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1.
Cell ; 187(7): 1589-1616, 2024 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-38552609

RESUMO

The last 50 years have witnessed extraordinary developments in understanding mechanisms of carcinogenesis, synthesized as the hallmarks of cancer. Despite this logical framework, our understanding of the molecular basis of systemic manifestations and the underlying causes of cancer-related death remains incomplete. Looking forward, elucidating how tumors interact with distant organs and how multifaceted environmental and physiological parameters impinge on tumors and their hosts will be crucial for advances in preventing and more effectively treating human cancers. In this perspective, we discuss complexities of cancer as a systemic disease, including tumor initiation and promotion, tumor micro- and immune macro-environments, aging, metabolism and obesity, cancer cachexia, circadian rhythms, nervous system interactions, tumor-related thrombosis, and the microbiome. Model systems incorporating human genetic variation will be essential to decipher the mechanistic basis of these phenomena and unravel gene-environment interactions, providing a modern synthesis of molecular oncology that is primed to prevent cancers and improve patient quality of life and cancer outcomes.


Assuntos
Neoplasias , Humanos , Carcinogênese , Microbiota , Neoplasias/genética , Neoplasias/patologia , Neoplasias/terapia , Obesidade/complicações , Qualidade de Vida
2.
Mol Cell ; 83(14): 2417-2433.e7, 2023 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-37348497

RESUMO

Aged hematopoietic stem cells (HSCs) display diminished self-renewal and a myeloid differentiation bias. However, the drivers and mechanisms that underpin this fundamental switch are not understood. HSCs produce genotoxic formaldehyde that requires protection by the detoxification enzymes ALDH2 and ADH5 and the Fanconi anemia (FA) DNA repair pathway. We find that the HSCs in young Aldh2-/-Fancd2-/- mice harbor a transcriptomic signature equivalent to aged wild-type HSCs, along with increased epigenetic age, telomere attrition, and myeloid-biased differentiation quantified by single HSC transplantation. In addition, the p53 response is vigorously activated in Aldh2-/-Fancd2-/- HSCs, while p53 deletion rescued this aged HSC phenotype. To further define the origins of the myeloid differentiation bias, we use a GFP genetic reporter to find a striking enrichment of Vwf+ myeloid and megakaryocyte-lineage-biased HSCs. These results indicate that metabolism-derived formaldehyde-DNA damage stimulates the p53 response in HSCs to drive accelerated aging.


Assuntos
Envelhecimento , Aldeídos , Dano ao DNA , Hematopoese , Proteína Supressora de Tumor p53 , Animais , Camundongos , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Aldeídos/metabolismo , Transcriptoma , Análise da Expressão Gênica de Célula Única , Células-Tronco Hematopoéticas/citologia , Células Mieloides/citologia , Humanos , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/patologia
3.
Mol Cell ; 80(6): 996-1012.e9, 2020 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-33147438

RESUMO

Reactive aldehydes arise as by-products of metabolism and are normally cleared by multiple families of enzymes. We find that mice lacking two aldehyde detoxifying enzymes, mitochondrial ALDH2 and cytoplasmic ADH5, have greatly shortened lifespans and develop leukemia. Hematopoiesis is disrupted profoundly, with a reduction of hematopoietic stem cells and common lymphoid progenitors causing a severely depleted acquired immune system. We show that formaldehyde is a common substrate of ALDH2 and ADH5 and establish methods to quantify elevated blood formaldehyde and formaldehyde-DNA adducts in tissues. Bone-marrow-derived progenitors actively engage DNA repair but also imprint a formaldehyde-driven mutation signature similar to aging-associated human cancer mutation signatures. Furthermore, we identify analogous genetic defects in children causing a previously uncharacterized inherited bone marrow failure and pre-leukemic syndrome. Endogenous formaldehyde clearance alone is therefore critical for hematopoiesis and in limiting mutagenesis in somatic tissues.


Assuntos
Álcool Desidrogenase/genética , Aldeído-Desidrogenase Mitocondrial/genética , Formaldeído/sangue , Leucemia/genética , Adolescente , Aldeídos/sangue , Animais , Criança , Pré-Escolar , Adutos de DNA/genética , Dano ao DNA/efeitos dos fármacos , Reparo do DNA/efeitos dos fármacos , Feminino , Formaldeído/toxicidade , Hematopoese/genética , Células-Tronco Hematopoéticas/metabolismo , Humanos , Lactente , Leucemia/sangue , Leucemia/patologia , Masculino , Camundongos , Mutação/genética , Especificidade por Substrato
4.
Nature ; 600(7887): 158-163, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34819667

RESUMO

Endogenous DNA damage can perturb transcription, triggering a multifaceted cellular response that repairs the damage, degrades RNA polymerase II and shuts down global transcription1-4. This response is absent in the human disease Cockayne syndrome, which is caused by loss of the Cockayne syndrome A (CSA) or CSB proteins5-7. However, the source of endogenous DNA damage and how this leads to the prominent degenerative features of this disease remain unknown. Here we find that endogenous formaldehyde impedes transcription, with marked physiological consequences. Mice deficient in formaldehyde clearance (Adh5-/-) and CSB (Csbm/m; Csb is also known as Ercc6) develop cachexia and neurodegeneration, and succumb to kidney failure, features that resemble human Cockayne syndrome. Using single-cell RNA sequencing, we find that formaldehyde-driven transcriptional stress stimulates the expression of the anorexiogenic peptide GDF15 by a subset of kidney proximal tubule cells. Blocking this response with an anti-GDF15 antibody alleviates cachexia in Adh5-/-Csbm/m mice. Therefore, CSB provides protection to the kidney and brain against DNA damage caused by endogenous formaldehyde, while also suppressing an anorexic endocrine signal. The activation of this signal might contribute to the cachexia observed in Cockayne syndrome as well as chemotherapy-induced anorectic weight loss. A plausible evolutionary purpose for such a response is to ensure aversion to genotoxins in food.


Assuntos
Síndrome de Cockayne , Dano ao DNA , Formaldeído/efeitos adversos , Estresse Fisiológico/efeitos dos fármacos , Transcrição Gênica/efeitos dos fármacos , Álcool Desidrogenase/deficiência , Álcool Desidrogenase/metabolismo , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/patologia , Caquexia/complicações , Síndrome de Cockayne/induzido quimicamente , Síndrome de Cockayne/complicações , Síndrome de Cockayne/genética , Síndrome de Cockayne/patologia , Enzimas Reparadoras do DNA/deficiência , Modelos Animais de Doenças , Feminino , Formaldeído/metabolismo , Fator 15 de Diferenciação de Crescimento/antagonistas & inibidores , Fator 15 de Diferenciação de Crescimento/biossíntese , Fator 15 de Diferenciação de Crescimento/genética , Túbulos Renais Proximais/efeitos dos fármacos , Túbulos Renais Proximais/metabolismo , Túbulos Renais Proximais/patologia , Masculino , Camundongos , Proteínas de Ligação a Poli-ADP-Ribose/deficiência , Insuficiência Renal/complicações , Transcrição Gênica/genética
5.
Development ; 150(11)2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-37272529

RESUMO

The mechanism of pattern formation during limb muscle development remains poorly understood. The canonical view holds that naïve limb muscle progenitor cells (MPCs) invade a pre-established pattern of muscle connective tissue, thereby forming individual muscles. Here, we show that early murine embryonic limb MPCs highly accumulate pSMAD1/5/9, demonstrating active signaling of bone morphogenetic proteins (BMP) in these cells. Overexpression of inhibitory human SMAD6 (huSMAD6) in limb MPCs abrogated BMP signaling, impaired their migration and proliferation, and accelerated myogenic lineage progression. Fewer primary myofibers developed, causing an aberrant proximodistal muscle pattern. Patterning was not disturbed when huSMAD6 was overexpressed in differentiated muscle, implying that the proximodistal muscle pattern depends on BMP-mediated expansion of MPCs before their differentiation. We show that limb MPCs differentially express Hox genes, and Hox-expressing MPCs displayed active BMP signaling. huSMAD6 overexpression caused loss of HOXA11 in early limb MPCs. In conclusion, our data show that BMP signaling controls expansion of embryonic limb MPCs as a prerequisite for establishing the proximodistal muscle pattern, a process that involves expression of Hox genes.


Assuntos
Proteínas Morfogenéticas Ósseas , Músculo Esquelético , Animais , Humanos , Camundongos , Proteínas Morfogenéticas Ósseas/metabolismo , Diferenciação Celular/fisiologia , Genes Homeobox , Músculo Esquelético/metabolismo , Mioblastos/metabolismo , Proteína Smad6/metabolismo
6.
Nature ; 579(7800): 603-608, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32132710

RESUMO

Acetaldehyde is a highly reactive, DNA-damaging metabolite that is produced upon alcohol consumption1. Impaired detoxification of acetaldehyde is common in the Asian population, and is associated with alcohol-related cancers1,2. Cells are protected against acetaldehyde-induced damage by DNA crosslink repair, which when impaired causes Fanconi anaemia (FA), a disease resulting in failure to produce blood cells and a predisposition to cancer3,4. The combined inactivation of acetaldehyde detoxification and the FA pathway induces mutation, accelerates malignancies and causes the rapid attrition of blood stem cells5-7. However, the nature of the DNA damage induced by acetaldehyde and how this is repaired remains a key question. Here we generate acetaldehyde-induced DNA interstrand crosslinks and determine their repair mechanism in Xenopus egg extracts. We find that two replication-coupled pathways repair these lesions. The first is the FA pathway, which operates using excision-analogous to the mechanism used to repair the interstrand crosslinks caused by the chemotherapeutic agent cisplatin. However, the repair of acetaldehyde-induced crosslinks results in increased mutation frequency and an altered mutational spectrum compared with the repair of cisplatin-induced crosslinks. The second repair mechanism requires replication fork convergence, but does not involve DNA incisions-instead the acetaldehyde crosslink itself is broken. The Y-family DNA polymerase REV1 completes repair of the crosslink, culminating in a distinct mutational spectrum. These results define the repair pathways of DNA interstrand crosslinks caused by an endogenous and alcohol-derived metabolite, and identify an excision-independent mechanism.


Assuntos
Acetaldeído/química , Reagentes de Ligações Cruzadas/química , Dano ao DNA , Reparo do DNA , Replicação do DNA/fisiologia , DNA/química , Etanol/química , Anemia de Fanconi/metabolismo , Animais , Cisplatino/química , Cisplatino/farmacologia , Dano ao DNA/efeitos dos fármacos , Replicação do DNA/efeitos dos fármacos , DNA Polimerase Dirigida por DNA/metabolismo , Etanol/farmacologia , Mutagênese/efeitos dos fármacos , Nucleotidiltransferases/metabolismo , Mutação Puntual/efeitos dos fármacos , Mutação Puntual/genética , Xenopus , Proteínas de Xenopus/metabolismo
7.
J Biol Chem ; 300(8): 107489, 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38908753

RESUMO

Nonribosomal peptide synthetases (NRPSs) are responsible for the production of important biologically active peptides. The large, multidomain NRPSs operate through an assembly line strategy in which the growing peptide is tethered to carrier domains that deliver the intermediates to neighboring catalytic domains. While most NRPS domains catalyze standard chemistry of amino acid activation, peptide bond formation, and product release, some canonical NRPS catalytic domains promote unexpected chemistry. The paradigm monobactam antibiotic sulfazecin is produced through the activity of a terminal thioesterase domain of SulM, which catalyzes an unusual ß-lactam-forming reaction in which the nitrogen of the C-terminal N-sulfo-2,3-diaminopropionate residue attacks its thioester tether to release the monobactam product. We have determined the structure of the thioesterase domain as both a free-standing domain and a didomain complex with the upstream holo peptidyl-carrier domain. The position of variant lid helices results in an active site pocket that is quite constrained, a feature that is likely necessary to orient the substrate properly for ß-lactam formation. Modeling of a sulfazecin tripeptide into the active site identifies a plausible binding mode identifying potential interactions for the sulfamate and the peptide backbone with Arg2849 and Asn2819, respectively. The overall structure is similar to the ß-lactone-forming thioesterase domain that is responsible for similar ring closure in the production of obafluorin. We further use these insights to enable bioinformatic analysis to identify additional, uncharacterized ß-lactam-forming biosynthetic gene clusters by genome mining.

8.
N Engl J Med ; 386(24): 2283-2294, 2022 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-35704480

RESUMO

BACKGROUND: In June 2019, the Bolivian Ministry of Health reported a cluster of cases of hemorrhagic fever that started in the municipality of Caranavi and expanded to La Paz. The cause of these cases was unknown. METHODS: We obtained samples for next-generation sequencing and virus isolation. Human and rodent specimens were tested by means of virus-specific real-time quantitative reverse-transcriptase-polymerase-chain-reaction assays, next-generation sequencing, and virus isolation. RESULTS: Nine cases of hemorrhagic fever were identified; four of the patients with this illness died. The etiologic agent was identified as Mammarenavirus Chapare mammarenavirus, or Chapare virus (CHAPV), which causes Chapare hemorrhagic fever (CHHF). Probable nosocomial transmission among health care workers was identified. Some patients with CHHF had neurologic manifestations, and those who survived had a prolonged recovery period. CHAPV RNA was detected in a variety of human body fluids (including blood; urine; nasopharyngeal, oropharyngeal, and bronchoalveolar-lavage fluid; conjunctiva; and semen) and in specimens obtained from captured small-eared pygmy rice rats (Oligoryzomys microtis). In survivors of CHHF, viral RNA was detected up to 170 days after symptom onset; CHAPV was isolated from a semen sample obtained 86 days after symptom onset. CONCLUSIONS: M. Chapare mammarenavirus was identified as the etiologic agent of CHHF. Both spillover from a zoonotic reservoir and possible person-to-person transmission were identified. This virus was detected in a rodent species, O. microtis. (Funded by the Bolivian Ministry of Health and others.).


Assuntos
Arenavirus do Novo Mundo , Febre Hemorrágica Americana , RNA Viral , Roedores , Animais , Arenavirus do Novo Mundo/genética , Arenavirus do Novo Mundo/isolamento & purificação , Bolívia/epidemiologia , Infecção Hospitalar/transmissão , Infecção Hospitalar/virologia , Transmissão de Doença Infecciosa , Febre Hemorrágica Americana/complicações , Febre Hemorrágica Americana/genética , Febre Hemorrágica Americana/transmissão , Febre Hemorrágica Americana/virologia , Febres Hemorrágicas Virais/genética , Febres Hemorrágicas Virais/transmissão , Febres Hemorrágicas Virais/virologia , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Reação em Cadeia da Polimerase , RNA Viral/genética , RNA Viral/isolamento & purificação , Ratos/virologia , Roedores/virologia , Zoonoses Virais/transmissão , Zoonoses Virais/virologia
9.
Exp Cell Res ; 438(1): 114033, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38593916

RESUMO

Regardless of the clinical response and improved patient survival observed following treatment with BRAFi like Vemurafenib (Vem), rapid development of resistance still remains as a major obstacle in melanoma therapy. In this context, we developed and characterized two acquired Vem-resistant melanoma cell lines, A375V and SK-MEL-28V, and an intrinsically Vem-resistant cell line, RPMI-7951. Altered morphology and growth rate of the resistant cell lines displayed spindle-shaped cells with filopodia formation and enhanced proliferation rate as compared to parental cells. Further in vitro characterization in 2D models confirmed the emergence of a resistant phenotype in melanoma cells. To mimic the in vivo tumor microenvironment, spheroids were developed for both parental and resistant cell lines to recognize materialization of invadopodia structures demonstrating elevated invasiveness and proliferation of resistant cells-based spheroids, especially A375V. Importantly, we validated A375V cell line in vivo to prove its tumorigenicity and drug resistance in tumor xenograft model. Taken together, our established clinically relevant Vem-resistant tumor model could be beneficial to elucidate drug resistance mechanisms, screen and identify novel anticancer therapies to overcome BRAFi resistance in melanoma.


Assuntos
Proliferação de Células , Resistencia a Medicamentos Antineoplásicos , Melanoma , Proteínas Proto-Oncogênicas B-raf , Vemurafenib , Humanos , Melanoma/tratamento farmacológico , Melanoma/patologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proteínas Proto-Oncogênicas B-raf/genética , Vemurafenib/farmacologia , Camundongos , Ensaios Antitumorais Modelo de Xenoenxerto , Esferoides Celulares/efeitos dos fármacos , Esferoides Celulares/patologia , Inibidores de Proteínas Quinases/farmacologia , Microambiente Tumoral/efeitos dos fármacos , Antineoplásicos/farmacologia , Camundongos Nus
10.
Nature ; 575(7781): 234-237, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31666700

RESUMO

The Fanconi anaemia (FA) pathway repairs DNA damage caused by endogenous and chemotherapy-induced DNA crosslinks, and responds to replication stress1,2. Genetic inactivation of this pathway by mutation of genes encoding FA complementation group (FANC) proteins impairs development, prevents blood production and promotes cancer1,3. The key molecular step in the FA pathway is the monoubiquitination of a pseudosymmetric heterodimer of FANCD2-FANCI4,5 by the FA core complex-a megadalton multiprotein E3 ubiquitin ligase6,7. Monoubiquitinated FANCD2 then recruits additional protein factors to remove the DNA crosslink or to stabilize the stalled replication fork. A molecular structure of the FA core complex would explain how it acts to maintain genome stability. Here we reconstituted an active, recombinant FA core complex, and used cryo-electron microscopy and mass spectrometry to determine its structure. The FA core complex comprises two central dimers of the FANCB and FA-associated protein of 100 kDa (FAAP100) subunits, flanked by two copies of the RING finger subunit, FANCL. These two heterotrimers act as a scaffold to assemble the remaining five subunits, resulting in an extended asymmetric structure. Destabilization of the scaffold would disrupt the entire complex, resulting in a non-functional FA pathway. Thus, the structure provides a mechanistic basis for the low numbers of patients with mutations in FANCB, FANCL and FAAP100. Despite a lack of sequence homology, FANCB and FAAP100 adopt similar structures. The two FANCL subunits are in different conformations at opposite ends of the complex, suggesting that each FANCL has a distinct role. This structural and functional asymmetry of dimeric RING finger domains may be a general feature of E3 ligases. The cryo-electron microscopy structure of the FA core complex provides a foundation for a detailed understanding of its E3 ubiquitin ligase activity and DNA interstrand crosslink repair.


Assuntos
Microscopia Crioeletrônica , Proteínas de Grupos de Complementação da Anemia de Fanconi/química , Proteínas de Grupos de Complementação da Anemia de Fanconi/ultraestrutura , Complexos Multiproteicos/química , Complexos Multiproteicos/ultraestrutura , Subunidades Proteicas/química , Animais , Galinhas , Anemia de Fanconi/enzimologia , Proteína do Grupo de Complementação L da Anemia de Fanconi/química , Proteína do Grupo de Complementação L da Anemia de Fanconi/ultraestrutura , Espectrometria de Massas , Modelos Moleculares , Domínios Proteicos , Multimerização Proteica , Relação Estrutura-Atividade , Ubiquitinação
11.
Nature ; 567(7747): 267-272, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30842657

RESUMO

Cells often use multiple pathways to repair the same DNA lesion, and the choice of pathway has substantial implications for the fidelity of genome maintenance. DNA interstrand crosslinks covalently link the two strands of DNA, and thereby block replication and transcription; the cytotoxicity of these crosslinks is exploited for chemotherapy. In Xenopus egg extracts, the collision of replication forks with interstrand crosslinks initiates two distinct repair pathways. NEIL3 glycosylase can cleave the crosslink1; however, if this fails, Fanconi anaemia proteins incise the phosphodiester backbone that surrounds the interstrand crosslink, generating a double-strand-break intermediate that is repaired by homologous recombination2. It is not known how the simpler NEIL3 pathway is prioritized over the Fanconi anaemia pathway, which can cause genomic rearrangements. Here we show that the E3 ubiquitin ligase TRAIP is required for both pathways. When two replisomes converge at an interstrand crosslink, TRAIP ubiquitylates the replicative DNA helicase CMG (the complex of CDC45, MCM2-7 and GINS). Short ubiquitin chains recruit NEIL3 through direct binding, whereas longer chains are required for the unloading of CMG by the p97 ATPase, which enables the Fanconi anaemia pathway. Thus, TRAIP controls the choice between the two known pathways of replication-coupled interstrand-crosslink repair. These results, together with our other recent findings3,4 establish TRAIP as a master regulator of CMG unloading and the response of the replisome to obstacles.


Assuntos
DNA Helicases/química , DNA Helicases/metabolismo , Reparo do DNA , DNA/química , DNA/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Animais , DNA/biossíntese , Replicação do DNA , Feminino , Humanos , Componente 7 do Complexo de Manutenção de Minicromossomo/metabolismo , N-Glicosil Hidrolases/metabolismo , Ligação Proteica , Ubiquitina/metabolismo , Ubiquitinação , Xenopus
12.
Thorax ; 79(3): 209-218, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38286619

RESUMO

OBJECTIVE: Studies in hospital settings demonstrate that there is greater guideline adherence when care is delivered by a respiratory specialist, however, this has not been explored in primary care. The aim of this study is to determine the impact integrating respiratory specialists into primary care has on the delivery of guideline adherent chronic obstructive pulmonary disease (COPD) care. METHODS: 18 general practitioner (GP) practices were randomised to provide either usual or specialist-led COPD care. Patients at participating practices were included if they had an existing diagnosis of COPD. Outcomes were measured at the individual patient level. The primary outcome was guideline adherence, assessed as achieving four or more items of the COPD care bundle. Secondary outcome measures included quality of life, number of exacerbations, number of COPD-related hospitalisations and respiratory outpatient attendances. RESULTS: 586 patients from 10 practices randomised to the intervention and 656 patients from 8 practices randomised to the control arm of the study were included. The integration of respiratory specialists into GP practices led to a statistically significant (p<0.001) improvement in the provision of guideline adherent care when compared with usual care in this cohort (92.7% vs 70.1%) (OR 4.14, 95% CI 2.14 to 8.03). CONCLUSION: This is the first study to demonstrate that guideline adherence is improved through the integration of respiratory specialists into GP practices to deliver annual COPD reviews. To facilitate changes in current healthcare practice and policy, the findings of this paper need to be viewed in combination with qualitative research exploring the acceptability of specialist integration. TRIAL REGISTRATION NUMBER: NCT03482700.


Assuntos
Medicina Geral , Doença Pulmonar Obstrutiva Crônica , Humanos , Atenção à Saúde , Qualidade de Vida
13.
Small ; 20(28): e2310797, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38368253

RESUMO

Molecularly woven materials with striking mechanical resilience, and 2D controlled topologies like textiles, fishing nets, and baskets are highly anticipated. Molecular weaving exclusively apprehended by the secondary interactions expanding to laterally grown 2D self-assemblies with retained crystalline arrangement is stimulating. The interlacing entails planar molecules screwed together to form 2D woven thin films. Here, secondary interactions led 2D interlaced molecularly woven material (2°MW) built by 1D helical threads of organic chromophores twisted together via end-to-end CH···O connections, held strongly at inter-crossing by multiple OH···N interactions to prevent slippage is presented. Whereas, 1D helical threads with face-to-face O-H···O connections sans interlacing led the non-woven material (2°NW). The polarity-driven directionality in 2°MW led the water-actuated epitaxial growth of 2D-sheets to lateral thin films restricted to nano-scale thickness. The molecularly woven thin film is self-healing, flexible, and mechanically resilient in nature, while maintaining the crystalline regularity is attributed to the supple secondary interactions (2°).

14.
Small ; 20(13): e2306824, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37975153

RESUMO

Inspired by the uranyl-imidazole interactions via nitrogen's (N's) of histidine residues in single helical protein assemblies with open framework geometry that allows through migration/coordination of metal ions. Here, preliminary components of a stable hydrogen-bonded organic framework (HOF) are designed to mimic the stable single helical open framework with imidazole residues available for Uranium (U) binding. The imidazolate-HOF (CSMCRIHOF2-S) is synthesized with solvent-directed H-bonding in 1D array and tuned hydrophobic CH-π interactions leading to single helix pattern having enhanced hydrolytic stability. De-solvation led CSMCRIHOF2-P with porous helical 1D channels are transformed in a freestanding thin film that showcased improved mass transfer and adsorption of uranyl carbonate. CSMCRIHOF2-P thin film can effectively extract ≈14.8 mg g-1 in 4 weeks period from natural seawater, with > 1.7 U/V (Uranium to Vanadium ratio) selectivity. This strategy can be extended for rational designing of hydrolytically stable, U selective HOFs to realize the massive potential of the blue economy toward sustainable energy.

15.
Nature ; 553(7687): 171-177, 2018 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-29323295

RESUMO

Haematopoietic stem cells renew blood. Accumulation of DNA damage in these cells promotes their decline, while misrepair of this damage initiates malignancies. Here we describe the features and mutational landscape of DNA damage caused by acetaldehyde, an endogenous and alcohol-derived metabolite. This damage results in DNA double-stranded breaks that, despite stimulating recombination repair, also cause chromosome rearrangements. We combined transplantation of single haematopoietic stem cells with whole-genome sequencing to show that this damage occurs in stem cells, leading to deletions and rearrangements that are indicative of microhomology-mediated end-joining repair. Moreover, deletion of p53 completely rescues the survival of aldehyde-stressed and mutated haematopoietic stem cells, but does not change the pattern or the intensity of genome instability within individual stem cells. These findings characterize the mutation of the stem-cell genome by an alcohol-derived and endogenous source of DNA damage. Furthermore, we identify how the choice of DNA-repair pathway and a stringent p53 response limit the transmission of aldehyde-induced mutations in stem cells.


Assuntos
Acetaldeído/metabolismo , Quebras de DNA de Cadeia Dupla/efeitos dos fármacos , Etanol/metabolismo , Etanol/farmacologia , Instabilidade Genômica/efeitos dos fármacos , Células-Tronco Hematopoéticas/efeitos dos fármacos , Células-Tronco Hematopoéticas/patologia , Mutação , Álcool Desidrogenase/deficiência , Álcool Desidrogenase/genética , Álcool Desidrogenase/metabolismo , Animais , Sobrevivência Celular/efeitos dos fármacos , Reparo do DNA por Junção de Extremidades , Etanol/administração & dosagem , Anemia de Fanconi/genética , Anemia de Fanconi/metabolismo , Anemia de Fanconi/patologia , Proteína do Grupo de Complementação D2 da Anemia de Fanconi/deficiência , Proteína do Grupo de Complementação D2 da Anemia de Fanconi/genética , Proteína do Grupo de Complementação D2 da Anemia de Fanconi/metabolismo , Feminino , Deleção de Genes , Genes p53/genética , Transplante de Células-Tronco Hematopoéticas , Células-Tronco Hematopoéticas/metabolismo , Autoantígeno Ku/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Reparo de DNA por Recombinação/efeitos dos fármacos , Proteína Supressora de Tumor p53/deficiência , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Sequenciamento Completo do Genoma
16.
J Biol Chem ; 298(8): 102166, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35750210

RESUMO

Siderophores are conditionally essential metabolites used by microbes for environmental iron sequestration. Most Streptomyces strains produce hydroxamate-based desferrioxamine (DFO) siderophores composed of repeating units of N1-hydroxy-cadaverine (or N1-hydroxy-putrescine) and succinate. The DFO biosynthetic operon, desABCD, is highly conserved in Streptomyces; however, expression of desABCD alone does not account for the vast structural diversity within this natural product class. Here, we report the in vitro reconstitution and biochemical characterization of four DesD orthologs from Streptomyces strains that produce unique DFO siderophores. Under in vitro conditions, all four DesD orthologs displayed similar saturation steady-state kinetics (Vmax = 0.9-2.5 µM⋅min-1) and produced the macrocyclic trimer DFOE as the favored product, suggesting a conserved role for DesD in the biosynthesis of DFO siderophores. We further synthesized a structural mimic of N1-hydroxy-N1-succinyl-cadaverine (HSC)-acyl-adenylate, the HSC-acyl sulfamoyl adenosine analog (HSC-AMS), and obtained crystal structures of DesD in the ATP-bound, AMP/PPi-bound, and HSC-AMS/Pi-bound forms. We found HSC-AMS inhibited DesD orthologs (IC50 values = 48-53 µM) leading to accumulation of linear trimeric DFOG and di-HSC at the expense of macrocyclic DFOE. Addition of exogenous PPi enhanced DesD inhibition by HSC-AMS, presumably via stabilization of the DesD-HSC-AMS complex, similar to the proposed mode of adenylate stabilization where PPi remains buried in the active site. In conclusion, our data suggest that acyl-AMS derivatives may have utility as chemical probes and bisubstrate inhibitors to reveal valuable mechanistic and structural insight for this unique family of adenylating enzymes.


Assuntos
Sideróforos , Streptomyces , Monofosfato de Adenosina/metabolismo , Cadaverina/metabolismo , Desferroxamina , Ligases/metabolismo , Streptomyces/metabolismo
17.
J Am Chem Soc ; 145(2): 953-959, 2023 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-36584283

RESUMO

DNA interstrand cross-links (ICLs) prevent DNA replication and transcription and can lead to potentially lethal events, such as cancer or bone marrow failure. ICLs are typically repaired by proteins within the Fanconi Anemia (FA) pathway, although the details of the pathway are not fully established. Methods to generate DNA containing ICLs are key to furthering the understanding of DNA cross-link repair. A major route to ICL formation in vivo involves reaction of DNA with acetaldehyde, derived from ethanol metabolism. This reaction forms a three-carbon bridged ICL involving the amino groups of adjacent guanines in opposite strands of a duplex resulting in amino and imino functionalities. A stable reduced form of the ICL has applications in understanding the recognition and repair of these types of adducts. Previous routes to creating DNA duplexes containing these adducts have involved lengthy post-DNA synthesis chemistry followed by reduction of the imine. Here, an efficient and high-yielding approach to the reduced ICL using a novel N2-((R)-4-trifluoroacetamidobutan-2-yl)-2'-deoxyguanosine phosphoramidite is described. Following standard automated DNA synthesis and deprotection, the ICL is formed overnight in over 90% yield upon incubation at room temperature with a complementary oligodeoxyribonucleotide containing 2-fluoro-2'-deoxyinosine. The cross-linked duplex displayed a melting transition 25 °C higher than control sequences. Importantly, we show using the Xenopus egg extract system that an ICL synthesized by this method is repaired by the FA pathway. The simplicity and efficiency of this methodology for preparing reduced acetaldehyde ICLs will facilitate access to these DNA architectures for future studies on cross-link repair.


Assuntos
Acetaldeído , DNA , Reagentes de Ligações Cruzadas , DNA/metabolismo , Replicação do DNA , Reparo do DNA , Dano ao DNA
18.
Emerg Infect Dis ; 29(9): 1886-1889, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37610188

RESUMO

Lymphocytic choriomeningitis virus is an underreported cause of miscarriage and neurologic disease. Surveillance remains challenging because of nonspecific symptomatology, inconsistent case reporting, and difficulties with diagnostic testing. We describe a case of acute lymphocytic choriomeningitis virus disease in a person living with HIV in Connecticut, USA, identified by using quantitative reverse transcription PCR.


Assuntos
Aborto Espontâneo , Infecções por HIV , Coriomeningite Linfocítica , Humanos , Feminino , Gravidez , Vírus da Coriomeningite Linfocítica , Connecticut/epidemiologia , Coriomeningite Linfocítica/diagnóstico , Infecções por HIV/complicações
19.
Nat Prod Rep ; 40(9): 1550-1582, 2023 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-37114973

RESUMO

Covering: up to fall 2022.Nonribosomal peptide synthetases (NRPSs) are a family of modular, multidomain enzymes that catalyze the biosynthesis of important peptide natural products, including antibiotics, siderophores, and molecules with other biological activity. The NRPS architecture involves an assembly line strategy that tethers amino acid building blocks and the growing peptides to integrated carrier protein domains that migrate between different catalytic domains for peptide bond formation and other chemical modifications. Examination of the structures of individual domains and larger multidomain proteins has identified conserved conformational states within a single module that are adopted by NRPS modules to carry out a coordinated biosynthetic strategy that is shared by diverse systems. In contrast, interactions between modules are much more dynamic and do not yet suggest conserved conformational states between modules. Here we describe the structures of NRPS protein domains and modules and discuss the implications for future natural product discovery.


Assuntos
Peptídeo Sintases , Peptídeos , Peptídeo Sintases/metabolismo , Domínio Catalítico , Domínios Proteicos
20.
Ann Surg Oncol ; 30(2): 1017-1025, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36161375

RESUMO

BACKGROUND: The American Society of Breast Surgeons recommends genetic testing (GT) for all women with breast cancer (BC), but implementation and uptake of GT has not been well-described. METHODS: A retrospective chart review was performed for newly diagnosed BC patients or patients with a newly identified recurrence of BC seen in a multidisciplinary clinic (MDBC) who were offered genetic counseling (GC) and GT. RESULTS: The 138 women attending the MDBC had a median age of 54 years and comprised non-Hispanic whites (46%), Asians (28%), Hispanics (17%), blacks (4%), and other (5%). Of the 105 (76%) patients without prior GT, 100 (95%) accepted GC, with 93 (93%) of these 100 patients undergoing GT. The patients meeting the National Comprehensive Cancer Network (NCCN) guidelines for GT were more likely to undergo GT. Testing was performed with a 67- to 84-gene panel, together with an 8- to 9-gene STAT panel if needed. Among 120 patients with reports available, including 33 patients previously tested, 15 (12%) were positive (1 BLM, 1 BRCA1, 3 BRCA2, 1 BRIP1, 1 CFTR, 1 CHEK2, 1 MUTYH, 1 PALB2, 1 PRSS1, 1 RAD50, 1 RET, and 2 TP53), 44 (37%) were negative, and 61 (51%) had an uncertain variant. The median time to STAT results (n = 50) was 8 days. The STAT results were available before surgery for 47 (98%) of the 48 STAT patients undergoing surgery. CONCLUSIONS: New BC patients attending the MDBC demonstrated high rates of acceptance of GC and GT. The combination of GC and GT can offer timely information critical to patient risk assessment and treatment planning.


Assuntos
Neoplasias da Mama , Humanos , Feminino , Pessoa de Meia-Idade , Neoplasias da Mama/genética , Neoplasias da Mama/diagnóstico , Estudos Retrospectivos , Testes Genéticos/métodos , Genes BRCA2 , Aconselhamento Genético , Predisposição Genética para Doença , Mutação em Linhagem Germinativa
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