Cell Contact Research Articles

Three-Dimensional Breast Cancer Model to Investigate CCL5/CCR1 Expression Mediated by Direct Contact between Breast Cancer Cells and Adipose-Derived Stromal Cells or Adipocytes.

The tumor microenvironment (TME) in breast cancer is determined by the complex crosstalk of cancer cells with adipose tissue-inherent cells such as adipose-derived stromal cells (ASCs) and adipocytes resulting from the local invasion of tumor cells in the mammary fat pad. This leads to heterotypic cellular contacts between these cell types. To adequately mimic the specific cell-to-cell interaction in an in vivo-like 3D environment, we developed a direct co-culture spheroid model using ASCs or differentiated adipocytes in combination with MDA-MB-231 or MCF-7 breast carcinoma cells. Co-spheroids were generated in a well-defined and reproducible manner in a high-throughput process. We compared the expression of the tumor-promoting chemokine CCL5 and its cognate receptors in these co-spheroids to indirect and direct standard 2D co-cultures. A marked up-regulation of CCL5 and in particular the receptor CCR1 with strict dependence on cell-cell contacts and culture dimensionality was evident. Furthermore, the impact of direct contacts between ASCs and tumor cells and the involvement of CCR1 in promoting tumor cell migration were demonstrated. Overall, these results show the importance of direct 3D co-culture models to better represent the complex tumor-stroma interaction in a tissue-like context. The unveiling of tumor-specific markers that are up-regulated upon direct cell-cell contact with neighboring stromal cells, as demonstrated in the 3D co-culture spheroids, may represent a promising strategy to find new targets for the diagnosis and treatment of invasive breast cancer.

Excessive sodium chloride ingestion promotes inflammation and kidney fibrosis in aging mice.

In aging kidneys, a decline of function resulting from extracellular matrix (ECM) deposition and organ fibrosis is regarded as "physiological." Whether a direct link between high salt intake and fibrosis in aging kidney exists autonomously from arterial hypertension is unclear. This study explores kidney intrinsic changes (inflammation, ECM derangement) induced by a high-salt diet (HSD) in a murine model lacking arterial hypertension. The contribution of cold shock Y-box binding protein (YB-1) as a key orchestrator of organ fibrosis to the observed differences is determined by comparison with a knockout strain (Ybx1ΔRosaERT+TX). Comparisons of tissue from mice fed with normal-salt diet (NSD, standard chow) or high-salt diet (HSD, 4% NaCl in chow; 1% NaCl in water) for up to 16 mo revealed that with HSD tubular cell numbers decrease and tubulointerstitial scarring [periodic acid-Schiff (PAS), Masson's trichrome, Sirius red staining] prevails. In Ybx1ΔRosaERT+TX animals tubular cell damage, a loss of cell contacts with profound tubulointerstitial alterations, and tubular cell senescence was seen. A distinct tubulointerstitial distribution of fibrinogen, collagen type VI, and tenascin-C was detected under HSD, transcriptome analyses determined patterns of matrisome regulation. Temporal increase of immune cell infiltration was seen under HSD of wild type, but not Ybx1ΔRosaERT+TX animals. In vitro Ybx1ΔRosaERT+TX bone marrow-derived macrophages exhibited a defect in polarization (IL-4/IL-13) and abrogated response to sodium chloride. Taken together, HSD promotes progressive kidney fibrosis with premature cell aging, ECM deposition, and immune cell recruitment that is exacerbated in Ybx1ΔRosaERT+TX animals.NEW & NOTEWORTHY Short-term experimental studies link excessive sodium ingestion with extracellular matrix accumulation and inflammatory cell recruitment, yet long-term data are scarce. Our findings with a high-salt diet over 16 mo in aging mice pinpoints to a decisive tipping point after 12 mo with tubular stress response, skewed matrisome transcriptome, and immune cell infiltration. Cell senescence was aggravated in knockout animals for cold shock Y-box binding protein (YB-1), suggesting a novel protective protein function.

Influence of titanium and zirconia substrates on the synthesis of inflammatory mediators.

The repair and homeostasis of peri-implant tissues depend on several factors such as the local presence of pathogenic bacteria and their products. Among other events, peri-implant tissue response is also related to the implant material used, which interferes with cells and extracellular matrix interactions, affecting the osseointegration process. In this study, the influence of zirconia (Zr) and titanium (Ti) substrates on the response of preosteoblasts (MC3T3) and murine macrophages (RAW 264.7) exposed to lipopolysaccharide (LPS, P. gingivalis) was evaluated. Zr and Ti disks were obtained and subjected to surface roughness standardization, which was analyzed by scanning electronic microscopy (SEM). The cells were subsequently cultured on Zr and Ti surfaces in AlphaMEM culture medium for 24 h, followed by LPS stimulus for 4 h. The production of reactive oxygen species (ROS) and gene expression of inflammatory markers were determined. SEM images showed that Ti disks exhibited higher surface roughness than that of Zr disks. Cells that seeded onto Ti and Zr had increased expression of inflammatory mediators and ROS production in the presence of LPS; however, such cell responses were more evident for Ti disks. These data indicate that contact of cells with Zr surfaces may lead to a lower inflammatory potential than Ti surfaces. Elucidation of the inflammatory response triggered by LPS for cells in contact with titanium and zirconia may contribute to the selection of materials for installation of osseointegrated implants.

Immune Function оf the Lymphatic System

Abstract—The lymphatic system plays a critical role in immunity, going far beyond the simple transport of immune cells and antigens. The endothelial cells in the various parts of this vasculature are highly specialized to perform various specific functions. Lymphatic capillaries express chemokines and adhesion molecules that in tissues promote the recruitment and transmigration of immune cells. Signaling molecules produced by endothelial cells of lymphatic capillaries during inflammation modulate the migration of lymphocytes through venules with high endothelium from the blood into the parenchyma of lymph nodes. Lymphatic vessels provide active regulated transport of immune cells and antigens to the lymph nodes. In the lymph nodes, with their complex structure organized by stromal cells, optimal conditions are created for the contacts of antigen-presenting cells with lymphocytes. Different subpopulations of lymph node endothelial cells perform specific functions according to lymph node location and contribute to both innate and adaptive immune responses through antigen presentation, lymph node remodeling, and regulation of leukocyte entry and exit.

Monolith Cs1-xRbxSnI3 perovskite – silicon 2T tandem solar cell using SCAPS-1D

Tandem solar cells (TSCs) have gained notoriety by the use of various absorber layers with different bandgaps. The photovoltaic characteristics of Cs1-xRbxSnI3 perovskite – silicon TSCs were determined through simulation using the SCAPS-1D software in this work by first validating the experimentally obtained efficiency of 2.08% for ITO/Cs0.8Rb0.2SnI3/PCBM/BCP/Al structure. The influence of chlorinated and undoped ITO front contact, variation of Electron Transport Layer (ETL) thickness, doping concentration, CBO and variation of absorber layer thickness, defect density, and doping concentration was studied. Optimum VOC (0.9893 V), JSC (30.04 mA/cm2), fill factor (81.78 %) and efficiency (24.31 %) were determined. The bottom cell was simulated independently with reference to experimental data using the structure Al/c-Si (n)/c-Si (p)/c-Si (p + )/Au resulting in an efficiency of 26.68 %. The monolithic Cs0.8Rb0.2SnI3 perovskite – silicon tandem solar cell of the architecture ITO/Cs0.8Rb0.2SnI3/c-Si (n)/c-Si (p)/c-Si (p + )/Au performance was analyzed by varying the thickness, doping concentration, and defect density of the active layers. Optimized parameters obtained were as follows: top perovskite layer thickness (100 nm), doping concentrations (5 × 1019 cm-3) and defect density (1 × 1013 cm-3), and bottom silicon absorber layer thickness (50 μm), doping concentrations (5 × 1016 cm-3), defect density (1 × 1012 cm-3), and a work function of 5.3 eV with chlorinated ITO as the front contact of the tandem cell. Optimized outcomes of efficiency (29.82 %), VOC (0.7992 V), JSC density (43.39 mA/cm2), and fill factor (85.98 %) were realized for the 2T Cs0.8Rb0.2SnI3 perovskite – silicon tandem solar cell.

α-catenin interaction with YAP/FoxM1/TEAD-induced CEP55 supports liver cancer cell migration

BackgroundAdherens junctions (AJs) facilitate cell–cell contact and contribute to cellular communication as well as signaling under physiological and pathological conditions. Aberrant expression of AJ proteins is frequently observed in human cancers; however, how these factors contribute to tumorigenesis is poorly understood. In addition, for some factors such as α‐catenin contradicting data has been described. In this study we aim to decipher how the AJ constituent α‐catenin contributes to liver cancer formation.MethodsTCGA data was used to detect transcript changes in 23 human tumor types. For the detection of proteins, liver cancer tissue microarrays were analyzed by immunohistochemistry. Liver cancer cell lines (HLF, Hep3B, HepG2) were used for viability, proliferation, and migration analyses after RNAinterference-mediated gene silencing. To investigate the tumor initiating potential, vectors coding for α‐catenin and myristoylated AKT were injected in mice by hydrodynamic gene delivery. A BioID assay combined with mass spectrometry was performed to identify α‐catenin binding partners. Results were confirmed by proximity ligation and co-immunoprecipitation assays. Binding of transcriptional regulators at gene promoters was investigated using chromatin-immunoprecipitation.Resultsα‐catenin mRNA was significantly reduced in many human malignancies (e.g., colon adenocarcinoma). In contrast, elevated α‐catenin expression in other cancer entities was associated with poor clinical outcome (e.g., for hepatocellular carcinoma; HCC). In HCC cells, α‐catenin was detectable at the membrane as well as cytoplasm where it supported tumor cell proliferation and migration. In vivo, α‐catenin facilitated moderate oncogenic properties in conjunction with AKT overexpression. Cytokinesis regulator centrosomal protein 55 (CEP55) was identified as a novel α‐catenin-binding protein in the cytoplasm of HCC cells. The physical interaction between α‐catenin and CEP55 was associated with CEP55 stabilization. CEP55 was highly expressed in human HCC tissues and its overexpression correlated with poor overall survival and cancer recurrence. Next to the α‐catenin-dependent protein stabilization, CEP55 was transcriptionally induced by a complex consisting of TEA domain transcription factors (TEADs), forkhead box M1 (FoxM1), and yes-associated protein (YAP). Surprisingly, CEP55 did not affect HCC cell proliferation but significantly supported migration in conjunction with α‐catenin.ConclusionMigration-supporting CEP55 is induced by two independent mechanisms in HCC cells: stabilization through interaction with the AJ protein α‐catenin and transcriptional activation via the FoxM1/TEAD/YAP complex.

The Life Cycle of Aurelia aurita Depends on the Presence of a Microbiome in Polyps Prior to Onset of Strobilation.

Aurelia aurita's intricate life cycle alternates between benthic polyp and pelagic medusa stages. The strobilation process, a critical asexual reproduction mechanism in this jellyfish, is severely compromised in the absence of the natural polyp microbiome, with limited production and release of ephyrae. Yet, the recolonization of sterile polyps with a native polyp microbiome can correct this defect. Here, we investigated the precise timing necessary for recolonization as well as the host-associated molecular processes involved. We deciphered that a natural microbiota had to be present in polyps prior to the onset of strobilation to ensure normal asexual reproduction and a successful polyp-to-medusa transition. Providing the native microbiota to sterile polyps after the onset of strobilation failed to restore the normal strobilation process. The absence of a microbiome was associated with decreased transcription of developmental and strobilation genes as monitored by reverse transcription-quantitative PCR. Transcription of these genes was exclusively observed for native polyps and sterile polyps that were recolonized before the initiation of strobilation. We further propose that direct cell contact between the host and its associated bacteria is required for the normal production of offspring. Overall, our findings indicate that the presence of a native microbiome at the polyp stage prior to the onset of strobilation is essential to ensure a normal polyp-to-medusa transition. IMPORTANCE All multicellular organisms are associated with microorganisms that play fundamental roles in the health and fitness of the host. Notably, the native microbiome of the Cnidarian Aurelia aurita is crucial for the asexual reproduction by strobilation. Sterile polyps display malformed strobilae and a halt of ephyrae release, which is restored by recolonizing sterile polyps with a native microbiota. Despite that, little is known about the microbial impact on the strobilation process's timing and molecular consequences. The present study shows that A. aurita's life cycle depends on the presence of the native microbiome at the polyp stage prior to the onset of strobilation to ensure the polyp-to-medusa transition. Moreover, sterile individuals correlate with reduced transcription levels of developmental and strobilation genes, evidencing the microbiome's impact on strobilation on the molecular level. Transcription of strobilation genes was exclusively detected in native polyps and those recolonized before initiating strobilation, suggesting microbiota-dependent gene regulation.

The Tumor Suppressor DAB2IP Is Regulated by Cell Contact and Contributes to YAP/TAZ Inhibition in Confluent Cells.

External and internal mechanical forces modulate cell morphology, movement, proliferation and metabolism, and represent crucial inputs for tissue homeostasis. The transcriptional regulators YAP and TAZ are important effectors of mechanical signaling and are frequently activated in solid tumors, correlating with metastasis, chemoresistance, and shorter patient survival. YAP/TAZ activity is controlled by various pathways that sense cell shape, polarity, contacts, and mechanical tension. In tumors, aberrant YAP/TAZ activation may result from cancer-related alterations of such regulatory networks. The tumor suppressor DAB2IP is a Ras-GAP and scaffold protein that negatively modulates multiple oncogenic pathways and is frequently downregulated or inactivated in solid tumors. Here, we provide evidence that DAB2IP expression is sustained by cell confluency. We also find that DAB2IP depletion in confluent cells alters their morphology, reducing cell packing while increasing cell stiffness. Finally, we find that DAB2IP depletion in confluent cells favors YAP/TAZ nuclear localization and transcriptional activity, while its ectopic expression in subconfluent cells increases YAP/TAZ retention in the cytoplasm. Together, these data suggest that DAB2IP may function as a sensor of cell interactions, contributing to dampening cellular responses to oncogenic inputs in confluent cells and that DAB2IP loss-of-function would facilitate YAP/TAZ activation in intact epithelia, accelerating oncogenic transformation.

The Rap1 small GTPase affects cell fate or survival and morphogenetic patterning during Drosophila melanogaster eye development

The Drosophila melanogaster eye has been instrumental for determining both how cells communicate with one another to determine cell fate, as well as cell morphogenesis and patterning. Here, we describe the effects of the small GTPase Rap1 on the development of multiple cell types in the D. melanogaster eye. Although Rap1 has previously been linked to RTK-Ras-MAPK signaling in eye development, we demonstrate that manipulation of Rap1 activity is modified by increase or decrease of Delta/Notch signaling during several events of cell fate specification in eye development. In addition, we demonstrate that manipulating Rap1 function either in primary pigment cells or in interommatidial cells affects cone cell contact switching, primary pigment cell enwrapment of the ommatidial cluster, and sorting of secondary and tertiary pigment cells. These data suggest that Rap1 has roles in both ommatidial cell recruitment/survival and in ommatidial morphogenesis in the pupal stage. They lay groundwork for future experiments on the role of Rap1 in these events.

Building the synapse engine to drive B lymphocyte function

B cell receptor (BCR)-mediated antigen-specific recognition activates B lymphocytes and drives the humoral immune response. This enables the generation of antibody-producing plasma cells, the effector arm of the B cell immune response, and of memory B cells, which confer protection against additional encounters with antigen. B cells search for cognate antigen in the complex cellular microarchitecture of secondary lymphoid organs, where antigens are captured and exposed on the surface of different immune cells. While scanning the cell network, the BCR can be stimulated by a specific antigen and elicit the establishment of the immune synapse with the antigen-presenting cell. At the immune synapse, an integrin-enriched supramolecular domain is assembled at the periphery of the B cell contact with the antigen-presenting cell, ensuring a stable and long-lasting interaction. The coordinated action of the actomyosin cytoskeleton and the microtubule network in the inner B cell space provides a structural framework that integrates signaling events and antigen uptake through the generation of traction forces and organelle polarization. Accordingly, the B cell immune synapse can be envisioned as a temporal engine that drives the molecular mechanisms needed for successful B cell activation. Here, I review different aspects of the B cell synapse engine and provide insights into other aspects poorly known or virtually unexplored.

Alpha 7 nicotinic acetylcholine receptors signaling boosts cell-cell interactions in macrophages effecting anti-inflammatory and organ protection

Activation of the cholinergic anti-inflammatory pathway (CAP) via vagus nerve stimulation has been shown to improve acute kidney injury in rodent models. While alpha 7 nicotinic acetylcholine receptor (α7nAChR) positive macrophages are thought to play a crucial role in this pathway, their in vivo significance has not been fully understood. In this study, we used macrophage-specific α7nAChR-deficient mice to confirm the direct activation of α7nAChRs in macrophages. Our findings indicate that the administration of GTS-21, an α7nAChR-specific agonist, protects injured kidneys in wild-type mice but not in macrophage-specific α7nAChR-deficient mice. To investigate the signal changes or cell reconstructions induced by α7nAChR activation in splenocytes, we conducted single-cell RNA-sequencing of the spleen. Ligand-receptor analysis revealed an increase in macrophage-macrophage interactions. Using macrophage-derived cell lines, we demonstrated that GTS-21 increases cell contact, and that the contact between macrophages receiving α7nAChR signals leads to a reduction in TNF-α. Our results suggest that α7nAChR signaling increases macrophage-macrophage interactions in the spleen and has a protective effect on the kidneys.

P-291 Seeking Arrangements: A New Cleavage-Stage Biomarker from 3D Morphokinetics

Abstract Study question What can we learn from 3D reconstructions of cleavage-stage embryos derived from Hoffman modulation contrast (HMC) time-lapses? Summary answer A simple spatial biomarker extracted from 3D embryo reconstructions at the t4 and t8 stages is associated with blastulation, blastocyst quality, pregnancy and live birth. What is known already Several works have demonstrated significant associations between t4 cell arrangement and blastulation potential. However, no studies have investigated the impacts of cell arrangement beyond the t4 stage in a clinical setting owing to difficulties visualising the 3D structure of embryos in a safe, cost-effective manner. In the previous ESHRE meeting, He et al. presented a deep learning system for the 3D reconstruction of cleavage-stage embryos from HMC focal stacks recorded in standard timelapse incubators. In this work, we use the aforementioned system to understand the spatial networks present in cleavage-stage embryos and investigate their associations with clinical outcomes. Study design, size, duration The study was a retrospective analysis of two imaging datasets from two different clinics. The first dataset (DS1) consisted of 162 t4 embryos with information on blastulation and Gardner grade. The second dataset (DS2) consisted of 202 embryos at t4 and t8 with information on blastocyst grade, pregnancy, live birth and PGT-A. All data was captured at 11 focal planes on Embryoscope incubators between 2018 and 2020. Participants/materials, setting, methods The system proposed by He et al. was used to reconstruct the 3D structure of embryos from their focal stacks. Networks of cell contacts were extracted from the resulting embryo 3D models and each embryo’s mean contacts per cell was computed. Statistical analysis of average cell contacts with respect to outcomes was carried out using unpaired t-tests. Moreover, cell contact networks from different embryos were compared to identify embryos with similar cell arrangements. Main results and the role of chance At t4, a higher average number of contacts per cell was associated with greater rates of blastulation in DS1 (2.59 vs 2.36, blastulated vs non-blastulated, p = 0.029) and blastocyst quality in both DS1 (2.59 vs 2.37, good vs poor, p = 0.010) and DS2 (2.51 vs 2.35, good vs poor, p = 0.017) where a ‘good’ embryo is defined as having an embryologist-provided Gardner grade with EXP>2, ICM>C and TE>C. At t8, a higher average number of contacts was associated with increased blastocyst quality (3.36 vs 3.09, good vs poor, p = 0.017), pregnancy (3.32 vs 2.87, pregnant vs not pregnant, p = 0.003) and live birth (3.40 vs 2.90, live birth vs no live birth, p = 0.0003). No associations were found with miscarriage or aneuploidy. Moreover, average contacts at t4 were not correlated with those at t8 (r = 0.15, 95% CI [-0.043, 0.34]). While 4-cell embryos fell neatly into 9 distinct cell arrangements with the 5 most common (tetrahedral, pseudotetrahedral, planar, closed-Y and linear) accounting for 95% of embryos, 8-cell embryos displayed a great degree of variation with 59 distinct cell arrangements, the largest such group representing only 8 embryos. Limitations, reasons for caution The datasets used in this study were small. Moreover, DS2 was subject to survivorship bias as it only contained embryos with PGT-A results which necessarily entailed successful blastulation. Furthermore, the 3D reconstruction system was not applicable to all cleavage-stage embryos, especially those obscured by the well or having undergone compaction. Wider implications of the findings This work provides evidence for the clinical relevance of cleavage-stage cell arrangement in the human preimplantation embryo beyond the 4-cell stage, which may improve selection techniques for D3 transfers. Moreover, our work provides a strong case for further investigation into spatial biomarkers derived from 3D embryo reconstruction and 3D morphokinetics. Trial registration number N/A

O-189 Extracellular vesicles derived from human myometrial cells support endometrial mesenchymal stromal/stem cells

Abstract Study question Whether other forms of intercellular communication such as extracellular vesicles (EVs) participate in stem cell maintenance in the human endometrium. Summary answer The present study revealed the involvement of EVs as a novel intercellular communication method between endometrial mesenchymal stem cells (eMSC) and their surrounding niche. What is known already In human endometrium, many studies have demonstrated the importance of EVs in mediating various physiological as well as pathological processes. Our group has demonstrated that the myometrial cells are candidate niche cells of eMSC modulating their biological function. We also demonstrate the Notch signaling pathway is involved in endometrial stem cell regulation. Although classical Notch signaling relies on direct cell contact dependent interactions, this pathway can also be activated at a distance by EVs containing Notch ligands. Therefore, we hypothesized that certain Notch ligand(s) are packaged into the myometrial EVs to mediate stem cell functions. Study design, size, duration Sequential beading with magnetic beads coated with anti-CD140b and anti-CD146 antibodies was used to isolate eMSC (CD140b+CD146+ cells) from endometrial tissues from proliferative (n = 15) and secretory (n = 10) phase. Myometrial derived EVs (n = 17) were isolated by ultracentrifugation. The EVs were characterized by transmission electron microscopy and western blotting. Participants/materials, setting, methods Endometrial samples obtained from women aged 41 – 52 years undergoing total abdominal hysterectomy. EMSC were cocultured with myometrial EVs and the percentage of eMSC was analysed by flow cytometry. Blockage the secretion of EVs was performed by transfection of Rab27a siRNA. Western blot analysis and gene silencing approach validated the role of Notch signaling in eMSC. The therapeutic features of transplanted eMSC/myometrial EVs was determined using the mouse injured endometrial model. Main results and the role of chance EVs released from myometrial cells can be internalized by eMSC, leading to a significant effect on stemness of eMSC. Pharmacological inhibition of Notch signaling with DAPT or silencing of Notch 1 nullified these stimulatory effects. Myometrial EVs contains a high amount of the notch ligand – JAG1, thus inducing a strong Notch activity in eMSC. When JAG1 was silenced in the myometrial EVs, the self-renewal and clonogenic activity was reduced. Combined transplantation of eMSC with myometrial EVs improves the therapeutic effect of eMSC in endometrial regeneration in vivo. The observed therapeutic feature was potentially achieved by elevating the cell proliferation and suppressing apoptosis in the injured mouse endometrium. Limitations, reasons for caution Whether other signaling pathway are involved in the stimulatory effect of myometrial EVs in eMSC activities remains unknown. Also, EVs derived from other endometrial cell types i.e. epithelial cells may also regulate eMSC function. Wider implications of the findings Our findings revealed that myometrial EVs stimulated the biological function of eMSC via the Notch signaling. In the near future, it would be important to explore whether Notch signaling pathway plays a role in the injured mouse endometrium transplanted with eMSC/myometrial EVs. Trial registration number Not applicable

(Patho)Physiology of Glycosylphosphatidylinositol-Anchored Proteins II: Intercellular Transfer of Matter (Inheritance?) That Matters

Glycosylphosphatidylinositol (GPI)-anchored proteins (APs) are anchored at the outer leaflet of the plasma membrane (PM) bilayer by covalent linkage to a typical glycolipid and expressed in all eukaryotic organisms so far studied. Lipolytic release from PMs into extracellular compartments and intercellular transfer are regarded as the main (patho)physiological roles exerted by GPI-APs. The intercellular transfer of GPI-APs relies on the complete GPI anchor and is mediated by extracellular vesicles such as microvesicles and exosomes and lipid-free homo- or heteromeric aggregates, and lipoprotein-like particles such as prostasomes and surfactant-like particles, or lipid-containing micelle-like complexes. In mammalian organisms, non-vesicular transfer is controlled by the distance between donor and acceptor cells/tissues; intrinsic conditions such as age, metabolic state, and stress; extrinsic factors such as GPI-binding proteins; hormones such as insulin; and drugs such as anti-diabetic sulfonylureas. It proceeds either “directly” upon close neighborhood or contact of donor and acceptor cells or “indirectly” as a consequence of the induced lipolytic release of GPI-APs from PMs. Those displace from the serum GPI-binding proteins GPI-APs, which have retained the complete anchor, and become assembled in aggregates or micelle-like complexes. Importantly, intercellular transfer of GPI-APs has been shown to induce specific phenotypes such as stimulation of lipid and glycogen synthesis, in cultured human adipocytes, blood cells, and induced pluripotent stem cells. As a consequence, intercellular transfer of GPI-APs should be regarded as non-genetic inheritance of (acquired) features between somatic cells which is based on the biogenesis and transmission of matter such as GPI-APs and “membrane landscapes”, rather than the replication and transmission of information such as DNA. Its operation in mammalian organisms remains to be clarified.

Simultaneous induction of vasculature and neuronal network formation on a chip reveals a dynamic interrelationship between cell types

BackgroundNeuronal networks receive and deliver information to regulate bodily functions while the vascular network provides oxygen, nutrients, and signaling molecules to tissues. Neurovascular interactions are vital for both tissue development and maintaining homeostasis in adulthood; these two network systems align and reciprocally communicate with one another. Although communication between network systems has been acknowledged, the lack of relevant in vitro models has hindered research at the mechanistic level. For example, the current used in vitro neurovascular models are typically established to be short-term (≤ 7 days) culture models, and they miss the supporting vascular mural cells.MethodsIn this study, we utilized human induced pluripotent stem cell (hiPSC) -derived neurons, fluorescence tagged human umbilical vein endothelial cells (HUVECs), and either human bone marrow or adipose stem/stromal cells (BMSCs or ASCs) as the mural cell types to create a novel 3D neurovascular network-on-a-chip model. Collagen 1–fibrin matrix was used to establish long-term (≥ 14 days) 3D cell culture in a perfusable microphysiological environment.ResultsAprotinin-supplemented endothelial cell growth medium-2 (EGM-2) supported the simultaneous formation of neuronal networks, vascular structures, mural cell differentiation, and the stability of the 3D matrix. The formed neuronal and vascular networks were morphologically and functionally characterized. Neuronal networks supported vasculature formation based on direct cell contacts and by dramatically increasing the secretion of angiogenesis-related factors in multicultures in contrast to cocultures without neurons. Both utilized mural cell types supported the formation of neurovascular networks; however, the BMSCs seemed to boost neurovascular networks to greater extent.ConclusionsOverall, our study provides a novel human neurovascular network model that is applicable for creating in vivo-like tissue models with intrinsic neurovascular interactions. The 3D neurovascular network model on chip forms an initial platform for the development of vascularized and innervated organ-on-chip and further body-on-chip concepts and offers the possibility for mechanistic studies on neurovascular communication both under healthy and in disease conditions.DtMPMfM_nPvk_pFj8pUo8rVideo

Front-contact passivation through 2D/3D perovskite heterojunctions enables efficient bifacial perovskite/silicon tandem solar cells

•Non-uniform formation of n = 2 is more dominant for iso-BAI-passivated perovskite •Bifacial perovskite/Si tandem devices exhibited power generation density >27 mW cm−2 •Shorter spacer iso-BA reduced the charge accumulation at thinner quantum wells •Branched BA-based 2D perovskite formation resulted in JSC as high as 22.8 mA cm−2 Surface passivation by thin-slab 2D perovskites is an effective method to suppress interfacial carrier recombination of 3D metal halide perovskite photoabsorbers. However, improving device performance by integrating such 2D/3D perovskite heterojunctions in the sunward, transparent contacts of perovskite solar cells is not evident due to the high exciton binding energies of phase-pure 2D perovskites, which may result in inefficient free-carrier generation and collection. Here, we overcome this challenge by tuning the dimensionality of 2D perovskites via structural isomers of butylammonium (BA) as a small organic cation, occupying the A-site of the 2D perovskite lattice. The discontinuous iso-BA-based 2D crystals on the 3D perovskite surface yield improved interfacial passivation and enhanced hole extraction. Besides an increased open circuit voltage, this remarkably leads to an enhanced photocurrent (∼1 mA cm−2) compared with control perovskite solar cells, resulting in bifacial perovskite/silicon tandem solar cells with power generation densities >27 mW cm−2. Surface passivation by thin-slab 2D perovskites is an effective method to suppress interfacial carrier recombination of 3D metal halide perovskite photoabsorbers. However, improving device performance by integrating such 2D/3D perovskite heterojunctions in the sunward, transparent contacts of perovskite solar cells is not evident due to the high exciton binding energies of phase-pure 2D perovskites, which may result in inefficient free-carrier generation and collection. Here, we overcome this challenge by tuning the dimensionality of 2D perovskites via structural isomers of butylammonium (BA) as a small organic cation, occupying the A-site of the 2D perovskite lattice. The discontinuous iso-BA-based 2D crystals on the 3D perovskite surface yield improved interfacial passivation and enhanced hole extraction. Besides an increased open circuit voltage, this remarkably leads to an enhanced photocurrent (∼1 mA cm−2) compared with control perovskite solar cells, resulting in bifacial perovskite/silicon tandem solar cells with power generation densities >27 mW cm−2.

The effects of microcapsules with different protein matrixes on the viability of probiotics during spray drying, gastrointestinal digestion, thermal treatment, and storage

AbstractThe objective of this research was to encapsulate probiotic bacteria based on the protein matrix and investigate the influences on the survival of probiotic bacteria during spray drying, in vitro gastrointestinal digestion, heating, and storage. A probiotic isolate Bacillus coagulans BC01 was spray dried in whey protein isolate (WPI), soy protein isolate (SPI), camel whey protein isolate, or sodium caseinate. Probiotic microcapsules fabricated using WPI obtained the highest survival during spray drying, NaCl and paraxin challenges and storage, as less cell wall damage occurred during spray drying which could be observed by flow cytometer. However, the highest survivals during in vitro gastrointestinal digestion and thermal treatment were found in microcapsules with SPI matrix, which could be attributed to its relatively low solubility in water that prevented probiotics from being released prematurely, thus protecting probiotics from the damage of low pH environment and diminishing the direct contact of cells with external heat shock. In conclusion, the current study demonstrated that WPI‐based probiotic microcapsules with less cell wall damage during processing and SPI‐based probiotic microcapsules with relatively low solubility may provide better protection to adverse external environments.

Mechanical activation of lung epithelial cells through the ion channel Piezo1 activates the metalloproteinases ADAM10 and ADAM17 and promotes growth factor and adhesion molecule release

In the lung, pulmonary epithelial cells undergo mechanical stretching during ventilation. The associated cellular mechanoresponse is still poorly understood at the molecular level. Here, we demonstrate that activation of the mechanosensitive cation channel Piezo1 in a human epithelial cell line (H441) and in primary human lung epithelial cells induces the proteolytic activity of the metalloproteinases ADAM10 and ADAM17 at the plasma membrane. These ADAMs are known to convert cell surface expressed proteins into soluble and thereby play major roles in proliferation, barrier regulation and inflammation. We observed that chemical activation of Piezo1 promotes cleavage of substrates that are specific for either ADAM10 or ADAM17. Activation of Piezo1 also induced the synthesis and ADAM10/17-dependent release of the growth factor amphiregulin (AREG). In addition, junctional adhesion molecule A (JAM-A) was shed in an ADAM10/17-dependent manner resulting in a reduction of cell contacts. Stretching experiments combined with Piezo1 knockdown further demonstrated that mechanical activation promotes shedding via Piezo1. Most importantly, high pressure ventilation of murine lungs increased AREG and JAM-A release into the alveolar space, which was reduced by a Piezo1 inhibitor. Our study provides a novel link between stretch-induced Piezo1 activation and the activation of ADAM10 and ADAM17 in lung epithelium. This may help to understand acute respiratory distress syndrome (ARDS) which is induced by ventilation stress and goes along with perturbed epithelial permeability and release of growth factors.

Optimized Gingiva Cell Behavior on Dental Zirconia as a Result of Atmospheric Argon Plasma Activation.

Several physico-chemical modifications have been developed to improve cell contact with prosthetic oral implant surfaces. The activation with non-thermal plasmas was one option. Previous studies found that gingiva fibroblasts on laser-microstructured ceramics were hindered in their migration into cavities. However, after argon (Ar) plasma activation, the cells concentrated in and around the niches. The change in surface properties of zirconia and, subsequently, the effect on cell behavior is unclear. In this study, polished zirconia discs were activated by atmospheric pressure Ar plasma using the kINPen®09 jet for 1 min. Surfaces were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy (XPS), and water contact angle. In vitro studies with human gingival fibroblasts (HGF-1) focused on spreading, actin cytoskeleton organization, and calcium ion signaling within 24 h. After Ar plasma activation, surfaces were more hydrophilic. XPS revealed decreased carbon and increased oxygen, zirconia, and yttrium content after Ar plasma. The Ar plasma activation boosted the spreading (2 h), and HGF-1 cells formed strong actin filaments with pronounced lamellipodia. Interestingly, the cells' calcium ion signaling was also promoted. Therefore, argon plasma activation of zirconia seems to be a valuable tool to bioactivate the surface for optimal surface occupation by cells and active cell signaling.

Regulation of kisspeptin-54 activity of indolamine-2,3-dioxygenase and apoptosis of peripheral blood lymphocytes

Pregnancy is a phenomenon of natural semi-allogeneic transplantation, since the fetus is half alien due to the expression of paternal antigens. It was found that the hypothalamic hormone kisspeptin during pregnancy is produced by the syncytiotrophoblast of the placenta and participates in the formation of a new specific hormonal background. Several forms of the hormone circulate in the blood of pregnant women: kisspeptin-10, kisspeptin-14 and kisspeptin-54 (according to the number of amino acid residues in the hormone molecule), but the main active form is kisspeptin-54. The main mechanism for the formation of immune tolerance during pregnancy is the induction of the expression of the enzyme indolamine-2,3- dioxygenase (IDO) by antigen-presenting cells of peripheral blood, resulting in the catalysis of tryptophan (Trp) to kynurenins (KYN) blocking the activation and causing apoptosis of cytotoxic CD8+T lymphocytes in the zone of contact of maternal immune cells with placental-fetal complex antigens. In addition, during pregnancy, an important role is assigned to the process of apoptosis, since activated cells can be potentially dangerous for the developing fetus. Immunocompetent blood cells express a specific membrane receptor of kisspeptin (KISS-1R). Since kisspeptin-54 enters the systemic circulation only during pregnancy, the hormone has an effect on immune cells only during this period.The aim of this work was to evaluate the effect of kisspeptin-54 in concentrations comparable to its levelduring physiological pregnancy on IDO activity and apoptosis of peripheral blood lymphocytes.Peripheral blood mononuclear cells (PBMC) obtained from 10 healthy non-pregnant women of reproductive age (from 23 to 32 years) were used as the object of the study. Lymphocyte apoptosis was assessed in PBMC suspension by staining with annexin-V and propidium iodide. The determination of the number of cells in the early and late stages of apoptosis was carried out in the isolated gate of lymphocytes. IDO activity in PBMC was determined spectrophotometrically by changes in the concentration of KYN, the first stable metabolite of the Trp decay pathway.It was found that kisspeptin-54 at a concentration of 4.6 pM corresponding to the second trimester of pregnancy significantly enhances the activity of IDO, increases the number of cells in the early and late stages of apoptosis. Thus, kisspeptin-54 is an important mechanism for controlling these processes during pregnancy, aimed at protecting the semi-allogeneic fetus from adverse immune reactions of the mother and the favorable development of pregnancy.