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1.
Nature ; 600(7888): 253-258, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34880429

RESUMEN

The global terrestrial carbon sink is increasing1-3, offsetting roughly a third of anthropogenic CO2 released into the atmosphere each decade1, and thus serving to slow4 the growth of atmospheric CO2. It has been suggested that a CO2-induced long-term increase in global photosynthesis, a process known as CO2 fertilization, is responsible for a large proportion of the current terrestrial carbon sink4-7. The estimated magnitude of the historic increase in photosynthesis as result of increasing atmospheric CO2 concentrations, however, differs by an order of magnitude between long-term proxies and terrestrial biosphere models7-13. Here we quantify the historic effect of CO2 on global photosynthesis by identifying an emergent constraint14-16 that combines terrestrial biosphere models with global carbon budget estimates. Our analysis suggests that CO2 fertilization increased global annual photosynthesis by 11.85 ± 1.4%, or 13.98 ± 1.63 petagrams carbon (mean ± 95% confidence interval) between 1981 and 2020. Our results help resolve conflicting estimates of the historic sensitivity of global photosynthesis to CO2, and highlight the large impact anthropogenic emissions have had on ecosystems worldwide.


Asunto(s)
Atmósfera/química , Dióxido de Carbono/metabolismo , Mapeo Geográfico , Internacionalidad , Fotosíntesis , Secuestro de Carbono , Respiración de la Célula , Ecosistema , Actividades Humanas , Aprendizaje Automático , Plantas/metabolismo , Tecnología de Sensores Remotos , Imágenes Satelitales , Análisis Espacio-Temporal
2.
Nature ; 591(7851): 599-603, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33762765

RESUMEN

Terrestrial ecosystems remove about 30 per cent of the carbon dioxide (CO2) emitted by human activities each year1, yet the persistence of this carbon sink depends partly on how plant biomass and soil organic carbon (SOC) stocks respond to future increases in atmospheric CO2 (refs. 2,3). Although plant biomass often increases in elevated CO2 (eCO2) experiments4-6, SOC has been observed to increase, remain unchanged or even decline7. The mechanisms that drive this variation across experiments remain poorly understood, creating uncertainty in climate projections8,9. Here we synthesized data from 108 eCO2 experiments and found that the effect of eCO2 on SOC stocks is best explained by a negative relationship with plant biomass: when plant biomass is strongly stimulated by eCO2, SOC storage declines; conversely, when biomass is weakly stimulated, SOC storage increases. This trade-off appears to be related to plant nutrient acquisition, in which plants increase their biomass by mining the soil for nutrients, which decreases SOC storage. We found that, overall, SOC stocks increase with eCO2 in grasslands (8 ± 2 per cent) but not in forests (0 ± 2 per cent), even though plant biomass in grasslands increase less (9 ± 3 per cent) than in forests (23 ± 2 per cent). Ecosystem models do not reproduce this trade-off, which implies that projections of SOC may need to be revised.


Asunto(s)
Dióxido de Carbono/metabolismo , Secuestro de Carbono , Plantas/metabolismo , Suelo/química , Biomasa , Pradera , Modelos Biológicos
3.
Ann Hematol ; 103(1): 199-209, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37792064

RESUMEN

Diffuse large B-cell lymphoma (DLBCL) is a common, genomically heterogenous disease that presents a clinical challenge despite the success of frontline regimens and second-line chimeric antigen receptor T-cell (CAR-T) therapy. Recently, genomic alterations and tumor microenvironment features associated with poor CAR-T response have been identified, namely those to the TP53 tumor suppressor gene. This retrospective analysis aimed to integrate various data to identify genomic partnerships capable of providing further clarity and actionable treatment targets within this population. Publicly available data were analyzed for differential expression based on TP53 and 24-month event-free survival (EFS24) status, revealing enrichments of the BRD4 bromodomain oncogene (p < 0.0001, p = 0.001). High-BRD4 and TP53 alterations were significantly associated with lower CDKN1A (p21) and TNFRSF10B (TRAIL-R2), a key tumor suppressor and CAR-T modulator, respectively. Significant loss of CD8 T-cell presence within low-TNFRSF0B (p = 0.0042) and altered-TP53 (p = 0.0424) patients showcased relevant outcome-associated tumor microenvironment features. Furthermore, reduced expression of CDKN1A was associated with low TNFRSF10B (FDR < 0.0001) and increased BRD4 interactant genes (FDR < 0.0001). Promisingly, in vitro MDM2 inhibition with Idasnutlin and TP53 reactivation via Eprenetapopt was able to renew TNFRSF10B protein expression. Additionally, applying the BRD4-degrading PROTAC ARV-825 and the CDK4/6 inhibitor Abemaciclib as single-agents and in synergistic combination significantly reduced TP53-altered DLBCL cell line viability. Our analysis presents key associations within a genomic network of actionable targets capable of providing clarity within the evolving precision CAR-T treatment landscape.


Asunto(s)
Linfoma de Células B Grandes Difuso , Receptores Quiméricos de Antígenos , Humanos , Proteínas Nucleares , Estudios Retrospectivos , Proteína p53 Supresora de Tumor/genética , Factores de Transcripción/genética , Linfoma de Células B Grandes Difuso/tratamiento farmacológico , Linfoma de Células B Grandes Difuso/genética , Microambiente Tumoral/genética , Proteínas que Contienen Bromodominio , Proteínas de Ciclo Celular/genética , Receptores del Ligando Inductor de Apoptosis Relacionado con TNF/uso terapéutico , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/genética , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/uso terapéutico
4.
J Neurosci ; 42(19): 3896-3918, 2022 05 11.
Artículo en Inglés | MEDLINE | ID: mdl-35396327

RESUMEN

During aging, microglia produce inflammatory factors, show reduced tissue surveillance, altered interactions with synapses, and prolonged responses to CNS insults, positioning these cells to have profound impact on the function of nearby neurons. We and others recently showed that microglial attributes differ significantly across brain regions in young adult mice. However, the degree to which microglial properties vary during aging is largely unexplored. Here, we analyze and manipulate microglial aging within the basal ganglia, brain circuits that exhibit prominent regional microglial heterogeneity and where neurons are vulnerable to functional decline and neurodegenerative disease. In male and female mice, we demonstrate that VTA and SNc microglia exhibit unique and premature responses to aging, compared with cortex and NAc microglia. This is associated with localized VTA/SNc neuroinflammation that may compromise synaptic function as early as middle age. Surprisingly, systemic inflammation, local neuron death, and astrocyte aging do not appear to underlie these early aging responses of VTA and SNc microglia. Instead, we found that microglial lysosome status was tightly linked to early aging of VTA microglia. Microglial ablation/repopulation normalized VTA microglial lysosome swelling and suppressed increases in VTA microglial density during aging. In contrast, CX3CR1 receptor KO exacerbated VTA microglial lysosome rearrangements and VTA microglial proliferation during aging. Our findings reveal a previously unappreciated regional variation in onset and magnitude of microglial proliferation and inflammatory factor production during aging and highlight critical links between microglial lysosome status and local microglial responses to aging.SIGNIFICANCE STATEMENT Microglia are CNS cells that are equipped to regulate neuronal health and function throughout the lifespan. We reveal that microglia in select brain regions begin to proliferate and produce inflammatory factors in late middle age, months before microglia in other brain regions. These findings demonstrate that CNS neuroinflammation during aging is not uniform. Moreover, they raise the possibility that local microglial responses to aging play a critical role in determining which populations of neurons are most vulnerable to functional decline and neurodegenerative disease.


Asunto(s)
Microglía , Enfermedades Neurodegenerativas , Animales , Femenino , Masculino , Ratones , Enfermedades Neuroinflamatorias , Neuronas/fisiología , Sinapsis
5.
Hematol Oncol ; 41(4): 644-654, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37254453

RESUMEN

Non-follicular low-grade B-cell lymphomas (LGBCL) are biologically diverse entities that share clinical and histologic features that make definitive pathologic categorization challenging. While most patients with LGBCL have an indolent course, some experience aggressive disease, highlighting additional heterogeneity across these subtypes. To investigate the potential for shared biology across subtypes, we performed RNA sequencing and applied machine learning approaches that identified five clusters of patients that grouped independently of subtype. One cluster was characterized by inferior outcome, upregulation of cell cycle genes, and increased tumor immune cell content. Integration of whole exome sequencing identified novel LGBCL mutations and enrichment of TNFAIP3 and BCL2 alterations in the poor survival cluster. Building on this, we further refined a transcriptomic signature associated with early clinical failure in two independent cohorts. Taken together, this study identifies unique clusters of LGBCL defined by novel gene expression signatures and immune profiles associated with outcome across diagnostic subtypes.


Asunto(s)
Linfoma de Células B , Humanos , Linfoma de Células B/patología , Perfilación de la Expresión Génica , Transcriptoma
6.
J Phys Chem A ; 127(40): 8365-8373, 2023 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-37773491

RESUMEN

Aromatic chromophores possessing intramolecular hydrogen-bonds that can undergo excited-state intramolecular proton transfer (ESIPT) are critical tools for chemosensing/biosensing applications because they create large Stokes-shifted fluorescence with no overlap with the absorption spectrum to limit back-ground interferences. Classic ESIPT-active fluorophores, such as the 2-(2'-hydroxyphenyl) benzazole (HBX) series (X = NH, O, S), favor a ground-state (GS) enol (E) form that undergoes ESIPT to afford an excited-state (ES) keto (K) tautomer that generates red-shifted fluorescence. Herein, we have attached the HBX moiety to 6-methoxy-indanone (6MI) to create isomeric (ortho and para) ESIPT-active chalcone dyes and have characterized their photophysical properties in polar protic solvents (MeOH and glycerol (Gly)/MeOH mixtures) and a nonpolar aprotic (1,4-dioxane) solvent for comparison. The chalcones favor a GS E structure, which undergoes ESIPT in MeOH, Gly/MeOH mixtures, and dioxane to exclusively afford K emission with large Stokes shifts. The o-isomers possess expanded π-conjugation compared to their p-isomer counterparts, which diminishes their tendency to generate twisted intramolecular charge transfer (TICT) states. Consequently, the o-isomers have greater quantum yields and lack molecular rotor (MR) character with little K emission response to increased solvent viscosity. However, they possess strong positive solvatochromism, displaying significant blue wavelength shifts coupled with turn-on K emission in moving from polar protic MeOH to nonpolar dioxane. In contrast, the p-isomers display MR character with turn-on K emission in 75:25 Gly/MeOH compared to their emission in MeOH (up to 14-fold) due to a strong tendency for TICT. Mechanistic insight into the observed isomer-specific photophysical properties of the ESIPT-active chalcones was obtained through density functional theory (DFT) calculations. Implications for DNA biosensing applications are discussed.

8.
Eur J Neurosci ; 52(7): 3689-3709, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32281691

RESUMEN

Microglia play critical roles during CNS development and undergo dramatic changes in tissue distribution, morphology, and gene expression as they transition from embryonic to neonatal to adult microglial phenotypes. Despite the magnitude of these phenotypic shifts, little is known about the time course and dynamics of these transitions and whether they vary across brain regions. Here, we define the time course of microglial maturation in key regions of the basal ganglia in mice, where significant regional differences in microglial phenotype are present in adults. We found that microglial density peaks in the ventral tegmental area (VTA) and nucleus accumbens (NAc) during the third postnatal week, driven by a burst of microglial proliferation. Microglial abundance is then refined to adult levels through a combination of tissue expansion and microglial programmed cell death. This overproduction and refinement of microglia was significantly more pronounced in the NAc than in the VTA and was accompanied by a sharp peak in NAc microglial lysosome abundance in the third postnatal week. Collectively, these data identify a key developmental window when elevated microglial density in discrete basal ganglia nuclei may support circuit refinement and could increase susceptibility to inflammatory insults.


Asunto(s)
Microglía , Área Tegmental Ventral , Animales , Ganglios Basales , Encéfalo , Ratones , Núcleo Accumbens
9.
Global Biogeochem Cycles ; 34(11): e2020GB006598, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-33281280

RESUMEN

Across temperate North America, interannual variability (IAV) in gross primary production (GPP) and net ecosystem exchange (NEE) and their relationship with environmental drivers are poorly understood. Here, we examine IAV in GPP and NEE and their relationship to environmental drivers using two state-of-the-science flux products: NEE constrained by surface and space-based atmospheric CO2 measurements over 2010-2015 and satellite up-scaled GPP from FluxSat over 2001-2017. We show that the arid western half of temperate North America provides a larger contribution to IAV in GPP (104% of east) and NEE (127% of east) than the eastern half, in spite of smaller magnitude of annual mean GPP and NEE. This occurs because anomalies in western ecosystems are temporally coherent across the growing season leading to an amplification of GPP and NEE. In contrast, IAV in GPP and NEE in eastern ecosystems is dominated by seasonal compensation effects, associated with opposite responses to temperature anomalies in spring and summer. Terrestrial biosphere models in the MsTMIP ensemble generally capture these differences between eastern and western temperate North America, although there is considerable spread between models.

10.
Proc Natl Acad Sci U S A ; 111(6): 2241-6, 2014 Feb 11.
Artículo en Inglés | MEDLINE | ID: mdl-24469820

RESUMEN

Mechanical forces have key roles in regulating activation of T cells and coordination of the adaptive immune response. A recent example is the ability of T cells to sense the rigidity of an underlying substrate through the T-cell receptor (TCR) coreceptor CD3 and CD28, a costimulation signal essential for cell activation. In this report, we show that these two receptor systems provide complementary functions in regulating the cellular forces needed to test the mechanical properties of the extracellular environment. Traction force microscopy was carried out on primary human cells interacting with micrometer-scale elastomer pillar arrays presenting activation antibodies to CD3 and/or CD28. T cells generated traction forces of 100 pN on arrays with both antibodies. By providing one antibody or the other in solution instead of on the pillars, we show that force generation is associated with CD3 and the TCR complex. Engagement of CD28 increases traction forces associated with CD3 through the signaling pathway involving PI3K, rather than providing additional coupling between the cell and surface. Force generation is concentrated to the cell periphery and associated with molecular complexes containing phosphorylated Pyk2, suggesting that T cells use processes that share features with integrin signaling in force generation. Finally, the ability of T cells to apply forces through the TCR itself, rather than the CD3 coreceptor, was tested. Mouse cells expressing the 5C.C7 TCR exerted traction forces on pillars presenting peptide-loaded MHCs that were similar to those with α-CD3, suggesting that forces are applied to antigen-presenting cells during activation.


Asunto(s)
Antígenos CD28/fisiología , Complejo CD3/fisiología , Linfocitos T/inmunología , Antígenos CD28/inmunología , Complejo CD3/inmunología , Células Cultivadas , Humanos
11.
Nano Lett ; 16(4): 2198-204, 2016 Apr 13.
Artículo en Inglés | MEDLINE | ID: mdl-26990380

RESUMEN

We herein demonstrate the first 96-well plate platform to screen effects of micro- and nanotopographies on cell growth and proliferation. Existing high-throughput platforms test a limited number of factors and are not fully compatible with multiple types of testing and assays. This platform is compatible with high-throughput liquid handling, high-resolution imaging, and all multiwell plate-based instrumentation. We use the platform to screen for topographies and drug-topography combinations that have short- and long-term effects on T cell activation and proliferation. We coated nanofabricated "trench-grid" surfaces with anti-CD3 and anti-CD28 antibodies to activate T cells and assayed for interleukin 2 (IL-2) cytokine production. IL-2 secretion was enhanced at 200 nm trench width and >2.3 µm grating pitch; however, the secretion was suppressed at 100 nm width and <0.5 µm pitch. The enhancement on 200 nm grid trench was further amplified with the addition of blebbistatin to reduce contractility. The 200 nm grid pattern was found to triple the number of T cells in long-term expansion, a result with direct clinical applicability in adoptive immunotherapy.


Asunto(s)
Técnicas de Cultivo de Célula , Activación de Linfocitos , Nanotecnología , Linfocitos T , Animales , Técnicas de Cultivo de Célula/instrumentación , Técnicas de Cultivo de Célula/métodos , Humanos , Interleucina-2/metabolismo , Nanotecnología/instrumentación , Nanotecnología/métodos , Linfocitos T/citología , Linfocitos T/metabolismo
12.
J Phys Chem A ; 120(41): 8160-8168, 2016 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-27677341

RESUMEN

To support the development and characterization of chromophores with targeted photophysical properties, excited-state electronic structure calculations should rapidly and accurately predict how derivatization of a chromophore will affect its excitation and emission energies. This paper examines whether a time-independent excited-state density functional theory (DFT) approach meets this need through a case study of BODIPY chromophore photophysics. A restricted open-shell Kohn-Sham (ROKS) treatment of the S1 excited state of BODIPY dyes is contrasted with linear-response time-dependent density functional theory (TDDFT). Vertical excitation energies predicted by the two approaches are remarkably different due to overestimation by TDDFT and underestimation by ROKS relative to experiment. Overall, ROKS with a standard hybrid functional provides the more accurate description of the S1 excited state of BODIPY dyes, but excitation energies computed by the two methods are strongly correlated. The two approaches also make similar predictions of shifts in the excitation energy upon functionalization of the chromophore. TDDFT and ROKS models of the S1 potential energy surface are then examined in detail for a representative BODIPY dye through molecular dynamics sampling on both model surfaces. We identify the most significant differences in the sampled surfaces and analyze these differences along selected normal modes. Differences between ROKS and TDDFT descriptions of the S1 potential energy surface for this BODIPY derivative highlight the continuing need for validation of widely used approximations in excited state DFT through experimental benchmarking and comparison to ab initio reference data.

13.
Ecol Appl ; 24(6): 1478-89, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-29160668

RESUMEN

Digital repeat photography is becoming widely used for near-surface remote sensing of vegetation. Canopy greenness, which has been used extensively for phenological applications, can be readily quantified from camera images. Important questions remain, however, as to whether the observed changes in canopy greenness are directly related to changes in leaf-level traits, changes in canopy structure, or some combination thereof. We investigated relationships between canopy greenness and various metrics of canopy structure and function, using five years (2008­2012) of automated digital imagery, ground observations of phenological transitions, leaf area index (LAI) measurements, and eddy covariance estimates of gross ecosystem photosynthesis from the Harvard Forest, a temperate deciduous forest in the northeastern United States. Additionally, we sampled canopy sunlit leaves on a weekly basis throughout the growing season of 2011. We measured physiological and morphological traits including leaf size, mass (wet/dry), nitrogen content, chlorophyll fluorescence, and spectral reflectance and characterized individual leaf color with flatbed scanner imagery. Our results show that observed spring and autumn phenological transition dates are well captured by information extracted from digital repeat photography. However, spring development of both LAI and the measured physiological and morphological traits are shown to lag behind spring increases in canopy greenness, which rises very quickly to its maximum value before leaves are even half their final size. Based on the hypothesis that changes in canopy greenness represent the aggregate effect of changes in both leaf-level properties (specifically, leaf color) and changes in canopy structure (specifically, LAI), we developed a two end-member mixing model. With just a single free parameter, the model was able to reproduce the observed seasonal trajectory of canopy greenness. This analysis shows that canopy greenness is relatively insensitive to changes in LAI at high LAI levels, which we further demonstrate by assessing the impact of an ice storm on both LAI and canopy greenness. Our study provides new insights into the mechanisms driving seasonal changes in canopy greenness retrieved from digital camera imagery. The nonlinear relationship between canopy greenness and canopy LAI has important implications both for phenological research applications and for assessing responses of vegetation to disturbances.


Asunto(s)
Monitoreo del Ambiente/métodos , Bosques , Fotograbar/métodos , Conservación de los Recursos Naturales , Massachusetts , Modelos Biológicos , Hojas de la Planta , Estaciones del Año , Factores de Tiempo
14.
Nat Commun ; 15(1): 7309, 2024 Aug 24.
Artículo en Inglés | MEDLINE | ID: mdl-39181866

RESUMEN

Coordinated movement requires the nervous system to continuously compensate for changes in mechanical load across different conditions. For voluntary movements like reaching, the motor cortex is a critical hub that generates commands to move the limbs and counteract loads. How does cortex contribute to load compensation when rhythmic movements are sequenced by a spinal pattern generator? Here, we address this question by manipulating the mass of the forelimb in unrestrained mice during locomotion. While load produces changes in motor output that are robust to inactivation of motor cortex, it also induces a profound shift in cortical dynamics. This shift is minimally affected by cerebellar perturbation and significantly larger than the load response in the spinal motoneuron population. This latent representation may enable motor cortex to generate appropriate commands when a voluntary movement must be integrated with an ongoing, spinally-generated rhythm.


Asunto(s)
Locomoción , Corteza Motora , Neuronas Motoras , Animales , Corteza Motora/fisiología , Ratones , Neuronas Motoras/fisiología , Locomoción/fisiología , Miembro Anterior/fisiología , Masculino , Ratones Endogámicos C57BL , Movimiento/fisiología , Médula Espinal/fisiología , Femenino , Cerebelo/fisiología
15.
bioRxiv ; 2023 Nov 07.
Artículo en Inglés | MEDLINE | ID: mdl-37986810

RESUMEN

Coordinated movement requires the nervous system to continuously compensate for changes in mechanical load across different contexts. For voluntary movements like reaching, the motor cortex is a critical hub that generates commands to move the limbs and counteract loads. How does cortex contribute to load compensation when rhythmic movements are clocked by a spinal pattern generator? Here, we address this question by manipulating the mass of the forelimb in unrestrained mice during locomotion. While load produces changes in motor output that are robust to inactivation of motor cortex, it also induces a profound shift in cortical dynamics, which is minimally affected by cerebellar perturbation and significantly larger than the response in the spinal motoneuron population. This latent representation may enable motor cortex to generate appropriate commands when a voluntary movement must be integrated with an ongoing, spinally-generated rhythm.

16.
Diabetes ; 72(12): 1766-1780, 2023 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-37725952

RESUMEN

Maternal consumption of a Western-style diet (mWD) during pregnancy alters fatty acid metabolism and reduces insulin sensitivity in fetal skeletal muscle. The long-term impact of these fetal adaptations and the pathways underlying disordered lipid metabolism are incompletely understood. Therefore, we tested whether a mWD chronically fed to lean, insulin-sensitive adult Japanese macaques throughout pregnancy and lactation would impact skeletal muscle oxidative capacity and lipid metabolism in adolescent offspring fed a postweaning (pw) Western-style diet (WD) or control diet (CD). Although body weight was not different, retroperitoneal fat mass and subscapular skinfold thickness were significantly higher in pwWD offspring consistent with elevated fasting insulin and glucose. Maximal complex I (CI)-dependent respiration in muscle was lower in mWD offspring in the presence of fatty acids, suggesting that mWD impacts muscle integration of lipid with nonlipid oxidation. Abundance of all five oxidative phosphorylation complexes and VDAC, but not ETF/ETFDH, were reduced with mWD, partially explaining the lower respiratory capacity with lipids. Muscle triglycerides increased with pwWD; however, the fold increase in lipid saturation, 1,2-diacylglycerides, and C18 ceramide compared between pwCD and pwWD was greatest in mWD offspring. Reductions in CI abundance and VDAC correlated with reduced markers of oxidative stress, suggesting that these reductions may be an early-life adaptation to mWD to mitigate excess reactive oxygen species. Altogether, mWD, independent of maternal obesity or insulin resistance, results in sustained metabolic reprogramming in offspring muscle despite a healthy diet intervention. ARTICLE HIGHLIGHTS: In lean, active adolescent offspring, a postweaning Western-style diet (pwWD) leads to shifts in body fat distribution that are associated with poorer insulin sensitivity. Fatty acid-linked oxidative metabolism was reduced in skeletal muscles from offspring exposed to maternal Western-style diet (mWD) even when weaned to a healthy control diet for years. Reduced oxidative phosphorylation complex I-V and VDAC1 abundance partially explain decreased skeletal muscle respiration in mWD offspring. Prior exposure to mWD results in greater fold increase with pwWD in saturated lipids and bioactive lipid molecules (i.e. ceramide and sphingomyelin) associated with insulin resistance.


Asunto(s)
Resistencia a la Insulina , Humanos , Animales , Embarazo , Femenino , Adolescente , Resistencia a la Insulina/fisiología , Macaca fuscata/metabolismo , Metabolismo de los Lípidos , Músculo Esquelético/metabolismo , Insulina/metabolismo , Dieta Occidental/efectos adversos , Ácidos Grasos/metabolismo , Ceramidas/metabolismo , Dieta Alta en Grasa
17.
Sci Rep ; 12(1): 15565, 2022 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-36114218

RESUMEN

Geographic atrophy (GA) is a vision-threatening manifestation of age-related macular degeneration (AMD), one of the leading causes of blindness globally. Objective, rapid, reliable, and scalable quantification of GA from optical coherence tomography (OCT) retinal scans is necessary for disease monitoring, prognostic research, and clinical endpoints for therapy development. Such automatically quantified biomarkers on OCT are likely to further elucidate structure-function correlation in GA and thus the pathophysiological mechanisms of disease development and progression. In this work, we aimed to predict visual function with machine-learning applied to automatically acquired quantitative imaging biomarkers in GA. A post-hoc analysis of data from a clinical trial and routine clinical care was conducted. A deep-learning automated segmentation model was applied on OCT scans from 476 eyes (325 patients) with GA. A separate machine learning prediction model (Random Forest) used the resultant quantitative OCT (qOCT) biomarkers to predict cross-sectional visual acuity under standard (VA) and low luminance (LLVA). The primary outcome was regression coefficient (r2) and mean absolute error (MAE) for cross-sectional VA and LLVA in Early Treatment Diabetic Retinopathy Study (ETDRS) letters. OCT parameters were predictive of VA (r2 0.40 MAE 11.7 ETDRS letters) and LLVA (r2 0.25 MAE 12.1). Normalised random forest feature importance, as a measure of the predictive value of the three constituent features of GA; retinal pigment epithelium (RPE)-loss, photoreceptor degeneration (PDR), hypertransmission and their locations, was reported both on voxel-level heatmaps and ETDRS-grid subfields. The foveal region (46.5%) and RPE-loss (31.1%) had greatest predictive importance for VA. For LLVA, however, non-foveal regions (74.5%) and PDR (38.9%) were most important. In conclusion, automated qOCT biomarkers demonstrate predictive significance for VA and LLVA in GA. LLVA is itself predictive of GA progression, implying that the predictive qOCT biomarkers provided by our model are also prognostic.


Asunto(s)
Atrofia Geográfica , Biomarcadores , Estudios Transversales , Atrofia Geográfica/diagnóstico por imagen , Humanos , Aprendizaje Automático , Tomografía de Coherencia Óptica/métodos
18.
Nat Med ; 2(9): 1028-32, 1996 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8782462

RESUMEN

Gene therapy was originally conceived as a medical intervention to replace or correct defective genes in patients with inherited disorders. However, it may have much broader potential as an alternative delivery platform for protein therapeutics, such as cytokines, hormones, antibodies and novel engineered proteins. One key technical barrier to the widespread implementation of this form of therapy is the need for precise control over the level of protein production. A suitable system for pharmacologic control of therapeutic gene expression would permit precise titration of gene product dosage, intermittent or pulsatile treatment, and ready termination of therapy by withdrawal of the activating drug. We set out to design such a system with the following properties: (1) low baseline expression and high induction ratio; (2) positive control by an orally bioavailable small-molecule drug; (3) reduced potential for immune recognition through the exclusive use of human proteins; and (4) modularity to allow the independent optimization of each component using the tools of protein engineering. We report here the properties of this system and demonstrate its use to control circulating levels of human growth hormone in mice implanted with engineered human cells.


Asunto(s)
Regulación de la Expresión Génica/efectos de los fármacos , Hormona del Crecimiento/genética , Inmunofilinas , Inmunosupresores/farmacología , Fosfotransferasas (Aceptor de Grupo Alcohol) , Polienos/farmacología , Animales , Proteínas Portadoras/genética , Proteínas Portadoras/metabolismo , Trasplante de Células , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Terapia Genética , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Humanos , Ratones , Ratones Desnudos , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Sirolimus , Serina-Treonina Quinasas TOR , Proteínas de Unión a Tacrolimus , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Células Tumorales Cultivadas
19.
Brain Res ; 1766: 147540, 2021 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-34052262

RESUMEN

Mutation in proteins containing polyglutamine (polyQ) tracts has been shown to underlie a number of severe human neurodegenerative disorders such as Huntington's Disease and Spinocerebellar Ataxia. In this study, we identify and describe FAM171B as a novel polyQ protein containing fourteen consecutive glutamine residues in its National Center for Biotechnology Information (NCBI) referenced sequence. Utilizing western blotting, in situ hybridization, and immunohistochemistry, we demonstrate that FAM171B is widely expressed in mouse brain with pronounced localization in the hippocampus, cerebellum, and cerebral cortex. Furthermore, immunofluorescence experiments reveal that FAM171B predominantly localizes to vesicle-like structures in the cytoplasm of neurons. Finally, bioinformatic analysis suggests that FAM171B is robustly expressed in human brain, and (similar to other polyQ disease genes) its polyQ tract is polymorphic within the general human population. Thus, as a polyQ protein that is expressed in brain, FAM171B should be considered a candidate gene for an as yet molecularly uncharacterized neurodegenerative disease.


Asunto(s)
Encéfalo/metabolismo , Biología Computacional/métodos , Perfilación de la Expresión Génica/métodos , Proteínas de la Membrana/biosíntesis , Análisis de Secuencia de ARN/métodos , Animales , Expresión Génica , Células HEK293 , Humanos , Masculino , Proteínas de la Membrana/genética , Ratones , Ratones Endogámicos C57BL
20.
Leukemia ; 35(2): 522-533, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-32139889

RESUMEN

Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoma, and front line therapies have not improved overall outcomes since the advent of immunochemotherapy. By pairing DNA and gene expression data with clinical response data, we identified a high-risk subset of non-GCB DLBCL patients characterized by genomic alterations and expression signatures capable of sustaining an inflammatory environment. These mutational alterations (PIM1, SPEN, and MYD88 [L265P]) and expression signatures (NF-κB, IRF4, and JAK-STAT engagement) were associated with proliferative signaling, and were found to be enriched in patients treated with RCHOP that experienced unfavorable outcomes. However, patients with these high-risk mutations had more favorable outcomes when the immunomodulatory agent lenalidomide was added to RCHOP (R2CHOP). We are the first to report the genomic validation of a high-risk phenotype with a preferential response towards R2CHOP therapy in non-GCB DLBCL patients. These conclusions could be translated to a clinical setting to identify the ~38% of non-GCB patients that could be considered high-risk, and would benefit from alternative therapies to standard RCHOP based on personalized genomic data.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Biomarcadores de Tumor/metabolismo , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Linfoma de Células B Grandes Difuso/tratamiento farmacológico , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/genética , Ciclofosfamida/administración & dosificación , Doxorrubicina/administración & dosificación , Femenino , Estudios de Seguimiento , Humanos , Lenalidomida/administración & dosificación , Linfoma de Células B Grandes Difuso/inmunología , Linfoma de Células B Grandes Difuso/patología , Masculino , Persona de Mediana Edad , Prednisona/administración & dosificación , Pronóstico , Estudios Retrospectivos , Rituximab/administración & dosificación , Tasa de Supervivencia , Vincristina/administración & dosificación , Adulto Joven
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