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1.
Immunity ; 55(11): 2118-2134.e6, 2022 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-36137543

RESUMO

While blood antibodies mediate protective immunity in most organs, whether they protect nasal surfaces in the upper airway is unclear. Using multiple viral infection models in mice, we found that blood-borne antibodies could not defend the olfactory epithelium. Despite high serum antibody titers, pathogens infected nasal turbinates, and neurotropic microbes invaded the brain. Using passive antibody transfers and parabiosis, we identified a restrictive blood-endothelial barrier that excluded circulating antibodies from the olfactory mucosa. Plasma cell depletions demonstrated that plasma cells must reside within olfactory tissue to achieve sterilizing immunity. Antibody blockade and genetically deficient models revealed that this local immunity required CD4+ T cells and CXCR3. Many vaccine adjuvants failed to generate olfactory plasma cells, but mucosal immunizations established humoral protection of the olfactory surface. Our identification of a blood-olfactory barrier and the requirement for tissue-derived antibody has implications for vaccinology, respiratory and CNS pathogen transmission, and B cell fate decisions.


Assuntos
Linfócitos B , Plasmócitos , Animais , Camundongos , Linfócitos T , Imunoglobulinas , Encéfalo , Imunidade nas Mucosas , Anticorpos Antivirais
2.
Proc Natl Acad Sci U S A ; 121(16): e2401148121, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38602914

RESUMO

The oxidation of cycloalkanes is important in the combustion of transportation fuels and in atmospheric secondary organic aerosol formation. A transient carbon-centered radical intermediate (•QOOH) in the oxidation of cyclohexane is identified through its infrared fingerprint and time- and energy-resolved unimolecular dissociation dynamics to hydroxyl (OH) radical and bicyclic ether products. Although the cyclohexyl ring structure leads to three nearly degenerate •QOOH isomers (ß-, γ-, and δ-QOOH), their transition state (TS) barriers to OH products are predicted to differ considerably. Selective characterization of the ß-QOOH isomer is achieved at excitation energies associated with the lowest TS barrier, resulting in rapid unimolecular decay to OH products that are detected. A benchmarking approach is employed for the calculation of high-accuracy stationary point energies, in particular TS barriers, for cyclohexane oxidation (C6H11O2), building on higher-level reference calculations for the smaller ethane oxidation (C2H5O2) system. The isomer-specific characterization of ß-QOOH is validated by comparison of experimental OH product appearance rates with computed statistical microcanonical rates, including significant heavy-atom tunneling, at energies in the vicinity of the TS barrier. Master-equation modeling is utilized to extend the results to thermal unimolecular decay rate constants at temperatures and pressures relevant to cyclohexane combustion.

3.
Proc Natl Acad Sci U S A ; 120(47): e2312995120, 2023 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-37956290

RESUMO

A model for antibiotic accumulation in bacterial biofilm microcolonies utilizing heterogenous porosity and attachment site profiles replicated the periphery sequestration reported in prior experimental studies on Pseudomonas aeruginosa PAO1 biofilm cell clusters. These P. aeruginosa cell clusters are in vitro models of the chronic P. aeruginosa infections in cystic fibrosis patients which display recalcitrance to antibiotic treatments, leading to exacerbated morbidity and mortality. This resistance has been partially attributed to periphery sequestration, where antibiotics fail to penetrate biofilm cell clusters. The physical phenomena driving this periphery sequestration have not been definitively established. This paper introduces mathematical models to account for two proposed physical phenomena driving periphery sequestration: biofilm matrix attachment and volume-exclusion due to variable biofilm porosity. An antibiotic accumulation model which incorporated these phenomena better fit observed periphery sequestration data compared to previous models.


Assuntos
Fibrose Cística , Infecções por Pseudomonas , Humanos , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Pseudomonas aeruginosa , Biofilmes , Matriz Extracelular de Substâncias Poliméricas , Fibrose Cística/tratamento farmacológico , Fibrose Cística/microbiologia , Infecções por Pseudomonas/tratamento farmacológico , Infecções por Pseudomonas/microbiologia
4.
Mol Microbiol ; 122(1): 81-112, 2024 07.
Artigo em Inglês | MEDLINE | ID: mdl-38847475

RESUMO

DNA in bacterial chromosomes is organized into higher-order structures by DNA-binding proteins called nucleoid-associated proteins (NAPs) or bacterial chromatin proteins (BCPs). BCPs often bind to or near DNA loci transcribed by RNA polymerase (RNAP) and can either increase or decrease gene expression. To understand the mechanisms by which BCPs alter transcription, one must consider both steric effects and the topological forces that arise when DNA deviates from its fully relaxed double-helical structure. Transcribing RNAP creates DNA negative (-) supercoils upstream and positive (+) supercoils downstream whenever RNAP and DNA are unable to rotate freely. This (-) and (+) supercoiling generates topological forces that resist forward translocation of DNA through RNAP unless the supercoiling is constrained by BCPs or relieved by topoisomerases. BCPs also may enhance topological stress and overall can either inhibit or aid transcription. Here, we review current understanding of how RNAP, BCPs, and DNA topology interplay to control gene expression.


Assuntos
Proteínas de Bactérias , Cromatina , DNA Bacteriano , RNA Polimerases Dirigidas por DNA , Regulação Bacteriana da Expressão Gênica , Transcrição Gênica , DNA Bacteriano/metabolismo , DNA Bacteriano/genética , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Cromatina/metabolismo , RNA Polimerases Dirigidas por DNA/metabolismo , RNA Polimerases Dirigidas por DNA/genética , DNA Super-Helicoidal/metabolismo , DNA Super-Helicoidal/genética , Proteínas de Ligação a DNA/metabolismo , Proteínas de Ligação a DNA/genética , Bactérias/metabolismo , Bactérias/genética , Cromossomos Bacterianos/metabolismo , Cromossomos Bacterianos/genética
5.
Proc Natl Acad Sci U S A ; 119(6)2022 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-35110400

RESUMO

Oncogenic imbalance of DNA methylation is well recognized in cancer development. The ten-eleven translocation (TET) family of dioxygenases, which facilitates DNA demethylation, is frequently dysregulated in cancers. How such dysregulation contributes to tumorigenesis remains poorly understood, especially in solid tumors which present infrequent mutational incidence of TET genes. Here, we identify loss-of-function mutations of TET in 7.4% of human lung adenocarcinoma (LUAD), which frequently co-occur with oncogenic KRAS mutations, and this co-occurrence is predictive of poor survival in LUAD patients. Using an autochthonous mouse model of KrasG12D -driven LUAD, we show that individual or combinational loss of Tet genes markedly promotes tumor development. In this Kras-mutant and Tet-deficient model, the premalignant lung epithelium undergoes neoplastic reprogramming of DNA methylation and transcription, with a particular impact on Wnt signaling. Among the Wnt-associated components that undergo reprogramming, multiple canonical Wnt antagonizing genes present impaired expression arising from elevated DNA methylation, triggering aberrant activation of Wnt signaling. These impairments can be largely reversed upon the restoration of TET activity. Correspondingly, genetic depletion of ß-catenin, the transcriptional effector of Wnt signaling, substantially reverts the malignant progression of Tet-deficient LUAD. These findings reveal TET enzymes as critical epigenetic barriers against lung tumorigenesis and highlight the therapeutic vulnerability of TET-mutant lung cancer through targeting Wnt signaling.


Assuntos
Adenocarcinoma de Pulmão/metabolismo , Metilação de DNA , DNA de Neoplasias/metabolismo , Neoplasias Pulmonares/metabolismo , Neoplasias Experimentais/metabolismo , Proteínas Proto-Oncogênicas/deficiência , Via de Sinalização Wnt , Adenocarcinoma de Pulmão/genética , Animais , DNA de Neoplasias/genética , Humanos , Neoplasias Pulmonares/genética , Camundongos , Camundongos Transgênicos , Neoplasias Experimentais/genética , Proteínas Proto-Oncogênicas/metabolismo
6.
BMC Biol ; 22(1): 178, 2024 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-39183269

RESUMO

BACKGROUND: The previously underestimated effects of commensal gut microbiota on the human body are increasingly being investigated using omics. The discovery of active molecules of interaction between the microbiota and the host may be an important step towards elucidating the mechanisms of symbiosis. RESULTS: Here, we show that in the bloodstream of healthy people, there are over 900 peptides that are fragments of proteins from microorganisms which naturally inhabit human biotopes, including the intestinal microbiota. Absolute quantitation by multiple reaction monitoring has confirmed the presence of bacterial peptides in the blood plasma and serum in the range of approximately 0.1 nM to 1 µM. The abundance of microbiota peptides reaches its maximum about 5 h after a meal. Most of the peptides correlate with the bacterial composition of the small intestine and are likely obtained by hydrolysis of membrane proteins with trypsin, chymotrypsin and pepsin - the main proteases of the gastrointestinal tract. The peptides have physicochemical properties that likely allow them to selectively pass the intestinal mucosal barrier and resist fibrinolysis. CONCLUSIONS: The proposed approach to the identification of microbiota peptides in the blood, after additional validation, may be useful for determining the microbiota composition of hard-to-reach intestinal areas and monitoring the permeability of the intestinal mucosal barrier.


Assuntos
Microbioma Gastrointestinal , Peptídeos , Humanos , Microbioma Gastrointestinal/fisiologia , Peptídeos/análise , Masculino , Adulto
7.
Artigo em Inglês | MEDLINE | ID: mdl-39389125

RESUMO

BACKGROUND: Acute exacerbations of chronic rhinosinusitis (AECRS) are commonly triggered by rhinovirus (RV) infections with secondary bacterial infections. Risk factors for AECRS are not well understood. OBJECTIVE: To determine if carriers of the minor allele rs6967330 (AA/AG) in the Cadherin related family member 3 (CDHR3) gene have an increased risk for RV infections in AECRS in vivo and identify CDHR3 genotype-dependent host responses to RV infection in differentiated nasal airway liquid interface (ALI) cultures ex vivo. METHODS: We performed a prospective year-long study of adult subjects with chronic rhinosinusitis (CRS) by rs6967330 genotype (AA/AG, n=16; GG, n=38). We contacted subjects every 2 weeks, and if they reported AECRS clinical data were collected. ALI cultures of adults with CRS (AG/AA,n=19; GG,n=19) were challenged with RV-A and RV-C. We measured viral copy numbers at 4- and 48-hours post-infection and RNA transcriptomes and cytokines at 48 hours post infection. RESULTS: Subjects with the minor allele had significantly higher rates of RV and bacterial infections than those with the major allele. ALI minor allele cultures had higher viral copy numbers of RV-A and RV-C after 48 hours compared to the major allele. Differentially expressed genes (DEG) and pathways identified an upregulation of IL-10 and IL4/13 pathways and a significant downregulation of toll like receptor (TLR) pathways in the minor allele cultures after RV-A and RV-C infection. Unsupervised hierarchical analysis of all DEGs suggest that allergic rhinitis had an additive effect on this response. CONCLUSIONS: The rs6967330 minor allele is associated with increased RV-A and RV-C replication, downregulation of TLR-mediated responses and increased T2-type and cytokine and chemokine responses during RV infection.

8.
Diabetologia ; 67(2): 223-235, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37979006

RESUMO

The discourse amongst diabetes specialists and academics regarding technology and artificial intelligence (AI) typically centres around the 10% of people with diabetes who have type 1 diabetes, focusing on glucose sensors, insulin pumps and, increasingly, closed-loop systems. This focus is reflected in conference topics, strategy documents, technology appraisals and funding streams. What is often overlooked is the wider application of data and AI, as demonstrated through published literature and emerging marketplace products, that offers promising avenues for enhanced clinical care, health-service efficiency and cost-effectiveness. This review provides an overview of AI techniques and explores the use and potential of AI and data-driven systems in a broad context, covering all diabetes types, encompassing: (1) patient education and self-management; (2) clinical decision support systems and predictive analytics, including diagnostic support, treatment and screening advice, complications prediction; and (3) the use of multimodal data, such as imaging or genetic data. The review provides a perspective on how data- and AI-driven systems could transform diabetes care in the coming years and how they could be integrated into daily clinical practice. We discuss evidence for benefits and potential harms, and consider existing barriers to scalable adoption, including challenges related to data availability and exchange, health inequality, clinician hesitancy and regulation. Stakeholders, including clinicians, academics, commissioners, policymakers and those with lived experience, must proactively collaborate to realise the potential benefits that AI-supported diabetes care could bring, whilst mitigating risk and navigating the challenges along the way.


Assuntos
Inteligência Artificial , Diabetes Mellitus Tipo 1 , Humanos , Disparidades nos Níveis de Saúde , Diabetes Mellitus Tipo 1/terapia
9.
Plant J ; 115(6): 1528-1543, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37258460

RESUMO

Despite the importance of hybridization in evolution, the evolutionary consequence of homoploid hybridizations in plants remains poorly understood. Specially, homoploid hybridization events have been rarely documented due to a lack of genomic resources and methodological limitations. Actinidia zhejiangensis was suspected to have arisen from hybridization of Actinidia eriantha and Actinidia hemsleyana or Actinidia rufa. However, this species was very rare in nature and exhibited sympatric distribution with its potential parent species, which implied it might be a spontaneous hybrid of ongoing homoploid hybridization. Here, we illustrate the dead-end homoploid hybridization and genomic basis of isolating barriers between A. eriantha and A. hemsleyana through whole genome sequencing and population genomic analyses. Chromosome-scale genome assemblies of A. zhejiangensis and A. hemsleyana were generated. The chromosomes of A. zhejiangensis are confidently assigned to the two haplomes, and one of them originates from A. eriantha and the other originates from A. hemsleyana. Whole genome resequencing data reveal that A. zhejiangensis are mainly F1 hybrids of A. hemsleyana and A. eriantha and gene flow initiated about 0.98 million years ago, implying both strong genetic barriers and ongoing hybridization between these two deeply divergent kiwifruit species. Five inversions containing genes involved in pollen germination and pollen tube growth might account for the fertility breakdown of hybrids between A. hemsleyana and A. eriantha. Despite its distinct morphological traits and long recurrent hybrid origination, A. zhejiangensis does not initiate speciation. Collectively, our study provides new insights into homoploid hybridization in plants and provides genomic resources for evolutionary and functional genomic studies of kiwifruit.


Assuntos
Actinidia , Actinidia/genética , Actinidia/metabolismo , Hibridização Genética , Genoma , Genômica , Plantas/genética , Especiação Genética
10.
Int J Cancer ; 155(4): 719-730, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-38648380

RESUMO

There is a gap in the understanding of the barriers to cancer screening participation and complying with downstream management in the Community of Latin American and Caribbean states (CELAC). Our study aimed to assess barriers across the cancer screening pathway from the health system perspective, and interventions in place to improve screening in CELAC. A standardized tool was used to collect information on the barriers across the screening pathway through engagement with the health authorities of 27 member states of CELAC. Barriers were organized in a framework adapted from the Tanahashi conceptual model and consisted of the following dimensions: availability of services, access (covering accessibility and affordability), acceptability, user-provider interaction, and effectiveness of services (which includes governance, protocols and guidelines, information system, and quality assurance). The tool also collected information of interventions in place, categorized in user-directed interventions to increase demand, user-directed interventions to increase access, provider-directed interventions, and policy and system-level interventions. All countries prioritized barriers related to the information systems, such as the population register not being accurate or complete (N = 19; 70.4%). All countries implemented some kind of intervention to improve cancer screening, group education being the most reported (N = 23; 85.2%). Training on screening delivery was the most referred provider-directed intervention (N = 19; 70.4%). The study has identified several barriers to the implementation of cancer screening in the region and interventions in place to overcome some of the barriers. Further analysis is required to evaluate the effectiveness of these interventions in achieving their objectives.


Assuntos
Detecção Precoce de Câncer , Acessibilidade aos Serviços de Saúde , Neoplasias , Humanos , América Latina , Detecção Precoce de Câncer/estatística & dados numéricos , Região do Caribe/epidemiologia , Neoplasias/diagnóstico , Neoplasias/prevenção & controle , Feminino
11.
Mol Biol Evol ; 40(5)2023 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-37146165

RESUMO

Landscape, climate, and culture can all structure human populations, but few existing methods are designed to simultaneously disentangle among a large number of variables in explaining genetic patterns. We developed a machine learning method for identifying the variables which best explain migration rates, as measured by the coalescent-based program MAPS that uses shared identical by descent tracts to infer spatial migration across a region of interest. We applied our method to 30 human populations in eastern Africa with high-density single nucleotide polymorphism array data. The remarkable diversity of ethnicities, languages, and environments in this region offers a unique opportunity to explore the variables that shape migration and genetic structure. We explored more than 20 spatial variables relating to landscape, climate, and presence of tsetse flies. The full model explained ∼40% of the variance in migration rate over the past 56 generations. Precipitation, minimum temperature of the coldest month, and elevation were the variables with the highest impact. Among the three groups of tsetse flies, the most impactful was fusca which transmits livestock trypanosomiasis. We also tested for adaptation to high elevation among Ethiopian populations. We did not identify well-known genes related to high elevation, but we did find signatures of positive selection related to metabolism and disease. We conclude that the environment has influenced the migration and adaptation of human populations in eastern Africa; the remaining variance in structure is likely due in part to cultural or other factors not captured in our model.


Assuntos
Migração Humana , Modelos Genéticos , Humanos , Clima , Animais , Moscas Tsé-Tsé , Estudo de Associação Genômica Ampla , África Oriental , Genética Humana , Genômica , Idioma
12.
Cancer ; 130 Suppl 20: 3590-3601, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-38837334

RESUMO

BACKGROUND: Despite mandated insurance coverage since 2006 and robust health infrastructure in urban settings with high concentrations of minority patients, race-based disparities in prostate cancer (PCa) treatment persist in Massachusetts. In this qualitative study, the authors sought to identify factors driving inequities in PCa treatment in Massachusetts. METHODS: Four hospitals offering PCa treatment in Massachusetts were selected using a case-mix approach. Purposive sampling was used to conduct semistructured interviews with hospital stakeholders. Additional interviews were conducted with representatives from grassroots organizations providing PCa education. Two study staff coded the interviews to identify major themes and recurrent patterns. RESULTS: Of the 35 informants invited, 25 participated in the study. Although national disparities in PCa outcomes were readily discussed, one half of the informants were unaware that PCa disparities existed in Massachusetts. Informants and grassroots organization representatives acknowledged that patients with PCa are willing to face transportation barriers to receive treatment from trusted and accommodating institutions. Except for chief equity officers, most health care providers lacked knowledge on accessing or using metrics regarding racial disparities in cancer outcomes. Although community outreach was recognized as a potential strategy to reduce treatment disparities and engender trust, informants were often unable to provide a clear implementation plan. CONCLUSIONS: This statewide qualitative study builds on existing quantitative data on the nature and extent of disparities. It highlights knowledge gaps in recognizing and addressing racial disparities in PCa treatment in Massachusetts. Improved provider awareness, the use of disparity metrics, and strategic community engagement may ensure equitable access to PCa treatment. PLAIN LANGUAGE SUMMARY: Despite mandated insurance and urban health care access, racial disparities in prostate cancer treatment persist in Massachusetts. This qualitative study revealed that, although national disparities were acknowledged, awareness about local disparities are lacking. Stakeholders highlighted the importance of ancillary services, including translators, rideshares, and navigators, in the delivery of care. In addition, whereas hospital stakeholders were aware of collected equity outcomes, they were unsure whether and who is monitoring equity metrics. Furthermore, stakeholders agreed that community outreach showed promise in ensuring equitable access to prostate cancer treatment. Nevertheless, most interviewed stakeholders lacked clear implementation plans.


Assuntos
Negro ou Afro-Americano , Acessibilidade aos Serviços de Saúde , Disparidades em Assistência à Saúde , Neoplasias da Próstata , Pesquisa Qualitativa , Humanos , Masculino , Neoplasias da Próstata/terapia , Neoplasias da Próstata/etnologia , Massachusetts , Disparidades em Assistência à Saúde/etnologia , Acessibilidade aos Serviços de Saúde/estatística & dados numéricos , Negro ou Afro-Americano/estatística & dados numéricos
13.
Cancer ; 130(1): 11-15, 2024 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-37851508

RESUMO

Enrollment in cancer clinical trials cannot occur without first successfully identifying trials for which patients are a match based on their clinical characteristics. A lack of onsite matching trials has been identified as the single largest barrier preventing patients from participating in clinical trials. The site-agnostic cancer clinical trial matching environment is a mix of public and private tools and infrastructure that are not designed to work together to facilitate trial matching in an efficient manner. To identify policy and infrastructure solutions that could enable more effective and more frequent use of third-party site-agnostic matching, the American Cancer Society Cancer Action Network held a summit to examine challenges and propose consensus recommendations that could address those challenges. At this 2019 summit, stakeholders in this field examined these barriers and challenges and made a number of policy and infrastructure recommendations to improve the ability of this environment to work in a more coordinated and efficient manner.


Assuntos
Neoplasias , Humanos , Consenso , Neoplasias/terapia , Cuidados Paliativos , Ensaios Clínicos como Assunto
14.
Cancer ; 130(1): 68-76, 2024 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-37851511

RESUMO

BACKGROUND: Provider and institutional practices have been shown to have a large impact on cancer clinical trial enrollment. Understanding provider perspectives on screening for trial eligibility is necessary to improve enrollment. METHODS: A questionnaire about incentives, barriers, process tools, and infrastructure related to opening trials and referring patients to onsite and offsite trials was administered to diverse stakeholders, including professional societies, advocacy organizations, and industry networks. Descriptive statistics were used to summarize findings. RESULTS: Overall, 693 responses were received, primarily from physicians (42.7%) and nurses (35.6%) employed at hospital health systems (43.7%) and academic centers (36.5%). Approximately half (49.2%) screened all patients for onsite clinical trials with screening typically done by manual chart review (81.9%). The greatest incentive reported for offering trials was providing the best treatment options for patients (67.7%). Contracting and paperwork (48.5%) were the greatest barriers to opening more onsite trials. Offsite referrals were rare. CONCLUSIONS: Screening for trial eligibility is a largely manual and ad hoc process, with screening and referral to offsite trials occurring infrequently. Administrative and infrastructure barriers commonly prevent sites from opening more onsite trials. These findings suggest that automated trial screening tools built into workflows that screen in a site-agnostic manner could result in more frequent trial eligibility screening, especially for offsite trials. With recent momentum, in part in response to the COVID-19 pandemic, to improve clinical trial efficiencies and broaden access and participant diversity, implementing tools to improve screening and referral processes is timely and essential. PLAIN LANGUAGE SUMMARY: There are many factors that contribute to low adult enrollment in cancer clinical trials, but previous research has indicated that provider and institutional barriers are the largest contributors to low cancer clinical trial enrollment. In this survey, we sought to gain insight into cancer clinical trial enrollment practices from the perspective of health care providers such as physicians and nurses. We found that only approximately half of respondents indicated their institution systematically screens their patients for clinical trials and this process is manual and time consuming. Furthermore, we found that providers infrequently search for and refer patients to clinical trials at other sites. Creating better screening methods could improve enrollment in clinical trials.


Assuntos
Motivação , Neoplasias , Adulto , Humanos , Detecção Precoce de Câncer , Neoplasias/diagnóstico , Neoplasias/terapia , Pandemias , Encaminhamento e Consulta , Inquéritos e Questionários , Ensaios Clínicos como Assunto
15.
EMBO J ; 39(9): e103894, 2020 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-32187732

RESUMO

Production of reactive oxygen species (ROS) by NADPH oxidases (NOXs) impacts many processes in animals and plants, and many plant receptor pathways involve rapid, NOX-dependent increases of ROS. Yet, their general reactivity has made it challenging to pinpoint the precise role and immediate molecular action of ROS. A well-understood ROS action in plants is to provide the co-substrate for lignin peroxidases in the cell wall. Lignin can be deposited with exquisite spatial control, but the underlying mechanisms have remained elusive. Here, we establish a kinase signaling relay that exerts direct, spatial control over ROS production and lignification within the cell wall. We show that polar localization of a single kinase component is crucial for pathway function. Our data indicate that an intersection of more broadly localized components allows for micrometer-scale precision of lignification and that this system is triggered through initiation of ROS production as a critical peroxidase co-substrate.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Lignina/metabolismo , Proteínas Quinases/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Regulação da Expressão Gênica de Plantas , NADPH Oxidases/metabolismo , Peroxidases/metabolismo , Raízes de Plantas/metabolismo
16.
Funct Integr Genomics ; 24(5): 177, 2024 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-39340586

RESUMO

After COVID-19, a turning point in the way of pharmaceutical technology is gene therapy with beneficial potential to start a new medical era. However, commercialization of such pharmaceuticals would never be possible without the help of nanotechnology. Nanomedicine can fulfill the growing needs linked to safety, efficiency, and site-specific targeted delivery of Gene therapy-based pharmaceuticals. This review's goal is to investigate how nanomedicine may be used to transfer nucleic acids by getting beyond cellular and physicochemical barriers. Firstly, we provide a full description of types of gene therapy, their mechanism, translation, transcription, expression, type, and details of diseases with possible mechanisms that can only be treated with genes-based pharmaceuticals. Additionally, we also reviewed different types of physicochemical barriers, physiological and cellular barriers in nucleic acids (DNA/RNA) based drug delivery. Finally, we highlight the need and importance of cationic lipid-based nanomedicine/nanocarriers in gene-linked drug delivery and how nanotechnology can help to overcome the above-discussed barrier in gene therapy and their biomedical applications.


Assuntos
Terapia Genética , Nanomedicina , Humanos , Terapia Genética/métodos , Nanomedicina/métodos , Nanopartículas/química , Sistemas de Liberação de Medicamentos , Técnicas de Transferência de Genes , COVID-19/terapia , Animais
17.
Development ; 148(12)2021 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-34132325

RESUMO

Growing human organs in animals sounds like something from the realm of science fiction, but it may one day become a reality through a technique known as interspecies blastocyst complementation. This technique, which was originally developed to study gene function in development, involves injecting donor pluripotent stem cells into an organogenesis-disabled host embryo, allowing the donor cells to compensate for missing organs or tissues. Although interspecies blastocyst complementation has been achieved between closely related species, such as mice and rats, the situation becomes much more difficult for species that are far apart on the evolutionary tree. This is presumably because of layers of xenogeneic barriers that are a result of divergent evolution. In this Review, we discuss the current status of blastocyst complementation approaches and, in light of recent progress, elaborate on the keys to success for interspecies blastocyst complementation and organ generation.


Assuntos
Blastocisto/citologia , Quimera , Organogênese , Transplantes , Animais , Apoptose , Blastocisto/metabolismo , Diferenciação Celular , Histocompatibilidade , Humanos , Gado , Especificidade de Órgãos , Células-Tronco Pluripotentes/citologia , Células-Tronco Pluripotentes/metabolismo , Transplante Heterólogo
18.
Adv Funct Mater ; 34(8)2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38828467

RESUMO

Most nanomedicines require efficient in vivo delivery to elicit diagnostic and therapeutic effects. However, en route to their intended tissues, systemically administered nanoparticles often encounter delivery barriers. To describe these barriers, we propose the term "nanoparticle blood removal pathways" (NBRP), which summarizes the interactions between nanoparticles and the body's various cell-dependent and cell-independent blood clearance mechanisms. We reviewed nanoparticle design and biological modulation strategies to mitigate nanoparticle-NBRP interactions. As these interactions affect nanoparticle delivery, we studied the preclinical literature from 2011-2021 and analyzed nanoparticle blood circulation and organ biodistribution data. Our findings revealed that nanoparticle surface chemistry affected the in vivo behavior more than other nanoparticle design parameters. Combinatory biological-PEG surface modification improved the blood area under the curve by ~418%, with a decrease in liver accumulation of up to 47%. A greater understanding of nanoparticle-NBRP interactions and associated delivery trends will provide new nanoparticle design and biological modulation strategies for safer, more effective, and more efficient nanomedicines.

19.
Small ; : e2403640, 2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-38963162

RESUMO

Ensuring precise drug release at target sites is crucial for effective treatment. Here, pH-responsive nanoparticles for oral administration of mycophenolate mofetil, an alternative therapy for patients with inflammatory bowel disease unresponsive to conventional treatments is developed. However, its oral administration presents challenges due to its low solubility in the small intestine and high solubility and absorption in the stomach. Therefore, this aim is to design a drug delivery system capable of maintaining drug solubility compared to the free drug while delaying absorption from the stomach to the intestine. Successful synthesis and assembly of a block copolymer incorporating a pH-responsive functional group is achieved. Dynamic light scattering indicated a significant change in hydrodynamic size when the pH exceeded 6.5, confirming successful incorporation of the pH-responsive group. Encapsulation and controlled release of mycophenolate mofetil are efficiently demonstrated, with 90% release observed at intestinal pH. In vitro cell culture studies confirmed biocompatibility, showing no toxicity or adverse effects on Caco-2 cells. In vivo oral rat studies indicated reduced drug absorption in the stomach and enhanced absorption in the small intestine with the developed formulation. This research presents a promising drug delivery system with potential applications in the treatment of inflammatory bowel disease.

20.
Small ; 20(27): e2310908, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38279585

RESUMO

The high potassization/depotassization energy barriers and lack of efficient ion diffusion pathways are two serious obstacles for carbon-based materials to achieve satisfactory potassium ion storage performance. Herein, a facile and controllable one-step exfoliation-doping-etching strategy is proposed to construct heteroatoms (N, O, and S)-doped mesoporous few-layer carbon nanosheets (NOS-C). The mixed molten salts of KCl/K2SO4 are innovatively used as the exfoliators, dopants, and etching agents, which enable NOS-C with expanded interlayer spacing and uniformly distributed mesopores with the adjusted electronic structure of surrounding carbon atoms, contributing efficient dual (vertical and horizontal) K-ion diffusion pathways, low potassization/depotassization energy barriers and abundant active sites. Thus, the NOS anodes achieve a high reversible capacity of 516.8 mAh g-1 at 0.05 A g-1, superior rate capability of 202.8 mAh g-1 at 5 A g-1 and excellent long-term cyclic stability, and their practical application potential is demonstrated by the assembled potassium-ion full batteries. Moreover, a surface-interlayer synergetic K+ storage mechanism is revealed by a combined theoretical and experimental approach including in situ EIS, in situ Raman, ex situ XPS, and SEM analysis. The proposed K+ storage mechanism and unique structural engineering provide a new pathway for potassium-ion storage devices and even beyond.

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