Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.359
Filtrar
Más filtros

Intervalo de año de publicación
1.
Cell ; 174(1): 21-31.e9, 2018 06 28.
Artículo en Inglés | MEDLINE | ID: mdl-29958109

RESUMEN

In speech, the highly flexible modulation of vocal pitch creates intonation patterns that speakers use to convey linguistic meaning. This human ability is unique among primates. Here, we used high-density cortical recordings directly from the human brain to determine the encoding of vocal pitch during natural speech. We found neural populations in bilateral dorsal laryngeal motor cortex (dLMC) that selectively encoded produced pitch but not non-laryngeal articulatory movements. This neural population controlled short pitch accents to express prosodic emphasis on a word in a sentence. Other larynx cortical representations controlling voicing and longer pitch phrase contours were found at separate sites. dLMC sites also encoded vocal pitch during a non-speech singing task. Finally, direct focal stimulation of dLMC evoked laryngeal movements and involuntary vocalization, confirming its causal role in feedforward control. Together, these results reveal the neural basis for the voluntary control of vocal pitch in human speech. VIDEO ABSTRACT.


Asunto(s)
Laringe/fisiología , Corteza Motora/fisiología , Habla , Adolescente , Adulto , Mapeo Encefálico , Electrocorticografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Modelos Biológicos , Adulto Joven
2.
Mol Cell ; 82(24): 4647-4663.e8, 2022 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-36525955

RESUMEN

To explore genome organization and function in the HIV-infected brain, we applied single-nuclei transcriptomics, cell-type-specific chromosomal conformation mapping, and viral integration site sequencing (IS-seq) to frontal cortex from individuals with encephalitis (HIVE) and without (HIV+). Derepressive changes in 3D genomic compartment structures in HIVE microglia were linked to the transcriptional activation of interferon (IFN) signaling and cell migratory pathways, while transcriptional downregulation and repressive compartmentalization of neuronal health and signaling genes occurred in both HIVE and HIV+ microglia. IS-seq recovered 1,221 brain integration sites showing distinct genomic patterns compared with peripheral lymphocytes, with enrichment for sequences newly mobilized into a permissive chromatin environment after infection. Viral transcription occurred in a subset of highly activated microglia comprising 0.33% of all nuclei in HIVE brain. Our findings point to disrupted microglia-neuronal interactions in HIV and link retroviral integration to remodeling of the microglial 3D genome during infection.


Asunto(s)
Infecciones por VIH , Microglía , Humanos , Microglía/metabolismo , Encéfalo , Activación de Macrófagos , Macrófagos , Infecciones por VIH/genética
3.
Nature ; 618(7966): 721-726, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37344648

RESUMEN

The combination of optical time transfer and optical clocks opens up the possibility of large-scale free-space networks that connect both ground-based optical clocks and future space-based optical clocks. Such networks promise better tests of general relativity1-3, dark-matter searches4 and gravitational-wave detection5. The ability to connect optical clocks to a distant satellite could enable space-based very long baseline interferometry6,7, advanced satellite navigation8, clock-based geodesy2,9,10 and thousandfold improvements in intercontinental time dissemination11,12. Thus far, only optical clocks have pushed towards quantum-limited performance13. By contrast, optical time transfer has not operated at the analogous quantum limit set by the number of received photons. Here we demonstrate time transfer with near quantum-limited acquisition and timing at 10,000 times lower received power than previous approaches14-24. Over 300 km between mountaintops in Hawaii with launched powers as low as 40 µW, distant sites are synchronized to 320 attoseconds. This nearly quantum-limited operation is critical for long-distance free-space links in which photons are few and amplification costly: at 4.0 mW transmit power, this approach can support 102 dB link loss, more than sufficient for future time transfer to geosynchronous orbits.

4.
Nature ; 612(7941): 661-665, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36418400

RESUMEN

Quantum sensors are used for precision timekeeping, field sensing and quantum communication1-3. Comparisons among a distributed network of these sensors are capable of, for example, synchronizing clocks at different locations4-8. The performance of a sensor network is limited by technical challenges as well as the inherent noise associated with the quantum states used to realize the network9. For networks with only spatially localized entanglement at each node, the noise performance of the network improves at best with the square root of the number of nodes10. Here we demonstrate that spatially distributed entanglement between network nodes offers better scaling with network size. A shared quantum nondemolition measurement entangles a clock network with up to four nodes. This network provides up to 4.5 decibels better precision than one without spatially distributed entanglement, and 11.6 decibels improvement as compared to a network of sensors operating at the quantum projection noise limit. We demonstrate the generality of the approach with atomic clock and atomic interferometer protocols, in scientific and technologically relevant configurations optimized for intrinsically differential comparisons of sensor outputs.

5.
Nature ; 593(7857): 74-82, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33953415

RESUMEN

The land ice contribution to global mean sea level rise has not yet been predicted1 using ice sheet and glacier models for the latest set of socio-economic scenarios, nor using coordinated exploration of uncertainties arising from the various computer models involved. Two recent international projects generated a large suite of projections using multiple models2-8, but primarily used previous-generation scenarios9 and climate models10, and could not fully explore known uncertainties. Here we estimate probability distributions for these projections under the new scenarios11,12 using statistical emulation of the ice sheet and glacier models. We find that limiting global warming to 1.5 degrees Celsius would halve the land ice contribution to twenty-first-century sea level rise, relative to current emissions pledges. The median decreases from 25 to 13 centimetres sea level equivalent (SLE) by 2100, with glaciers responsible for half the sea level contribution. The projected Antarctic contribution does not show a clear response to the emissions scenario, owing to uncertainties in the competing processes of increasing ice loss and snowfall accumulation in a warming climate. However, under risk-averse (pessimistic) assumptions, Antarctic ice loss could be five times higher, increasing the median land ice contribution to 42 centimetres SLE under current policies and pledges, with the 95th percentile projection exceeding half a metre even under 1.5 degrees Celsius warming. This would severely limit the possibility of mitigating future coastal flooding. Given this large range (between 13 centimetres SLE using the main projections under 1.5 degrees Celsius warming and 42 centimetres SLE using risk-averse projections under current pledges), adaptation planning for twenty-first-century sea level rise must account for a factor-of-three uncertainty in the land ice contribution until climate policies and the Antarctic response are further constrained.

6.
Nat Chem Biol ; 20(10): 1329-1340, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-38783133

RESUMEN

Engineered living materials combine the advantages of biological and synthetic systems by leveraging genetic and metabolic programming to control material-wide properties. Here, we demonstrate that extracellular electron transfer (EET), a microbial respiration process, can serve as a tunable bridge between live cell metabolism and synthetic material properties. In this system, EET flux from Shewanella oneidensis to a copper catalyst controls hydrogel cross-linking via two distinct chemistries to form living synthetic polymer networks. We first demonstrate that synthetic biology-inspired design rules derived from fluorescence parameterization can be applied toward EET-based regulation of polymer network mechanics. We then program transcriptional Boolean logic gates to govern EET gene expression, which enables design of computational polymer networks that mechanically respond to combinations of molecular inputs. Finally, we control fibroblast morphology using EET as a bridge for programmed material properties. Our results demonstrate how rational genetic circuit design can emulate physiological behavior in engineered living materials.


Asunto(s)
Shewanella , Shewanella/genética , Shewanella/metabolismo , Transporte de Electrón , Transcripción Genética , Hidrogeles/química , Cobre/metabolismo , Cobre/química , Regulación Bacteriana de la Expresión Génica , Biología Sintética/métodos , Regulación de la Expresión Génica , Polímeros/química , Polímeros/metabolismo
7.
Nature ; 584(7821): 443-449, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32668443

RESUMEN

The ongoing pandemic of coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a major threat to global health1 and the medical countermeasures available so far are limited2,3. Moreover, we currently lack a thorough understanding of the mechanisms of humoral immunity to SARS-CoV-24. Here we analyse a large panel of human monoclonal antibodies that target the spike (S) glycoprotein5, and identify several that exhibit potent neutralizing activity and fully block the receptor-binding domain of the S protein (SRBD) from interacting with human angiotensin-converting enzyme 2 (ACE2). Using competition-binding, structural and functional studies, we show that the monoclonal antibodies can be clustered into classes that recognize distinct epitopes on the SRBD, as well as distinct conformational states of the S trimer. Two potently neutralizing monoclonal antibodies, COV2-2196 and COV2-2130, which recognize non-overlapping sites, bound simultaneously to the S protein and neutralized wild-type SARS-CoV-2 virus in a synergistic manner. In two mouse models of SARS-CoV-2 infection, passive transfer of COV2-2196, COV2-2130 or a combination of both of these antibodies protected mice from weight loss and reduced the viral burden and levels of inflammation in the lungs. In addition, passive transfer of either of two of the most potent ACE2-blocking monoclonal antibodies (COV2-2196 or COV2-2381) as monotherapy protected rhesus macaques from SARS-CoV-2 infection. These results identify protective epitopes on the SRBD and provide a structure-based framework for rational vaccine design and the selection of robust immunotherapeutic agents.


Asunto(s)
Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Betacoronavirus/inmunología , Infecciones por Coronavirus/inmunología , Infecciones por Coronavirus/prevención & control , Pandemias/prevención & control , Neumonía Viral/inmunología , Neumonía Viral/prevención & control , Enzima Convertidora de Angiotensina 2 , Animales , Anticuerpos Monoclonales/inmunología , Betacoronavirus/química , Unión Competitiva , COVID-19 , Línea Celular , Reacciones Cruzadas , Modelos Animales de Enfermedad , Epítopos de Linfocito B/química , Epítopos de Linfocito B/inmunología , Femenino , Humanos , Macaca mulatta , Masculino , Ratones , Persona de Mediana Edad , Pruebas de Neutralización , Peptidil-Dipeptidasa A/genética , Peptidil-Dipeptidasa A/metabolismo , Profilaxis Pre-Exposición , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo/química , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo/inmunología , SARS-CoV-2 , Síndrome Respiratorio Agudo Grave/inmunología , Glicoproteína de la Espiga del Coronavirus/química , Glicoproteína de la Espiga del Coronavirus/inmunología , Glicoproteína de la Espiga del Coronavirus/metabolismo
8.
Nucleic Acids Res ; 52(6): e32, 2024 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-38412294

RESUMEN

Data from both bulk and single-cell whole-genome DNA methylation experiments are under-utilized in many ways. This is attributable to inefficient mapping of methylation sequencing reads, routinely discarded genetic information, and neglected read-level epigenetic and genetic linkage information. We introduce the BISulfite-seq Command line User Interface Toolkit (BISCUIT) and its companion R/Bioconductor package, biscuiteer, for simultaneous extraction of genetic and epigenetic information from bulk and single-cell DNA methylation sequencing. BISCUIT's performance, flexibility and standards-compliant output allow large, complex experimental designs to be characterized on clinical timescales. BISCUIT is particularly suited for processing data from single-cell DNA methylation assays, with its excellent scalability, efficiency, and ability to greatly enhance mappability, a key challenge for single-cell studies. We also introduce the epiBED format for single-molecule analysis of coupled epigenetic and genetic information, facilitating the study of cellular and tissue heterogeneity from DNA methylation sequencing.


Asunto(s)
Metilación de ADN , Epigénesis Genética , Secuenciación de Nucleótidos de Alto Rendimiento , Programas Informáticos , Epigenómica , Análisis de Secuencia de ADN , Sulfitos
9.
Proc Natl Acad Sci U S A ; 120(52): e2314998120, 2023 Dec 26.
Artículo en Inglés | MEDLINE | ID: mdl-38127983

RESUMEN

We report the hydrogen-bonding dynamics of water to a nitrile-functionalized and plasmonic electrode surface as a function of applied voltage. The surface-enhanced two-dimensional infrared spectra exhibit hydrogen-bonded and non-hydrogen-bonded nitrile features in similar proportions, plus cross peaks between the two. Isotopic dilution experiments show that the cross peaks arise predominantly from chemical exchange between hydrogen-bonded and non-hydrogen-bonded nitriles. The chemical exchange rate depends upon voltage, with the hydrogen bond of the water to the nitriles breaking 2 to 3 times slower (>63 vs. 25 ps) under a positive as compared to a negative potential. Spectral diffusion created by hydrogen-bond fluctuations occurs on a ~1 ps timescale and is moderately potential-dependent. Timescales from molecular dynamics simulations agree qualitatively with the experiment and show that a negative voltage causes a small net displacement of water away from the surface. These results show that the voltage applied to an electrode can alter the timescales of solvent motion at its interface, which has implications for electrochemically driven reactions.

10.
Nature ; 575(7781): 229-233, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-31666694

RESUMEN

Epigenetic aberrations are widespread in cancer, yet the underlying mechanisms and causality remain poorly understood1-3. A subset of gastrointestinal stromal tumours (GISTs) lack canonical kinase mutations but instead have succinate dehydrogenase (SDH) deficiency and global DNA hyper-methylation4,5. Here, we associate this hyper-methylation with changes in genome topology that activate oncogenic programs. To investigate epigenetic alterations systematically, we mapped DNA methylation, CTCF insulators, enhancers, and chromosome topology in KIT-mutant, PDGFRA-mutant and SDH-deficient GISTs. Although these respective subtypes shared similar enhancer landscapes, we identified hundreds of putative insulators where DNA methylation replaced CTCF binding in SDH-deficient GISTs. We focused on a disrupted insulator that normally partitions a core GIST super-enhancer from the FGF4 oncogene. Recurrent loss of this insulator alters locus topology in SDH-deficient GISTs, allowing aberrant physical interaction between enhancer and oncogene. CRISPR-mediated excision of the corresponding CTCF motifs in an SDH-intact GIST model disrupted the boundary between enhancer and oncogene, and strongly upregulated FGF4 expression. We also identified a second recurrent insulator loss event near the KIT oncogene, which is also highly expressed across SDH-deficient GISTs. Finally, we established a patient-derived xenograft (PDX) from an SDH-deficient GIST that faithfully maintains the epigenetics of the parental tumour, including hypermethylation and insulator defects. This PDX model is highly sensitive to FGF receptor (FGFR) inhibition, and more so to combined FGFR and KIT inhibition, validating the functional significance of the underlying epigenetic lesions. Our study reveals how epigenetic alterations can drive oncogenic programs in the absence of canonical kinase mutations, with implications for mechanistic targeting of aberrant pathways in cancers.


Asunto(s)
Carcinogénesis/genética , Aberraciones Cromosómicas , Tumores del Estroma Gastrointestinal/genética , Tumores del Estroma Gastrointestinal/patología , Oncogenes/genética , Succinato Deshidrogenasa/deficiencia , Animales , Sistemas CRISPR-Cas/genética , Metilación de ADN , Elementos de Facilitación Genéticos/genética , Epigénesis Genética , Factor 4 de Crecimiento de Fibroblastos/genética , Tumores del Estroma Gastrointestinal/enzimología , Humanos , Ratones , Mutación , Proteínas Proto-Oncogénicas c-kit/antagonistas & inhibidores , Receptores de Factores de Crecimiento de Fibroblastos/antagonistas & inhibidores , Succinato Deshidrogenasa/genética
11.
Nature ; 570(7760): 189-193, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-31092927

RESUMEN

HIV/AIDS is a leading cause of disease burden in sub-Saharan Africa. Existing evidence has demonstrated that there is substantial local variation in the prevalence of HIV; however, subnational variation has not been investigated at a high spatial resolution across the continent. Here we explore within-country variation at a 5 × 5-km resolution in sub-Saharan Africa by estimating the prevalence of HIV among adults (aged 15-49 years) and the corresponding number of people living with HIV from 2000 to 2017. Our analysis reveals substantial within-country variation in the prevalence of HIV throughout sub-Saharan Africa and local differences in both the direction and rate of change in HIV prevalence between 2000 and 2017, highlighting the degree to which important local differences are masked when examining trends at the country level. These fine-scale estimates of HIV prevalence across space and time provide an important tool for precisely targeting the interventions that are necessary to bringing HIV infections under control in sub-Saharan Africa.


Asunto(s)
Mapeo Geográfico , Infecciones por VIH/epidemiología , Adolescente , Adulto , África del Sur del Sahara/epidemiología , Femenino , Infecciones por VIH/prevención & control , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Salud Pública/estadística & datos numéricos , Salud Pública/tendencias , Adulto Joven
12.
Nano Lett ; 24(20): 6031-6037, 2024 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-38717626

RESUMEN

Manipulating the polarization of light at the nanoscale is key to the development of next-generation optoelectronic devices. This is typically done via waveplates using optically anisotropic crystals, with thicknesses on the order of the wavelength. Here, using a novel ultrafast electron-beam-based technique sensitive to transient near fields at THz frequencies, we observe a giant anisotropy in the linear optical response in the semimetal WTe2 and demonstrate that one can tune the THz polarization using a 50 nm thick film, acting as a broadband wave plate with thickness 3 orders of magnitude smaller than the wavelength. The observed circular deflections of the electron beam are consistent with simulations tracking the trajectory of the electron beam in the near field of the THz pulse. This finding offers a promising approach to enable atomically thin THz polarization control using anisotropic semimetals and defines new approaches for characterizing THz near-field optical response at far-subwavelength length scales.

13.
BMC Genomics ; 25(1): 437, 2024 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-38698335

RESUMEN

BACKGROUND: Liver transplantation is an effective treatment for liver failure. There is a large unmet demand, even as not all donated livers are transplanted. The clinical selection criteria for donor livers based on histopathological evaluation and liver function tests are variable. We integrated transcriptomics and histopathology to characterize donor liver biopsies obtained at the time of organ recovery. We performed RNA sequencing as well as manual and artificial intelligence-based histopathology (10 accepted and 21 rejected for transplantation). RESULTS: We identified two transcriptomically distinct rejected subsets (termed rejected-1 and rejected-2), where rejected-2 exhibited a near-complete transcriptomic overlap with the accepted livers, suggesting acceptability from a molecular standpoint. Liver metabolic functional genes were similarly upregulated, and extracellular matrix genes were similarly downregulated in the accepted and rejected-2 groups compared to rejected-1. The transcriptomic pattern of the rejected-2 subset was enriched for a gene expression signature of graft success post-transplantation. Serum AST, ALT, and total bilirubin levels showed similar overlapping patterns. Additional histopathological filtering identified cases with borderline scores and extensive molecular overlap with accepted donor livers. CONCLUSIONS: Our integrated approach identified a subset of rejected donor livers that are likely suitable for transplantation, demonstrating the potential to expand the pool of transplantable livers.


Asunto(s)
Perfilación de la Expresión Génica , Trasplante de Hígado , Hígado , Donantes de Tejidos , Humanos , Hígado/metabolismo , Hígado/patología , Masculino , Persona de Mediana Edad , Femenino , Transcriptoma , Rechazo de Injerto/genética , Adulto
14.
Ann Surg ; 2024 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-39140592

RESUMEN

OBJECTIVE: To evaluate the outcome of marginal liver grafts based on the Eurotransplant extended donor criteria (ECD) criteria. SUMMARY BACKGROUND DATA: Eurotransplant uses a broad definition of ECD criteria (age >65 years, steatosis >40%, BMI >30 kg/m2, ICU stay >7 days, DCD, and certain laboratory parameters) for allocating organs to recipients who have consented to marginal grafts. Historically, marginal liver grafts were associated with increased rates of dysfunction. METHODS: Retrospective cohort analysis using the German Transplant Registry (GTR) and the US Scientific Registry of Transplant Recipients (SRTR) from 2006-2016. Results were validated with recent SRTR data (2017-2022). Donors were classified according to the Eurotransplant ECD criteria, DCD was excluded. Data were analyzed with cut-off prediction, binomial logistic regression, and multivariate Cox regression. RESULTS: The study analyzed 92,330 deceased brain-dead donors (87% SRTR) and 70,374 transplants (87% SRTR) in adult recipients. Predominant ECD factors were donor age in Germany (30%) and BMI in the US (28%). Except for donor age, grafts meeting ECD criteria were not associated with impaired 1- or 3-year survival. Cut-offs had little to no predictive value for 30-day graft survival (AUROC 0.49 - 0.52) and were nominally higher for age (72 vs. 65 years) in Germany as compared to those defined by current Eurotransplant criteria. CONCLUSIONS: The outcome of transplanted grafts from higher risk donors was nearly equal to standard donors with Eurotransplant criteria failing to predict survival of marginal grafts. Modifying ECD criteria could improve graft allocation and potentially expand the donor pool.

15.
Anal Chem ; 96(31): 12892-12900, 2024 08 06.
Artículo en Inglés | MEDLINE | ID: mdl-39051631

RESUMEN

Drug enantiomers can possess vastly different pharmacological properties, yet they are identical in their chemical composition and structural connectivity. Thus, resolving enantiomers poses a great challenge in the field of separation science. Enantiomer separations necessitate interaction of the analyte with a chiral environment─in mass spectrometry-based analysis, a common approach is through a three-point interaction with a chiral selector commonly introduced during sample preparation. In select cases, the structural difference imparted through noncovalent complexation results in enantiomer-specific structural differences, facilitating measurement using a structurally selective analytical technique such as ion mobility-mass spectrometry (IM-MS). In this work, we investigate the direct IM-MS differentiation of chiral drug compounds using mononuclear copper complexes incorporating an amino acid chiral selector. A panel of 20 chiral drugs and drug-like compounds were investigated for separation, and four l-amino acids (l-histidine, l-tryptophan, l-proline, and l-tyrosine) were evaluated as chiral selectors (CS) to provide the chiral environment necessary for differentiation. Enantiomer differentiation was achieved for four chiral molecule pairs (R/S-thalidomide, R/S-baclofen, R/S-metoprolol, and d/l-panthenol) with two-peak resolution (Rp-p) values ranging from 0.7 (>10% valley) to 1.5 (baseline separation). Calibration curves relating IM peak areas to enantiomeric concentrations enabled enantiomeric excess quantitation of racemic thalidomide and metoprolol with residuals of 5.7 and 2.5%, respectively. Theoretical models suggest that CuII and l-histidine complexation around the analyte chiral center is important for gas-phase stereoselectivity. This study demonstrates the potential of combining enantioselective noncovalent copper complexation with structurally selective IM-MS for differentiating chiral drugs and drug-like compounds.


Asunto(s)
Aminoácidos , Cobre , Espectrometría de Movilidad Iónica , Cobre/química , Estereoisomerismo , Aminoácidos/química , Aminoácidos/análisis , Espectrometría de Movilidad Iónica/métodos , Espectrometría de Masas/métodos , Preparaciones Farmacéuticas/química , Preparaciones Farmacéuticas/análisis , Complejos de Coordinación/química , Estructura Molecular
16.
Anal Chem ; 2024 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-39012783

RESUMEN

Structural mass spectrometry (MS) techniques are fast and sensitive analytical methods to identify noncovalent guest/host complexation phenomena for desirable solution-phase properties. Current MS-based studies on guest/host complexes of drug and drug-like molecules are sparse, and there is limited guidance on how to interpret MS information in the context of host nanoencapsulation and inclusion. Here, we use structural MS strategies, combining energy-resolved MS (ERMS), ion mobility-MS (IM-MS), and computational modeling, to characterize 14 chemically distinct drug and drug-like compounds for their propensity to form guest/host complexes with the widely used excipient, beta-cyclodextrin (ßCD). The majority (11/14) yielded a 1:1 guest/host complex, and ion mobility collision cross section (CCS) analysis provided subtle evidence of gas-phase compaction of complexes in both polarities. The three distinct dissociation channels observed in ERMS (i.e., charged ßCD, charged guest, and partial guest loss) were used to direct charge-site assignments for computational modeling, and structural candidates were prioritized using helium-derived CCS measurements combined with root-mean-square distance analysis. The combined analytical information from ERMS, IM-MS, and computational modeling suggested that the majority of anhydrous complexes are inclusion complexes with ßCD. Taken together, this work demonstrates a roadmap for how multiple MS-based analytical measurements can be combined to interpret the structures that guest/host complexes adopt in the absence of water.

17.
J Neuroinflammation ; 21(1): 211, 2024 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-39198925

RESUMEN

BACKGROUND: Trauma can result in systemic inflammation that leads to organ dysfunction, but the impact on the brain, particularly following extracranial insults, has been largely overlooked. METHODS: Building upon our prior findings, we aimed to understand the impact of systemic inflammation on neuroinflammatory gene transcripts in eight brain regions in rats exposed to (1) blast overpressure exposure [BOP], (2) cutaneous thermal injury [BU], (3) complex extremity injury, 3 hours (h) of tourniquet-induced ischemia, and hind limb amputation [CEI+tI+HLA], (4) BOP+BU or (5) BOP+CEI and delayed HLA [BOP+CEI+dHLA] at 6, 24, and 168 h post-injury (hpi). RESULTS: Globally, the number and magnitude of differentially expressed genes (DEGs) correlated with injury severity, systemic inflammation markers, and end-organ damage, driven by several chemokines/cytokines (Csf3, Cxcr2, Il16, and Tgfb2), neurosteroids/prostaglandins (Cyp19a1, Ptger2, and Ptger3), and markers of neurodegeneration (Gfap, Grin2b, and Homer1). Regional neuroinflammatory activity was least impacted following BOP. Non-blast trauma (in the BU and CEI+tI+HLA groups) contributed to an earlier, robust and diverse neuroinflammatory response across brain regions (up to 2-50-fold greater than that in the BOP group), while combined trauma (in the BOP+CEI+dHLA group) significantly advanced neuroinflammation in all regions except for the cerebellum. In contrast, BOP+BU resulted in differential activity of several critical neuroinflammatory-neurodegenerative markers compared to BU. t-SNE plots of DEGs demonstrated that the onset, extent, and duration of the inflammatory response are brain region dependent. Regardless of injury type, the thalamus and hypothalamus, which are critical for maintaining homeostasis, had the most DEGs. Our results indicate that neuroinflammation in all groups progressively increased or remained at peak levels over the study duration, while markers of end-organ dysfunction decreased or otherwise resolved. CONCLUSIONS: Collectively, these findings emphasize the brain's sensitivity to mediators of systemic inflammation and provide an example of immune-brain crosstalk. Follow-on molecular and behavioral investigations are warranted to understand the short- to long-term pathophysiological consequences on the brain, particularly the mechanism of blood-brain barrier breakdown, immune cell penetration-activation, and microglial activation.


Asunto(s)
Encéfalo , Inflamación , Enfermedades Neuroinflamatorias , Animales , Ratas , Encéfalo/metabolismo , Encéfalo/patología , Masculino , Inflamación/metabolismo , Enfermedades Neuroinflamatorias/metabolismo , Enfermedades Neuroinflamatorias/etiología , Ratas Sprague-Dawley , Expresión Génica , Regulación de la Expresión Génica
18.
J Virol ; 97(12): e0159523, 2023 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-38032195

RESUMEN

IMPORTANCE: Our mouse model is a powerful tool for investigating the genetic mechanisms governing central nervous system (CNS) human immunodeficiency virus type-1 (HIV-1) infection and latency in the CNS at a single-cell level. A major advantage of our model is that it uses induced pluripotent stem cell-derived microglia, which enables human genetics, including gene function and therapeutic gene manipulation, to be explored in vivo, which is more challenging to study with current hematopoietic stem cell-based models for neuroHIV. Our transgenic tracing of xenografted human cells will provide a quantitative medium to develop new molecular and epigenetic strategies for reducing the HIV-1 latent reservoir and to test the impact of therapeutic inflammation-targeting drug interventions on CNS HIV-1 latency.


Asunto(s)
Infecciones por VIH , VIH-1 , Células Madre Pluripotentes Inducidas , Microglía , Animales , Humanos , Ratones , Sistema Nervioso Central , Infecciones por VIH/metabolismo , Infecciones por VIH/patología , VIH-1/fisiología , Microglía/virología , Latencia del Virus , Xenoinjertos
19.
Bioinformatics ; 39(12)2023 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-38092060

RESUMEN

SUMMARY: In whole genome sequencing data, polymerase chain reaction amplification results in duplicate DNA fragments coming from the same location in the genome. The process of preparing a whole genome bisulfite sequencing (WGBS) library, on the other hand, can create two DNA fragments from the same location that should not be considered duplicates. Currently, only one WGBS-aware duplicate marking tool exists. However, it only works with the output from a single tool, does not accept streaming input or output, and requires a substantial amount of memory relative to the input size. Dupsifter provides an aligner-agnostic duplicate marking tool that is lightweight, has streaming capabilities, and is memory efficient. AVAILABILITY AND IMPLEMENTATION: Source code and binaries are freely available at https://github.com/huishenlab/dupsifter under the MIT license. Dupsifter is implemented in C and is supported on macOS and Linux.


Asunto(s)
Metilación de ADN , Sulfitos , Secuenciación Completa del Genoma/métodos , Análisis de Secuencia de ADN/métodos , Programas Informáticos , ADN/genética
20.
PLoS Pathog ; 18(1): e1010183, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34986207

RESUMEN

Antibodies are principal immune components elicited by vaccines to induce protection from microbial pathogens. In the Thai RV144 HIV-1 vaccine trial, vaccine efficacy was 31% and the sole primary correlate of reduced risk was shown to be vigorous antibody response targeting the V1V2 region of HIV-1 envelope. Antibodies against V3 also were inversely correlated with infection risk in subsets of vaccinees. Antibodies recognizing these regions, however, do not exhibit potent neutralizing activity. Therefore, we examined the antiviral potential of poorly neutralizing monoclonal antibodies (mAbs) against immunodominant V1V2 and V3 sites by passive administration of human mAbs to humanized mice engrafted with CD34+ hematopoietic stem cells, followed by mucosal challenge with an HIV-1 infectious molecular clone expressing the envelope of a tier 2 resistant HIV-1 strain. Treatment with anti-V1V2 mAb 2158 or anti-V3 mAb 2219 did not prevent infection, but V3 mAb 2219 displayed a superior potency compared to V1V2 mAb 2158 in reducing virus burden. While these mAbs had no or weak neutralizing activity and elicited undetectable levels of antibody-dependent cellular cytotoxicity (ADCC), V3 mAb 2219 displayed a greater capacity to bind virus- and cell-associated HIV-1 envelope and to mediate antibody-dependent cellular phagocytosis (ADCP) and C1q complement binding as compared to V1V2 mAb 2158. Mutations in the Fc region of 2219 diminished these effector activities in vitro and lessened virus control in humanized mice. These results demonstrate the importance of Fc functions other than ADCC for antibodies without potent neutralizing activity.


Asunto(s)
Productos del Gen env/inmunología , Anticuerpos Anti-VIH/farmacología , Infecciones por VIH , Carga Viral/efectos de los fármacos , Animales , Anticuerpos Monoclonales/inmunología , Anticuerpos Monoclonales/farmacología , Anticuerpos Anti-VIH/inmunología , VIH-1/inmunología , Humanos , Inmunización Pasiva , Regiones Constantes de Inmunoglobulina , Ratones , Membrana Mucosa
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA