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1.
Nat Commun ; 12(1): 3451, 2021 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-34103486

RESUMO

Several cell-surface receptors for neurotoxic forms of amyloid-ß (Aß) have been described, but their molecular interactions with Aß assemblies and their relative contributions to mediating Alzheimer's disease pathology have remained uncertain. Here, we used super-resolution microscopy to directly visualize Aß-receptor interactions at the nanometer scale. We report that one documented Aß receptor, PrPC, specifically inhibits the polymerization of Aß fibrils by binding to the rapidly growing end of each fibril, thereby blocking polarized elongation at that end. PrPC binds neurotoxic oligomers and protofibrils in a similar fashion, suggesting that it may recognize a common, end-specific, structural motif on all of these assemblies. Finally, two other Aß receptors, FcγRIIb and LilrB2, affect Aß fibril growth in a manner similar to PrPC. Our results suggest that receptors may trap Aß oligomers and protofibrils on the neuronal surface by binding to a common molecular determinant on these assemblies, thereby initiating a neurotoxic signal.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Amiloide/metabolismo , Neurotoxinas/química , Multimerização Proteica , Receptores de Superfície Celular/metabolismo , Animais , Benzotiazóis/metabolismo , Calmodulina/metabolismo , Humanos , Cinética , Camundongos , Modelos Biológicos , Polimerização , Príons/metabolismo , Ligação Proteica , Receptores de IgG/metabolismo , Receptores Imunológicos/metabolismo
2.
PLoS Pathog ; 17(5): e1009576, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-34015061

RESUMO

The efficient spread of SARS-CoV-2 resulted in a unique pandemic in modern history. Despite early identification of ACE2 as the receptor for viral spike protein, much remains to be understood about the molecular events behind viral dissemination. We evaluated the contribution of C-type lectin receptors (CLRS) of antigen-presenting cells, widely present in respiratory mucosa and lung tissue. DC-SIGN, L-SIGN, Langerin and MGL bind to diverse glycans of the spike using multiple interaction areas. Using pseudovirus and cells derived from monocytes or T-lymphocytes, we demonstrate that while virus capture by the CLRs examined does not allow direct cell infection, DC/L-SIGN, among these receptors, promote virus transfer to permissive ACE2+ Vero E6 cells. A glycomimetic compound designed against DC-SIGN, enable inhibition of this process. These data have been then confirmed using authentic SARS-CoV-2 virus and human respiratory cell lines. Thus, we described a mechanism potentiating viral spreading of infection.


Assuntos
COVID-19/transmissão , Lectinas Tipo C/metabolismo , SARS-CoV-2/metabolismo , Glicoproteína da Espícula de Coronavírus/metabolismo , Animais , Antígenos CD/metabolismo , COVID-19/prevenção & controle , Moléculas de Adesão Celular/metabolismo , Linhagem Celular , Chlorocebus aethiops , Humanos , Células Jurkat , Pulmão/metabolismo , Lectinas de Ligação a Manose/metabolismo , Manosídeos/farmacologia , Ligação Proteica/efeitos dos fármacos , Receptores de Superfície Celular/metabolismo , Mucosa Respiratória/metabolismo , Células Vero
3.
Nat Commun ; 12(1): 3172, 2021 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-34039996

RESUMO

Secreted class 3 semaphorins (Sema3s) form tripartite complexes with the plexin receptor and neuropilin coreceptor, which are both transmembrane proteins that together mediate semaphorin signal for neuronal axon guidance and other processes. Despite extensive investigations, the overall architecture of and the molecular interactions in the Sema3/plexin/neuropilin complex are incompletely understood. Here we present the cryo-EM structure of a near intact extracellular region complex of Sema3A, PlexinA4 and Neuropilin 1 (Nrp1) at 3.7 Å resolution. The structure shows a large symmetric 2:2:2 assembly in which each subunit makes multiple interactions with others. The two PlexinA4 molecules in the complex do not interact directly, but their membrane proximal regions are close to each other and poised to promote the formation of the intracellular active dimer for signaling. The structure reveals a previously unknown interface between the a2b1b2 module in Nrp1 and the Sema domain of Sema3A. This interaction places the a2b1b2 module at the top of the complex, far away from the plasma membrane where the transmembrane regions of Nrp1 and PlexinA4 embed. As a result, the region following the a2b1b2 module in Nrp1 must span a large distance to allow the connection to the transmembrane region, suggesting an essential role for the long non-conserved linkers and the MAM domain in neuropilin in the semaphorin/plexin/neuropilin complex.


Assuntos
Proteínas do Tecido Nervoso/ultraestrutura , Neuropilina-1/ultraestrutura , Receptores de Superfície Celular/ultraestrutura , Semaforina-3A/ultraestrutura , Animais , Células COS , Chlorocebus aethiops , Microscopia Crioeletrônica , Células HEK293 , Humanos , Mutação , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/isolamento & purificação , Proteínas do Tecido Nervoso/metabolismo , Neuropilina-1/genética , Neuropilina-1/isolamento & purificação , Neuropilina-1/metabolismo , Ligação Proteica/genética , Domínios Proteicos/genética , Multimerização Proteica/genética , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/isolamento & purificação , Receptores de Superfície Celular/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/ultraestrutura , Semaforina-3A/genética , Semaforina-3A/isolamento & purificação , Semaforina-3A/metabolismo
4.
Nat Commun ; 12(1): 2904, 2021 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-34006855

RESUMO

Enterovirus D68 (EV-D68) is an emerging pathogen associated with respiratory diseases and/or acute flaccid myelitis. Here, two MAbs, 2H12 and 8F12, raised against EV-D68 virus-like particle (VLP), show distinct preference in binding VLP and virion and in neutralizing different EV-D68 strains. A combination of 2H12 and 8F12 exhibits balanced and potent neutralization effects and confers broader protection in mice than single MAbs when given at onset of symptoms. Cryo-EM structures of EV-D68 virion complexed with 2H12 or 8F12 show that both antibodies bind to the canyon region of the virion, creating steric hindrance for sialic acid receptor binding. Additionally, 2H12 binding can impair virion integrity and trigger premature viral uncoating. We also capture an uncoating intermediate induced by 2H12 binding, not previously described for picornaviruses. Our study elucidates the structural basis and neutralizing mechanisms of the 2H12 and 8F12 MAbs and supports further development of the 2H12/8F12 cocktail as a broad-spectrum therapeutic agent against EV-D68 infections in humans.


Assuntos
Anticorpos Monoclonais/imunologia , Enterovirus Humano D/imunologia , Infecções por Enterovirus/imunologia , Vírion/imunologia , Animais , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/metabolismo , Anticorpos Neutralizantes/administração & dosagem , Anticorpos Neutralizantes/imunologia , Anticorpos Neutralizantes/metabolismo , Linhagem Celular Tumoral , Microscopia Crioeletrônica , Enterovirus Humano D/efeitos dos fármacos , Enterovirus Humano D/fisiologia , Infecções por Enterovirus/tratamento farmacológico , Infecções por Enterovirus/virologia , Feminino , Humanos , Camundongos Endogâmicos BALB C , Ligação Proteica/efeitos dos fármacos , Receptores de Superfície Celular/imunologia , Receptores de Superfície Celular/metabolismo , Tempo para o Tratamento , Resultado do Tratamento , Vírion/efeitos dos fármacos , Vírion/metabolismo , Vírion/ultraestrutura , Desenvelopamento do Vírus/efeitos dos fármacos
5.
Int J Mol Sci ; 22(5)2021 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-33799989

RESUMO

Despite the confirmed anti-cancer effects of T-cell immune checkpoint inhibitors, in colorectal cancer (CRC) they are only effective in a small subset of patients with microsatellite-unstable tumors. Thus, therapeutics targeting other types of CRCs or tumors refractory to T-cell checkpoint inhibitors are desired. The binding of aberrantly expressed CD47 on tumor cells to signal regulatory protein-alpha (SIRPA) on macrophages allows tumor cells to evade immune destruction. Based on these observations, drugs targeting the macrophage checkpoint have been developed with the expectation of anti-cancer effects against T-cell immune checkpoint inhibitor-refractory tumors. In the present study, 269 primary CRCs were evaluated immunohistochemically for CD47, SIRPA, CD68, and CD163 expression to assess their predictive utility and the applicability of CD47-SIRPA axis-modulating drugs. Thirty-five percent of the lesions (95/269) displayed CD47 expression on the cytomembrane of CRC cells. CRCs contained various numbers of tumor-associated immune cells (TAIs) with SIRPA, CD68, or CD163 expression. The log-rank test revealed that patients with CD47-positive CRCs had significantly worse survival than CD47-negative patients. Multivariate Cox hazards regression analysis identified tubular-forming histology (hazard ratio (R) = 0.23), age < 70 years (HR = 0.48), and high SIRPA-positive TAI counts (HR = 0.55) as potential favorable factors. High tumor CD47 expression (HR = 1.75), lymph node metastasis (HR = 2.26), and peritoneal metastasis (HR = 5.80) were cited as potential independent risk factors. Based on our observations, CD47-SIRPA pathway-modulating therapies may be effective in patients with CRC.


Assuntos
Antígenos de Diferenciação/metabolismo , Antígeno CD47/metabolismo , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/patologia , Receptores Imunológicos/metabolismo , Idoso , Idoso de 80 Anos ou mais , Antígenos CD/metabolismo , Antígenos de Diferenciação Mielomonocítica/metabolismo , Biomarcadores Tumorais/metabolismo , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/cirurgia , Feminino , Humanos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Macrófagos/metabolismo , Macrófagos/patologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Receptores de Superfície Celular/metabolismo , Análise de Sobrevida
6.
Int J Mol Sci ; 22(6)2021 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-33809794

RESUMO

In recent years, a major rise in the demand for biotherapeutic drugs has centered on enhancing the quality and efficacy of cell culture and developing new cell culture techniques. Here, we report fibronectin (FN) derived, novel peptides fibronectin-based intergrin binding peptide (FNIN)2 (18-mer) and FNIN3 (20-mer) which promote cell adhesion proliferation, and the differentiation of primary cells and stem cells. FNIN2 and 3 were designed based on the in silico interaction studies between FN and its receptors (integrin α5ß1, αvß3, and αIIbß3). Analysis of the proliferation of seventeen-cell types showed that the effects of FNINs depend on their concentration and the existence of expressed integrins. Significant rhodamine-labeled FNIN2 fluorescence on the membranes of HeLa, HepG2, A498, and Du145 cells confirmed physical binding. Double coating with FNIN2 or 3 after polymerized dopamine (pDa) or polymerized tannic acid (pTA) precoating increased HBEpIC cell proliferation by 30-40 percent, suggesting FNINs potently affect primary cells. Furthermore, the proliferation of C2C12 myoblasts and human mesenchymal stem cells (MSCs) treated with FNINs was significantly increased in 2D/3D culture. FNINs also promoted MSC differentiation into osteoblasts. The results of this study offer a new approach to the production of core materials (e.g., cell culture medium components, scaffolds) for cell culture.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Fibronectinas/química , Células-Tronco Mesenquimais/citologia , Peptídeos/farmacologia , Alginatos , Animais , Adesão Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Células HeLa , Humanos , Integrinas/metabolismo , Células-Tronco Mesenquimais/efeitos dos fármacos , Camundongos , Modelos Moleculares , Osteogênese/efeitos dos fármacos , Domínios Proteicos , Ratos , Receptores de Superfície Celular/metabolismo
7.
Int J Mol Sci ; 22(6)2021 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-33802041

RESUMO

The phytohormone auxin is involved in almost every process of a plant's life, from germination to plant development. Nowadays, auxin research connects synthetic chemistry, plant biology and computational chemistry in order to develop innovative and safe compounds to be used in sustainable agricultural practice. In this framework, we developed new fluorescent compounds, ethanolammonium p-aminobenzoate (HEA-pABA) and p-nitrobenzoate (HEA-pNBA), and investigated their auxin-like behavior on two main commercial vegetables cultivated in Europe, cucumber (Cucumis sativus) and tomato (Solanumlycopersicum), in comparison to the model plant Arabidopsis (Arabidopsis thaliana). Moreover, the binding modes and affinities of two organic salts in relation to the natural auxin indole-3-acetic acid (IAA) into TIR1 auxin receptor were investigated by computational approaches (homology modeling and molecular docking). Both experimental and theoretical results highlight HEA-pABA as a fluorescent compound with auxin-like activity both in Arabidopsis and the commercial cucumber and tomato. Therefore, alkanolammonium benzoates have a great potential as promising sustainable plant growth stimulators to be efficiently used in vegetable crops.


Assuntos
Arabidopsis/metabolismo , Bioprospecção/métodos , Cucumis sativus/metabolismo , Lycopersicon esculentum/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Fluorescência , Ácidos Indolacéticos/metabolismo , Simulação de Acoplamento Molecular , Nitrobenzoatos/metabolismo , Reguladores de Crescimento de Plantas/química , Proteínas de Plantas/metabolismo , Ligação Proteica , Receptores de Superfície Celular/metabolismo
8.
Mol Pharmacol ; 99(5): 319-327, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33824185

RESUMO

Children have difficulty swallowing capsules. Yet, when presented with liquid formulations, children often reject oral medications due to their intense bitterness. Presently, effective strategies to identify methods, reagents, and tools to block bitterness remain elusive. For a specific bitter-tasting drug, identification of the responsible bitter receptors and discovery of antagonists for those receptors can provide a method to block perceived bitterness. We have identified a compound (6-methylflavone) that can block responses to an intensely bitter-tasting anti-human immunodeficiency virus (HIV) drug, tenofovir alafenamide (TAF), using a primary human taste bud epithelial cell culture as a screening platform. Specifically, TAS2R39 and TAS2R1 are the main type 2 taste receptors responding to TAF observed via heterologously expressing specific TAS2R receptors into HEK293 cells. In this assay, 6-methylflavone blocked the responses of TAS2R39 to TAF. In human sensory testing, 8 of 16 subjects showed reduction in perceived bitterness of TAF after pretreating (or "prerinsing") with 6-methylflavone and mixing 6-methylflavone with TAF. Bitterness was completely and reliably blocked in two of these subjects. These data demonstrate that a combined approach of human taste cell culture-based screening, receptor-specific assays, and human psychophysical testing can successfully discover molecules for blocking perceived bitterness of pharmaceuticals, such as the HIV therapeutic TAF. Our hope is to use bitter taste blockers to increase medical compliance with these vital medicines. SIGNIFICANCE STATEMENT: Identification of a small molecule that inhibits bitter taste from tenofovir alafenamide may increase the compliance in treating children with human immunodeficiency virus infections.


Assuntos
Adenina/análogos & derivados , Aromatizantes/administração & dosagem , Aromatizantes/química , Papilas Gustativas/efeitos dos fármacos , Paladar/efeitos dos fármacos , Adenina/efeitos adversos , Adenina/química , Adulto , Antivirais/efeitos adversos , Antivirais/química , Linhagem Celular , Feminino , Flavonas/administração & dosagem , Flavonas/química , Células HEK293 , Humanos , Masculino , Receptores de Superfície Celular/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Papilas Gustativas/metabolismo
9.
Int J Mol Sci ; 22(7)2021 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-33805444

RESUMO

Macrophage colony-stimulating factor (M-CSF or CSF-1) is known to have a broad range of actions on myeloid cells maturation, including the regulation of macrophage differentiation, proliferation and survival. Macrophages generated by M-CSF stimulus have been proposed to be alternatively activated or M2 phenotype. M-CSF is commonly overexpressed by tumors and is also known to enhance tumor growth and aggressiveness via stimulating pro-tumor activities of tumor-associated macrophages (TAMs). Currently, inhibition of CSF-1/CSF-1R interaction by therapeutic antibody to deplete TAMs and their pro-tumor functions is becoming a prevalent strategy in cancer therapy. However, its antitumor activity shows a limited single-agent effect. Therefore, macrophages in response to M-CSF interruption are pending for further investigation. To achieve this study, bone marrow derived macrophages were generated in vitro by M-CSF stimulation for 7 days and then continuously grown until day 21 in M-CSF absence. A selective pressure for cell survival was initiated after withdrawal of M-CSF. The surviving cells were more prone to M2-like phenotype, even after receiving interleukin-4 (IL-4) stimulation. The transcriptome analysis unveiled that endogenous CSF-1 level was dramatically up-regulated and numerous genes downstream to CSF-1 covering tumor necrosis factor (TNF), ras-related protein 1 (Rap1) and phosphatidylinositol 3-kinase (PI3K)-protein kinase B (AKT) signaling pathway were significantly modulated, especially for proliferation, migration and adhesion. Moreover, the phenomenal increase of miR-21-5p and genes related to pro-tumor activity were observed in parallel. In summary, withholding of CSF-1/CSF-1R interaction would rather augment than suspend the M-CSF-driven pro-tumor activities of M2 macrophages in a long run.


Assuntos
Fator Estimulador de Colônias de Macrófagos/farmacologia , Macrófagos/efeitos dos fármacos , Animais , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Reprogramação Celular/efeitos dos fármacos , Reprogramação Celular/fisiologia , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Lectinas Tipo C/metabolismo , Fator Estimulador de Colônias de Macrófagos/metabolismo , Macrófagos/metabolismo , Lectinas de Ligação a Manose/metabolismo , Camundongos Endogâmicos C57BL , Receptores de Superfície Celular/metabolismo , Receptores de Fator Estimulador das Colônias de Granulócitos e Macrófagos/metabolismo , Macrófagos Associados a Tumor/efeitos dos fármacos , Macrófagos Associados a Tumor/patologia
10.
Nature ; 592(7854): 414-420, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33828296

RESUMO

Critical periods-brief intervals during which neural circuits can be modified by activity-are necessary for proper neural circuit assembly. Extended critical periods are associated with neurodevelopmental disorders; however, the mechanisms that ensure timely critical period closure remain poorly understood1,2. Here we define a critical period in a developing Drosophila motor circuit and identify astrocytes as essential for proper critical period termination. During the critical period, changes in activity regulate dendrite length, complexity and connectivity of motor neurons. Astrocytes invaded the neuropil just before critical period closure3, and astrocyte ablation prolonged the critical period. Finally, we used a genetic screen to identify astrocyte-motor neuron signalling pathways that close the critical period, including Neuroligin-Neurexin signalling. Reduced signalling destabilized dendritic microtubules, increased dendrite dynamicity and impaired locomotor behaviour, underscoring the importance of critical period closure. Previous work defined astroglia as regulators of plasticity at individual synapses4; we show here that astrocytes also regulate motor circuit critical period closure to ensure proper locomotor behaviour.


Assuntos
Astrócitos/fisiologia , Período Crítico Psicológico , Drosophila melanogaster/citologia , Drosophila melanogaster/fisiologia , Vias Eferentes/fisiologia , Neurônios Motores/fisiologia , Plasticidade Neuronal/fisiologia , Animais , Moléculas de Adesão Celular Neuronais/metabolismo , Dendritos/fisiologia , Feminino , Locomoção/fisiologia , Masculino , Microtúbulos/metabolismo , Neurópilo/fisiologia , Receptores de Superfície Celular/metabolismo , Transdução de Sinais , Sinapses/fisiologia , Fatores de Tempo
11.
J Med Chem ; 64(9): 5226-5251, 2021 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-33905258

RESUMO

Positron emission tomography (PET) is useful for noninvasive in vivo visualization of disease-related receptors, for evaluation of receptor occupancy to determine an appropriate drug dosage, and for proof-of-concept of drug candidates in translational research. For these purposes, the specificity of the PET tracer for the target receptor is critical. Here, we review work in this area, focusing on the chemical structures of reported PET tracers, their Ki/Kd values, and the physical properties relevant to target receptor selectivity. Among these physical properties, such as cLogP, cLogD, molecular weight, topological polar surface area, number of hydrogen bond donors, and pKa, we focus especially on LogD and LogP as important physical properties that can be easily compared across a range of studies. We discuss the success of PET tracers in evaluating receptor occupancy and consider likely future developments in the field.


Assuntos
Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos/metabolismo , Receptores de Superfície Celular/metabolismo , Humanos , Interações Hidrofóbicas e Hidrofílicas , Neoplasias/diagnóstico por imagem , Ligação Proteica , Compostos Radiofarmacêuticos/química , Receptores de Canabinoides/química , Receptores de Canabinoides/metabolismo , Receptores de Superfície Celular/química , Receptores Colinérgicos/química , Receptores Colinérgicos/metabolismo , Receptores de Progesterona/química , Receptores de Progesterona/metabolismo
12.
Science ; 372(6540)2021 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-33888612

RESUMO

Cell-cell interactions control the physiology and pathology of the central nervous system (CNS). To study astrocyte cell interactions in vivo, we developed rabies barcode interaction detection followed by sequencing (RABID-seq), which combines barcoded viral tracing and single-cell RNA sequencing (scRNA-seq). Using RABID-seq, we identified axon guidance molecules as candidate mediators of microglia-astrocyte interactions that promote CNS pathology in experimental autoimmune encephalomyelitis (EAE) and, potentially, multiple sclerosis (MS). In vivo cell-specific genetic perturbation EAE studies, in vitro systems, and the analysis of MS scRNA-seq datasets and CNS tissue established that Sema4D and Ephrin-B3 expressed in microglia control astrocyte responses via PlexinB2 and EphB3, respectively. Furthermore, a CNS-penetrant EphB3 inhibitor suppressed astrocyte and microglia proinflammatory responses and ameliorated EAE. In summary, RABID-seq identified microglia-astrocyte interactions and candidate therapeutic targets.


Assuntos
Astrócitos/fisiologia , Comunicação Celular , Sistema Nervoso Central/patologia , Encefalomielite Autoimune Experimental/fisiopatologia , Microglia/fisiologia , Esclerose Múltipla/fisiopatologia , Análise de Célula Única , Animais , Antígenos CD/metabolismo , Encéfalo/patologia , Encéfalo/fisiopatologia , Sistema Nervoso Central/fisiopatologia , Encefalomielite Autoimune Experimental/patologia , Efrina-B3/metabolismo , Herpesvirus Suídeo 1/genética , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Esclerose Múltipla/patologia , NF-kappa B/metabolismo , Proteínas do Tecido Nervoso/metabolismo , RNA-Seq , Espécies Reativas de Oxigênio/metabolismo , Receptor EphB3/antagonistas & inibidores , Receptor EphB3/metabolismo , Receptores de Superfície Celular/metabolismo , Semaforinas/metabolismo , Transdução de Sinais , Linfócitos T/fisiologia , Serina-Treonina Quinases TOR/metabolismo
13.
BMC Plant Biol ; 21(1): 196, 2021 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-33892630

RESUMO

BACKGROUND: The vascular system of plants consists of two main tissue types, xylem and phloem. These tissues are organized into vascular bundles that are arranged into a complex network running through the plant that is essential for the viability of land plants. Despite their obvious importance, the genes involved in the organization of vascular tissues remain poorly understood in grasses. RESULTS: We studied in detail the vascular network in stems from the model grass Brachypodium distachyon (Brachypodium) and identified a large set of genes differentially expressed in vascular bundles versus parenchyma tissues. To decipher the underlying molecular mechanisms of vascularization in grasses, we conducted a forward genetic screen for abnormal vasculature. We identified a mutation that severely affected the organization of vascular tissues. This mutant displayed defects in anastomosis of the vascular network and uncommon amphivasal vascular bundles. The causal mutation is a premature stop codon in ERECTA, a LRR receptor-like serine/threonine-protein kinase. Mutations in this gene are pleiotropic indicating that it serves multiple roles during plant development. This mutant also displayed changes in cell wall composition, gene expression and hormone homeostasis. CONCLUSION: In summary, ERECTA has a pleiotropic role in Brachypodium. We propose a major role of ERECTA in vasculature anastomosis and vascular tissue organization in Brachypodium.


Assuntos
Brachypodium/genética , Floema/crescimento & desenvolvimento , Proteínas de Plantas/genética , Proteínas Serina-Treonina Quinases/genética , Receptores de Superfície Celular/genética , Xilema/crescimento & desenvolvimento , Brachypodium/crescimento & desenvolvimento , Brachypodium/metabolismo , Floema/genética , Proteínas de Plantas/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Receptores de Superfície Celular/metabolismo , Xilema/genética
14.
Int J Mol Sci ; 22(9)2021 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-33925787

RESUMO

Low aerobic capacity is considered to be a risk factor for stroke, while the mechanisms underlying the phenomenon are still unclear. The current study looked into the impacts of different aerobic capacities on early brain injury in a subarachnoid hemorrhage (SAH) model using rats bred for high and low aerobic capacity (high-capacity runners, HCR; low-capacity runners, LCR). SAH was modeled with endovascular perforation in HCR and LCR rats. Twenty-four hours after SAH, the rats underwent behavioral testing and MRI, and were then euthanized. The brains were used to investigate ventricular wall damage, blood-brain barrier breakdown, oxidative stress, and hemoglobin scavenging. The LCR rats had worse SAH grades (p < 0.01), ventricular dilatation (p < 0.01), ventricular wall damage (p < 0.01), and behavioral scores (p < 0.01). The periventricular expression of HO-1 and CD163 was significantly increased in LCR rats (p < 0.01 each). CD163-positive cells were co-localized with HO-1-positive cells. The LCR rats had greater early brain injuries than HCR rats. The LCR rats had more serious SAH and extensive ventricular wall damage that evolved more frequently into hydrocephalus. This may reflect changes in iron handling and neuroinflammation.


Assuntos
Hidrocefalia/metabolismo , Estresse Oxidativo , Corrida/fisiologia , Hemorragia Subaracnóidea/complicações , Animais , Antígenos CD/metabolismo , Antígenos de Diferenciação Mielomonocítica/metabolismo , Encéfalo/metabolismo , Modelos Animais de Doenças , Heme Oxigenase-1/metabolismo , Imageamento por Ressonância Magnética , Ratos , Receptores de Superfície Celular/metabolismo , Acidente Vascular Cerebral/complicações
15.
Eur J Pharmacol ; 901: 174097, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-33848540

RESUMO

Renal fibrosis is the common pathological hallmark of chronic kidney disease, and SET domain containing lysine methyltransferase 7 (SETD7) promote considerably renal fibrosis. However, the signaling mechanisms underlying SETD7 driving renal fibrosis are not fully understood. Here, we investigated the role of SETD7 in M2 macrophages-myofibroblasts transition and the myeloid fibroblasts activation in folic acid and obstruction-induced renal fibrosis. Mice treated with PFI-2, an inhibitor of SETD7, presented less bone marrow-derived myofibroblasts, fewer CD206+/α-smooth muscle actin + cells and developed less renal fibrosis (P<0.01). Furthermore, SETD7 inhibition reduced the infiltration of inflammatory cells and decreased the production of pro-inflammatory cytokines and chemokines in the kidneys after folic acid treatment (P<0.01). Finally, SETD7 inhibition suppressed the accumulation of NF-κB p65+ cells in folic acid nephropathy (P<0.01). Taken together, SETD7 mediates M2 macrophages-myofibroblasts transition, bone marrow-derived myofibroblasts activation, and inflammation response in the development of renal fibrosis.


Assuntos
Inibidores Enzimáticos/uso terapêutico , Ácido Fólico/farmacologia , Histona-Lisina N-Metiltransferase/antagonistas & inibidores , Nefropatias/tratamento farmacológico , Rim/patologia , Animais , Fibroblastos/efeitos dos fármacos , Fibrose , Nefropatias/induzido quimicamente , Nefropatias/patologia , Testes de Função Renal , Lectinas Tipo C/metabolismo , Macrófagos/efeitos dos fármacos , Masculino , Lectinas de Ligação a Manose/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Receptores de Superfície Celular/metabolismo , Fator de Transcrição RelA/efeitos dos fármacos
16.
Int J Mol Sci ; 22(6)2021 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-33809946

RESUMO

Sperm fertility ability may be modulated by different molecular systems, such as the renin-angiotensin system (RAS). Although renin is one of its most relevant peptides, the presence and role of the (pro)renin receptor (PRR) is completely unknown. We have proved for the first time the existence of PRR and its transcript in human sperm by western blot and RT-PCR. Immunofluorescence studies showed that this receptor is mainly located in the apical region over the acrosome and in the postacrosomal region of the sperm head and along the sperm tail. In addition, this prospective cohort study also proves that semen samples with higher percentages of PRR-positive spermatozoa are associated with poor sperm motility, worse blastocyst development and no-viable blastocysts. Our results provide insight into how PRR play a negative role in sperm physiology that it may condition human embryo quality and development. An in-depth understanding of the role of PRR in sperm fertility can help elucidate its role in male infertility, as well as establish biomarkers for the diagnosis or selection of sperm to use during assisted reproductive techniques.


Assuntos
Infertilidade Masculina/genética , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Espermatozoides/metabolismo , ATPases Vacuolares Próton-Translocadoras/genética , ATPases Vacuolares Próton-Translocadoras/metabolismo , Transferência Embrionária , Desenvolvimento Embrionário/genética , Feminino , Fertilização In Vitro , Expressão Gênica , Humanos , Nascido Vivo , Masculino , Gravidez , Resultado da Gravidez , Transporte Proteico , Análise do Sêmen
17.
Int J Nanomedicine ; 16: 2337-2356, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33790553

RESUMO

The development of monoclonal antibody treatments for successful tumor-targeted therapies took several decades. However, the efficacy of antibody-based therapy is still confined and desperately needs further improvement. Nanobodies are the recombinant variable domains of heavy-chain-only antibodies, with many unique properties such as small size (~15kDa), excellent solubility, superior stability, ease of manufacture, quick clearance from blood, and deep tissue penetration, which gain increasing acceptance as therapeutical tools and are considered also as building blocks for chimeric antigen receptors as well as for targeted drug delivery. Thus, one of the promising novel developments that may address the deficiency of monoclonal antibody-based therapies is the utilization of nanobodies. This article provides readers the significant factors that the structural and biochemical properties of nanobodies and the research progress on nanobodies in the fields of tumor treatment, as well as their application prospect.


Assuntos
Neoplasias/tratamento farmacológico , Anticorpos de Domínio Único/uso terapêutico , Animais , Ensaios Clínicos como Assunto , Terapia Combinada , Sistemas de Liberação de Medicamentos , Humanos , Receptores de Superfície Celular/metabolismo , Anticorpos de Domínio Único/química
18.
Int J Mol Sci ; 22(6)2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33803997

RESUMO

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has resulted in significant morbidity and mortality across the world, with no current effective treatments available. Recent studies suggest the possibility of a cytokine storm associated with severe COVID-19, similar to the biochemical profile seen in hemophagocytic lymphohistiocytosis (HLH), raising the question of possible benefits that could be derived from targeted immunosuppression in severe COVID-19 patients. We reviewed the literature regarding the diagnosis and features of HLH, particularly secondary HLH, and aimed to identify gaps in the literature to truly clarify the existence of a COVID-19 associated HLH. Diagnostic criteria such as HScore or HLH-2004 may have suboptimal performance in identifying COVID-19 HLH-like presentations, and criteria such as soluble CD163, NK cell activity, or other novel biomarkers may be more useful in identifying this entity.


Assuntos
COVID-19/complicações , COVID-19/diagnóstico , Linfo-Histiocitose Hemofagocítica/diagnóstico , Linfo-Histiocitose Hemofagocítica/etiologia , Antígenos CD/metabolismo , Antígenos de Diferenciação Mielomonocítica/metabolismo , Humanos , Células Matadoras Naturais/metabolismo , Receptores de Superfície Celular/metabolismo , Receptores de Interleucina-2/metabolismo , Sepse/etiologia
19.
Molecules ; 26(6)2021 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-33799482

RESUMO

Flavonoids are plant bioactives that are recognized as hormone-like polyphenols because of their similarity to the endogenous sex steroids 17ß-estradiol and testosterone, and to their estrogen- and androgen-like activity. Most efforts to verify flavonoid binding to nuclear receptors (NRs) and explain their action have been focused on ERα, while less attention has been paid to other nuclear and non-nuclear membrane androgen and estrogen receptors. Here, we investigate six flavonoids (apigenin, genistein, luteolin, naringenin, quercetin, and resveratrol) that are widely present in fruits and vegetables, and often used as replacement therapy in menopause. We performed comparative computational docking simulations to predict their capability of binding nuclear receptors ERα, ERß, ERRß, ERRγ, androgen receptor (AR), and its variant ART877A and membrane receptors for androgens, i.e., ZIP9, GPRC6A, OXER1, TRPM8, and estrogens, i.e., G Protein-Coupled Estrogen Receptor (GPER). In agreement with data reported in literature, our results suggest that these flavonoids show a relevant degree of complementarity with both estrogen and androgen NR binding sites, likely triggering genomic-mediated effects. It is noteworthy that reliable protein-ligand complexes and estimated interaction energies were also obtained for some suggested estrogen and androgen membrane receptors, indicating that flavonoids could also exert non-genomic actions. Further investigations are needed to clarify flavonoid multiple genomic and non-genomic effects. Caution in their administration could be necessary, until the safe assumption of these natural molecules that are largely present in food is assured.


Assuntos
Androgênios/metabolismo , Núcleo Celular/metabolismo , Estrogênios/metabolismo , Flavonoides/metabolismo , Ligação Proteica/fisiologia , Receptores de Superfície Celular/metabolismo , Estradiol/metabolismo , Receptor alfa de Estrogênio/metabolismo , Receptor beta de Estrogênio/metabolismo , Humanos , Simulação de Acoplamento Molecular , Receptores de Estrogênio , Testosterona/metabolismo
20.
Int J Mol Sci ; 22(6)2021 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-33803025

RESUMO

The liver mass constitutes hepatocytes expressing receptors for vitamin B12 (B12)-bound transporters in circulation. However, intrahepatic and circulating B12 interrelationship levels remain unclear. We assessed the intracellular B12 levels at various circulating B12 concentrations in human HepG2 cell-line and liver tissue levels of B12 in the C57BL/6 mouse model. In HepG2 cells treated with a range of B12 concentrations, the intracellular and circulatory B12 levels, transcript and protein levels of B12 receptor (CD320) and transporter (TCN2) were determined using immunoassays, qRT-PCR and Western blot, respectively. Similar assessments were done in plasma and liver tissue of C57BL/6 mice, previously fed a diet of either a high or low B12 (30.82 µg B12/kg and 7.49 µg B12/kg, respectively) for 8-10 weeks. The physiological B12 status (0.15-1 nM) resulted in increased levels of intracellular B12 in HepG2 cells compared to supraphysiological levels of B12 (>1 nM). Gene and protein expression of CD320 and TCN2 were also higher at physiological levels of B12. Progressively increasing extracellular B12 to supraphysiological levels led to relative decreased levels of intracellular B12, lower expression of gene and protein levels of CD320 and TCN2. Similar results were observed in liver tissue from mice fed on a low B12 diet verses high B12 diet. These findings suggest that unlike supraphysiological B12, physiological levels of B12 in the extracellular media or circulation accelerates active transport of B12, and expression of CD320 and TCN2, resulting in higher relative uptake of B12 in hepatocytes.


Assuntos
Antígenos CD/metabolismo , Hepatócitos/metabolismo , Espaço Intracelular/metabolismo , Fígado/metabolismo , Receptores de Superfície Celular/metabolismo , Transcobalaminas/metabolismo , Vitamina B 12/metabolismo , Animais , Antígenos CD/genética , Células Hep G2 , Humanos , Camundongos , Camundongos Endogâmicos C57BL , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de Superfície Celular/genética , Transcobalaminas/genética
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