Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 8.408
Filtrar
1.
Int J Mol Sci ; 22(18)2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34576132

RESUMO

Although anti-cancer properties of the natural compound curcumin have been reported, low absorption and rapid metabolisation limit clinical use. The present study investigated whether irradiation with visible light may enhance the inhibitory effects of low-dosed curcumin on prostate cancer cell growth, proliferation, and metastasis in vitro. DU145 and PC3 cells were incubated with low-dosed curcumin (0.1-0.4 µg/mL) and subsequently irradiated with 1.65 J/cm2 visible light for 5 min. Controls remained untreated and/or non-irradiated. Cell growth, proliferation, apoptosis, adhesion, and chemotaxis were evaluated, as was cell cycle regulating protein expression (CDK, Cyclins), and integrins of the α- and ß-family. Curcumin or light alone did not cause any significant effects on tumor growth, proliferation, or metastasis. However, curcumin combined with light irradiation significantly suppressed tumor growth, adhesion, and migration. Phosphorylation of CDK1 decreased and expression of the counter-receptors cyclin A and B was diminished. Integrin α and ß subtypes were also reduced, compared to controls. Irradiation distinctly enhances the anti-tumor potential of curcumin in vitro and may hold promise in treating prostate cancer.


Assuntos
Curcumina/farmacologia , Luz , Neoplasias da Próstata/patologia , Apoptose/efeitos dos fármacos , Apoptose/efeitos da radiação , Adesão Celular/efeitos dos fármacos , Adesão Celular/efeitos da radiação , Ciclo Celular/efeitos dos fármacos , Ciclo Celular/efeitos da radiação , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Movimento Celular/efeitos da radiação , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/efeitos da radiação , Células Clonais , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Integrinas/metabolismo , Masculino , Metástase Neoplásica
2.
Nat Commun ; 12(1): 5581, 2021 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-34552085

RESUMO

Cancer cells depend on actin cytoskeleton rearrangement to carry out hallmark malignant functions including activation, proliferation, migration and invasiveness. Wiskott-Aldrich Syndrome protein (WASp) is an actin nucleation-promoting factor and is a key regulator of actin polymerization in hematopoietic cells. The involvement of WASp in malignancies is incompletely understood. Since WASp is exclusively expressed in hematopoietic cells, we performed in silico screening to identify small molecule compounds (SMCs) that bind WASp and promote its degradation. We describe here one such identified molecule; this WASp-targeting SMC inhibits key WASp-dependent actin processes in several types of hematopoietic malignancies in vitro and in vivo without affecting naïve healthy cells. This small molecule demonstrates limited toxicity and immunogenic effects, and thus, might serve as an effective strategy to treat specific hematopoietic malignancies in a safe and precisely targeted manner.


Assuntos
Antineoplásicos/metabolismo , Antineoplásicos/uso terapêutico , Neoplasias Hematológicas/tratamento farmacológico , Proteína da Síndrome de Wiskott-Aldrich/metabolismo , Actinas/metabolismo , Animais , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Proteínas do Citoesqueleto/metabolismo , Neoplasias Hematológicas/metabolismo , Neoplasias Hematológicas/patologia , Humanos , Integrinas/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Camundongos , Invasividade Neoplásica , Ligação Proteica/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas/metabolismo , Bibliotecas de Moléculas Pequenas/farmacocinética , Bibliotecas de Moléculas Pequenas/farmacologia , Bibliotecas de Moléculas Pequenas/uso terapêutico , Ubiquitinação/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
3.
Zhonghua Yi Xue Za Zhi ; 101(34): 2692-2697, 2021 Sep 14.
Artigo em Chinês | MEDLINE | ID: mdl-34510875

RESUMO

Objective: To elucidate the biological role and potential mechanism of integrin α5 (ITGA5) in gastric cancer (GC). Methods: From January 2019 to December 2020, 35 pairs of GC tissue [21 males and 14 females, aged (53.8±5.4) years] and matched adjacent tissue samples were collected from GC patients who underwent surgical resection in Zhejiang Provincial People's Hospital. GC and normal gastric mucosa cells were purchased from Beijing Biobw Biotech Company. Quantitative real-time PCR (qRT-PCR), immunohistochemistry, Western blotting were performed to detect the mRNA and protein expression levels of ITGA5, cell adhesion-related genes (pFAK, pSrc, aRac1) in GC cells. Cell Counting Kit-8 (CCK-8), Transwell invasion, wound healing and cell adhesion assays were conducted for GC cell phenotype detection. Results: ITGA5 was highly expressed in GC compared with normal gastric mucosa cells (relative expression increased from 1.00±0.26 to 1.23±0.27,P<0.05). In addition, ITGA5 overexpression promoted the cell proliferation [from (1.14±0.14) OD to (1.61±0.14) OD], migration ability [from (20.3±2.3)% to (56.4±6.1)%], invasion ability (from 144.0±4.6 to 216.7±6.6), and adhesion ability of matrix protein (from 99.0±8.5 to 152.0±12.3) through FAK/Src/Rac1 signaling pathway in GC.(all P<0.05) Conclusions: ITGA5 acts as a cancer-promoting factor in GC. The current study provides theoretical evidence for probing the novel molecular targets for the treatment of GC.


Assuntos
Integrina alfa5 , Integrinas/metabolismo , Neoplasias Gástricas , Movimento Celular , Proliferação de Células , Feminino , Humanos , Integrina alfa5/metabolismo , Masculino , Invasividade Neoplásica , Transdução de Sinais , Proteínas rac1 de Ligação ao GTP/metabolismo
4.
Nat Commun ; 12(1): 4693, 2021 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-34344862

RESUMO

Many cellular processes, including cell division, development, and cell migration require spatially and temporally coordinated forces transduced by cell-surface receptors. Nucleic acid-based molecular tension probes allow one to visualize the piconewton (pN) forces applied by these receptors. Building on this technology, we recently developed molecular force microscopy (MFM) which uses fluorescence polarization to map receptor force orientation with diffraction-limited resolution (~250 nm). Here, we show that structured illumination microscopy (SIM), a super-resolution technique, can be used to perform super-resolution MFM. Using SIM-MFM, we generate the highest resolution maps of both the magnitude and orientation of the pN traction forces applied by cells. We apply SIM-MFM to map platelet and fibroblast integrin forces, as well as T cell receptor forces. Using SIM-MFM, we show that platelet traction force alignment occurs on a longer timescale than adhesion. Importantly, SIM-MFM can be implemented on any standard SIM microscope without hardware modifications.


Assuntos
Microscopia de Fluorescência/métodos , Receptores de Superfície Celular/metabolismo , Animais , Fenômenos Biomecânicos , Plaquetas/metabolismo , Linfócitos T CD8-Positivos , Corantes Fluorescentes/metabolismo , Humanos , Integrinas/metabolismo , Camundongos , Sondas Moleculares/metabolismo , Células NIH 3T3 , Paxilina/metabolismo , Receptores de Antígenos de Linfócitos T/metabolismo , Imagem com Lapso de Tempo
5.
Life Sci ; 284: 119881, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34389403

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an infectious disease that has spread worldwide. Current treatments are limited in both availability and efficacy, such that improving our understanding of the factors that facilitate infection is urgently needed to more effectively treat infected individuals and to curb the pandemic. We and others have previously demonstrated the significance of interactions between the SARS-CoV-2 spike protein, integrin α5ß1, and human ACE2 to facilitate viral entry into host cells in vitro. We previously found that inhibition of integrin α5ß1 by the clinically validated small peptide ATN-161 inhibits these spike protein interactions and cell infection in vitro. In continuation with our previous findings, here we have further evaluated the therapeutic potential of ATN-161 on SARS-CoV-2 infection in k18-hACE2 transgenic (SARS-CoV-2 susceptible) mice in vivo. We discovered that treatment with single or repeated intravenous doses of ATN-161 (1 mg/kg) within 48 h after intranasal inoculation with SARS-CoV-2 lead to a reduction of lung viral load, viral immunofluorescence, and improved lung histology in a majority of mice 72 h post-infection. Furthermore, ATN-161 reduced SARS-CoV-2-induced increased expression of lung integrin α5 and αv (an α5-related integrin that has also been implicated in SARS-CoV-2 interactions) as well as the C-X-C motif chemokine ligand 10 (Cxcl10), further supporting the potential involvement of these integrins, and the anti-inflammatory potential of ATN-161, respectively, in SARS-CoV-2 infection. To the best of our knowledge, this is the first study demonstrating the potential therapeutic efficacy of targeting integrin α5ß1 in SARS-CoV-2 infection in vivo and supports the development of ATN-161 as a novel SARS-CoV-2 therapy.


Assuntos
Enzima de Conversão de Angiotensina 2/metabolismo , COVID-19/tratamento farmacológico , COVID-19/prevenção & controle , Oligopeptídeos/uso terapêutico , SARS-CoV-2/fisiologia , Alanina Transaminase/metabolismo , Animais , Aspartato Aminotransferases/metabolismo , COVID-19/virologia , Genoma Viral , Humanos , Integrinas/metabolismo , Fígado/enzimologia , Fígado/patologia , Pulmão/patologia , Pulmão/virologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Oligopeptídeos/farmacologia , SARS-CoV-2/genética , Coloração e Rotulagem , Carga Viral/genética
6.
Cells ; 10(7)2021 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-34359873

RESUMO

Integrins belong to a group of cell adhesion molecules (CAMs) which is a large group of membrane-bound proteins. They are responsible for cell attachment to the extracellular matrix (ECM) and signal transduction from the ECM to the cells. Integrins take part in many other biological activities, such as extravasation, cell-to-cell adhesion, migration, cytokine activation and release, and act as receptors for some viruses, including severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2). They play a pivotal role in cell proliferation, migration, apoptosis, tissue repair and are involved in the processes that are crucial to infection, inflammation and angiogenesis. Integrins have an important part in normal development and tissue homeostasis, and also in the development of pathological processes in the eye. This review presents the available evidence from human and animal research into integrin structure, classification, function and their role in inflammation, infection and angiogenesis in ocular diseases. Integrin receptors and ligands are clinically interesting and may be promising as new therapeutic targets in the treatment of some eye disorders.


Assuntos
Oftalmopatias/metabolismo , Inflamação/metabolismo , Integrinas/metabolismo , Neovascularização Patológica/metabolismo , Animais , COVID-19/metabolismo , COVID-19/patologia , Adesão Celular , Matriz Extracelular/metabolismo , Matriz Extracelular/patologia , Oftalmopatias/patologia , Humanos , Inflamação/patologia , Integrinas/análise , Neovascularização Patológica/patologia , SARS-CoV-2/metabolismo
7.
Int J Mol Sci ; 22(16)2021 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-34445386

RESUMO

Understanding the biological and morphological reactions of human cells towards different dentinal derivate grafting materials is fundamental for choosing the type of dentin for specific clinical situations. This study aimed to evaluate human periodontal ligament fibroblasts (hPLF) cells exposed to different dentinal derivates particles. The study design included the in vitro evaluation of mineralized dentine (SG), deproteinized and demineralized dentine (DDP), and demineralized dentine (TT) as test materials and of deproteinized bovine bone (BIOS) as the positive control material. The materials were kept with the hPLF cell line, and the evaluations were made after 24 h, 72 h, and 7 days of in vitro culture. The evaluated outcomes were proliferation by using XTT assays, the morphological characteristics by light microscopy (LM) and by the use of scanning electron microscopy (SEM), and adhesion by using confocal microscopy (CLSM). Overall, the experimental materials induced a positive response of the hPLFs in terms of proliferation and adhesion. The XTT assay showed the TT, and the SG induced significant growth compared to the negative control at 7 days follow-up. The morphological data supported the XTT assay: the LM observations showed the presence of densely packed cells with a modified shape; the SEM observations allowed the assessment of how fibroblasts exposed to DDP and TT presented cytoplasmatic extensions; and SG and BIOS also presented the thickening of the cellular membrane. The CLMS observations showed the expression of the proliferative marker, as well as and the expression of cytoskeletal elements involved in the adhesion process. In particular, the vinculin and integrin signals were stronger at 72 h, while the actin signal remained constantly expressed in all the follow-up of the sample exposed to SG material. The integrin signal was stronger at 72 h, and the vinculin and actin signals were stronger at 7 days follow-up in the sample exposed to DDP material. The vinculin and integrin signals were stronger at 72 h follow-up in the sample exposed to TT material; vinculin and integrin signals appear stronger at 24 h follow-up in the sample exposed to BIOS material. These data confirmed how dentinal derivates present satisfying biocompatibility and high conductivity and inductivity properties fundamental in the regenerative processes. Furthermore, the knowledge of the effects of the dentin's degree of mineralization on cellular behavior will help clinicians choose the type of dentine derivates material according to the required clinical situation.


Assuntos
Biomarcadores/metabolismo , Substitutos Ósseos/farmacologia , Dentina/química , Ligamento Periodontal/citologia , Animais , Substitutos Ósseos/química , Bovinos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Humanos , Integrinas/metabolismo , Teste de Materiais , Microscopia Confocal , Microscopia Eletrônica de Varredura , Ligamento Periodontal/efeitos dos fármacos , Ligamento Periodontal/metabolismo , Vinculina/metabolismo
8.
Cell Mol Life Sci ; 78(17-18): 6087-6104, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34296319

RESUMO

Different types of multinucleated giant cells (MGCs) of myeloid origin have been described; osteoclasts are the most extensively studied because of their importance in bone homeostasis. MGCs are formed by cell-to-cell fusion, and most types have been observed in pathological conditions, especially in infectious and non-infectious chronic inflammatory contexts. The precise role of the different MGCs and the mechanisms that govern their formation remain poorly understood, likely due to their heterogeneity. First, we will introduce the main populations of MGCs derived from the monocyte/macrophage lineage. We will then discuss the known molecular actors mediating the early stages of fusion, focusing on cell-surface receptors involved in the cell-to-cell adhesion steps that ultimately lead to multinucleation. Given that cell-to-cell fusion is a complex and well-coordinated process, we will also describe what is currently known about the evolution of F-actin-based structures involved in macrophage fusion, i.e., podosomes, zipper-like structures, and tunneling nanotubes (TNT). Finally, the localization and potential role of the key fusion mediators related to the formation of these F-actin structures will be discussed. This review intends to present the current status of knowledge of the molecular and cellular mechanisms supporting multinucleation of myeloid cells, highlighting the gaps still existing, and contributing to the proposition of potential disease-specific MGC markers and/or therapeutic targets.


Assuntos
Adesão Celular , Células Gigantes/metabolismo , Células Mieloides/metabolismo , Podossomos/metabolismo , Células Gigantes/citologia , Humanos , Integrinas/metabolismo , Macrófagos/citologia , Macrófagos/metabolismo , Células Mieloides/citologia , Células Mieloides/ultraestrutura , Osteoclastos/citologia , Osteoclastos/metabolismo , Osteogênese , Receptores Imunológicos/metabolismo
9.
FEBS Lett ; 595(17): 2257-2270, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34278574

RESUMO

HIV preferentially infects α4 ß7 + CD4 T cells, forming latent reservoirs that contribute to HIV persistence during antiretroviral therapy. However, the properties of α4 ß7 + CD4 T cells in blood and mucosal compartments remain understudied. Employing two distinct models of HIV infection, HIV-infected humans and simian-human immunodeficiency virus (SHIV)-infected rhesus macaques, we show that α4 ß7 + CD4 T cells in blood are enriched for genes regulating cell cycle progression and cellular metabolism. Unlike their circulating counterparts, rectal α4 ß7 + CD4 T cells exhibited a core tissue-residency gene expression program. These features were conserved across primate species, indicating that the environment influences memory T-cell transcriptional networks. Our findings provide an important molecular foundation for understanding the role of α4 ß7 in HIV infection.


Assuntos
Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD4-Positivos/virologia , Infecções por HIV/sangue , Integrinas/metabolismo , Adulto , Animais , COVID-19/sangue , COVID-19/virologia , Ciclo Celular , Proliferação de Células , Mucosa Gástrica/citologia , Mucosa Gástrica/virologia , Regulação da Expressão Gênica , Humanos , Imunização , Macaca mulatta , Masculino , Síndrome de Imunodeficiência Adquirida dos Símios/sangue , Síndrome de Imunodeficiência Adquirida dos Símios/virologia
10.
Int J Mol Sci ; 22(12)2021 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-34199292

RESUMO

Giant unilamellar vesicles (GUV) are powerful tools to explore physics and biochemistry of the cell membrane in controlled conditions. For example, GUVs were extensively used to probe cell adhesion, but often using non-physiological linkers, due to the difficulty of incorporating transmembrane adhesion proteins into model membranes. Here we describe a new protocol for making GUVs incorporating the transmembrane protein integrin using gel-assisted swelling. We report an optimised protocol, enumerating the pitfalls encountered and precautions to be taken to maintain the robustness of the protocol. We characterise intermediate steps of small proteoliposome formation and the final formed GUVs. We show that the integrin molecules are successfully incorporated and are functional.


Assuntos
Géis/química , Integrinas/metabolismo , Lipossomas Unilamelares/química , Adesão Celular , Fluorescência , Humanos , Bicamadas Lipídicas/metabolismo , Lipídeos/química , Tamanho da Partícula
11.
Am J Physiol Cell Physiol ; 321(2): C308-C316, 2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-34133240

RESUMO

Leukocyte recruitment is a critical step in the pathogenesis of inflammatory and immunological responses. Cell adhesion molecules (CAMs) are involved in controlling cell movements and the recruitment process, and the integrin family of CAMs plays a key role. During cell movement, integrin function is dynamically and precisely regulated. However, this balance might be broken under pathological conditions. Thus, the functional regulation and molecular mechanisms of integrins related to diseases are often a focus of research. Integrin ß2 is one of the most commonly expressed integrins in leukocytes that mediate leukocyte adhesion and migration, and it plays an important role in immune responses and inflammation. In this review, we focus on specific functions of integrin ß2 in leukocyte recruitment, the conformational changes and signal transduction of integrin ß2 activation, the similarities between murine and human factors, and how new insights into these processes can inform future therapies for inflammation and immune diseases.


Assuntos
Movimento Celular/fisiologia , Integrinas/metabolismo , Leucócitos/metabolismo , Transdução de Sinais/fisiologia , Animais , Adesão Celular/fisiologia , Humanos , Inflamação/metabolismo , Leucócitos/imunologia
12.
Elife ; 102021 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-34169835

RESUMO

Integrin adhesion complexes regulate cytoskeletal dynamics during cell migration. Adhesion activates phosphorylation of integrin-associated signaling proteins, including Cas (p130Cas, BCAR1), by Src-family kinases. Cas regulates leading-edge protrusion and migration in cooperation with its binding partner, BCAR3. However, it has been unclear how Cas and BCAR3 cooperate. Here, using normal epithelial cells, we find that BCAR3 localization to integrin adhesions requires Cas. In return, Cas phosphorylation, as well as lamellipodia dynamics and cell migration, requires BCAR3. These functions require the BCAR3 SH2 domain and a specific phosphorylation site, Tyr 117, that is also required for BCAR3 downregulation by the ubiquitin-proteasome system. These findings place BCAR3 in a co-regulatory positive-feedback circuit with Cas, with BCAR3 requiring Cas for localization and Cas requiring BCAR3 for activation and downstream signaling. The use of a single phosphorylation site in BCAR3 for activation and degradation ensures reliable negative feedback by the ubiquitin-proteasome system.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Proteína Substrato Associada a Crk/genética , Fatores de Troca do Nucleotídeo Guanina/genética , Pseudópodes/metabolismo , Transdução de Sinais , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Adesão Celular , Linhagem Celular , Proteína Substrato Associada a Crk/metabolismo , Células Epiteliais , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Humanos , Integrinas/metabolismo , Fosforilação , Domínios de Homologia de src
13.
Int J Mol Sci ; 22(10)2021 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-34069904

RESUMO

Biological signals are sensed by their respective receptors and are transduced and processed by a sophisticated intracellular signaling network leading to a signal-specific cellular response. Thereby, the response to the signal depends on the strength, the frequency, and the duration of the stimulus as well as on the subcellular signal progression. Optogenetic tools are based on genetically encoded light-sensing proteins facilitating the precise spatiotemporal control of signal transduction pathways and cell fate decisions in the absence of natural ligands. In this review, we provide an overview of optogenetic approaches connecting light-regulated protein-protein interaction or caging/uncaging events with steering the function of signaling proteins. We briefly discuss the most common optogenetic switches and their mode of action. The main part deals with the engineering and application of optogenetic tools for the control of transmembrane receptors including receptor tyrosine kinases, the T cell receptor and integrins, and their effector proteins. We also address the hallmarks of optogenetics, the spatial and temporal control of signaling events.


Assuntos
Optogenética/métodos , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Animais , Comunicação Celular/fisiologia , Diferenciação Celular/fisiologia , Humanos , Integrinas/metabolismo , Luz , Receptores Proteína Tirosina Quinases/metabolismo
14.
Int J Mol Sci ; 22(11)2021 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-34073992

RESUMO

Angiogenesis is an active process, regulating new vessel growth, and is crucial for the survival and growth of tumours next to other complex factors in the tumour microenvironment. We present possible molecular imaging approaches for tumour vascularisation and vitality, focusing on radiopharmaceuticals (tracers). Molecular imaging in general has become an integrated part of cancer therapy, by bringing relevant insights on tumour angiogenic status. After a structured PubMed search, the resulting publication list was screened for oncology related publications in animals and humans, disregarding any cardiovascular findings. The tracers identified can be subdivided into direct targeting of angiogenesis (i.e., vascular endothelial growth factor, laminin, and fibronectin) and indirect targeting (i.e., glucose metabolism, hypoxia, and matrix metallo-proteases, PSMA). Presenting pre-clinical and clinical data of most tracers proposed in the literature, the indirect targeting agents are not 1:1 correlated with angiogenesis factors but do have a strong prognostic power in a clinical setting, while direct targeting agents show most potential and specificity for assessing tumour vascularisation and vitality. Within the direct agents, the combination of multiple targeting tracers into one agent (multimers) seems most promising. This review demonstrates the present clinical applicability of indirect agents, but also the need for more extensive research in the field of direct targeting of angiogenesis in oncology. Although there is currently no direct tracer that can be singled out, the RGD tracer family seems to show the highest potential therefore we expect one of them to enter the clinical routine.


Assuntos
Oncologia/métodos , Imagem Molecular/métodos , Neoplasias/diagnóstico por imagem , Neovascularização Patológica/diagnóstico por imagem , Tomografia por Emissão de Pósitrons/métodos , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Animais , Biomarcadores Tumorais/metabolismo , Hipóxia Celular , Glucose/metabolismo , Humanos , Integrinas/metabolismo , Metaloproteinases da Matriz/metabolismo , Oncologia/instrumentação , Neoplasias/patologia , Neovascularização Patológica/patologia , Oligopeptídeos/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo
15.
Int J Mol Sci ; 22(10)2021 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-34067978

RESUMO

Galectin-3 (Gal-3) is a ß-galactoside-binding protein that influences various cell functions, including cell adhesion. We focused on the role of Gal-3 as an extracellular ligand mediating cell-matrix adhesion. We used human adipose tissue-derived stem cells and human umbilical vein endothelial cells that are promising for vascular tissue engineering. We found that these cells naturally contained Gal-3 on their surface and inside the cells. Moreover, they were able to associate with exogenous Gal-3 added to the culture medium. This association was reduced with a ß-galactoside LacdiNAc (GalNAcß1,4GlcNAc), a selective ligand of Gal-3, which binds to the carbohydrate recognition domain (CRD) in the Gal-3 molecule. This ligand was also able to detach Gal-3 newly associated with cells but not Gal-3 naturally present on cells. In addition, Gal-3 preadsorbed on plastic surfaces acted as an adhesion ligand for both cell types, and the cell adhesion was resistant to blocking with LacdiNAc. This result suggests that the adhesion was mediated by a binding site different from the CRD. The blocking of integrin adhesion receptors on cells with specific antibodies revealed that the cell adhesion to the preadsorbed Gal-3 was mediated, at least partially, by ß1 and αV integrins-namely α5ß1, αVß3, and αVß1 integrins.


Assuntos
Proteínas Sanguíneas/metabolismo , Adesão Celular , Junções Célula-Matriz/metabolismo , Galectinas/metabolismo , Células Endoteliais da Veia Umbilical Humana/fisiologia , Integrinas/metabolismo , Células-Tronco Mesenquimais/fisiologia , Sítios de Ligação , Células Cultivadas , Células Endoteliais da Veia Umbilical Humana/citologia , Humanos , Células-Tronco Mesenquimais/citologia , Ligação Proteica
16.
Cancer Imaging ; 21(1): 44, 2021 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-34187570

RESUMO

BACKGROUND: The motif RXDLXXL-based nanoprobes allow specific imaging of integrin αvß6, a protein overexpressed during tumorigenesis and tumor progression of various tumors. We applied a novel RXDLXXL-coupled cyclic arginine-glycine-aspartate (RGD) nonapeptide conjugated with ultrasmall superparamagnetic iron oxide nanoparticles (referred to as cFK-9-USPIO) for the application of integrin αvß6-targeted magnetic resonance (MR) molecular imaging for breast cancer. METHODS: A novel MR-targeted nanoprobe, cFK-9-USPIO, was synthesized by conjugating integrin αvß6-targeted peptide cFK-9 to N-amino (-NH2)-modified USPIO nanoparticles via a dehydration esterification reaction. Integrin αvß6-positive mouse breast cancer (4 T1) and integrin αvß6 negative human embryonic kidney 293 (HEK293) cell lines were incubated with cFK-9-AbFlour 647 (blocking group) or cFK-9-USPIO (experimental group), and subsequently imaged using laser scanning confocal microscopy (LSCM) and 3.0 Tesla magnetic resonance imaging (MRI) system. The affinity of cFK-9 targeting αvß6 was analyzed by calculating the mean fluorescent intensity in cells, and the nanoparticle targeting effect was measured by the reduction of T2 values in an in vitro MRI. The in vivo MRI capability of cFK-9-USPIO was investigated in 4 T1 xenograft mouse models. Binding of the targeted nanoparticles to αvß6-positive 4 T1 tumors was determined by ex vivo histopathology. RESULTS: In vitro laser scanning confocal microscopy (LSCM) imaging showed that the difference in fluorescence intensity between the targeting and blocking groups of 4 T1 cells was significantly greater than that in HEK293 cells (P < 0.05). The in vitro MRI demonstrated a more remarkable T2 reduction in 4 T1 cells than in HEK293 cells (P < 0.001). The in vivo MRI of 4 T1 xenograft tumor-bearing nude mice showed significant T2 reduction in tumors compared to controls. Prussian blue staining further confirmed that αvß6 integrin-targeted nanoparticles were specifically accumulated in 4 T1 tumors and notably fewer nanoparticles were detected in 4 T1 tumors of mice injected with control USPIO and HEK293 tumors of mice administered cFK-9-USPIO. CONCLUSIONS: Integrin αvß6-targeted nanoparticles have great potential for use in the detection of αvß6-overexpressed breast cancer with MR molecular imaging.


Assuntos
Antígenos de Neoplasias/metabolismo , Integrinas/metabolismo , Imageamento por Ressonância Magnética/métodos , Neoplasias Mamárias Experimentais/diagnóstico por imagem , Animais , Meios de Contraste/química , Dextranos/farmacologia , Feminino , Células HEK293 , Humanos , Nanopartículas de Magnetita , Camundongos , Camundongos Nus , Ensaios Antitumorais Modelo de Xenoenxerto
17.
Int J Nanomedicine ; 16: 3819-3832, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34121840

RESUMO

Introduction: Embryonic stem cells (ESCs) possess great application prospects in biological research and regenerative medicine, so it is important to obtain ESCs with excellent and stable cellular states during in vitro expansion. The feeder layer culture system with the addition of leukemia inhibitory factor (LIF) is currently applied in ESC cultures, but it has a series of disadvantages that could influence the culture efficiency and quality of the ESCs. With the development of nanotechnology, many studies have applied nanomaterials to optimize the stem cell culture system and regulate the fate of stem cells. In this study, we investigated the layer-number-dependent biofunction of graphene oxide (GO) on the pluripotency of ESCs from mice (mESCs). Methods: Single-layer GO (SGO) and multi-layer GO (MGO) were characterized and their effects on the cytotoxicity and self-renewal of mESCs were detected in vitro. The differentiation potentials of mESCs were identified through the formation of embryoid bodies and teratomas. The regulatory mechanism of GO was verified by blocking the target receptors on the surface of mESCs using antibodies. Results: Both SGO and MGO were biocompatible with mESCs, but only MGO effectively sustained their self-renewal and differentiation potential. In addition, GO influenced the cellular activities of mESCs by regulating the interactions between extracellular matrix proteins and integrins. Conclusion: This work demonstrates the layer-number-dependent effects of GO on regulating the cell behavior of mESCs and reveals the extracellular regulatory mechanism of this process.


Assuntos
Matriz Extracelular/metabolismo , Grafite/farmacologia , Integrinas/metabolismo , Células-Tronco Embrionárias Murinas/citologia , Células-Tronco Embrionárias Murinas/metabolismo , Animais , Apoptose/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Autorrenovação Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Matriz Extracelular/efeitos dos fármacos , Proteínas da Matriz Extracelular/metabolismo , Camundongos , Células-Tronco Embrionárias Murinas/efeitos dos fármacos , Células-Tronco Embrionárias Murinas/ultraestrutura , Estresse Oxidativo/efeitos dos fármacos
18.
Nat Cell Biol ; 23(6): 642-651, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34059812

RESUMO

In the last decade, DNA-based tension sensors have made significant contributions to the study of the importance of mechanical forces in many biological systems. Albeit successful, one shortcoming of these techniques is their inability to reversibly measure receptor forces in a higher regime (that is, >20 pN), which limits our understanding of the molecular details of mechanochemical transduction in living cells. Here, we developed a reversible shearing DNA-based tension probe (RSDTP) for probing molecular piconewton-scale forces between 4 and 60 pN transmitted by cells. Using these probes, we can easily distinguish the differences in force-bearing integrins without perturbing adhesion biology and reveal that a strong force-bearing integrin cluster can serve as a 'mechanical pivot' to maintain focal adhesion architecture and facilitate its maturation. The benefits of the RSDTP include a high dynamic range, reversibility and single-molecule sensitivity, all of which will facilitate a better understanding of the molecular mechanisms of mechanobiology.


Assuntos
Sondas de DNA/metabolismo , Adesões Focais/metabolismo , Integrinas/metabolismo , Mecanotransdução Celular , Microscopia de Fluorescência , Microscopia de Vídeo , Animais , Técnicas Biossensoriais , Adesão Celular , Movimento Celular , Sondas de DNA/genética , Corantes Fluorescentes/metabolismo , Adesões Focais/genética , Integrinas/genética , Camundongos , Células NIH 3T3 , Nanotecnologia , Conformação de Ácido Nucleico , Estresse Mecânico , Fatores de Tempo
19.
Front Immunol ; 12: 656452, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34017333

RESUMO

Inflammatory bowel diseases (IBDs), including Crohn's disease (CD) and ulcerative colitis (UC) are multifactorial diseases with still unknown aetiology and an increasing prevalence and incidence worldwide. Despite plentiful therapeutic options for IBDs, the lack or loss of response in certain patients demands the development of further treatments to tackle this unmet medical need. In recent years, the success of the anti-α4ß7 antibody vedolizumab highlighted the potential of targeting the homing of immune cells, which is now an important pillar of IBD therapy. Due to its complexity, leukocyte trafficking and the involved molecules offer a largely untapped resource for a plethora of potential therapeutic interventions. In this review, we aim to summarise current and future directions of specifically interfering with immune cell trafficking. We will comment on concepts of homing, retention and recirculation and particularly focus on the role of tissue-derived chemokines. Moreover, we will give an overview of the mode of action of drugs currently in use or still in the pipeline, highlighting their mechanisms and potential to reduce disease burden.


Assuntos
Movimento Celular/imunologia , Doenças Inflamatórias Intestinais/imunologia , Animais , Moléculas de Adesão Celular/antagonistas & inibidores , Moléculas de Adesão Celular/genética , Moléculas de Adesão Celular/metabolismo , Movimento Celular/efeitos dos fármacos , Movimento Celular/genética , Quimiocinas/antagonistas & inibidores , Quimiocinas/metabolismo , Suscetibilidade a Doenças/imunologia , Desenvolvimento de Medicamentos , Humanos , Doenças Inflamatórias Intestinais/metabolismo , Integrinas/antagonistas & inibidores , Integrinas/metabolismo , Leucócitos/efeitos dos fármacos , Leucócitos/imunologia , Leucócitos/metabolismo , Linfonodos/efeitos dos fármacos , Linfonodos/imunologia , Linfonodos/metabolismo , Terapia de Alvo Molecular , Receptores de Esfingosina-1-Fosfato/metabolismo , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Linfócitos T/metabolismo
20.
Development ; 148(10)2021 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-33999995

RESUMO

The focal adhesion protein Kindlin2 is essential for integrin activation, a process that is fundamental to cell-extracellular matrix adhesion. Kindlin 2 (Fermt2) is widely expressed in mouse embryos, and its absence causes lethality at the peri-implantation stage due to the failure to trigger integrin activation. The function of kindlin2 during embryogenesis has not yet been fully elucidated as a result of this early embryonic lethality. Here, we showed that kindlin2 is essential for neural crest (NC) formation in Xenopus embryos. Loss-of-function assays performed with kindlin2-specific morpholino antisense oligos (MOs) or with CRISPR/Cas9 techniques in Xenopus embryos severely inhibit the specification of the NC. Moreover, integrin-binding-deficient mutants of Kindlin2 rescued the phenotype caused by loss of kindlin2, suggesting that the function of kindlin2 during NC specification is independent of integrins. Mechanistically, we found that Kindlin2 regulates the fibroblast growth factor (FGF) pathway, and promotes the stability of FGF receptor 1. Our study reveals a novel function of Kindlin2 in regulating the FGF signaling pathway and provides mechanistic insights into the function of Kindlin2 during NC specification.


Assuntos
Fatores de Crescimento de Fibroblastos/metabolismo , Proteínas de Membrana/metabolismo , Crista Neural/embriologia , Proteínas de Xenopus/metabolismo , Xenopus laevis/embriologia , Animais , Sistemas CRISPR-Cas/genética , Linhagem Celular , Embrião não Mamífero/metabolismo , Desenvolvimento Embrionário/genética , Desenvolvimento Embrionário/fisiologia , Regulação da Expressão Gênica no Desenvolvimento/genética , Técnicas de Inativação de Genes , Células HEK293 , Células HeLa , Humanos , Integrinas/metabolismo , Proteínas de Membrana/genética , Morfolinos/genética , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/metabolismo , Transdução de Sinais/genética , Proteínas de Xenopus/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...