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1.
Trends Biochem Sci ; 48(3): 288-302, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36280495

RESUMO

Antisynthetase syndrome (ASSD) is an autoimmune disease characterized by circulating autoantibodies against one of eight aminoacyl-tRNA synthetases (aaRSs). Although these autoantibodies are believed to play critical roles in ASSD pathogenesis, the nature of their roles remains unclear. Here we describe ASSD pathogenesis and discuss ASSD-linked aaRSs - from the WHEP domain that may impart immunogenicity to the role of tRNA in eliciting the innate immune response and the secretion of aaRSs from cells. Through these explorations, we propose that ASSD pathogenesis involves the tissue-specific secretion of aaRSs and that extracellular tRNAs or tRNA fragments and their ability to engage Toll-like receptor signaling may be important disease factors.


Assuntos
Aminoacil-tRNA Sintetases , Miosite , Humanos , Aminoacil-tRNA Sintetases/genética , RNA de Transferência/genética , Autoanticorpos
2.
Gastroenterology ; 167(2): 343-356, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38342194

RESUMO

BACKGROUND & AIMS: Apoptosis generates plenty of membrane-bound nanovesicles, the apoptotic vesicles (apoVs), which show promise for biomedical applications. The liver serves as a significant organ for apoptotic material removal. Whether and how the liver metabolizes apoptotic vesicular products and contributes to liver health and disease is unrecognized. METHODS: apoVs were labeled and traced after intravenous infusion. Apoptosis-deficient mice by Fas mutant (Fasmut) and Caspase-3 knockout (Casp3-/-) were used with apoV replenishment to evaluate the physiological apoV function. Combinations of morphologic, biochemical, cellular, and molecular assays were applied to assess the liver while hepatocyte analysis was performed. Partial hepatectomy and acetaminophen liver failure models were established to investigate liver regeneration and disease recovery. RESULTS: We discovered that the liver is a major metabolic organ of circulatory apoVs, in which apoVs undergo endocytosis by hepatocytes via a sugar recognition system. Moreover, apoVs play an indispensable role to counteract hepatocellular injury and liver impairment in apoptosis-deficient mice upon replenishment. Surprisingly, apoVs form a chimeric organelle complex with the hepatocyte Golgi apparatus through the soluble N-ethylmaleimide-sensitive factor attachment protein receptor machinery, which preserves Golgi integrity, promotes microtubule acetylation by regulating α-tubulin N-acetyltransferase 1, and consequently facilitates hepatocyte cytokinesis for liver recovery. The assembly of the apoV-Golgi complex is further revealed to contribute to liver homeostasis, regeneration, and protection against acute liver failure. CONCLUSIONS: These findings establish a previously unrecognized functional and mechanistic framework that apoptosis through vesicular metabolism safeguards liver homeostasis and regeneration, which holds promise for hepatic disease therapeutics.


Assuntos
Apoptose , Hepatócitos , Homeostase , Regeneração Hepática , Fígado , Camundongos Knockout , Animais , Hepatócitos/metabolismo , Hepatócitos/patologia , Fígado/metabolismo , Fígado/patologia , Caspase 3/metabolismo , Camundongos , Hepatectomia , Modelos Animais de Doenças , Receptor fas/metabolismo , Receptor fas/genética , Complexo de Golgi/metabolismo , Endocitose , Doença Hepática Induzida por Substâncias e Drogas/patologia , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Doença Hepática Induzida por Substâncias e Drogas/genética , Camundongos Endogâmicos C57BL , Acetaminofen , Masculino
3.
Nucleic Acids Res ; 51(19): 10768-10781, 2023 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-37739431

RESUMO

Translational readthrough of UGA stop codons by selenocysteine-specific tRNA (tRNASec) enables the synthesis of selenoproteins. Seryl-tRNA synthetase (SerRS) charges tRNASec with serine, which is modified into selenocysteine and delivered to the ribosome by a designated elongation factor (eEFSec in eukaryotes). Here we found that components of the human selenocysteine incorporation machinery (SerRS, tRNASec, and eEFSec) also increased translational readthrough of non-selenocysteine genes, including VEGFA, to create C-terminally extended isoforms. SerRS recognizes target mRNAs through a stem-loop structure that resembles the variable loop of its cognate tRNAs. This function of SerRS depends on both its enzymatic activity and a vertebrate-specific domain. Through eCLIP-seq, we identified additional SerRS-interacting mRNAs as potential readthrough genes. Moreover, SerRS overexpression was sufficient to reverse premature termination caused by a pathogenic nonsense mutation. Our findings expand the repertoire of selenoprotein biosynthesis machinery and suggest an avenue for therapeutic targeting of nonsense mutations using endogenous factors.


Assuntos
Biossíntese de Proteínas , Serina-tRNA Ligase , Humanos , Códon sem Sentido , Códon de Terminação , RNA Mensageiro/metabolismo , Selenocisteína/genética , Selenocisteína/metabolismo , Selenoproteínas/genética , Serina-tRNA Ligase/genética
4.
Nucleic Acids Res ; 51(18): 10001-10010, 2023 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-37638745

RESUMO

Through their aminoacylation reactions, aminoacyl tRNA-synthetases (aaRS) establish the rules of the genetic code throughout all of nature. During their long evolution in eukaryotes, additional domains and splice variants were added to what is commonly a homodimeric or monomeric structure. These changes confer orthogonal functions in cellular activities that have recently been uncovered. An unusual exception to the familiar architecture of aaRSs is the heterodimeric metazoan mitochondrial SerRS. In contrast to domain additions or alternative splicing, here we show that heterodimeric metazoan mitochondrial SerRS arose from its homodimeric ancestor not by domain additions, but rather by collapse of an entire domain (in one subunit) and an active site ablation (in the other). The collapse/ablation retains aminoacylation activity while creating a new surface, which is necessary for its orthogonal function. The results highlight a new paradigm for repurposing a member of the ancient tRNA synthetase family.


Assuntos
Serina-tRNA Ligase , Animais , Aminoacil-tRNA Sintetases/metabolismo , Domínio Catalítico , Serina-tRNA Ligase/química , Serina-tRNA Ligase/metabolismo
5.
Proc Natl Acad Sci U S A ; 119(48): e2212659119, 2022 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-36409883

RESUMO

Platelets play a role not only in hemostasis and thrombosis, but also in inflammation and innate immunity. We previously reported that an activated form of tyrosyl-tRNA synthetase (YRSACT) has an extratranslational activity that enhances megakaryopoiesis and platelet production in mice. Here, we report that YRSACT mimics inflammatory stress inducing a unique megakaryocyte (MK) population with stem cell (Sca1) and myeloid (F4/80) markers through a mechanism dependent on Toll-like receptor (TLR) activation and type I interferon (IFN-I) signaling. This mimicry of inflammatory stress by YRSACT was studied in mice infected by lymphocytic choriomeningitis virus (LCMV). Using Sca1/EGFP transgenic mice, we demonstrated that IFN-I induced by YRSACT or LCMV infection suppressed normal hematopoiesis while activating an alternative pathway of thrombopoiesis. Platelets of inflammatory origin (Sca1/EGFP+) were a relevant proportion of those circulating during recovery from thrombocytopenia. Analysis of these "inflammatory" MKs and platelets suggested their origin in myeloid/MK-biased hematopoietic stem cells (HSCs) that bypassed the classical MK-erythroid progenitor (MEP) pathway to replenish platelets and promote recovery from thrombocytopenia. Notably, inflammatory platelets displayed enhanced agonist-induced activation and procoagulant activities. Moreover, myeloid/MK-biased progenitors and MKs were mobilized from the bone marrow, as evidenced by their presence in the lung microvasculature within fibrin-containing microthrombi. Our results define the function of YRSACT in platelet generation and contribute to elucidate platelet alterations in number and function during viral infection.


Assuntos
Ataxias Espinocerebelares , Trombocitopenia , Trombose , Tirosina-tRNA Ligase , Viroses , Camundongos , Animais , Trombopoese , Camundongos Transgênicos
6.
J Cell Mol Med ; 28(13): e18530, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38961673

RESUMO

Tumour morphology (tumour burden score (TBS)) and liver function (albumin-to-alkaline phosphatase ratio (AAPR)) have been shown to correlate with outcomes in intrahepatic cholangiocarcinoma (ICC). This study aimed to evaluate the combined predictive effect of TBS and AAPR on survival outcomes in ICC patients. We conducted a retrospective analysis using a multicentre database of ICC patients who underwent curative surgery from 2011 to 2018. The Kaplan-Meier method was employed to examine the relationship between a new index (combining TBS and AAPR) and long-term outcomes. The predictive efficacy of this index was compared to other conventional indicators. A total of 560 patients were included in the study. Based on TBS and AAPR stratification, patients were classified into three groups. Kaplan-Meier curves demonstrated that 124 patients with low TBS and high AAPR had the best overall survival (OS) and recurrence-free survival (RFS), while 170 patients with high TBS and low AAPR had the worst outcomes (log-rank p < 0.001). Multivariate analyses identified the combined index as an independent predictor of OS and RFS. Furthermore, the index showed superior accuracy in predicting OS and RFS compared to other conventional indicators. Collectively, this study demonstrated that the combination of liver function and tumour morphology provides a synergistic effect in evaluating the prognosis of ICC patients. The novel index combining TBS and AAPR effectively stratified postoperative survival outcomes in ICC patients undergoing curative resection.


Assuntos
Fosfatase Alcalina , Neoplasias dos Ductos Biliares , Colangiocarcinoma , Carga Tumoral , Humanos , Colangiocarcinoma/patologia , Colangiocarcinoma/cirurgia , Colangiocarcinoma/sangue , Colangiocarcinoma/mortalidade , Feminino , Masculino , Fosfatase Alcalina/sangue , Pessoa de Meia-Idade , Prognóstico , Neoplasias dos Ductos Biliares/patologia , Neoplasias dos Ductos Biliares/cirurgia , Neoplasias dos Ductos Biliares/mortalidade , Neoplasias dos Ductos Biliares/sangue , Idoso , Estudos Retrospectivos , Estimativa de Kaplan-Meier , Biomarcadores Tumorais/sangue
7.
J Am Chem Soc ; 146(13): 9356-9364, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38502531

RESUMO

Pharmaceuticals and biologically active natural products usually contain multiple stereocenters. The development of catalytic asymmetric reactions for the direct construction of complex motifs containing three nonadjacent stereocenters is a particularly important and formidable challenge. In this paper, we report an unprecedented method for the direct asymmetric construction of complex chiral amines with 1,3,5- or 1,3,4-stereocenters from readily available achiral and racemic starting materials. The reaction was made possible by the development of highly efficient chiral ammonium catalysts that serve three distinct functions: promoting efficient kinetic resolution by chiral recognition of racemic electrophiles, promoting asymmetric C-C bond forming reactions by recognizing enantiotropic faces of achiral nucleophiles, and mediating a highly stereoselective protonation of carbanions. Using these trifunctional catalysts, the reaction of imines and tulipane derivatives proceeded in a highly regio-, chemo-, and stereoselective manner to produce synthetically useful yields of complex chiral amines. We believe that trifunctional catalysis can be applied in a variety of asymmetric transformations for the streamlined asymmetric synthesis of complex chiral molecules with multiple stereocenters.

8.
Neurobiol Dis ; 195: 106501, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38583640

RESUMO

Charcot-Marie-Tooth disease (CMT) is a genetic peripheral neuropathy caused by mutations in many functionally diverse genes. The aminoacyl-tRNA synthetase (ARS) enzymes, which transfer amino acids to partner tRNAs for protein synthesis, represent the largest protein family genetically linked to CMT aetiology, suggesting pathomechanistic commonalities. Dominant intermediate CMT type C (DI-CMTC) is caused by YARS1 mutations driving a toxic gain-of-function in the encoded tyrosyl-tRNA synthetase (TyrRS), which is mediated by exposure of consensus neomorphic surfaces through conformational changes of the mutant protein. In this study, we first showed that human DI-CMTC-causing TyrRSE196K mis-interacts with the extracellular domain of the BDNF receptor TrkB, an aberrant association we have previously characterised for several mutant glycyl-tRNA synthetases linked to CMT type 2D (CMT2D). We then performed temporal neuromuscular assessments of YarsE196K mice modelling DI-CMT. We determined that YarsE196K homozygotes display a selective, age-dependent impairment in in vivo axonal transport of neurotrophin-containing signalling endosomes, phenocopying CMT2D mice. This impairment is replicated by injection of recombinant TyrRSE196K, but not TyrRSWT, into muscles of wild-type mice. Augmenting BDNF in DI-CMTC muscles, through injection of recombinant protein or muscle-specific gene therapy, resulted in complete axonal transport correction. Therefore, this work identifies a non-cell autonomous pathomechanism common to ARS-related neuropathies, and highlights the potential of boosting BDNF levels in muscles as a therapeutic strategy.


Assuntos
Transporte Axonal , Fator Neurotrófico Derivado do Encéfalo , Doença de Charcot-Marie-Tooth , Modelos Animais de Doenças , Animais , Doença de Charcot-Marie-Tooth/genética , Doença de Charcot-Marie-Tooth/metabolismo , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Fator Neurotrófico Derivado do Encéfalo/genética , Camundongos , Tirosina-tRNA Ligase/genética , Tirosina-tRNA Ligase/metabolismo , Humanos , Camundongos Transgênicos , Músculo Esquelético/metabolismo , Receptor trkB/metabolismo , Receptor trkB/genética , Mutação
9.
Nature ; 564(7736): E37, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30459470

RESUMO

In Fig. 1b of this Article, a U was inadvertently inserted after G15 in the D loop. The original Article has not been corrected.

10.
Proc Natl Acad Sci U S A ; 118(13)2021 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-33753480

RESUMO

Through dominant mutations, aminoacyl-tRNA synthetases constitute the largest protein family linked to Charcot-Marie-Tooth disease (CMT). An example is CMT subtype 2N (CMT2N), caused by individual mutations spread out in AlaRS, including three in the aminoacylation domain, thereby suggesting a role for a tRNA-charging defect. However, here we found that two are aminoacylation defective but that the most widely distributed R329H is normal as a purified protein in vitro and in unfractionated patient cell samples. Remarkably, in contrast to wild-type (WT) AlaRS, all three mutant proteins gained the ability to interact with neuropilin 1 (Nrp1), the receptor previously linked to CMT pathogenesis in GlyRS. The aberrant AlaRS-Nrp1 interaction is further confirmed in patient samples carrying the R329H mutation. However, CMT2N mutations outside the aminoacylation domain do not induce the Nrp1 interaction. Detailed biochemical and biophysical investigations, including X-ray crystallography, small-angle X-ray scattering, hydrogen-deuterium exchange (HDX), switchSENSE hydrodynamic diameter determinations, and protease digestions reveal a mutation-induced structural loosening of the aminoacylation domain that correlates with the Nrp1 interaction. The b1b2 domains of Nrp1 are responsible for the interaction with R329H AlaRS. The results suggest Nrp1 is more broadly associated with CMT-associated members of the tRNA synthetase family. Moreover, we revealed a distinct structural loosening effect induced by a mutation in the editing domain and a lack of conformational impact with C-Ala domain mutations, indicating mutations in the same protein may cause neuropathy through different mechanisms. Our results show that, as with other CMT-associated tRNA synthetases, aminoacylation per se is not relevant to the pathology.


Assuntos
Alanina-tRNA Ligase/metabolismo , Doença de Charcot-Marie-Tooth/genética , Neuropilina-1/metabolismo , Alanina-tRNA Ligase/química , Alanina-tRNA Ligase/genética , Aminoacilação/genética , Células Cultivadas , Doença de Charcot-Marie-Tooth/sangue , Cristalografia por Raios X , Medição da Troca de Deutério , Humanos , Linfócitos , Mutação , Neuropilina-1/genética , Cultura Primária de Células , Ligação Proteica/genética , Domínios Proteicos/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/ultraestrutura , Espalhamento a Baixo Ângulo
11.
Int Wound J ; 21(4): e14795, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38572781

RESUMO

This study investigates the effects of comprehensive nursing interventions on wound pain in patients undergoing catheter insertion for peritoneal dialysis. Sixty patients who underwent catheter insertion for peritoneal dialysis from January 2021 to January 2023 at our hospital were selected as subjects and randomly divided into an experimental group and a control group using a random number table method. The control group received routine nursing care, while the experimental group was subjected to comprehensive nursing interventions. The study compared the impact of nursing measures on visual analogue scale (VAS), self-rating anxiety scale (SAS), self-rating depression scale (SDS) and nursing satisfaction between the two groups. The analysis revealed that on the third, fifth and seventh days post-intervention, the experimental group's wound VAS scores were significantly lower than those of the control group (p < 0.001). Furthermore, levels of anxiety and depression were markedly lower in the experimental group compared with the control group (p < 0.001). In addition, the nursing satisfaction rate was significantly higher in the experimental group than in the control group (96.67% vs. 73.33%, p = 0.011). This study indicates that the application of comprehensive nursing interventions in patients undergoing catheter insertion for peritoneal dialysis is highly effective. It can alleviate wound pain and negative emotions to a certain extent, while also achieving high patient satisfaction, thus demonstrating significant clinical value.


Assuntos
Dor , Diálise Peritoneal , Humanos , Ansiedade/etiologia , Ansiedade/terapia , Transtornos de Ansiedade , Catéteres
12.
J Am Chem Soc ; 145(8): 4400-4407, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36800284

RESUMO

Catalytic asymmetric cross-coupling of imines constitutes a particularly desirable method for the synthesis of chiral vicinal diamines directly from readily available achiral precursors. The potential of this method lies in the possibility of utilizing a variety of imines as reacting partners. However, the realization of highly stereoselective cross-coupling of two different imines proved to be a formidable challenge. Herein we report an unprecedented catalytic asymmetric cross-coupling reaction that tolerates a variety of ketimines and aldimines as nucleophiles and electrophiles, respectively. The realization of this reaction resulted from the development of a new chiral ammonium catalyst, which was guided by insights from studies of catalyst-substrate interactions. With a 0.5 mol % loading of an organocatalyst, this reaction proceeded in a highly diastereo- and enantioselective manner to afford a diverse range of chiral vicinal diamines as nearly single stereoisomers. This catalytic reaction establishes a new approach for the asymmetric synthesis of chiral vicinal diamines.

13.
J Neuroinflammation ; 20(1): 247, 2023 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-37880726

RESUMO

BACKGROUND: The astrocytes in the central nervous system (CNS) exhibit morphological and functional diversity in brain region-specific pattern. Functional alterations of reactive astrocytes are commonly present in human temporal lobe epilepsy (TLE) cases, meanwhile the neuroinflammation mediated by reactive astrocytes may advance the development of hippocampal epilepsy in animal models. Nuclear factor I-A (NFIA) may regulate astrocyte diversity in the adult brain. However, whether NFIA endows the astrocytes with regional specificity to be involved in epileptogenesis remains elusive. METHODS: Here, we utilize an interference RNA targeting NFIA to explore the characteristics of NFIA expression and its role in astrocyte reactivity in a 4-aminopyridine (4-AP)-induced seizure model in vivo and in vitro. Combined with the employment of a HA-tagged plasmid overexpressing NFIA, we further investigate the precise mechanisms how NIFA facilitates epileptogenesis. RESULTS: 4-AP-induced NFIA upregulation in hippocampal region is astrocyte-specific, and primarily promotes detrimental actions of reactive astrocyte. In line with this phenomenon, both NFIA and vanilloid transient receptor potential 4 (TRPV4) are upregulated in hippocampal astrocytes in human samples from the TLE surgical patients and mouse samples with intraperitoneal 4-AP. NFIA directly regulates mouse astrocytic TRPV4 expression while the quantity and the functional activity of TRPV4 are required for 4-AP-induced astrocyte reactivity and release of proinflammatory cytokines in the charge of NFIA upregulation. NFIA deficiency efficiently inhibits 4-AP-induced TRPV4 upregulation, weakens astrocytic calcium activity and specific astrocyte reactivity, thereby mitigating aberrant neuronal discharges and neuronal damage, and suppressing epileptic seizure. CONCLUSIONS: Our results uncover the critical role of NFIA in astrocyte reactivity and illustrate how epileptogenic brain injury initiates cell-specific signaling pathway to dictate the astrocyte responses.


Assuntos
Epilepsia do Lobo Temporal , Epilepsia , Fatores de Transcrição NFI , Canais de Cátion TRPV , Animais , Humanos , Camundongos , 4-Aminopiridina/efeitos adversos , Astrócitos/metabolismo , Encéfalo/metabolismo , Sistema Nervoso Central/metabolismo , Epilepsia/metabolismo , Epilepsia do Lobo Temporal/induzido quimicamente , Epilepsia do Lobo Temporal/metabolismo , Fatores de Transcrição NFI/genética , Fatores de Transcrição NFI/metabolismo , Canais de Cátion TRPV/metabolismo , Regulação para Cima
14.
Gastrointest Endosc ; 97(4): 664-672.e4, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36509114

RESUMO

BACKGROUND AND AIMS: Although narrow-band imaging (NBI) is a useful modality for detecting and delineating esophageal squamous cell carcinoma (ESCC), there is a risk of incorrectly determining the margins of some lesions even with NBI. This study aimed to develop an artificial intelligence (AI) system for detecting superficial ESCC and precancerous lesions and delineating the extent of lesions under NBI. METHODS: Nonmagnified NBI images from 4 hospitals were collected and annotated. Internal and external image test datasets were used to evaluate the detection and delineation performance of the system. The delineation performance of the system was compared with that of endoscopists. Furthermore, the system was directly integrated into the endoscopy equipment, and its real-time diagnostic capability was prospectively estimated. RESULTS: The system was trained and tested using 10,047 still images and 140 videos from 1112 patients and 1183 lesions. In the image testing, the accuracy of the system in detecting lesions in internal and external tests was 92.4% and 89.9%, respectively. The accuracy of the system in delineating extents in internal and external tests was 88.9% and 87.0%, respectively. The delineation performance of the system was superior to that of junior endoscopists and similar to that of senior endoscopists. In the prospective clinical evaluation, the system exhibited satisfactory performance, with an accuracy of 91.4% in detecting lesions and an accuracy of 85.9% in delineating extents. CONCLUSIONS: The proposed AI system could accurately detect superficial ESCC and precancerous lesions and delineate the extent of lesions under NBI.


Assuntos
Carcinoma de Células Escamosas , Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , Lesões Pré-Cancerosas , Humanos , Carcinoma de Células Escamosas do Esôfago/diagnóstico por imagem , Carcinoma de Células Escamosas do Esôfago/patologia , Neoplasias Esofágicas/patologia , Carcinoma de Células Escamosas/patologia , Estudos Prospectivos , Inteligência Artificial , Lesões Pré-Cancerosas/diagnóstico por imagem , Imagem de Banda Estreita , Endoscopia Gastrointestinal
15.
PLoS Biol ; 18(12): e3000991, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33351793

RESUMO

Hypoxia-induced angiogenesis maintains tissue oxygen supply and protects against ischemia but also enhances tumor progression and malignancy. This is mediated through activation of transcription factors like hypoxia-inducible factor 1 (HIF-1) and c-Myc, yet the impact of hypoxia on negative regulators of angiogenesis is unknown. During vascular development, seryl-tRNA synthetase (SerRS) regulates angiogenesis through a novel mechanism by counteracting c-Myc and transcriptionally repressing vascular endothelial growth factor A (VEGFA) expression. Here, we reveal that the transcriptional repressor role of SerRS is inactivated under hypoxia through phosphorylation by ataxia telangiectasia mutated (ATM) and ataxia telangiectasia mutated and RAD3-related (ATR) at Ser101 and Ser241 to attenuate its DNA binding capacity. In zebrafish, SerRSS101D/S241D, a phosphorylation-mimicry mutant, cannot suppress VEGFA expression to support normal vascular development. Moreover, expression of SerRSS101A/S241A, a phosphorylation-deficient and constitutively active mutant, prevents hypoxia-induced binding of c-Myc and HIF-1 to the VEGFA promoter, and activation of VEGFA expression. Consistently, SerRSS101A/S241A strongly inhibits normal and tumor-derived angiogenesis in mice. Therefore, we reveal a key step regulating hypoxic angiogenesis and highlight the importance of nuclear SerRS in post-developmental angiogenesis regulation in addition to vascular development. The role of nuclear SerRS in inhibiting both c-Myc and HIF-1 may provide therapeutic opportunities to correct dysregulation of angiogenesis in pathological settings.


Assuntos
Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Neovascularização Patológica/genética , Serina-tRNA Ligase/metabolismo , Indutores da Angiogênese , Animais , Animais Geneticamente Modificados , Ataxia Telangiectasia/genética , Proteínas Mutadas de Ataxia Telangiectasia/genética , Proteínas Mutadas de Ataxia Telangiectasia/fisiologia , Linhagem Celular , Feminino , Células HEK293 , Humanos , Hipóxia/metabolismo , Hipóxia/fisiopatologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Camundongos , Camundongos Nus , Fosforilação , Serina-tRNA Ligase/fisiologia , Fatores de Transcrição/metabolismo , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto/métodos , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/metabolismo
16.
Nanotechnology ; 35(7)2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37976546

RESUMO

In this study, we conducted molecular dynamic simulations to investigate the thermal expansion behavior of Janus MoSSe nanotubes. We focused on understanding how the intrinsic strain in these nanotubes affects their thermal expansion coefficient (TEC). Interestingly, we found that Janus MoSSe nanotubes with sulfur (S) on the outer surface (MoSeS) exhibit a different intrinsic strain compared to those with selenium (Se) on the outer surface (MoSSe). In light of this observation, we explored the influence of this intrinsic strain on the TEC of the nanotubes. Our results revealed distinct trends for the TEC along the radial direction (TEC-r) and the axial direction (TEC-lx) of the MoSSe and MoSeS nanotubes. The TEC-rof MoSeS nanotubes was found to be significantly greater than that of MoSSe nanotubes. Moreover, the TEC-lxof MoSeS nanotubes was smaller than that of MoSSe nanotubes. Further analysis showed that the TEC-rof MoSeS nanotubes decreased by up to 37% as the radius increased, while that of MoSSe nanotubes exhibited a slight increase with increasing radius. On the other hand, the TEC-lxof MoSeS nanotubes increased by as much as 45% with increasing radius, whereas that of MoSSe nanotubes decreased gradually. These opposite tendencies of the TECs with respect to the radius were attributed to the presence of intrinsic strain within the nanotubes. The intrinsic strain was found to play a crucial role in inducing thermally induced bending and elliptization of the nanotubes' cross-section. These effects are considered key mechanisms through which intrinsic strain influences the TEC. Overall, our study provides valuable insights into the thermal stability of Janus nanotubes. By understanding the relationship between intrinsic strain and the thermal expansion behavior of nanotubes, we contribute to the broader understanding of these materials and their potential applications.

17.
Environ Sci Technol ; 57(46): 18317-18328, 2023 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-37186812

RESUMO

Machine learning (ML) models were developed for understanding the root uptake of per- and polyfluoroalkyl substances (PFASs) under complex PFAS-crop-soil interactions. Three hundred root concentration factor (RCF) data points and 26 features associated with PFAS structures, crop properties, soil properties, and cultivation conditions were used for the model development. The optimal ML model, obtained by stratified sampling, Bayesian optimization, and 5-fold cross-validation, was explained by permutation feature importance, individual conditional expectation plot, and 3D interaction plot. The results showed that soil organic carbon contents, pH, chemical logP, soil PFAS concentration, root protein contents, and exposure time greatly affected the root uptake of PFASs with 0.43, 0.25, 0.10, 0.05, 0.05, and 0.05 of relative importance, respectively. Furthermore, these factors presented the key threshold ranges in favor of the PFAS uptake. Carbon-chain length was identified as the critical molecular structure affecting root uptake of PFASs with 0.12 of relative importance, based on the extended connectivity fingerprints. A user-friendly model was established with symbolic regression for accurately predicting RCF values of the PFASs (including branched PFAS isomerides). The present study provides a novel approach for profound insight into the uptake of PFASs by crops under complex PFAS-crop-soil interactions, aiming to ensure food safety and human health.


Assuntos
Fluorocarbonos , Poluentes Químicos da Água , Humanos , Solo/química , Carbono , Teorema de Bayes , Fluorocarbonos/análise , Aprendizado de Máquina , Poluentes Químicos da Água/análise
18.
Environ Sci Technol ; 57(42): 16053-16064, 2023 10 24.
Artigo em Inglês | MEDLINE | ID: mdl-37824517

RESUMO

Rhizosphere microbiota are an important factor impacting plant uptake of pollutants. However, little is known about how microbial nitrogen (N) transformation in the rhizosphere affects the uptake and accumulation of antibiotics in plants. Here, we determined recruitment of N transformation functional bacteria upon ciprofloxacin (CIP) exposure, by comparing differences in assembly processes of both rhizospheric bacterial communities and N transformation between two choysum (Brassica parachinensis) varieties differing in CIP accumulation. The low accumulation variety (LAV) of CIP recruited more host bacteria (e.g., Nitrospiria and Nitrolancea) carrying nitrification genes (mainly nxrA) but fewer host bacteria carrying denitrification genes, especially narG, relative to the high accumulation variety (HAV) of CIP. The nxrA and narG abundance in the LAV rhizosphere were, respectively, 1.6-7.8 fold higher and 1.4-3.4 fold lower than those in the HAV rhizosphere. Considering that nitrate can decrease CIP uptake into choysum through competing for the proton motive force and energy, such specific bacteria recruitment in LAV favored the production and utilization of nitrate in its rhizosphere, thus limiting its CIP accumulation with 1.6-2.4 fold lower than the HAV. The findings give insight into the mechanism underlying low pollutant accumulation, filling the knowledge gap regarding the profound effects of rhizosphere microflora and N transformation processes on antibiotic accumulation in crops.


Assuntos
Brassica , Ciprofloxacina , Rizosfera , Nitratos , Nitrogênio/análise , Antibacterianos , Bactérias/genética , Plantas , Solo , Microbiologia do Solo
19.
Acta Pharmacol Sin ; 44(4): 877-887, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36207403

RESUMO

Neuroblastoma is the most common and deadliest tumor in infancy. WDR5 (WD Repeat Domain 5), a critical factor supporting an N-myc transcriptional complex via its WBM site and interacting with chromosome via its WIN site, promotes the progression of neuroblastoma, thus making it a potential anti-neuroblastoma drug target. So far, a few WIN site inhibitors have been reported, and the WBM site disruptors are rare to see. In this study we conducted virtual screening to identify candidate hit compounds targeting the WBM site of WDR5. As a result, 60 compounds were selected as candidate WBM site inhibitors. Cell proliferation assay demonstrated 6 structurally distinct WBM site inhibitors, numbering as compounds 4, 7, 11, 13, 19 and 22, which potently suppressed 3 neuroblastoma cell lines (MYCN-amplified IMR32 and LAN5 cell lines, and MYCN-unamplified SK-N-AS cell line). Among them, compound 19 suppressed the proliferation of IMR32 and LAN5 cells with EC50 values of 12.34 and 14.89 µM, respectively, and exerted a moderate inhibition on SK-N-AS cells, without affecting HEK293T cells at 20 µM. Analysis of high-resolution crystal complex structure of compound 19 against WDR5 revealed that it competitively occupied the hydrophobic pocket where V264 was located, which might disrupt the interaction of MYC with WDR5 and further MYC-medicated gene transcription. By performing RNA-seq analysis we demonstrated the differences in molecular action mechanisms of the compound 19 and a WIN site inhibitor OICR-9429. Most interestingly, we established the particularly high synergy rate by combining WBM site inhibitor 19 and the WIN site inhibitor OICR-9429, providing a novel therapeutic avenue for neuroblastoma.


Assuntos
Di-Hidropiridinas , Neuroblastoma , Humanos , Proteína Proto-Oncogênica N-Myc/genética , Células HEK293 , Compostos de Bifenilo , Neuroblastoma/tratamento farmacológico , Neuroblastoma/metabolismo , Linhagem Celular Tumoral , Peptídeos e Proteínas de Sinalização Intracelular
20.
Oral Dis ; 29(2): 515-527, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34174132

RESUMO

Adiponectin (APN) is a kind of endogenous anti-tumor adipocytokine, which exerts its function by binding to its receptors (AdipoR1 and AdipoR2). However, hyperadiponectinemia is found in some pathophysiological processes without significant protective effect, which indicates the existence of APN resistance. Here, we aimed to investigate the locoregional expression of APN in tongue squamous cell carcinoma (TSCC) tissues, and to explore the potential regulatory mechanism of APN resistance under hypoxia. Consequently, we found that the protein expression of APN and AdipoR1, but not AdipoR2, was upregulated in the early stage of TSCC and after hypoxic treatment ex vivo and in vitro. Knockdown of HIF-1α decreased the level of APN and AdipoR1, and simultaneously, HIF-1α was identified as transcriptor of the APN. Intriguingly, a regenerative feedback of HIF-1α was unexpectedly detected after application of recombinant globular APN (gAPN), which most likely contributed to the APN resistance. Furthermore, HIF-1α blockade combined with gAPN has a prominent synergistic antitumor effect, which suggested an effective amelioration in APN resistance. In all, our study revealed the possible mechanism of APN resistance under hypoxia and provides a promising strategy of bi-target treatment with APN and HIF-1α for TSCC therapy.


Assuntos
Carcinoma de Células Escamosas , Neoplasias da Língua , Humanos , Adiponectina/farmacologia , Carcinoma de Células Escamosas/patologia , Neoplasias da Língua/patologia , Hipóxia , Subunidade alfa do Fator 1 Induzível por Hipóxia
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