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1.
Br J Pharmacol ; 2024 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-39293936

RESUMO

Three types of highly promising small RNA therapeutics, namely, small interfering RNAs (siRNAs), microRNAs (miRNAs) and the RNA subtype of antisense oligonucleotides (ASOs), offer advantages over small-molecule drugs. These small RNAs can target any gene product, opening up new avenues of effective and safe therapeutic approaches for a wide range of diseases. In preclinical research, synthetic small RNAs play an essential role in the investigation of physiological and pathological pathways as silencers of specific genes, facilitating discovery and validation of drug targets in different conditions. Off-target effects of small RNAs, however, could make it difficult to interpret experimental results in the preclinical phase and may contribute to adverse events of small RNA therapeutics. Out of the two major types of off-target effects we focused on the hybridization-dependent, especially on the miRNA-like off-target effects. Our main aim was to discuss several approaches, including sequence design, chemical modifications and target prediction, to reduce hybridization-dependent off-target effects that should be considered even at the early development phase of small RNA therapy. Because there is no standard way of predicting hybridization-dependent off-target effects, this review provides an overview of all major state-of-the-art computational methods and proposes new approaches, such as the possible inclusion of network theory and artificial intelligence (AI) in the prediction workflows. Case studies and a concise survey of experimental methods for validating in silico predictions are also presented. These methods could contribute to interpret experimental results, to minimize off-target effects and hopefully to avoid off-target-related adverse events of small RNA therapeutics.

2.
Nat Commun ; 15(1): 8220, 2024 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-39300109

RESUMO

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis is a life-threatening autoimmune disease that often results in kidney failure caused by crescentic glomerulonephritis (GN). To date, treatment of most patients with ANCA-GN relies on non-specific immunosuppressive agents, which may have serious adverse effects and be only partially effective. Here, using spatial and single-cell transcriptome analysis, we characterize inflammatory niches in kidney samples from 34 patients with ANCA-GN and identify proinflammatory, cytokine-producing CD4+ and CD8+ T cells as a pathogenic signature. We then utilize these transcriptomic profiles for digital pharmacology and identify ustekinumab, a monoclonal antibody targeting IL-12 and IL-23, as the strongest therapeutic drug to use. Moreover, four patients with relapsing ANCA-GN are treated with ustekinumab in combination with low-dose cyclophosphamide and steroids, with ustekinumab given subcutaneously (90 mg) at weeks 0, 4, 12, and 24. Patients are followed up for 26 weeks to find this treatment well-tolerated and inducing clinical responses, including improved kidney function and Birmingham Vasculitis Activity Score, in all ANCA-GN patients. Our findings thus suggest that targeting of pathogenic T cells in ANCA-GN patients with ustekinumab might represent a potential approach and warrants further investigation in clinical trials.


Assuntos
Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos , Glomerulonefrite , Ustekinumab , Humanos , Ustekinumab/uso terapêutico , Ustekinumab/farmacologia , Glomerulonefrite/tratamento farmacológico , Glomerulonefrite/imunologia , Masculino , Feminino , Pessoa de Meia-Idade , Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/tratamento farmacológico , Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/imunologia , Anticorpos Anticitoplasma de Neutrófilos/imunologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/efeitos dos fármacos , Interleucina-12/metabolismo , Idoso , Adulto , Rim/patologia , Rim/efeitos dos fármacos , Rim/imunologia , Ciclofosfamida/uso terapêutico , Ciclofosfamida/farmacologia , Perfilação da Expressão Gênica , Imunossupressores/uso terapêutico , Imunossupressores/farmacologia , Análise de Célula Única
3.
Evol Lett ; 8(5): 706-718, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39328289

RESUMO

Reciprocal effects of adaptive radiations on the evolution of interspecific interactions, like parasitism, remain barely explored. We test whether the recent radiations of European whitefish (Coregonus spp.) across and within perialpine and subarctic lakes promote its parasite Proteocephalus fallax (Platyhelminthes: Cestoda) to undergo host repertoire expansion via opportunity and ecological fitting, or adaptive radiation by specialization. Using de novo genomic data, we examined P. fallax differentiation across lakes, within lakes across sympatric host species, and the contributions of host genetics versus host habitat use and trophic preferences. Whitefish intralake radiations prompted parasite host repertoire expansion in all lakes, whereas P. fallax differentiation remains incipient among sympatric fish hosts. Whitefish genetic differentiation per se did not explain the genetic differentiation among its parasite populations, ruling out codivergence with the host. Instead, incipient parasite differentiation was driven by whitefish phenotypic radiation in trophic preferences and habitat use in an arena of parasite opportunity and ecological fitting to utilize resources from emerging hosts. Whilst the whitefish radiation provides a substrate for the parasite to differentiate along the same water-depth ecological axis as Coregonus spp., the role of the intermediate hosts in parasite speciation may be overlooked. Parasite multiple-level ecological fitting to both fish and crustacean intermediate hosts resources may be responsible for parasite population substructure in Coregonus spp. We propose parasites' delayed arrival was key to the initial burst of postglacial intralake whitefish diversification, followed by opportunistic tapeworm host repertoire expansion and a delayed nonadaptive radiation cascade of incipient tapeworm differentiation. At the geographical scale, dispersal, founder events, and genetic drift following colonization of spatially heterogeneous landscapes drove strong parasite differentiation. We argue that these microevolutionary processes result in the mirroring of host-parasite phylogenies through phylogenetic tracking at macroevolutionary and geographical scales.

4.
Am J Clin Nutr ; 2024 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-39270936

RESUMO

BACKGROUND: Selenium has potential safeguarding properties against cognitive decline, because of its role in protecting DNA, proteins, and lipids in the brain from oxidative damage. However, acute and chronic overexposure to selenium can be neurotoxic. OBJECTIVE: The aim of this analysis was to explore the association between selenium status [serum selenium and selenoprotein P (SELENOP) concentrations and glutathione peroxidase 3 (GPx3) activity] and cognitive function in 85-y olds living in Northeast England at baseline and ≤5 y of follow-up. METHODS: Global cognitive performance was assessed in 755 participants from the Newcastle 85+ study using the standardized Mini-Mental State Examination and attention-specific cognition was assessed using composite scores derived from the Cognitive Drug Research System. Serum selenium, SELENOP, and GPx3 activity were measured at baseline by total reflection X-ray fluorescence, enzyme-linked immunosorbent assay, and coupled-enzyme reaction, respectively. Regression analyses explored linear and nonlinear associations between continuous values and tertiles of selenium status biomarkers, respectively, and cognitive function at baseline. Generalized linear mixed models explored associations between continuous values and tertiles of selenium status biomarkers, and global cognitive decline over 5 y, and attention-specific cognitive decline over 3 y. RESULTS: Over 3 and 5 y, none of the selenium biomarkers were associated with the rate of cognitive decline. At baseline, in fully adjusted models, higher serum selenium was nonlinearly associated with global cognition (ß = 0.05 ± 0.01, P = 0.387 linear, ß = 0.04 ± 0.01, P = 0.002 nonlinear). SELENOP and GPx3 activity were not associated with any cognitive outcomes. CONCLUSIONS: There were no associations between selenium status and cognitive decline. However, serum selenium, but not SELENOP or GPx3 activity, was positively associated nonlinearly with global cognition at baseline. Furthermore, these associations were not evident during follow-up, potentially because of residual confounding and reverse causation.

5.
Nat Nanotechnol ; 2024 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-39251862

RESUMO

Organoids are transformative in vitro model systems that mimic features of the corresponding tissue in vivo. However, across tissue types and species, organoids still often fail to reach full maturity and function because biochemical cues cannot be provided from within the organoid to guide their development. Here we introduce nanoengineered DNA microbeads with tissue mimetic tunable stiffness for implementing spatio-temporally controlled morphogen gradients inside of organoids at any point in their development. Using medaka retinal organoids and early embryos, we show that DNA microbeads can be integrated into embryos and organoids by microinjection and erased in a non-invasive manner with light. Coupling a recombinant surrogate Wnt to the DNA microbeads, we demonstrate the spatio-temporally controlled morphogen release from the microinjection site, which leads to morphogen gradients resulting in the formation of retinal pigmented epithelium while maintaining neuroretinal cell types. Thus, we bioengineered retinal organoids to more closely mirror the cell type diversity of in vivo retinae. Owing to the facile, one-pot fabrication process, the DNA microbead technology can be adapted to other organoid systems for improved tissue mimicry.

6.
Artigo em Inglês | MEDLINE | ID: mdl-39292408

RESUMO

Right ventricular (RV) strain offers crucial diagnostic insights in cardiovascular and pulmonary disorders. Nonetheless, the absence of established reference values impedes its clinical implementation. Utilizing CMR-feature tracking, age- and gender-dependent RV strains were systematically assessed in 175 heart-healthy Caucasians, 97 females, median 32.5 years. RV global longitudinal strain (GLS) was greater in females than males (median -26.8% (-28.3;-24.1) vs. -24.4 ± 3.0%; p < 0.001), whereby radial and circumferential strain remained comparable. Age subgroups exhibited increased RV-GLS for group B (30-50 years) (-26.0 ± 3.1% vs. -24.4 ± 3.2%; p = 0.011) and group C (> 50 years) (-26.7 ± 2.3% vs. -24.4 ± 3.2%; p < 0.001) compared to group A (< 30 years). High intra-class correlation coefficients (ICC) were exhibited by intrarater variability (ICC = 0.86-0.95) and moderate levels for interrater variability (ICC = 0.50-0.73). CMR-feature tracking provides a fair quantification method of age- and gender-specific normal RV strain values, demonstrating that higher RV-GLS is linked to female gender and advancing age within a healthy Caucasian cohort.

7.
Sci Rep ; 14(1): 20989, 2024 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-39251776

RESUMO

Heteroplasmic mitochondrial DNA (mtDNA) variants accumulate as humans age, particularly in the stem-cell compartments, and are an important contributor to age-related disease. Mitochondrial dysfunction has been observed in osteoporosis and somatic mtDNA pathogenic variants have been observed in animal models of osteoporosis. However, this has never been assessed in the relevant human tissue. Mesenchymal stem cells (MSCs) are the progenitors to many cells of the musculoskeletal system and are critical to skeletal tissues and bone vitality. Investigating mtDNA in MSCs could provide novel insights into the role of mitochondrial dysfunction in osteoporosis. To determine if this is possible, we investigated the landscape of somatic mtDNA variation in MSCs through a combination of fluorescence-activated cell sorting and single-cell next-generation sequencing. Our data show that somatic heteroplasmic variants are present in individual patient-derived MSCs, can reach high heteroplasmic fractions and have the potential to be pathogenic. The identification of somatic heteroplasmic variants in MSCs of patients highlights the potential for mitochondrial dysfunction to contribute to the pathogenesis of osteoporosis.


Assuntos
DNA Mitocondrial , Células-Tronco Mesenquimais , Humanos , Células-Tronco Mesenquimais/metabolismo , DNA Mitocondrial/genética , Osteoporose/genética , Osteoporose/patologia , Osteoporose/metabolismo , Mitocôndrias/metabolismo , Mitocôndrias/genética , Análise de Célula Única , Sequenciamento de Nucleotídeos em Larga Escala , Feminino , Heteroplasmia/genética , Masculino , Citometria de Fluxo , Variação Genética , Pessoa de Meia-Idade
8.
JACC Adv ; 3(10): 101191, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39290810

RESUMO

The Heart Valve Collaboratory is a multidisciplinary, patient-centered community of stakeholders addressing complex problems and embracing innovation to help patients with heart valve disease achieve their fullest potential for health. The Scientific Council is composed of cardiologists, surgeons, ex-officio representatives of the Food and Drug Administration and Centers for Medicare and Medicaid Services, National Heart Lung Blood Institute, and representatives from industry partners. In October 2022, this group convened a workshop that included experts from stakeholder groups to address the unmet and clinical needs of patients with pediatric and congenital heart valve disease. The following document includes the discussion and summary of the current state of valve therapy and the needs being addressed for valve development.

9.
Cell Rep ; 43(9): 114704, 2024 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-39216000

RESUMO

T cell activation is governed through T cell receptors (TCRs), heterodimers of two sequence-variable chains (often an α and ß chain) that synergistically recognize antigen fragments presented on cell surfaces. Despite this, there only exist repositories dedicated to collecting single-chain, not paired-chain, TCR sequence data. We addressed this gap by creating the Observed TCR Space (OTS) database, a source of consistently processed and annotated, full-length, paired-chain TCR sequences. Currently, OTS contains 5.35 million redundant (1.63 million non-redundant), predominantly human sequences from across 50 studies and at least 75 individuals. Using OTS, we identify pairing biases, public TCRs, and distinct chain coherence patterns relative to antibodies. We also release a paired-chain TCR language model, providing paired embedding representations and a method for residue in-filling conditional on the partner chain. OTS will be updated as a central community resource and is freely downloadable and available as a web application.


Assuntos
Receptores de Antígenos de Linfócitos T , Humanos , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores de Antígenos de Linfócitos T/imunologia , Mineração de Dados/métodos
10.
Schizophr Bull Open ; 5(1): sgae008, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-39144116

RESUMO

Background and Hypothesis: Studies have linked auditory hallucinations (AH) in schizophrenia spectrum disorders (SCZ) to altered cerebral white matter microstructure within the language and auditory processing circuitry (LAPC). However, the specificity to the LAPC remains unclear. Here, we investigated the relationship between AH and DTI among patients with SCZ using diffusion tensor imaging (DTI). Study Design: We included patients with SCZ with (AH+; n = 59) and without (AH-; n = 81) current AH, and 140 age- and sex-matched controls. Fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (AD) were extracted from 39 fiber tracts. We used principal component analysis (PCA) to identify general factors of variation across fiber tracts and DTI metrics. Regression models adjusted for sex, age, and age2 were used to compare tract-wise DTI metrics and PCA factors between AH+, AH-, and healthy controls and to assess associations with clinical characteristics. Study Results: Widespread differences relative to controls were observed for MD and RD in patients without current AH. Only limited differences in 2 fiber tracts were observed between AH+ and controls. Unimodal PCA factors based on MD, RD, and AD, as well as multimodal PCA factors, differed significantly relative to controls for AH-, but not AH+. We did not find any significant associations between PCA factors and clinical characteristics. Conclusions: Contrary to previous studies, DTI metrics differed mainly in patients without current AH compared to controls, indicating a widespread neuroanatomical distribution. This challenges the notion that altered DTI metrics within the LAPC is a specific feature underlying AH.

11.
Perit Dial Int ; : 8968608241270294, 2024 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-39105257

RESUMO

Automation has allowed clinicians to program PD treatment parameters, all while obtaining extensive individual treatment data. This data populates in a centralized online platform shortly after PD treatment completion. Individual treatment data available to providers includes patients' vital signs, alarms, bypasses, prescribed PD treatment, actual treatment length, individual cycle fill volumes, ultrafiltration volumes, as well as fill, dwell, and drain times. However, there is no guidance about how often or if this data should be assessed by the clinical team members. We set out to determine current practice patterns by surveying members of the home dialysis team managing PD patients across the United States and Canada. A total of 127 providers completed the survey. While 91% of respondents reported having access to a remote monitoring platform, only 31% reported having a standardized protocol for data monitoring. Rating their perceived importance of having a standard protocol for remote data monitoring, on a scale of 0 (not important at all) to 10 (extremely important), the average response was 8 (physicians 7; nurses 9). Most nurses reported reviewing the data multiple times per week, whereas most physicians reported viewing the data only during regular/monthly visits. Although most of the providers who responded have access to remote monitoring data and feel that regular review is important, the degree of its utilization is variable, and the way in which the information is used is not commonly protocolized. Working to standardize data interpretation, testing algorithms, and educating providers to help process and present the data are important next steps.

12.
Cancer Res ; 2024 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-39186615

RESUMO

Changes in the composition and physical properties of the tumor extracellular matrix are linked to poor cytotoxic T-cell infiltration and therapy response, yet the underlying mechanisms remain unclear. Tharp and colleagues revealed a fascinating cascade where tumor fibrosis alters macrophage metabolism, restricting the nutrients available to infiltrating T-cells and resulting in their suppression and exclusion from the tumor microenvironment. This study suggests that targeting metabolic pathways could be a promising strategy to overcome the immune suppression induced by the tumor extracellular matrix.

13.
Int J Gynecol Cancer ; 34(9): 1313-1321, 2024 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-39153831

RESUMO

OBJECTIVE: Management of endometrial cancer is advancing, with accurate staging crucial for guiding treatment decisions. Understanding sentinel lymph node (SLN) involvement rates across molecular subgroups is essential. To evaluate SLN involvement in early-stage (International Federation of Gynecology and Obstetrics 2009 I-II) endometrial cancer, considering molecular subtypes and new European Society of Gynaecological Oncology (ESGO) risk classification. METHODS: The SENECA study retrospectively reviewed data from 2139 women with stage I-II endometrial cancer across 66 centers in 16 countries. Patients underwent surgery with SLN assessment following ESGO guidelines between January 2021 and December 2022. Molecular analysis was performed on pre-operative biopsies or hysterectomy specimens. RESULTS: Among the 2139 patients, the molecular subgroups were as follows: 272 (12.7%) p53 abnormal (p53abn, 1191 (55.7%) non-specific molecular profile (NSMP), 581 (27.2%) mismatch repair deficient (MMRd), 95 (4.4%) POLE mutated (POLE-mut). Tracer diffusion was detected in, at least one side, in 97.2% of the cases; with a bilateral diffusion observed in 82.7% of the cases. By ultrastaging (90.7% of the cases) or one-step nucleic acid amplification (198 (9.3%) of the cases), 205 patients were identified with affected sentinel lymph nodes, representing 9.6% of the sample. Of these, 139 (67.8%) had low-volume metastases (including micrometastases, 42.9%; and isolated tumor cells, 24.9%) while 66 (32.2%) had macrometastases. Significant differences in SLN involvement were observed between molecular subtypes, with p53abn and MMRd groups having the highest rates (12.50% and 12.40%, respectively) compared with NSMP (7.80%) and POLE-mut (6.30%), (p=0.004); (p53abn, OR=1.69 (95% CI 1.11 to 2.56), p=0.014; MMRd, OR=1.67 (95% CI 1.21 to 2.31), p=0.002). Differences were also noted among ESGO risk groups (2.84% for low-risk patients, 6.62% for intermediate-risk patients, 21.63% for high-intermediate risk patients, and 22.51% for high-risk patients; p<0.001). CONCLUSIONS: Our study reveals significant differences in SLN involvement among patients with early-stage endometrial cancer based on molecular subtypes. This underscores the importance of considering molecular characteristics for accurate staging and optimal management decisions.


Assuntos
Neoplasias do Endométrio , Estadiamento de Neoplasias , Humanos , Feminino , Neoplasias do Endométrio/patologia , Neoplasias do Endométrio/genética , Neoplasias do Endométrio/classificação , Estudos Retrospectivos , Pessoa de Meia-Idade , Idoso , Linfonodo Sentinela/patologia , Idoso de 80 Anos ou mais , Adulto , Biópsia de Linfonodo Sentinela/métodos , Metástase Linfática
14.
ACS Meas Sci Au ; 4(4): 338-417, 2024 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-39193565

RESUMO

Proteomics is the large scale study of protein structure and function from biological systems through protein identification and quantification. "Shotgun proteomics" or "bottom-up proteomics" is the prevailing strategy, in which proteins are hydrolyzed into peptides that are analyzed by mass spectrometry. Proteomics studies can be applied to diverse studies ranging from simple protein identification to studies of proteoforms, protein-protein interactions, protein structural alterations, absolute and relative protein quantification, post-translational modifications, and protein stability. To enable this range of different experiments, there are diverse strategies for proteome analysis. The nuances of how proteomic workflows differ may be challenging to understand for new practitioners. Here, we provide a comprehensive overview of different proteomics methods. We cover from biochemistry basics and protein extraction to biological interpretation and orthogonal validation. We expect this Review will serve as a handbook for researchers who are new to the field of bottom-up proteomics.

15.
Obes Rev ; 25(10): e13803, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39096049

RESUMO

This umbrella review assessed the association between excess weight and COVID-19 outcomes. MEDLINE, PsycINFO, and CINAHL were systematically searched for reviews that assessed the association between excess weight and COVID-19 outcomes. A second-order meta-analysis was conducted on the available data for intensive care unit admission, invasive mechanical ventilation administration, disease severity, hospitalization, and mortality. The quality of included reviews was assessed using the AMSTAR-2 appraisal tool. In total, 52 systematic reviews were included, 49 of which included meta-analyses. The risk of severe outcomes (OR = 1.86; 95% CI: 1.70 to 2.05), intensive care unit admission (OR = 1.58; 95% CI: 1.45 to 1.72), invasive mechanical ventilation administration (OR = 1.70; 95% CI: 1.57 to 1.83), hospitalization (OR = 1.82; 95% CI: 1.61 to 2.05), and mortality (OR = 1.35; 95% CI: 1.24 to 1.48) following COVID-19 infection was significantly higher in individuals living with excess weight compared with those with a healthy weight. There was limited evidence available in the included reviews regarding the influence of moderating factors such as ethnicity, and the majority of included reviews were of poor quality. Obesity appears to represent an important modifiable pre-infection risk factor for severe COVID-19 outcomes, including death.


Assuntos
COVID-19 , Obesidade , Humanos , COVID-19/mortalidade , Hospitalização/estatística & dados numéricos , Unidades de Terapia Intensiva , Obesidade/complicações , Sobrepeso , Respiração Artificial/estatística & dados numéricos , Fatores de Risco , SARS-CoV-2
16.
Burns ; 2024 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-39181766

RESUMO

BACKGROUND: Early retrospective data identify that dysphagia is common in older persons with burn injury, suggesting a rate of 47 %, and that it is associated with medical, burn, and nutritional outcomes. AIMS: To prospectively (1) explore the incidence, (2) describe associations, and (3) evaluate risk factors for dysphagia in patients ≥ 75 years old hospitalised with burn injury. METHODS: All patients > 75 years old admitted to Concord-Repatriation-General-Hospital with burn injury over 4 years (2019-2023) were assessed for dysphagia on presentation and were continually monitored throughout their admission. Burn injury, demographic, and nutritional data were prospectively captured and analysed for association with dysphagia. RESULTS: Sixty-two patients (33 male) aged 75-95 years (median=83 years) were recruited. Dysphagia was identified in 50 %. Dysphagia was associated with burn size (p = 0.002), pre-existing cognitive impairment (p = 0.000), hospital length of stay (p = 0.001), in-hospital complications (p = 0.000), feeding dependence (p = 0.002), nutritional status (p = 0.013) and enteral feeding duration (p = 0.030). Cognitive impairment was the most sensitive predictor for dysphagia at 100 % (specificity=29 %, NPV=100 %, PPV=59 %). Development of secondary comorbidities was less sensitive at 52 % (NPV 65 %), but was associated with high specificity (90 %) and PPV (84 %). CONCLUSIONS: One in every two patients ≥ 75 years admitted with burn injury will demonstrate dysphagia during their hospital admission. Those with pre-existing cognitive impairment are most at risk.

17.
J Am Soc Mass Spectrom ; 35(8): 1976-1990, 2024 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-39037040

RESUMO

The onset and progression of cancer is associated with changes in the composition of the lipidome. Therefore, better understanding of the molecular mechanisms of these disease states requires detailed structural characterization of the individual lipids within the complex cellular milieu. Recently, changes in the unsaturation profile of membrane lipids have been observed in cancer cells and tissues, but assigning the position(s) of carbon-carbon double bonds in fatty acyl chains carried by membrane phospholipids, including the resolution of lipid regioisomers, has proven analytically challenging. Conventional tandem mass spectrometry approaches based on collision-induced dissociation of ionized glycerophospholipids do not yield spectra that are indicative of the location(s) of carbon-carbon double bonds. Ozone-induced dissociation (OzID) and ultraviolet photodissociation (UVPD) have emerged as alternative ion activation modalities wherein diagnostic product ions can enable de novo assignment of position(s) of unsaturation based on predictable fragmentation behaviors. Here, for the first time, OzID and UVPD (193 nm) mass spectra are acquired on the same mass spectrometer to evaluate the relative performance of the two modalities for lipid identification and to interrogate the respective fragmentation pathways under comparable conditions. Based on investigations of lipid standards, fragmentation rules for each technique are expanded to increase confidence in structural assignments and exclude potential false positives. Parallel application of both methods to unsaturated phosphatidylcholines extracted from isogenic colorectal cancer cell lines provides high confidence in the assignment of multiple double bond isomers in these samples and cross-validates relative changes in isomer abundance.


Assuntos
Ozônio , Humanos , Ozônio/química , Lipídeos/química , Lipídeos/análise , Raios Ultravioleta , Espectrometria de Massas/métodos , Espectrometria de Massas em Tandem/métodos , Linhagem Celular Tumoral , Íons/química
18.
J Mol Cell Cardiol ; 194: 85-95, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38960317

RESUMO

Coronary heart disease (CHD) is a prevalent cardiac disease that causes over 370,000 deaths annually in the USA. In CHD, occlusion of a coronary artery causes ischemia of the cardiac muscle, which results in myocardial infarction (MI). Junctophilin-2 (JPH2) is a membrane protein that ensures efficient calcium handling and proper excitation-contraction coupling. Studies have identified loss of JPH2 due to calpain-mediated proteolysis as a key pathogenic event in ischemia-induced heart failure (HF). Our findings show that calpain-2-mediated JPH2 cleavage yields increased levels of a C-terminal cleaved peptide (JPH2-CTP) in patients with ischemic cardiomyopathy and mice with experimental MI. We created a novel knock-in mouse model by removing residues 479-SPAGTPPQ-486 to prevent calpain-2-mediated cleavage at this site. Functional and molecular assessment of cardiac function post-MI in cleavage site deletion (CSD) mice showed preserved cardiac contractility and reduced dilation, reduced JPH2-CTP levels, attenuated adverse remodeling, improved T-tubular structure, and normalized SR Ca2+-handling. Adenovirus mediated calpain-2 knockdown in mice exhibited similar findings. Pulldown of CTP followed by proteomic analysis revealed valosin-containing protein (VCP) and BAG family molecular chaperone regulator 3 (BAG3) as novel binding partners of JPH2. Together, our findings suggest that blocking calpain-2-mediated JPH2 cleavage may be a promising new strategy for delaying the development of HF following MI.


Assuntos
Calpaína , Insuficiência Cardíaca , Proteínas de Membrana , Infarto do Miocárdio , Animais , Humanos , Masculino , Camundongos , Calpaína/metabolismo , Modelos Animais de Doenças , Progressão da Doença , Insuficiência Cardíaca/metabolismo , Insuficiência Cardíaca/etiologia , Proteínas de Membrana/metabolismo , Proteínas de Membrana/genética , Proteínas Musculares , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/patologia , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/patologia , Proteólise
19.
Sleep Adv ; 5(1): zpae035, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38966620

RESUMO

This perspective on alternatives to positive airway pressure (PAP) therapy for the treatment of obstructive sleep apnea (OSA) summarizes the proceedings of a focus group that was conducted by the Sleep Research Society Foundation. This perspective is from a multidisciplinary panel of experts from sleep medicine, dental sleep medicine, and otolaryngology that aims to identify the current role of oral appliance therapy and hypoglossal nerve stimulation for the treatment of OSA with emphasis on the US practice arena. A secondary aim is to identify-from an implementation science standpoint-the various barriers and facilitators for adoption of non-PAP treatment that includes access to care, multidisciplinary expertise, reimbursement, regulatory aspects, current treatment guidelines, health policies, and other factors related to the delivery of care. The panel has contextualized the review with recent events-such as a large-scale PAP device recall compounded by supply chain woes of the pandemic-and emerging science in the field of OSA and offers solutions for multidisciplinary approaches while identifying knowledge gaps and future research opportunities.

20.
New Phytol ; 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-39001592

RESUMO

Polysaccharide structural complexity not only influences cell wall strength and extensibility but also hinders pathogenic and biotechnological attempts to saccharify the wall. In certain species and tissues, glucuronic acid side groups on xylan exhibit arabinopyranose or galactose decorations whose genetic and evolutionary basis is completely unknown, impeding efforts to understand their function and engineer wall digestibility. Genetics and polysaccharide profiling were used to identify the responsible loci in Arabidopsis and Eucalyptus from proposed candidates, while phylogenies uncovered a shared evolutionary origin. GH30-family endo-glucuronoxylanase activities were analysed by electrophoresis, and their differing specificities were rationalised by phylogeny and structural analysis. The newly identified xylan arabinopyranosyltransferases comprise an overlooked subfamily in the GT47-A family of Golgi glycosyltransferases, previously assumed to comprise mainly xyloglucan galactosyltransferases, highlighting an unanticipated adaptation of both donor and acceptor specificities. Further neofunctionalisation has produced a Myrtaceae-specific xylan galactosyltransferase. Simultaneously, GH30 endo-glucuronoxylanases have convergently adapted to overcome these decorations, suggesting a role for these structures in defence. The differential expression of glucuronoxylan-modifying genes across Eucalyptus tissues, however, hints at further functions. Our results demonstrate the rapid adaptability of biosynthetic and degradative carbohydrate-active enzyme activities, providing insight into plant-pathogen interactions and facilitating plant cell wall biotechnological utilisation.

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