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1.
Arterioscler Thromb Vasc Biol ; 44(3): e82-e98, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38205640

RESUMO

BACKGROUND: Integrins mediate the adhesion, crawling, and migration of neutrophils during vascular inflammation. Thiol exchange is important in the regulation of integrin functions. ERp72 (endoplasmic reticulum-resident protein 72) is a member of the thiol isomerase family responsible for the catalysis of disulfide rearrangement. However, the role of ERp72 in the regulation of Mac-1 (integrin αMß2) on neutrophils remains elusive. METHODS: Intravital microscopy of the cremaster microcirculation was performed to determine in vivo neutrophil movement. Static adhesion, flow chamber, and flow cytometry were used to evaluate in vitro integrin functions. Confocal fluorescent microscopy and coimmunoprecipitation were utilized to characterize the interactions between ERp72 and Mac-1 on neutrophil surface. Cell-impermeable probes and mass spectrometry were used to label reactive thiols and identify target disulfide bonds during redox exchange. Biomembrane force probe was performed to quantitatively measure the binding affinity of Mac-1. A murine model of acute lung injury induced by lipopolysaccharide was utilized to evaluate neutrophil-associated vasculopathy. RESULTS: ERp72-deficient neutrophils exhibited increased rolling but decreased adhesion/crawling on inflamed venules in vivo and defective static adhesion in vitro. The defect was due to defective activation of integrin Mac-1 but not LFA-1 (lymphocyte function-associated antigen-1) using blocking or epitope-specific antibodies. ERp72 interacted with Mac-1 in lipid rafts on neutrophil surface leading to the reduction of the C654-C711 disulfide bond in the αM subunit that is critical for Mac-1 activation. Recombinant ERp72, via its catalytic motifs, increased the binding affinity of Mac-1 with ICAM-1 (intercellular adhesion molecule-1) and rescued the defective adhesion of ERp72-deficient neutrophils both in vitro and in vivo. Deletion of ERp72 in the bone marrow inhibited neutrophil infiltration, ameliorated tissue damage, and increased survival during murine acute lung injury. CONCLUSIONS: Extracellular ERp72 regulates integrin Mac-1 activity by catalyzing disulfide rearrangement on the αM subunit and may be a novel target for the treatment of neutrophil-associated vasculopathy.


Assuntos
Lesão Pulmonar Aguda , Antígeno de Macrófago 1 , Animais , Camundongos , Lesão Pulmonar Aguda/genética , Lesão Pulmonar Aguda/metabolismo , Adesão Celular , Dissulfetos , Molécula 1 de Adesão Intercelular/metabolismo , Antígeno-1 Associado à Função Linfocitária/metabolismo , Antígeno de Macrófago 1/genética , Antígeno de Macrófago 1/metabolismo , Infiltração de Neutrófilos , Neutrófilos/metabolismo , Compostos de Sulfidrila/metabolismo
2.
J Nanobiotechnology ; 22(1): 363, 2024 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-38910248

RESUMO

Fluorescence nanoscopy, also known as super-resolution microscopy, has transcended the conventional resolution barriers and enabled visualization of biological samples at nanometric resolutions. A series of super-resolution techniques have been developed and applied to investigate the molecular distribution, organization, and interactions in blood cells, as well as the underlying mechanisms of blood-cell-associated diseases. In this review, we provide an overview of various fluorescence nanoscopy technologies, outlining their current development stage and the challenges they are facing in terms of functionality and practicality. We specifically explore how these innovations have propelled forward the analysis of thrombocytes (platelets), erythrocytes (red blood cells) and leukocytes (white blood cells), shedding light on the nanoscale arrangement of subcellular components and molecular interactions. We spotlight novel biomarkers uncovered by fluorescence nanoscopy for disease diagnosis, such as thrombocytopathies, malignancies, and infectious diseases. Furthermore, we discuss the technological hurdles and chart out prospective avenues for future research directions. This review aims to underscore the significant contributions of fluorescence nanoscopy to the field of blood cell analysis and disease diagnosis, poised to revolutionize our approach to exploring, understanding, and managing disease at the molecular level.


Assuntos
Células Sanguíneas , Microscopia de Fluorescência , Animais , Humanos , Células Sanguíneas/ultraestrutura , Plaquetas/metabolismo , Eritrócitos , Hematologia/métodos , Leucócitos/metabolismo , Microscopia de Fluorescência/métodos , Nanotecnologia/métodos
3.
Eur Biophys J ; 51(2): 119-133, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35171346

RESUMO

Mechanobiology is an emerging field at the interface of biology and mechanics, investigating the roles of mechanical forces within biomolecules, organelles, cells, and tissues. As a highlight, the recent advances of micropipette-based aspiration assays and dynamic force spectroscopies such as biomembrane force probe (BFP) provide unprecedented mechanobiological insights with excellent live-cell compatibility. In their classic applications, these assays measure force-dependent ligand-receptor-binding kinetics, protein conformational changes, and cellular mechanical properties such as cortical tension and stiffness. In recent years, when combined with advanced microscopies in high spatial and temporal resolutions, these biomechanical nanotools enable characterization of receptor-mediated cell mechanosensing and subsequent organelle behaviors at single-cellular and molecular level. In this review, we summarize the latest developments of these assays for live-cell mechanobiology studies. We also provide perspectives on their future upgrades with multimodal integration and high-throughput capability.


Assuntos
Fenômenos Mecânicos , Proteínas , Fenômenos Biomecânicos , Biofísica , Cinética , Ligantes , Proteínas/química
4.
Eur Biophys J ; 51(2): 135-146, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35286429

RESUMO

Mechanical stimuli such as tension, compression, and shear stress play critical roles in the physiological functions of red blood cells (RBCs) and their homeostasis, ATP release, and rheological properties. Intracellular calcium (Ca2+) mobilization reflects RBC mechanosensing as they transverse the complex vasculature. Emerging studies have demonstrated the presence of mechanosensitive Ca2+ permeable ion channels and their function has been implicated in the regulation of RBC volume and deformability. However, how these mechanoreceptors trigger Ca2+ influx and subsequent cellular responses are still unclear. Here, we introduce a fluorescence-coupled micropipette aspiration assay to examine RBC mechanosensing at the single-cell level. To achieve a wide range of cell aspirations, we implemented and compared two negative pressure adjusting apparatuses: a homemade water manometer (- 2.94 to 0 mmH2O) and a pneumatic high-speed pressure clamp (- 25 to 0 mmHg). To visualize Ca2+ influx, RBCs were pre-loaded with an intensiometric probe Cal-520 AM, then imaged under a confocal microscope with concurrent bright-field and fluorescent imaging at acquisition rates of 10 frames per second. Remarkably, we observed the related changes in intracellular Ca2+ levels immediately after aspirating individual RBCs in a pressure-dependent manner. The RBC aspirated by the water manometer only displayed 1.1-fold increase in fluorescence intensity, whereas the RBC aspirated by the pneumatic clamp showed up to threefold increase. These results demonstrated the water manometer as a gentle tool for cell manipulation with minimal pre-activation, while the high-speed pneumatic clamp as a much stronger pressure actuator to examine cell mechanosensing directly. Together, this multimodal platform enables us to precisely control aspiration and membrane tension, and subsequently correlate this with intracellular calcium concentration dynamics in a robust and reproducible manner.


Assuntos
Cálcio , Deformação Eritrocítica , Cálcio/metabolismo , Eritrócitos , Canais Iônicos/metabolismo , Transdução de Sinais
5.
Analyst ; 147(6): 1222-1235, 2022 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-35212697

RESUMO

Microvascular thrombosis and inflammation (thromboinflammation) are major causes of morbidity and mortality in critically ill patients with limited therapeutic options. Platelets are central to thromboinflammation, and microvascular platelet thrombi are highly effective at recruiting and activating leukocytes at sites of endothelial injury. Whilst parallel-plate flow chambers, microslides and straight microchannel assays have been widely used to recapitulate leukocyte adhesive behavior on 2-dimensional (2D) surfaces, none of these methods achieve high fidelity 3-dimensional (3D) geometries emulating microvascular platelet thrombi. As a result, the role of hydrodynamic factors in regulating leukocyte interactions with platelet thrombi remains ill-defined. Here, we report a microfluidic post model that allows visualization and analysis of neutrophil-platelet interactions in a 3D flow field. We have utilized the unique mechanosensitive features of platelets to enable selective micropatterning of the 3D posts with human or mouse platelets. By modulating the activation status of platelets, our method enables precise control of platelet surface reactivity and neutrophil recruitment. In addition, our microfluidic post assay accurately recapitulated the rolling versus stationary adhesion behavior of single neutrophils and demonstrated the efficacy of the P-selectin and Mac-1 blocking antibodies to reduce neutrophil recruitment and stationary adhesion, respectively. Moreover, the geometry of posts had a major influence on the efficiency of neutrophil recruitment and adhesion stability. This new post method highlights the importance of platelet 3D geometries in facilitating efficient, localized neutrophil recruitment. These findings have potentially important implications for the potent proinflammatory function of microvascular platelet thrombi.


Assuntos
Plaquetas , Trombose , Animais , Adesão Celular , Humanos , Inflamação , Leucócitos , Camundongos , Microfluídica , Neutrófilos
6.
Phys Chem Chem Phys ; 24(24): 14857-14865, 2022 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-35698887

RESUMO

von Willebrand factor (VWF) senses and responds to the hemodynamic forces to interact with the circulatory system and platelets in hemostasis and thrombosis. The dark side of this mechanobiology is implicated in atherothrombosis, stroke, and, more recently, the COVID-19 thrombotic symptoms. The force-responsive element controlling VWF activation predominantly resides in the N terminal auto-inhibitory module (N-AIM) flanking its A1 domain. Nevertheless, the detailed mechano-chemistry of soluble VWF N-AIM is poorly understood at the sub-molecular level as it is assumed to be unstructured loops. Using the free molecular dynamics (MD) simulations, we first predicted a hairpin-like structure of the soluble A1 N-AIM derived polypeptide (Lp; sequences Q1238-E1260). Then we combined molecular docking and steered molecular dynamics (SMD) simulations to examine how Lp regulates the A1-GPIbα interaction under tensile forces. Our simulation results indicate that Lp suppresses the catch bond in a sandwich complex of A1-Lp-GPIbα yet contributes an additional catch-bond residue D1249. To experimentally benchmark the binding kinetics for A1-GPIbα in the absence or presence of Lp, we conducted the force spectroscopy-biomembrane force probe (BFP) assays. We found similar suppression on the A1-GPIbα catch bond with soluble Lp in presence. Clinically, as more and more therapeutic candidates targeting the A1-GPIbα axis have entered clinical trials to treat patients with TTP and acute coronary syndrome, our work represents an endeavor further towards an effective anti-thrombotic approach without severe bleeding side effects as most existing drugs suffer.


Assuntos
COVID-19 , Complexo Glicoproteico GPIb-IX de Plaquetas/metabolismo , Fator de von Willebrand , Plaquetas , Humanos , Simulação de Acoplamento Molecular , Ligação Proteica , Fator de von Willebrand/química , Fator de von Willebrand/metabolismo
7.
Nano Lett ; 20(7): 4775-4781, 2020 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-32208705

RESUMO

Video-rate super-resolution imaging through biological tissue can visualize and track biomolecule interplays and transportations inside cellular organisms. Structured illumination microscopy allows for wide-field super resolution observation of biological samples but is limited by the strong extinction of light by biological tissues, which restricts the imaging depth and degrades its imaging resolution. Here we report a photon upconversion scheme using lanthanide-doped nanoparticles for wide-field super-resolution imaging through the biological transparent window, featured by near-infrared and low-irradiance nonlinear structured illumination. We demonstrate that the 976 nm excitation and 800 nm upconverted emission can mitigate the aberration. We found that the nonlinear response of upconversion emissions from single nanoparticles can effectively generate the required high spatial frequency components in the Fourier domain. These strategies lead to a new modality in microscopy with a resolution below 131 nm, 1/7th of the excitation wavelength, and an imaging rate of 1 Hz.

8.
Nano Lett ; 20(7): 5133-5140, 2020 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-32530632

RESUMO

Immune checkpoint blockade with monoclonal antibodies (mAbs) that target programmed cell death protein-1 (PD-1) has remarkably revolutionized cancer therapy. Their binding kinetics measured by surface plasmon resonance does not always correlate well with their immunotherapeutic efficacies, mainly due to the lack of two-dimensional cell plasma membrane and the capability of force sensing and manipulation. In this regard, based on a more suitable and ultra-sensitive biomechanical nanotool, biomembrane force probe (BFP), we developed a Double-edge Smart Feedback control system as an ultra-stable platform to characterize ultra-long bond lifetimes of receptor-ligand binding on living cells. We further benchmarked the dissociation kinetics for three clinically approved PD-1 blockade mAbs (Nivolumab, Pembrolizumab, and Camrelizumab), intriguingly correlating well with the objective response rates in the hepatocellular carcinoma second-line treatment. This ultra-stable BFP potentially provides a compelling kinetic platform to direct the screening, optimization, and clinical selection of therapeutic antibodies in the future.


Assuntos
Antineoplásicos Imunológicos , Receptor de Morte Celular Programada 1 , Anticorpos Monoclonais , Antineoplásicos Imunológicos/farmacologia , Cinética , Nivolumabe
9.
Nat Mater ; 18(7): 760-769, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30911119

RESUMO

Integrins are membrane receptors that mediate cell adhesion and mechanosensing. The structure-function relationship of integrins remains incompletely understood, despite the extensive studies carried out because of its importance to basic cell biology and translational medicine. Using a fluorescence dual biomembrane force probe, microfluidics and cone-and-plate rheometry, we applied precisely controlled mechanical stimulations to platelets and identified an intermediate state of integrin αIIbß3 that is characterized by an ectodomain conformation, ligand affinity and bond lifetimes that are all intermediate between the well-known inactive and active states. This intermediate state is induced by ligand engagement of glycoprotein (GP) Ibα via a mechanosignalling pathway and potentiates the outside-in mechanosignalling of αIIbß3 for further transition to the active state during integrin mechanical affinity maturation. Our work reveals distinct αIIbß3 state transitions in response to biomechanical and biochemical stimuli, and identifies a role for the αIIbß3 intermediate state in promoting biomechanical platelet aggregation.


Assuntos
Fenômenos Mecânicos , Agregação Plaquetária , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/metabolismo , Fenômenos Biomecânicos , Humanos , Ligantes , Transdução de Sinais
10.
Bioact Mater ; 42: 328-344, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-39295733

RESUMO

Thrombosis, a leading cause of cardiovascular morbidity and mortality, involves the formation of blood clots within blood vessels. Current animal models and in vitro systems have limitations in recapitulating the complex human vasculature and hemodynamic conditions, limiting the research in understanding the mechanisms of thrombosis. Bioprinting has emerged as a promising approach to construct biomimetic vascular models that closely mimic the structural and mechanical properties of native blood vessels. This review discusses the key considerations for designing bioprinted vascular conduits for thrombosis studies, including the incorporation of key structural, biochemical and mechanical features, the selection of appropriate biomaterials and cell sources, and the challenges and future directions in the field. The advancements in bioprinting techniques, such as multi-material bioprinting and microfluidic integration, have enabled the development of physiologically relevant models of thrombosis. The future of bioprinted models of thrombosis lies in the integration of patient-specific data, real-time monitoring technologies, and advanced microfluidic platforms, paving the way for personalized medicine and targeted interventions. As the field of bioprinting continues to evolve, these advanced vascular models are expected to play an increasingly important role in unraveling the complexities of thrombosis and improving patient outcomes. The continued advancements in bioprinting technologies and the collaboration between researchers from various disciplines hold great promise for revolutionizing the field of thrombosis research.

11.
ACS Nano ; 18(1): 299-313, 2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38105535

RESUMO

Integrins are cell surface nanosized receptors crucial for cell motility and mechanosensing of the extracellular environment, which are often targeted for the development of biomaterials and nanomedicines. As a key feature of integrins, their activity, structure and behavior are highly mechanosensitive, which are regulated by mechanical forces down to pico-Newton scale. Using single-molecule biomechanical approaches, we compared the force-modulated ectodomain bending/unbending conformational changes of two integrin species, α5ß1 and αVß3. It was found that the conformation of integrin α5ß1 is determined by a threshold head-to-tail tension. By comparison, integrin αVß3 exhibits bistability even without force and can spontaneously transition between the bent and extended conformations with an apparent transition time under a wide range of forces. Molecular dynamics simulations observed almost concurrent disruption of ∼2 hydrogen bonds during integrin α5ß1 unbending, but consecutive disruption of ∼7 hydrogen bonds during integrin αVß3 unbending. Accordingly, we constructed a canonical energy landscape for integrin α5ß1 with a single energy well that traps the integrin in the bent state until sufficient force tilts the energy landscape to allow the conformational transition. In contrast, the energy landscape of integrin αVß3 conformational changes was constructed with hexa-stable intermediate states and intermediate energy barriers that segregate the conformational change process into multiple small steps. Our study elucidates the different biomechanical inner workings of integrins α5ß1 and αVß3 at the submolecular level, helps understand their mechanosignaling processes and how their respective functions are facilitated by their distinctive mechanosensitivities, and provides useful design principles for the engineering of protein-based biomechanical nanomachines.


Assuntos
Integrina alfa5beta1 , Integrinas , Integrina alfa5beta1/metabolismo , Integrinas/metabolismo , Simulação de Dinâmica Molecular , Integrina alfaVbeta3/metabolismo
12.
J Vis Exp ; (203)2024 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-38284529

RESUMO

Micropipette aspiration assays have long been a cornerstone for the investigation of live-cell mechanics, offering insights into cellular responses to mechanical stress. This paper details an innovative adaptation of the fluorescence-coupled micropipette aspiration (fMPA) assay. The fMPA assay introduces the capability to administer precise mechanical forces while concurrently monitoring the live-cell mechanotransduction processes mediated by ion channels. The sophisticated setup incorporates a precision-engineered borosilicate glass micropipette connected to a finely regulated water reservoir and pneumatic aspiration system, facilitating controlled pressure application with increments as refined as ± 1 mmHg. A significant enhancement is the integration of epi-fluorescence imaging, allowing for the simultaneous observation and quantification of cell morphological changes and intracellular calcium fluxes during aspiration. The fMPA assay, through its synergistic combination of epi-fluorescence imaging with micropipette aspiration, sets a new standard for the study of cell mechanosensing within mechanically challenging environments. This multifaceted approach is adaptable to various experimental setups, providing critical insights into the single-cell mechanosensing mechanisms.


Assuntos
Eritrócitos , Mecanotransdução Celular , Mecanotransdução Celular/fisiologia , Fluorescência , Estresse Mecânico , Pressão
13.
Adv Sci (Weinh) ; 11(30): e2401524, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38757670

RESUMO

Use of extracorporeal membrane oxygenation (ECMO) for cardiorespiratory failure remains complicated by blood clot formation (thrombosis), triggered by biomaterial surfaces and flow conditions. Thrombosis may result in ECMO circuit changes, cause red blood cell hemolysis, and thromboembolic events. Medical device thrombosis is potentiated by the interplay between biomaterial properties, hemodynamic flow conditions and patient pathology, however, the contribution and importance of these factors are poorly understood because many in vitro models lack the capability to customize material and flow conditions to investigate thrombosis under clinically relevant medical device conditions. Therefore, an ECMO thrombosis-on-a-chip model is developed that enables highly customizable biomaterial and flow combinations to evaluate ECMO thrombosis in real-time with low blood volume. It is observed that low flow rates, decelerating conditions, and flow stasis significantly increased platelet adhesion, correlating with clinical thrombus formation. For the first time, it is found that tubing material, polyvinyl chloride, caused increased platelet P-selectin activation compared to connector material, polycarbonate. This ECMO thrombosis-on-a-chip model can be used to guide ECMO operation, inform medical device design, investigate embolism, occlusion and platelet activation mechanisms, and develop anti-thrombotic biomaterials to ultimately reduce medical device thrombosis, anti-thrombotic drug use and therefore bleeding complications, leading to safer blood-contacting medical devices.


Assuntos
Oxigenação por Membrana Extracorpórea , Dispositivos Lab-On-A-Chip , Ativação Plaquetária , Adesividade Plaquetária , Trombose , Oxigenação por Membrana Extracorpórea/métodos , Oxigenação por Membrana Extracorpórea/instrumentação , Trombose/etiologia , Humanos , Ativação Plaquetária/fisiologia , Plaquetas/metabolismo
14.
Nat Commun ; 15(1): 5521, 2024 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-38951553

RESUMO

The microgeometry of the cellular microenvironment profoundly impacts cellular behaviors, yet the link between it and the ubiquitously expressed mechanosensitive ion channel PIEZO1 remains unclear. Herein, we describe a fluorescent micropipette aspiration assay that allows for simultaneous visualization of intracellular calcium dynamics and cytoskeletal architecture in real-time, under varied micropipette geometries. By integrating elastic shell finite element analysis with fluorescent lifetime imaging microscopy and employing PIEZO1-specific transgenic red blood cells and HEK cell lines, we demonstrate a direct correlation between the microscale geometry of aspiration and PIEZO1-mediated calcium signaling. We reveal that increased micropipette tip angles and physical constrictions lead to a significant reorganization of F-actin, accumulation at the aspirated cell neck, and subsequently amplify the tension stress at the dome of the cell to induce more PIEZO1's activity. Disruption of the F-actin network or inhibition of its mobility leads to a notable decline in PIEZO1 mediated calcium influx, underscoring its critical role in cellular mechanosensing amidst geometrical constraints.


Assuntos
Actinas , Cálcio , Citoesqueleto , Canais Iônicos , Mecanotransdução Celular , Humanos , Canais Iônicos/metabolismo , Actinas/metabolismo , Células HEK293 , Citoesqueleto/metabolismo , Cálcio/metabolismo , Sinalização do Cálcio/fisiologia , Análise de Elementos Finitos , Animais , Microscopia de Fluorescência/métodos
15.
Nat Commun ; 15(1): 9067, 2024 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-39433750

RESUMO

Arterial thrombosis is a leading cause of death and disability worldwide with no effective bioassay for clinical prediction. As a symbolic feature of arterial thrombosis, severe stenosis in the blood vessel creates a high-shear, high-gradient flow environment that facilitates platelet aggregation towards vessel occlusion. Here, we present a thrombus profiling assay that monitors the multi-dimensional attributes of thrombi forming in such biomechanical conditions. Using this assay, we demonstrate that different receptor-ligand interactions contribute distinctively to the composition and activation status of the thrombus. Our investigation into hypertensive and older individuals reveals intensified biomechanical thrombogenesis and multi-dimensional thrombus profile abnormalities, endorsing the diagnostic potential of the assay. Furthermore, we identify the hyperactivity of GPIbα-integrin αIIbß3 mechanosensing axis as a molecular mechanism that contributes to hypertension-associated arterial thrombosis. By studying drug-disease interactions and inter-individual variability, our work reveals a need for personalized anti-thrombotic drug selection that accommodates each patient's pathological profile.


Assuntos
Envelhecimento , Hipertensão , Trombose , Humanos , Trombose/metabolismo , Hipertensão/fisiopatologia , Masculino , Idoso , Feminino , Pessoa de Meia-Idade , Microfluídica/métodos , Agregação Plaquetária , Complexo Glicoproteico GPIb-IX de Plaquetas/metabolismo , Fenômenos Biomecânicos , Adulto , Plaquetas/metabolismo
16.
bioRxiv ; 2024 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-38915705

RESUMO

Arterial thrombosis, which represents a critical complication of cardiovascular diseases, is a leading cause of death and disability worldwide with no effective bioassay for clinical prediction. As a symbolic feature of arterial thrombosis, severe stenosis in the blood vessel creates a high-shear, high-gradient flow environment that effectively facilitates platelet aggregation towards vessel occlusion even with platelet amplification loops inhibited. However, no approach is currently available to comprehensively characterize the size, composition and platelet activation status of thrombi forming under this biorheological condition. Here, we present a thrombus profiling assay that monitors the multi-dimensional attributes of thrombi forming in conditions mimicking the physiological scenario of arterial thrombosis. Using this platform, we demonstrate that different receptor-ligand interactions contribute distinctively to the composition and activation status of the thrombus. Our investigation into hypertensive and older individuals reveals intensified biomechanical thrombogenesis and multi-dimensional thrombus profile abnormalities, demonstrating a direct contribution of mechanobiology to arterial thrombosis and endorsing the diagnostic potential of the assay. Furthermore, we identify the hyperactivity of GPIbα-integrin αIIbß3 mechanosensing axis as a molecular mechanism that contributes to hypertension-associated arterial thrombosis. By studying the interactions between anti-thrombotic inhibitors and hypertension, and the inter-individual variability in personal thrombus profiles, our work reveals a critical need for personalized anti-thrombotic drug selection that accommodates each patient's pathological profile.

17.
Cell Rep Methods ; 3(7): 100536, 2023 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-37533648

RESUMO

Li and colleagues have made a notable advancement in predicting cancer-associated thrombosis with a microfluidic device that monitors circulating platelet activity.1 This tool could improve the management of thrombotic events in patients with cancer, guiding timely treatment and potentially reducing mortality.


Assuntos
Neoplasias , Trombose , Humanos , Plaquetas , Microfluídica , Neoplasias/complicações , Trombose/diagnóstico , Trombose/etiologia
18.
Biosensors (Basel) ; 13(1)2023 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-36671930

RESUMO

Cancer cells interacting with the extracellular matrix (ECM) in the tumor microenvironment is pivotal for tumorigenesis, invasion, and metastasis. Cell-ECM adhesion has been intensively studied in cancer biology in the past decades to understand the molecular mechanisms underlying the adhesion events and extracellular mechanosensing, as well as develop therapeutic strategies targeting the cell adhesion molecules. Many methods have been established to measure the cell-ECM adhesion strength and correlate it with the metastatic potential of certain cancer types. However, those approaches are either low throughput, not quantitative, or with poor sensitivity and reproducibility. Herein, we developed a novel acoustic force spectroscopy based method to quantify the cell-ECM adhesion strength during adhesion maturation process using the emerging z-Movi® technology. This can be served as a fast, simple, and high-throughput platform for functional assessment of cell adhesion molecules in a highly predictive and reproducible manner.


Assuntos
Neoplasias , Humanos , Adesão Celular/fisiologia , Reprodutibilidade dos Testes , Neoplasias/patologia , Matriz Extracelular/metabolismo , Matriz Extracelular/patologia , Fenômenos Mecânicos , Microambiente Tumoral/fisiologia
19.
bioRxiv ; 2023 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-36712101

RESUMO

Force can modulate the properties and functions of macromolecules by inducing conformational changes, such as coiling/uncoiling, zipping/unzipping, and folding/unfolding. Here we compared force-modulated bending/unbending of two purified integrin ectodomains, α 5 ß 1 and α V ß 3 , using single-molecule approaches. Similar to previously characterized mechano-sensitive macromolecules, the conformation of α 5 ß 1 is determined by a threshold head-to-tail tension, suggesting a canonical energy landscape with a deep energy well that traps the integrin in the bent state until sufficient force tilts the energy landscape to accelerate transition to the extended state. By comparison, α V ß 3 exhibits bi-stability even without force and can spontaneously transition between the bent and extended conformations in a wide range of forces without energy supplies. Molecular dynamics simulations revealed consecutive formation and disruption of 7 hydrogen bonds during α V ß 3 bending and unbending, respectively. Accordingly, we constructed an energy landscape with hexa-stable intermediate states to break down the energy barrier separating the bent and extended states into smaller ones, making it possible for the thermal agitation energy to overcome them sequentially and to be accumulated and converted into mechanical work required for α V ß 3 to bend against force. Our study elucidates the different inner workings of α 5 ß 1 and α V ß 3 at the sub-molecular level, sheds lights on how their respectively functions are facilitated by their distinctive mechano-sensitivities, helps understand their signal initiation processes, and provides critical concepts and useful design principles for engineering of protein-based biomechanical nanomachines.

20.
Exploration (Beijing) ; 3(4): 20230004, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37933233

RESUMO

Mechanical forces play a vital role in biological processes at molecular and cellular levels, significantly impacting various diseases such as cancer, cardiovascular disease, and COVID-19. Recent advancements in dynamic force spectroscopy (DFS) techniques have enabled the application and measurement of forces and displacements with high resolutions, providing crucial insights into the mechanical pathways underlying these diseases. Among DFS techniques, the biomembrane force probe (BFP) stands out for its ability to measure bond kinetics and cellular mechanosensing with pico-newton and nano-meter resolutions. Here, a comprehensive overview of the classical BFP-DFS setup is presented and key advancements are emphasized, including the development of dual biomembrane force probe (dBFP) and fluorescence biomembrane force probe (fBFP). BFP-DFS allows us to investigate dynamic bond behaviors on living cells and significantly enhances the understanding of specific ligand-receptor axes mediated cell mechanosensing. The contributions of BFP-DFS to the fields of cancer biology, thrombosis, and inflammation are delved into, exploring its potential to elucidate novel therapeutic discoveries. Furthermore, future BFP upgrades aimed at improving output and feasibility are anticipated, emphasizing its growing importance in the field of cell mechanobiology. Although BFP-DFS remains a niche research modality, its impact on the expanding field of cell mechanobiology is immense.

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