukaryotic RNAs. This modification is regulated by three different factors (writers, erasers, and readers) and affects multiple aspects of RNA metabolism, including RNA splicing, nuclear export, translation, stability and decay. The m6A-mediated modification plays important roles in posttranscriptional regulation of gene expression and mediates a variety of cellular and biological processes. Accordingly, deregulation in m6A modification is closely related to the occurrence and development of human diseases. The liver is the largest digestive and metabolic organ in human and recent studies have shown that m6A modification is importantly implicated in liver cellular and physiological functions and in the pathogenesis of hepatic diseases and cancers. In the current review, we summarize the functions of m6A in RNA metabolism and its roles in liver cell biology and discuss its implication in hepatic diseases and carcinogenesis.


Assuntos
Adenosina , Fígado , Adenosina/genética , Adenosina/metabolismo , Biologia , Carcinogênese/genética , Carcinogênese/metabolismo , Humanos , Fígado/metabolismo , RNA/genética , RNA/metabolismo
11.
Anal Chem ; 94(28): 10109-10117, 2022 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-35802615

RESUMO

Tumor recurrence commonly results from tumor-positive resection margins and metastatic lesions. The complete removal of tumor-positive margins is particularly essential in clinics. Thus, we designed a strategy based on Escherichia coli Nissle 1917 (EcN) nitroreductase (NTR) with a polyethylene glycol (PEG) polymer coating (PC-EcN-NTR) to specifically target and colonize in tumors for high-contrast tumor imaging by providing a large amount of NTR as biomarkers in situ. NTR is a favorable biomarker for tumor detection and imaging. The nfsB-encoding plasmid with a 16S promoter was transfected into EcN for the continuous and stable expression of NTR (E. coli. NfsB). PC-EcN-NTR can accumulate and proliferate for a long time in tumors to substantially express NTR. When the NTR-activated fluorescence (FL) probe was sprayed on the tumor, the tumor region showed fluorescence signals within 5 min. Compared to the tumor without colonization with bacteria, the PC-EcN-NTR-colonized tumors displayed 3.15× enhanced fluorescence signals. Furthermore, the fluorescence signals of the whole tumor can last at least 3 h, which is suitable for a long and meticulous surgical operation. More importantly, in the PC-EcN-NTR-harboring tumor, obvious FL appeared even at the very edge (approximately 200 µm away from the edge) of the tumor tissue. A TCF-Based near-infrared-II fluorescent probe (probe 2) was designed and synthesized. Results similar to those of probe 1 were observed when probe 2 was used for in vivo tumor imaging, which further proved the generality of the enhancing ability of the tumor-targeting probiotic. This strategy will hopefully guide the surgical resection of tumors via monitoring intense NTR activity. It may spur the use of tumor-targeting probiotic and enzyme-activated fluorescent probes for the processes of tumor diagnosis and image-guided surgery.


Assuntos
Neoplasias , Probióticos , Cirurgia Assistida por Computador , Biomarcadores , Escherichia coli/metabolismo , Corantes Fluorescentes/metabolismo , Humanos , Neoplasias/diagnóstico por imagem , Neoplasias/cirurgia , Nitrorredutases/metabolismo
12.
Plant Cell ; 34(9): 3443-3459, 2022 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-35699507

RESUMO

Phytophthora effector PSR1 suppresses small RNA (sRNA)-mediated immunity in plants, but the underlying mechanism remains unknown. Here, we show that Phytophthora suppressor of RNA silencing 1 (PSR1) contributes to the pathogenicity of Phytophthora sojae and specifically binds to three conserved C-terminal domains of the eukaryotic PSR1-Interacting Protein 1 (PINP1). PINP1 encodes PRP16, a core pre-mRNA splicing factor that unwinds RNA duplexes and binds to primary microRNA transcripts and general RNAs. Intriguingly, PSR1 decreased both RNA helicase and RNA-binding activity of PINP1, thereby dampening sRNA biogenesis and RNA metabolism. The PSR1-PINP1 interaction caused global changes in alternative splicing (AS). A total of 5,135 genes simultaneously exhibited mis-splicing in both PSR1-overexpressing and PINP1-silenced plants. AS upregulated many mRNA transcripts that had their introns retained. The high occurrence of intron retention in AS-induced transcripts significantly promoted Phytophthora pathogen infection in Nicotiana benthamiana, and this might be caused by the production of truncated proteins. Taken together, our findings reveal a key role for PINP1 in regulating sRNA biogenesis and plant immunity.


Assuntos
Phytophthora , Pequeno RNA não Traduzido , Doenças das Plantas , Imunidade Vegetal , Plantas , Precursores de RNA , Glycine max
13.
J Gastrointest Oncol ; 13(1): 49-55, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35284130

RESUMO

Background: To explore the imaging characteristics of esophageal cancer in multi-slice spiral CT (MSCT) and barium meal radiography and to analyze the value of the two examinations alone or in combination for cancer staging diagnosis. Methods: The clinical data of 87 patients with esophageal cancer admitted to our hospital from June 2018 to June 2020 were retrospectively analyzed. According to the different examination methods, they were divided into a barium meal group (n=28 cases, X-ray barium meal radiography), an MSCT group (n=29 cases, MSCT examination), and a combined group (n=30 cases, barium meal + MSCT). The imaging characteristics from the barium meal radiography and MSCT alone versus their combined results were compared with the pathological examination results to analyze their accuracy in diagnosing esophageal cancer staging. Results: Of the 87 cases, the esophageal cancer lesion sites were as follows: 23 cervical cases, 20 upper thoracic cases, 21 middle thoracic cases, and 23 lower thoracic cases. The X-ray barium meal examination of esophageal mucosa showed irregular filling of the esophagus. The esophageal wall was stiff or jagged, the lumen was narrow, and it was difficult for the barium to pass, the mucosa was discontinuous. The CT scan showed irregular thickening of the esophageal wall, eccentric and concentric stenosis of the esophageal cavity, and the upper part of the esophagus showed different degrees of expansion. The trachea and bronchi were invaded, deformed, and displaced under compression. The diagnostic staging results of the barium meal group and MSCT group were inconsistent with the pathological results (Kappa =0.105, 0.112; P>0.05). The diagnostic staging results of the combined group were in good agreement with the pathological results (Kappa =0.769). In addition, the accuracy of the combined group in the diagnosis of stage III-IV esophageal cancer among the three groups was significantly higher than that of the barium meal group and MSCT group alone (P<0.05). Conclusions: MSCT and barium meal radiography clearly display the imaging features of esophageal cancer and can provide reliable imaging evidence for preoperative diagnosis; the combination of both measures can effectively improve the accuracy of early diagnosis for esophageal cancer.

14.
Protein Sci ; 31(2): 432-442, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34767267

RESUMO

Antibiotic resistance is a continually growing challenge in the treatment of various bacterial infections worldwide. New drugs and new drug targets are necessary to curb the threat of infectious diseases caused by multidrug-resistant pathogens. The tryptophan biosynthesis pathway is essential for bacterial growth but is absent in higher animals and humans. Drugs that can inhibit the bacterial biosynthesis of tryptophan offer a new class of antibiotics. In this work, we combined a structure-based strategy using in silico docking screening and molecular dynamics (MD) simulations to identify compounds targeting the α subunit of tryptophan synthase with experimental methods involving the whole-cell minimum inhibitory concentration (MIC) test, solution state NMR, and crystallography to confirm the inhibition of L-tryptophan biosynthesis. Screening 1,800 compounds from the National Cancer Institute Diversity Set I against α subunit revealed 28 compounds for experimental validation; four of the 28 hit compounds showed promising activity in MIC testing. We performed solution state NMR experiments to demonstrate that a one successful inhibitor, 3-amino-3-imino-2-phenyldiazenylpropanamide (Compound 1) binds to the α subunit. We also report a crystal structure of Salmonella enterica serotype Typhimurium tryptophan synthase in complex with Compound 1 which revealed a binding site at the αß interface of the dimeric enzyme. MD simulations were carried out to examine two binding sites for the compound. Our results show that this small molecule inhibitor could be a promising lead for future drug development.


Assuntos
Antibacterianos , Triptofano Sintase , Antibacterianos/química , Antibacterianos/farmacologia , Sítios de Ligação , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Triptofano Sintase/antagonistas & inibidores , Triptofano Sintase/química
15.
Mol Cancer Res ; 20(3): 350-360, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-34880125

RESUMO

Cholangiocarcinoma (CCA) is a lethal malignancy with few therapeutic options. NAD+-dependent 15-hydroxyprostaglandin dehydrogenase (15-PGDH) has been shown to inhibit CCA cell growth in vitro and in xenograft models. However, the role of 15-PGDH in CCA development has not been investigated and the mechanism for 15-PGDH gene regulation remains unclear. Here, we evaluated the role of 15-PGDH in CCA development by using a mouse model with hydrodynamic tail vein injection of transposase-based plasmids expressing Notch1 intracellular domain and myr-Akt, with or without co-injection of 15-PGDH expression plasmids. Our results reveal that 15-PGDH overexpression effectively prevents CCA development. Through patient data mining and experimental approaches, we provide novel evidences that 15-PGDH is epigenetically silenced by histone methyltransferase G9a. We observe that 15-PGDH and G9a expressions are inversely correlated in both human and mouse CCAs. By using CCA cells and mouse models, we show that G9a inhibition restores 15-PGDH expression and inhibited CCA in vitro and in vivo. Mechanistically, our data indicate that G9a is recruited to 15-PGDH gene promoter via protein-protein interaction with the E-box binding Myc/Max heterodimer. The recruited G9a then silences 15-PGDH gene through enhanced methylation of H3K9. Our further experiments have led to the identification of STAT4 as a key transcription factor involved in the regulation of 15-PGDH by G9a. Collectively, our findings disclose a novel G9a-15PGDH signaling axis which is importantly implicated in CCA development and progression. IMPLICATIONS: The current study describes a novel G9a-15PGDH signaling axis which is importantly implicated in CCA development and progression.


Assuntos
Neoplasias dos Ductos Biliares , Colangiocarcinoma , Neoplasias dos Ductos Biliares/tratamento farmacológico , Neoplasias dos Ductos Biliares/genética , Neoplasias dos Ductos Biliares/patologia , Ductos Biliares Intra-Hepáticos/metabolismo , Ductos Biliares Intra-Hepáticos/patologia , Colangiocarcinoma/patologia , Epigênese Genética , Antígenos de Histocompatibilidade/genética , Histona Metiltransferases/genética , Histona Metiltransferases/metabolismo , Histona-Lisina N-Metiltransferase/genética , Histona-Lisina N-Metiltransferase/metabolismo , Humanos , Hidroxiprostaglandina Desidrogenases
16.
J Oncol ; 2021: 4405697, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34675976

RESUMO

The present study aimed to analyze the effects of acetylation-related lncRNAs in non-small-cell lung cancer (NSCLC). A total of 399 differentially expressed lncRNAs (DElncRNAs) have been identified between 497 NSCLC tissues and 54 normal tissues in the TCGA database, and 105 of which were correlated with acetylation regulators. By using univariate cox regression analysis and combining it with clinical prognosis information, 12 prognostic-related lncRNAs were selected for the subsequent analysis. The NSCLC patients were divided into two subgroups (cluster 1 and cluster 2) by clustering software, and immunocyte infiltration analysis, microenvironmental analysis, and clinical relevance analysis were performed between the two subgroups. A risk model was also built to further assess the prognosis value of prognostic-related lncRNAs in NSCLC patients. We found that AC099850.3 was significantly higher in both cluster 1 and high-risk subgroups, which may serve as a potential biomarker for the prognosis of NSCLC patients. Then, based on ceRNA competition mechanisms, the pathway enrichment of 105 acetylation-related lncRNAs was conducted by GO and KEGG analyses. We found the acetylation-related lncRNAs were primarily enriched in MAPK and EGFR signaling pathways, which were closely associated with NSCLC development. Finally, we validated the expression levels of AC099850.3 in NSCLC tissues and adjacent non-cancerous tissues and confirmed that AC099850.3 was significantly highly expressed in NSCLC tissues and cells. These results may provide clues for our understanding of the role of acetylation-related lncRNAs and valuable information for future clinical diagnosis and prognosis in NSCLC patients.

17.
PLoS Biol ; 19(8): e3001136, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34424903

RESUMO

In plants, nucleotide-binding domain and leucine-rich repeat (NLR)-containing proteins can form receptor networks to confer hypersensitive cell death and innate immunity. One class of NLRs, known as NLR required for cell death (NRCs), are central nodes in a complex network that protects against multiple pathogens and comprises up to half of the NLRome of solanaceous plants. Given the prevalence of this NLR network, we hypothesised that pathogens convergently evolved to secrete effectors that target NRC activities. To test this, we screened a library of 165 bacterial, oomycete, nematode, and aphid effectors for their capacity to suppress the cell death response triggered by the NRC-dependent disease resistance proteins Prf and Rpi-blb2. Among 5 of the identified suppressors, 1 cyst nematode protein and 1 oomycete protein suppress the activity of autoimmune mutants of NRC2 and NRC3, but not NRC4, indicating that they specifically counteract a subset of NRC proteins independently of their sensor NLR partners. Whereas the cyst nematode effector SPRYSEC15 binds the nucleotide-binding domain of NRC2 and NRC3, the oomycete effector AVRcap1b suppresses the response of these NRCs via the membrane trafficking-associated protein NbTOL9a (Target of Myb 1-like protein 9a). We conclude that plant pathogens have evolved to counteract central nodes of the NRC immune receptor network through different mechanisms. Coevolution with pathogen effectors may have driven NRC diversification into functionally redundant nodes in a massively expanded NLR network.


Assuntos
Evolução Biológica , Proteínas de Helminto/fisiologia , Interações Hospedeiro-Patógeno/fisiologia , Proteínas NLR/fisiologia , Solanaceae/microbiologia , Morte Celular , Resistência à Doença
18.
Acta Biochim Biophys Sin (Shanghai) ; 53(1): 102-111, 2021 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-33128543

RESUMO

Currently, there remains a great need to elucidate the molecular mechanism of acute myocardial infarction in order to facilitate the development of novel therapy. Inhibitor of apoptosis-stimulating protein of p53 (iASPP) is a member of the ASPP family proteins and an evolutionarily preserved inhibitor of p53 that is involved in many cellular processes, including apoptosis of cancer cells. The purpose of this study was to investigate the possible role of iASPP in acute myocardial infarction. The protein level of iASPP was markedly reduced in the ischemic hearts in vivo and hydrogen peroxide-exposed cardiomyocytes in vitro. Overexpression of iASPP reduced the infarct size and cardiomyocyte apoptosis of mice subjected to 24 h of coronary artery ligation. Echocardiography showed that cardiac function was improved as indicated by the increase in ejection fraction and fractional shortening. In contrast, knockdown of iASPP exacerbated cardiac injury as manifested by impaired cardiac function, increased infarct size, and apoptosis rate. Mechanistically, overexpression of iASPP inhibited, while knockdown of iASPP increased the expressions of p53 and Bax, the key regulators of apoptosis. Taken together, our results suggested that iASPP is an important regulator of cardiomyocyte apoptosis, which represents a potential target in the therapy of myocardial infarction.


Assuntos
Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Isquemia Miocárdica/genética , Isquemia Miocárdica/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Proteína Supressora de Tumor p53/antagonistas & inibidores , Animais , Apoptose/genética , Modelos Animais de Doenças , Regulação para Baixo , Técnicas de Silenciamento de Genes , Traumatismos Cardíacos/genética , Traumatismos Cardíacos/patologia , Traumatismos Cardíacos/prevenção & controle , Peróxido de Hidrogênio/toxicidade , Masculino , Camundongos Endogâmicos C57BL , Isquemia Miocárdica/etiologia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Cultura Primária de Células , Proteína X Associada a bcl-2/metabolismo
19.
Mol Plant Microbe Interact ; 33(12): 1394-1404, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32986514

RESUMO

Sec-delivered effector 1 (SDE1) from the huanglongbing (HLB)-associated bacterium 'Candidatus Liberibacter asiaticus' was previously characterized as an inhibitor of defense-related, papain-like cysteine proteases in vitro and in planta. Here, we investigated the contributions of SDE1 to HLB progression. We found that SDE1 expression in the model plant Arabidopsis thaliana caused severe yellowing in mature leaves, reminiscent of both 'Ca. L. asiaticus' infection symptoms and accelerated leaf senescence. Induction of senescence signatures was also observed in the SDE1-expressing A. thaliana lines. These signatures were apparent in older leaves but not in seedlings, suggesting an age-associated effect. Furthermore, independent lines of transgenic Citrus paradisi (L.) Macfadyen (Duncan grapefruit) that express SDE1 exhibited hypersusceptibility to 'Ca. L. asiaticus'. Similar to A. thaliana, transgenic citrus expressing SDE1 showed altered expression of senescence-associated genes, but only after infection with 'Ca. L. asiaticus'. These findings suggest that SDE1 is a virulence factor that contributes to HLB progression, likely by inducing premature or accelerated senescence in citrus. This work provides new insight into HLB pathogenesis.[Formula: see text] Copyright © 2020 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.


Assuntos
Citrus , Liberibacter , Doenças das Plantas , Arabidopsis/microbiologia , Citrus/microbiologia , Liberibacter/genética , Liberibacter/metabolismo , Liberibacter/patogenicidade , Doenças das Plantas/microbiologia , Folhas de Planta/microbiologia , Fatores de Virulência/genética , Fatores de Virulência/metabolismo
20.
Plant Physiol ; 184(2): 792-805, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32759268

RESUMO

Citrus Huanglongbing (HLB), caused by Candidatus Liberibacter asiaticus (Las), is one of the most destructive citrus diseases worldwide, yet how Las causes HLB is poorly understood. Here we show that a Las-secreted protein, SDE15 (CLIBASIA_04025), suppresses plant immunity and promotes Las multiplication. Transgenic expression of SDE15 in Duncan grapefruit (Citrus × paradisi) suppresses the hypersensitive response induced by Xanthomonas citri ssp. citri (Xcc) and reduces the expression of immunity-related genes. SDE15 also suppresses the hypersensitive response triggered by the Xanthomonas vesicatoria effector protein AvrBsT in Nicotiana benthamiana, suggesting that it may be a broad-spectrum suppressor of plant immunity. SDE15 interacts with the citrus protein CsACD2, a homolog of Arabidopsis (Arabidopsis thaliana) ACCELERATED CELL DEATH 2 (ACD2). SDE15 suppression of plant immunity is dependent on CsACD2, and overexpression of CsACD2 in citrus suppresses plant immunity and promotes Las multiplication, phenocopying overexpression of SDE15. Identification of CsACD2 as a susceptibility target has implications in genome editing for novel plant resistance against devastating HLB.


Assuntos
Proteínas Reguladoras de Apoptose/fisiologia , Proteínas de Arabidopsis/fisiologia , Proteínas de Bactérias/fisiologia , Citrus sinensis/imunologia , Interações Hospedeiro-Patógeno/imunologia , Liberibacter/fisiologia , Oxirredutases/fisiologia , Proteínas de Bactérias/isolamento & purificação , Citrus sinensis/metabolismo , Imunidade Vegetal , Plantas Geneticamente Modificadas
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