Selective Cell Adhesion Research Articles

Proteomics and Incident Kidney Failure in Individuals With CKD: The African American Study of Kidney Disease and Hypertension and the Boston Kidney Biopsy Cohort

Individuals with chronic kidney disease (CKD) are at increased risk of morbidity and mortality, particularly as they progress to kidney failure. Identifying circulating proteins that underlie kidney failure development may guide the discovery of new targets for intervention. Prospective cohort. 703 African American Study of Kidney Disease and Hypertension (AASK) and 434 Boston Kidney Biopsy Cohort (BKBC) participants with baseline proteomics data. Circulating proteins measured using SomaScan. Kidney failure, defined as dialysis initiation or kidney transplantation. Using adjusted Cox models, we studied associations of 6,284 circulating proteins with kidney failure risk separately in AASK and BKBC and meta-analyzed results. We then performed gene set enrichment analyses to identify underlying perturbations in biological pathways. In separate data sets with kidney-tissue level gene expression, we ascertained dominant regions of expression and correlated kidney tubular gene expression with fibrosis and estimated glomerular filtration rate (eGFR). Over median follow-up periods of 8.8 and 3.1 years, 210 AASK (mean age: 55 years, 39% female, mean GFR: 46mL/min/1.73m2) and 115 BKBC (mean age: 54 years, 47% female, mean eGFR: 51mL/min/1.73m2) participants developed kidney failure, respectively. We identified 143 proteins that were associated with incident kidney failure, of which only 1 (Testican-2) had a lower risk. Notable proteins included those related to vascular permeability (endothelial cell-selective adhesion molecule), glomerulosclerosis (ephrin-A1), glomerular development (ephrin-B2), intracellular sorting/transport (vesicular integral-membrane protein VIP36), podocyte effacement (pigment epithelium-derived factor), complement activation (complement decay-accelerating factor), and fibrosis (ephrin-A1, ephrin-B2, and pigment epithelium-derived factor). Gene set enrichment analyses detected overrepresented pathways that could be related to CKD progression, such as ephrin signaling, cell-cell junctions, intracellular transport, immune response, cell proliferation, and apoptosis. At the kidney level, glomerular expression predominated for genes corresponding to circulating proteins of interest, and several gene expression levels were correlated with eGFR and/or fibrosis. Possible residual confounding. Multimodal data identified proteins and pathways associated with the development of kidney failure.

Patterning of COC Polymers by Middle‐Energy Ion Beams for Selective Cell Adhesion in Microfluidic Devices

AbstractMicrofluidic devices play a crucial role in advanced cell biology applications, including cell separations, cultivations, migration and interaction studies, diagnostic devices, and organ‐on‐chips. One of the frequent purposes of such devices is the ability to selectively address the attachment of cells at defined locations on the surface. This study explores the application of middle‐energy carbon, oxygen, and nitrogen ions to locally modify the surface of cyclic olefin copolymer (COC) thermoplastic material, allowing selective cell growth on patterned polymer surfaces. The investigation considers ion element type, ion beam energy, and ion irradiation fluence, analyzing their influence on the modification effect. Characterization of the modified surfaces involves various surface‐analytical methods such as contact angle, energy dispersive spectroscopy (SEM‐EDX), atomic force microscopy (AFM), x‐ray photoelectron spectroscopy (XPS), rutherford backscattering spectrometry (RBS), and elastic recoil detection analysis (ERDA). The study extends to practical aspects, with a representative cancer cell line, MCF‐7, grown on the patterned surface to evaluate the degree of selective attachment. Additionally, the stability of the irradiated patterns is tested under elevated temperatures beyond the glass transition temperature (Tg), demonstrating the compatibility of the approach with hot embossing technology. The findings underscore the potential of ion beam treatment for COC in cell‐biology‐related applications, offering insights into surface modification techniques for enhanced functionality in microfluidic devices.

Role of endothelial cell-selective adhesion molecule in the regulation of pulmonary vascular resistance

Endothelial cell-selective adhesion molecule (ESAM) is a member of the endothelial cell junction adhesion molecules family, which plays an important role in the maintenance of endothelial barrier function in the pulmonary circulation. The role of ESAM in affecting pulmonary vascular resistance remains unknown. To examine the role of ESAM in pulmonary vascular resistance, whole lungs were isolated from 16-18 weeks old ESAM knock out (KO) mice and wild type (WT) littermates, ventilated and perfused. We found that pulmonary vascular resistance is significantly increased in the lung of ESAM KO mice compared to WT mice. Bradykinin-induced, endothelium-dependent reduction in the pulmonary vascular resistance was impaired in ESAM KO mice, whereas the direct NO donor, sodium nitroprusside-induced endothelium independent responses remained similar in WT and ESAM KO mice. U46619 mediated increases in pulmonary vascular resistance was significantly higher in ESAM KO mice. Inhibition of the NO synthesis with the L-NAME (0.2 mM for 10 minutes) augmented the U46619-mediated increase in pulmonary vascular resistance in WT mice, but it did not affect the U46619 response in the ESAM KO mice. The mRNA expression of pro-inflammatory cytokines, including interleukin-6 and tumor necrosis factor, was increased in the lungs of ESAM KO mice, whereas expression of collagen isoforms (type I and type III) and fibronectin were similar in WT and ESAM KO mice. Collectively, we propose that ESAM plays an important role in the maintenance of pulmonary vascular resistance, likely via preserving endothelial nitric oxide production in pulmonary arteries. AHA predoctoral award ID 917057. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Development of L-phenylalanine-grafted poly (vinyl alcohol) scaffold for selective capturing of cancer cells

Breast cancer is the most common cancer and the leading cause of cancer death in women. The majority of deaths from breast cancer do not result from the primary tumor itself but from metastasis to other organs in the body. Here, we report the development of a novel polymeric material that selectively traps breast cancer cells. The cancer cell-capturing polymer was synthesized by grafting L-phenylalanine onto a biocompatible poly(vinyl alcohol) (PVA-Phe). L-phenylalanine exhibits high affinity to L-type amino acid transporter 1 (LAT1), which is overexpressed on various cancer cells. We evaluated cancer cell-selective adhesion ability of PVA-Phe using MCF-7, a human hormone receptor-positive breast cancer model cell expressing LAT1. Our results suggest that LAT1 on cancer cells recognizes the L-phenylalanine and that MCF-7 selectively adheres to the synthesized PVA-Phe. For patients at risk of cancer recurrence, we expect that PVA-Phe synthesized in this study could serve to capture the remaining cancer cells when implanted in the body. Together with an appropriate scaffold that functions to attract cancer cells, PVA-Phe may have the potential to completely prevent cancer recurrence.

Integrated causal inference modeling uncovers novel causal factors and potential therapeutic targets of Qingjin Yiqi granules for chronic fatigue syndrome

Objective: Chronic fatigue syndrome (CFS) is a prevalent symptom of post-coronavirus disease 2019 (COVID-19) and is associated with unclear disease mechanisms. The herbal medicine Qingjin Yiqi granules (QJYQ) constitute a clinically approved formula for treating post-COVID-19; however, its potential as a drug target for treating CFS remains largely unknown. This study aimed to identify novel causal factors for CFS and elucidate the potential targets and pharmacological mechanisms of action of QJYQ in treating CFS. Methods: This prospective cohort analysis included 4,212 adults aged ≥65 years who were followed up for 7 years with 435 incident CFS cases. Causal modeling and multivariate logistic regression analysis were performed to identify the potential causal determinants of CFS. A proteome-wide, two-sample Mendelian randomization (MR) analysis was employed to explore the proteins associated with the identified causal factors of CFS, which may serve as potential drug targets. Furthermore, we performed a virtual screening analysis to assess the binding affinity between the bioactive compounds in QJYQ and CFS-associated proteins. Results: Among 4,212 participants (47.5% men) with a median age of 69 years (interquartile range: 69–70 years) enrolled in 2004, 435 developed CFS by 2011. Causal graph analysis with multivariate logistic regression identified frequent cough (odds ratio: 1.74, 95% confidence interval [CI]: 1.15–2.63) and insomnia (odds ratio: 2.59, 95% CI: 1.77–3.79) as novel causal factors of CFS. Proteome-wide MR analysis revealed that the upregulation of endothelial cell-selective adhesion molecule (ESAM) was causally linked to both chronic cough (odds ratio: 1.019, 95% CI: 1.012–1.026, P = 2.75 e−05) and insomnia (odds ratio: 1.015, 95% CI: 1.008–1.022, P = 4.40 e−08) in CFS. The major bioactive compounds of QJYQ, ginsenoside Rb2 (docking score: −6.03) and RG4 (docking score: −6.15), bound to ESAM with high affinity based on virtual screening. Conclusions: Our integrated analytical framework combining epidemiological, genetic, and in silico data provides a novel strategy for elucidating complex disease mechanisms, such as CFS, and informing models of action of traditional Chinese medicines, such as QJYQ. Further validation in animal models is warranted to confirm the potential pharmacological effects of QJYQ on ESAM and as a treatment for CFS.

Transcriptomic analysis of glucosidase II beta subunit (GluIIß) knockout A549 cells reveals its roles in regulation of cell adhesion molecules (CAMs) and anti-tumor immunity

Glucosidase II beta subunit (GluIIß), encoded from PRKCSH, is a subunit of the glucosidase II enzyme responsible for quality control of N-linked glycoprotein folding and suppression of GluIIß led to inhibitory effect of the receptor tyrosine kinase (RTKs) activities known to be critical for survival and development of cancer. In this study, we investigated the effect of GluIIß knockout on the global gene expression of cancer cells and its impact on functions of immune cells. GluIIß knockout lung adenocarcinoma A549 cell line was generated using CRISPR/Cas9-based genome editing system and subjected to transcriptomic analysis. Among 23,502 expressed transcripts, 1068 genes were significantly up-regulated and 807 genes greatly down-regulated. The KEGG enrichment analysis showed significant down-regulation of genes related extracellular matrix (ECM), ECM-receptor interaction, cytokine-cytokine receptor interaction and cell adhesion molecules (CAMs) in GluIIß knockout cells. Of 9 CAMs encoded DEG identified by KEGG enrichment analysis, real time RT-PCR confirmed 8 genes to be significantly down-regulated in all 3 different GluIIß knockout clones, which includes cadherin 4 (CDH4), cadherin 2 (CDH2), versican (VCAN), integrin subunit alpha 4 (ITGA4), endothelial cell-selective adhesion molecule (ESAM), CD274 (program death ligand-1 (PD-L1)), Cell Adhesion Molecule 1 (CADM1), and Nectin Cell Adhesion Molecule 3 (NECTIN3). Whereas PTPRF (Protein Tyrosine Phosphatase Receptor Type F) was significantly decreased only in 1 out of 3 knockout clones. Microscopic analysis revealed distinctively different cell morphology of GluIIβ knockout cells with lesser cytoplasmic and cell surface area compared to parental A549 cells and non-targeted transfected cells.Further investigations revealed that Jurkat E6.1 T cells or human peripheral blood mononuclear cells (PBMCs) co-cultured with GluIIß knockout A549 exhibited significantly increased viability and tumor cell killing activity compared to those co-cultured with non-target transfected cells. Analysis of cytokine released from Jurkat E6.1 T cells co-cultured with GluIIß knockout A549 cells showed significant increased level of angiogenin and significant decreased level of ENA-78. In conclusion, knockout of GluIIß from cancer cells induced altered gene expression profile that improved anti-tumor activities of co-cultured T lymphocytes and PBMCs thus suppression of GluIIß may represent a novel approach of boosting anti-tumor immunity.

Peptide-based self-assembled monolayers (SAMs): what peptides can do for SAMs and vice versa.

Self-assembled monolayers (SAMs) represent highly ordered molecular materials with versatile biochemical features and multidisciplinary applications. Research on SAMs has made much progress since the early begginings of Au substrates and alkanethiols, and numerous examples of peptide-displaying SAMs can be found in the literature. Peptides, presenting increasing structural complexity, stimuli-responsiveness, and biological relevance, represent versatile functional components in SAMs-based platforms. This review examines the major findings and progress made on the use of peptide building blocks displayed as part of SAMs with specific functions, such as selective cell adhesion, migration and differentiation, biomolecular binding, advanced biosensing, molecular electronics, antimicrobial, osteointegrative and antifouling surfaces, among others. Peptide selection and design, functionalisation strategies, as well as structural and functional characteristics from selected examples are discussed. Additionally, advanced fabrication methods for dynamic peptide spatiotemporal presentation are presented, as well as a number of characterisation techniques. All together, these features and approaches enable the preparation and use of increasingly complex peptide-based SAMs to mimic and study biological processes, and provide convergent platforms for high throughput screening discovery and validation of promising therapeutics and technologies.

Cascade Reaction of Thiol-Disulfide Exchange Potentiates Rapid Fabrication of Polymer Hydrogels.

We report a rapid cross-linking strategy for the fabrication of polymer hydrogels based on a thiol-disulfide cascade reaction. Specifically, thiolated polymers (e.g., poly(ethylene glycol), hyaluronic acid, sodium alginate, poly(acrylic acid), and poly(methylacrylic acid)) can be cross-linked via the trigger of Ellman's reagent, resulting in the rapid formation of hydrogels over 20-fold faster than that via the oxidation in air. The gelation kinetics of hydrogels can be tuned by varying the polymer concentration and the molar ratio of Ellman's reagent and free thiols. The obtained hydrogels can be further functionalized with functional moieties (e.g., targeting ligands) for the selective adhesion of cells. This approach is applicable to various natural and synthetic polymers for the assembly of hydrogels with a minimized gelation time, which is promising for various biological applications.

Abstract 635: ESAM Deficiency-related Coronary Microvascular Dysfunction Contributes To Left Ventricle Diastolic Dysfunction In HFpEF

Coronary microvascular dysfunction and vascular inflammation have been linked to heart failure with preserved ejection fraction (HFpEF), but the underlying molecular mechanisms remain incompletely understood. Endothelial cell-selective adhesion molecule (ESAM) has been recently implicated as one of the biomarkers for heart failure. The biological function of ESAM is to regulate inflammatory cell adhesion, permeability and angiogenesis. Here, we examined the mechanistic role of ESAM in contributing left ventricle (LV) diastolic dysfunction in a mouse model of human HFpEF. We employed wild type (WT) mice and mice with homozygous genetic deficiency of ESAM (ESAM -/- ), with or without uninephrectomy and aldosterone infusion (UNX-Aldo, for 4-week). Using echocardiography, we found that WT mice with UNX-Aldo develop LV diastolic dysfunction, as indicated by a significantly reduced E/A ratio (E=early, A=late mitral inflow peak velocities), increased E/e’ ratio, isovolumic relaxation time (IVRT) and E wave deceleration time. UNX-Aldo significantly increased the serum soluble ESAM levels, along with elevated MMP2/9 levels, as potential mediators of ESAM ectodomain shedding. When compared to WT, ESAM -/- mice with UNX-Aldo displayed significant worsening of LV diastolic dysfunction, as indicated by increased IVRT, and the development of pulmonary edema and fibrosis. An unbiased automated tracing and 3D reconstruction of coronary microvasculature revealed that ESAM -/- mice had a significantly reduced coronary microvascular density. Arteries of ESAM -/- mice exhibited impaired endothelial sprouting and in cultured endothelial cells siRNA-mediated ESAM knockdown reduced tube formation. Thus, we propose that ESAM plays a role in the proper myocardial vascularization, hence the maintenance of myocardial perfusion. Deficiency, or augmented ectodomain shedding of ESAM impairs myocardial vascularization, whereby it contributes to the development of LV diastolic dysfunction, and could have mechanistic and diagnostic implications in human HFpEF.

Antigen loaded monocytes prime CD4+ T cell responses through Notch2 dependent cDC2

Abstract Cellular vaccines, primarily monocyte-derived dendritic cells (MoDC), have recently been realized as therapeutic cancer vaccines with modest clinical efficacy. Understanding the mechanism by which these vaccines lead to antigen presentation is key to improving their potency. A significant advancement was the discovery that MoDC vaccines do not directly present antigen, but instead rely on endogenous dendritic cells for their antigen presenting cell (APC) function. Subsequent research has also demonstrated that primary monocytes can be loaded with antigen and used as cellular vaccines, outperforming MoDC vaccines in mouse models of melanoma and glioblastoma. In this study, we characterized how monocyte vaccines generate CD4+ T cell responses. We utilized the CD11c-Cre RBPJfl/flmouse model, which lack a subset of Notch2 dependent cDC2 characterized by expression of Endothelial cell-selective adhesion molecule (ESAM hi). We demonstrate that the ESAM hicDC2 subset is required for effective CD4+ OT-II T cell priming after vaccination with ovalbumin (OVA) loaded monocytes. Interestingly, depletion of the ESAM hiDC population does not affect monocyte vaccine-induced CD8+ T cell priming, a process previously shown to be dependent on cDC1. This indicates that monocyte vaccines generate T cell responses by independently transferring antigen to both ESAM hiand CD8+ DCs, leveraging their APC function to prime CD4+ and CD8+ T cell responses, respectively. This work furthers the mechanistic understanding of monocyte vaccines, and will inform the design of future monocyte vaccines as they enter clinical trials as therapeutic cancer vaccines. Supported by NCI P50 CA 190991 and funding from the Stead Scholarship Program of the Duke University Department of Medicine.

Endothelial Cell-Selective Adhesion Molecule Enhances Tumor Growth in a HFpEF Mouse Model

Accumulating epidemiological evidence shows that the incidence of multiple types of cancer, such as melanoma and GI cancers, is significantly higher in patients with heart failure with preserved ejection fraction (HFpEF). However, the mechanistic relationships between HFpEF and cancer development are poorly understood. Impaired angiogenesis, upregulation of endothelial adhesion molecules and chronic low-grade inflammation are common in HFpEF. Here we examined the role of endothelial cell-selective adhesion molecule (ESAM) in the progression of malignant melanoma in a HFpEF mouse model. Orthotopic melanoma xenografts (B16F10-Luc2) were used and implanted subcutaneously in mice underwent uninephrectomy and aldosterone infusion (UNX-Aldo with 1% high salt drinking water for 4 weeks) and tumor growth was monitored with bioluminescent imaging. We found that ESAM expression and serum levels were elevated in the UNX-Aldo mice, which was accompanied by enhanced melanoma growth and metastasis rate. ESAM promoted tube formation and increased phospho-Akt, phospho-PKCα and phospho-ERK1/2 in cultured endothelial cells. Flow cytometry analysis showed elevated number of tumor-associated neutrophils (CD11b+Ly6G+Ly6C-) and myeloid-derived suppressor cells (MDSCs, CD11b+F4/80-Gr-1+) in the UNX-Aldo mice. UNX-Aldo mice with genetic deletion of ESAM (ESAM KO) showed a reduced tumor growth and reduced number of tumor-associated neutrophils and MDSCs. Collectively, our results indicate that in HFpEF, a proinflammatory ESAM activation may act to promote tumor angiogenesis, neutrophil and MDSCs tumor infiltration, thereby mitigating a proper immune response and facilitate tumor growth. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Mice with endothelial cell-selective adhesion molecule deficiency develop coronary microvascular rarefaction and left ventricle diastolic dysfunction.

Endothelial cell-selective adhesion molecule (ESAM) regulates inflammatory cell adhesion and transmigration and promotes angiogenesis. Here, we examined the role of ESAM in cardiac vascularization, inflammatory cell infiltration, and left ventricle (LV) diastolic function under basal and hemodynamic stress conditions. We employed mice with homozygous genetic deletion of ESAM (ESAM-/- ) and also performed uninephrectomy and aldosterone infusion (UNX-Aldo) to induce volume and pressure overload. Using echocardiography, we found that ESAM-/- mice display no change in systolic function. However, they develop LV diastolic dysfunction, as indicated by a significantly reduced E/A ratio (E=early, A=late mitral inflow peak velocities), increased E/e' ratio, isovolumic relaxation time (IVRT), and E wave deceleration time. An unbiased automated tracing and 3D reconstruction of coronary vasculature revealed that ESAM-/- mice had reduced coronary vascular density. Arteries of ESAM-/- mice exhibited impaired endothelial sprouting and in cultured endothelial cells siRNA-mediated ESAM knockdown reduced tube formation. Changes in ESAM-/- mice were accompanied by elevated myocardial inflammatory cytokine and myeloperoxidase-positive neutrophil levels. Furthermore, UNX-Aldo procedure in wild type mice induced LV diastolic dysfunction, which was accompanied by significantly increased serum ESAM levels. When compared to wild types, ESAM-/- mice with UNX-Aldo displayed worsening of LV diastolic function, as indicated by increased IVRT and pulmonary edema. Thus, we propose that ESAM plays a mechanistic role in proper myocardial vascularization and the maintenance of LV diastolic function under basal and hemodynamic stress conditions.

Propionate regulates tight junction barrier by increasing endothelial-cell selective adhesion molecule in human intestinal Caco-2 cells

Regulation of the intestinal barrier is closely associated with intestinal microbial metabolism. This study investigated the role of propionate, a major short-chain fatty acid produced by intestinal microorganisms, in the regulation of the tight junction (TJ) barrier in human intestinal Caco-2 cells. Propionate strengthened TJ barrier integrity, as indicated by decreased permeability to macromolecules and increased transepithelial electrical resistance in Caco-2 cells. DNA microarray analysis revealed that propionate upregulated endothelial cell-selective adhesion molecule (ESAM), a TJ-associated protein, without any increase in other TJ proteins. The upregulation of ESAM was confirmed using quantitative reverse transcription-PCR, immunoblotting, and immunofluorescence analyses. Luciferase promoter analysis demonstrated that propionate induced the transcriptional activation of ESAM. The effects of propionate were sensitive to nilotinib inhibition of NR2C2. Overexpression of human ESAM (hESAM) in canine kidney epithelial MDCK-II cells lowered the permeability to macromolecules in a manner similar to that of propionate-treated Caco-2 cells. hESAM overexpression facilitated calcium-induced assembly of the TJ complex in MDCK-II cells. Taken together, propionate strengthened the intestinal TJ barrier by increasing ESAM levels in Caco-2 cells.

Selective Topography Directed Cell Adhesion on Spider Silk Surfaces

AbstractFor tissue engineering applications, guided cell interaction with a biomaterial surface is one essential feature since, in natural tissue, cells constantly interact with their extracellular matrix, which provides different topographical, mechanical and biochemical stimuli. Therefore, the introduction of topographical surface features is one promising approach to direct material‐cell interactions. In this study, maskless lithography and soft lithographic methods are used to produce recombinant spider silk films with size gradient patterns, including grooves, circles, squares, triangles, and stars, to enhance specific cell attachment. The influence of surface features on cell behavior is analyzed using eight different cell lines. It can be shown that surface indentations provide cellular attachment sites and guiding structures for restructuring, aligning, and adopting cell morphology, with a relation of cell to feature size for some of the cell lines investigated. Therefore, specific topographical surface modifications can be used to guide selective cell adhesion, allowing the generation of tissue‐specifically modified implant surfaces in the future.

Abstract 15421: Mice Deficient in Endothelial Cell-Selective Adhesion Molecule Display Coronary Microvascular Rarefaction and Left Ventricle Diastolic Dysfunction

Coronary microvascular dysfunction and chronic inflammation play a role in the development of left ventricular diastolic dysfunction (LVDD) in heart failure with preserved ejection fraction (HFpEF). Endothelial cell-selective adhesion molecule (ESAM) is part of the endothelial cell junction complex, which plays a role in the maintenance of cell barrier function, inflammatory cell transmigration and angiogenesis. Here, we examined the role of ESAM in affecting coronary microvascular density and left ventricle diastolic function by employing mice with genetic deletion of ESAM (ESAM -/- ). Using echocardiography, we found that ESAM -/- mice display LVDD, as indicated by a significantly (p<0.05) reduced E/A ratio (E=early, A=late mitral inflow peak velocities), increased E/e’ ratio, isovolumic relaxation time and E wave deceleration time, with no change in the ejection fraction. Using an unbiased, automated tracing and 3D reconstruction of microvascular network revealed that ESAM -/- mice have a reduced coronary microvascular density, which was accompanied by myocardial accumulation of myeloperoxidase-positive neutrophils and elevated myocardial levels of inflammatory cytokines and chemokines. ESAM -/- mice exhibited a reduced endothelial sprout formation in the carotid artery, whereas in cultured endothelial cells siRNA-mediated ESAM knockdown impaired tube formation. Thus, ESAM deficiency in mice leads to coronary microvascular rarefaction, which likely via a myocardial hypoperfusion-related neutrophil accumulation and inflammatory mediator production impairs LV diastolic function.

Enrichment of Cancer Cells Based on Antibody-Free Selective Cell Adhesion.

Blood-compatible and cell-adhering polymer materials are extremely useful for regenerative medicine and disease diagnosis. (Meth)acryl polymers with high hydrophilicity have been widely used in industries, and attempts to apply these polymers in the medical field are frequently reported. We focused on crosslinked polymer films prepared using bifunctional monomers, which are widely used as coating materials, and attempted to alter the cell adhesion behavior while maintaining blood compatibility by changing the chemical structure of the crosslinker. Four bifunctional monomers were studied, three of which were found to be blood-compatible polymers and to suppress platelet adhesion. The adhesion behavior of cancer cells to polymer films varied; moreover, the cancer model cells MCF-7 [EpCAM(+)] and MDA-MB-231 [EpCAM (-)], with different expression levels of epithelial cell adhesion molecule (EpCAM), showed distinct adhesion behavior for each material. We suggest that a combination of these materials has the potential to selectively capture and enrich highly metastatic cancer cells.

Surface Modification of Polytetrafluoroethylene and Polycaprolactone Promoting Cell-Selective Adhesion and Growth of Valvular Interstitial Cells.

Tissue engineering concepts, which are concerned with the attachment and growth of specific cell types, frequently employ immobilized ligands that interact preferentially with cell types of interest. Creating multicellular grafts such as heart valves calls for scaffolds with spatial control over the different cells involved. Cardiac heart valves are mainly constituted out of two cell types, endothelial cells and valvular interstitial cells. To have control over where which cell type can be attracted would enable targeted cell settlement and growth contributing to the first step of an engineered construct. For endothelial cells, constituting the outer lining of the valve tissue, several specific peptide ligands have been described. Valvular interstitial cells, representing the bulk of the leaflet, have not been investigated in this regard. Two receptors, the integrin α9β1 and CD44, are known to be highly expressed on valvular interstitial cells. Here, we demonstrate that by covalently grafting the corresponding peptide and polysaccharide ligand onto an erodible, polycaprolactone (PCL), and a non-degradable, polytetrafluoroethylene (PTFE), polymer, surfaces were generated that strongly support valvular interstitial cell colonization with minimal endothelial cell and reduced platelet adhesion. The technology for covalent binding of corresponding ligands is a key element towards tissue engineered cardiac valves for in vitro applications, but also towards future in vivo application, especially in combination with degradable scaffold material.

Mice Deficient in Endothelial Cell‐Selective Adhesion Molecule Develop Vascular Endothelial and Left Ventricle Diastolic Dysfunction

The Endothelial Cell‐Selective Adhesion Molecule (ESAM) mediates inflammatory cell transmigration and also involved in pathological angiogenesis. Here we investigated the role of ESAM in affecting vasodilator and cardiac contractile function. To that end ESAM knockout and wild type (WT) mice were employed. Using transthoracic echocardiography it was found that ESAM knockout mice displayed left ventricle (LV) diastolic dysfunction, as indicated by a significantly reduced E/A ratio (E=early, A=late mitral inflow peak velocities), increased E/e’ ratio, isovolumic relaxation time (IVRT) and E wave deceleration time, with no change in the ejection fraction. The systolic blood pressure, as measured by tail‐cuff plethysmography, was not different between ESAM knockout and WT mice, whereas the heart to body weight ratio is increased in ESAM knockout mice. Using an unbiased automated tracing of the microvasculature we found a decreased vascularization (total vascular length) of the myocardium in ESAM knockout mice. In addition, vasodilator function of the pulmonary artery and aorta was assessed using wire myography. We found that the endothelium‐dependent, acetylcholine‐induced relaxation of the pulmonary artery was significantly reduced in ESAM knockout mice, whereas endothelium‐independent, sodium nitroprusside‐induced relaxation was similar in two groups. Thus, we conclude that ESAM deficiency causes vasodilator dysfunction, impaired angiogenesis underlying the development LV diastolic dysfunction.

Dntt expression reveals developmental hierarchy and lineage specification of hematopoietic progenitors.

Abstract Intrinsic and extrinsic cues determine developmental trajectories of hematopoietic stem cells (HSCs) towards erythroid, myeloid and lymphoid lineages. To dissect early lymphoid specification events, we generated two transgenic mouse models reporting and tracing the expression of terminal deoxynucleotidyl transferase (TdT). Surprisingly, transient induction of TdT was detected on a newly identified multipotent progenitor (MPP) subset which lacked self-renewal capacity but maintained multilineage differentiation potential. TdT induction by MPPs reflected a transcriptionally dynamic but uncommitted stage characterized by low expression of lineage-associated genes. Further, analysis using single-cell CITE-Seq indicated that multipotency is associated with expression of Endothelial Cell-Selective Adhesion Molecule (ESAM). Developmental progression along all lineages is defined by downregulation of ESAM and by stable TdT expression within the lymphoid trajectory. Collectively, we propose a new developmental hierarchy of early hematopoietic progenitors for which we provide their transcriptional profile as well as their phenotypic and functional properties at single cell resolution. Supported by NIH intramural funding

3D Visualization of Human Blood Vascular Networks Using Single-Domain Antibodies Directed against Endothelial Cell-Selective Adhesion Molecule (ESAM).

High-quality three-dimensional (3D) microscopy allows detailed, unrestricted and non-destructive imaging of entire volumetric tissue specimens and can therefore increase the diagnostic accuracy of histopathological tissue analysis. However, commonly used IgG antibodies are oftentimes not applicable to 3D imaging, due to their relatively large size and consequently inadequate tissue penetration and penetration speed. The lack of suitable reagents for 3D histopathology can be overcome by an emerging class of single-domain antibodies, referred to as nanobodies (Nbs), which can facilitate rapid and superior 2D and 3D histological stainings. Here, we report the generation and experimental validation of Nbs directed against the human endothelial cell-selective adhesion molecule (hESAM), which enables spatial visualization of blood vascular networks in whole-mount 3D imaging. After analysis of Nb binding properties and quality, selected Nb clones were validated in 2D and 3D imaging approaches, demonstrating comparable staining qualities to commercially available hESAM antibodies in 2D, as well as rapid and complete staining of entire specimens in 3D. We propose that the presented hESAM-Nbs can serve as novel blood vessel markers in academic research and can potentially improve 3D histopathological diagnostics of entire human tissue specimens, leading to improved treatment and superior patient outcomes.