Regulation Of Cell-cell Adhesion Research Articles

Prognostic value of GARS in bladder cancer and its role in the tumor microenvironment.

Bladder cancer (BC), as a common type of cancer, has a poor prognosis, also some common invasive prognostic or therapeutic markers are difficult to obtain, which makes further treatment of BC difficult. Glycyl-tRNA synthetase (GARS), as one of the aminoacyl-tRNA synthetases that charge tRNAs with their cognate amino acids, has been identified as a target in many diseases, including tumors. Bioassay analysis revealed that GARS was in high expression in most cancer tissues. The expression of GARS gene in BC tissues could assess the prognosis of BC patients, and the expression in urinary extracellular vesicles (uEVs) of patients was positively correlated with the expression in tissues. In addition to this, we analyzed GARS-related differential gene expression, copy number variation (CNV) and mutation profiles, potential biological functions, immune cell infiltration and drug sensitivity. In vivo and vitro tumorigenic experiments were performed to validate the function of GARS. Single-cell data were used to further analyze its role in the microenvironment. In our study, we found that GARS was highly expressed in 30 cancer tissues including BC, and high GARS expression was negatively correlated with the prognosis of BC patients. To address this phenomenon, we analyzed the differential genes between high and low GARS groups by enrichment analysis, and identified the biological signaling pathways that were mainly enriched for their functions, and found that the enrichment was found in immune-related signaling pathways and regulation of cell-cell adhesion. Then we found that GARS was positively associated with immune cell infiltration in BC, and some common immune checkpoints were significantly overexpressed in the GARS-high group. Besides, we found that GARS was enriched in myofibroblasts in the tumor microenvironment, and the enrichment was positively correlated with epithelial-mesenchymal transition (EMT)-related genes. This study also showed a positive correlation between GARS and BC RNA stemness. Patients in the GARS-high group had considerably higher rates of P53 and Titin (TTN) mutations than those in the GARS-low group. Drug Sensitivity analysis screened for drugs that were more sensitive to GARS-high patients. Further, we found that knockdown of GARS significantly inhibited the proliferation, migration and invasion ability both in vivo and in vitro. Finally, we found that in patients with high GARS the expression in uEVs was also at a high level. In summary, this study provided evidence that GARS can be used as a prognostic and therapeutic marker for BC, we can detect GARS in uEVs instead of tissue, to provide a new, simple, noninvasive way to obtain prognostic and therapeutic markers for BC patients.

A61 ELUCIDATING INTESTINAL EPITHELIAL INFLAMMASOME MECHANISMS THAT REPAIR THE MUCOSAL BARRIER DURING ENTERIC INFECTION

Abstract Background To protect the gastrointestinal tract from infection, intestinal epithelial cells (IECs) lining the mucosa possess cytosolic complexes called inflammasomes which detect pathogenic insult and rapidly initiate inflammation to stop infectious spread. Active inflammasomes mediate crucial effector functions such as epithelial cell extrusion, pyroptotic cell death, and the release of interleukin (IL)-18 and prostaglandin E2 (PGE2). Recent literature has shown that IL-18 and PGE2 mediate intestinal repair following epithelial damage from DSS-induced colitis. Exogenous administration of IL-18 in inflammasome deficient mice improves survival and reduces pathology. PGE2 activates intestinal cellular reprogramming to drive intestinal wound healing. Whether inflammasome derived IL-18 and PGE2 mediate epithelial repair during enteric infection is unclear. Aims Using murine small intestinal organoids (mSIOs), we will investigate how IL-18 and PGE2 production by intestinal inflammasomes directly impacts IECs at both transcriptional and physiological levels. We hypothesize that inflammasome derived IL-18 and PGE2 will act on the intestinal epithelium resulting in transcriptional reprogramming that promotes tissue regeneration and barrier reinforcement. Methods WT and Nlrc4-/- mSIOs were stimulated with flagellin or FlaTox to activate the NAIP-NLRC4 inflammasome. The transcriptomic landscape was assessed with bulk-RNA sequencing and inflammasome activation was assessed by Western blot. IL-18 and PGE2 dependent gene targets were identified using Il-18-/- and indomethacin treated mSIOs by RT-qPCR. Results Bulk-RNA sequencing revealed an inflammasome activation dependent transcriptional signature in murine IECs upon NAIP-NLRC4 inflammasome activation. GO term analysis showed these genes to be involved in actin cytoskeleton rearrangement, epidermal growth factor signaling, and regulation of cell-cell adhesion. The expression of PGE2 gene targets were significantly reduced by indomethacin treatment while IL-18 gene targets remained unaffected in Il-18-/- IECs. FlaTox induced the same transcriptional changes but substantially amplified their expression. FlaTox but not flagellin led to a significant drop in Lgr5 (stem cells) and Lyz1 (Paneth cell) expression and an increase in Ly6a, a marker of fetal-like stem cells. Conclusions This data demonstrates that inflammasome signaling causes transcriptional reprogramming of IECs that activates pathways involved in maintaining epithelial barrier integrity. While IL-18 had no effects on gene expression at 4 hours, PGE2 paracrine signaling contributed to the expression of wound healing genes. Stronger inflammasome mediated damage with FlaTox amplified the repair response at the transcript level and we observed transient reprogramming of IECs into a fetal-like state suggesting active tissue regeneration. Funding Agencies CCC, CIHREPIC: Emerging & Pandemic Infections Consortium

Burden of cardiometabolic risk factors and vascular health

Cardiometabolic risk factors diabetes, obesity, and hypertension are highly prevalent and contribute to increased cardiovascular disease (CVD). Endothelial dysfunction precedes CVD development. The current study aimed to investigate the EC transcriptome among individuals with varying degree of cardiometabolic risk. Adult participants without CVD and various degrees of cardiometabolic risk factor burden (hypertension, diabetes, obesity) were included. Participants underwent brachial vein EC harvesting followed by RNA sequencing. To evaluate the association between cardiometabolic comorbidity burden and outcome transcripts we performed linear regression with multivariable models, adjusting for age, sex, and race/ethnicity. A total of 18 individuals were included in the present analysis (mean age 47 ± 14, 44% female, and 61% White adults). Endothelial cell RNA sequencing revealed 588 differentially expressed transcripts (p-adj <0.05) with excellent discrimination in unsupervised hierarchical clustering analysis. Gene ontology enrichment analysis revealed upregulated pathways associated with T-cell activation (NES = 2.22, p<0.001), leukocyte differentiation (NES= 2.16, p<0.001), leukocyte migration (NES= 2.12, p<0.001), regulation of cell-cell adhesion (NES= 1.91, p=0.006). Downregulated pathways of interest included endothelial cell proliferation (NES= -1.68, p=0.03) and response to interleukin-1 (NES= -1.61, p=0.04). Upregulated genes included VCAM1, CEACAM1, ADAM 17, and CD99L2, all with a log-2-fold change >3 and p-adj <0.05. These genes demonstrated a graded increase in mean normalized counts with increasing number of risk factors. We demonstrate a proinflammatory and pro-adhesive EC transcriptome associated with increased cardiometabolic risk factor burden offering insight into a potential mechanism linking these risk factors with the development of CVD.

PRELP secreted from mural cells protects the function of blood brain barrier through regulation of endothelial cell-cell integrity.

Introduction: Proline/arginine-rich end leucine-rich repeat protein (PRELP), is a small secreted proteoglycan expressed by pericytes and vascular smooth muscle cells surrounding the brain vasculature of adult mouse. Methods: We utilised a Prelp knockout (Prelp -/-) mouse model to interrogate vasculature integrity in the brain alongside performing in vitro assays to characterise PRELP application to endothelial cells lines. Our findings were supplemented with RNA expression profiling to elucidate the mechanism of how PRELP maintains neurovasculature function. Results: Prelp -/- mice presented with neuroinflammation and reducedneurovasculature integrity, resulting in IgG and dextran leakage in the cerebellum and cortex. Histological analysis of Prelp -/- mice revealed reducedcell-cell integrity of the blood brain barrier, capillary attachment of pericytes andastrocyte end-feet. RNA-sequencing analysis found that cell-cell adhesion andinflammation are affected in Prelp -/- mice and gene ontology analysis as well as gene set enrichment analysis demonstrated that inflammation related processes and adhesion related processes such as epithelial-mesenchymal transition and apical junctions were significantly affected, suggesting PRELP is a regulator of cell-cell adhesion. Immunofluorescence analysis showed that adhesion junction protein expression levels of cadherin, claudin-5, and ZO-1, was suppressed in Prelp -/- mice neurovasculature. Additionally, in vitro studies revealed that PRELP application to endothelial cells enhances cell-cell integrity, induces mesenchymal-endothelial transition and inhibits TGF-β mediated damage to cell-cell adhesion. Discussion: Our study indicates that PRELP is a novel endogenous secreted regulator of neurovasculature integrity and that PRELP application may be a potential treatment for diseases associated with neurovascular damage.

Selective Cell-Cell Adhesion Regulation via Cyclic Mechanical Deformation Induced by Ultrafast Nanovibrations.

The adoption of dynamic mechanomodulation to regulate cellular behavior is an alternative to the use of chemical drugs, allowing spatiotemporal control. However, cell-selective targeting of mechanical stimuli is challenging due to the lack of strategies with which to convert macroscopic mechanical movements to different cellular responses. Here, we designed a nanoscale vibrating surface that controls cell behavior via selective repetitive cell deformation based on a poroelastic cell model. The vibrating indentations induce repetitive water redistribution in the cells with water redistribution rates faster than the vibrating rate; however, in the opposite case, cells perceive the vibrations as a one-time stimulus. The selective regulation of cell-cell adhesion through adjusting the frequency of nanovibration was demonstrated by suppression of cadherin expression in smooth muscle cells (fast water redistribution rate) with no change in vascular endothelial cells (slow water redistribution rate). This technique may provide a new strategy for cell-type-specific mechanical stimulation.

Identification of Key lncRNAs, circRNAs, and mRNAs in Osteoarthritis via Bioinformatics Analysis.

Osteoarthritis (OA) is a common degenerative joint disorder that adversely affects the quality of life of patients. Identification of novel diagnostic biomarkers is pivotal for the early detection and prevention of OA. Dataset GSE185059 was selected from Gene Expression Omnibus database to obtain differentially expressed lncRNAs (DE-lncRNAs), mRNAs (DE-mRNAs), and circRNAs (DE-circRNAs) between OA and normal samples. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses as well as protein-protein interaction (PPI) network construction of DE-mRNAs were conducted. Hub genes were identified from PPI networks and validated by RT-qPCR. starBase database was utilized for predicting miRNAs binding with hub genes, selected DE-lncRNAs and DE-circRNAs, respectively. The competing endogenous RNA (ceRNA) networks were constructed. A total of 818 DE-mRNAs, 191 DE-lncRNAs, and 2053 DE-circRNAs were identified. The DE-mRNAs were significantly enriched in several inflammation-related GO terms and KEGG pathways such as positive regulation of cell-cell adhesion, TNF-alpha signaling pathway and NF-kappa B signaling pathway. Thirteen hub genes were identified, which were CFTR, GART, SMAD2, NCK1, TJP1, UBE2D1, EFTUD2, PRKACB, IL10, SNRPG, CHD4, RPS24, and SRSF6. OA-related DE-lncRNA/circRNA-miRNA-hub gene networks were constructed. We identified 13 hub genes and constructed the ceRNA networks related to OA, providing a theoretical basis for further research.

Ez-Metastasizing: The Crucial Roles of Ezrin in Metastasis.

Ezrin is the cytoskeletal organizer and functions in the modulation of membrane-cytoskeleton interaction, maintenance of cell shape and structure, and regulation of cell-cell adhesion and movement, as well as cell survival. Ezrin plays a critical role in regulating tumor metastasis through interaction with other binding proteins. Notably, Ezrin has been reported to interact with immune cells, allowing tumor cells to escape immune attack in metastasis. Here, we review the main functions of Ezrin, the mechanisms through which it acts, its role in tumor metastasis, and its potential as a therapeutic target.

Chronic hyperglycemia reduces the expression of intercellular adhesion molecules and increases intercellular hyperpermeability in the periodontal epithelium.

Hyperglycemia in diabetes is closely associated with periodontal disease progression. This study aimed to investigate the effect of hyperglycemia on the barrier function of gingival epithelial cells as a cause of hyperglycemia-exacerbated periodontitis in diabetes mellitus. The abnormal expression of adhesion molecules in gingival epithelium in diabetes was compared between db/db and control mice. To study the effects of hyperglycemia on interepithelial cell permeability, the mRNA and protein expressions of adhesion molecules were investigated using a human gingival epithelial cell line (epi 4 cells) in the presence of either 5.5 mM glucose (NG) or 30 mM glucose (HG). Immunocytochemical and histological analyses were performed. We also studied HG-related intracellular signaling to assess abnormal adhesion molecule expression in the cultured epi 4 cells. The results of the proteomic analysis implied the abnormal regulation of cell-cell adhesion, and mRNA and protein expression assessments revealed the significant downregulation of Claudin1 expression in the gingival tissues of db/db mice (p < .05 vs control). Similarly, the mRNA and protein expressions of adhesion molecules were lower in epi 4 cells cultured under HG conditions than in those cultured under NG conditions (p < .05). Three-dimensional culture and transmission electron microscopy revealed reduced thickness of the epithelial cell layers with no flattened apical cells and heterogeneously arranged intercellular spaces among adjacent epi 4 cells under the HG. These results were consistent with the increased permeability of epi 4 cells under the HG relative to that of cells under the NG. This abnormal expression of intercellular adhesion molecules under the HG was related to the increased expression of receptors for advanced glycation end products (AGEs) and oxidative stress relative to that seen under the NG, along with stimulation of ERK1/2 phosphorylation in epi 4 cells. High glucose-induced impairment of intercellular adhesion molecule expression in gingival epithelial cells was related to the intercellular permeability of gingival cells, representing a possible link to hyperglycemia-related AGE signaling, oxidative stress, and ERK1/2 activation.

Modeling the transition from unicellular to multicellular life.

The emergence of multicellularity represents one of the major evolutionary transitions in biology. Multiple independent evolutions of multicellularity in different lineages have demonstrated its universality. However, the building principles of multicellularity remain poorly understood. Here we present and analyze biophysical models that can account for such a transition. We focus on the mechanical aspects of this transition, i.e., how external forces like fluid flow affect the growth and break-up of such multicellular systems, and how the regulation of cell-cell adhesion should evolve in order to eventually achieve robust behavior. We analyze the phase space of possible behaviors, and we identify parameter regimes that support such an evolutionary transition.

Role of pericytes in the development of cerebral cavernous malformations.

Cerebral cavernous malformation (CCM) is caused by loss-of-function mutations in CCM1, CCM2, or CCM3 genes of endothelial cells. It is characterized by pericyte deficiency. However, the role of pericytes in CCMs is not yet clarified. We found pericytes in Cdh5Cre ERT2 ;Ccm1 fl/fl (Ccm1 ECKO ) mice had a high expression of PDGFRβ. The inhibition of pericyte function by CP-673451 aggravated the CCM lesion development. RNA-sequencing analysis revealed the molecular traits of pericytes, such as highly expressed ECM-related genes, especially Fn1. Furthermore, KLF4 coupled with phosphorylated SMAD3 (pSMAD3) promoted the transcription of fibronectin in the pericytes of CCM lesions. RGDS peptide, an inhibitor of fibronectin, decreased the lesion area in the cerebella and retinas of Ccm1 ECKO mice. Also, human CCM lesions had abundant fibronectin deposition, and pSMAD3- and KLF4-positive pericytes. These findings indicate that pericytes are essential for CCM lesion development, and fibronectin intervention may provide a novel target for therapeutic intervention in such patients.

Effects of Baicalin on Alopecia and the Associated Mechanism.

The aim of the present study was to explore the potential pharmacological mechanism of baicalin by combining network pharmacology prediction and the experimental verification of alopecia. Networks of baicalin-associated targets and alopecia-related genes were constructed using the STRING database. Potential targets and pathways associated with the therapeutic efficacy of baicalin were identified via enrichment analysis using Cytoscape and the database for annotation, visualization and integrated discovery (Metascape). The back hair of C57BL/6J mice was removed with depilatory cream to verify the therapeutic effect of baicalin. Human hair dermal papilla cells (HHDPCs) were used to explore the mechanism of action of baicalin. Network pharmacology analysis revealed that the potential targets of baicalin mainly include protein serine/threonine kinase, Src protein, epidermal growth factor receptor, and insulin-like growth factor 1 (IGF1), which were indicated to mediate neutrophil degranulation and regulation of cell-cell adhesion, vesicle lumen, cytoplasmic vesicle, membrane raft, and endopeptidase activity. Multiple pathways were identified, such as proteoglycans in cancer, PI3K/AKT, and forkhead box O signaling pathways. Following baicalin treatment for the experimental mice, the coverage, length, and weight of the hair increased in a baicalin dose-dependent manner. Moreover, the histological evaluation showed that the number of hair follicles increased after baicalin treatment and melanin formation were pronounced. In addition, baicalin induced an increase in the phosphorylated p-AKT, p-glycogen synthase kinase-3β, p-PI3K, TGF-β1, and vascular endothelial growth factor levels. Furthermore, the activation levels of key protein p-AKT were increased. Baicalin induced the proliferation of HHDPCs in vitro and significantly upregulated p-AKT, IGF1, and alkaline phosphatase. In conclusion, the present study revealed that the pharmacological mechanisms of baicalin in alopecia therapy were associated with the proliferation of DPCs, the activation of the AKT pathway, and the transmission of downstream signals, indicating that baicalin is a potential drug candidate for the clinical treatment of hair loss.

Pulmonary Fibrosis; Risk Factors and Molecular Triggers, Insight for Neo Therapeutic Approach

Abstract: Overactivation of the local pulmonary fibroblast induces hyperproduction of the extracellular matrix. A myriad of pathomorphological changes occur during lung fibrosis, including interalveolar space (interstitial) deposition due to proliferation and differentiation of resident fibroblasts, recruitment of circulating stem cells and epithelial–mesenchymal transition, highly reactive and hyperplastic alveolar epithelium. Currently, many endogenous and exogenous factors are believed to be associated with lung fibrosis development. However, pathogenetic treatment remains in the womb of development. Exploring the underlying pathophysiology is crucial for successful development of pathogenetic treatment. Several molecules termed chemokines and cytokines have been found to induce lung fibrosis, such as IL-6, IL-1β, PDGFRα, TNF-α, GM-CSF, and IL-13. However, many others, such as IL-8, RANTES, IP-10, and MIG or lymphotactin, have an antifibrosis effect. However, the pathogenesis is multifactorial and involves dysregulation of the immune system, impaired cell-cell adhesion regulation mechanisms, and loss of DNA repair. The paper aimed to thoroughly addresses the potential risk factors and molecular triggers of lung fibrosis.

Endoglycan Regulates Purkinje Cell Migration by Balancing Cell-Cell Adhesion.

The importance of cell adhesion molecules for the development of the nervous system has been recognized many decades ago. Functional in vitro and in vivo studies demonstrated a role of cell adhesion molecules in cell migration, axon growth and guidance, as well as synaptogenesis. Clearly, cell adhesion molecules have to be more than static glue making cells stick together. During axon guidance, cell adhesion molecules have been shown to act as pathway selectors but also as a means to prevent axons going astray by bundling or fasciculating axons. We identified Endoglycan as a negative regulator of cell-cell adhesion during commissural axon guidance across the midline. The presence of Endoglycan allowed commissural growth cones to smoothly navigate the floor-plate area. In the absence of Endoglycan, axons failed to exit the floor plate and turn rostrally. These observations are in line with the idea of Endoglycan acting as a lubricant, as its presence was important, but it did not matter whether Endoglycan was provided by the growth cone or the floor-plate cells. Here, we expand on these observations by demonstrating a role of Endoglycan during cell migration. In the developing cerebellum, Endoglycan was expressed by Purkinje cells during their migration from the ventricular zone to the periphery. In the absence of Endoglycan, Purkinje cells failed to migrate and, as a consequence, cerebellar morphology was strongly affected. Cerebellar folds failed to form and grow, consistent with earlier observations on a role of Purkinje cells as Shh deliverers to trigger granule cell proliferation.

Functions of Arp2/3 Complex in the Dynamics of Epithelial Tissues.

Epithelia are sheets of cells that communicate and coordinate their behavior in order to ensure their barrier function. Among the plethora of proteins involved in epithelial dynamics, actin nucleators play an essential role. The branched actin nucleation complex Arp2/3 has numerous functions, such as the regulation of cell-cell adhesion, intracellular trafficking, the formation of protrusions, that have been well described at the level of individual cells. Here, we chose to focus on its role in epithelial tissue, which is rising attention in recent works. We discuss how the cellular activities of the Arp2/3 complex drive epithelial dynamics and/or tissue morphogenesis. In the first part, we examined how this complex influences cell-cell cooperation at local scale in processes such as cell-cell fusion or cell corpses engulfment. In the second part, we summarized recent papers dealing with the impact of the Arp2/3 complex at larger scale, focusing on different morphogenetic events, including cell intercalation, epithelial tissue closure and epithelial folding. Altogether, this review highlights the central role of Arp2/3 in a diversity of epithelial tissue reorganization.

Identification of LIPH as an unfavorable biomarkers correlated with immune suppression or evasion in pancreatic cancer based on RNA-seq.

It is widely considered that pancreatic cancer (PC) is an immunosuppressive cancer. Immune-based therapies remain promising therapeutic strategies for PC. Overexpression of lipase H (LIPH) was reported to be related to immunity in cattle and has also been demonstrated to promote tumor progression in several tumors, but its role in pancreatic carcinogenesis remains unclear. Study on LIPH in PC might provide a new insight into the immunosuppression in PC. The potential biological and clinical significance of LIPH was evaluated by bioinformatics analysis. We further investigated potential associations between the expression of LIPH and tumor immune infiltration using the CIBERSORT algorithm, the ESTIMAT algorithm, and single sample gene set enrichment analysis (ssGSEA). LIPH was significantly overexpressed in tumor tissues compared with normal tissues. LIPH overexpression correlated with tumor recurrence, advanced histologic grade, and poorer overall survival (OS). Four of the most common somatic mutation, including KRAS, TP53, CDKN2A, and SMAD4, in PC were all correlated with high LIPH expression. And high LIPH expression was significantly correlated with KRAS activation and SMAD4 inactivation. Besides, LIPH expression was involved in various biological pathways such as negative regulation of cell-cell adhesion, actin cytoskeleton, EMT, angiogenesis, and signaling by MST1. And LIPH overexpression caused high infiltration of TAMs, Treg cells, and Th2/Th1, but reduced the infiltration of CD8+ T cells and Th1 cells. Our findings demonstrated that LIPH correlated with immune suppression or evasion and may function as a novel unfavorable prognostic biomarker in PC.

Identification of Prognosis-Related Genes of Acute Myeloid Leukemia

Background: Acute myeloid leukemia (AML) is a clinically and genetically heterogeneous hematological malignancy and relapse is the main reason for the poor therapeutic effect and low survival rate. Bioinformatic technology could screen out relative genes that promote the recurrence of AML, providing a theoretical basis for further improving the precision stratification treatment of AML. Methods: In this study, gene expression profiles of Dataset Acute Myeloid Leukemia (OHSU, Nature 2018) and GSE134589 were downloaded from cBioPortal and GEO, respectively. R software and limma packages were used to identify the DEGs and then run GO enrichment, KEGG pathway, and PPI network. CIBERSORTx was used to enumerate tumor-infiltrating immune cells. Prognosis-related genes were selected by univariate and multivariate Cox proportional hazards regression analyses and the expression of them were verified by GEPIA. Kaplan-Meier curve analysis could compare the survival time. ROC curve analysis was performed to predict the value of the selected genes. Results: Functional analysis showed that the up-regulated DEGs were strikingly enriched in Cytokine-cytokine receptor interaction and positive regulation of cytokine production, and the down-regulated DEGs in the regulation of cell-cell adhesion, TNF signaling pathway. CIBERSORTx analysis revealed that the immune response of AML acted as an intricate network and proceeded in a tightly regulated way. Cox analysis showed that ALDH1L2, KLK1, and LRRN2 were correlated with AML prognosis. Conclusion: ALDH1L2, KLK1, and LRRN2 are prognosis-related genes in AML, which may, together with some immune pathways, induce poor prognosis and can be used as potential biomarkers in AML treatment.

Endoglycan plays a role in axon guidance by modulating cell adhesion.

Axon navigation depends on the interactions between guidance molecules along the trajectory and specific receptors on the growth cone. However, our in vitro and in vivo studies on the role of Endoglycan demonstrate that in addition to specific guidance cue - receptor interactions, axon guidance depends on fine-tuning of cell-cell adhesion. Endoglycan, a sialomucin, plays a role in axon guidance in the central nervous system of chicken embryos, but it is neither an axon guidance cue nor a receptor. Rather, Endoglycan acts as a negative regulator of molecular interactions based on evidence from in vitro experiments demonstrating reduced adhesion of growth cones. In the absence of Endoglycan, commissural axons fail to properly navigate the midline of the spinal cord. Taken together, our in vivo and in vitro results support the hypothesis that Endoglycan acts as a negative regulator of cell-cell adhesion in commissural axon guidance.

Spatiotemporal Control Over Multicellular Migration Using Green Light Reversible Cell–Cell Interactions

The regulation of cell-cell adhesions in space and time plays a crucial role in cell biology, especially in the coordination of multicellular behavior. Therefore, tools that allow for the modulation of cell-cell interactions with high precision are of great interest to a better understanding of their roles and building tissue-like structures. Herein, the green light-responsive protein CarH is expressed at the plasma membrane of cells as an artificial cell adhesion receptor, so that upon addition of its cofactor vitamin B12 specific cell-cell interactions form and lead to cell clustering in a concentration-dependent manner. Upon green light illumination, the CarH based cell-cell interactions disassemble and allow for their reversion with high spatiotemporal control. Moreover, these artificial cell-cell interactions impact cell migration, as observed in a wound-healing assay. When the cells interact with each other in the presence of vitamin B12 in the dark, the cells form on a solid front and migrate collectively; however, under green light illumination, individual cells migrate randomly out of the monolayer. Overall, the possibility of precisely controlling cell-cell interactions and regulating multicellular behavior is a potential pathway to gaining more insight into cell-cell interactions in biological processes.

Investigation of the miRNA and mRNA Coexpression Network and Their Prognostic Value in Hepatocellular Carcinoma.

Purpose To identify pivotal differentially expressed miRNAs and genes and construct their regulatory network in hepatocellular carcinoma. Methods mRNA (GSE101728) and microRNA (GSE108724) microarray datasets were obtained from the NCBI Gene Expression Omnibus (GEO) database. Then, we identified the differentially expressed miRNAs and mRNAs. Sequentially, transcription factor enrichment and gene ontology (GO) enrichment analysis for miRNA were performed. Target genes of these differential miRNAs were obtained using packages in R language (R package multiMiR). After that, downregulated miRNAs were matched with target mRNAs which were upregulated, while upregulated miRNAs were paired with downregulated target mRNA using scripts written in Perl. An miRNA-mRNA network was constructed and visualized in Cytoscape software. For miRNAs in the network, survival analysis was performed. And for genes in the network, we did gene ontology (GO) and KEGG pathway enrichment analysis. Results A total of 35 miRNAs and 295 mRNAs were involved in the network. These differential genes were enriched in positive regulation of cell-cell adhesion, positive regulation of leukocyte cell-cell adhesion, and so on. Eight differentially expressed miRNAs were found to be associated with the OS of patients with HCC. Among which, miR-425 and miR-324 were upregulated while the other six, including miR-99a, miR-100, miR-125b, miR-145, miR-150, and miR-338, were downregulated. Conclusion In conclusion, these results can provide a potential research direction for further studies about the mechanisms of how miRNA affects malignant behavior in hepatocellular carcinoma.

Genes regulating membrane-associated E-cadherin and proliferation in adenomatous polyposis coli mutant colon cancer cells: High content siRNA screen.

Truncating mutations in the tumour suppressor gene APC occur frequently in colorectal cancers and result in the deregulation of Wnt signalling as well as changes in cell-cell adhesion. Using quantitative imaging based on the detection of membrane-associated E-cadherin, we undertook a protein coding genome-wide siRNA screen to identify genes that regulate cell surface E-cadherin in the APC-defective colorectal cancer cell line SW480. We identified a diverse set of regulators of E-cadherin that offer new insights into the regulation of cell-cell adhesion, junction formation and genes that regulate proliferation or survival of SW480 cells. Among the genes whose depletion promotes membrane-associated E-cadherin, we identified ZEB1, the microRNA200 family, and proteins such as a ubiquitin ligase UBE2E3, CDK8, sorting nexin 27 (SNX27) and the matrix metalloproteinases, MMP14 and MMP19. The screen also identified 167 proteins required for maintaining E-cadherin at cell-cell adherens junctions, including known junctional proteins, CTNND1 and CTNNA1, as well as signalling enzymes, DUSP4 and MARK2, and transcription factors, TEAD3, RUNX2 and TRAM2. A better understanding of the post-translational regulation of E-cadherin provides new opportunities for restoring cell-cell adhesion in APC-defective cells.