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1.
Cell ; 185(8): 1325-1345.e22, 2022 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-35366418

RESUMO

Protein aggregation is a hallmark of multiple human pathologies. Autophagy selectively degrades protein aggregates via aggrephagy. How selectivity is achieved has been elusive. Here, we identify the chaperonin subunit CCT2 as an autophagy receptor regulating the clearance of aggregation-prone proteins in the cell and the mouse brain. CCT2 associates with aggregation-prone proteins independent of cargo ubiquitination and interacts with autophagosome marker ATG8s through a non-classical VLIR motif. In addition, CCT2 regulates aggrephagy independently of the ubiquitin-binding receptors (P62, NBR1, and TAX1BP1) or chaperone-mediated autophagy. Unlike P62, NBR1, and TAX1BP1, which facilitate the clearance of protein condensates with liquidity, CCT2 specifically promotes the autophagic degradation of protein aggregates with little liquidity (solid aggregates). Furthermore, aggregation-prone protein accumulation induces the functional switch of CCT2 from a chaperone subunit to an autophagy receptor by promoting CCT2 monomer formation, which exposes the VLIR to ATG8s interaction and, therefore, enables the autophagic function.


Assuntos
Chaperonina com TCP-1 , Macroautofagia , Agregados Proteicos , Animais , Camundongos , Proteínas Reguladoras de Apoptose/metabolismo , Autofagia/fisiologia , Proteínas de Transporte/metabolismo , Chaperonina com TCP-1/metabolismo , Proteína Sequestossoma-1/metabolismo
2.
Cell ; 181(3): 637-652.e15, 2020 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-32272059

RESUMO

Many cytosolic proteins lacking a signal peptide, called leaderless cargoes, are secreted through unconventional secretion. Vesicle trafficking is a major pathway involved. It is unclear how leaderless cargoes enter into the vesicle. Here, we find a translocation pathway regulating vesicle entry and secretion of leaderless cargoes. We identify TMED10 as a protein channel for the vesicle entry and secretion of many leaderless cargoes. The interaction of TMED10 C-terminal region with a motif in the cargo accounts for the selective release of the cargoes. In an in vitro reconstitution assay, TMED10 directly mediates the membrane translocation of leaderless cargoes into the liposome, which is dependent on protein unfolding and enhanced by HSP90s. In the cell, TMED10 localizes on the endoplasmic reticulum (ER)-Golgi intermediate compartment and directs the entry of cargoes into this compartment. Furthermore, cargo induces the formation of TMED10 homo-oligomers which may act as a protein channel for cargo translocation.


Assuntos
Sistemas de Translocação de Proteínas/metabolismo , Proteínas de Transporte Vesicular/metabolismo , Animais , Transporte Biológico , Linhagem Celular , Linhagem Celular Tumoral , Membrana Celular/metabolismo , Citosol/metabolismo , Retículo Endoplasmático/metabolismo , Complexo de Golgi/metabolismo , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Sinais Direcionadores de Proteínas , Sistemas de Translocação de Proteínas/fisiologia , Transporte Proteico/fisiologia , Proteínas/metabolismo , Via Secretória , Proteínas de Transporte Vesicular/fisiologia
3.
Nat Chem Biol ; 2024 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-39232187

RESUMO

Protein phosphorylation is a pivotal post-translational modification modulating various cellular processes. In Gram-positive bacteria, the protein arginine kinase McsB, along with its activator McsA, has a key role in labeling misfolded and damaged proteins during stress. However, the activation mechanism of McsB by McsA remains elusive. Here we report the cryo-electron microscopy structure of a tetrameric McsA-McsB complex at 3.41 Å resolution. Biochemical analysis indicates that the homotetrameric assembly is essential for McsB's kinase activity. The conserved C-terminal zinc finger of McsA interacts with an extended loop in McsB, optimally orienting a critical catalytic cysteine residue. In addition, McsA binding decreases the CtsR's affinity for McsB, enhancing McsB's kinase activity and accelerating the turnover rate of CtsR phosphorylation. Furthermore, McsA binding also increases McsB's thermostability, ensuring its activity under heat stress. These findings elucidate the structural basis and activation mechanism of McsB in stress response.

4.
BMC Plant Biol ; 24(1): 698, 2024 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-39044176

RESUMO

Cold stress can impact plant biology at both the molecular and morphological levels. We cultivated two different types of tobacco seedlings using distinct seeding methods, observing significant differences in their cold tolerance at 4 °C. After 12 h cold stress, shallow water seeding cultivation treatment demonstrates a relatively good growth state with slight wilting of the leaves. Tobacco grown using the float system exhibited short, thick roots, while those cultivated through shallow water seeding had elongated roots with more tips and forks. After cold stress, the shallow water seeding cultivation treatment demonstrated higher antioxidant enzyme activity, and lower malondialdehyde (MDA) content.Transcriptome analysis was performed on the leaves of these tobacco seedlings at three stages of cold treatment (before cold stress, after cold stress, and after 3 days of recovery). Upon analyzing the raw data, we found that the shallow water seeding cultivation treatment was associated with significant functional enrichment of nicotinamide adenine dinucleotide (NAD) biosynthesis and NAD metabolism before cold stress, enrichment of functions related to the maintenance of cellular structure after cold stress, and substantial functional enrichment related to photosynthesis during the recovery period. Weighted gene co-expression network analysis (WGCNA) was conducted, identifying several hub genes that may contribute to the differences in cold tolerance between the two tobacco seedlings. Hub genes related to energy conversion were predominantly identified in shallow water seeding cultivation treatment during our analysis, surpassing findings in other areas. These include the AS gene, which controls the synthesis of NAD precursors, the PED1 gene, closely associated with fatty acid ß-oxidation, and the RROP1 gene, related to ATP production.Overall, our study provides a valuable theoretical basis for exploring improved methods of cultivating tobacco seedlings. Through transcriptome sequencing technology, we have elucidated the differences in gene expression in different tobacco seedlings at three time points, identifying key genes affecting cold tolerance in tobacco and providing possibilities for future gene editing.


Assuntos
Nicotiana , Plântula , Água , Nicotiana/genética , Nicotiana/fisiologia , Nicotiana/crescimento & desenvolvimento , Plântula/genética , Plântula/crescimento & desenvolvimento , Plântula/fisiologia , Água/metabolismo , Resposta ao Choque Frio/genética , Resposta ao Choque Frio/fisiologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Temperatura Baixa
5.
BMC Cancer ; 24(1): 1087, 2024 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-39223584

RESUMO

BACKGROUND: Our research endeavored to develop a robust predictive signature grounded in super-enhancer-related genes (SERGs), with the dual objectives of forecasting survival outcomes and evaluating the tumor immune microenvironment (TiME) in hepatocellular carcinoma (HCC). METHODS: HCC RNA-sequencing data were retrieved from The Cancer Genome Atlas (TCGA), and 365 patients were randomly assigned to training or testing sets in 1:1 ratio. SERGs of HCC were downloaded from Super-Enhancer Database (SEdb). On the basis of training set, a SERGs signature was identified, and its prognostic value was confirmed by internal and external validation (GSE14520) sets. We subsequently examined the model for potential functional enrichment and the degree of tumor immune infiltration. Additionally, we carried out in vitro experiments to delve into the biological functions of CBX2 gene. RESULTS: An SE-related prognostic model including CBX2, TPX2, EFNA3, DNASE1L3 and SOCS2 was established and validated. According to this risk model, patients in the high-risk group had a significantly worse prognosis, and their immune cell infiltration was significantly different from that of low-risk group. Moreover, the high-risk group exhibited a significant enrichment of tumor-associated pathological pathways. The SERGs signature can generally be utilized to screen HCC patients who are likely to respond to immunotherapy, as there is a positive correlation between the risk score and the Tumor Immune Dysfunction and Exclusion (TIDE) score. Furthermore, the downregulation of the CBX2 gene expression was found to inhibit HCC cell viability, migration, and cell cycle progression, while simultaneously promoting apoptosis. CONCLUSIONS: We developed a novel HCC prognostic model utilizing SERGs, indicating that patients with high-risk score not only face a poorer prognosis but also may exhibit a diminished therapeutic response to immune checkpoint inhibitors (ICIs). This model is designed to tailor personalized treatment strategies to the individual needs of each patient, thereby improving the overall clinical outcomes for HCC patients. Furthermore, CBX2 is a promising candidate for therapeutic intervention in HCC.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Medicina de Precisão , Microambiente Tumoral , Humanos , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/terapia , Carcinoma Hepatocelular/mortalidade , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/terapia , Prognóstico , Medicina de Precisão/métodos , Microambiente Tumoral/imunologia , Microambiente Tumoral/genética , Regulação Neoplásica da Expressão Gênica , Biomarcadores Tumorais/genética , Feminino , Masculino , Elementos Facilitadores Genéticos , Linhagem Celular Tumoral , Proliferação de Células
6.
Arch Microbiol ; 206(3): 97, 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38349544

RESUMO

Cordyceps militaris is a well-known medicinal mushroom in Asian countries. This edible fungus has been widely exploited for traditional medicine and functional food production. C. militaris is a heterothallic fungus that requires both the mating-type loci, MAT1-1 and MAT1-2, for fruiting body formation. However, recent studies also indicated two groups of C. militaris, including monokaryotic strains carrying only MAT1-1 in their genomes and heterokaryotic strains harboring both MAT1-1 and MAT1-2. These strain groups are able to produce fruiting bodies under suitable cultivating conditions. In previous work, we showed that monokaryotic strains are more stable than heterokaryotic strains in fruiting body formation through successive culturing generations. In this study, we report a high cordycepin-producing monokaryotic C. militaris strain (HL8) collected in Vietnam. This strain could form normal fruiting bodies with high biological efficiency and contain a cordycepin content of 14.43 mg/g lyophilized fruiting body biomass. The ethanol extraction of the HL8 fruiting bodies resulted in a crude extract with a cordycepin content of 69.15 mg/g. Assays of cytotoxic activity on six human cancer cell lines showed that the extract inhibited the growth of all these cell lines with the IC50 values of 6.41-11.51 µg/mL. Notably, the extract significantly reduced cell proliferation and promoted apoptosis of breast cancer cells. Furthermore, the extract also exhibited strong antifungal activity against Malassezia skin yeasts and the citrus postharvest pathogen Penicillium digitatum. Our work provides a promising monokaryotic C. militaris strain as a bioresource for medicine, cosmetics, and fruit preservation.


Assuntos
Antineoplásicos , Cordyceps , Neoplasias , Penicillium , Humanos , Penicillium/genética , Carpóforos
7.
Physiol Genomics ; 55(3): 147-153, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36847439

RESUMO

Neijiang (NJ) and Yacha (YC) are two indigenous pig breeds in the Sichuan basin of China, displaying higher resistance to diseases, lower lean ratio, and slower growth rate than the commercial Western pig breed Yorkshire (YS). The molecular mechanisms underlying the differences in growth and development between these pig breeds are still unknown. In the present study, five pigs from NJ, YC, and YS breeds were subjected to the whole genome resequencing, and then the differential single-nucleotide polymorphisms (SNPs) were screened using a 10-kb window sliding in 1-kb step using the Fst method. Finally, 48,924, 48,543, and 46,228 nonsynonymous single-nucleotide polymorphism loci (nsSNPs) were identified between NJ and YS, NJ and YC, and YC and YS, which highly or moderately affected 2,490, 800, and 444 genes, respectively. Moreover, three nsSNPs were detected in the genes of acetyl-CoA acetyltransferase 1 (ACAT1) insulin-like growth factor 2 receptor (IGF2R), insulin-like growth factor 2 and mRNA-binding protein 3 (IGF2BP3), which potentially affected the transformation of acetyl-CoA to acetoacetyl-CoA and the normal functions of the insulin signaling pathways. Moreover, serous determinations revealed significantly lower acetyl-CoA content in YC than in YS, supporting that ACAT1 might be a reason explaining the differences in growth and development between YC and YS breeds. Contents of phosphatidylcholine (PC) and phosphatidic acid (PA) significantly differed between the pig breeds, suggesting that glycerophospholipid metabolism might be another reason for the differences between Chinese and Western pig breeds. Overall, these results might contribute basic information to understand the genetic differences determining the phenotypical traits in pigs.


Assuntos
Suínos , Animais , Acetilcoenzima A , Genoma , Polimorfismo de Nucleotídeo Único , Suínos/genética , Suínos/crescimento & desenvolvimento
8.
BMC Cancer ; 23(1): 776, 2023 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-37596527

RESUMO

BACKGROUND: This study targeted at developing a robust, prognostic signature based on super-enhancer-related genes (SERGs) to reveal survival prognosis and immune microenvironment of breast cancer. METHODS: RNA-sequencing data of breast cancer were retrieved from The Cancer Genome Atlas (TCGA), 1069 patients of which were randomly assigned into training or testing set in 1:1 ratio. SERGs were downloaded from Super-Enhancer Database (SEdb). After which, a SERGs signature was established based on the training set, with its prognostic value further validated in the testing set. Subsequently, we identified the potential function enrichment and tumor immune infiltration of the model. Moreover, in vitro experiments were completed to further explore the biological functions of ZIC2 gene (one of the risk genes in the prognostic model) in breast cancer. RESULTS: A risk score system of prognostic value was constructed with 6 SERGs (ZIC2, NFE2, FOXJ1, KLF15, POU3F2 and SPIB) to find patients in high-risk group with significantly worse prognosis in both training and testing sets. In addition, a multivariate regression was established via integrating the 6 genes with age and N stage, indicating well performance by calibration, time-dependent receiver operating characteristic (ROC) analysis and decision curve analysis (DCA). Further analysis demonstrated that tumor-associated pathological processes and pathways were significantly enriched in the high-risk group. In general, the novel SERGs signature could be applied to screen breast cancer with immunosuppressive microenvironment for the risk score was negatively correlated with ESTIMATE score, tumor-infiltration lymphocytes (such as CD4 + and CD8 + T cell), immune checkpoints and chemotactic factors. Furthermore, down-regulation of ZIC2 gene expression inhibited the cell viability, cellular migration and cell cycle of breast cancer cells. CONCLUSIONS: The novel SERGs signature could predict the prognosis of breast cancer; and SERGs might serve as potential therapeutic targets for breast cancer.


Assuntos
Neoplasias da Mama , Humanos , Feminino , Neoplasias da Mama/genética , Sequências Reguladoras de Ácido Nucleico , Prognóstico , Linfócitos T CD8-Positivos , Calibragem , Microambiente Tumoral/genética
9.
Arch Microbiol ; 205(5): 183, 2023 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-37032362

RESUMO

The filamentous fungus Aspergillus niger is widely exploited as an industrial workhorse for producing enzymes and organic acids. So far, different genetic tools, including CRISPR/Cas9 genome editing strategies, have been developed for the engineering of A. niger. However, these tools usually require a suitable method for gene transfer into the fungal genome, like protoplast-mediated transformation (PMT) or Agrobacterium tumefaciens-mediated transformation (ATMT). Compared to PMT, ATMT is considered more advantageous because fungal spores can be used directly for genetic transformation instead of protoplasts. Although ATMT has been applied in many filamentous fungi, it remains less effective in A. niger. In the present study, we deleted the hisB gene and established an ATMT system for A. niger based on the histidine auxotrophic mechanism. Our results revealed that the ATMT system could achieve 300 transformants per 107 fungal spores under optimal transformation conditions. The ATMT efficiency in this work is 5 - 60 times higher than those of the previous ATMT studies in A. niger. The ATMT system was successfully applied to express the DsRed fluorescent protein-encoding gene from the Discosoma coral in A. niger. Furthermore, we showed that the ATMT system was efficient for gene targeting in A. niger. The deletion efficiency of the laeA regulatory gene using hisB as a selectable marker could reach 68 - 85% in A. niger strains. The ATMT system constructed in our work represents a promising genetic tool for heterologous expression and gene targeting in the industrially important fungus A. niger.


Assuntos
Agrobacterium tumefaciens , Aspergillus niger , Aspergillus niger/genética , Transformação Genética , Agrobacterium tumefaciens/genética , Genoma Fúngico
10.
Biotechnol Lett ; 45(5-6): 689-702, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37071381

RESUMO

OBJECTIVES: This work aimed to construct a versatile, effective, and food-grade Agrobacterium tumefaciens-mediated transformation (ATMT) system for recombinant expression in the filamentous fungus Penicillium rubens (also known as Pencillium chrysogenum). RESULTS: In this study, the wild-type P. chrysogenum VTCC 31172 strain was re-classified as P. rubens by a multilocus sequencing analysis. Further, the pyrG gene required for uridine/uracil biosynthesis was successfully deleted in the VTCC 31172 strain by homologous recombination to generate a stable uridine/uracil auxotrophic mutant (ΔpyrG). The growth of the P. rubens ΔpyrG strain could be restored by uridine/uracil supplementation, and a new ATMT system based on the uridine/uracil auxotrophic mechanism was established for this strain. The optimal ATMT efficiency could reach 1750 transformants for 106 spores (equivalent to 0.18%). In addition, supplementation of uridine/uracil at the concentrations of 0.005-0.02% during the co-cultivation process significantly promoted transformation efficiency. Especially, we demonstrated that the pyrG marker and the amyB promoter from the koji mold Aspergillus oryzae were fully functional in P. rubens ΔpyrG. Expression of the DsRed reporter gene under the regulation of the A. oryzae amyB promoter lighted up the mycelium of P. rubens with a robust red signal under fluorescence microscopy. Furthermore, genomic integration of multiple copies of the Aspergillus fumigatus phyA gene under the control of the amyB promoter significantly enhanced phytase activity in P. rubens. CONCLUSIONS: The ATMT system developed in our work provides a safe genetic platform for producing recombinant products in P. rubens without using drug resistance markers.


Assuntos
Penicillium , Penicillium/genética , Penicillium/metabolismo , Agrobacterium tumefaciens/genética , Uracila/metabolismo , Uridina , Transformação Genética
11.
FASEB J ; 35(2): e21170, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33184968

RESUMO

Secretory phospholipase A2 group IB (sPLA2-IB) and M-type phospholipase A2 receptor (PLA2R) are closely associated with proteinuria in idiopathic membranous nephropathy (IMN). Podocytes constitute an important component of glomerular filtration, and high basal autophagy is indispensable for podocyte function. The current study aimed to analyze the relationship between sPLA2-IB and podocyte autophagy in IMN and determine whether sPLA2-IB mediates abnormal autophagy regulation in podocytes. The serum sPLA2-IB level and podocyte autophagy were detected, and clinical data were collected from IMN patients with different proteinuria levels. Then, the effects of sPLA2-IB on autophagy signaling pathways were evaluated in cultured human podocytes treated with sPLA2-IB, rapamycin, p38 inhibition, and PLA2R-siRNA in vitro. We found that IMN patients with nephrotic-range proteinuria have a significantly higher level of sPLA2-IB and fewer autophagosomes than those with non-nephrotic-range proteinuria. In vitro sPLA2-IB-induced insufficient autophagy in podocytes and promoted podocyte injury via activation of the mTOR/ULK1ser757 signaling pathway. Moreover, inhibition of p38 MAPK evidently abrogated sPLA2-IB-induced autophagy and the activation of mTOR/ULK1ser757 . Additionally, PLA2R silencing demonstrated that sPLA2-IB-induced abnormal autophagy was also PLA2R-dependent. In conclusion, the results revealed that sPLA2-IB downregulated autophagy and contributed to podocyte injury via PLA2R though activation of the p38MAPK/mTOR/ULK1ser757 signaling pathway.


Assuntos
Proteína Homóloga à Proteína-1 Relacionada à Autofagia/metabolismo , Autofagia/genética , Glomerulonefrite Membranosa/sangue , Fosfolipases A2 do Grupo IB/sangue , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Sistema de Sinalização das MAP Quinases/genética , Podócitos/metabolismo , Receptores da Fosfolipase A2/sangue , Serina-Treonina Quinases TOR/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Adulto , Idoso , Adesão Celular/genética , Movimento Celular/genética , Células Cultivadas , Feminino , Glomerulonefrite Membranosa/genética , Glomerulonefrite Membranosa/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Proteinúria/sangue , Receptores da Fosfolipase A2/genética , Transfecção
12.
J Org Chem ; 87(21): 14476-14486, 2022 11 04.
Artigo em Inglês | MEDLINE | ID: mdl-36226632

RESUMO

A catalytic selective C-F bond alkylation method for polyfluoroarene with glycinates and derivatives in the presence of a DavePhos-ligated Rh catalyst was developed. This method avoids the preactivation of alkylating reagents and provides an efficient and straightforward route to synthesize a series of polyfluoroaryl amino acids via C(sp3)-H functionalization. This reaction proceeds under mild conditions and exhibits high reactivity and excellent chemoselectivities. Meanwhile, the synthetic potential of this method was demonstrated by gram-scale synthesis, and further transformations proved the application value of the products as well.


Assuntos
Ródio , Ródio/química , Aminoácidos , Catálise
13.
J Org Chem ; 87(1): 231-242, 2022 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-34941259

RESUMO

Amides are important functional synthons that have been widely used in the construction of peptides, natural products, and drugs. The C-N bond cleavage provides the direct method for amide conversion. However, amides, especially secondary amides, tend to be chemically inert due to the resonance of the amide bond. Here, we describe an efficient Pd-catalyzed transamidation and decarbonylation of multiamide structure molecules through C-N bond cleavage with excellent chemoselectivity. The transamidation of secondary amides and the decarbonylation of phthalimide provide meaningful tools for the modification of amino acid derivatives. Moreover, further transformations of azidation and C(sp3)-H monoarylation emphasized the potential utility of this selective C-N bond cleavage method.


Assuntos
Amidas , Paládio , Aminoácidos , Catálise , Peptídeos
14.
Anim Biotechnol ; 33(4): 680-689, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33455520

RESUMO

Gene expression profiles of blood can reflect the physiopathologic status of the immune system. The dynamic microRNA (miRNA) expression profiles of peripheral blood from pigs at different developmental stages, and how differential expression of miRNAs might relate to immune system development, are unknown. In this study, peripheral blood samples taken at five developmental stages were used to construct 15 miRNA libraries (three biological replicates/stage): 0 days (newborn), 30 days (weaning), 60 days (weaned), and 180 and 360 days (puberty). We identified 295 known mature miRNAs. Hierarchical clustering of the miRNA expression profile showed significant differences between individuals at the neonatal and postnatal stages. Functional enrichment analysis revealed that miRNAs differentially expressed between pairwise comparisons of the developmental stages were over-represented in immune-related pathways such as toll-like receptor signaling. The time-course of expression of the over-representated miRNAs exhibited a pattern of steady decline over time, for both the complete miRNA compendium and immune-related miRNAs. We identified six marker miRNAs that were highly negatively correlated with chronologic age and enriched for genes involved in immune-related pathways. This study of a peripheral blood miRNA transcriptome offers insight into immune system development in swine and provides a resource for pig genome annotation.


Assuntos
MicroRNAs , Transcriptoma , Animais , Análise por Conglomerados , Perfilação da Expressão Gênica/veterinária , MicroRNAs/genética , MicroRNAs/metabolismo , Transdução de Sinais , Suínos/genética , Desmame
15.
Angew Chem Int Ed Engl ; 61(26): e202202855, 2022 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-35419921

RESUMO

Transition-metal catalysts exhibit great potential as therapeutic agents to inhibit tumor growth. However, the precise delivery and in situ catalysis are challenging in catalytic medicine. Herein, we report an anti-HER2 affibody-ruthenium catalyst hybrid, named Ru-HER2 for selective and effective killing of cancer cells. Ru-HER2 binds to the HER2 receptor on a tumor cell and in situ catalyzes the activation of gemcitabine prodrug, resulting in enhanced selectivity in suppression of tumor growth and reduction of side effects. Immunoblotting reveals that Ru-HER2 in combination with gemcitabine prodrug can not only induce DNA damage, but also effectively block the HER2 signaling pathway in cancer cells. Therefore, the HER2-targeted chemotherapy exhibits substantially high anticancer activity toward HER2-positive cancer cells in vitro and in vivo. In a word, we report the first affibody-ruthenium catalyst hybrid and reveal its potential for effective HER2-targeted cancer chemotherapy.


Assuntos
Neoplasias , Pró-Fármacos , Rutênio , Catálise , Humanos , Pró-Fármacos/farmacologia , Rutênio/farmacologia
16.
Chemistry ; 27(17): 5453-5460, 2021 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-33220013

RESUMO

Bacterial biofilms are a serious global health concern, often responsible for persistent infections. New strategies to prevent and treat bacterial infections by eradication of the biofilms are urgently needed. A novel ruthenium-based compound is reported in this study that functions as both a boronic acid-decorated photosensitizer (PS) and a light-triggered nitric oxide (NO) releasing agent. The compound can selectively attach to the bacterial membrane and biofilms and it is highly potent at eradicating Pseudomonas aeruginosa biofilms through the simultaneous release of NO and reactive oxygen species (ROS). The compound, which is more effective than clinical antibiotic tobramycin, also has excellent bacterial specificity and shows no significant cytotoxicity to human cells. The results reveal potential applications of this innovative dual-functional photoactivated ruthenium compound to combat bacterial biofilm infections.


Assuntos
Infecções Bacterianas , Fármacos Fotossensibilizantes , Antibacterianos/farmacologia , Infecções Bacterianas/tratamento farmacológico , Biofilmes , Humanos , Óxido Nítrico , Fármacos Fotossensibilizantes/farmacologia , Pseudomonas aeruginosa
17.
BMC Biol ; 18(1): 189, 2020 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-33272269

RESUMO

BACKGROUND: The adenosine-to-inosine (A-to-I) editing in anticodons of tRNAs is critical for wobble base-pairing during translation. This modification is produced via deamination on A34 and catalyzed by the adenosine deaminase acting on tRNA (ADAT) enzyme. Eukaryotic ADATs are heterodimers composed of the catalytic subunit ADAT2 and the structural subunit ADAT3, but their molecular assemblies and catalytic mechanisms are largely unclear. RESULTS: Here, we report a 2.8-Å crystal structure of Saccharomyces cerevisiae ADAT2/3 (ScADAT2/3), revealing its heterodimeric assembly and substrate recognition mechanism. While each subunit clearly contains a domain resembling their prokaryotic homolog TadA, suggesting an evolutionary gene duplication event, they also display accessory domains for additional structural or functional purposes. The N-lobe of ScADAT3 exhibits a positively charged region with a potential role in the recognition and binding of tRNA, supported by our biochemical analysis. Interestingly, ScADAT3 employs its C-terminus to block tRNA's entry into its pseudo-active site and thus inactivates itself for deamination despite the preservation of a zinc-binding site, a mechanism possibly shared only among yeasts. CONCLUSIONS: Combining the structural with biochemical, bioinformatic, and in vivo functional studies, we propose a stepwise model for the pathway of deamination by ADAT2/3. Our work provides insight into the molecular mechanism of the A-to-I editing by the eukaryotic ADAT heterodimer, especially the role of ADAT3 in catalysis.


Assuntos
Anticódon/genética , Saccharomyces cerevisiae/genética , Filogenia , Multimerização Proteica , Estrutura Secundária de Proteína , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/enzimologia
18.
J Biol Chem ; 294(20): 7990-8000, 2019 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-30936204

RESUMO

Knowledge of the molecular mechanisms of specific bacterial virulence factors can significantly contribute to antibacterial drug discovery. Helicobacter pylori is a Gram-negative microaerophilic bacterium that infects almost half of the world's population, leading to gastric disorders and even gastric cancer. H. pylori expresses a series of virulence factors in the host, among which high-temperature requirement A (HpHtrA) is a newly identified serine protease secreted by H. pylori. HpHtrA cleaves the extracellular domain of the epithelial cell surface adhesion protein E-cadherin and disrupts gastric epithelial cell junctions, allowing H. pylori to access the intercellular space. Here we report the first crystal structure of HpHtrA at 3.0 Å resolution. The structure revealed a new type of HtrA protease trimer stabilized by unique N-terminal domain swapping distinct from other known HtrA homologs. We further observed that truncation of the N terminus completely abrogates HpHtrA trimer formation as well as protease activity. In the presence of unfolded substrate, HpHtrA assembled into cage-like 12-mers or 24-mers. Combining crystallographic, biochemical, and mutagenic data, we propose a mechanistic model of how HpHtrA recognizes and cleaves the well-folded E-cadherin substrate. Our study provides a fundamental basis for the development of anti-H. pylori agents by using a previously uncharacterized HtrA protease as a target.


Assuntos
Proteínas de Bactérias/química , Helicobacter pylori/enzimologia , Modelos Biológicos , Serina Endopeptidases/química , Fatores de Virulência/química , Antígenos CD/química , Antígenos CD/genética , Antígenos CD/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Caderinas/química , Caderinas/genética , Caderinas/metabolismo , Cristalografia por Raios X , Helicobacter pylori/genética , Helicobacter pylori/patogenicidade , Humanos , Domínios Proteicos , Serina Endopeptidases/genética , Serina Endopeptidases/metabolismo , Especificidade por Substrato , Fatores de Virulência/genética , Fatores de Virulência/metabolismo
19.
Exp Cell Res ; 385(1): 111597, 2019 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-31525340

RESUMO

Cancer stem cells (CSCs) are a subpopulation of chemoresistant cells that play a critical role in disease recurrence following chemotherapy. It has been reported that microRNA-133b (miR-133b) acts as a tumor suppressor in colorectal cancer (CRC). However, whether miR-133b is associated with CRC stemness and chemoresistance is not clear. In this study, we report that miR-133b is downregulated in colorectal spheroids, which are enriched with CSCs and display stem cell-like characteristics, including upreulation of CSCs surface markers and elevated chemoresistance. Additionally, miR-133b overexpression reduces CRC stemness and overrides chemoresistance to 5-Fluorouracil (5-FU) and oxaliplatin (OXP), indicating a negative role of miR-133b in regulating CRC stemness and chemoresistance. Moreover, miR-133b directly targets and suppresses the expression of disruptor of telomeric silencing 1-like (DOT1L), an exclusive H3K79 methyltransferase. Furthermore, miR-133b overexpression suppresses DOT1L-mediated H3K79me2 modification of stem cell genes, which is consistent with their downregulated transcription. More importantly, DOT1L restoration abrogates the suppressive effects of miR-133b on CRC stemness and chemoresistance, hence demonstrating that miR-133b regulates CRC stemness and chemoresistance through targeting DOT1L. Overall, these results imply that miR-133b might represent a novel therapeutic target in interfering CRC stemness and chemoresistance.


Assuntos
Neoplasias Colorretais/genética , Resistencia a Medicamentos Antineoplásicos/genética , Histona-Lisina N-Metiltransferase/genética , MicroRNAs/genética , Células-Tronco Neoplásicas/patologia , Linhagem Celular , Linhagem Celular Tumoral , Proliferação de Células/genética , Neoplasias Colorretais/tratamento farmacológico , Regulação para Baixo/genética , Fluoruracila/farmacologia , Regulação Neoplásica da Expressão Gênica/genética , Genes Supressores de Tumor/fisiologia , Células HCT116 , Células HEK293 , Células HT29 , Humanos , Oxaliplatina/farmacologia , Transcrição Gênica/genética , Regulação para Cima/genética
20.
Asian-Australas J Anim Sci ; 33(5): 836-847, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31480157

RESUMO

OBJECTIVE: We investigated the temporal expression profiles of long noncoding RNA (lncRNA) and mRNA in the peripheral blood of pigs during development and identified the lncRNAs that are related to the blood-based immune system. METHODS: Peripheral blood samples were obtained from the pigs at 0, 7, 28, and 180 days and 2 years of age. RNA sequencing was performed to survey the lncRNA and mRNA transcriptomes in the samples. Short time-series expression miner (STEM) was used to show temporal expression patterns in the mRNAs and lncRNAs. Gene ontology and Kyoto encyclopedia of genes and genomes analyses were performed to assess the genes' biological relevance. To predict the functions of the identified lncRNAs, we extracted mRNAs that were nearby loci and highly correlated with the lncRNAs. RESULTS: In total of 5,946 lncRNA and 12,354 mRNA transcripts were identified among the samples. STEM showed that most lncRNAs and mRNAs had similar temporal expression patterns during development, indicating the expressional correlation and functional relatedness between them. The five stages were divided into two classes: the suckling period and the late developmental stage. Most genes were expressed at low level during the suckling period, but at higher level during the late stages. Expression of several T-cell-related genes increased continuously during the suckling period, indicating that these genes are crucial for establishing the adaptive immune system in piglets at this stage. Notably, lncRNA TCONS-00086451may promote blood-based immune system development by upregulating nuclear factor of activated T-cells cytoplasmic 2 expression. CONCLUSION: This study provides a catalog of porcine peripheral blood-related lncRNAs and mRNAs and reveals the characteristics and temporal expression profiles of these lncRNAs and mRNAs during peripheral blood development from the newborn to adult stages in pigs.

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