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1.
Cell Mol Life Sci ; 79(2): 78, 2022 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-35044538

RESUMO

Three-dimensional (3D) in vitro culture systems using human induced pluripotent stem cells (hiPSCs) are useful tools to model neurodegenerative disease biology in physiologically relevant microenvironments. Though many successful biomaterials-based 3D model systems have been established for other neurogenerative diseases, such as Alzheimer's disease, relatively few exist for Parkinson's disease (PD) research. We employed tissue engineering approaches to construct a 3D silk scaffold-based platform for the culture of hiPSC-dopaminergic (DA) neurons derived from healthy individuals and PD patients harboring LRRK2 G2019S or GBA N370S mutations. We then compared results from protein, gene expression, and metabolic analyses obtained from two-dimensional (2D) and 3D culture systems. The 3D platform enabled the formation of dense dopamine neuronal network architectures and developed biological profiles both similar and distinct from 2D culture systems in healthy and PD disease lines. PD cultures developed in 3D platforms showed elevated levels of α-synuclein and alterations in purine metabolite profiles. Furthermore, computational network analysis of transcriptomic networks nominated several novel molecular interactions occurring in neurons from patients with mutations in LRRK2 and GBA. We conclude that the brain-like 3D system presented here is a realistic platform to interrogate molecular mechanisms underlying PD biology.


Assuntos
Neurônios Dopaminérgicos/patologia , Doença de Parkinson/patologia , Bioengenharia , Técnicas de Cultura de Células em Três Dimensões , Células Cultivadas , Neurônios Dopaminérgicos/citologia , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/patologia , Neurogênese , Seda/química , Alicerces Teciduais/química
2.
Environ Geochem Health ; 46(1): 17, 2023 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-38147234

RESUMO

In order to supply wholesome food and slow down climate change, this paper covers India's agrogeological resources. The soils are the result of the weathering of rocks with ages ranging from more than a billion years to the most recent Holocene. Because they are severely deficient in vital minerals, many soils have low agricultural production. In addition to helping to fertilise soils, reduce atmospheric carbon dioxide levels, and stop the acidification of the Indian Ocean, rock powder weathering and biochar have significant positive effects on the productivity of Indian soils. The nutrient density of food is also increased which improves health and lowers the demand for and cost of medical treatment. Remineralization may help to solve Indian soil issues including soil infertility and texture. To improve soil and plant nutrition, dusts of carbonate, basic, and ultrabasic rocks are readily available at mining sites in India combined with biochar. Adding different grain sizes to the soil helps improve the texture of the soil. Silicate and carbonate rock powders enhance soil structure by promoting the creation of soil organic matter and fostering the growth of advantageous microbial communities. These processes offer a low-cost method of remineralizing soils with important macro- and micronutrients. For each significant soil/crop/climate system, an optimised application of India's rock powder resources must be determined through a national research and development programme. India's capacity to adapt to the mounting challenges of population expansion and climate change would be significantly improved by the findings of this study programme.


Assuntos
Segurança Alimentar , Solo , Pós , Índia , Carbonatos
3.
Inorg Chem ; 61(46): 18458-18465, 2022 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-36346922

RESUMO

Metal-organic framework crystal-glass composites (MOF CGCs) are a class of materials comprising a crystalline framework embedded within a MOF glass matrix. Herein, we investigate the thermal expansion behavior of three MOF CGCs, incorporating two flexible (MIL-53(Al) and MIL-118) and one rigid (UL-MOF-1) MOF within a ZIF-62 glass matrix. Specifically, variable-temperature powder X-ray diffraction data and thermomechanical analysis show the suppression of thermal expansivity in each of these three crystalline MOFs when suspended within a ZIF-62 glass matrix. In particular, for the two flexible frameworks, the average volumetric thermal expansion (ß) was found to be near-zero in the crystal-glass composite. These results provide a route to engineering thermal expansivity in stimuli-responsive MOF glass composites.

4.
Int J Mol Sci ; 22(23)2021 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-34884800

RESUMO

Many psychoactive compounds have been shown to primarily interact with high-affinity and low-capacity solute carrier 6 (SLC6) monoamine transporters for norepinephrine (NET; norepinephrine transporter), dopamine (DAT; dopamine transporter) and serotonin (SERT; serotonin transporter). Previous studies indicate an overlap between the inhibitory capacities of substances at SLC6 and SLC22 human organic cation transporters (SLC22A1-3; hOCT1-3) and the human plasma membrane monoamine transporter (SLC29A4; hPMAT), which can be classified as high-capacity, low-affinity monoamine transporters. However, interactions between central nervous system active substances, the OCTs, and the functionally-related PMAT have largely been understudied. Herein, we report data from 17 psychoactive substances interacting with the SLC6 monoamine transporters, concerning their potential to interact with the human OCT isoforms and hPMAT by utilizing radiotracer-based in vitro uptake inhibition assays at stably expressing human embryonic kidney 293 cells (HEK293) cells. Many compounds inhibit substrate uptake by hOCT1 and hOCT2 in the low micromolar range, whereas only a few substances interact with hOCT3 and hPMAT. Interestingly, methylphenidate and ketamine selectively interact with hOCT1 or hOCT2, respectively. Additionally, 3,4-methylenedioxymethamphetamine (MDMA) is a potent inhibitor of hOCT1 and 2 and hPMAT. Enantiospecific differences of R- and S-α-pyrrolidinovalerophenone (R- and S-α-PVP) and R- and S-citalopram and the effects of aromatic substituents are explored. Our results highlight the significance of investigating drug interactions with hOCTs and hPMAT, due to their role in regulating monoamine concentrations and xenobiotic clearance.


Assuntos
Proteínas de Transporte de Nucleosídeo Equilibrativas/metabolismo , Proteínas da Membrana Plasmática de Transporte de GABA/metabolismo , Fatores de Transcrição de Octâmero/metabolismo , Transportador 1 de Cátions Orgânicos/metabolismo , Transportador 2 de Cátion Orgânico/metabolismo , Psicotrópicos/farmacologia , 3,4-Metilenodioxianfetamina/análogos & derivados , 3,4-Metilenodioxianfetamina/farmacologia , Linhagem Celular , Sistema Nervoso Central/efeitos dos fármacos , Citalopram/farmacologia , Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Células HEK293 , Humanos , Pirrolidinas/farmacologia , Proteínas da Membrana Plasmática de Transporte de Serotonina/metabolismo , Proteínas Vesiculares de Transporte de Monoamina/metabolismo
5.
Adv Funct Mater ; 30(44)2020 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-34211358

RESUMO

3-dimensional (3D) laboratory tissue cultures have emerged as an alternative to traditional 2-dimensional (2D) culture systems that do not recapitulate native cell behavior. The discrepancy between in vivo and in vitro tissue-cell-molecular responses impedes understanding of human physiology in general and creates roadblocks for the discovery of therapeutic solutions. Two parallel approaches have emerged for the design of 3D culture systems. The first is biomedical engineering methodology, including bioengineered materials, bioprinting, microfluidics and bioreactors, used alone or in combination, to mimic the microenvironments of native tissues. The second approach is organoid technology, in which stem cells are exposed to chemical and/or biological cues to activate differentiation programs that are reminiscent of human (prenatal) development. This review article describes recent technological advances in engineering 3D cultures that more closely resemble the human brain. The contributions of in vitro 3D tissue culture systems to new insights in neurophysiology, neurological diseases and regenerative medicine are highlighted. Perspectives on designing improved tissue models of the human brain are offered, focusing on an integrative approach merging biomedical engineering tools with organoid biology.

6.
BMC Genomics ; 20(1): 44, 2019 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-30646842

RESUMO

Following the publication of this article [1], the authors informed us of the following typographical errors in the Results section (the changes are marked in bold).

7.
BMC Genomics ; 19(1): 563, 2018 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-30064353

RESUMO

BACKGROUND: Chromatin accessibility profiling assays such as ATAC-seq and DNase1-seq offer the opportunity to rapidly characterize the regulatory state of the genome at a single nucleotide resolution. Optimization of molecular protocols has enabled the molecular biologist to produce next-generation sequencing libraries in several hours, leaving the analysis of sequencing data as the primary obstacle to wide-scale deployment of accessibility profiling assays. To address this obstacle we have developed an optimized and efficient pipeline for the analysis of ATAC-seq and DNase1-seq data. RESULTS: We executed a multi-dimensional grid-search on the NIH Biowulf supercomputing cluster to assess the impact of parameter selection on biological reproducibility and ChIP-seq recovery by analyzing 4560 pipeline configurations. Our analysis improved ChIP-seq recovery by 15% for ATAC-seq and 3% for DNase1-seq and determined that PCR duplicate removal improves biological reproducibility by 36% without significant costs in footprinting transcription factors. Our analyses of down sampled reads identified a point of diminishing returns for increased library sequencing depth, with 95% of the ChIP-seq data of a 200 million read footprinting library recovered by 160 million reads. CONCLUSIONS: We present optimized ATAC-seq and DNase-seq pipelines in both Snakemake and bash formats as well as optimal sequencing depths for ATAC-seq and DNase-seq projects. The optimized ATAC-seq and DNase1-seq analysis pipelines, parameters, and ground-truth ChIP-seq datasets have been made available for deployment and future algorithmic profiling.


Assuntos
Biologia Computacional/métodos , Desoxirribonuclease I/metabolismo , Análise de Sequência de DNA/métodos , Imunoprecipitação da Cromatina , Biblioteca Genômica , Sequenciamento de Nucleotídeos em Larga Escala , Reprodutibilidade dos Testes , Fatores de Transcrição/metabolismo
8.
Osteoarthritis Cartilage ; 26(3): 350-355, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29129650

RESUMO

OBJECTIVE: To quantify the current national burden of opioids for osteoarthritis (OA) pain in Australia in terms of number of dispensed opioid prescriptions and associated costs, and to forecast the likely burden to the year 2030/31. DESIGN: Epidemiological modelling. METHODS: Published data were obtained on rates of opioid prescribing for people with OA and national OA prevalence projections. Trends in opioid dispensing from 2006 to 2016, and average costs for common opioid subtypes were obtained from the Pharmaceutical Benefits Scheme and Medicare Australia Statistics. Using these inputs, a model was developed to estimate the likely number of dispensed opioid prescriptions and costs to the public healthcare system by 2030/31. RESULTS: In 2015/16, an estimated 1.1 million opioid prescriptions were dispensed in Australia for 403,954 people with OA (of a total 2.2 million Australians with OA). Based on recent dispensing trends and OA prevalence projections, the number of dispensed opioid prescriptions is expected to nearly triple to 3,032,332 by 2030/31, for an estimated 562,610 people with OA. The estimated cost to the Australian healthcare system was $AUD25.2 million in 2015/16, rising to $AUD72.4 million by 2030/31. CONCLUSION: OA-related opioid dispensing and associated costs are set to increase substantially in Australia from 2015/16 to 2030/31. Use of opioids for OA pain is concerning given joint disease chronicity and the risk of adverse events, particularly among older people. These projections represent a conservative estimate of the full financial burden given additional costs associated with opioid-related harms and out-of-pocket costs borne by patients.


Assuntos
Analgésicos Opioides/uso terapêutico , Osteoartrite/tratamento farmacológico , Analgésicos Opioides/economia , Austrália/epidemiologia , Dor Crônica/tratamento farmacológico , Dor Crônica/economia , Dor Crônica/epidemiologia , Dor Crônica/etiologia , Efeitos Psicossociais da Doença , Custos de Medicamentos/tendências , Prescrições de Medicamentos/estatística & dados numéricos , Previsões , Custos de Cuidados de Saúde/tendências , Humanos , Programas Nacionais de Saúde/economia , Programas Nacionais de Saúde/estatística & dados numéricos , Programas Nacionais de Saúde/tendências , Osteoartrite/complicações , Osteoartrite/economia , Osteoartrite/epidemiologia
9.
Nature ; 483(7388): 222-6, 2012 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-22388814

RESUMO

Cognitive decline is a debilitating feature of most neurodegenerative diseases of the central nervous system, including Alzheimer's disease. The causes leading to such impairment are only poorly understood and effective treatments are slow to emerge. Here we show that cognitive capacities in the neurodegenerating brain are constrained by an epigenetic blockade of gene transcription that is potentially reversible. This blockade is mediated by histone deacetylase 2, which is increased by Alzheimer's-disease-related neurotoxic insults in vitro, in two mouse models of neurodegeneration and in patients with Alzheimer's disease. Histone deacetylase 2 associates with and reduces the histone acetylation of genes important for learning and memory, which show a concomitant decrease in expression. Importantly, reversing the build-up of histone deacetylase 2 by short-hairpin-RNA-mediated knockdown unlocks the repression of these genes, reinstates structural and synaptic plasticity, and abolishes neurodegeneration-associated memory impairments. These findings advocate for the development of selective inhibitors of histone deacetylase 2 and suggest that cognitive capacities following neurodegeneration are not entirely lost, but merely impaired by this epigenetic blockade.


Assuntos
Encéfalo/fisiopatologia , Epigênese Genética , Histona Desacetilase 2/genética , Transtornos da Memória/genética , Transtornos da Memória/fisiopatologia , Doenças Neurodegenerativas/genética , Doenças Neurodegenerativas/fisiopatologia , Acetilação/efeitos dos fármacos , Doença de Alzheimer/complicações , Doença de Alzheimer/genética , Doença de Alzheimer/fisiopatologia , Peptídeos beta-Amiloides/toxicidade , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Modelos Animais de Doenças , Epigênese Genética/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Histona Desacetilase 2/deficiência , Histona Desacetilase 2/metabolismo , Histonas/metabolismo , Humanos , Peróxido de Hidrogênio/toxicidade , Transtornos da Memória/complicações , Camundongos , Doenças Neurodegenerativas/complicações , Plasticidade Neuronal/efeitos dos fármacos , Plasticidade Neuronal/genética , Fragmentos de Peptídeos/toxicidade , Fosforilação/efeitos dos fármacos , Regiões Promotoras Genéticas/efeitos dos fármacos , Regiões Promotoras Genéticas/genética , RNA Polimerase II/metabolismo , Receptores de Glucocorticoides/metabolismo
10.
Proc Natl Acad Sci U S A ; 111(4): 1491-6, 2014 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-24434558

RESUMO

Aire induces the expression of a large set of autoantigen genes in the thymus, driving immunological tolerance in maturing T cells. To determine the full spectrum of molecular mechanisms underlying the Aire transactivation function, we screened an AIRE-dependent gene-expression system with a genome-scale lentiviral shRNA library, targeting factors associated with chromatin architecture/function, transcription, and mRNA processing. Fifty-one functional allies were identified, with a preponderance of factors that impact transcriptional elongation compared with initiation, in particular members of the positive transcription elongation factor b (P-TEFb) involved in the release of "paused" RNA polymerases (CCNT2 and HEXIM1); mRNA processing and polyadenylation factors were also highlighted (HNRNPL/F, SFRS1, SFRS3, and CLP1). Aire's functional allies were validated on transfected and endogenous target genes, including the generation of lentigenic knockdown (KD) mice. We uncovered the effect of the splicing factor Hnrnpl on Aire-induced transcription. Transcripts sensitive to the P-TEFb inhibitor flavopiridol were reduced by Hnrnpl knockdown in thymic epithelial cells, independently of their dependence on Aire, therefore indicating a general effect of Hnrnpl on RNA elongation. This conclusion was substantiated by demonstration of HNRNPL interactions with P-TEFb components (CDK9, CCNT2, HEXIM1, and the small 7SK RNA). Aire-containing complexes include 7SK RNA, the latter interaction disrupted by HNRNPL knockdown, suggesting that HNRNPL may partake in delivering inactive P-TEFb to Aire. Thus, these results indicate that mRNA processing factors cooperate with Aire to release stalled polymerases and to activate ectopic expression of autoantigen genes in the thymus.


Assuntos
Ribonucleoproteínas Nucleares Heterogêneas/fisiologia , Interferência de RNA , Fatores de Transcrição/genética , Transcrição Gênica/fisiologia , Animais , Linhagem Celular , Técnicas de Silenciamento de Genes , Ribonucleoproteínas Nucleares Heterogêneas/genética , Humanos , Camundongos , Fatores de Transcrição/fisiologia , Proteína AIRE
11.
Health Educ Res ; 31(1): 70-81, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26612050

RESUMO

Health literacy is 'the capacity to obtain, process and understand basic health information and services needed to make appropriate health decisions'. Although numerous studies show a link between health literacy and clinical outcomes, little research has examined the association of health literacy with oral health. No large-scale studies have assessed these relationships among American Indians, a population at risk for limited health literacy and oral health problems. This analysis was conducted as part of a clinical trial aimed at reducing dental decay among preschoolers in the Navajo Nation Head Start program. Using baseline data for 1016 parent-child dyads, we examined the association of parental health literacy with parents' oral health knowledge, attitudes, and behavior, as well as indicators of parental and pediatric oral health. More limited health literacy was associated with lower levels of oral health knowledge, more negative oral health attitudes, and lower levels of adherence to recommended oral health behavior. Parents with more limited health literacy also had significantly worse oral health status (OHS) and reported their children to have significantly worse oral health-related quality of life. These results highlight the importance of oral health promotion interventions that are sensitive to the needs of participants with limited health literacy.


Assuntos
Saúde da Criança , Letramento em Saúde , Indígenas Norte-Americanos , Saúde Bucal/educação , Pais/educação , Adulto , Idoso , Idoso de 80 Anos ou mais , Pré-Escolar , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
12.
Bioorg Med Chem Lett ; 25(12): 2594-8, 2015 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-25958245

RESUMO

A new series of potent inhibitors of cellular lipid uptake from HDL particles mediated by scavenger receptor, class B, type I (SR-BI) was identified. The series was identified via a high-throughput screen of the National Institutes of Health Molecular Libraries Small Molecule Repository (NIH MLSMR) that measured the transfer of the fluorescent lipid DiI from HDL particles to CHO cells overexpressing SR-BI. The series is characterized by a linear peptidomimetic scaffold with two adjacent amide groups, as well as an aryl-substituted heterocycle. Analogs of the initial hit were rapidly prepared via Ugi 4-component reaction, and select enantiopure compounds were prepared via a stepwise sequence. Structure-activity relationship (SAR) studies suggest an oxygenated arene is preferred at the western end of the molecule, as well as highly lipophilic substituents on the central and eastern nitrogens. Compound 5e, with (R)-stereochemistry at the central carbon, was designated as probe ML279. Mechanistic studies indicate that ML279 stabilizes the interaction of HDL particles with SR-BI, and its effect is reversible. It shows good potency (IC50=17 nM), is non-toxic, plasma stable, and has improved solubility over our alternative probe ML278.


Assuntos
Alanina/análogos & derivados , Antígenos CD36/antagonistas & inibidores , Furanos/química , Compostos Heterocíclicos/química , Tetrazóis/química , Alanina/síntese química , Alanina/química , Alanina/metabolismo , Animais , Antígenos CD36/genética , Antígenos CD36/metabolismo , Células CHO , Cricetinae , Cricetulus , Avaliação Pré-Clínica de Medicamentos , Lipoproteínas HDL/metabolismo , Ligação Proteica , Relação Estrutura-Atividade , Tetrazóis/síntese química , Tetrazóis/metabolismo
13.
Bioorg Med Chem Lett ; 25(10): 2100-5, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25900219

RESUMO

We report a new series of 8-membered benzo-fused lactams that inhibit cellular lipid uptake from HDL particles mediated by Scavenger Receptor, Class B, Type I (SR-BI). The series was identified via a high-throughput screen of the National Institutes of Health Molecular Libraries Small Molecule Repository (NIH MLSMR), measuring the transfer of the fluorescent lipid DiI from HDL particles to CHO cells overexpressing SR-BI. The series is part of a previously reported diversity-oriented synthesis (DOS) library prepared via a build-couple-pair approach. Detailed structure-activity relationship (SAR) studies were performed with a selection of the original library, as well as additional analogs prepared via solution phase synthesis. These studies demonstrate that the orientation of the substituents on the aliphatic ring have a critical effect on activity. Additionally, a lipophilic group is required at the western end of the molecule, and a northern hydroxyl group and a southern sulfonamide substituent also proved to be optimal. Compound 2p was found to possess a superior combination of potency (av IC50=0.10µM) and solubility (79µM in PBS), and it was designated as probe ML312.


Assuntos
Antígenos CD36/antagonistas & inibidores , Lactamas/farmacologia , Metabolismo dos Lipídeos , Animais , Antígenos CD36/fisiologia , Humanos , Lactamas/química , Relação Estrutura-Atividade
14.
Nature ; 459(7243): 55-60, 2009 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-19424149

RESUMO

Chromatin modifications, especially histone-tail acetylation, have been implicated in memory formation. Increased histone-tail acetylation induced by inhibitors of histone deacetylases (HDACis) facilitates learning and memory in wild-type mice as well as in mouse models of neurodegeneration. Harnessing the therapeutic potential of HDACis requires knowledge of the specific HDAC family member(s) linked to cognitive enhancement. Here we show that neuron-specific overexpression of HDAC2, but not that of HDAC1, decreased dendritic spine density, synapse number, synaptic plasticity and memory formation. Conversely, Hdac2 deficiency resulted in increased synapse number and memory facilitation, similar to chronic treatment with HDACis in mice. Notably, reduced synapse number and learning impairment of HDAC2-overexpressing mice were ameliorated by chronic treatment with HDACis. Correspondingly, treatment with HDACis failed to further facilitate memory formation in Hdac2-deficient mice. Furthermore, analysis of promoter occupancy revealed an association of HDAC2 with the promoters of genes implicated in synaptic plasticity and memory formation. Taken together, our results suggest that HDAC2 functions in modulating synaptic plasticity and long-lasting changes of neural circuits, which in turn negatively regulates learning and memory. These observations encourage the development and testing of HDAC2-selective inhibitors for human diseases associated with memory impairment.


Assuntos
Sinapses Elétricas/fisiologia , Histona Desacetilases/metabolismo , Memória/fisiologia , Proteínas Repressoras/metabolismo , Animais , Butiratos/farmacologia , Espinhas Dendríticas/fisiologia , Feminino , Regulação da Expressão Gênica , Hipocampo/metabolismo , Histona Desacetilase 1 , Histona Desacetilase 2 , Inibidores de Histona Desacetilases , Histona Desacetilases/deficiência , Histona Desacetilases/genética , Ácidos Hidroxâmicos/farmacologia , Aprendizagem/efeitos dos fármacos , Masculino , Memória/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neurônios/metabolismo , Regiões Promotoras Genéticas/genética , Proteínas Repressoras/antagonistas & inibidores , Proteínas Repressoras/genética , Sódio/farmacologia , Vorinostat
15.
Proc Natl Acad Sci U S A ; 108(30): 12243-8, 2011 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-21746906

RESUMO

The HDL receptor, scavenger receptor, class B, type I (SR-BI), is a homooligomeric cell surface glycoprotein that controls HDL structure and metabolism by mediating the cellular selective uptake of lipids, mainly cholesteryl esters, from HDL. The mechanism underlying SR-BI-mediated lipid transfer, which differs from classic receptor-mediated endocytosis, involves a two-step process (binding followed by lipid transport) that is poorly understood. Our previous structure/activity analysis of the small-molecule inhibitor blocker of lipid transport 1 (BLT-1), which potently (IC(50) âˆ¼ 50 nM) blocks SR-BI-mediated lipid transport, established that the sulfur in BLT-1's thiosemicarbazone moiety was essential for activity. Here we show that BLT-1 is an irreversible inhibitor of SR-BI, raising the possibility that cysteine(s) in SR-BI interact with BLT-1. Mass spectrometric analysis of purified SR-BI showed two of its six exoplasmic cysteines have free thiol groups (Cys251 and Cys384). Converting Cys384 (but not Cys251) to serine resulted in complete BLT-1 insensitivity, establishing that the unique molecular target of BLT-1 inhibition of cellular SR-BI dependent lipid transport is SR-BI itself. The C384S substitution reduced the receptor's intrinsic lipid uptake activity by approximately 60% without dramatically altering its surface expression, homooligomerization, or HDL binding. Thus, a small-molecule screening approach identified a key residue in SR-BI involved in lipid transport, providing a powerful springboard into the analyses of the structure and mechanism of SR-BI, and highlighting the power of this approach for such analyses.


Assuntos
Receptores Depuradores Classe B/química , Substituição de Aminoácidos , Animais , Sítios de Ligação , Transporte Biológico Ativo , Células COS , Chlorocebus aethiops , Ciclopentanos/farmacologia , Cisteína/química , Humanos , Técnicas In Vitro , Metabolismo dos Lipídeos , Lipoproteínas HDL/metabolismo , Espectrometria de Massas , Camundongos , Modelos Moleculares , Mutagênese Sítio-Dirigida , Proteínas Mutantes/antagonistas & inibidores , Proteínas Mutantes/química , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Proteínas Recombinantes/antagonistas & inibidores , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Receptores Depuradores Classe B/antagonistas & inibidores , Receptores Depuradores Classe B/genética , Receptores Depuradores Classe B/metabolismo , Tiossemicarbazonas/farmacologia
16.
Res Sq ; 2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-38978567

RESUMO

Identifying cell types and states remains a time-consuming, error-prone challenge for spatial biology. While deep learning is increasingly used, it is difficult to generalize due to variability at the level of cells, neighborhoods, and niches in health and disease. To address this, we developed TACIT, an unsupervised algorithm for cell annotation using predefined signatures that operates without training data. TACIT uses unbiased thresholding to distinguish positive cells from background, focusing on relevant markers to identify ambiguous cells in multiomic assays. Using five datasets (5,000,000-cells; 51-cell types) from three niches (brain, intestine, gland), TACIT outperformed existing unsupervised methods in accuracy and scalability. Integrating TACIT-identified cell types with a novel Shiny app revealed new phenotypes in two inflammatory gland diseases. Finally, using combined spatial transcriptomics and proteomics, we discovered under- and overrepresented immune cell types and states in regions of interest, suggesting multimodality is essential for translating spatial biology to clinical applications.

17.
Res Sq ; 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38196575

RESUMO

Sjögren's Disease (SjD) is a systemic autoimmune disease without a clear etiology or effective therapy. Utilizing unbiased single-cell and spatial transcriptomics to analyze human minor salivary glands in health and disease we developed a comprehensive understanding of the cellular landscape of healthy salivary glands and how that landscape changes in SjD patients. We identified novel seromucous acinar cell types and identified a population of PRR4+CST3+WFDC2- seromucous acinar cells that are particularly targeted in SjD. Notably, GZMK+CD8 T cells, enriched in SjD, exhibited a cytotoxic phenotype and were physically associated with immune-engaged epithelial cells in disease. These findings shed light on the immune response's impact on transitioning acinar cells with high levels of secretion and explain the loss of this specific cell population in SjD. This study explores the complex interplay of varied cell types in the salivary glands and their role in the pathology of Sjögren's Disease.

18.
Biomed Pharmacother ; 165: 115065, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37406506

RESUMO

Ionizable cationic lipids (ICLs) play an essential role in the effectiveness of lipid nanoparticles (LNPs) for delivery of mRNA therapeutics and vaccines; therefore, critical evaluations of their biological performance would extend the existing knowledge in the field. In the present study, we examined the effects of the three clinically-approved ICLs, Dlin-MC3-DMA, ALC-0315 and SM-102, as well as DODAP, on the in vitro and in vivo performance of LNPs for mRNA delivery and vaccine efficacy. mRNA-LNPs containing these lipids were successfully prepared, which were all found to be very similar in their physicochemical properties and mRNA encapsulation efficiencies. Furthermore, the results of the in vitro studies indicated that these mRNA-LNPs were efficiently taken up by immortalized and primary immune cells with comparable efficiency; however, SM-102-based LNPs were superior in inducing protein expression and antigen-specific T cell proliferation. In contrast, in vivo studies revealed that LNPs containing ALC-0315 and SM-102 yielded almost identical protein expression levels in zebrafish embryos, which were significantly higher than Dlin-MC3-DMA-based LNPs. Additionally, a mouse immunization study demonstrated that a single-dose subcutaneous administration of the mRNA-LNPs resulted in a high production of intracellular cytokines by antigen-specific T cells, but no significant differences among the three clinically-approved ICLs were observed, suggesting a weak correlation between in vitro and in vivo outcomes. This study provides strong evidence that ICLs modulate the performance of mRNA-LNPs and that in vitro data does not adequately predict their behavior in vivo.


Assuntos
Lipídeos , Nanopartículas , Animais , Camundongos , Lipídeos/química , RNA Mensageiro , Eficácia de Vacinas , Peixe-Zebra/metabolismo , Transfecção , Nanopartículas/química , RNA Interferente Pequeno/genética
19.
Cell Death Dis ; 14(8): 496, 2023 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-37537168

RESUMO

Traumatic Brain injury-induced disturbances in mitochondrial fission-and-fusion dynamics have been linked to the onset and propagation of neuroinflammation and neurodegeneration. However, cell-type-specific contributions and crosstalk between neurons, microglia, and astrocytes in mitochondria-driven neurodegeneration after brain injury remain undefined. We developed a human three-dimensional in vitro triculture tissue model of a contusion injury composed of neurons, microglia, and astrocytes and examined the contributions of mitochondrial dysregulation to neuroinflammation and progression of injury-induced neurodegeneration. Pharmacological studies presented here suggest that fragmented mitochondria released by microglia are a key contributor to secondary neuronal damage progression after contusion injury, a pathway that requires astrocyte-microglia crosstalk. Controlling mitochondrial dysfunction thus offers an exciting option for developing therapies for TBI patients.


Assuntos
Lesões Encefálicas Traumáticas , Contusões , Humanos , Doenças Neuroinflamatórias , Inflamação/metabolismo , Encéfalo/metabolismo , Lesões Encefálicas Traumáticas/metabolismo , Contusões/metabolismo , Mitocôndrias/metabolismo , Microglia/metabolismo , Astrócitos/metabolismo
20.
medRxiv ; 2023 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-37662351

RESUMO

Objectives: Inflammatory cytokines that signal through the JAK- STAT pathway, especially interferons (IFNs), are implicated in Sjögren's Disease (SjD). Although inhibition of JAKs is effective in other autoimmune diseases, a systematic investigation of IFN-JAK-STAT signaling and effect of JAK inhibitor (JAKi) therapy in SjD-affected human tissues has not been reported. Methods: Human minor salivary glands (MSGs) and peripheral blood mononuclear cells (PBMCs) were investigated using bulk or single cell (sc) RNA sequencing (RNAseq), immunofluorescence microscopy (IF), and flow cytometry. Ex vivo culture assays on PBMCs and primary salivary gland epithelial cell (pSGEC) lines were performed to model changes in target tissues before and after JAKi. Results: RNAseq and IF showed activated JAK-STAT pathway in SjD MSGs. Elevated IFN-stimulated gene (ISGs) expression associated with clinical variables (e.g., focus scores, anti-SSA positivity). scRNAseq of MSGs exhibited cell-type specific upregulation of JAK-STAT and ISGs; PBMCs showed similar trends, including markedly upregulated ISGs in monocytes. Ex vivo studies showed elevated basal pSTAT levels in SjD MSGs and PBMCs that were corrected with JAKi. SjD-derived pSGECs exhibited higher basal ISG expressions and exaggerated responses to IFNß, which were normalized by JAKi without cytotoxicity. Conclusions: SjD patients' tissues exhibit increased expression of ISGs and activation of the JAK-STAT pathway in a cell type-dependent manner. JAKi normalizes this aberrant signaling at the tissue level and in PBMCs, suggesting a putative viable therapy for SjD, targeting both glandular and extraglandular symptoms. Predicated on these data, a Phase Ib/IIa randomized controlled trial to treat SjD with tofacitinib was initiated.

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