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1.
Cell ; 177(7): 1933-1947.e25, 2019 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-31160049

RESUMO

Heterotrimetic G proteins consist of four subfamilies (Gs, Gi/o, Gq/11, and G12/13) that mediate signaling via G-protein-coupled receptors (GPCRs), principally by receptors binding Gα C termini. G-protein-coupling profiles govern GPCR-induced cellular responses, yet receptor sequence selectivity determinants remain elusive. Here, we systematically quantified ligand-induced interactions between 148 GPCRs and all 11 unique Gα subunit C termini. For each receptor, we probed chimeric Gα subunit activation via a transforming growth factor-α (TGF-α) shedding response in HEK293 cells lacking endogenous Gq/11 and G12/13 proteins, and complemented G-protein-coupling profiles through a NanoBiT-G-protein dissociation assay. Interrogation of the dataset identified sequence-based coupling specificity features, inside and outside the transmembrane domain, which we used to develop a coupling predictor that outperforms previous methods. We used the predictor to engineer designer GPCRs selectively coupled to G12. This dataset of fine-tuned signaling mechanisms for diverse GPCRs is a valuable resource for research in GPCR signaling.


Assuntos
Proteínas Heterotriméricas de Ligação ao GTP/metabolismo , Modelos Biológicos , Receptores Acoplados a Proteínas G/metabolismo , Transdução de Sinais , Feminino , Células HEK293 , Proteínas Heterotriméricas de Ligação ao GTP/genética , Humanos , Masculino , Células PC-3 , Receptores Acoplados a Proteínas G/genética
2.
EMBO J ; 41(24): e112440, 2022 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-36354106

RESUMO

Cilia are ubiquitous eukaryotic organelles impotant for cellular motility, signaling, and sensory reception. Cilium formation requires intraflagellar transport of structural and signaling components and involves 22 different proteins organized into intraflagellar transport (IFT) complexes IFT-A and IFT-B that are transported by molecular motors. The IFT-B complex constitutes the backbone of polymeric IFT trains carrying cargo between the cilium and the cell body. Currently, high-resolution structures are only available for smaller IFT-B subcomplexes leaving > 50% structurally uncharacterized. Here, we used Alphafold to structurally model the 15-subunit IFT-B complex. The model was validated using cross-linking/mass-spectrometry data on reconstituted IFT-B complexes, X-ray scattering in solution, diffraction from crystals as well as site-directed mutagenesis and protein-binding assays. The IFT-B structure reveals an elongated and highly flexible complex consistent with cryo-electron tomographic reconstructions of IFT trains. The IFT-B complex organizes into IFT-B1 and IFT-B2 parts with binding sites for ciliary cargo and the inactive IFT dynein motor, respectively. Interestingly, our results are consistent with two different binding sites for IFT81/74 on IFT88/70/52/46 suggesting the possibility of different structural architectures for the IFT-B1 complex. Our data present a structural framework to understand IFT-B complex assembly, function, and ciliopathy variants.


Assuntos
Cílios , Dineínas , Cílios/metabolismo , Dineínas/metabolismo , Transporte Biológico , Sítios de Ligação , Modelos Estruturais , Flagelos/metabolismo
3.
EMBO Rep ; 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38849673

RESUMO

Polarized vesicular trafficking directs specific receptors and ion channels to cilia, but the underlying mechanisms are poorly understood. Here we describe a role for DLG1, a core component of the Scribble polarity complex, in regulating ciliary protein trafficking in kidney epithelial cells. Conditional knockout of Dlg1 in mouse kidney causes ciliary elongation and cystogenesis, and cell-based proximity labeling proteomics and fluorescence microscopy show alterations in the ciliary proteome upon loss of DLG1. Specifically, the retromer-associated protein SDCCAG3, IFT20, and polycystin-2 (PC2) are reduced in the cilia of DLG1-deficient cells compared to control cells. This phenotype is recapitulated in vivo and rescuable by re-expression of wild-type DLG1, but not a Congenital Anomalies of the Kidney and Urinary Tract (CAKUT)-associated DLG1 variant, p.T489R. Finally, biochemical approaches and Alpha Fold modelling suggest that SDCCAG3 and IFT20 form a complex that associates, at least indirectly, with DLG1. Our work identifies a key role for DLG1 in regulating ciliary protein composition and suggests that ciliary dysfunction of the p.T489R DLG1 variant may contribute to CAKUT.

4.
Nucleic Acids Res ; 52(W1): W333-W340, 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38795065

RESUMO

Protein-protein interaction experiments still yield many false positive interactions. The socioaffinity metric can distinguish true protein-protein interactions from noise based on available data. Here, we present WeSA (Weighted SocioAffinity), which considers large datasets of interaction proteomics data (IntAct, BioGRID, the BioPlex) to score human protein interactions and, in a statistically robust way, flag those (even from a single experiment) that are likely to be false positives. ROC analysis (using CORUM-PDB positives and Negatome negatives) shows that WeSA improves over other measures of interaction confidence. WeSA shows consistently good results over all datasets (up to: AUC = 0.93 and at best threshold: TPR = 0.84, FPR = 0.11, Precision = 0.98). WeSA is freely available without login (wesa.russelllab.org). Users can submit their own data or look for organized information on human protein interactions using the web server. Users can either retrieve available information for a list of proteins of interest or calculate scores for new experiments. The server outputs either pre-computed or updated WeSA scores for the input enriched with information from databases. The summary is presented as a table and a network-based visualization allowing the user to remove those nodes/edges that the method considers spurious.


Assuntos
Internet , Mapeamento de Interação de Proteínas , Proteômica , Software , Proteômica/métodos , Humanos , Mapeamento de Interação de Proteínas/métodos , Bases de Dados de Proteínas
5.
Ann Surg ; 2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38385252

RESUMO

OBJECTIVE: To develop a severity-adjusted, hospital-level benchmarking comparative performance report for postoperative organ space infection and antibiotic utilization in children with complicated appendicitis. BACKGROUND: No benchmarking data exist to aid hospitals in identifying and prioritizing opportunities for infection prevention or antimicrobial stewardship in children with complicated appendicitis. METHODS: This was a multicenter cohort study using NSQIP-Pediatric data from 16 hospitals participating in a regional research consortium, augmented with antibiotic utilization data obtained through supplemental chart review. Children with complicated appendicitis who underwent appendectomy from 07/01/2015 to 06/30/2020 were included. Thirty-day postoperative OSI rates and cumulative antibiotic utilization were compared between hospitals using observed-to-expected (O/E) ratios after adjusting for disease severity using mixed effects models. Hospitals were considered outliers if the 95% confidence interval for O/E ratios did not include 1.0. RESULTS: 1790 patients were included. Overall, the OSI rate was 15.6% (hospital range: 2.6-39.4%) and median cumulative antibiotic utilization was 9.0 days (range: 3.0-13.0). Across hospitals, adjusted O/E ratios ranged 5.7-fold for OSI (0.49-2.80, P=0.03) and 2.4-fold for antibiotic utilization (0.59-1.45, P<0.01). Three (19%) hospitals were outliers for OSI (1 high and 2 low performers), and eight (50%) were outliers for antibiotic utilization (5 high and 3 low utilizers). Ten (63%) hospitals were identified as outliers in one or both measures. CONCLUSIONS: A comparative performance benchmarking report may help hospitals identify and prioritize quality improvement opportunities for infection prevention and antimicrobial stewardship, as well as identify exemplar performers for dissemination of best practices.

6.
J Surg Res ; 296: 130-134, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38277948

RESUMO

INTRODUCTION: Intestinal atresia is a common cause of neonatal bowel obstruction. Atresias are often associated with other congenital anomalies. The purpose of the study was to evaluate associated anomalies, operative management, and postoperative outcomes of infants with intestinal atresia. METHODS: A review of patients presenting to a single free-standing children's hospital from March 2012 through February 2022 was performed. The variables examined were type of atresia, additional congenital anomalies, type of operative intervention, and postoperative outcomes. Standard statistical methods were utilized. RESULTS: A total of 75 patients with intestinal atresia were identified and several of these patients had multiple atresias. Isolated duodenal atresia patients were the most common (49.3%), followed by jejunal (32%) and ileal (12%). Mixed atresias were rare at 4%, with isolated pyloric and colonic also rare at 1.3% each. Malrotation was associated with 13% of patients and equally associated with duodenal and jejunoileal atresias. A low percentage (3%) of intestinal atresias was seen in conjunction with gastroschisis and concomitant malrotation. A majority of infants with duodenal atresia underwent standard duodenoduodenostomy (19% laparoscopic, 81% open). In infants with jejunoileal atresia, most underwent resection with primary anastomosis. A tapering enteroplasty was performed primarily in 13% of atresias. There were no significant differences noted in time to first feed or length of stay between those with and without tapering enteroplasty. Eleven percent of patients required subsequent intervention for stricture or small bowel obstruction. There was one death in this series. CONCLUSIONS: Consistent with other literature, duodenal atresia was the most common type of intestinal atresia. However, we demonstrated that malrotation was equally associated with duodenal and jejunoileal atresias while prior reports had shown a higher association with duodenal atresia. In our patient population, the use of tapering enteroplasty did not appear to be associated with outcomes. Overall, these infants have a low morbidity and mortality rate with a rare need for reoperation.


Assuntos
Obstrução Duodenal , Atresia Intestinal , Lactente , Recém-Nascido , Criança , Humanos , Atresia Intestinal/complicações , Atresia Intestinal/cirurgia , Obstrução Duodenal/complicações , Intestino Delgado , Jejuno/cirurgia , Estudos Retrospectivos
7.
Nucleic Acids Res ; 50(W1): W598-W610, 2022 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-35639758

RESUMO

In this study we show that protein language models can encode structural and functional information of GPCR sequences that can be used to predict their signaling and functional repertoire. We used the ESM1b protein embeddings as features and the binding information known from publicly available studies to develop PRECOGx, a machine learning predictor to explore GPCR interactions with G protein and ß-arrestin, which we made available through a new webserver (https://precogx.bioinfolab.sns.it/). PRECOGx outperformed its predecessor (e.g. PRECOG) in predicting GPCR-transducer couplings, being also able to consider all GPCR classes. The webserver also provides new functionalities, such as the projection of input sequences on a low-dimensional space describing essential features of the human GPCRome, which is used as a reference to track GPCR variants. Additionally, it allows inspection of the sequence and structural determinants responsible for coupling via the analysis of the most important attention maps used by the models as well as through predicted intramolecular contacts. We demonstrate applications of PRECOGx by predicting the impact of disease variants (ClinVar) and alternative splice forms from healthy tissues (GTEX) of human GPCRs, revealing the power to dissect system biasing mechanisms in both health and disease.


Assuntos
Aprendizado de Máquina , Receptores Acoplados a Proteínas G , Transdução de Sinais , Software , Humanos , Receptores Acoplados a Proteínas G/química , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Internet , beta-Arrestinas/química , beta-Arrestinas/metabolismo , Proteínas Heterotriméricas de Ligação ao GTP/química , Proteínas Heterotriméricas de Ligação ao GTP/metabolismo , Computadores , Predisposição Genética para Doença/genética , Processamento Alternativo/genética
8.
JAMA ; 331(12): 1035-1044, 2024 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-38530261

RESUMO

Importance: Inguinal hernia repair in preterm infants is common and is associated with considerable morbidity. Whether the inguinal hernia should be repaired prior to or after discharge from the neonatal intensive care unit is controversial. Objective: To evaluate the safety of early vs late surgical repair for preterm infants with an inguinal hernia. Design, Setting, and Participants: A multicenter randomized clinical trial including preterm infants with inguinal hernia diagnosed during initial hospitalization was conducted between September 2013 and April 2021 at 39 US hospitals. Follow-up was completed on January 3, 2023. Interventions: In the early repair strategy, infants underwent inguinal hernia repair before neonatal intensive care unit discharge. In the late repair strategy, hernia repair was planned after discharge from the neonatal intensive care unit and when the infants were older than 55 weeks' postmenstrual age. Main Outcomes and Measures: The primary outcome was occurrence of any prespecified serious adverse event during the 10-month observation period (determined by a blinded adjudication committee). The secondary outcomes included the total number of days in the hospital during the 10-month observation period. Results: Among the 338 randomized infants (172 in the early repair group and 166 in the late repair group), 320 underwent operative repair (86% were male; 2% were Asian, 30% were Black, 16% were Hispanic, 59% were White, and race and ethnicity were unknown in 9% and 4%, respectively; the mean gestational age at birth was 26.6 weeks [SD, 2.8 weeks]; the mean postnatal age at enrollment was 12 weeks [SD, 5 weeks]). Among 308 infants (91%) with complete data (159 in the early repair group and 149 in the late repair group), 44 (28%) in the early repair group vs 27 (18%) in the late repair group had at least 1 serious adverse event (risk difference, -7.9% [95% credible interval, -16.9% to 0%]; 97% bayesian posterior probability of benefit with late repair). The median number of days in the hospital during the 10-month observation period was 19.0 days (IQR, 9.8 to 35.0 days) in the early repair group vs 16.0 days (IQR, 7.0 to 38.0 days) in the late repair group (82% posterior probability of benefit with late repair). In the prespecified subgroup analyses, the probability that late repair reduced the number of infants with at least 1 serious adverse event was higher in infants with a gestational age younger than 28 weeks and in those with bronchopulmonary dysplasia (99% probability of benefit in each subgroup). Conclusions and Relevance: Among preterm infants with inguinal hernia, the late repair strategy resulted in fewer infants having at least 1 serious adverse event. These findings support delaying inguinal hernia repair until after initial discharge from the neonatal intensive care unit. Trial Registration: ClinicalTrials.gov Identifier: NCT01678638.


Assuntos
Hérnia Inguinal , Herniorrafia , Recém-Nascido Prematuro , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Asiático/estatística & dados numéricos , Teorema de Bayes , Idade Gestacional , Hérnia Inguinal/epidemiologia , Hérnia Inguinal/etnologia , Hérnia Inguinal/cirurgia , Herniorrafia/efeitos adversos , Herniorrafia/métodos , Herniorrafia/estatística & dados numéricos , Alta do Paciente , Fatores Etários , Hispânico ou Latino/estatística & dados numéricos , Brancos/estatística & dados numéricos , Estados Unidos/epidemiologia , Negro ou Afro-Americano/estatística & dados numéricos
9.
Ann Surg ; 278(4): e863-e869, 2023 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-36317528

RESUMO

OBJECTIVE: To evaluate whether redosing antibiotics within an hour of incision is associated with a reduction in incisional surgical site infection (iSSI) in children with appendicitis. BACKGROUND: Existing data remain conflicting as to whether children with appendicitis receiving antibiotics at diagnosis benefit from antibiotic redosing before incision. METHODS: This was a multicenter retrospective cohort study using data from the Pediatric National Surgical Quality Improvement Program augmented with antibiotic utilization and operative report data obtained though supplemental chart review. Children undergoing appendectomy at 14 hospitals participating in the Eastern Pediatric Surgery Network from July 2016 to June 2020 who received antibiotics upon diagnosis of appendicitis between 1 and 6 hours before incision were included. Multivariable logistic regression was used to compare odds of iSSI in those who were and were not redosed with antibiotics within 1 hour of incision, adjusting for patient demographics, disease severity, antibiotic agents, and hospital-level clustering of events. RESULTS: A total of 3533 children from 14 hospitals were included. Overall, 46.5% were redosed (hospital range: 1.8%-94.4%, P <0.001) and iSSI rates were similar between groups [redosed: 1.2% vs non-redosed: 1.3%; odds ratio (OR) 0.84, (95%,CI, 0.39-1.83)]. In subgroup analyses, redosing was associated with lower iSSI rates when cefoxitin was used as the initial antibiotic (redosed: 1.0% vs nonredosed: 2.5%; OR: 0.38, (95% CI, 0.17-0.84)], but no benefit was found with other antibiotic regimens, longer periods between initial antibiotic administration and incision, or with increased disease severity. CONCLUSIONS: Redosing of antibiotics within 1 hour of incision in children who received their initial dose within 6 hours of incision was not associated with reduction in risk of incisional site infection unless cefoxitin was used as the initial antibiotic.


Assuntos
Antibacterianos , Apendicite , Criança , Humanos , Antibacterianos/uso terapêutico , Infecção da Ferida Cirúrgica/epidemiologia , Infecção da Ferida Cirúrgica/etiologia , Infecção da Ferida Cirúrgica/prevenção & controle , Cefoxitina , Estudos Retrospectivos , Apendicite/complicações , Resultado do Tratamento , Apendicectomia/efeitos adversos
10.
Ann Surg ; 2023 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-37970676

RESUMO

OBJECTIVE: To compare rates of postoperative drainage and culture profiles in children with complicated appendicitis treated with the two most common antibiotic regimens with and without antipseudomonal activity (piperacillin-tazobactam [PT] and ceftriaxone with metronidazole [CM]). SUMMARY OF BACKGROUND DATA: Variation in use of antipseudomonal antibiotics has been driven by a paucity of multicenter data reporting clinically relevant, culture-based outcomes. METHODS: Retrospective cohort study of patients with complicated appendicitis (7/2015-6/2020) using NSQIP-Pediatric data from 15 hospitals participating in a regional research consortium. Operative report details, antibiotic utilization, and culture data were obtained through supplemental chart review. Rates of 30-day postoperative drainage and organism-specific culture positivity were compared between groups using mixed effects regression to adjust for clustering after propensity matching on measures of disease severity. RESULTS: 1002 children met criteria for matching (58.9% received CM and 41.1% received PT). In the matched sample of 778 patients, children treated with PT had similar rates of drainage overall (PT: 11.8%, CM: 12.1%; OR 1.44 [OR:0.71-2.94]) and higher rates of drainage associated with growth of any organism (PT: 7.7%, CM: 4.6%; OR 2.41 [95%CI:1.08-5.39]) and Escherichia coli (PT: 4.6%, CM: 1.8%; OR 3.42 [95%CI:1.07-10.92]) compared to treatment with CM. Rates were similar between groups for drainage associated with multiple organisms (PT: 2.6%, CM: 1.5%; OR 3.81 [95%CI:0.96-15.08]) and Pseudomonas (PT: 1.0%, CM: 1.3%; OR 3.42 [95%CI:0.55-21.28]). CONCLUSIONS AND RELEVANCE: Use of antipseudomonal antibiotics is not associated with lower rates of postoperative drainage procedures or more favorable culture profiles in children with complicated appendicitis.

11.
Haematologica ; 108(2): 543-554, 2023 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-35522148

RESUMO

Histone methylation-modifiers, such as EZH2 and KMT2D, are recurrently altered in B-cell lymphomas. To comprehensively describe the landscape of alterations affecting genes encoding histone methylation-modifiers in lymphomagenesis we investigated whole genome and transcriptome data of 186 mature B-cell lymphomas sequenced in the ICGC MMML-Seq project. Besides confirming common alterations of KMT2D (47% of cases), EZH2 (17%), SETD1B (5%), PRDM9 (4%), KMT2C (4%), and SETD2 (4%), also identified by prior exome or RNA-sequencing studies, we here found recurrent alterations to KDM4C in chromosome 9p24, encoding a histone demethylase. Focal structural variation was the main mechanism of KDM4C alterations, and was independent from 9p24 amplification. We also identified KDM4C alterations in lymphoma cell lines including a focal homozygous deletion in a classical Hodgkin lymphoma cell line. By integrating RNA-sequencing and genome sequencing data we predict that KDM4C structural variants result in loss-offunction. By functional reconstitution studies in cell lines, we provide evidence that KDM4C can act as a tumor suppressor. Thus, we show that identification of structural variants in whole genome sequencing data adds to the comprehensive description of the mutational landscape of lymphomas and, moreover, establish KDM4C as a putative tumor suppressive gene recurrently altered in subsets of B-cell derived lymphomas.


Assuntos
Linfoma de Células B , Linfoma , Humanos , Histonas/metabolismo , Histona Desmetilases/genética , Homozigoto , Deleção de Sequência , Linfoma/genética , Linfoma de Células B/genética , Sequenciamento Completo do Genoma , RNA , Histona Desmetilases com o Domínio Jumonji/genética , Histona Desmetilases com o Domínio Jumonji/química , Histona Desmetilases com o Domínio Jumonji/metabolismo , Histona-Lisina N-Metiltransferase/genética
12.
Hematol Oncol ; 41(4): 631-643, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36994552

RESUMO

While some follicular lymphoma (FL) patients do not require treatment or experience prolonged responses, others relapse early, and little is known about genetic alterations specific to patients with a particular clinical behavior. We selected 56 grade 1-3A FL patients according to their need of treatment or timing of relapse: never treated (n = 7), non-relapsed (19), late relapse (14), early relapse or POD24 (11), and primary refractory (5). We analyzed 56 diagnostic and 12 paired relapse lymphoid tissue biopsies and performed copy number alteration (CNA) analysis and next generation sequencing (NGS). We identified six focal driver losses (1p36.32, 6p21.32, 6q14.1, 6q23.3, 9p21.3, 10q23.33) and 1p36.33 copy-neutral loss of heterozygosity (CN-LOH). By integrating CNA and NGS results, the most frequently altered genes/regions were KMT2D (79%), CREBBP (67%), TNFRSF14 (46%) and BCL2 (40%). Although we found that mutations in PIM1, FOXO1 and TMEM30A were associated with an adverse clinical behavior, definitive conclusions cannot be drawn, due to the small sample size. We identified common precursor cells harboring early oncogenic alterations of the KMT2D, CREBBP, TNFRSF14 and EP300 genes and 16p13.3-p13.2 CN-LOH. Finally, we established the functional consequences of mutations by means of protein modeling (CD79B, PLCG2, PIM1, MCL1 and IRF8). These data expand the knowledge on the genomics behind the heterogeneous FL population and, upon replication in larger cohorts, could contribute to risk stratification and the development of targeted therapies.


Assuntos
Linfoma Folicular , Humanos , Linfoma Folicular/patologia , Recidiva Local de Neoplasia , Mutação , Genômica , Recidiva
13.
FASEB J ; 36(4): e22267, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35306694

RESUMO

Peroxiredoxin-2 (Prx-2) is a critical antioxidant protein in red blood cells (RBC). Prx-2 is oxidized to a disulfide covalently-bound dimer by H2 O2 , and then reduced back by the NADPH-dependent thioredoxin-thioredoxin reductase system. The reduction of oxidized Prx-2 is relatively slow in RBCs. Since Prx-2 is highly abundant, Prx-2s' peroxidase catalytic cycle is not considered to be limiting under normal conditions. However, whether Prx-2 recycling becomes limiting when RBCs are exposed to stress is not known. Using three different model systems characterized by increased oxidative damage to RBCs spanning the physiologic (endogenous RBCs of different ages), therapeutic (cold-stored RBCs in blood banks) and pathologic (RBCs from sickle cell disease (SCD) patients and humanized SCD mice) spectrum, basal levels of Prx-2 oxidation and Prx-2 recycling kinetics after addition of H2 O2 were determined. The reduction of oxidized Prx-2 was significantly slower in older versuin older versus younger RBCs, in RBCs stored for 4-5 weeks compared to 1 week, and in RBC from pediatric SCD patients compared to RBCs from control non-SCD patients. Similarly, the rate of Prx-2 recycling was slower in humanized SCD mice compared to WT mice. Treatment of RBC with carbon monoxide (CO) to limit heme-peroxidase activity had no effect on Prx-2 recycling kinetics. Treatment with glucose attenuated slowed Prx-2 recycling in older RBCs and SCD RBCs, but not stored RBCs. In conclusion, the reduction of oxidized Prx-2 can be further slowed in RBCs, which may limit the protection afforded by this antioxidant protein in settings associated with erythrocyte stress.


Assuntos
Anemia Falciforme , Peroxirredoxinas , Idoso , Anemia Falciforme/metabolismo , Animais , Antioxidantes/metabolismo , Eritrócitos/metabolismo , Humanos , Camundongos , Peroxidase/metabolismo , Peroxirredoxinas/metabolismo
14.
Org Biomol Chem ; 21(32): 6537-6548, 2023 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-37523212

RESUMO

Uniformly deuterated sterols and biosynthetically related materials are important for neutron, NMR, tracing and bioanalysis studies as well as critical tools for the creation of improved lipid nanoparticle formulations. The production of sufficient quantities of materials relies not only on the engineering of microorganisms to selectively accumulate desired materials but also methods for the isolation, purification and characterisation of these materials to ensure their usefulness. Uniformly deuterated squalene, the universal precursor to sterols in biological systems, has been produced and characterised. Cholesterol has been produced with controlled levels of uniform deuteration, increased biosynthetic yield and a methodology developed for the extraction and purification of this material without HPLC. Two sterols, not previously produced in deuterated forms, have been prepared with uniform deuteration: 22,23-dihydrobrassicasterol and 24-methylenecholesterol. This report triples the number of sterols that have been produced with uniform deuteration, purified and characterised and provides a silylation/silver ion chromatography protocol for the separation of sterols which differ by the degree of unsaturation. The techniques for the 13C NMR analysis of deuterated sterols, site-specific deuteration levels and an analysis of key biosynthetic steps based on these data are reported.


Assuntos
Fitosteróis , Esteróis , Saccharomyces cerevisiae , Esqualeno
15.
Nucleic Acids Res ; 49(W1): W366-W374, 2021 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-34076240

RESUMO

Advances in DNA sequencing and proteomics mean that researchers must now regularly interrogate thousands of positional gene/protein changes in order to find those relevant for potential clinical application or biological insights. The abundance of already known information on protein interactions, mechanism, and tertiary structure provides the possible means to understand these changes rapidly, though a careful and systematic integration of these diverse datasets is first needed. For this purpose, we developed Mechnetor, a tool that allows users to quickly explore and visualize integrated mechanistic data for proteins or interactions of interest. Central to the system is a careful cataloguing of diverse sources of protein interaction mechanism, and an efficient means to visualize interactions between relevant and/or known protein regions. The result is a finer resolution interaction network that provides more immediate clues as to points of intervention or mechanistic understanding. Users can import protein, interactions, genetic variants or post-translational modifications and see these data in the best known mechanistic context. We demonstrate the tool with topical examples in human genetic diseases and cancer genomics. The tool is freely available at: mechnetor.russelllab.org.


Assuntos
Variação Genética , Mapeamento de Interação de Proteínas , Software , Animais , Doenças Genéticas Inatas/genética , Humanos , Internet , Camundongos , Neoplasias/genética , Domínios e Motivos de Interação entre Proteínas , Processamento de Proteína Pós-Traducional , Proteínas/genética
16.
Nucleic Acids Res ; 49(22): e131, 2021 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-34554233

RESUMO

CRISPR-Cas9 sgRNA libraries have transformed functional genetic screening and have enabled several innovative methods that rely on simultaneously targeting numerous genetic loci. Such libraries could be used in a vast number of biological systems and in the development of new technologies, but library generation is hindered by the cost, time, and sequence data required for sgRNA library synthesis. Here, we describe a rapid enzymatic method for generating robust, variant-matched libraries from any source of cDNA in under 3 h. This method, which we have named SLALOM, utilizes a custom sgRNA scaffold sequence and a novel method for detaching oligonucleotides from solid supports by a strand displacing polymerase. With this method, we constructed libraries targeting the E. coli genome and the transcriptome of developing zebrafish hearts, demonstrating its ability to expand the reach of CRISPR technology and facilitate methods requiring custom libraries.


Assuntos
Sistemas CRISPR-Cas , Animais , Proteínas Associadas a CRISPR , Enzimas de Restrição do DNA , DNA Polimerase Dirigida por DNA , Escherichia coli/genética , Corantes Fluorescentes , Técnicas Genéticas , Genoma , Proteínas de Fluorescência Verde , Humanos , Miocárdio/metabolismo , Oligonucleotídeos , RNA/biossíntese , Transcriptoma , Peixe-Zebra
17.
J Am Chem Soc ; 144(7): 2968-2979, 2022 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-35157798

RESUMO

Coronavirus disease-2019 (COVID-19), a potentially lethal respiratory illness caused by the coronavirus SARS-CoV-2, emerged in the end of 2019 and has since spread aggressively across the globe. A thorough understanding of the molecular mechanisms of cellular infection by coronaviruses is therefore of utmost importance. A critical stage in infection is the fusion between viral and host membranes. Here, we present a detailed investigation of the role of selected SARS-CoV-2 Spike fusion peptides, and the influence of calcium and cholesterol, in this fusion process. Structural information from specular neutron reflectometry and small angle neutron scattering, complemented by dynamics information from quasi-elastic and spin-echo neutron spectroscopy, revealed strikingly different functions encoded in the Spike fusion domain. Calcium drives the N-terminal of the Spike fusion domain to fully cross the host plasma membrane. Removing calcium, however, reorients the peptide back to the lipid leaflet closest to the virus, leading to significant changes in lipid fluidity and rigidity. In conjunction with other regions of the fusion domain, which are also positioned to bridge and dehydrate viral and host membranes, the molecular events leading to cell entry by SARS-CoV-2 are proposed.


Assuntos
Bicamadas Lipídicas/metabolismo , Fragmentos de Peptídeos/metabolismo , SARS-CoV-2/química , Glicoproteína da Espícula de Coronavírus/metabolismo , Sequência de Aminoácidos , Colesterol/química , Bicamadas Lipídicas/química , Fluidez de Membrana , Difração de Nêutrons , Domínios Proteicos , Espalhamento a Baixo Ângulo , Glicoproteína da Espícula de Coronavírus/química , Lipossomas Unilamelares/química , Lipossomas Unilamelares/metabolismo
18.
Pediatr Crit Care Med ; 23(13 Suppl 1 1S): e14-e24, 2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-34989702

RESUMO

OBJECTIVES: To present consensus statements and supporting literature for plasma and platelet transfusions in critically ill children with severe trauma, traumatic brain injury, and/or intracranial hemorrhage from the Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding. DESIGN: Systematic review and consensus conference of international, multidisciplinary experts in platelet and plasma transfusion management of critically ill children. SETTING: Not applicable. PATIENTS: Critically ill neonates and children with severe trauma, traumatic brain injury, and/or intracranial hemorrhage. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: A panel of eight experts developed expert-based statements for plasma and platelet transfusions in critically ill neonates and children with severe trauma, traumatic brain injury, and/or intracranial hemorrhage. These statements were reviewed and ratified by the 29 Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding experts. A systematic review was conducted using MEDLINE, EMBASE, and Cochrane Library databases, from inception to December 2020. Consensus was obtained using the Research and Development/University of California, Los Angeles Appropriateness Method. Results were summarized using the Grading of Recommendations Assessment, Development, and Evaluation method. We developed one good practice statement and six expert consensus statements. CONCLUSIONS: The lack of evidence precludes proposing recommendations on monitoring of the coagulation system and on plasma and platelets transfusion in critically ill pediatric patients with severe trauma, severe traumatic brain injury, or nontraumatic intracranial hemorrhage.


Assuntos
Anemia , Lesões Encefálicas Traumáticas , Anemia/etiologia , Anemia/terapia , Transfusão de Componentes Sanguíneos , Lesões Encefálicas Traumáticas/complicações , Lesões Encefálicas Traumáticas/terapia , Criança , Cuidados Críticos , Estado Terminal/terapia , Transfusão de Eritrócitos , Medicina Baseada em Evidências/métodos , Hemorragia/etiologia , Hemorragia/terapia , Humanos , Recém-Nascido , Hemorragias Intracranianas/etiologia , Hemorragias Intracranianas/terapia , Plasma , Transfusão de Plaquetas
19.
Pediatr Crit Care Med ; 23(13 Supple 1 1S): e50-e62, 2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-34989705

RESUMO

OBJECTIVES: To present consensus statements and supporting literature for plasma and platelet transfusions in critically ill children following noncardiac surgery and critically ill children undergoing invasive procedures outside the operating room from the Transfusion and Anemia EXpertise Initiative - Control/Avoidance of Bleeding. DESIGN: Systematic review and consensus conference of international, multidisciplinary experts in platelet and plasma transfusion management of critically ill children. SETTING: Not applicable. PATIENTS: Critically ill children undergoing invasive procedures outside of the operating room or noncardiac surgery. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: A panel of 10 experts developed evidence-based and, when evidence was insufficient, expert-based statements for plasma and platelet transfusions in critically ill children following noncardiac surgery or undergoing invasive procedures outside of the operating room. These statements were reviewed and ratified by the 29 Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding experts. A systematic review was conducted using MEDLINE, EMBASE, and Cochrane Library databases, from inception to December 2020. Consensus was obtained using the Research and Development/University of California, Los Angeles Appropriateness Method. Results were summarized using the Grading of Recommendations Assessment, Development, and Evaluation method. We developed eight expert consensus statements focused on the critically ill child following noncardiac surgery and 10 expert consensus statements on the critically ill child undergoing invasive procedures outside the operating room. CONCLUSIONS: Evidence regarding plasma and platelet transfusion in critically ill children in this area is very limited. The Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding Consensus Conference developed 18 pediatric specific consensus statements regarding plasma and platelet transfusion management in these critically ill pediatric populations.


Assuntos
Anemia , Estado Terminal , Anemia/etiologia , Anemia/terapia , Transfusão de Componentes Sanguíneos , Criança , Cuidados Críticos , Estado Terminal/terapia , Transfusão de Eritrócitos , Medicina Baseada em Evidências/métodos , Hemorragia , Humanos , Salas Cirúrgicas , Plasma , Transfusão de Plaquetas
20.
Pediatr Crit Care Med ; 23(13 Supple 1 1S): e63-e73, 2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-34989706

RESUMO

OBJECTIVES: To present a list of high-priority research initiatives for the study of plasma and platelet transfusions in critically ill children from the Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding. DESIGN: Systematic review and consensus conference of international, multidisciplinary experts in platelet and plasma transfusion management of critically ill children. SETTING: Not applicable. PATIENTS: Critically ill pediatric patients at risk of bleeding and receiving plasma and/or platelet transfusions. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: A panel of 13 experts developed research priorities for the study of plasma and platelet transfusions in critically ill children which were reviewed and ratified by the 29 Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding experts. The specific priorities focused on the following subpopulations: severe trauma, traumatic brain injury, intracranial hemorrhage, cardiopulmonary bypass surgery, extracorporeal membrane oxygenation, oncologic diagnosis or stem cell transplantation, acute liver failure and/or liver transplantation, noncardiac surgery, invasive procedures outside of the operating room, and sepsis and/or disseminated intravascular coagulation. In addition, tests to guide plasma and platelet transfusion, as well as component selection and processing, were addressed. We developed four general overarching themes and 14 specific research priorities using modified Research and Development/University of California, Los Angeles methodology. CONCLUSIONS: Studies are needed to focus on the efficacy/harm, dosing, timing, and outcomes of critically ill children who receive plasma and/or platelet transfusions. The completion of these studies will facilitate the development of evidence-based recommendations.


Assuntos
Anemia , Estado Terminal , Anemia/terapia , Transfusão de Componentes Sanguíneos , Criança , Cuidados Críticos , Estado Terminal/terapia , Transfusão de Eritrócitos , Medicina Baseada em Evidências/métodos , Hemorragia/etiologia , Hemorragia/terapia , Humanos , Plasma , Transfusão de Plaquetas , Pesquisa
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