Publications by authors named "MingJun Cai"

Exosomes are small endosome-derived extracellular vesicles that participate in cell-cell communication, particularly in the context of tumorigenesis, and their secretion is influenced by the tumor microenvironment. While previous studies suggest that mechanical forces may enhance exosome release, the direct relationship between these forces and exosome secretion needs to be further characterized. Here, we utilized dual-color CD63 reporter-based high-speed live-cell imaging to visualize how mechanical forces influence exosome release in situ.

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Environmental mechanical forces, such as cell membrane stress, cell extrusion, and stretch, have been proven to affect cell growth and migration. Piezo1, a mechanosensitive channel protein, responds directly to endogenous or exogenous mechanical stimuli. Here, we explored the Piezo1 distribution and microfilament morphological changes induced by mechanical forces in the tumor and normal cells.

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The weakness of the fiber-matrix interface restricts the practical application of basalt fiber (BF) as a reinforcing material. In order to improve the interfacial adhesion between the BF and epoxy matrix, surface activation of the BF was carried out using low-pressure O and H-Ar plasma under various conditions. The interfacial shear strength (IFSS), evaluated by a micro-droplet de-bonding test, was adopted to demonstrate the bonding effects at the BF/epoxy interphase.

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N6-methyladenosine (m6A) is the most common and prevalent internal mRNA modification in eukaryotes. m6A modification is a dynamic and reversible process regulated by methyltransferases, demethylases, and m6A binding proteins. Skin cancers, including melanoma and nonmelanoma skin cancers (NMSCs), are among the most commonly diagnosed cancers worldwide.

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Objective: To investigate the significance of endoscopic grading (Hill's classification) of gastroesophageal flap valve (GEFV) in the examination of patients with gastroesophageal reflux disease (GERD).

Methods: One hundred and sixty-two patients undergoing gastroscopy in the Department of Gastroenterology, Xingyi People's Hospital between Apr. 2022 and Sept.

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This study compares the accuracy and safety of pedicle screw placement using a 3D navigation template with the free-hand fluoroscopy technique in scoliotic patients. Fifteen scoliotic patients were recruited and divided into a template group (eight cases) and a free-hand group (seven cases). All patients received posterior corrective surgeries, and the pedicle screw was placed using a 3D navigation template or a free-hand technique.

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A major role of cell membranes is to provide an ideal environment for the constituent proteins to perform their biological functions. A deep understanding of the membrane proteins assembly process under physiological conditions is quite important to elucidate both the structure and the function of the cell membranes. Along these lines, in this work, a complete workflow of the cell membrane sample preparation and the correlated AFM and dSTORM imaging analysis methods are presented.

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CDCP1 is a transmembrane protein that is involved in a variety of important biological processes and upregulated in a variety of human solid malignancies; however, its spatial distribution and variation at the molecular level remain unclear. To solve this problem, we first analyzed its expression level and prognostic implications in lung cancer. Then, we used super-resolution microscopy to reveal the spatial organization of CDCP1 at different levels, and found that cancer cells generated more and larger CDCP1 clusters than normal cells.

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Article Synopsis
  • The glucagon receptor (GCGR) is part of the G protein-coupled receptor family, and its response to glucagon in high glucose conditions is not well understood.
  • Research using advanced imaging techniques showed that high glucose increases GCGR expression and creates larger clusters on cell membranes.
  • The study also found that high glucose leads to glucagon resistance, especially in cancerous liver cells, which could have implications for understanding diabetes and drug development targeting GCGR.
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Most plasmalemmal proteins are organized into clusters to modulate various cellular functions. However, the machineries that regulate protein clustering remain largely unclear. Here, with EGFR as an example, we directly and in detail visualized the entire process of EGFR from synthesis to secretion onto the plasma membrane (PM) using a high-speed, high-resolution spinning-disk confocal microscope.

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Impaired insulin release is the key feature of type 2 diabetes. Insulin secretion, mainly mediated by SNARE proteins, is closely related to the blood glucose level. However, the mechanism underlying how glucose controls SNARE proteins to regulate insulin release is largely unexplained.

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Cells can regulate a variety of behaviors by sensing mechanical signals, including growth, differentiation, apoptosis and so on. Yes-associated protein (YAP) is a mechanically sensitive protein that can be used as an indicator of mechanosignaling transduction. Unlike macroscopic statistical analysis, single-cell analysis is more demanding and challenging in terms of mechanistic regulation.

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The popularity of RNA nanoparticles (RNPs) has risen rapidly during the past decade due to the development of RNA nanotechnology. Understanding the fast dynamic process of cell entry and intracellular delivery of RNPs is essential for the design of intelligent therapeutic RNA nano-drugs and mRNA vaccines.How the interaction between the membrane and target ligand of RNPs influences the cell entry, and how the dynamic mechanism of RNPs takes place in different organelles remain ill-defined.

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Insulin receptor (INSR) is a key protein in the INSR signaling pathway and plays a critical role in biological processes, especially in the regulation of glucose homeostasis. Many metabolic diseases are often accompanied by abnormal INSR signaling. However, the specific effector mechanisms regulating insulin resistance and the distribution patterns of INSR during cell membrane activation remain unclear.

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CUB domain-containing protein 1 (CDCP1), as an emerging transmembrane protein, is overexpressed in a variety of malignant tumors including respiratory tumors, digestive system cancers, hematological malignancies and urogenital cancers. Several cancer-related proteins have been reported to interact with CDCP1. It acts as a crucial hub in multiple classical signaling pathways of tumorigenesis and progression.

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Endocytosis, as one of the main ways for nanostructures enter cells, is affected by several aspects, and shape is an especially critical aspect during the endocytosis of nanostructures. However, it has remained challenging to capture the dynamic internalization behaviors of rod-shaped nanostructures while also probing the mechanical aspects of the internalization. Here, using the atomic force microscopy-based force tracing technique, transmission electron microscopy, and molecular dynamic simulation, we mapped the detailed internalization behaviors of rod-shaped nanostructures with different aspect ratios at the single-particle level.

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Human epidermal growth factor receptor-2 (HER2) is a member of the epidermal growth factor receptor (HER) family that is involved in various biological processes such as cell proliferation, survival, differentiation, migration and invasion. It generally functions in the form of homo-/hetero-dimers or oligomers with other HER family members. Although its essential roles in cellular activities have been widely recognized, questions concerning the spatial distribution of HER2 on the membranes and the interactions between it and other ErbB family members remain obscure.

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Membrane proteins tend to interact with each other in the cell membranes to form protein clusters and perform the corresponding physiological functions. However, because channel proteins are involved in many biological functions, their distribution and nano-organization in these protein clusters are unclear. To study the distribution patterns and relationships between the different channel proteins, we identified the locations of glucose transporter 1 (Glut1) and Band3 (anion transporter 1) precisely in the topography of the cytoplasmic side of the human red blood cell (hRBC) membranes using combined atomic force microscopy (AFM) and single-molecule localization microscopy (SMLM).

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Electromechanical interaction of cells and extracellular matrix are ubiquitous in biological systems. Understanding the fundamentals of this interaction and feedback is critical to design next-generation electroactive tissue engineering scaffold. Herein, based on elaborately modulating the dynamic mechanical forces in cell microenvironment, the design of a smart piezoelectric scaffold with suitable stiffness analogous to that of collagen for on-demand electrical stimulation is reported.

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Membrane fusion is fundamental to biological activity of cells, so disclosingits relevant mechanism is very important for understanding various cell functions. Although artificial model systems have been developed to uncover the mechanism of membrane fusion, key factors determining the mode of membrane fusion remain unclear. Based on the construction of different types of liposome vesicles, we used a dynamic fluorescence imaging method to investigate the effect of membrane protein distribution density on membrane fusion.

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As a transmembrane protein, CD47 plays an important role in mediating cell proliferation, migration, phagocytosis, apoptosis, immune homeostasis, inhibition of NO signal transduction and other related reactions. Upon the interaction of innate immune checkpoint CD47-SIRPα occurrence, they send a "don't eat me" signal to the macrophages. This signal ultimately helps tumors achieve immune escape by inhibiting macrophage contraction to prevent tumor cells from phagocytosis.

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The transmembrane glycoprotein Trop2 plays important roles in various types of human cancers, especially lung cancer. Although it has been found to form clusters on cancer cell membranes, the factors that affect its clustering are not yet fully understood. Here, using direct stochastic optical reconstruction microscopy (dSTORM), we found that Trop2 generated more, larger, and denser clusters on apical cell membranes than on basal membranes and that the differences might be related to the different membrane structures.

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Article Synopsis
  • Small fluorescent probes, made from single-targeted small-molecule inhibitors (SMIs), are essential for high-resolution super-resolution fluorescence microscopy.
  • The study modified the tyrosine kinase inhibitor Gefitinib to create a fluorescent probe called Gefitinib-probe, which was shown to specifically label the EGF receptor (EGFR).
  • Results revealed that the Gefitinib-probe provided superior labeling and dual-color imaging capabilities compared to traditional antibody-probe pairs, demonstrating its potential as a versatile tool for advanced imaging techniques.
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Relying on an inhibitor-based probe, we reveal the clustered distribution of membrane PSMA by dSTORM imaging and uncover its potential interaction with folate receptor. This inhibitor-based strategy realizes more accurate labeling than antibody labeling, which would make it a powerful tool in the field of dSTORM imaging.

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