Vaccinia virus (VACV)-induced cell migration is thought to be closely related to the rapid transmission of viral infection in the body. The limited studies are mainly based on scratch assay using traditional cell culture techniques, which inevitably ignores the influences of extracellular microenvironment. Physical confinement, inherently presenting in vivo, has proven to be a critical extern cue in modulating migration behaviors of multiple cells, while its impacts on VACV-induced cell motility remain unclear. Herein, we developed a migration assay microchip featuring confined microchannel array to investigate the effect of physical confinement on infected cell morphology and motility during VACV infection. Results showed that different from the random cell migration observed in traditional scratch assay on planar substrate, VACV-infected cells exhibited accelerated directionally persistent migration under confinement microenvironment. Moreover, single-directed elongated dominant lamella appeared to contrast distinctly with multiple protrusions stretched in random directions under unconfined condition. Additionally, the Golgi complex tended to relocate behind the nucleus confined within the microchannel axis compared to the classical reorientation pattern. These differences in characteristic subcellular architecture and organelle reorientation of migrating cells revealed cell biological mechanisms underlying altered migration behavior. Collectively, our study demonstrates that physical confinement acting as a guidance cue has profound impacts on VACV-induced migration behaviors, which provides new insight into cell migration behavior and viral rapid spread during VACV infection.

Developing more effective bioactive ingredients of natural origin is imperative for promoting wound healing. Sea cucumbers have long enjoyed a good reputation as both food delicacies and traditional medicines. In this study, we heterogeneously expressed a Apostichopus japonicus derived novel protein AjPSPLP-3, which exhibits a theoretical molecular weight of 13.034 kDa, through fusion with maltose binding protein (MBP). AjPSPLP-3 contains a strict CXXCXC motif, nine extremely conserved cysteine residues and two highly conserved cysteine residues. The predicted structure of AjPSPLP-3 consists of random coil and nine β-sheets, Cys30-Cys67, Cys38-Cys58, Cys53-Cys90, Cys56-Cys66, and Cys81-Cys102 participating in the formation of five pairs of disulfide bonds. In vitro experiments conducted on HaCaT cells proved that AjPSPLP-3 and MBP-fused AjPSPLP-3 significantly contribute to HaCaT cells proliferation and migration without exhibiting hemolytic activity on murine erythrocytes. Specifically, treatment with 10 μmol/L MBP-fused AjPSPLP-3 protein increased the viability of HaCaT cells by 12.28 % (p < 0.001), while treatment with 10 μmol/L AjPSPLP-3 protein increased viability of HaCaT cells by 6.01 % (p < 0.01). Furthermore, wound closure of MBP-fused AjPSPLP-3 and AjPSPLP-3 were 22.51 % (p < 0.01) and 7.32 % (p < 0.05) higher than that of the control groups in HaCaT cells following 24 h of incubation.

Skeletal muscle fibrosis is defined as the excessive accumulation of extracellular matrix (ECM) components and is a hallmark of muscular dystrophies. Fibro-adipogenic progenitors (FAPs) are the main source of ECM, and thus have been strongly implicated in fibrogenesis. In skeletal muscle fibrotic models, including muscular dystrophies, FAPs undergo dysregulations in terms of proliferation, differentiation, and apoptosis, however few studies have explored the impact of FAPs migration. Here, we studied fibroblast and FAPs migration and identified lysophosphatidic acid (LPA), a signaling lipid central to skeletal muscle fibrogenesis, as a significant migration inductor. We identified LPA receptor 1 (LPA1) mediated signaling as crucial for this effect through a mechanism dependent on the Hippo pathway, another pathway implicated in fibrosis across diverse tissues. This cross-talk favors the activation of the Yes-associated protein 1 (YAP) and Transcriptional coactivator with PDZ-binding motif (TAZ), leading to increased expression of fibrosis-associated genes. This study reveals the role of YAP in LPA-mediated fibrotic responses as inhibition of YAP transcriptional coactivator activity hinders LPA-induced migration in fibroblasts and FAPs. Moreover, we found that FAPs derived from the mdx4cv mice, a murine model of Duchenne muscular dystrophy, display a heightened migratory phenotype due to enhanced LPA signaling compared to wild-type FAPs. Remarkably, we found that the inhibition of LPA1 or YAP transcriptional coactivator activity in mdx4cv FAPs reverts this phenotype. In summary, the identified LPA-LPA1-YAP pathway emerges as a critical driver of skeletal muscle FAPs migration and provides insights into potential novel targets to mitigate fibrosis in muscular dystrophies.

BACKGROUND: The scratch assay is commonly used in cell biology to evaluate cell migration; however, it is not a standardized method; it produces highly variable gap dimensions. We design a printable device, comprising a single wounding tool and a guide, and compared the gap produced by our device and the traditional method. The deviceis printable in a standard 3D printer. Cells were seeded on a 24-well plate. After reaching full confluency, a gap was created using the traditional method (scratch assay with a pipette tip), a pipette tip and the guide of the device, or the single wounding tool and the guide. The gaps were observed for up to 48 h under a light microscope and analyzed.
RESULTS: The results show that the traditional method produces irregular and not straight gaps, and had the worst cell migration rates compared to the other groups. The wounding tool produced scrape signs at the well surface.
CONCLUSIONS: The guide and pipette tip delivered the best results for the scratch assay.
CONCLUSIONS: The use of the guide and the pipette tip for the scratch assay allows allows to perform reproducible cell migration experiments.

Amoeboid cell motility is fundamental for a multitude of biological processes such as embryogenesis, immune responses, wound healing, and cancer metastasis. It is characterized by specific cell shape changes: the extension and retraction of membrane protrusions, known as pseudopodia. A common approach to investigate the mechanisms underlying this type of cell motility is to study phenotypic differences in the locomotion of mutant cell lines. To characterize such differences, methods are required to quantify the contour dynamics of migrating cells. AmoePy is a Python-based software package that provides tools for cell segmentation, contour detection as well as analyzing and simulating contour dynamics. First, a digital representation of the cell contour as a chain of nodes is extracted from each frame of a time-lapse microscopy recording of a moving cell. Then, the dynamics of these nodes-referred to as virtual markers-are tracked as the cell contour evolves over time. From these data, various quantities can be calculated that characterize the contour dynamics, such as the displacement of the virtual markers or the local stretching rate of the marker chain. Their dynamics is typically visualized in space-time plots, the so-called kymographs, where the temporal evolution is displayed for the different locations along the cell contour. Using AmoePy, you can straightforwardly create kymograph plots and videos from stacks of experimental bright-field or fluorescent images of motile cells. A hands-on guide on how to install and use AmoePy is provided in this chapter.

Immune responses rely on efficient and coordinated migration of immune cells to the site of infection or injury. To reach the site of immunological threat often requires long-range navigation of immune cells through complex tissue and vascular networks. Chemotaxis, cell migration steered by gradients of cell-attractive chemicals that bind sensory receptors, is central to this response. Chemoattractant receptors mostly belong to the G-protein-coupled receptor (GPCR) family, but the way attractant-receptor signaling directs cell migration is not fully understood. Direct-viewing chemotaxis chambers combined with time-lapse microscopy give a powerful tool to study the dynamic details of cells\' responses to different attractant landscapes. Here, we describe the application of one such chamber (the Dunn chamber) to study bone marrow-derived macrophage chemotaxis to gradients of complement C5a.

UNASSIGNED: Aminoacylase 1 (ACY-1) has been found to be a tumor suppressor gene in neuroblastoma (NB). This study aimed to identify and verify the microRNAs (miRNAs) that may regulate ACY-1 through database prediction analysis, and verify the mutual regulatory effect of miRNA and ACY-1 in NB through cell experiments.
UNASSIGNED: The miRNAs that might bind ACY-1 were predicted and selected by TargetScan, miRTarBase and four other databases, the expression of the predicted miRNAs and ACY-1 was detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) in four groups of clinical samples, and the differentially expressed miRNAs were screened. Then, luciferase vector was constructed according to the ACY-1 gene sequence to detect whether ACY-1 binds to the selected miRNA. Then, miR-1271-5p expression was silenced to detect miR-1271-5p function in the growth and migration of NB. Finally, ACY-1 and miR-1271-5p were silenced to change ACY-1 expression, and ACY-1 function in NB and the regulatory role of miR-1271-5p were explored.
UNASSIGNED: ACY-1 was downregulated in NB, miR-1271-5p was upregulated in NB, and miR-1271-5p could be targeted to ACY-1. Silencing miR-1271-5p expression can reduce cell viability and inhibit tumor progression. After interfering with ACY-1 expression in cells, cell viability was enhanced, apoptosis was significantly decreased, and migration and invasion were enhanced. After partially restoring ACY-1 expression, the effect of si-ACY-1 on cells was weakened. In SK-N-SH and SH-SY-5Y cells, the miR-1271-5p inhibitor restored ACY-1 expression and improved ACY-1 function.
UNASSIGNED: MiR-1271-5p can promote the growth and migration of tumor cells by inhibiting ACY-1 expression in NB.

The migration of breast cancer cells is the main cause of death and significantly regulated by physical factors of the extracellular matrix (ECM). To be specific, the curvature and stiffness of the ECM were discovered to effectively guide cell migration in velocity and direction. However, it is not clear what the extent of effect is when these dual-physical factors regulate cell migration. Moreover, the mechanobiology mechanism of breast cancer cell migration in the molecular level and analysis of cell traction force (CTF) are also important, but there is a lack of systematic investigation. Therefore, we employed a microfluidic platform to construct hydrogel microspheres with an independently adjustable curvature and stiffness as a three-dimensional substrate for breast cancer cell migration. We found that the cell migration velocity was negatively correlated to curvature and positively correlated to stiffness. In addition, curvature was investigated to influence the focal adhesion expression as well as the assignment of F-actin at the molecular level. Further, with the help of a motor-clutch mathematical model and hydrogel microsphere stress sensors, it was concluded that cells perceived physical factors (curvature and stiffness) to cause changes in CTF, which ultimately regulated cell motility. In summary, we employed a theoretical model (motor-clutch) and experimental strategy (stress sensors) to understand the mechanism of curvature and stiffness regulating breast cancer cell motility. These results provide evidence of force driven cancer cell migration by ECM physical factors and explain the mechanism from the perspective of mechanobiology.

Deep vein thrombosis (DVT) is a common postoperative complication of orthopaedic surgery with a complex pathogenesis mechanism. The effect of the miR-2467-3p/acting-binding LIM protein 1 (ABLIM1) axis on thrombus formation and human vascular endothelial cells (HUVECs) progression was evaluated aiming to identify a novel potential biomarker of DVT. DVT rat models were established by inferior vena cava stenosis. The expression of the miR-2467-3p/ABLIM1 axis was analyzed by PCR. HUVECs were induced with oxidative low-density lipoprotein (ox-LDL). Cell growth and motility were assessed by cell counting kit 8 (CCK8) and Transwell assay. The inflammation and oxidative stress were estimated by proinflammatory cytokines and generation of MDA and reactive oxygen species (ROS). ABLIM1 was downregulated in DVT rats. Overexpressing ABLIM1 could suppress the formation of thrombosis and alleviate inflammation and oxidative stress. In HUVECs, ox-LDL induced significantly increased miR-2467-3p and decreased ABLIM1, and miR-2467-3p could negatively regulate ABLIM1. The knockdown of miR-2467-3p could alleviate the inhibited cell growth and motility by ox-LDL, and the inflammation and oxidative stress were also attenuated. While silencing could reverse the effect of miR-2467-3p on ox-LDL-induced HUVECs. The miR-2467-3p/ABLIM1 axis regulates the occurrence and development of DVT through modulating HUVECs inflammation and oxidative stress.

The ubiquitin-proteasome system (UPS), which involves E3 ligases and deubiquitinases (DUBs), is critical for protein homeostasis. The epigenetic reader ZMYND8 (zinc finger MYND-type containing 8) has emerged as an oncoprotein, and its protein levels are elevated in various types of cancer, including breast cancer. However, the mechanism by which ZMYND8 protein levels are increased in cancer remains elusive. Although ZMYND8 has been reported to be regulated by the E3 ligase FBXW7, it is still unknown whether ZMYND8 could be modulated by DUBs. Here, we identified USP7 (ubiquitin carboxyl-terminal hydrolase 7) as a bona fide DUB for ZMYND8. Mechanically, USP7 directly binds to the PBP (PHD-BRD-PWWP) domain of ZMYND8 via its TRAF (tumor necrosis factor receptor-associated factor) domain and UBL (ubiquitin-like) domain and removes F-box and WD repeat domain containing 7 (FBXW7)-catalyzed poly-ubiquitin chains on lysine residue 1034 (K1034) within ZMYND8, thereby stabilizing ZMYND8 and stimulating the transcription of ZMYND8 target genes ZEB1 (zinc finger E-box binding homeobox 1) and VEGFA (Vascular Endothelial Growth Factor A). Consequently, USP7 enhances the capacity of breast cancer cells for migration and invasion through antagonizing FBXW7-mediated ZMYND8 degradation. Importantly, the protein levels of USP7 positively correlates with those of ZMYND8 in breast cancer tissues. These findings delineate an important layer of migration and invasion regulation by the USP7-ZMYND8 axis in breast cancer cells.