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1.
Brief Bioinform ; 24(6)2023 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-37985452

RESUMO

Charting microRNA (miRNA) regulation across pathways is key to characterizing their function. Yet, no method currently exists that can quantify how miRNAs regulate multiple interconnected pathways or prioritize them for their ability to regulate coordinate transcriptional programs. Existing methods primarily infer one-to-one relationships between miRNAs and pathways using differentially expressed genes. We introduce PanomiR, an in silico framework for studying the interplay of miRNAs and disease functions. PanomiR integrates gene expression, mRNA-miRNA interactions and known biological pathways to reveal coordinated multi-pathway targeting by miRNAs. PanomiR utilizes pathway-activity profiling approaches, a pathway co-expression network and network clustering algorithms to prioritize miRNAs that target broad-scale transcriptional disease phenotypes. It directly resolves differential regulation of pathways, irrespective of their differential gene expression, and captures co-activity to establish functional pathway groupings and the miRNAs that may regulate them. PanomiR uses a systems biology approach to provide broad but precise insights into miRNA-regulated functional programs. It is available at https://bioconductor.org/packages/PanomiR.


Assuntos
MicroRNAs , MicroRNAs/metabolismo , Biologia de Sistemas , Perfilação da Expressão Gênica/métodos , Biologia Computacional/métodos , Redes Reguladoras de Genes
2.
Mol Psychiatry ; 2024 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-39266711

RESUMO

The psychosis spectrum encompasses a heterogeneous range of clinical conditions associated with abnormal brain development. Detecting patterns of atypical neuroanatomical maturation across psychiatric disorders requires an interpretable metric standardized by age-, sex- and site-effect. The molecular and micro-architectural attributes that account for these deviations in brain structure from typical neurodevelopment are still unknown. Here, we aggregate structural magnetic resonance imaging data from 38,696 healthy controls (HC) and 1256 psychosis-related conditions, including first-degree relatives of schizophrenia (SCZ) and schizoaffective disorder (SAD) patients (n = 160), individuals who had psychotic experiences (n = 157), patients who experienced a first episode of psychosis (FEP, n = 352), and individuals with chronic SCZ or SAD (n = 587). Using a normative modeling approach, we generated centile scores for cortical gray matter (GM) phenotypes, identifying deviations in regional volumes below the expected trajectory for all conditions, with a greater impact on the clinically diagnosed ones, FEP and chronic. Additionally, we mapped 46 neurobiological features from healthy individuals (including neurotransmitters, cell types, layer thickness, microstructure, cortical expansion, and metabolism) to these abnormal centiles using a multivariate approach. Results revealed that neurobiological features were highly co-localized with centile deviations, where metabolism (e.g., cerebral metabolic rate of oxygen (CMRGlu) and cerebral blood flow (CBF)) and neurotransmitter concentrations (e.g., serotonin (5-HT) and acetylcholine (α4ß2) receptors) showed the most consistent spatial overlap with abnormal GM trajectories. Taken together these findings shed light on the vulnerability factors that may underlie atypical brain maturation during different stages of psychosis.

3.
Nucleic Acids Res ; 51(D1): D9-D17, 2023 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-36477213

RESUMO

The European Molecular Biology Laboratory's European Bioinformatics Institute (EMBL-EBI) is one of the world's leading sources of public biomolecular data. Based at the Wellcome Genome Campus in Hinxton, UK, EMBL-EBI is one of six sites of the European Molecular Biology Laboratory (EMBL), Europe's only intergovernmental life sciences organisation. This overview summarises the status of services that EMBL-EBI data resources provide to scientific communities globally. The scale, openness, rich metadata and extensive curation of EMBL-EBI added-value databases makes them particularly well-suited as training sets for deep learning, machine learning and artificial intelligence applications, a selection of which are described here. The data resources at EMBL-EBI can catalyse such developments because they offer sustainable, high-quality data, collected in some cases over decades and made openly availability to any researcher, globally. Our aim is for EMBL-EBI data resources to keep providing the foundations for tools and research insights that transform fields across the life sciences.


Assuntos
Inteligência Artificial , Biologia Computacional , Gerenciamento de Dados , Bases de Dados Factuais , Genoma , Internet
4.
Small ; 20(27): e2307202, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38308381

RESUMO

Thin-films of metal-organic frameworks (MOFs) have widespread potential applications, especially with the emergence of glass-forming MOFs, which remove the inherent issue of grain boundaries and allow coherent amorphous films to be produced. Herein, it is established that atomic layer deposition (ALD) of zinc oxide lends excellent control over the thickness and localization of resultant polycrystalline and glass zeolitic imidazole framework-62 (ZIF-62) thin-films within tubular α-alumina supports. Through the reduction of the chamber pressure and dose times during zinc oxide deposition, the resultant ZIF-62 films are reduced from 38 µm to 16 µm, while the presence of sporadic ZIF-62 (previously forming as far as 280 µm into the support) is prevented. Furthermore, the glass transformation shows a secondary reduction in film thickness from 16 to 2 µm.

5.
J Viral Hepat ; 2024 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-39445612

RESUMO

Despite the availability of effective treatment and vaccines for hepatitis B virus (HBV) and C virus (HCV), many people are still infected and remain unaware of their infection. The Camden and Islington Viral Hepatitis Identification Tool (CIVHIT), a computer-based search tool, was introduced in 60 general practices (GPs) in April 2014 to support identification, testing and treatment of individuals at high risk for blood-borne viruses (BBVs). CIVHIT searched electronic medical records (EMRs), flagging all those with codes linked to risk factors or medical conditions associated with BBVs. CIVHIT was associated with a 78.5% increase in BBV tests in primary care in both boroughs. This translated to a 55.8% rise in new diagnoses. HBV testing saw the largest increase resulting in twice as many people diagnosed. Only 23.2% of HBV and 14.9% of HCV-positive tests were referred to secondary care. In an index practice, the most common flag was a history of STIs (477/719, 66.3%). Individuals with previous or current drug use and those with a known hepatitis contact were more likely to be offered a test compared to those flagged due to a history of STI. HIV and HBV testing was lower in males following a test offer. There was an increased likelihood of testing for HBV and HCV with increasing age. Additionally, individuals with previous or current drug use and individuals with a known hepatitis contact were more likely to test for HCV compared to individuals flagged due to STI history. CIVHIT shows promise to assist with the elimination of BBVs.

6.
Artigo em Inglês | MEDLINE | ID: mdl-39316095

RESUMO

The introduction of dual-energy X-ray absorptiometry (DXA) technology in the 1980s revolutionized the diagnosis, management and monitoring of osteoporosis, providing a clinical tool which is now available worldwide. However, DXA measurements are influenced by many technical factors, including the quality control procedures for the instrument, positioning of the patient, and approach to analysis. Reporting of DXA results may be confounded by factors such as selection of reference ranges for T-scores and Z-scores, as well as inadequate knowledge of current standards for interpretation. These points are addressed at length in many international guidelines but are not always easily assimilated by practising clinicians and technicians. Our aim in this report is to identify key elements pertaining to the use of DXA in clinical practice, considering both technical and clinical aspects. Here, we discuss technical aspects of DXA procedures, approaches to interpretation and integration into clinical practice, and the use of non-bone mineral density measurements, such as a vertebral fracture assessment, in clinical risk assessment.

7.
Biomacromolecules ; 25(10): 6681-6692, 2024 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-39276065

RESUMO

The self-assembly of Janus-type amphiphilic hybrid block copolymers composed of hydrophilic/hydrophobic layers has shown promise for drug encapsulation and delivery. Saccharides have previously been incorporated to improve the biocompatibility of self-assembled structures; however, glycopolymer block copolymers have been less explored, and their structure-property relationships are not well understood. In this study, novel glycopolymer-branched poly(lactic acid) (PLA) block copolymers were synthesized via thiol-ene coupling and their composition-dependent morphologies were elucidated. Stability as a function of pH, dye uptake capabilities, and cytotoxicity were evaluated. Systems with a hydrophilic weight ratio of 30% were found to produce bilayer nanoparticles, while systems with a hydrophilic weight ratio of 60% form micelles upon self-assembly in aqueous media. Regardless of composition and morphology, all systems exhibited uptake of both hydrophobic (curcumin, DL % from 4.25 to 11.55) and hydrophilic (methyl orange, DL % from 4.08 to 5.88) dye molecules with release profiles dependent on composition. Furthermore, all of the nanoparticles exhibited low cytotoxicity, confirming their potential for biomedical applications.


Assuntos
Interações Hidrofóbicas e Hidrofílicas , Nanopartículas , Poliésteres , Poliésteres/química , Nanopartículas/química , Materiais Biocompatíveis/química , Humanos , Micelas , Curcumina/química , Curcumina/farmacologia , Polímeros/química
8.
PLoS Comput Biol ; 19(3): e1010964, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36881556

RESUMO

[This corrects the article DOI: 10.1371/journal.pcbi.1010220.].

9.
J Clin Densitom ; 27(1): 101452, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38228014

RESUMO

Osteoporosis can currently be diagnosed by applying the WHO classification to bone mineral density (BMD) assessed by dual-energy x-ray absorptiometry (DXA). However, skeletal factors other than BMD contribute to bone strength and fracture risk. Lumbar spine TBS, a grey-level texture measure which is derived from DXA images has been extensively studied, enhances fracture prediction independent of BMD and can be used to adjust fracture probability from FRAX® to improve risk stratification. The purpose of this International Society for Clinical Densitometry task force was to review the existing evidence and develop recommendations to assist clinicians regarding when and how to perform, report and utilize TBS. Our review concluded that TBS is most likely to alter clinical management in patients aged ≥ 40 years who are close to the pharmacologic intervention threshold by FRAX. The TBS value from L1-L4 vertebral levels, without vertebral exclusions, should be used to calculate adjusted FRAX probabilities. L1-L4 vertebral levels can be used in the presence of degenerative changes and lumbar compression fractures. It is recommended not to report TBS if extreme structural or pathological artifacts are present. Monitoring and reporting TBS change is unlikely to be helpful with the current version of the TBS algorithm. The next version of TBS software will include an adjustment based upon directly measured tissue thickness. This is expected to improve performance and address some of the technical factors that affect the current algorithm which may require modifications to these Official Positions as experience is acquired with this new algorithm.


Assuntos
Osteoporose , Fraturas por Osteoporose , Humanos , Osso Esponjoso/diagnóstico por imagem , Fraturas por Osteoporose/diagnóstico , Medição de Risco/métodos , Osteoporose/diagnóstico por imagem , Osteoporose/patologia , Densidade Óssea , Absorciometria de Fóton/métodos , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/patologia
10.
Gerontol Geriatr Educ ; : 1-12, 2024 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-38217514

RESUMO

Ageism is common in medical trainees and difficult to overcome. The My Life, My Story program has been shown to be an effective tool for increasing empathy. We explored its use as an instrument for combating ageism by implementing it in a Geriatrics clerkship for fourth year medical students. During our evaluation, 151 students interviewed patients about their lives using a semi-structured question guide. Students completed the UCLA Geriatrics Attitudes Scale and the Expectations Regarding Aging Survey pre-and post-clerkship. We also facilitated 9 student debriefs and 5 faculty interviews. After completing My Life, My Story, students were more likely to disagree with "I would rather see younger patients than elderly ones" and "it's normal to be depressed when you are old". In qualitative analysis of the debriefs, we identified a key summative theme: "impact of the intervention on care teams". Within that, we describe three subthemes: an awareness of richness of the lives led by older people, their current value to society, and the social determinants of health they have faced. After participating in My Life, My Story, students' attitudes toward aging changed. A narrative medicine program using life stories can be a practical tool for addressing ageist stereotypes.

11.
Mol Psychiatry ; 27(4): 1963-1969, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35246634

RESUMO

Alzheimer's disease (AD) is a genetically complex disease for which nearly 40 loci have now been identified via genome-wide association studies (GWAS). We attempted to identify groups of rare variants (alternate allele frequency <0.01) associated with AD in a region-based, whole-genome sequencing (WGS) association study (rvGWAS) of two independent AD family datasets (NIMH/NIA; 2247 individuals; 605 families). Employing a sliding window approach across the genome, we identified several regions that achieved association p values <10-6, using the burden test or the SKAT statistic. The genomic region around the dystobrevin beta (DTNB) gene was identified with the burden and SKAT test and replicated in case/control samples from the ADSP study reaching genome-wide significance after meta-analysis (pmeta = 4.74 × 10-8). SKAT analysis also revealed region-based association around the Discs large homolog 2 (DLG2) gene and replicated in case/control samples from the ADSP study (pmeta = 1 × 10-6). In conclusion, in a region-based rvGWAS of AD we identified two novel AD genes, DLG2 and DTNB, based on association with rare variants.


Assuntos
Doença de Alzheimer , Proteínas Associadas à Distrofina/genética , Neuropeptídeos/genética , Doença de Alzheimer/genética , Ácido Ditionitrobenzoico , Predisposição Genética para Doença/genética , Estudo de Associação Genômica Ampla , Genômica , Guanilato Quinases/genética , Humanos , Polimorfismo de Nucleotídeo Único/genética , Proteínas Supressoras de Tumor/genética , Sequenciamento Completo do Genoma
13.
Soft Matter ; 19(27): 5150-5159, 2023 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-37386911

RESUMO

Proteinaceous amyloids are well known for their widespread pathological roles but lately have emerged also as key components in several biological functions. The remarkable ability of amyloid fibers to form tightly packed conformations in a cross ß-sheet arrangement manifests in their robust enzymatic and structural stabilities. These characteristics of amyloids make them attractive for designing proteinaceous biomaterials for various biomedical and pharmaceutical applications. In order to design customizable and tunable amyloid nanomaterials, it is imperative to understand the sensitivity of the peptide sequence for subtle changes based on amino acid position and chemistry. Here we report our results from four rationally-designed amyloidogenic decapeptides that subtly differ in hydrophobicity and polarity at positions 5 and 6. We show that making the two positions hydrophobic renders the peptide with enhanced aggregation and material properties while introducing polar residues in position 5 dramatically changes the structure and nanomechanical properties of the fibrils formed. A charged residue at position 6, however, abrogates amyloid formation. In sum, we show that subtle changes in the sequence do not make the peptide innocuous but rather sensitive to aggregation, reflected in the biophysical and nanomechanical properties of the fibrils. We conclude that tolerance of peptide amyloid for changes in the sequence, however small they may be, should not be neglected for the effective design of customizable amyloid nanomaterials.


Assuntos
Amiloide , Peptídeos , Peptídeos/química , Amiloide/química , Sequência de Aminoácidos , Aminoácidos
14.
Dysphagia ; 38(4): 1025-1038, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36374337

RESUMO

Dysphagia (swallowing impairment) is a frequent complication of cervical spinal cord injury (cSCI). Recently published national guidance in the UK on rehabilitation after traumatic injury confirmed that people with cSCI are at risk for dysphagia and require early evaluation while remaining nil by mouth [National Institute for Health and Care Excellence. Rehabilitation after traumatic injury (NG211), 2022, https://www.nice.org.uk/guidance/ng21 ]. While the pathogenesis and pathophysiology of dysphagia in cSCI remains unclear, numerous risk factors have been identified in the literature. This review aims to summarize the literature on the risk factors, presentation, assessment, and management of dysphagia in patients with cSCI. A bespoke approach to dysphagia management, that accounts for the multiple system impairment in cSCI, is presented; the overarching aim of which is to support effective management of dysphagia in patients with cSCI to prevent adverse clinical consequences.


Assuntos
Medula Cervical , Transtornos de Deglutição , Traumatismos da Medula Espinal , Humanos , Transtornos de Deglutição/terapia , Transtornos de Deglutição/complicações , Medula Cervical/lesões , Medula Cervical/patologia , Traumatismos da Medula Espinal/complicações , Traumatismos da Medula Espinal/patologia , Traumatismos da Medula Espinal/reabilitação , Fatores de Risco , Boca
15.
J Environ Manage ; 345: 118835, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37659361

RESUMO

Grazing livestock plays an important role in the context of food security, agricultural sustainability and climate change. Understanding how livestock move and interact with their environment may offer new insights on how grazing practices impact soil and ecosystem functions at spatial and temporal scales where knowledge is currently limited. We characterized daily and seasonal grazing patterns using Global Positioning System (GPS) data from two grazing strategies: conventionally- and rotationally-grazed pastures. Livestock movement was consistent with the so-called Lévy walks, and could thus be simulated with Lévy-walk based probability density functions. Our newly introduced "Moovement model" links grazing patterns with soil structure and related functions by coupling animal movement and soil structure dynamics models, allowing to predict spatially-explicit changes in key soil properties. Predicted post-grazing management-specific bulk densities were consistent with field measurements and confirmed that rotational grazing produced similar disturbance as conventional grazing despite hosting higher stock densities. Harnessing information on livestock movement and its impacts in soil structure within a modelling framework can help testing and optimizing grazing strategies for ameliorating their impact on soil health and environment.


Assuntos
Ecossistema , Solo , Animais , Gado , Agricultura , Mudança Climática
16.
Biophys J ; 121(11): 2107-2126, 2022 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-35490297

RESUMO

Cytoplasmic inclusions containing aberrant proteolytic fragments of TDP-43 are associated with frontotemporal lobar degeneration (FTLD) and other related pathologies. In FTLD, TDP-43 is translocated into the cytoplasm and proteolytically cleaved to generate a prion-like domain (PrLD) containing C-terminal fragments (C25 and C35) that form toxic inclusions. Under stress, TDP-43 partitions into membraneless organelles called stress granules (SGs) by coacervating with RNA and other proteins. To study the factors that influence the dynamics between these cytoplasmic foci, we investigated the effects of cysteine-rich granulins (GRNs 1-7), which are the proteolytic products of progranulin, a protein implicated in FTLD, on TDP-43. We show that extracellular GRNs, typically generated during inflammation, internalize and colocalize with PrLD as puncta in the cytoplasm of neuroblastoma cells but show less likelihood of their presence in SGs. In addition, we show GRNs and PrLD coacervate to undergo liquid-liquid phase separation (LLPS) or form gel- or solid-like aggregates. Using charge patterning and conserved cysteines among the wild-type GRNs as guides, along with specifically engineered mutants, we discover that the negative charges on GRNs drive LLPS while the positive charges and the redox state of cysteines modulate these phase transitions. Furthermore, RNA and GRNs compete and expel one another from PrLD condensates, providing a basis for GRN's absence in SGs. Together, the results help uncover potential modulatory mechanisms by which extracellular GRNs, formed during chronic inflammatory conditions, could internalize and modulate cytoplasmic TDP-43 inclusions in proteinopathies.


Assuntos
Esclerose Lateral Amiotrófica , Proteínas de Ligação a DNA , Degeneração Lobar Frontotemporal , Granulinas , Esclerose Lateral Amiotrófica/metabolismo , Proteínas de Ligação a DNA/metabolismo , Degeneração Lobar Frontotemporal/metabolismo , Degeneração Lobar Frontotemporal/patologia , Granulinas/metabolismo , Humanos , Oxirredução , Agregação Patológica de Proteínas , RNA/metabolismo
17.
Thorax ; 77(6): 581-588, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-34706982

RESUMO

RATIONALE: Inhaled tobramycin and oral azithromycin are common chronic therapies in people with cystic fibrosis and Pseudomonas aeruginosa airway infection. Some studies have shown that azithromycin can reduce the ability of tobramycin to kill P. aeruginosa. This trial was done to test the effects of combining azithromycin with inhaled tobramycin on clinical and microbiological outcomes in people already using inhaled tobramycin. We theorised that those randomised to placebo (no azithromycin) would have greater improvement in forced expiratory volume in one second (FEV1) and greater reduction in P. aeruginosa sputum in response to tobramycin. METHODS: A 6-week prospective, randomised, placebo-controlled, double-blind trial testing oral azithromycin versus placebo combined with clinically prescribed inhaled tobramycin in individuals with cystic fibrosis and P. aeruginosa airway infection. RESULTS: Over a 6-week period, including 4 weeks of inhaled tobramycin, the relative change in FEV1 did not statistically significantly differ between groups (azithromycin (n=56) minus placebo (n=52) difference: 3.44%; 95% CI: -0.48 to 7.35; p=0.085). Differences in secondary clinical outcomes, including patient-reported symptom scores, weight and need for additional antibiotics, did not significantly differ. Among the 29 azithromycin and 35 placebo participants providing paired sputum samples, the 6-week change in P. aeruginosa density differed in favour of the placebo group (difference: 0.75 log10 CFU/mL; 95% CI: 0.03 to 1.47; p=0.043). CONCLUSIONS: Despite having greater reduction in P. aeruginosa density in participants able to provide sputum samples, participants randomised to placebo with inhaled tobramycin did not experience significantly greater improvements in lung function or other clinical outcomes compared with those randomised to azithromycin with tobramycin.


Assuntos
Fibrose Cística , Infecções por Pseudomonas , Administração por Inalação , Antibacterianos/uso terapêutico , Azitromicina , Fibrose Cística/complicações , Fibrose Cística/tratamento farmacológico , Volume Expiratório Forçado , Humanos , Estudos Prospectivos , Infecções por Pseudomonas/tratamento farmacológico , Pseudomonas aeruginosa , Tobramicina
18.
FASEB J ; 35(2): e21318, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33508158

RESUMO

Alzheimer's disease (AD) is a progressive neurodegenerative disorder that affects cognition and memory. Recent advances have helped identify many clinical sub-types in AD. Mounting evidence point toward structural polymorphism among fibrillar aggregates of amyloid-ß (Aß) to being responsible for the phenotypes and clinical manifestations. In the emerging paradigm of polymorphism and prion-like propagation of aggregates in AD, the role of low molecular weight soluble oligomers, which are long known to be the primary toxic agents, in effecting phenotypes remains inconspicuous. In this study, we present the characterization of three soluble oligomers of Aß42, namely 14LPOs, 16LPOs, and GM1Os with discreet biophysical and biochemical properties generated using lysophosphatidyl glycerols and GM1 gangliosides. The results indicate that the oligomers share some biophysical similarities but display distinctive differences with GM1Os. Unlike the other two, GM1Os were observed to be complexed with the lipid upon isolation. It also differs mainly in detection by conformation-sensitive dyes and conformation-specific antibodies, temperature and enzymatic stability, and in the ability to propagate morphologically-distinct fibrils. GM1Os also show distinguishable biochemical behavior with pronounced neuronal toxicity. Furthermore, all the oligomers induce cerebral amyloid angiopathy (CAA) and plaque burden in transgenic AD mice, which seems to be a consistent feature among all lipid-derived oligomers, but 16LPOs and GM1Os displayed significantly higher effect than the others. These results establish a correlation between molecular features of Aß42 oligomers and their distinguishable effects in transgenic AD mice attuned by lipid characteristics, and therefore help bridge the knowledge gap in understanding how oligomer conformers could elicit AD phenotypes.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Amiloide/metabolismo , Lipídeos/farmacologia , Amiloide/efeitos dos fármacos , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/fisiologia , Dicroísmo Circular , Difusão Dinâmica da Luz , Gangliosídeo G(M1)/farmacologia , Imuno-Histoquímica , Espectroscopia de Ressonância Magnética , Camundongos , Camundongos Transgênicos , Microscopia de Força Atômica , Fosfatidilgliceróis/farmacologia , Placa Amiloide/metabolismo , Espectrometria de Massas por Ionização por Electrospray , Espectroscopia de Infravermelho com Transformada de Fourier
19.
Biomacromolecules ; 23(1): 34-46, 2022 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-34793129

RESUMO

The black-legged tick (Ixodes scapularis) is the primary vector for bacteria that cause Lyme disease (Borrelia burgdorferi), where numerous glycosylated tick proteins are involved at the interface of vector-host-pathogen interactions. Reducing the expression of key tick proteins, such as selenoprotein K (SelK), through RNA interference is a promising approach to reduce pathogen transmission, but efficient delivery of nucleic acids to arthropods has proven challenging. While cationic glycopolymers have been used as nonviral gene delivery vehicles in mammalian cells, their use in arthropod or insect gene transfection has not been established. In this study, statistical acrylamide-based cationic glycopolymers with glucose or galactose pendant groups were synthesized by reversible addition-fragmentation chain transfer polymerization, and the effects of the saccharide pendant group and cationic monomer loading on polymer cytotoxicity, RNA complexation, and SelK gene knockdown in ISE6 cells were evaluated. All polymers exhibited low cytotoxicity, yet RNA/copolymer complex cell uptake and gene knockdown were highly dependent on the saccharide structure and the N:P (amino to phosphate groups) ratio.


Assuntos
Borrelia burgdorferi , Ixodes , Doença de Lyme , Animais , Proteínas de Artrópodes/metabolismo , Borrelia burgdorferi/metabolismo , Ixodes/genética , Ixodes/metabolismo , Ixodes/microbiologia , Doença de Lyme/genética , Doença de Lyme/microbiologia , Interferência de RNA
20.
Macromol Rapid Commun ; 43(24): e2200487, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35822234

RESUMO

Incorporating dynamic covalent bonds into block copolymers provides useful molecular level information during mechanical testing, but it is currently unknown how the incorporation of these units affects the resultant polymer morphology. High-molecular-weight polyisobutylene-b-polystyrene block copolymers containing an anthracene/maleimide dynamic covalent bond are synthesized through a combination of postpolymerization modification, reversible addition-fragmentation chain-transfer polymerization, and Diels-Alder coupling. The bulk morphologies with and without dynamic covalent bond are characterized by atomic force microscopy  and small-angle X-ray scattering, which reveal a strong dependence on annealing time and casting solvent. Morphology is largely unaffected by the inclusion of the mechanophore. The high-molecular-weight polymers synthesized allow interrogation of a large range of polymer domain sizes.

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