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1.
J Pathol ; 255(4): 343-345, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34564856

RESUMO

Distinct morphological subtypes of colorectal cancer (CRC) confer a bleak clinical outlook. In a recent issue of The Journal of Pathology, Onuma et al investigated morphological evolution of a highly fatal CRC subtype known as micropapillary cancer (MPC). This study enhances understanding of MPC biology including essential regulatory signals, cellular and multicellular phenotypes, as well as cancer behaviour. Iterative modelling in three-dimensional (3D) patient-derived CRC tissue-originated spheroids (CTOSs) revealed spatiotemporal oscillations of Rho-ROCK hyperactivity underlying reversal of membrane polarity and suppression of lumen formation during development of multicellular MPC morphology. Corroborative studies in CTOSs, xenografts, and archival human CRCs confirm human disease relevance. Although cancer morphology has previously been considered irreversible, targeted inhibition of Rho-ROCK activity restored membrane polarity, lumenized multicellular assembly, and suppressed MPC morphology in 3D CTOS cultures and xenografts. Collectively, the study identifies molecular, biophysical, and multicellular mechanisms implicated in morphological evolution of micropapillary CRC. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.


Assuntos
Adenocarcinoma de Pulmão , Carcinoma Papilar , Neoplasias Colorretais , Neoplasias Pulmonares , Polaridade Celular , Humanos
2.
J Pathol ; 251(3): 310-322, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32315081

RESUMO

The phenotypic spectrum of colorectal cancer (CRC) is remarkably diverse, with seemingly endless variations in cell shape, mitotic figures and multicellular configurations. Despite this morphological complexity, histological grading of collective phenotype patterns provides robust prognostic stratification in CRC. Although mechanistic understanding is incomplete, previous studies have shown that the cortical protein ezrin controls diversification of cell shape, mitotic figure geometry and multicellular architecture, in 3D organotypic CRC cultures. Because ezrin is a substrate of Src tyrosine kinase that is frequently overexpressed in CRC, we investigated Src regulation of ezrin and morphogenic growth in 3D CRC cultures. Here we show that Src perturbations disrupt CRC epithelial spatial organisation. Aberrant Src activity suppresses formation of the cortical ezrin cap that anchors interphase centrosomes. In CRC cells with a normal centrosome number, these events lead to mitotic spindle misorientation, perturbation of cell cleavage, abnormal epithelial stratification, apical membrane misalignment, multilumen formation and evolution of cribriform multicellular morphology, a feature of low-grade cancer. In isogenic CRC cells with centrosome amplification, aberrant Src signalling promotes multipolar mitotic spindle formation, pleomorphism and morphological features of high-grade cancer. Translational studies in archival human CRC revealed associations between Src intensity, multipolar mitotic spindle frequency and high-grade cancer morphology. Collectively, our study reveals Src regulation of CRC morphogenic growth via ezrin-centrosome engagement and uncovers combined perturbations underlying transition to high-grade CRC morphology. © 2020 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.


Assuntos
Centrossomo/enzimologia , Neoplasias Colorretais/enzimologia , Proteínas do Citoesqueleto/metabolismo , Mitose , Quinases da Família src/metabolismo , Células CACO-2 , Centrossomo/patologia , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Proteínas do Citoesqueleto/genética , Quinase 1 de Adesão Focal/genética , Quinase 1 de Adesão Focal/metabolismo , Células HCT116 , Humanos , Gradação de Tumores , PTEN Fosfo-Hidrolase/genética , PTEN Fosfo-Hidrolase/metabolismo , Transdução de Sinais , Quinases da Família src/genética
3.
Am J Pathol ; 188(9): 1936-1948, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30028958

RESUMO

Colorectal cancer (CRC) diagnosis and prognostic stratification are based on histopathologic assessment of cell or nuclear pleomorphism, aberrant mitotic figures, altered glandular architecture, and other phenomic abnormalities. This complexity is driven by oncogenic perturbation of tightly coordinated spatiotemporal signaling to disrupt multiple scales of tissue organization. This review clarifies molecular and cellular mechanisms underlying common CRC histologic features and helps understand how the CRC genome controls core aspects of tumor aggressiveness. It further explores a spatiotemporal framework for CRC phenomics based on regulation of living cells in fundamental and organotypic model systems. The review also discusses tissue homeostasis, considers distinct classes of oncogenic perturbations, and evolution of cellular or multicellular cancer phenotypes. It further explores the molecular controls of cribriform, micropapillary, and high-grade CRC morphology in organotypic culture models and assesses relevant translational studies. In addition, the review delves into complexities of morphologic plasticity whereby a single molecular signature generates heterogeneous cancer phenotypes, and, conversely, morphologically homogeneous tumors show substantive molecular diversity. Principles outlined may aid mechanistic interpretation of omics data in a setting of cancer pathology, provide insight into CRC consensus molecular subtypes, and better define principles for CRC prognostic stratification.


Assuntos
Neoplasias Colorretais/patologia , Modelos Animais de Doenças , Técnicas de Cultura de Órgãos/métodos , Animais , Humanos
4.
Org Biomol Chem ; 17(4): 945-957, 2019 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-30629080

RESUMO

The formation of a novel trichain (TC) lipid was discovered when a cationic lipid possessing a terminal hydroxyl group and the helper lipid dioleoyl l-α-phosphatidylethanolamine (DOPE) were formulated as vesicles and stored. Importantly, the transfection efficacies of lipopolyplexes comprised of the TC lipid, a targeting peptide and DNA (LPDs) were found to be higher than when the corresponding dichain (DC) lipid was used. To explore this interesting discovery and determine if this concept can be more generally applied to improve gene delivery efficiencies, the design and synthesis of a series of novel TC cationic lipids and the corresponding DC lipids was undertaken. Transfection efficacies of the LPDs were found to be higher when using the TC lipids compared to the DC analogues, so experiments were carried out to investigate the reasons for this enhancement. Sizing experiments and transmission electron microscopy indicated that there were no major differences in the size and shape of the LPDs prepared using the TC and DC lipids, while circular dichroism spectroscopy showed that the presence of the third acyl chain did not influence the conformation of the DNA within the LPD. In contrast, small angle neutron scattering studies showed a considerable re-arrangement of lipid conformation upon formulation as LPDs, particularly of the TC lipids, while gel electrophoresis studies revealed that the use of a TC lipid in the LPD formulation resulted in enhanced DNA protection properties. Thus, the major enhancement in transfection performance of these novel TC lipids can be attributed to their ability to protect and subsequently release DNA. Importantly, the TC lipids described here highlight a valuable structural template for the generation of gene delivery vectors, based on the use of lipids with three hydrophobic chains.


Assuntos
Descoberta de Drogas , Técnicas de Transferência de Genes , Lipídeos/química , Dicroísmo Circular , Lipídeos/síntese química , Lipossomos/química , Estrutura Molecular , Tamanho da Partícula , Propriedades de Superfície
5.
J Pathol ; 244(4): 445-459, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29520890

RESUMO

Histological grading provides prognostic stratification of colorectal cancer (CRC) by scoring heterogeneous phenotypes. Features of aggressiveness include aberrant mitotic spindle configurations, chromosomal breakage, and bizarre multicellular morphology, but pathobiology is poorly understood. Protein kinase C zeta (PKCz) controls mitotic spindle dynamics, chromosome segregation, and multicellular patterns, but its role in CRC phenotype evolution remains unclear. Here, we show that PKCz couples genome segregation to multicellular morphology through control of interphase centrosome anchoring. PKCz regulates interdependent processes that control centrosome positioning. Among these, interaction between the cytoskeletal linker protein ezrin and its binding partner NHERF1 promotes the formation of a localized cue for anchoring interphase centrosomes to the cell cortex. Perturbation of these phenomena induced different outcomes in cells with single or extra centrosomes. Defective anchoring of a single centrosome promoted bipolar spindle misorientation, multi-lumen formation, and aberrant epithelial stratification. Collectively, these disturbances induce cribriform multicellular morphology that is typical of some categories of low-grade CRC. By contrast, defective anchoring of extra centrosomes promoted multipolar spindle formation, chromosomal instability (CIN), disruption of glandular morphology, and cell outgrowth across the extracellular matrix interface characteristic of aggressive, high-grade CRC. Because PKCz enhances apical NHERF1 intensity in 3D epithelial cultures, we used an immunohistochemical (IHC) assay of apical NHERF1 intensity as an indirect readout of PKCz activity in translational studies. We show that apical NHERF1 IHC intensity is inversely associated with multipolar spindle frequency and high-grade morphology in formalin-fixed human CRC samples. To conclude, defective PKCz control of interphase centrosome anchoring may underlie distinct categories of mitotic slippage that shape the development of low- or high-grade CRC phenotypes. © 2018 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.


Assuntos
Centrossomo/enzimologia , Neoplasias Colorretais/enzimologia , Interfase , Proteína Quinase C/metabolismo , Células CACO-2 , Proliferação de Células , Forma Celular , Instabilidade Cromossômica , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Proteínas do Citoesqueleto/genética , Proteínas do Citoesqueleto/metabolismo , Humanos , Gradação de Tumores , Fenótipo , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Proteína Quinase C/genética , Transdução de Sinais , Trocadores de Sódio-Hidrogênio/genética , Trocadores de Sódio-Hidrogênio/metabolismo
6.
Int J Mol Sci ; 18(10)2017 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-28937592

RESUMO

In the treatment of cancer, targeting of anticancer drugs to the tumor microenvironment is highly desirable. Not only does this imply accurate tumor targeting but also minimal drug release en route to the tumor and maximal drug release once there. Here we describe high-loading, "stealth-like" doxorubicin micelles as a pro-drug delivery system, which upon light activation, leads to burst-like doxorbicin release. Through this approach, we show precise spatiotemporal control of doxorubicin delivery to cells in vitro.


Assuntos
Doxorrubicina/administração & dosagem , Doxorrubicina/metabolismo , Sistemas de Liberação de Medicamentos , Micelas , Pró-Fármacos/química , Liberação Controlada de Fármacos , Células HeLa , Humanos , Luz
7.
Alzheimers Dement ; 12(6): 645-53, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27079753

RESUMO

Identifying accurate biomarkers of cognitive decline is essential for advancing early diagnosis and prevention therapies in Alzheimer's disease. The Alzheimer's disease DREAM Challenge was designed as a computational crowdsourced project to benchmark the current state-of-the-art in predicting cognitive outcomes in Alzheimer's disease based on high dimensional, publicly available genetic and structural imaging data. This meta-analysis failed to identify a meaningful predictor developed from either data modality, suggesting that alternate approaches should be considered for prediction of cognitive performance.


Assuntos
Doença de Alzheimer/complicações , Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/etiologia , Doença de Alzheimer/genética , Apolipoproteínas E/genética , Biomarcadores , Transtornos Cognitivos/genética , Biologia Computacional , Bases de Dados Bibliográficas/estatística & dados numéricos , Humanos , Valor Preditivo dos Testes
8.
Angew Chem Int Ed Engl ; 55(4): 1396-400, 2016 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-26661729

RESUMO

Membrane fusion results in the transport and mixing of (bio)molecules across otherwise impermeable barriers. In this communication, we describe the temporal control of targeted liposome-liposome membrane fusion and contents mixing using light as an external trigger. Our method relies on steric shielding and rapid, photoinduced deshielding of complementary fusogenic peptides tethered to opposing liposomal membranes. In an analogous approach, we were also able to demonstrate precise spatiotemporal control of liposome accumulation at cellular membranes in vitro.


Assuntos
Lipossomos , Fusão de Membrana , Membranas Artificiais , Polietilenoglicóis/química , Dicroísmo Circular , Espectrofotometria Ultravioleta
9.
Proc Natl Acad Sci U S A ; 109(28): 11088-94, 2012 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-22723346

RESUMO

A speech of then-Vice President Al Gore in 1998 created a vision for a Digital Earth, and played a role in stimulating the development of a first generation of virtual globes, typified by Google Earth, that achieved many but not all the elements of this vision. The technical achievements of Google Earth, and the functionality of this first generation of virtual globes, are reviewed against the Gore vision. Meanwhile, developments in technology continue, the era of "big data" has arrived, the general public is more and more engaged with technology through citizen science and crowd-sourcing, and advances have been made in our scientific understanding of the Earth system. However, although Google Earth stimulated progress in communicating the results of science, there continue to be substantial barriers in the public's access to science. All these factors prompt a reexamination of the initial vision of Digital Earth, and a discussion of the major elements that should be part of a next generation.


Assuntos
Geografia/métodos , Acesso à Informação , Algoritmos , Comunicação , Computadores , Planeta Terra , Software , Tecnologia
10.
BMC Bioinformatics ; 15 Suppl 6: S6, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25079297

RESUMO

Cancer is a complex disease that has proven to be difficult to understand on the single-gene level. For this reason a functional elucidation needs to take interactions among genes on a systems-level into account. In this study, we infer a colon cancer network from a large-scale gene expression data set by using the method BC3Net. We provide a structural and a functional analysis of this network and also connect its molecular interaction structure with the chromosomal locations of the genes enabling the definition of cis- and trans-interactions. Furthermore, we investigate the interaction of genes that can be found in close neighborhoods on the chromosomes to gain insight into regulatory mechanisms. To our knowledge this is the first study analyzing the genome-scale colon cancer network.


Assuntos
Neoplasias do Colo/genética , Redes Reguladoras de Genes , Neoplasias do Colo/metabolismo , Biologia Computacional , Perfilação da Expressão Gênica , Humanos , Proteínas/genética , Proteínas/metabolismo
11.
Bioorg Med Chem ; 22(22): 6459-70, 2014 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-25438770

RESUMO

A novel series of 8-amino imidazo[1,2-a]pyrazine derivatives has been developed as inhibitors of the VirB11 ATPase HP0525, a key component of the bacterial type IV secretion system. A flexible synthetic route to both 2- and 3-aryl substituted regioisomers has been developed. The resulting series of imidazo[1,2-a]pyrazines has been used to probe the structure-activity relationships of these inhibitors, which show potential as antibacterial agents.


Assuntos
Antibacterianos/química , Proteínas de Bactérias/antagonistas & inibidores , Imidazóis/química , Pirazinas/química , Antibacterianos/síntese química , Antibacterianos/metabolismo , Proteínas de Bactérias/metabolismo , Sítios de Ligação , Bactérias Gram-Negativas/metabolismo , Imidazóis/síntese química , Imidazóis/metabolismo , Cinética , Simulação de Acoplamento Molecular , Ligação Proteica , Estrutura Terciária de Proteína , Pirazinas/síntese química , Pirazinas/metabolismo , Relação Estrutura-Atividade
12.
Biomater Sci ; 12(19): 5023-5035, 2024 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-39177657

RESUMO

The composition and morphology of lipid-based nanoparticles can influence their overall in vivo behavior. Previously, we demonstrated that phase separation in liposomes composed of DSPC and a diacylglycerol lipid analogue (DOaG) drives the in vivo biodistribution towards a specific subset of endothelial cells in zebrafish embryos. In the absence of traditional targeting functionalities (e.g., antibodies, ligands), this selectivity is mediated solely by the unique liposome morphology and composition, characterized by a DOaG-rich lipid droplet within the DSPC-rich phospholipid bilayer. The phase separation is induced due to the geometry of DOaG lipid and its ability to create non-bilayer phases in lipid membranes. To investigate the underlying principles of phase separation and to optimize the liposome colloidal stability, we performed a structure-function relationship study by synthesizing a library of DOaG analogues with varying molecular properties, such as the number, length and sn-position of the acyl chains, as well as the degree of saturation or carbonyl substituents. We assessed the ability of these lipid analogues to assemble into phase-separated liposomes and studied their morphology, colloidal stability, and in vivo biodistribution in zebrafish embryos. We found that analogues containing unsaturated, medium length (C16-C18) fatty acids were required to obtain colloidally stable, phase-separated liposomes with cell-specific biodistribution patterns. Moreover, we observed that using the pure DOaG isomer, with acyl chains at the sn-1,3 positions, leads to more colloidally stable liposomes than when a mixture of sn-1,2 and sn-1,3 isomers is used. Similarly, we observed that incorporating a DOaG analogue with fatty tails shorter than DSPC, as well as PEGylation, endows liposomes with long term stability while retaining cell-selective biodistribution. Diacylglycerols are known to promote fusion, lipid polymorphism, signaling and protein recruitment on lipid membranes. In this study, we showed that diacylglycerol derivatives can induce phase separation in liposomes, unlocking the potential for cell-specific targeting in vivo. We believe that these findings can be the foundation for future use of diacylglycerols in lipid-based nanomedicines and could lead to the development of novel targeted delivery strategies.


Assuntos
Diglicerídeos , Lipossomos , Peixe-Zebra , Lipossomos/química , Diglicerídeos/química , Animais , Relação Estrutura-Atividade , Distribuição Tecidual , Embrião não Mamífero
13.
Adv Mater ; 36(6): e2310872, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37988682

RESUMO

The membrane-protein interface on lipid-based nanoparticles influences their in vivo behavior. Better understanding may evolve current drug delivery methods toward effective targeted nanomedicine. Previously, the cell-selective accumulation of a liposome formulation in vivo is demonstrated, through the recognition of lipid phase-separation by triglyceride lipases. This exemplified how liposome morphology and composition can determine nanoparticle-protein interactions. Here, the lipase-induced compositional and morphological changes of phase-separated liposomes-which bear a lipid droplet in their bilayer- are investigated, and the mechanism upon which lipases recognize and bind to the particles is unravelled. The selective lipolytic degradation of the phase-separated lipid droplet is observed, while nanoparticle integrity remains intact. Next, the Tryptophan-rich loop of the lipase is identified as the region with which the enzymes bind to the particles. This preferential binding is due to lipid packing defects induced on the liposome surface by phase separation. In parallel, the existing knowledge that phase separation leads to in vivo selectivity, is utilized to generate phase-separated mRNA-LNPs that target cell-subsets in zebrafish embryos, with subsequent mRNA delivery and protein expression. Together, these findings can expand the current knowledge on selective nanoparticle-protein communications and in vivo behavior, aspects that will assist to gain control of lipid-based nanoparticles.


Assuntos
Lipossomos , Nanopartículas , Animais , Lipossomos/química , Peixe-Zebra , Nanopartículas/química , Lipase/metabolismo , Lipídeos/química , RNA Mensageiro
14.
Mol Pharm ; 10(1): 127-41, 2013 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-23210981

RESUMO

Cationic peptide sequences, whether linear, branched, or dendritic, are widely used to condense and protect DNA in both polyplex and lipopolyplex gene delivery vectors. How these peptides behave within these particles and the consequences this has on transfection efficiency remain poorly understood. We have compared, in parallel, a complete series of cationic peptides, both branched and linear, coformulated with plasmid DNA to give polyplexes, or with plasmid DNA and the cationic lipid, DOTMA, mixed with 50% of the neutral helper lipid, DOPE, to give lipopolyplexes, and correlated the transfection efficiencies of these complexes to their biophysical properties. Lipopolyplexes formulated from branched Arg-rich peptides, or linear Lys-rich peptides, show the best transfection efficiencies in an alveolar epithelial cell line, with His-rich peptides being relatively ineffective. The majority of the biophysical studies (circular dichroism, dynamic light scattering, zeta potential, small angle neutron scattering, and gel band shift assay) indicated that all of the formulations were similar in size, surface charge, and lipid bilayer structure, and longer cationic sequences, in general, gave better transfection efficiencies. Whereas lipopolyplexes formulated from branched Arg-containing peptides were more effective than those formulated from linear Arg-containing sequences, the reverse was true for Lys-containing sequences, which may be related to differences in DNA condensation between Arg-rich and Lys-rich peptides observed in the CD studies.


Assuntos
Vetores Genéticos/administração & dosagem , Vetores Genéticos/genética , Lipídeos/administração & dosagem , Lipídeos/genética , Peptídeos/administração & dosagem , Peptídeos/genética , Cátions/administração & dosagem , Cátions/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Química Farmacêutica/métodos , Dicroísmo Circular/métodos , DNA/administração & dosagem , DNA/química , DNA/genética , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Técnicas de Transferência de Genes , Vetores Genéticos/química , Humanos , Lipídeos/química , Tamanho da Partícula , Peptídeos/química , Plasmídeos/administração & dosagem , Plasmídeos/química , Plasmídeos/genética , Alvéolos Pulmonares/efeitos dos fármacos , Alvéolos Pulmonares/metabolismo , Mucosa Respiratória/efeitos dos fármacos , Mucosa Respiratória/metabolismo , Transfecção/métodos
15.
Biomater Sci ; 11(9): 3335-3353, 2023 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-36960608

RESUMO

Lipopolyplexes (LPDs) are of considerable interest for use as gene delivery vehicles. Here LPDs have been prepared from cationic vesicles (composed of a 1 : 1 molar ratio of DOTMA with the neutral helper lipid, DOPE), singly branched cationic peptides and plasmid DNA. All peptides contained a linker sequence (cleaved by endosomal furin) attached to a targeting sequence selected to bind human airway epithelial cells and mediate gene delivery. The current study investigates the effects of novel Arg-containing cationic peptide sequences on the biophysical and transfection properties of LPDs. Mixed His/Arg cationic peptides were of particular interest, as these sequences have not been previously used in LPD formulations. Lengthening the number of cationic residues in a homopolymer from 6 to 12 in each branch reduced transfection using LPDs, most likely due to increased DNA compaction hindering the release of pDNA within the target cell. Furthermore, LPDs containing mixed Arg-containing peptides, particularly an alternating Arg/His sequence exhibited an increase in transfection, probably because of their optimal ability to complex and subsequently release pDNA. To confer stability in serum, LPDs were prepared in 0.12 M sodium chloride solution (as opposed to the more commonly used water) yielding multilamellar LPDs with very high levels of size reproducibility and DNA protection, especially when compared to the (unilamellar) LPDs formed in water. Significantly for the clinical applications of the LPDs, those prepared in the presence of sodium chloride retained high levels of transfection in the presence of media supplemented with fetal bovine serum. This work therefore represents a significant advance for the optimisation of LPD formulation for gene delivery, under physiologically relevant conditions, in vivo.


Assuntos
Peptídeos , Cloreto de Sódio , Humanos , Reprodutibilidade dos Testes , Transfecção , Peptídeos/química , DNA/química , Plasmídeos/genética , Lipossomos/química
16.
Adv Healthc Mater ; 12(10): e2202709, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36565694

RESUMO

Plasma lipid transport and metabolism are essential to ensure correct cellular function throughout the body. Dynamically regulated in time and space, the well-characterized mechanisms underpinning plasma lipid transport and metabolism offers an enticing, but as yet underexplored, rationale to design synthetic lipid nanoparticles with inherent cell/tissue selectivity. Herein, a systemically administered liposome formulation, composed of just two lipids, that is capable of hijacking a triglyceride lipase-mediated lipid transport pathway resulting in liposome recognition and uptake within specific endothelial cell subsets is described. In the absence of targeting ligands, liposome-lipase interactions are mediated by a unique, phase-separated ("parachute") liposome morphology. Within the embryonic zebrafish, selective liposome accumulation is observed at the developing blood-brain barrier. In mice, extensive liposome accumulation within the liver and spleen - which is reduced, but not eliminated, following small molecule lipase inhibition - supports a role for endothelial lipase but highlights these liposomes are also subject to significant "off-target" by reticuloendothelial system organs. Overall, these compositionally simplistic liposomes offer new insights into the discovery and design of lipid-based nanoparticles that can exploit endogenous lipid transport and metabolism pathways to achieve cell selective targeting in vivo.


Assuntos
Lipossomos , Peixe-Zebra , Camundongos , Animais , Peixe-Zebra/metabolismo , Células Endoteliais/metabolismo , Lipase , Lipídeos , Lipoproteínas
17.
Adv Mater ; 34(16): e2201095, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35218106

RESUMO

Lipid nanoparticles (LNPs) are the leading nonviral technologies for the delivery of exogenous RNA to target cells in vivo. As systemic delivery platforms, these technologies are exemplified by Onpattro, an approved LNP-based RNA interference therapy, administered intravenously and targeted to parenchymal liver cells. The discovery of systemically administered LNP technologies capable of preferential RNA delivery beyond hepatocytes has, however, proven more challenging. Here, preceded by comprehensive mechanistic understanding of in vivo nanoparticle biodistribution and bodily clearance, an LNP-based messenger RNA (mRNA) delivery platform is rationally designed to preferentially target the hepatic reticuloendothelial system (RES). Evaluated in embryonic zebrafish, validated in mice, and directly compared to LNP-mRNA systems based on the lipid composition of Onpattro, RES-targeted LNPs significantly enhance mRNA expression both globally within the liver and specifically within hepatic RES cell types. Hepatic RES targeting requires just a single lipid change within the formulation of Onpattro to switch LNP surface charge from neutral to anionic. This technology not only provides new opportunities to treat liver-specific and systemic diseases in which RES cell types play a key role but, more importantly, exemplifies that rational design of advanced RNA therapies must be preceded by a robust understanding of the dominant nano-biointeractions involved.


Assuntos
Lipídeos , Nanopartículas , Animais , Lipossomos , Fígado/metabolismo , Camundongos , Sistema Fagocitário Mononuclear/metabolismo , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/genética , Distribuição Tecidual , Peixe-Zebra
18.
Eur J Nucl Med Mol Imaging ; 38(4): 656-62, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21161213

RESUMO

PURPOSE: The aim of the study was to compare the pre-operative metabolic tumour length on FDG PET/CT with the resected pathological specimen in patients with oesophageal cancer. METHODS: All patients diagnosed with oesophageal carcinoma who had undergone staging PET/CT imaging between the period of June 2002 and May 2008 who were then suitable for curative surgery, either with or without neo-adjuvant chemotherapy, were included in this study. Metabolic tumour length was assessed using both visual analysis and a maximum standardised uptake value (SUV(max)) cutoff of 2.5. RESULTS: Thirty-nine patients proceeded directly to curative surgical resection, whereas 48 patients received neo-adjuvant chemotherapy, followed by curative surgery. The 95% limits of agreement in the surgical arm were more accurate when the metabolic tumour length was visually assessed with a mean difference of -0.05 cm (SD 2.16 cm) compared to a mean difference of +2.42 cm (SD 3.46 cm) when assessed with an SUV(max) cutoff of 2.5. In the neo-adjuvant group, the 95% limits of agreement were once again more accurate when assessed visually with a mean difference of -0.6 cm (SD 1.84 cm) compared to a mean difference of +1.58 cm (SD 3.1 cm) when assessed with an SUV(max) cutoff of 2.5. CONCLUSION: This study confirms the high accuracy of PET/CT in measuring gross target volume (GTV) length. A visual method for GTV length measurement was demonstrated to be superior and more accurate than when using an SUV(max) cutoff of 2.5. This has the potential of reducing the planning target volume with dose escalation to the tumour with a corresponding reduction in normal tissue complication probability.


Assuntos
Neoplasias Esofágicas/diagnóstico , Neoplasias Esofágicas/metabolismo , Fluordesoxiglucose F18 , Tomografia por Emissão de Pósitrons , Período Pré-Operatório , Tomografia Computadorizada por Raios X , Adulto , Idoso , Neoplasias Esofágicas/patologia , Neoplasias Esofágicas/cirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Terapia Neoadjuvante , Estudos Retrospectivos , Carga Tumoral
19.
Mol Pharm ; 8(5): 1831-47, 2011 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-21815622

RESUMO

The structure, biophysical properties and biological behavior of lipopolyplex ternary gene delivery vectors incorporating novel C14 glycerol based lipids of varying alkyl chain geometry (containing cis, trans or alkyne double bonds) have been studied in the presence and absence of a bifunctional targeting peptide designed to both condense DNA and confer integrin-specific targeting. In vitro transfection studies in breast cancer MDA-MB-231 cells revealed that ternary formulations of lipid:peptide:DNA (LPD) complexes prepared using the aforementioned lipids possessed highly synergistic transfection activity up to 2500-fold higher than their respective lipid:DNA (LD) or peptide:DNA (PD) counterparts. Furthermore, the small structural differences in the lipid alkyl chain geometries also resulted in pronounced differences in transfection within each type of formulation, whereby the trans lipids showed best activity when formulated as LD complexes, whereas the cis lipids were superior in LPD formulations. Confocal fluorescence internalization studies using labeled components of the formulations showed both the lipid and the DNA of LD complexes to be trapped in endocytic compartments, whereas in the case of LPD complexes, the DNA was clearly released from the endosomal compartments and, together with the peptide, internalized within the cell nucleus. Physicochemical characterization of the formulations carried out by light and neutron scattering, zeta potential measurement, and negative staining electron microscopy detected major structural differences between LD and LPD complexes. Gel electrophoresis assays additionally showed differences between the individual lipids tested in each type of formulation. In conclusion, the superior transfection of the trans lipids in the LD complexes was thought to be attributed to superior DNA binding caused by a more closely matched charge distribution of the more rigid, trans lipids with the DNA. In the case of the LPD complexes, the DNA was thought to be predominantly condensed by the cationic portion of the peptide forming a central core surrounded by a lipid bilayer from which the targeting sequence partially protrudes. The more fluid, cis lipids were thought to confer better activity in this formulation due to allowing more of the targeting peptide sequence to protrude.


Assuntos
DNA/química , Técnicas de Transferência de Genes , Integrina alfa5beta1/metabolismo , Lipídeos/química , Proteínas de Neoplasias/metabolismo , Peptídeos/química , Plasmídeos/química , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Núcleo Celular/patologia , Fenômenos Químicos , DNA/metabolismo , Endossomos/metabolismo , Endossomos/patologia , Feminino , Corantes Fluorescentes/química , Éteres de Glicerila/química , Humanos , Ligantes , Metabolismo dos Lipídeos , Fluidez de Membrana , Conformação Molecular , Tamanho da Partícula , Peptídeos/metabolismo , Estereoisomerismo
20.
Bio Protoc ; 11(19): e4173, 2021 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-34722820

RESUMO

A failure to fully understand the complex in vivo behavior of systemically administered nanomedicines has stymied clinical translation. To bridge this knowledge gap, new in vivo tools are needed to rapidly and accurately assess the nearly infinite array of possible nanoparticle designs. Zebrafish embryos are small, transparent, and easily manipulated animals that allow for whole organism visualization of fluorescently labeled nanoparticles in real time and at cellular resolution using standard microscope setups. Furthermore, key nano-bio interactions present in higher vertebrates are fully conserved in zebrafish embryos, making these animal models a highly predictive and instructive addition to the nanomedicine design pipeline. Here, we present a step-by-step protocol to intravenously administer, image, and analyze nanoparticle behavior in zebrafish embryos and highlight key nano-bio interactions within the embryonic zebrafish corresponding to those commonly found within the mammalian liver. In addition, we outline practical steps required to achieve light-triggered activation of nanoparticles within the transparent embryo. Graphic abstract: Zebrafish embryos to study nanoparticle behavior in vivo. Formulation, intravenous administration, imaging, and analysis of nanoparticles.

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