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1.
Front Immunol ; 12: 636966, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34557180

RESUMO

Since 2003, the world has been confronted with three new betacoronaviruses that cause human respiratory infections: SARS-CoV, which causes severe acute respiratory syndrome (SARS), MERS-CoV, which causes Middle East respiratory syndrome (MERS), and SARS-CoV-2, which causes Coronavirus Disease 2019 (COVID-19). The mechanisms of coronavirus transmission and dissemination in the human body determine the diagnostic and therapeutic strategies. An important problem is the possibility that viral particles overcome tissue barriers such as the intestine, respiratory tract, blood-brain barrier, and placenta. In this work, we will 1) consider the issue of endocytosis and the possibility of transcytosis and paracellular trafficking of coronaviruses across tissue barriers with an emphasis on the intestinal epithelium; 2) discuss the possibility of antibody-mediated transcytosis of opsonized viruses due to complexes of immunoglobulins with their receptors; 3) assess the possibility of the virus transfer into extracellular vesicles during intracellular transport; and 4) describe the clinical significance of these processes. Models of the intestinal epithelium and other barrier tissues for in vitro transcytosis studies will also be briefly characterized.


Assuntos
Endocitose , Mucosa Intestinal/virologia , SARS-CoV-2/metabolismo , Anticorpos Antivirais/metabolismo , Antivirais/farmacologia , Antivirais/uso terapêutico , COVID-19/tratamento farmacológico , COVID-19/transmissão , COVID-19/virologia , Ensaios Clínicos como Assunto , Endocitose/efeitos dos fármacos , Humanos , Mucosa Intestinal/metabolismo , Modelos Biológicos , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/imunologia , Junções Íntimas/metabolismo , Junções Íntimas/virologia , Transcitose/efeitos dos fármacos , Ligação Viral
2.
Int J Mol Sci ; 22(16)2021 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-34445629

RESUMO

General cancer-targeted ligands that can deliver drugs to cells have been given considerable attention. In this paper, a high-affinity DNA aptamer (HG1) generally binding to human tumor cells was evolved by cell-SELEX, and was further optimized to have 35 deoxynucleotides (HG1-9). Aptamer HG1-9 could be taken up by live cells, and its target protein on a cell was identified to be human transferrin receptor (TfR). As a man-made ligand of TfR, aptamer HG1-9 was demonstrated to bind at the same site of human TfR as transferrin with comparable binding affinity, and was proved to cross the epithelium barrier through transferrin receptor-mediated transcytosis. These results suggest that aptamer HG1-9 holds potential as a promising ligand to develop general cancer-targeted diagnostics and therapeutics.


Assuntos
Aptâmeros de Nucleotídeos/metabolismo , Neoplasias/metabolismo , Receptores da Transferrina/metabolismo , Técnica de Seleção de Aptâmeros/métodos , Aptâmeros de Nucleotídeos/química , Humanos , Ligantes , Neoplasias/patologia , Transcitose , Células Tumorais Cultivadas
3.
Biomolecules ; 11(8)2021 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-34439797

RESUMO

Single-domain antibodies derive from the heavy-chain-only antibodies of Camelidae (camel, dromedary, llama, alpaca, vicuñas, and guananos; i.e., nanobodies) and cartilaginous fishes (i.e., VNARs). Their small size, antigen specificity, plasticity, and potential to recognize unique conformational epitopes represent a diagnostic and therapeutic opportunity for many central nervous system (CNS) pathologies. However, the blood-brain barrier (BBB) poses a challenge for their delivery into the brain parenchyma. Nevertheless, numerous neurological diseases and brain pathologies, including cancer, result in BBB leakiness favoring single-domain antibodies uptake into the CNS. Some single-domain antibodies have been reported to naturally cross the BBB. In addition, different strategies and methods to deliver both nanobodies and VNARs into the brain parenchyma can be exploited when the BBB is intact. These include device-based and physicochemical disruption of the BBB, receptor and adsorptive-mediated transcytosis, somatic gene transfer, and the use of carriers/shuttles such as cell-penetrating peptides, liposomes, extracellular vesicles, and nanoparticles. Approaches based on single-domain antibodies are reaching the clinic for other diseases. Several tailoring methods can be followed to favor the transport of nanobodies and VNARs to the CNS, avoiding the limitations imposed by the BBB to fulfill their therapeutic, diagnostic, and theragnostic promises for the benefit of patients suffering from CNS pathologies.


Assuntos
Barreira Hematoencefálica/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Portadores de Fármacos/metabolismo , Doenças Neurodegenerativas/metabolismo , Anticorpos de Domínio Único/uso terapêutico , Transcitose , Animais , Barreira Hematoencefálica/imunologia , Barreira Hematoencefálica/metabolismo , Encéfalo/irrigação sanguínea , Encéfalo/imunologia , Encéfalo/patologia , Camelidae , Peptídeos Penetradores de Células/farmacocinética , Portadores de Fármacos/química , Vesículas Extracelulares/química , Vesículas Extracelulares/metabolismo , Humanos , Lipossomos/farmacocinética , Modelos Moleculares , Nanopartículas/administração & dosagem , Doenças Neurodegenerativas/tratamento farmacológico , Doenças Neurodegenerativas/imunologia , Doenças Neurodegenerativas/patologia , Permeabilidade , Conformação Proteica , Anticorpos de Domínio Único/metabolismo
4.
ACS Appl Mater Interfaces ; 13(33): 39018-39029, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34397215

RESUMO

Targeting nanoparticles as drug delivery platforms is crucial to facilitate their cellular entry. Docking of nanoparticles by targeting ligands on cell membranes is the first step for the initiation of cellular uptake. As a model system, we studied brain microvascular endothelial cells, which form the anatomical basis of the blood-brain barrier, and the tripeptide glutathione, one of the most effective targeting ligands of nanoparticles to cross the blood-brain barrier. To investigate this initial docking step between glutathione and the membrane of living brain endothelial cells, we applied our recently developed innovative optical method. We present a microtool, with a task-specific geometry used as a probe, actuated by multifocus optical tweezers to characterize the adhesion probability and strength of glutathione-coated surfaces to the cell membrane of endothelial cells. The binding probability of the glutathione-coated surface and the adhesion force between the microtool and cell membrane was measured in a novel arrangement: cells were cultured on a vertical polymer wall and the mechanical forces were generated laterally and at the same time, perpendicularly to the plasma membrane. The adhesion force values were also determined with more conventional atomic force microscopy (AFM) measurements using functionalized colloidal probes. The optical trapping-based method was found to be suitable to measure very low adhesion forces (≤ 20 pN) without a high level of noise, which is characteristic for AFM measurements in this range. The holographic optical tweezers-directed functionalized microtools may help characterize the adhesion step of nanoparticles initiating transcytosis and select ligands to target nanoparticles.


Assuntos
Membrana Celular/metabolismo , Células Endoteliais/metabolismo , Glutationa/metabolismo , Nanopartículas/metabolismo , Pinças Ópticas , Fenômenos Biofísicos , Barreira Hematoencefálica/metabolismo , Encéfalo , Adesão Celular , Membrana Celular/ultraestrutura , Células Endoteliais/citologia , Galactosamina/química , Humanos , Ligantes , Microscopia de Força Atômica , Nanopartículas/química , Polietilenoglicóis/química , Polímeros/metabolismo , Propriedades de Superfície , Transcitose
5.
Int J Mol Sci ; 22(12)2021 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-34204226

RESUMO

FcRn plays a major role in regulating immune homeostasis, but it is also able to transport biologics across cellular barriers. The question of whether FcRn could be an efficient transporter of biologics across the nasal epithelial barrier is of particular interest, as it would allow a less invasive strategy for the administration of biologics in comparison to subcutaneous, intramuscular or intravenous administrations, which are often used in clinical practice. A focused systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. It was registered on the international prospective register of systematic reviews PROSPERO, which helped in identifying articles that met the inclusion criteria. Clinical and preclinical studies involving FcRn and the nasal delivery of biologics were screened, and the risk of bias was assessed across studies using the Oral Health Assessment Tool (OHAT). Among the 12 studies finally included in this systematic review (out of the 758 studies screened), 11 demonstrated efficient transcytosis of biologics through the nasal epithelium. Only three studies evaluated the potential toxicity of biologics' intranasal delivery, and they all showed that it was safe. This systematic review confirmed that FcRn is expressed in the nasal airway and the olfactory epithelium, and that FcRn may play a role in IgG and/or IgG-derived molecule-transcytosis across the airway epithelium. However, additional research is needed to better characterize the pharmacokinetic and pharmacodynamic properties of biologics after their intranasal delivery.


Assuntos
Produtos Biológicos/administração & dosagem , Antígenos de Histocompatibilidade Classe I/metabolismo , Mucosa Nasal/efeitos dos fármacos , Mucosa Nasal/metabolismo , Receptores Fc/metabolismo , Animais , Produtos Biológicos/metabolismo , Transporte Biológico , Biomarcadores , Sistemas de Liberação de Medicamentos , Expressão Gênica , Antígenos de Histocompatibilidade Classe I/química , Antígenos de Histocompatibilidade Classe I/genética , Humanos , Ligação Proteica , Receptores Fc/química , Receptores Fc/genética , Transcitose
6.
Nat Commun ; 12(1): 4121, 2021 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-34226541

RESUMO

Effective treatments of neurodegenerative diseases require drugs to be actively transported across the blood-brain barrier (BBB). However, nanoparticle drug carriers explored for this purpose show negligible brain uptake, and the lack of basic understanding of nanoparticle-BBB interactions underlies many translational failures. Here, using two-photon microscopy in mice, we characterize the receptor-mediated transcytosis of nanoparticles at all steps of delivery to the brain in vivo. We show that transferrin receptor-targeted liposome nanoparticles are sequestered by the endothelium at capillaries and venules, but not at arterioles. The nanoparticles move unobstructed within endothelium, but transcytosis-mediated brain entry occurs mainly at post-capillary venules, and is negligible in capillaries. The vascular location of nanoparticle brain entry corresponds to the presence of perivascular space, which facilitates nanoparticle movement after transcytosis. Thus, post-capillary venules are the point-of-least resistance at the BBB, and compared to capillaries, provide a more feasible route for nanoparticle drug carriers into the brain.


Assuntos
Encéfalo/metabolismo , Capilares/metabolismo , Portadores de Fármacos , Nanopartículas/uso terapêutico , Transcitose/fisiologia , Vênulas/metabolismo , Animais , Arteríolas , Transporte Biológico , Barreira Hematoencefálica , Capilares/patologia , Endotélio/diagnóstico por imagem , Endotélio/patologia , Cinética , Lipossomos/metabolismo , Camundongos , Receptores da Transferrina/metabolismo , Vênulas/patologia
7.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 52(4): 570-576, 2021 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-34323033

RESUMO

Objective: To construct solid lipid nanoparticle (SNPs) drug delivery system loaded with peptide and protein drugs by using mixedsolvents, to study the transcytosis mechanisms of SNPs across intestinal epithelial cells, and to improve the endocytosis and transcytosis efficiency of peptide and protein drugs. Methods: The formulation of insulin-loaded water-in-oil-in-water solid lipid nanoparticles (INS-SNPs) was prepared by using a methanol-chloroform mixed solvent. The formulation was optimized with the single factor screening method. The optimized INS-SNPs were then characterized in terms of their morphology, stability and drug release properties. The cytotoxicity, cellular uptake and endocytosis mechanisms of INS-SNPs were then assessed on Caco-2 cells. The transcytosis efficiency of INS-SNPs was finally evaluated by using cellular monolayer in Transwell ® insert. Results: The size, zeta potentials and drug loading efficiency of the optimized INS-SNPs were observed to be (145.4±0.5) nm, (-12.9±0.2) mV and (7.93±0.02)%, respectively. INS-SNPs were then shown to maintain desirable colloidal stability and sustained release of insulin in the simulated intestinal fluid. It was revealed that the cellular uptake of INS-SNPs reached its maximum after cellular incubation for 2 hours and was 1.53-fold higher than that of free insulin. Investigation of the endocytic mechanism revealed that INS-SNPs enter intestinal epithelial cells mainly through the clathrin-mediated and caveolae-mediated endocytosis pathways. Further investigation revealed that the amount of INS-SNPs permeating the cell monolayers was 1.54-fold higher than that of free insulin, which was comparable to the increase in their cellular uptake efficiency, indicating that INS-SNPs displayed enhanced absorption across the intestinal epithelium. Conclusion: The INS-SNPs prepared with mixed solvents in this study could significantly enhance the transcytosis efficiency of peptide and protein drugs, displaying great potentials in the application of oral drug delivery. This study may provide information and reference for the designing of efficient oral nano-drug delivery system in the future.


Assuntos
Insulina , Nanopartículas , Administração Oral , Células CACO-2 , Portadores de Fármacos , Humanos , Lipídeos , Transcitose
8.
Nat Biomed Eng ; 5(8): 830-846, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34127820

RESUMO

The neurovascular unit, which consists of vascular cells surrounded by astrocytic end-feet and neurons, controls cerebral blood flow and the permeability of the blood-brain barrier (BBB) to maintain homeostasis in the neuronal milieu. Studying how some pathogens and drugs can penetrate the human BBB and disrupt neuronal homeostasis requires in vitro microphysiological models of the neurovascular unit. Here we show that the neurotropism of Cryptococcus neoformans-the most common pathogen causing fungal meningitis-and its ability to penetrate the BBB can be modelled by the co-culture of human neural stem cells, brain microvascular endothelial cells and brain vascular pericytes in a human-neurovascular-unit-on-a-chip maintained by a stepwise gravity-driven unidirectional flow and recapitulating the structural and functional features of the BBB. We found that the pathogen forms clusters of cells that penetrate the BBB without altering tight junctions, suggesting a transcytosis-mediated mechanism. The neurovascular-unit-on-a-chip may facilitate the study of the mechanisms of brain infection by pathogens, and the development of drugs for a range of brain diseases.


Assuntos
Barreira Hematoencefálica/metabolismo , Cryptococcus neoformans/fisiologia , Dispositivos Lab-On-A-Chip , Modelos Biológicos , Barreira Hematoencefálica/química , Barreira Hematoencefálica/microbiologia , Técnicas de Cocultura , Células Endoteliais/citologia , Células Endoteliais/metabolismo , Matriz Extracelular/química , Humanos , Hidrogéis/química , Meningite/microbiologia , Meningite/patologia , Microvasos/citologia , Células-Tronco Neurais/citologia , Células-Tronco Neurais/metabolismo , Pericitos/citologia , Pericitos/metabolismo , Transcitose
9.
Biomaterials ; 274: 120888, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34029915

RESUMO

The modification of targeting ligands on nanoparticles (NPs) is anticipated to enhance the delivery of therapeutics to diseased tissues. However, once exposed to the blood stream, NPs can immediately adsorb proteins to form the "protein corona," which may greatly hinder the targeting ligand from binding to its receptor. For brain-targeting delivery, nanotherapeutics must traverse the blood-brain barrier (BBB) to enter the brain parenchyma and then target the diseased cells. However, it remains elusive whether, apart from receptor recognition, the protein corona can affect other processes involved in BBB transcytosis, such as endocytosis, intracellular trafficking, and exocytosis. Furthermore, the targeting ability of NPs toward diseased cells after transcytosis remains unclear. Herein, transferrin (Tf), a brain-targeting ligand, was coupled to NPs to evaluate BBB transcytosis and brain tumor targeting ability. Different impacts of the in vitro and in vivo protein corona on receptor targeting, lysosomal escape, and BBB transcytosis were found. The in vitro protein corona abolished the Tf-mediated effects of the abovementioned processes, whereas the in vivo protein corona attenuated these effects. After crossing the BBB, Tf retained its targeting specificity towards brain tumor cells. Together, these results revealed that several bound apolipoproteins, especially apolipoprotein A-I, may help NPs traverse the BBB, thereby providing novel insights into the development of brain-targeted delivery.


Assuntos
Neoplasias Encefálicas , Nanopartículas , Coroa de Proteína , Barreira Hematoencefálica/metabolismo , Encéfalo/metabolismo , Humanos , Transcitose , Transferrina
10.
Int J Mol Sci ; 22(7)2021 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-33805888

RESUMO

Oral administration of medications is highly preferred in healthcare owing to its simplicity and convenience; however, problems of drug membrane permeability can arise with any administration method in drug discovery and development. In particular, commonly used monoclonal antibody (mAb) drugs are directly injected through intravenous or subcutaneous routes across physical barriers such as the cell membrane, including the epithelium and endothelium. However, intravenous administration has disadvantages such as pain, discomfort, and stress. Oral administration is an ideal route for mAbs. Nonetheless, proteolysis and denaturation, in addition to membrane impermeability, pose serious challenges in delivering peroral mAbs to the systemic circulation, biologically, through enzymatic and acidic blocks and, physically, through the small intestinal epithelium barrier. A number of clinical trials have been performed using oral mAbs for the local treatment of gastrointestinal diseases, some of which have adopted capsules or tablets as formulations. Surprisingly, no oral mAbs have been approved clinically. An enteric nanodelivery system can protect cargos from proteolysis and denaturation. Moreover, mAb cargos released in the small intestine may be delivered to the systemic circulation across the intestinal epithelium through receptor-mediated transcytosis. Oral Abs in milk are transported by neonatal Fc receptors to the systemic circulation in neonates. Thus, well-designed approaches can establish oral mAb delivery. In this review, I will introduce the implementation and possibility of delivering orally administered mAbs with or without nanoparticles not only to the local gastrointestinal tract but also to the systemic circulation.


Assuntos
Anticorpos Monoclonais/administração & dosagem , Sistemas de Liberação de Medicamentos , Nanopartículas/química , Administração Oral , Albuminas/química , Animais , Ensaios Clínicos como Assunto , Endocitose , Humanos , Concentração de Íons de Hidrogênio , Imunoterapia , Mucosa Intestinal/metabolismo , Mucosa Intestinal/virologia , Intestino Delgado/metabolismo , Intestino Delgado/virologia , Camundongos , Norovirus , Peptídeos/química , Ratos , Transcitose
11.
PLoS One ; 16(4): e0249686, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33798235

RESUMO

The blood-brain barrier (BBB) is one of the main obstacles for therapies targeting brain diseases. Most macromolecules fail to pass the tight BBB, formed by brain endothelial cells interlinked by tight junctions. A wide range of small, lipid-soluble molecules can enter the brain parenchyma via diffusion, whereas macromolecules have to transcytose via vesicular transport. Vesicular transport can thus be utilized as a strategy to deliver brain therapies. By conjugating BBB targeting antibodies and peptides to therapeutic molecules or nanoparticles, it is possible to increase uptake into the brain. Previously, the synthetic peptide GYR and a peptide derived from melanotransferrin (MTfp) have been suggested as candidates for mediating transcytosis in brain endothelial cells (BECs). Here we study uptake, intracellular trafficking, and translocation of these two peptides in BECs. The peptides were synthesized, and binding studies to purified endocytic receptors were performed using surface plasmon resonance. Furthermore, the peptides were conjugated to a fluorophore allowing for live-cell imaging studies of their uptake into murine brain endothelial cells. Both peptides bound to low-density lipoprotein receptor-related protein 1 (LRP-1) and the human transferrin receptor, while lower affinity was observed against the murine transferrin receptor. The MTfp showed a higher binding affinity to all receptors when compared to the GYR peptide. The peptides were internalized by the bEnd.3 mouse endothelial cells within 30 min of incubation and frequently co-localized with endo-lysosomal vesicles. Moreover, our in vitro Transwell translocation experiments confirmed that GYR was able to cross the murine barrier and indicated the successful translocation of MTfp. Thus, despite binding to endocytic receptors with different affinities, both peptides are able to transcytose across the murine BECs.


Assuntos
Barreira Hematoencefálica/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Sistemas de Liberação de Medicamentos/métodos , Células Endoteliais/efeitos dos fármacos , Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa Densidade/antagonistas & inibidores , Peptídeos/farmacologia , Receptores da Transferrina/antagonistas & inibidores , Animais , Barreira Hematoencefálica/metabolismo , Encéfalo/metabolismo , Células Cultivadas , Células Endoteliais/metabolismo , Corantes Fluorescentes/química , Corantes Fluorescentes/farmacologia , Humanos , Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa Densidade/metabolismo , Glicoproteínas de Membrana/metabolismo , Camundongos , Receptores da Transferrina/metabolismo , Transcitose
12.
Int J Biol Macromol ; 182: 1003-1014, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-33892025

RESUMO

Pumpkin polysaccharides with various bioactivities are mainly taken orally, thus detailed knowledge of the intestinal transport of which are essential for understanding its bioactivities. The Caco-2 cells monolayer model (mimic intestinal epithelium) was successfully constructed and Cucurbia moschata polysaccharides (PPc-F) were successfully conjugated with fluorescein isothiocyanate (FITC) to evaluate the transcellular transport mechanism and subcellular localization of PPc. The transport process of PPc-F was energy-dependent, and a moderately-absorbed biological macromolecule according to the apparent permeability coefficients (Papp) value. The endocytosis process of PPc-F in Caco-2 cells included the clathrin- and caveolae (or lipid draft)-medicated routes. And the translocation process was related to endoplasmic reticulum (ER), golgi apparatus (GA), tubulin and the acidification of endosomes. As for the intracellular location of PPc-F, it was mainly accumulated in ER. The study provided an understanding of the transmembrane transport of PPc-F, and could help studying the mechanisms of its effects.


Assuntos
Cucurbita/química , Endocitose , Polissacarídeos/química , Células CACO-2 , Cavéolas/metabolismo , Retículo Endoplasmático/metabolismo , Fluoresceína/química , Humanos , Microdomínios da Membrana/metabolismo , Polissacarídeos/metabolismo , Transcitose
13.
Adv Healthc Mater ; 10(9): e2001997, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33738958

RESUMO

Microvessels of the blood-brain barrier (BBB) exclusively express the major facilitator superfamily domain-containing protein 2a (Mfsd2a), which is the key transporter for docosahexaenoic acid uptake into the brain. Mfsd2a suppresses caveolae-mediated transcytosis to regulate BBB transcellular permeability via controlling lipid composition of BBB endothelial cells. It is speculated that Mfsd2a can restrain BBB crossing efficiency and brain accumulation efficiency of brain-targeting drug delivery systems, which penetrate the BBB often through the receptor-mediated transcytosis pathway. Transcytosis across the BBB is a crucial bottleneck for targeted chemotherapy of brain metastases. To overcome this issue, a pair of priming nanoparticles (NPs) and following drug-loaded NPs are designed. Tunicamycin-(TM)-loaded transcytosis-targeting-peptide-(TTP)-decorated NPs (TM@TTP) are used to boost BBB transcytosis via inhibiting Mfsd2a. Doxorubicin (DOX)-loaded TTP and CD44-specific hyaluronic acid (HA)-comodified NPs (DOX@TTP-HA) are designed as following drug-loaded NPs. The brain accumulation efficacy of following DOX@TTP-HA with priming is 4.30-fold higher than that without priming through the enhanced transcytosis pathway rather than the tight junction opening. Effective BBB crossing and brain accumulation, selective tumor uptake, excellent antitumor efficacy, and low hepatotoxicity are achieved by TM@TTP and DOX@TTP-HA, suggesting this tactic as a significant therapeutic strategy against breast cancer brain metastases.


Assuntos
Neoplasias Encefálicas , Nanopartículas , Simportadores , Barreira Hematoencefálica , Encéfalo , Neoplasias Encefálicas/tratamento farmacológico , Células Endoteliais , Humanos , Transcitose
14.
Int J Mol Sci ; 22(5)2021 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-33668983

RESUMO

Transcytosis of polymeric IgA and IgM from the basolateral surface to the apical side of the epithelium and subsequent secretion into mucosal fluids are mediated by the polymeric immunoglobulin receptor (pIgR). Secreted IgA and IgM have vital roles in mucosal immunity in response to pathogenic infections. Binding and recognition of polymeric IgA and IgM by pIgR require the joining chain (J chain), a small protein essential in the formation and stabilization of polymeric Ig structures. Recent studies have identified marginal zone B and B1 cell-specific protein (MZB1) as a novel regulator of polymeric IgA and IgM formation. MZB1 might facilitate IgA and IgM transcytosis by promoting the binding of J chain to Ig. In this review, we discuss the roles of pIgR in transcytosis of IgA and IgM, the roles of J chain in the formation of polymeric IgA and IgM and recognition by pIgR, and focus particularly on recent progress in understanding the roles of MZB1, a molecular chaperone protein.


Assuntos
Imunoglobulina A/metabolismo , Imunoglobulina M/metabolismo , Receptores de Imunoglobulina Polimérica/metabolismo , Transcitose , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Humanos , Polimerização
15.
Methods Mol Biol ; 2224: 123-132, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33606211

RESUMO

Proteinuria is a widely used marker of renal disease and is strongly associated with renal and cardiovascular outcomes. The molecular mechanisms underlying filtration of serum proteins through the glomerular filtration barrier (GFB) remain to be determined. Since the GFB is a complex structure, studies of albumin or IgG trafficking in cultured cells in vitro may not fully recapitulate these processes in vivo. In other epithelial cells including renal proximal tubular cells, the neonatal Fc receptor (FcRn) is required to divert albumin and IgG from the degradative pathway which allows these proteins to be recycled or transcytosed. To examine the role of podocyte FcRn in albumin and IgG trafficking in vivo, we detail the creation of a podocyte-specific FcRn knockout mouse and describe methods for examining intraglomerular detection of albumin and IgG in these mice.


Assuntos
Antígenos de Histocompatibilidade Classe I/metabolismo , Podócitos/metabolismo , Receptores Fc/metabolismo , Albuminas/metabolismo , Animais , Células Epiteliais/metabolismo , Feminino , Imunoglobulina G/metabolismo , Túbulos Renais Proximais/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Transporte Proteico/fisiologia , Proteinúria/metabolismo , Transcitose/fisiologia
16.
Circ Res ; 128(3): 433-450, 2021 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-33539224

RESUMO

Lipid uptake and metabolism are central to the function of organs such as heart, skeletal muscle, and adipose tissue. Although most heart energy derives from fatty acids (FAs), excess lipid accumulation can cause cardiomyopathy. Similarly, high delivery of cholesterol can initiate coronary artery atherosclerosis. Hearts and arteries-unlike liver and adrenals-have nonfenestrated capillaries and lipid accumulation in both health and disease requires lipid movement from the circulation across the endothelial barrier. This review summarizes recent in vitro and in vivo findings on the importance of endothelial cell receptors and uptake pathways in regulating FAs and cholesterol uptake in normal physiology and cardiovascular disease. We highlight clinical and experimental data on the roles of ECs in lipid supply to tissues, heart, and arterial wall in particular, and how this affects organ metabolism and function. Models of FA uptake into ECs suggest that receptor-mediated uptake predominates at low FA concentrations, such as during fasting, whereas FA uptake during lipolysis of chylomicrons may involve paracellular movement. Similarly, in the setting of an intact arterial endothelial layer, recent and historic data support a role for receptor-mediated processes in the movement of lipoproteins into the subarterial space. We conclude with thoughts on the need to better understand endothelial lipid transfer for fuller comprehension of the pathophysiology of hyperlipidemia, and lipotoxic diseases such as some forms of cardiomyopathy and atherosclerosis.


Assuntos
Colesterol/metabolismo , Células Endoteliais/metabolismo , Proteínas de Transporte de Ácido Graxo/metabolismo , Ácidos Graxos/metabolismo , Transtornos do Metabolismo dos Lipídeos/metabolismo , Transcitose , Animais , Antígenos CD36/metabolismo , Quilomícrons/metabolismo , Humanos , Transtornos do Metabolismo dos Lipídeos/patologia , Lipólise , Tamanho da Partícula
18.
Commun Biol ; 4(1): 173, 2021 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-33564097

RESUMO

Glycoproteins and glycolipids at the plasma membrane contribute to a range of functions from growth factor signaling to cell adhesion and migration. Glycoconjugates undergo endocytic trafficking. According to the glycolipid-lectin (GL-Lect) hypothesis, the construction of tubular endocytic pits is driven in a glycosphingolipid-dependent manner by sugar-binding proteins of the galectin family. Here, we provide evidence for a function of the GL-Lect mechanism in transcytosis across enterocytes in the mouse intestine. We show that galectin-3 (Gal3) and its newly identified binding partner lactotransferrin are transported in a glycosphingolipid-dependent manner from the apical to the basolateral membrane. Transcytosis of lactotransferrin is perturbed in Gal3 knockout mice and can be rescued by exogenous Gal3. Inside enterocytes, Gal3 is localized to hallmark structures of the GL-Lect mechanism, termed clathrin-independent carriers. These data pioneer the existence of GL-Lect endocytosis in vivo and strongly suggest that polarized trafficking across the intestinal barrier relies on this mechanism.


Assuntos
Enterócitos/metabolismo , Galectina 3/metabolismo , Glicoesfingolipídeos/metabolismo , Jejuno/metabolismo , Lactoferrina/metabolismo , Transcitose , Animais , Proteínas Sanguíneas/metabolismo , Enterócitos/ultraestrutura , Galectina 3/deficiência , Galectina 3/genética , Galectinas/metabolismo , Jejuno/ultraestrutura , Camundongos Endogâmicos C57BL , Camundongos Knockout
19.
Nat Commun ; 12(1): 261, 2021 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-33431850

RESUMO

Intestinal microfold cells are the primary pathway for translocation of secretory IgA (SIgA)-pathogen complexes to gut-associated lymphoid tissue. Uptake of SIgA/commensals complexes is important for priming adaptive immunity in the mucosa. This study aims to explore the effect of SIgA retrograde transport of immune complexes in Crohn's disease (CD). Here we report a significant increase of SIgA transport in CD patients with NOD2-mutation compared to CD patients without NOD2 mutation and/or healthy individuals. NOD2 has an effect in the IgA transport through human and mouse M cells by downregulating Dectin-1 and Siglec-5 expression, two receptors involved in retrograde transport. These findings define a mechanism of NOD2-mediated regulation of mucosal responses to intestinal microbiota, which is involved in CD intestinal inflammation and dysbiosis.


Assuntos
Doença de Crohn/metabolismo , Imunoglobulina A Secretora/metabolismo , Proteína Adaptadora de Sinalização NOD2/metabolismo , Animais , Colite/microbiologia , Colite/patologia , Doença de Crohn/patologia , Humanos , Lectinas Tipo C/metabolismo , Camundongos Knockout , Modelos Biológicos , Mutação/genética , Proteína Adaptadora de Sinalização NOD2/deficiência , Proteína Adaptadora de Sinalização NOD2/genética , Nódulos Linfáticos Agregados/metabolismo , Transporte Proteico , Salmonella/fisiologia , Lectinas Semelhantes a Imunoglobulina de Ligação ao Ácido Siálico/metabolismo , Transcitose
20.
Int J Pharm ; 593: 120146, 2021 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-33279714

RESUMO

Lecithin coated cholesteryl oleate (ChOl) based nanoparticles (NPs) imitating natural lipoproteins represent a new and promising drug carrier strategy to cross the blood-brain barrier (BBB). In such systems lecithin serves as stabilizing as well as functionalizing agent and enables the adsorptive binding of apolipoprotein E3 (ApoE) as potential drug targeting ligand. The present work is focused on the effect of size reduction on the lecithin coating and ApoE binding. Furthermore, the transferability of this lecithin coating strategy to other NP cores, namely polylactic-co-glycolic acid (PLGA) and polylactic acid (PLA), is investigated in order to provide a universal strategy for a wide range of cores to overcome the BBB. The ChOl NPs' size was successfully reduced from 100 nm to 70 nm. Varying the core size of ChOl NPs illustrated, that the at least needed lecithin amount for sufficient stabilization could be calculated surface area dependently. However, the size reduction led to reduced dye loading per NP and increased ApoE need per NP mass. These effects turned out as huge disadvantages of smaller NPs by weakening the observed ApoE mediated effects. Nevertheless, the extended understanding of the lecithin coating could be used to transfer the concept to other core materials. PLGA and PLA NPs were investigated as alternative core materials for lecithin coating. PLGA was found to be unsuitable, whereas in the case of PLA sufficient stabilization and 100% adsorptive binding efficiency to ApoE could be achieved. The ApoE mediated effects of transcytosis at an in vitro BBB model by bypassing lysosomes were reproduced in even stronger quantities than with a ChOl core, proving lecithin coating as transferable strategy to disguise various NPs with a certain lipophilicity as lipoproteins.


Assuntos
Portadores de Fármacos , Nanopartículas , Barreira Hematoencefálica , Lecitinas , Tamanho da Partícula , Transcitose
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