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1.
EMBO J ; 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38839993

RESUMO

The Mec1/ATR kinase is crucial for genome stability, yet the mechanism by which it prevents gross chromosomal rearrangements (GCRs) remains unknown. Here we find that in cells with deficient Mec1 signaling, GCRs accumulate due to the deregulation of multiple steps in homologous recombination (HR). Mec1 primarily suppresses GCRs through its role in activating the canonical checkpoint kinase Rad53, which ensures the proper control of DNA end resection. Upon loss of Rad53 signaling and resection control, Mec1 becomes hyperactivated and triggers a salvage pathway in which the Sgs1 helicase is recruited to sites of DNA lesions via the 911-Dpb11 scaffolds and phosphorylated by Mec1 to favor heteroduplex rejection and limit HR-driven GCR accumulation. Fusing an ssDNA recognition domain to Sgs1 bypasses the requirement of Mec1 signaling for GCR suppression and nearly eliminates D-loop formation, thus preventing non-allelic recombination events. We propose that Mec1 regulates multiple steps of HR to prevent GCRs while ensuring balanced HR usage when needed for promoting tolerance to replication stress.

2.
bioRxiv ; 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38895347

RESUMO

Tools for acute manipulation of protein localization enable elucidation of spatiotemporally defined functions, but their reliance on exogenous triggers can interfere with cell physiology. This limitation is particularly apparent for studying mitosis, whose highly choreographed events are sensitive to perturbations. Here we exploit the serendipitous discovery of a phosphorylation-controlled, cell cycle-dependent localization change of the adaptor protein PLEKHA5 to develop a system for mitosis-specific protein recruitment to the plasma membrane that requires no exogenous stimulus. Mitosis-enabled Anchor-away/Recruiter System (MARS) comprises an engineered, 15-kDa module derived from PLEKHA5 capable of recruiting functional protein cargoes to the plasma membrane during mitosis, either through direct fusion or via GFP-GFP nanobody interaction. Applications of MARS include both knock sideways to rapidly extract proteins from their native localizations during mitosis and conditional recruitment of lipid-metabolizing enzymes for mitosis-selective editing of plasma membrane lipid content, without the need for exogenous triggers or perturbative synchronization methods.

3.
Cureus ; 16(4): e58218, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38745797

RESUMO

STUDY DESIGN: This study is an ambispective evaluation and analysis of a single-center cohort. OBJECTIVE: This study aimed to evaluate the performance of a novel biphasic calcium phosphate (BCP) bone graft with submicron-sized needle-shaped surface topography (BCP<µm) in interbody arthrodesis of the lumbar spine. METHODS: This study was a single-center ambispective assessment of adult patients receiving BCP<µm as part of their lumbar interbody fusion surgery. The primary outcome was a fusion status on computed tomography (CT) 12 months postoperative. The secondary outcomes included postoperative changes in the visual analog scale (VAS), Oswestry Disability Index (ODI), Short Form 12 (SF-12), and length of stay (LOS). RESULTS: Sixty-three patients with one- to three-level anterior (48, 76%) and lateral (15, 24%) interbody fusions with posterior instrumentation were analyzed. Thirty-one participants (49%) had three or more comorbidities, including heart disease (43 participants, 68%), obesity (31 participants, 49%), and previous lumbar surgery (23 participants, 37%). The mean ODI decreased by 24. The mean SF-12 physical health and SF-12 mental health improved by a mean of 11.5 and 6.3, respectively. The mean VAS for the left leg, right leg, and back improved by a mean of 25.75, 22.07, and 37.87, respectively. Of 101 levels, 91 (90%) demonstrated complete bridging trabecular bone fusion with no evidence of supplemental fixation failure. CONCLUSION: The data of BCP<µm in interbody fusions for degenerative disease of the lumbar spine provides evidence of fusion in a complicated cohort of patients.

4.
Am J Public Health ; 114(6): 642-650, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38574318

RESUMO

Objectives. To examine sudden and unexpected or trauma-related deaths that occurred in the presence of law enforcement in Johnson County, Iowa, between 2011 and 2020. Methods. We identified deaths in the presence of law enforcement using definitions from the National Association of Medical Examiners. We obtained data, including demographics, cause and manner of death, toxicology results, and circumstances and location of event leading to death, from comprehensive medical examiner investigative reports. Results. There were 165 deaths that occurred in the presence of law enforcement: 114 were from a known disease, and 51 were either trauma related or the sudden, unexpected initial presentation of a previously unrecognized disease. Three deaths occurred in the context of physical restraint by law enforcement. Suicide was the leading manner of death among trauma-related deaths; the means of suicide was predictable based on in-custody (hanging) or precustody (firearm) circumstances. Conclusions. Our findings highlight the potential role of medical examiners and coroners in improving completeness of data on reporting death in the presence of law enforcement to public health agencies. (Am J Public Health. 2024;114(6):642-650. https://doi.org/10.2105/AJPH.2024.307616).


Assuntos
Causas de Morte , Aplicação da Lei , Humanos , Iowa/epidemiologia , Masculino , Adulto , Pessoa de Meia-Idade , Feminino , Idoso , Adolescente , Suicídio/estatística & dados numéricos , Adulto Jovem , Criança , Médicos Legistas , Pré-Escolar
5.
PLoS Genet ; 20(2): e1011175, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38377115

RESUMO

Meiotic recombination between homologous chromosomes is initiated by the formation of hundreds of programmed double-strand breaks (DSBs). Approximately 10% of these DSBs result in crossovers (COs), sites of physical DNA exchange between homologs that are critical to correct chromosome segregation. Virtually all COs are formed by coordinated efforts of the MSH4/MSH5 and MLH1/MLH3 heterodimers, the latter representing the defining marks of CO sites. The regulation of CO number and position is poorly understood, but undoubtedly requires the coordinated action of multiple repair pathways. In a previous report, we found gene-trap disruption of the DNA helicase, FANCJ (BRIP1/BACH1), elicited elevated numbers of MLH1 foci and chiasmata. In somatic cells, FANCJ interacts with numerous DNA repair proteins including MLH1, and we hypothesized that FANCJ functions with MLH1 to regulate the major CO pathway. To further elucidate the meiotic function of FANCJ, we produced three new Fancj mutant mouse lines via CRISPR/Cas9 gene editing: a full-gene deletion, truncation of the N-terminal Helicase domain, and a C-terminal dual-tagged allele. We also generated an antibody against the C-terminus of the mouse FANCJ protein. Surprisingly, none of our Fancj mutants show any change in either MLH1 focus counts during pachynema or total CO number at diakinesis of prophase I. We find evidence that FANCJ and MLH1 do not interact in meiosis; further, FANCJ does not co-localize with MSH4, MLH1, or MLH3 in meiosis. Instead, FANCJ co-localizes with BRCA1 and TOPBP1, forming discrete foci along the chromosome cores beginning in early meiotic prophase I and densely localized to unsynapsed chromosome axes in late zygonema and to the XY chromosomes in early pachynema. Fancj mutants also exhibit a subtle persistence of DSBs in pachynema. Collectively, these data indicate a role for FANCJ in early DSB repair, but they rule out a role for FANCJ in MLH1-mediated CO events.


Assuntos
Meiose , Prófase Meiótica I , Animais , Masculino , Camundongos , Alelos , DNA Helicases/genética , Reparo do DNA/genética , Meiose/genética , Prófase Meiótica I/genética
6.
Elife ; 122024 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-38391183

RESUMO

Meiotic sex chromosome inactivation (MSCI) is a critical feature of meiotic prophase I progression in males. While the ATR kinase and its activator TOPBP1 are key drivers of MSCI within the specialized sex body (SB) domain of the nucleus, how they promote silencing remains unclear given their multifaceted meiotic functions that also include DNA repair, chromosome synapsis, and SB formation. Here we report a novel mutant mouse harboring mutations in the TOPBP1-BRCT5 domain. Topbp1B5/B5 males are infertile, with impaired MSCI despite displaying grossly normal events of early prophase I, including synapsis and SB formation. Specific ATR-dependent events are disrupted, including phosphorylation and localization of the RNA:DNA helicase Senataxin. Topbp1B5/B5 spermatocytes initiate, but cannot maintain ongoing, MSCI. These findings reveal a non-canonical role for the ATR-TOPBP1 signaling axis in MSCI dynamics at advanced stages in pachynema and establish the first mouse mutant that separates ATR signaling and MSCI from SB formation.


Assuntos
Infertilidade Masculina , Meiose , Animais , Humanos , Masculino , Camundongos , Alelos , Proteínas de Transporte/genética , Reparo do DNA , Proteínas de Ligação a DNA/genética , Infertilidade Masculina/genética , Proteínas Nucleares/genética , Cromossomos Sexuais
7.
bioRxiv ; 2024 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-38293078

RESUMO

DNA-PKcs is a DNA damage sensor kinase with established roles in DNA double-strand break repair via non-homologous end joining. Recent studies have revealed additional roles of DNA-PKcs in the regulation of transcription, translation and DNA replication. However, the substrates through which DNA-PKcs regulates these processes remain largely undefined. Here we utilized quantitative phosphoproteomics to generate a high coverage map of DNA-PKcs signaling in response to ionizing radiation and mapped its interplay with the ATM kinase. Beyond the detection of the canonical S/T-Q phosphorylation motif, we uncovered a non-canonical mode of DNA-PKcs signaling targeting S/T-ψ-D/E motifs. Cross-species analysis in mouse pre-B and human HCT116 cell lines revealed splicing factors and transcriptional regulators phosphorylated at this novel motif, several of which contain SAP domains. These findings expand the list of DNA-PKcs and ATM substrates and establish a novel preferential phosphorylation motif for DNA-PKcs that connects it to proteins involved in nucleotide processes and interactions.

8.
bioRxiv ; 2023 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-38045423

RESUMO

The Mec1/ATR kinase is crucial for genome stability, yet the mechanism by which it prevents gross chromosomal rearrangements (GCRs) remains unknown. Here we find that in cells with deficient Mec1 signaling, GCRs accumulate due to the deregulation of multiple steps in homologous recombination (HR). Mec1 primarily suppresses GCRs through its role in activating the canonical checkpoint kinase Rad53, which ensures the proper control of DNA end resection. Upon loss of Rad53 signaling and resection control, Mec1 becomes hyperactivated and triggers a salvage pathway in which the Sgs1 helicase is recruited to sites of DNA lesions via the 911-Dpb11 scaffolds to favor heteroduplex rejection and limit HR-driven GCR accumulation. Fusing an ssDNA recognition domain to Sgs1 bypasses the requirement of Mec1 signaling for GCR suppression and nearly eliminates D-loop formation, thus preventing non-allelic recombination events. We propose that Mec1 regulates multiple steps of HR to prevent GCRs while ensuring balanced HR usage when needed for promoting tolerance to replication stress.

9.
Artigo em Inglês | MEDLINE | ID: mdl-38039085

RESUMO

Silk-amyloid-mussel foot protein (SAM) hydrogels made from recombinant fusion proteins containing ß-amyloid peptide, spider silk domain, and mussel foot protein (Mfp) are attractive bioadhesives as they display a unique combination of tunability, biocompatibility, bioabsorbability, strong cohesion, and underwater adhesion to a wide range of biological surfaces. To design tunable SAM hydrogels for tailored surgical repair applications, an understanding of the relationships between protein sequence and hydrogel properties is imperative. Here, we fabricated SAM hydrogels using fusion proteins of varying lengths of silk-amyloid repeats and Mfps to characterize their structure and properties. We found that increasing silk-amyloid repeats enhanced the hydrogel's ß-sheet content (r = 0.74), leading to higher cohesive strength and toughness. Additionally, increasing the Mfp length beyond the half-length of the full Mfp sequence (1/2 Mfp) decreased the ß-sheet content (r = -0.47), but increased hydrogel surface adhesion. Among different variants, the hydrogel made of 16xKLV-2Mfp displayed a high ultimate strength of 3.0 ± 0.3 MPa, an ultimate strain of 664 ± 119%, and an attractive underwater adhesivity of 416 ± 20 kPa to porcine skin. Collectively, the sequence-structure-property relationships learned from this study will be useful to guide the design of future protein adhesives with tunable characteristics for tailored surgical applications.

10.
Mol Cell ; 83(23): 4424-4437.e5, 2023 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-37944526

RESUMO

Whether synthetic genomes can power life has attracted broad interest in the synthetic biology field. Here, we report de novo synthesis of the largest eukaryotic chromosome thus far, synIV, a 1,454,621-bp yeast chromosome resulting from extensive genome streamlining and modification. We developed megachunk assembly combined with a hierarchical integration strategy, which significantly increased the accuracy and flexibility of synthetic chromosome construction. Besides the drastic sequence changes, we further manipulated the 3D structure of synIV to explore spatial gene regulation. Surprisingly, we found few gene expression changes, suggesting that positioning inside the yeast nucleoplasm plays a minor role in gene regulation. Lastly, we tethered synIV to the inner nuclear membrane via its hundreds of loxPsym sites and observed transcriptional repression of the entire chromosome, demonstrating chromosome-wide transcription manipulation without changing the DNA sequences. Our manipulation of the spatial structure of synIV sheds light on higher-order architectural design of the synthetic genomes.


Assuntos
Núcleo Celular , Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Cromossomos/genética , Genoma Fúngico , Biologia Sintética/métodos
11.
Sci Rep ; 13(1): 20218, 2023 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-37980440

RESUMO

Drainage for forestry has created ~ 1 million km of artificial waterways in Sweden, making it one of the largest human-induced environmental disturbances in the country. These extensive modifications of both peatland and mineral soil dominated landscapes still carry largely unknown, but potentially enormous environmental legacy effects. However, the consequences of contemporary ditch management strategies, such as hydrological restoration via ditch blocking or enhancing forest drainage to promote biomass production via ditch cleaning, on water resources and greenhouse gas (GHG) fluxes are unclear. To close the gap between science and management, we have developed a unique field research platform to experimentally evaluate key environmental strategies for drained northern landscapes with the aim to avoid further environmental degeneration. The Trollberget Experimental Area (TEA) includes replicated and controlled treatments applied at the catchment scale based on a BACI approach (before-after and control-impact). The treatments represent the dominant ecosystem types impacted by ditching in Sweden and the boreal zone: (1) rewetting of a drained peatland, (2) ditch cleaning in productive upland forests and (3) leaving these ditches unmanaged. Here we describe the TEA platform, report initial results, suggest ways forward for how to best manage this historical large-scale alteration of the boreal landscape, as well as warn against applying these treatments broadly before more long-term results are reported.

12.
bioRxiv ; 2023 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-37873301

RESUMO

During meiotic prophase I, recombination between homologous parental chromosomes is initiated by the formation of hundreds of programmed double-strand breaks (DSBs), each of which must be repaired with absolute fidelity to ensure genome stability of the germline. One outcome of these DSB events is the formation of Crossovers (COs), the sites of physical DNA exchange between homologs that are critical to ensure the correct segregation of parental chromosomes. However, COs account for only a small (~10%) proportion of all DSB repair events; the remaining 90% are repaired as non-crossovers (NCOs), most by synthesis dependent strand annealing. Virtually all COs are formed by coordinated efforts of the MSH4/MSH5 and MLH1/MLH3 heterodimers. The number and positioning of COs is exquisitely controlled via mechanisms that remain poorly understood, but which undoubtedly require the coordinated action of multiple repair pathways downstream of the initiating DSB. In a previous report we found evidence suggesting that the DNA helicase and Fanconi Anemia repair protein, FANCJ (BRIP1/BACH1), functions to regulate meiotic recombination in mouse. A gene-trap disruption of Fancj showed an elevated number of MLH1 foci and COs. FANCJ is known to interact with numerous DNA repair proteins in somatic cell repair contexts, including MLH1, BLM, BRCA1, and TOPBP1, and we hypothesized that FANCJ regulates CO formation through a direct interaction with MLH1 to suppress the major CO pathway. To further elucidate the function of FANCJ in meiosis, we produced three new Fancj mutant mouse lines via CRISPR/Cas9 gene editing: a full-gene deletion, a mutant line lacking the MLH1 interaction site and the N-terminal region of the Helicase domain, and a C-terminal 6xHIS-HA dual-tagged allele of Fancj. We also generated an antibody against the C-terminus of the mouse FANCJ protein. Surprisingly, while Fanconi-like phenotypes are observed within the somatic cell lineages of the full deletion Fancj line, none of the Fancj mutants show any change in either MLH1 focus counts during pachynema or total CO number at diakinesis of prophase I of meiosis. We find evidence that FANCJ and MLH1 do not interact in meiosis; further, FANCJ does not co-localize with MSH4, MLH1, or MLH3 during late prophase I. Instead, FANCJ forms discrete foci along the chromosome cores beginning in early meiotic prophase I, occasionally co-localizing with MSH4, and then becomes densely localized on unsynapsed chromosome axes in late zygonema and to the XY chromosomes in early pachynema. Strikingly, this localization strongly overlaps with BRCA1 and TOPBP1. Fancj mutants also exhibit a subtle persistence of DSBs in pachynema. Collectively, these data suggest a role for FANCJ in early DSB repair events, and possibly in the formation of NCOs, but they rule out a role for FANCJ in MLH1-mediated CO events. Thus, the role of FANCJ in meiotic cells involves different pathways and different interactors to those described in somatic cell lineages.

13.
Mol Cell ; 83(20): 3588-3590, 2023 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-37863026

RESUMO

In this issue, Joo et al.1 and Kovacs et al.2 report that the ATR kinase promotes nuclear envelope rupture through the phosphorylation of Lamin A/C, inducing processes such as cGAS-STING pathway activation, micronuclei clearance, and potentially cell death.


Assuntos
Membrana Nuclear , Nucleotidiltransferases , Membrana Nuclear/metabolismo , Nucleotidiltransferases/metabolismo , Fosforilação , Proteínas Mutadas de Ataxia Telangiectasia/genética , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo
14.
bioRxiv ; 2023 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-37781609

RESUMO

DNA targeting Class 2 CRISPR-Cas effector nucleases, including the well-studied Cas9 proteins, evolved protospacer-adjacent motif (PAM) and guide RNA interactions that sequentially license their binding and cleavage activities at protospacer target sites. Both interactions are nucleic acid sequence specific but function constitutively; thus, they provide intrinsic spatial control over DNA targeting activities but naturally lack temporal control. Here we show that engineered Cas9 fusion proteins which bind to nascent RNAs near a protospacer can facilitate spatiotemporal coupling between transcription and DNA targeting at that protospacer: Transcription-associated Cas9 Targeting (TraCT). Engineered TraCT is enabled when suboptimal PAM interactions limit basal activity in vivo and when one or more nascent RNA substrates are still tethered to the actively transcribing target DNA in cis. We further show that this phenomenon can be exploited for selective editing at one of two identical targets in distinct gene loci, or, in diploid allelic loci that are differentially transcribed. Our work demonstrates that temporal control over Cas9's targeting activity at specific DNA sites may be engineered without modifying Cas9's core domains and guide RNA components or their expression levels. More broadly, it establishes RNA binding in cis as a mechanism that can conditionally stimulate CRISPR-Cas DNA targeting in eukaryotes.

15.
Food Res Int ; 172: 113175, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37689926

RESUMO

Functional oligosaccharides are non-digestible by human gut enzymes and provide health benefits as fibers and prebiotics. The cello-oligosaccharides (COS) and xylooligosaccharides (XOS) are functional oligosaccharides obtained from xylan and cellulose, respectively, and are present in lignocellulosic material. The serial NF membranes process was performed to investigate the impact of the fractionation process on the prebiotic activity of oligosaccharides from xylan and cellulose. The NP030 (weight cut-off of 500-600 Da) and DK (weight cut-off of 150-300 Da) NF polymeric membranes were employed using defined operational conditions. The diafiltration (DF) was also investigated and it was determined that only a 1-time DF for NP030 was a more suitable strategy and improved the performance indices for short DP oligosaccharides. The short DP fractions obtained favored cell density for probiotic strains, which presented an increase on the optical density of up to 25 % after the fractionating process; enabling the use of short purified fractions in the food and pharmaceutical industry as a prebiotic ingredient.


Assuntos
Saccharum , Humanos , Xilanos , Celulose , Grão Comestível , Oligossacarídeos
16.
J Athl Train ; 2023 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-37734731

RESUMO

CONTEXT: Geographic disparities exist in trauma care (i.e., "trauma center desert") within the United States. An athletic trainer (AT) on-site at secondary schools (SSs) may help enhance collaboration with emergency medical systems and potentially lead to better outcomes following catastrophic injuries. However, access to AT services relative to the location of Level I or II (i.e., tertiary) trauma centers remain unknown. OBJECTIVE: To visualize and describe SSs distance to trauma centers and compare access to AT services across the United States. DESIGN: Cross-sectional study. SETTING: Public and private secondary schools with interscholastic athletics program in the United States. PATIENTS OR OTHER PARTICIPANTS: Survey data obtained through the Athletic Training Locations and Services (ATLAS) project database between September 2019 and April 2023. MAIN OUTCOME MEASURE(S): The minimum distance from each SS to tertiary trauma centers was calculated on Tableau Desktop by geocoding with longitude and latitude. The status and level of AT employment were obtained from ATLAS project database. The odds and percentage of access to AT services were examined by distance ranges. RESULTS: A total of 18,244 SSs were included in the analyses. Seventy-five percent of SSs (n=13,613) were located within 50 miles from tertiary trauma center. The odds of access to AT services were 2.74 [CI: 2.56-2.93] times greater in SSs located within 50 miles from tertiary trauma center (P<0.001). Additionally, SSs located > 60 miles from tertiary trauma center have decreased access to AT services (R2= 0.9192). CONCLUSION: This study highlights geographic disparity in distance to trauma care for SSs in the United States. SSs located > 60 miles from trauma centers were at reduced odds of access to AT services. Identification of geographic trends of AT services relative to the location of tertiary trauma centers is a critical first step to prevent fatal consequences of catastrophic injuries.

17.
Front Psychol ; 14: 1216450, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37744584

RESUMO

Introduction: A comprehensive typology of the satisfaction of psychological needs at work and in personal life was developed and tested. The typology proposes five scenarios (Enriched, Middling, Impoverished, Work-Fulfilled, and Personal Life-Fulfilled) accounting for various profiles of employees showing distinct configurations of global and specific levels of need satisfaction at work and in personal life. Methods: The scenarios were tested in a sample of 1,024 employees. Results: Using latent profile analysis, five profiles were identified that were consistent with four or the five scenarios, either aligned (Globally Satisfied, Globally Unsatisfied) or misaligned (Globally Satisfied at Work with High Relatedness, Globally Satisfied in Personal Life with High Autonomy, and Globally Satisfied in Personal Life with Low Autonomy) across domains. No profile corresponding to the Middling scenario was observed. Discussion: The results indicate that perceived job and individual characteristics predicted membership in distinct profiles. More importantly, unlike the profile Globally Unsatisfied, the profile Globally Satisfied contributed substantially to higher well-being (vitality and lower psychological distress), and to more favorable job attitudes (job satisfaction and lower turnover intentions) and behaviors (self-rated job performance and lower absenteeism, presenteeism, and work injuries). Furthermore, two of the misaligned profiles were also substantially associated with highly desirable outcome levels.

18.
BMC Microbiol ; 23(1): 206, 2023 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-37528343

RESUMO

BACKGROUND: The microbiome of the human gut serves a role in a number of physiological processes, but can be altered through effects of age, diet, and disturbances such as antibiotics. Several studies have demonstrated that commonly used antibiotics can have sustained impacts on the diversity and the composition of the gut microbiome. The impact of the two most overused antibiotics, azithromycin, and amoxicillin, in the human microbiome has not been thoroughly described. In this study, we recruited a group of individuals and unrelated controls to decipher the effects of the commonly used antibiotics amoxicillin and azithromycin on their gut microbiomes. RESULTS: We characterized the gut microbiomes by metagenomic sequencing followed by characterization of the resulting microbial communities. We found that there were clear and sustained effects of the antibiotics on the gut microbial community with significant alterations in the representations of Bifidobacterium species in response to azithromycin (macrolide antibiotic). These results were supported by significant increases identified in putative antibiotic resistance genes associated with macrolide resistance. Importantly, we did not identify these trends in the unrelated control individuals. There were no significant changes observed in other members of the microbial community. CONCLUSIONS: As we continue to focus on the role that the gut microbiome plays and how disturbances induced by antibiotics might affect our overall health, elucidating members of the community most affected by their use is of critical importance to understanding the impacts of common antibiotics on those who take them. Clinical Trial Registration Number NCT05169255. This trial was retrospectively registered on 23-12-2021.


Assuntos
Amoxicilina , Antibacterianos , Humanos , Antibacterianos/farmacologia , Amoxicilina/farmacologia , Azitromicina/farmacologia , Metagenômica , Macrolídeos/farmacologia , Farmacorresistência Bacteriana
19.
ACS Nano ; 17(17): 17048-17057, 2023 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-37594739

RESUMO

There is a growing demand for the synthesis of high surface area carbons, also known as carbon nanoparticles (CNPs). Existing synthesis methods for high surface area carbons have limited environmental benignity and economic viability due to the requirement of multistep and batch processes and harsh activating and/or templating chemicals. Herein, we demonstrate the synthesis of high surface area CNPs from lignin, a waste byproduct, through a single-step, continuous gas phase aerosol technique without the use of activating or templating chemicals. This continuous approach requires significantly less time for synthesis: on the order of seconds in comparison to hours for conventional methods. Properties of carbon materials synthesized from lignin are controlled by temperature and residence time, and the role of these parameters inside the aerosol reactor on carbon nanoparticle size, morphology, molecular structure, and surface area is systematically investigated. Furthermore, the as-obtained carbon nanoparticles are tested for specific capacitance, and the best-performing material (surface area 925 m2/g) exhibited a specific capacitance of 247 F/g at 0.5 A/g with excellent capacity retainment of over 98% after 10,000 cycles. This is a clear demonstration of their superior performance compared with supercapacitors synthesized earlier from lignin. Overall, the simple (single-step, continuous, and rapid) operation and the avoidance of the use of activating/templating chemicals make the aerosol technique a promising candidate for the scalable and sustainable synthesis of CNPs from lignin.

20.
Elife ; 122023 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-37278514

RESUMO

The replication checkpoint is essential for accurate DNA replication and repair, and maintenance of genomic integrity when a cell is challenged with genotoxic stress. Several studies have defined the complement of proteins that change subcellular location in the budding yeast Saccharomyces cerevisiae following chemically induced DNA replication stress using methyl methanesulfonate (MMS) or hydroxyurea (HU). How these protein movements are regulated remains largely unexplored. We find that the essential checkpoint kinases Mec1 and Rad53 are responsible for regulating the subcellular localization of 159 proteins during MMS-induced replication stress. Unexpectedly, Rad53 regulation of the localization of 52 proteins is independent of its known kinase activator Mec1, and in some scenarios independent of Tel1 or the mediator proteins Rad9 and Mrc1. We demonstrate that Rad53 is phosphorylated and active following MMS exposure in cells lacking Mec1 and Tel1. This noncanonical mode of Rad53 activation depends partly on the retrograde signaling transcription factor Rtg3, which also facilitates proper DNA replication dynamics. We conclude that there are biologically important modes of Rad53 protein kinase activation that respond to replication stress and operate in parallel to Mec1 and Tel1.


Assuntos
Proteínas Serina-Treonina Quinases , Proteínas de Saccharomyces cerevisiae , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas de Ciclo Celular/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Quinase do Ponto de Checagem 2/genética , Quinase do Ponto de Checagem 2/metabolismo , Saccharomyces cerevisiae/metabolismo , Fosforilação , Dano ao DNA , Metanossulfonato de Metila/farmacologia , Replicação do DNA
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