Epithelial Cell-cell Adhesion Research Articles

Lactate drives epithelial-mesenchymal transition in diabetic kidney disease via the H3K14la/KLF5 pathway

High levels of urinary lactate are an increased risk of progression in patients with diabetic kidney disease (DKD). However, it is still unveiled how lactate drive DKD. Epithelial-mesenchymal transition (EMT), which is characterized by the loss of epithelial cells polarity and cell-cell adhesion, and the acquisition of mesenchymal-like phenotypes, is widely recognized a critical contributor to DKD. Here, we found a switch from oxidative phosphorylation (OXPHOS) toward glycolysis in AGEs-induced renal tubular epithelial cells, thus leading to elevated levels of renal lactic acid. We demonstrated that reducing the lactate levels markedly delayed EMT progression and improved renal tubular fibrosis in DKD. Mechanically, we observed lactate increased the levels of histone H3 lysine 14 lactylation (H3K14la) in DKD. ChIP-seq & RNA-seq results showed histone lactylation contributed to EMT process by facilitating KLF5 expression. Moreover, KLF5 recognized the promotor of cdh1 and inhibited its transcription, which accelerated EMT of DKD. Additionally, nephro-specific knockdown and pharmacological inhibition of KLF5 diminished EMT development and attenuated DKD fibrosis. Thus, our study provides better understanding of epigenetic regulation of DKD pathogenesis, and new therapeutic strategy for DKD by disruption of the lactate-drived H3K14la/KLF5 pathway.

MARCH family E3 ubiquitin ligases selectively target and degrade cadherin family proteins.

Cadherin family proteins play a central role in epithelial and endothelial cell-cell adhesion. The dynamic regulation of cell adhesion is achieved in part through endocytic membrane trafficking pathways that modulate cadherin cell surface levels. Here, we define the role for various MARCH family ubiquitin ligases in the regulation of cadherin degradation. We find that MARCH2 selectively downregulates VE-cadherin, resulting in loss of adherens junction proteins at cell borders and a loss of endothelial barrier function. Interestingly, N-cadherin is refractory to MARCH ligase expression, demonstrating that different classical cadherin family proteins are differentially regulated by MARCH family ligases. Using chimeric cadherins, we find that the specificity of different MARCH family ligases for different cadherins is conferred by the cadherin transmembrane domain. Further, juxta-membrane lysine residues are required for cadherin degradation by MARCH proteins. These findings expand our understanding of cadherin regulation and highlight a new role for mammalian MARCH family ubiquitin ligases in differentially regulating cadherin turnover.

Notch1 cortical signaling regulates epithelial architecture and cell-cell adhesion.

Notch receptors control tissue morphogenic processes that involve coordinated changes in cell architecture and gene expression, but how a single receptor can produce these diverse biological outputs is unclear. Here, we employ a 3D model of a human ductal epithelium to reveal tissue morphogenic defects result from loss of Notch1, but not Notch1 transcriptional signaling. Instead, defects in duct morphogenesis are driven by dysregulated epithelial cell architecture and mitogenic signaling which result from the loss of a transcription-independent, Notch1 cortical signaling mechanism that ultimately functions to stabilize adherens junctions and cortical actin. We identify that Notch1 localization and cortical signaling are tied to apical-basal cell restructuring and discover that a Notch1-FAM83H interaction underlies control of epithelial adherens junctions and cortical actin. Together, these results offer new insights into Notch1 signaling and regulation and advance a paradigm in which transcriptional and cell adhesive programs might be coordinated by a single receptor.

Association of E-cadherin with epidermal growth factor receptor in squamous cell carcinoma of oral cavity

Oral cancer is the sixth most common cancer worldwide. Despite new modalities of treatment there has been no significant improvement in mortality and morbidity. E-cadherin responsible for cell-cell adhesion in epithelial tissues. It plays role in establishment and maintenance of polarity and structural integrity. Low expression helps in process of carcinogenesis. Epidermal growth factor receptor (EGFR) overexpression is found in majority of oral squamous cell carcinoma and association have been made between increased expression levels and an aggressive phenotype.To study the association of E-cadherin with epidermal growth factor receptor in different grades of oral squamous cell carcinoma.After taking informed consent from patients 75 cases of OSCC were included in the study and subjected to immunohistochemistry of E-cadherin and EGFR.It was concluded from the study that with decrease in differentiation of OSCC expression of E- cadherin decrease while expression of EGFR increases. On correlating both were found to be inversely proportional to each other.During EMT there is loss of cell adhesion molecules. In our study with decrease differentiation there is loss of E-cadherin. E-Cadherin expression was inversely correlated to EGFR expression.

184 The role of the Laminin 332 in cholesterol transport in dry and Aged skin

The skin provides a barrier function mediated by a combination of cornified epithelial cells, cell-cell adhesions and epidermal lipids. The barrier function is compromised in old age which is exemplified by features such as improper lipid metabolism and flattened dermal-epidermal junction. Laminin 332 is a skin basement membrane glycoprotein which was shown to be decreased in aged skin. We have previously demonstrated that the loss of laminin 332 leads to an upregulation of cholesterol biosynthesis genes and alters the skin’s lipid profile. We identified that this change is due to an impaired intracellular cholesterol transport. To understand the mechanism around cholesterol transport we have identified a panel of proteins of interest for further investigation. We investigated the role that laminin 332, actin and microtubule disruption have on both subcellular location of our proteins of interest and cholesterol transport. We have demonstrated that NPC2, Myo5b and e-cadherin are decreased in laminin α3 knockdown nTERT keratinocytes compared to shC controls. Interestingly, NPC1, a binding partner for NPC2, was shown to be increased in the laminin α3 knockdown nTERT keratinocytes. Normal levels and localisation of each protein can be restored by the addition of recombinant laminin 332. We have also demonstrated that in keratinocytes free cholesterol localises to Rab11a-positive vesicles which is a binding partner for Myo5b. By using actin- and microtubule-disrupting drugs, we have shown that it is the loss of actin that’s driving the observed phenotype. These findings suggest that the disrupted cholesterol transport and impaired barrier function in laminin α3 knockdown is due to lower levels of Myo5b and e-cadherin resulting from a disorganised actin cytoskeleton with a concomitant weakening of cell-cell contacts.

E-Cadherin Expression Distinguishes Mouse from Human Hematopoiesis in the Basophil and Erythroid Lineages.

E-cadherin is a key regulator of epithelial cell-cell adhesion, the loss of which accelerates tumor growth and invasion. E-cadherin is also expressed in hematopoietic cells as well as epithelia. The function of hematopoietic E-cadherin is, however, mostly elusive. In this study, we explored the validity of mouse models to functionally investigate the role of hematopoietic E-cadherin in human hematopoiesis. We generated a hematopoietic-specific E-cadherin knockout mouse model. In mice, hematopoietic E-cadherin is predominantly expressed within the basophil lineage, the expression of which is dispensable for the generation of basophils. However, neither E-cadherin mRNA nor protein were detected in human basophils. In contrast, human hematopoietic E-cadherin marks the erythroid lineage. E-cadherin expression in hematopoiesis thereby revealed striking evolutionary differences between the basophil and erythroid cell lineage in humans and mice. This is remarkable as E-cadherin expression in epithelia is highly conserved among vertebrates including humans and mice. Our study therefore revealed that the mouse does not represent a suitable model to study the function of E-cadherin in human hematopoiesis and an alternative means to study the role of E-cadherin in human erythropoiesis needs to be developed.

Late domain dependent E-cadherin recruitment into extracellular vesicles.

E-cadherin, a transmembrane protein involved in epithelial cell-cell adhesion and signaling, is found in exosomal fractions isolated from human body fluids. A cellular mechanism for recruitment of E-cadherin into extracellular vesicles (EVs) has not yet been defined. Here, we show that E-cadherin is incorporated into the membrane of EVs with the extracellular domain exposed at the vesicle surface. This recruitment depends on the endosomal sorting complex required for transport I (ESCRT-I) component Tsg101 and a highly conserved tetrapeptide P(S/T)AP late domain motif in the cytoplasmic tail of E-cadherin that mediates interaction with Tsg101. Mutation of this motif results in a loss of interaction and a dramatic decrease in exosomal E-cadherin secretion. We conclude, that the process of late domain mediated exosomal recruitment is exerted by this endogenous non-ESCRT transmembrane protein.

1096P Identifying predictive biomarkers for long term response on immunotherapy in non-small cell lung cancer (NSCLC)

Programmed Death 1 (PD-1) pathway targeting immune checkpoint inhibitors (ICIs) are standard of care for advanced NSCLC. Today, histological expression of PD-1 ligand (PD-L1) is the only approved predictive biomarker for response. Yet, ICI treatment can lead to durable or absence of response in patients with low/absent or high PD-L1 resp., indicating that PD-L1 expression is not an ideal biomarker. Further, it remains unclear whether we can define a subgroup that remains progression free after therapy withdrawal. This retrospective pilot study aspires to identify superior biomarkers for long term vs nonresponsive patients and to guide ICI therapy duration. Advanced NSCLC patients with complete and persistent metabolic response (‘responders’, n=5) versus absence of response (‘non-responders’ with >60% PD-L1, n=5) upon ICI therapy were included. Inflammation-related blood biomarkers were compared. From pre-treatment biopsies, RNA and DNA was extracted for respective transcriptional and genomic analysis. Differential gene expression analysis (DESeq2 package) and gene ranking-based gene set enrichment analysis were performed to identify gene oncology biological processes. We used the Mutect2T tool for DNA reads variant calling and tumor mutational burden (TMB) evaluation. While none of the investigated blood biomarkers showed a significant difference between both cohorts, RNA analysis showed 546 significantly expressed genes (p< 0,1). In brief, upregulated genes in the responder group were linked to immune effector response, phagocytosis and myeloid/mast cell activation. Significantly downregulated genes in the responder group were more abundant and mainly linked to epithelial development, cell-cell adhesion, cytoskeletal rearrangements, and endocrine metabolic processes. While no differences in the TMB profiles were observed, the non-responders harbored more mutations in the following genes: TP53, CDKN2A, MSH6, GNAQ and CSMD3. Evaluation of two extremes of the ICI response spectrum in NSCLC patients showed significant differences with biomarker potential in terms of patient stratification and duration of ICI therapy.

O081 Investigating the FLYWCH1/ β-catenin signalling in pancreatic cancer

Abstract Introduction β-catenin is a protein molecule of the E-cadherin/catenin adhesion complex that maintains epithelial cell-cell adhesion and intracellular signalling. The mutation and overexpression of β-catenin leads to cancer, including pancreatic ductal adenocarcinoma (PDAC). FLYWCH1 is a newly identified protein with zinc-finger type DNA-binding domain that interacts with nuclear β-catenin, leading to increased cell-cell and cell-matrix adhesion in cancer and stem cells. This study aimed to explore the roles of crosstalk between FLYWCH1 and Wnt/β-catenin signalling for the first time in pancreatic cancer cells. Methods We performed Western Blot analysis for the extraction of FLYWCH1/β-catenin, E-cadherin and GSK3-b in AsPc-1, PANC-1, and MIA PaCa-2 pancreatic cancer cell lines. Recommended concentrations of antibodies were used for the detection of proteins of interest. Tubulin was used as a loading control. Fluorescent detection was used, and the density of detected proteins were measured. Results Our results demonstrate evidence of differential expression of FLYWCH1 in pancreatic cancer cells. PANC-1 had less expression of FLYWCH1, but expression was moderate in AsPC-1. E-cadherin, β catenin, and GSK3-b were also expressed. These data suggest that FLYWCH1 levels correlated with unphosphorylated β-catenin to suppress the transcriptional product via controlling the aberrant Wnt/β-catenin pathway while E-cadherin promoted the cell-cell attachment. Conclusion These results suggest that Wnt1/β-catenin activity is negatively correlated with FLYWCH1 expression in pancreatic cancer cells. Thus, FLYWCH1 could have tumour suppressive activities. Future studies are required to elucidate their therapeutic and biomarkers efficacy. Take-home message FLYWCH1 is a newly identified protein could control B-catenin expression which leads tumour suppression. Thus, FLYWCH1 would be a therapeutic target for pancreatic cancer treatment in the future.

P-Cadherin Regulates Intestinal Epithelial Cell Migration and Mucosal Repair, but Is Dispensable for Colitis Associated Colon Cancer.

Recurrent chronic mucosal inflammation, a characteristic of inflammatory bowel diseases (IBD), perturbs the intestinal epithelial homeostasis resulting in formation of mucosal wounds and, in most severe cases, leads to colitis-associated colon cancer (CAC). The altered structure of epithelial cell-cell adhesions is a hallmark of intestinal inflammation contributing to epithelial injury, repair, and tumorigenesis. P-cadherin is an important adhesion protein, poorly expressed in normal intestinal epithelial cells (IEC) but upregulated in inflamed and injured mucosa. The goal of this study was to investigate the roles of P-cadherin in regulating intestinal inflammation and CAC. P-cadherin expression was markedly induced in the colonic epithelium of human IBD patients and CAC tissues. The roles of P-cadherin were investigated in P-cadherin null mice using dextran sulfate sodium (DSS)-induced colitis and an azoxymethane (AOM)/DSS induced CAC. Although P-cadherin knockout did not affect the severity of acute DSS colitis, P-cadherin null mice exhibited faster recovery after colitis. No significant differences in the number of colonic tumors were observed in P-cadherin null and control mice. Consistently, the CRISPR/Cas9-mediated knockout of P-cadherin in human IEC accelerated epithelial wound healing without affecting cell proliferation. The accelerated migration of P-cadherin depleted IEC was driven by activation of Src kinases, Rac1 GTPase and myosin II motors and was accompanied by transcriptional reprogramming of the cells. Our findings highlight P-cadherin as a negative regulator of IEC motility in vitro and mucosal repair in vivo. In contrast, this protein is dispensable for IEC proliferation and CAC development.

Aquaporin-5 in breast cancer.

The water channel aquaporin‐5 (AQP5) is essential in transepithelial water transport in secretory glands. AQP5 is ectopically overexpressed in breast cancer, where expression is associated with lymph node metastasis and poor prognosis. Besides the role in water transport, AQP5 has been found to play a role in cancer metastasis, migration, and proliferation. AQP5 has also been shown to be involved in the dysregulation of epithelial cell–cell adhesion; frequently observed in cancers. Insight into the underlying molecular mechanisms of how AQP5 contributes to cancer development and progression is essential for potentially implementing AQP5 as a prognostic biomarker and to develop targeted intervention strategies for the treatment of breast cancer patients.

Tuning Epithelial Cell-Cell Adhesion and Collective Dynamics with Functional DNA-E-Cadherin Hybrid Linkers.

The binding strength between epithelial cells is crucial for tissue integrity, signal transduction and collective cell dynamics. However, there is no experimental approach to precisely modulate cell–cell adhesion strength at the cellular and molecular level. Here, we establish DNA nanotechnology as a tool to control cell–cell adhesion of epithelial cells. We designed a DNA-E-cadherin hybrid system consisting of complementary DNA strands covalently bound to a truncated E-cadherin with a modified extracellular domain. DNA sequence design allows to tune the DNA-E-cadherin hybrid molecular binding strength, while retaining its cytosolic interactions and downstream signaling capabilities. The DNA-E-cadherin hybrid facilitates strong and reversible cell–cell adhesion in E-cadherin deficient cells by forming mechanotransducive adherens junctions. We assess the direct influence of cell–cell adhesion strength on intracellular signaling and collective cell dynamics. This highlights the scope of DNA nanotechnology as a precision technology to study and engineer cell collectives.

Clinical and serological predictors of relapse in pemphigus: a study of 143 patients.

SummaryBackgroundPemphigus is an autoimmune bullous disease mediated by autoantibodies targeting epithelial cell–cell adhesion molecules. Predictors of relapse have not yet been clearly identified.AimsTo identify factors at diagnosis and during follow‐up that could be predictors of relapse.MethodsClinical and immunopathological data at diagnosis, clinical remission and first relapse from patients with pemphigus vulgaris or foliaceus and at least a 36‐month follow‐up were collected retrospectively. Based on the autoantibody profile at diagnosis, three serological patient subsets were devised: (i) anti‐desmoglein (Dsg)1‐positive and anti‐Dsg3‐negative; (iii) anti‐Dsg1‐negative and anti‐Dsg3‐positive; and (iii) anti‐Dsg1‐positive and anti‐Dsg3‐positive.ResultsData from 143 patients were collected. No significant differences were found between relapsers (n = 90) and nonrelapsers (n = 53) for time to remission or for anti‐Dsg1 and anti‐Dsg3 titres at diagnosis and remission. In the analysis of all patients, a higher risk of relapse was found for a body surface area (BSA) score of 3 compared with BSA < 3 (OR = 3.30, 95% CI 1.17–9.28; P = 0.02) and for a positive titre of either anti‐Dsg1 or anti‐Dsg3 autoantibodies at remission compared with both being negative (OR = 2.42, 95% CI 1.21–4.85, P = 0.01). In patients who were anti‐Dsg3‐positive and anti‐Dsg1‐negative at diagnosis, failure to achieve anti‐Dsg3 negativity at clinical remission was a significant predictor of relapse (OR = 7.89, 95% CI 2.06–30.21; P < 0.01). Similarly, failure to achieve anti‐Dsg1 negativity at clinical remission was a significant predictor of relapse in patients with both anti‐Dsg1 and anti‐Dsg3 positivity at diagnosis (OR = 5.74, 95% CI 1.15–28.61; P = 0.03), but not in those who were anti‐Dsg1‐positive/anti‐Dsg3‐negative at diagnosis (OR = 1.08, 95% CI 0.27–4.30; P = 0.91).ConclusionRegardless of pemphigus subtype, autoantibody titre negativity at clinical remission in patients classified based on their anti‐Dsg1 and anti‐Dsg3 profile at diagnosis and BSA were useful tools in predicting relapse.

Cryptosporidium rhoptry effector protein ROP1 injected during invasion targets the host cytoskeletal modulator LMO7

The parasite Cryptosporidium invades and replicates in intestinal epithelial cells and is a leading cause of diarrheal disease and early childhood mortality. The molecular mechanisms that underlie infection and pathogenesis are largely unknown. Here, we delineate the events of host cell invasion and uncover a mechanism unique to Cryptosporidium. We developed a screen to identify parasite effectors, finding the injection of multiple parasite proteins into the host from the rhoptry organelle. These factors are targeted to diverse locations within the host cell and its interface with the parasite. One identified effector, rhoptry protein 1 (ROP1), accumulates in the terminal web of enterocytes through direct interaction with the host protein LIM domain only 7 (LMO7) an organizer of epithelial cell polarity and cell-cell adhesion. Genetic ablation of LMO7 or ROP1 in mice or parasites, respectively, impacts parasite burden invivo in opposite ways. Taken together, these data provide molecular insight into how Cryptosporidium manipulates its intestinal host niche.

Improved epithelial cell-cell adhesion using molecular mobility of supramolecular surfaces.

Cells can sense the surrounding microenvironmental properties including contact with biomaterials. Although in vitro cell fates in response to the physical properties of cell-adhesive materials have been widely reported, their influence on cell-cell adhesion is unclear. Here, we investigated the role of molecular mobility on polyrotaxane surfaces in epithelial cell-cell adhesion. Polyrotaxane surfaces with high mobility induced cytoplasmic yes-associated protein (YAP) localization in epithelial cells, whereas those with low mobility induced nuclear YAP localization, suggesting that YAP localization is switched by the mobility of the polyrotaxane surface. The cytoplasmic YAP localization increased the expression of tight junction-associated genes. A scratch assay revealed that although the epithelial cells on the low mobile surface rapidly initiated their migration, the cells on the highly mobile surface delayed their migration. Thus, this finding suggests that polyrotaxane surfaces with higher mobility induce cytoplasmic YAP localization, leading to stronger cell-cell adhesion. The polyrotaxane biointerface is promising as a powerful tool to improve the physical immune system and repair biological tissues.

A Screen for &lt;i&gt;Cryptosporidium&lt;/i&gt; Rhoptry Proteins Identifies ROP1 as an Effector Targeting the Host Cytoskeletal Modulator LMO7

The parasite Cryptosporidium invades and replicates in intestinal epithelial cells and is a leading cause of diarrheal disease and early childhood mortality. The molecular mechanisms that underlie infection and pathogenesis are largely unknown. Here we delineate the events of host cell invasion and uncover a mechanism unique to Cryptosporidium. We develop a screen to identify parasite effectors and show injection of multiple parasite proteins into the host from the rhoptry organelle. These factors are targeted to diverse locations within the host cell and its interface with the parasite. One of them, ROP1 accumulates in the enterocyte’s terminal web through direct interaction with the host protein LMO7, an organizer of epithelial cell polarity and cell-cell adhesion. Genetic ablation of LMO7 and ROP1 in mice and parasites respectively, show that both impact parasite burden in vivo. Taken together, these studies provide molecular insight into how Cryptosporidium manipulates its intestinal host niche.

Cell Junction Mechanics beyond the Bounds of Adhesion and Tension.

Cell-cell junctions, in particular adherens junctions, are major determinants of tissue mechanics during morphogenesis and homeostasis. In attempts to link junctional mechanics to tissue mechanics, many have utilized explicitly or implicitly equilibrium approaches based on adhesion energy, surface energy, and contractility to determine the mechanical equilibrium at junctions. However, it is increasingly clear that they have significant limitations, such as that it remains challenging to link the dynamics of the molecular components to the resulting physical properties of the junction, to its remodeling ability, and to its adhesion strength. In this perspective, we discuss recent attempts to consider the aspect of energy dissipation at junctions to draw contact points with soft matter physics where energy loss plays a critical role in adhesion theories. We set the grounds for a theoretical framework of the junction mechanics that bridges the dynamics at the molecular scale to the mechanics at the tissue scale.

Abstract 3983: Direct contact of heterogeneous fibroblasts with cancer cells regulates the invasive phenotype of prostate cancer cells

Abstract In the tumor microenvironment of prostate cancer (PCa), cancer cells frequently invade the surrounding stroma in the way of single cell migration (SCM) or collective cell migration (CCM). This phenomenon can be responsible for the heterogeneous formation of structural atypia such as Gleason pattern. Generally, PCa cells undergo a phenotypic change which is called the epithelial-to-mesenchymal transition (EMT), e.g., downregulation of epithelial cell-cell adhesion molecules such as E-cadherin and gain of mesenchymal morphology and motility. The surrounding stroma is mainly composed of fibroblasts and extracellular matrix (ECM). We hypothesize that direct contact-mediated interactions at the interface between PCa cells and fibroblasts/ECM can trigger numerous changes in PCa cells including morphology and motility. In this study, we investigated the roles of fibroblasts in the three-dimensional (3D) morphogenesis of PCa cells on a viscous substrate. To examine the effects of fibroblasts on the 3D morphogenesis of PCa cells on Matrigel, we mixed human PCa cell line LNCaP cells with commercially available normal human prostate stromal cells (PrSC) or nine primary cultures of prostate fibroblasts (pcPrFs and NPFs) isolated from patients with PCa and bladder cancer. The 3D morphogenesis of LNCaP cells mixed with fibroblasts on Matrigel was confirmed by E-cadherin immunohistochemical staining. All ten fibroblasts alone were aggregated on Matrigel, whereas LNCaP cells alone were not. LNCaP cells mixed with six fibroblasts (PrSC, pcPrF-M5, pcPrF-M23, pcPrF-M24, pcPrF-M28, and pcPrF-M31) formed a deep crater-like hole on Matrigel. In the 3D structure, the upper and lower tiers were composed of LNCaP cells and fibroblasts, respectively. Of note, direct contact of four fibroblasts (NPF-M13, pcPrF-M7, pcPrF-M10, and pcPrF-M26) with LNCaP cells decreased the aggregation of fibroblasts on Matrigel. Five of six fibroblasts (PrSC, pcPrF-M5, pcPrF-M23, pcPrF-M28, and pcPrF-M31) induced SCM of LNCaP cells, while only one fibroblasts (pcPrF-M24) induced CCM. In the scratch assay, the cell motility of CCM-inducing fibroblasts was slower than that of SCM-inducing fibroblasts. Expression pattern of primary cilia in SCM-inducing fibroblasts was changed by mixing with LNCaP cells, whereas that in CCM-inducing fibroblasts was not. PCa is quite interesting because of the multi-focal and heterologous progression of primary tumors. The heterogeneous stromal compartment in PCa tissues contains multiple populations of fibroblasts that are associated with morphology and motility of PCa cells. Here our results showed that direct contact of heterogeneous fibroblasts with PCa cells on Matrigel regulated the invasive phenotype of PCa cells such as SCM and CCM. Impairing the malignant phenotype of fibroblasts in PCa tissues, e.g., differentiation therapy targeting tumor stroma, may abrogate PCa cell invasion. Citation Format: Kenichiro Ishii, Yasuhisa Nakagawa, Taku Shirai, Masako Ichishi, Masaya Fujiwara, Daisuke Kato, Chise Matsuda, Yoshifumi Hirokawa, Yoshiki Sugimura, Masaki Inagaki, Masatoshi Watanabe. Direct contact of heterogeneous fibroblasts with cancer cells regulates the invasive phenotype of prostate cancer cells [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3983.

A Simple Method to Test Mechanical Strain on Epithelial Cell Monolayers Using a 3D-Printed Stretcher.

With the realization that mechanical forces mediate many biological processes and contribute to disease progression, researchers are focusing on developing new methods to understand the role of mechanotransduction in biological systems. Despite recent advances in stretching devices that analyze the effects of mechanical strain in vitro, there are still possibilities to develop new equipment. For example, many of these devices tend be expensive, whereas few have been designed to assess the effects of mechanical strain driven by the extracellular matrix (ECM) to epithelial cell monolayers and to cell-cell adhesion. In this chapter, we introduce a cost-efficient, user-friendly, 3D-printed stretching device that can be used to test the effects of mechanical strain on cultured epithelial cells. Evaluation of the device using speckle-tracking shows homogeneous strain distribution along the horizontal plane of membranes at 2.5% and 5% strains, supporting the reliability of the device. Since cell-cell junctions are mechanosensitive protein complexes, we hereby used this device to examine effects on cell-cell adhesion. For this, we used colon epithelial Caco2 cell monolayers that well-differentiate in culture and form mature adherens junctions. Subjecting Caco2 cells to 2.5% and 5% strain using our device resulted in significant reduction in the localization of the core adherens junction component E-cadherin at areas of cell-cell contact and its increased translocation to the cytoplasm, which in agreement with other methodologies showing that increased ECM-driven strain negatively affects cell-cell adhesion. In summary, we here present a new, cost-effective, homemade device that can be reliably used to examine effects of mechanical strain on epithelial cell monolayers and cell-cell adhesion, in vitro.

Adaptation of Neisseria gonorrhoeae to the Female Reproductive Tract.

Gonorrhea, caused by Neisseria gonorrhoeae, is a common sexually transmitted infection and an urgent public health problem. Humans are the exclusive host, and the genital tract with heterogeneous epithelia is the primary niche of this bacterium, creating unique challenges for understanding its pathogenesis. The cervical tissue explant model that we have developed enabled us to show that the properties of the epithelial cells in the female reproductive tract are the main factors driving gonococcal adaptation. Gonococcal variants that colonize strongly and penetrate poorly, thereby causing asymptomatic infection, survive better in the cervix. Gonococci adapt to different epithelial cell types by varying their surfaces and modulating distinct epithelial cell-cell adhesion complexes through manipulation of host cell signaling. These findings provide critical new insights on the mechanisms by which N. gonorrhoeae adapts to the human mucosal surface and causes asymptomatic infection.