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Found 37769 matches. Displaying 441-450
Chen YJ, Iyer SV, Hsieh DCC, Li BR, Elias HK, Wang T, Li J, Ganbold M, Lien M...
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Gliocidin is a nicotinamide-mimetic prodrug that targets glioblastoma

NATURE 2024 DEC 12; 636(8042):466-+
Glioblastoma is incurable and in urgent need of improved therapeutics(1). Here we identify a small compound, gliocidin, that kills glioblastoma cells while sparing non-tumour replicative cells. Gliocidin activity targets a de novo purine synthesis vulnerability in glioblastoma through indirect inhibition of inosine monophosphate dehydrogenase 2 (IMPDH2). IMPDH2 blockade reduces intracellular guanine nucleotide levels, causing nucleotide imbalance, replication stress and tumour cell death(2). Gliocidin is a prodrug that is anabolized into its tumoricidal metabolite, gliocidin-adenine dinucleotide (GAD), by the enzyme nicotinamide nucleotide adenylyltransferase 1 (NMNAT1) of the NAD(+) salvage pathway. The cryo-electron microscopy structure of GAD together with IMPDH2 demonstrates its entry, deformation and blockade of the NAD(+) pocket(3). In vivo, gliocidin penetrates the blood-brain barrier and extends the survival of mice with orthotopic glioblastoma. The DNA alkylating agent temozolomide induces Nmnat1 expression, causing synergistic tumour cell killing and additional survival benefit in orthotopic patient-derived xenograft models. This study brings gliocidin to light as a prodrug with the potential to improve the survival of patients with glioblastoma.
Fedeli SB, Leibler S
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Toward systems agroecology: Design and control of intercropping

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 2024 DEC 24; 121(52):? Article e2415315121
In view of changing climatic conditions and disappearing natural resources such as fertile soil and water, exploring alternatives to today's industrial monocrop farming becomes essential. One promising farming practice is intercropping (IC), in which two or more crop species are grown together. Many experiments have shown that, under certain circumstances, IC can decrease soil erosion and fertilizer use, improve soil health and land management, while preserving crop production levels. However, there have been no quantitative approaches to predict, design, and control appropriate IC implementation for given particular environmental and farming conditions, and to assess its robustness. Here, we develop such an approach, based on methods and concepts developed in data science and systems biology. Our dataset groups the results of 2258 IC experiments, involving 274 pairs of 69 different plants. The data include 4 soil characteristics and 5 environmental and farming conditions, together with 8 traits for each of the two intercropped plants. We performed a dimensional reduction of the resulting 25-dimensional variable space and showed that, from a few quantities, one can predict IC yield relative to sole cultivation with good accuracy. For given environmental conditions, our computational approach can help to choose a companion plant and appropriate farming practices. It also indicates how to estimate the robustness of IC to external perturbations. This approach, together with its results, can be viewed as an initial step toward "systems agriculture," which would ultimately develop systems of multiple plant grown together in appropriately designed and controlled settings.
Yu WW, Barrett JNP, Tong J, Lin MJ, Marohn M, Devlin JC, Herrera A, Remark J,...
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Skin immune-mesenchymal interplay within tertiarylymphoid structures promotes...

IMMUNITY 2024 DEC 10; 57(12):?
Hidradenitis suppurativa (HS) is a chronic, debilitating inflammatory skin disease characterized by keratinized epithelial tunnels that grow deeply into the dermis. Here, we examined the immune microenvironment within human HS lesions. Multi-omics profiling and multiplexed imaging identified tertiary lymphoid structures (TLSs) near HS tunnels. These TLSs were enriched with proliferative T cells, including follicular helper (Tfh), regulatory (Treg), and pathogenic T cells ( IL17A + and IFNG +), alongside extensive clonal expansion of plasma cells producing antibodies reactive to keratinocytes. HS fibroblasts express CXCL13 or CCL19 in response to immune cytokines. Using a microfluidic system to mimic TLS on a chip, we found that HS fibroblasts critically orchestrated lymphocyte aggregation via tumor necrosis factor alpha (TNF-a)-CXCL13 and TNF-a-CCL19 feedback loops with B and T cells, respectively; early TNF-a blockade suppressed aggregate initiation. Our findings provide insights into TLS formation in the skin, suggest therapeutic avenues for HS, and reveal mechanisms that may apply to other autoimmune settings, including Crohn's disease.
Bruno J, Walker JM, Nasserifar S, Upadhyay D, Ronning A, Vanegas SM, Popp CJ,...
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Weight-neutral early time-restricted eating improves glycemic variation and t...

ISCIENCE 2024 DEC 20; 27(12):? Article 111501
Early time-restricted eating (eTRE) is a dietary strategy that restricts caloric intake to the first 6-8 h of the day and can effect metabolic benefits independent of weight loss. However, the extent of these benefits is unknown. We conducted a randomized crossover feeding study to investigate the weight-independent effects of eTRE on glycemic variation, multiple time-in-range metrics, and levels of inflammatory markers. Ten adults with prediabetes were randomized to eTRE (8-h feeding window, 80% of calories consumed before 14:00 h) or usual feeding (50% of calories consumed after 16:00 h) for 1 week followed by crossover to the other schedule. Using continuous glucose monitoring, we showed that eTRE decreased glycemic variation (mean amplitude of glycemic excursion) and time in hyperglycemia greater than 140 mg/dL without affecting inflammatory markers (erythrocyte sedimentation rate and C-reactive protein). These data implicate eTRE as a candidate dietary intervention for the weight-independent management of dysglycemia in high-risk individuals.
Cunningham-Rundles C, Casanova JL, Boisson B
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Common variable immunodeficiency: auto im mune cytopenias and advances in mol...

HEMATOLOGY-AMERICAN SOCIETY OF HEMATOLOGY EDUCATION PROGRAM 2024 DEC 6; ?(1):137-142
Common variable immunodeficiency (CVID) is one of the most common groups of human inborn errors of immunity. In addition to infections resulting from insufficient levels of immunoglobulins and antibodies, a signifi cant proportion of patients develop autoimmune cytopenias, especially immune thrombocytopenia, hemolytic anemia, or neutropenia. They may be the initial manifestation of CVID in a patient who has not had significant infections, and similar episodes may recur at intervals over time. Treatment of these hematologic complications includes the use of corticosteroids or other medications, often including rituximab; splenectomy is discouraged. Here we outline the overall occurrence of these blood cytopenias in a cohort of 408 patients, as well as the clinical and genetic associations noted in these individuals.
Ru S, Tang SS, Xu H, Yin JH, Guo Y, Song LP, Jin ZY, Lee DY, Chan YH, Chen XY...
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Human DBR1 deficiency impairs stress granule-dependent PKR antiviral immunity

JOURNAL OF EXPERIMENTAL MEDICINE 2024 DEC 5; 222(1):? Article e20240010
The molecular mechanism by which inborn errors of the human RNA lariat-debranching enzyme 1 (DBR1) underlie brainstem viral encephalitis is unknown. We show here that the accumulation of RNA lariats in human DBR1-deficient cells interferes with stress granule (SG) assembly, promoting the proteasome degradation of at least G3BP1 and G3BP2, two key components of SGs. In turn, impaired assembly of SGs, which normally recruit PKR, impairs PKR activation and activity against viruses, including HSV-1. Remarkably, the genetic ablation of PKR abolishes the corresponding antiviral effect of DBR1 in vitro. We also show that Dbr1Y17H/Y17H mice are susceptible to similar viral infections in vivo. Moreover, cells and brain samples from Dbr1Y17H/Y17H mice exhibit decreased G3BP1/2 expression and PKR phosphorylation. Thus, the debranching of RNA lariats by DBR1 permits G3BP1/2- and SG assembly-mediated PKR activation and cell-intrinsic antiviral immunity in mice and humans. DBR1-deficient patients are prone to viral disease because of intracellular lariat accumulation, which impairs G3BP1/2- and SG assembly-dependent PKR activation.
Bohn JA, Meagher JL, Takata MA, Gonçalves-Carneiro D, Yeoh ZC, Ohi MD, Smith ...
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Functional anatomy of zinc finger antiviral protein complexes

NATURE COMMUNICATIONS 2024 DEC 30; 15(1):? Article 10834
ZAP is an antiviral protein that binds to and depletes viral RNA, which is often distinguished from vertebrate host RNA by its elevated CpG content. Two ZAP cofactors, TRIM25 and KHNYN, have activities that are poorly understood. Here, we show that functional interactions between ZAP, TRIM25 and KHNYN involve multiple domains of each protein, and that the ability of TRIM25 to multimerize via its RING domain augments ZAP activity and specificity. We show that KHNYN is an active nuclease that acts in a partly redundant manner with its homolog N4BP1. The ZAP N-terminal RNA binding domain constitutes a minimal core that is essential for antiviral complex activity, and we present a crystal structure of this domain that reveals contacts with the functionally required KHNYN C-terminal domain. These contacts are remote from the ZAP CpG binding site and would not interfere with RNA binding. Based on our dissection of ZAP, TRIM25 and KHNYN functional anatomy, we could design artificial chimeric antiviral proteins that reconstitute the antiviral function of the intact authentic proteins, but in the absence of protein domains that are otherwise required for activity. Together, these results suggest a model for the RNA recognition and action of ZAP-containing antiviral protein complexes.
Glines MR, Amancio RCH, Andersen MR, Baulch H, Brighenti LS, Chmiel HE, Cohen...
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Coefficients in Taylor's law increase with the time scale of water clarity me...

ECOLOGY LETTERS 2024 DEC; 27(12):? Article e14451
Identifying the scaling rules describing ecological patterns across time and space is a central challenge in ecology. Taylor's law of fluctuation scaling, which states that the variance of a population's size or density is proportional to a positive power of the mean size or density, has been widely observed in population dynamics and characterizes variability in multiple scientific domains. However, it is unclear if this phenomenon accurately describes ecological patterns across many orders of magnitude in time, and therefore links otherwise disparate observations. Here, we use water clarity observations from 10,531 days of high-frequency measurements in 35 globally distributed lakes, and lower-frequency measurements over multiple decades from 6342 lakes to test this unknown. We focus on water clarity as an integrative ecological characteristic that responds to both biotic and abiotic drivers. We provide the first documentation that variations in ecological measurements across diverse sites and temporal scales exhibit variance patterns consistent with Taylor's law, and that model coefficients increase in a predictable yet non-linear manner with decreasing observation frequency. This discovery effectively links high-frequency sensor network observations with long-term historical monitoring records, thereby affording new opportunities to understand and predict ecological dynamics on time scales from days to decades.
Clark JJ, Hoxie I, Adelsberg DC, Sapse IA, Andreata-Santos R, Yong JS, Amanat...
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Protective effect and molecular mechanisms of human non-neutralizing cross-re...

CELL REPORTS 2024 NOV 26; 43(11):? Article 114922
Neutralizing antibodies correlate with protection against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Recent studies, however, show that binding antibody titers, in the absence of robust neutralizing activity, also correlate with protection against disease progression. Non-neutralizing antibodies cannot directly protect against infection but may recruit effector cells and thus contribute to the clearance of infected cells. Additionally, they often bind conserved epitopes across multiple variants. Here, we characterize 42 human monoclonal antibodies (mAbs) from coronavirus disease 2019 (COVID-19)-vaccinated individuals. Most of these antibodies exhibit no neutralizing activity in vitro, but several non-neutralizing antibodies provide protection against lethal challenge with SARS-CoV-2 in different animal models. A subset of those mAbs shows a clear dependence on Fc-mediated effector functions. We have determined the structures of three non-neutralizing antibodies, with two targeting the receptor-binding domain and one that binds the subdomain 1 region. Our data confirm the real-world observation in humans that non-neutralizing antibodies to SARS-CoV-2 can be protective.
Sbruzzi RC, Prado MJ, Fam B, Prolla HA, Hellwig A, Rodrigues GM, de-Paris F, ...
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Case report: A novel JAK3 homozygous variant in a patient with severe ...

FRONTIERS IN IMMUNOLOGY 2024 NOV 13; 15(?):? Article 1472957
Inborn errors of immunity (IEI) encompass a broad range of disorders with heterogeneous clinical presentations, often leading to challenges in early diagnosis. This study presents a case of a Brazilian patient with a T-B+NK- severe combined immunodeficiency (SCID) diagnosed at the age of 6 months when was admitted to the hospital due to multiple infectious diseases. Despite undergoing hematopoietic stem cell transplantation (HSCT), the patient had recurrent infections, requiring constant hospital care, including IgG infusions and several antibiotic treatments for the following months. One year after HSCT, presenting mixed chimerism, the patient tested positive for SARS-CoV-2 in nasopharyngeal, duodenum, and intestine samples, with persistent positive tests over a six-month period. Whole exome sequencing identified a private homozygous missense variant (c.1202T>C; p.Leu401Pro) in the Janus Kinase 3 (JAK3) gene. This substitution is located in a highly conserved position, and different bioinformatic variant effect predictors classified the variant as damaging. In silico structural analysis suggested that the variant led to increased structural instability, disrupting the hydrophobic interactions within the SH2 domain, thereby influencing the neighboring residues and potentially altering the interaction between JAK3 and gamma chain (gamma c) intracellular receptors. This study provides evidence for the novel pathogenicity classification of the variant and highlights the importance of the JAK3 and SH2 domain modulating protein function and their contribution to the SCID pathogenesis.