Physiological State Of Cells Research Articles

Long-term cell culture and electrically in situ monitoring of living cells based on a polyaniline hydrogel sensor.

Accurate, in situ and long-term electrically monitoring of cell development plays an important role in cell study, which brings in challenges in terms of biocompatibility, processability, and sensing capability of electrochemical sensors. Based on biocompatible conductive polyaniline (PAni) hydrogels, we constructed a flexible sensor with flexible carbon cloth for electrical analysis of living cells. The carbon fiber substrate modified with conductive PAni hydrogels was selected as the electrode to promote the current collection of the sensor. The three dimensional nanostructured mesoporous matrix of PAni hydrogels is favorable for in situ generation of catalytic Pt nanoparticles and cell growth. With these hierarchically nanostructured features, the hydrogel electrochemical sensor was endowed with high sensitivity and selectivity in the detection of H2O2 (with a low detection limit of 1.6 μM in 0.01 M PBS and a wide linear range from 10 μM to 10 mM), and good biocompatibility for cell growth as long as 5 days. The accurate detection of H2O2 released from cells enabled us to differentiate the physiological states of cells and imitate the different stimuli-responsive behavior, which can provide real-time information on cell biological events. With outstanding biocompatibility, operability and repeatability, this strategy can be expanded to the fields of other biosensor fabrication and cell-related biomarker monitoring, which exhibits a broad application potential in bioanalysis catering to new generation sensors.

Research progress on effective components of Chinese materia medica in regulating autophagy

Autophagy is a highly conservative and multi-component activated energy metabolism and self-renewal mechanism, which plays a crucial regulatory role in maintaining the normal physiological state of cells and is involved in various pathological processes. In recent years, the mechanism study has made great progress in regulating autophagy with effective components of Chinese materia medica(CMM),which are reported to prevent and treat cancers, neurodegenerative diseases, cardiovascular diseases and metabolic and immune-related diseases. This review outlines the molecular regulation mechanisms of cell autophagy with CMM components in controlling the above-mentioned diseases. There are many relevant reports on the regulatory mechanisms of autophagy in tumor and cardiovascular cells with CMM monomers. The main chemical structural types are alkaloids, saponins, polyphenols, flavonoids and terpenes. And m-TOR pathway is the main mechanism relating to the regulatory mechanisms of autophagy with CMM. Therefore, the regulatory mec-hanisms of cell autophagy become a new research targeting strategy of therapies with CMM. This review provides evidences for the effectiveness and scientificity of CMM in regulating autophagy, in the expectation of providing references for the in-depth studies of CMM in the field of autophagy and the development of natural autophagy regulators.

Elasticity spectra as a tool to investigate actin cortex mechanics

BackgroundThe mechanical properties of single living cells have proven to be a powerful marker of the cell physiological state. The use of nanoindentation-based single cell force spectroscopy provided a wealth of information on the elasticity of cells, which is still largely to be exploited. The simplest model to describe cell mechanics is to treat them as a homogeneous elastic material and describe it in terms of the Young’s modulus. Beside its simplicity, this approach proved to be extremely informative, allowing to assess the potential of this physical indicator towards high throughput phenotyping in diagnostic and prognostic applications.ResultsHere we propose an extension of this analysis to explicitly account for the properties of the actin cortex. We present a method, the Elasticity Spectra, to calculate the apparent stiffness of the cell as a function of the indentation depth and we suggest a simple phenomenological approach to measure the thickness and stiffness of the actin cortex, in addition to the standard Young’s modulus.ConclusionsThe Elasticity Spectra approach is tested and validated on a set of cells treated with cytoskeleton-affecting drugs, showing the potential to extend the current representation of cell mechanics, without introducing a detailed and complex description of the intracellular structure.

Extracellular vesicles in spontaneous preterm birth.

Feto-maternal communication helps to maintain pregnancy and contributes to parturition at term and preterm. Endocrine and immune factor are well-reported communication mediators. Recent advances in extracellular vesicle (EV) biology have introduced them as major communication channels between the mother and fetus. EVs are round structures with a lipid bilayer membrane. EVs are generally categorized based on their size and mode of biogenesis. The most commonly reported EVs are exosomes with a size range of 30-160nm that are formed inside the intraluminal vesicles of multivesicular body. Microvesicles (MVs) are larger than>200nm and formed by outward budding of plasma membrane. Vesicles are released from all cells and carry various factors that reflect the physiologic state of cell at the time of their release. Analysis of vesicle provides a snapshot of origin cell. Recent studies in perinatal medicine have shown that exosomes are key communicators between feto-maternal units, and they can cross placenta. Fetal-derived exosomes released under term labor-associated conditions can cause parturition-associated changes in maternal uterine tissues. Exosomes carrying inflammatory cargo can cause preterm birth in animal models suggesting their functional role in parturition. A few reports have profiled differences between exosome cargos from term and preterm pregnancies and indicated their biomarker potential to predict high-risk pregnancy status. There are hardly any reports on MVs and their functional roles in reproduction. Herein, we review of EVs and MVs, their characteristics, function, and usefulness predicting adverse pregnancy complications such as preterm birth.

Short-term effect of cadmium on the motility of three flagellated algal species

The present work aims to develop a fast and reliable procedure for motility analysis of a short-term effect of heavy metal cadmium on the algal cell response in laboratory conditions. Three unicellular motile species similar in cell length, while differing in the cell wall and the flagellar system are used as model algae. We quantitatively characterise motility in terms of swimming speed and search radius following addition of 1 mg Cd L−1. Both swimming speed and search radius determined in control algal cultures reflect morphological features of the corresponding flagellated system. After 1 h of cell exposure to a toxic concentration of cadmium, a statistically significant decrease in swimming speed is determined with predominant erratic cell movement on the spot in all examined cultures. After 3 h of cell exposure to cadmium, swimming speed in most of the examined cell cultures recovered close to the control value, indicating quick cell adaptation to elevated cadmium concentration. The results support the implementation of swimming speed and search radius as motility parameters for direct screening of cell physiological state, which is applicable to ecotoxicological studies providing insight into the mechanism of cell adaptation under stress, as well as a better understanding of the spatial distribution of algal cells in aquatic systems.

Exosomes from different cells: Characteristics, modifications, and therapeutic applications.

Exosomes are cystic vesicles secreted by living cells with a phospholipid bilayer membrane. Importantly, these vesicles could serve to carry lipids, proteins, genetic materials, and transmit biological information invivo. The cell-specific proteins and genetic materials in exosomes are capable of reflecting their cell origin and physiological status. Based on the different tissues and cells (macrophage, dendritic cells, tumor cells, mesenchymal stem cells, various body fluids, and so on), exosomes exhibit different characteristics and functions. Furthermore, owing to their high delivery efficiency, biocompatibility, and multifunctional properties, exosomes are expected to become a new means of drug delivery, disease diagnosis, immunotherapy, and precise treatment. At the same time, in order to supplement or enhance the therapeutic applicability of exosomes, chemical or biological modifications can be used to broaden, change or improve their therapeutic capabilities. This review focuses on three aspects: the characteristics and original functions of exosomes secreted by different cells, the modification and transformation of exosomes, and the application of exosomes in different diseases.

Simultaneous monitoring of polarity changes of lipid droplets and lysosomes with two-photon fluorescent probes

Intracellular polarity is an essential feature of cell physiological state and abnormal polarity changes of various organelles are related to many diseases. Thus, monitoring of polarity changes of multiple subcellular in living cells contributes to understanding different physiological and pathological processes more accurately. However, most of the previous reports on polarity probes mainly monitored the polarity of a single organelle. Therefore, we designed and synthesized two unique polarity-sensitive fluorescent probes LDs-TPFP and Lyso-TPFP, which can be selectively located in lipid droplets (LDs) and lysosomes respectively, to obtain more subcellular information in living cells. Thanks to the strong intramolecular-charge-transfer (ICT) characteristics of probes, the fluorescence intensity and emission wavelength would change with the polarity of the surroundings of cells. Moreover, LDs-TPFP and Lyso-TPFP exhibits large Stokes shift and excellent biocompatibility. Through fluorescence imaging, the probes can effectively distinguish normal cells from cancer cells. In addition, the results of two-photon confocal fluorescence imaging indicated that LDs and lysosomes have discrepant polarity change behaviors under different physiological conditions.

Protein A-Mediated Binding ofStaphylococcusspp. to Antibodies in Flow Cytometric Assays and Reduction of This Binding by Using Fc Receptor Blocking Reagent

Staphylococcus aureus and other coagulase-positive Staphylococcus spp. bind the Fc region of IgG antibodies through expression of protein A (SpA). These species have consequently been a source of false-positive signals in antibody-based assays designed to detect other target bacteria. Here, flow cytometry was used to study the influence of a number of factors on the SpA-mediated binding of single cells to an anti-human IgG antibody, including strain, heat killing, overnight storage, growth phase, cell physiology, surface adhesion, and growth in model food systems. Through the costaining of antibody-stained cells with the permeability dye propidium iodide and calcein violet AM, the cell physiological status was related to SpA-mediated antibody binding. Generally, permeabilized cells lacking esterase activity did not strongly bind antibody. The binding of a number of commercially available polyclonal IgG antibodies to non-Staphylococcus spp. was also characterized. Not all SpA-expressing species showed strong binding of mouse IgG, and one species not known to express SpA showed strong binding. Most SpA-expressing strains bound rabbit IgG antibodies to some extent, whereas only one strain bound goat IgG. To reduce or eliminate SpA-mediated IgG binding, the following products were evaluated as blocking reagents and applied prior to staining with primary or secondary antibody: normal rabbit serum, mouse IgG isotype control, goat IgG, and a commercial FcR blocking reagent. Only the FcR blocking reagent consistently reduced SpA-mediated binding of Staphylococcus spp. to antibodies against other species and could be recommended as a blocking reagent in immunoassays designed to detect non-Staphylococcus species.IMPORTANCE This study characterizes a widespread but little-studied problem associated with the antibody-based detection of microbes-the Staphylococcus protein A (SpA)-mediated binding of IgG antibodies-and offers a solution: the use of commercial FcR blocking reagent. A common source of false-positive signals in the detection of microbes in clinical, food, or environmental samples can be eliminated by applying this study's findings. Using flow cytometry, the authors demonstrate the extent of heterogeneity in a culture's SpA-mediated binding of antibodies and that the degree of SpA-mediated antibody binding is strain, growth phase, and food matrix dependent and influenced by simulated food processing treatments and cell adherence. In addition, our studies of SpA-mediated binding of Staphylococcus spp. to antibodies against other bacterial species produced a very nuanced picture, leading us to recommend testing against multiple strains of S. aureus and S. hyicus of all antibodies to be incorporated into any immunoassay designed to detect a non-Staphylococcus spp.

The Emerging Role of Extracellular Vesicles in the Glioma Microenvironment: Biogenesis and Clinical Relevance.

Gliomas are a diverse group of brain tumors comprised of malignant cells (‘tumor’ cells) and non-malignant ‘normal’ cells, including neural (neurons, glia), inflammatory (microglia, macrophage) and vascular cells. Tumor heterogeneity arises in part because, within the glioma mass, both ‘tumor’ and ‘normal’ cells secrete factors that form a unique microenvironment to influence tumor progression. Extracellular vesicles (EVs) are critical mediators of intercellular communication between immediate cellular neighbors and distantly located cells in healthy tissues/organs and in tumors, including gliomas. EVs mediate cell–cell signaling as carriers of nucleic acid, lipid and protein cargo, and their content is unique to cell types and physiological states. EVs secreted by non-malignant neural cells have important physiological roles in the healthy brain, which can be altered or co-opted to promote tumor progression and metastasis, acting in combination with glioma-secreted EVs. The cell-type specificity of EV content means that ‘vesiculome’ data can potentially be used to trace the cell of origin. EVs may also serve as biomarkers to be exploited for disease diagnosis and to assess therapeutic progress. In this review, we discuss how EVs mediate intercellular communication in glioma, and their potential role as biomarkers and readouts of a therapeutic response.

Metabolism of Lactobacillus sakei Chr82 in the Presence of Different Amounts of Fermentable Sugars.

Lactobacillus sakei is widely used as a starter culture in fermented sausages since it is well adapted to meat environments and able to maintain high viability thanks to secondary pathways activated when hexoses are depleted (i.e., metabolism of pentoses and amino acids). In this study, a commercial strain of L. sakei was inoculated in a defined medium with ribose or glucose as the carbon source, at optimal or reduced concentrations, to evaluate its different physiological and metabolic responses in relation to different growth conditions. The results obtained with different approaches (HPLC, 1H-NMR, flow cytometry) evidenced different growth performances, amino acid consumptions and physiological states of cells in relation to the carbon source as an active response to harsh conditions. As expected, higher concentrations of sugars induced higher growth performances and the accumulation of organic acids. The low sugars amount induced the presence of dead cells, while injured cells increased with ribose. Arginine was the main amino acid depleted, especially in the presence of higher ribose, and resulted in the production of ornithine. Moreover, the 1H-NMR analysis evidenced a higher consumption of serine at the optimal sugars concentration (pyruvate production). This information can be helpful to optimize the use of these species in the industrial production of fermented sausages.

Application of dielectric spectroscopy to unravel the physiological state of microorganisms: current state, prospects and limits.

Microbial physiology is an essential characteristic to be considered in the research and industrial use of microorganisms. Conventionally, the study of microbial physiology has been limited to carrying out qualitative and quantitative analysis of the role of individual components in global cell behaviour at a specific time and under certain growth conditions. In this framework, groups of observable cell physiological variables that remain over time define the physiological states. Recently, with advances in omics techniques, it has been possible to demonstrate that microbial physiology is a dynamic process and that, even with low variations in environmental culture conditions, physiological changes in the cell are provoked. However, the changes cannot be detected at a macroscopic level, and it is not possible to observe these changes in real time. As an alternative to solve this inconvenience, dielectric spectroscopy has been used as a complementary technique to monitor on-line cell physiology variations to avoid long waiting times during measurements. In this review, we discuss the state-of-the-art application of dielectric spectroscopy to unravel the physiological state of microorganisms, its current state, prospects and limitations during fermentation processes. Key points • Summary of the state of the art of several issues of dielectric spectroscopy. • Discussion of correlation among dielectric properties and cell physiological states. • View of the potential use of dielectric spectroscopy in monitoring bioprocesses.

Simplified size-based immune cell monitoring using a hand-held particle counting device

Abstract Biological samples are often heterogeneous cell mixtures that differ by type and functional or responsive capacity. Beyond differences in protein expression, many cell types and physiological states are also distinguishable by size (cell diameter). The ability to distinguish population subsets is critical to many aspects of research. Such variation in cellular attributes is most commonly determined by multicolor fluorescent antibody detection of cell type-specific surface markers using flow cytometry. While flow cytometers are complex, trained operator-dependent platforms of core facilities, the availability of simplified methods for identifying activation status and measuring differences in the relative cell frequencies of more than one cell type in samples or co-cultures is somewhat limited. Moreover, despite the need for speed and accuracy, hemocytometry, the most widely used technique for cell counting, is quite tedious and fraught with user-driven variability. To address these needs, we present application of a hand-held cell counter that operates on the basic Coulter Principle of measuring changes in electrical impedance produced by particles (cells or beads) as they pass through a defined aperture. Specifically, instrumentation has been collapsed to the size of a pipette; the precision-made, microfluidic sensor contains the cell-sensing zone that enables size discrimination at the submicron with high counting accuracy. To demonstrate performance, the platform was used to assess cell distribution in human PBMC isolates and determine immune cell activation in response to CD3/CD28 co-stimulation or PHA exposure. All experiments were conducted in comparison to flow cytometry and a standard Coulter device.

Transport of bacterial cell (E. coli) from different recharge water resources in porous media during simulated artificial groundwater recharge

Commonly used recharge water resources for artificial groundwater recharge (AGR) such as secondary effluent (SE), river water and rainfall, are all oligotrophic, with low ionic strengths and different cationic compositions. The dwelling process in recharge pond imposed physiologic stress on Escherichia coli (E. coli) cells, in all three types of investigated recharge water resources and the cultivation of E. coli under varying recharge water conditions, induced changes in cell properties. During adaptation to the recharge water environment, the zeta potential of cells became more negative, the hydrodynamic diameters, extracellular polymeric substances content and surface hydrophobicity decreased, while the cellular outer membrane protein profiles became more diverse. The mobility of cells altered in accordance with changes in these cell properties. The E. coli cells in rainfall recharge water displayed the highest mobility (least retention), followed by cells in river water and finally SE cells, which had the lowest mobility. Simulated column experiments and quantitative modeling confirmed that the cellular properties, driven by the physiologic state of cells in different recharge water matrices and the solution chemistry, exerted synergistic effects on cell transport behavior. The findings of this study contribute to an improved understanding of E. coli transport in actual AGR scenarios and prediction of spreading risk in different recharge water sources.

Actin Cell Cortex: Structure and Molecular Organization.

The actin cytoskeleton consists of structurally and biochemically different actin filament arrays. Among them, the actin cortex is thought to have key roles in cell mechanics, but remains a poorly characterized part of the actin cytoskeleton. The cell cortex is typically defined as a thin layer of actin meshwork that uniformly underlies the plasma membrane of the entire cell. However, this definition applies only to specific cases. In general, the cortex structure and subcellular distribution vary significantly across cell types and physiological states of the cell. In this review, I focus on our current knowledge of the structure and molecular composition of the cell cortex.

Genomic responses of DNA methylation and transcript profiles in zebrafish cells upon nutrient deprivation stress

Environmental stress such as nutrient deprivation across multiple fields in nature causes physiological and biochemical changes in organism. Understanding the potential epigenetic modulations to phenotypic variation upon nutrient deprivation stress is crucial for environmental assessments. Here, the methyl-cytosine at single-base resolution was mapped across the whole genome and the methylation patterns and methylation levels coordinated with transcript analysis were systemically elaborated in zebrafish embryonic fibroblast cells under serum starvation stress. The down-regulated genes mainly annotated to the pathways of DNA replication and cell cycle that were consistent with cell physiological changes. Vast differentially methylated regions were identified in genomic chromosome and showed enrichment in the intron and intergenic regions. In an integrated transcriptome and DNA methylation analyses, 135 negatively correlated genes were determined, wherein the hub genes of gins2, cdca5, fbxo5, slc29a2, suv39h1b, and zgc:174160 were predominant responsive to the nutrient condition changes. Besides, nutrient recovery and DNA methyltransferases inhibitor supplements partly rescued cell proliferation with decrease of DNA methylation and reactivation of several depressed genes, implying the possible intrinsic relationships among cell physiological state, mRNA expression, and DNA methylation. Collectively, current study proved the broad role of DNA methylation in governing cellular responses to nutrient deprivation and revealed the epigenetic risk of starvation stress in zebrafish.

Respiratory Physiology of Lactococcus lactis in Chemostat Cultures and Its Effect on Cellular Robustness in Frozen and Freeze-Dried Starter Cultures.

In this study, we used chemostat cultures to analyze the quantitative effects of the specific growth rate and respiration on the metabolism in Lactococcus lactis CHCC2862 and on the downstream robustness of cells after freezing or freeze-drying. Under anaerobic conditions, metabolism remained homofermentative, although biomass yields varied with the dilution rate (D). In contrast, metabolism shifted with the dilution rate under respiration-permissive conditions. At D = 0.1 h-1, no lactate was produced, while lactate formation increased with higher dilution rates. Thus, a clear metabolic shift was observed, from flavor-forming respiratory metabolism at low specific growth rates to mixed-acid respiro-fermentative metabolism at higher specific growth rates. Quantitative analysis of the respiratory activity, lactose uptake rate, and metabolite production rates showed that aerobic acetoin formation provided most of the NADH consumed in respiration. Moreover, the maintenance-associated lactose consumption under respiration-permissive conditions was only 10% of the anaerobic value, either due to higher respiratory yield of ATP on consumed lactose or due to lower maintenance-related ATP demand. The cultivation conditions also affected the quality of the starter cultures produced. Cells harvested under respiration-permissive conditions at D = 0.1 h-1 were less robust after freeze-drying and had lower acidification activity for subsequent milk acidification, whereas respiration-permissive conditions at the higher dilution rates led to robust cells that performed equally well or better than anaerobic cells.IMPORTANCELactococcus lactis is used in large quantities by the food and biotechnology industries. L. lactis can use oxygen for respiration if heme is supplied in the growth medium. This has been extensively studied in batch cultures using various mutants, but quantitative studies of how the cell growth affects respiratory metabolism, energetics, and cell quality are surprisingly scarce. Our results demonstrate that the respiratory metabolism of L. lactis is remarkably flexible and can be modulated by controlling the specific growth rate. We also link the physiological state of cells during cultivation to the quality of frozen or freeze-dried cells, which is relevant to the industry that may lack understanding of such relationships. This study extends our knowledge of respiratory metabolism in L. lactis and its impact on frozen and freeze-dried starter culture products, and it illustrates the influence of cultivation conditions and microbial physiology on the quality of starter cultures.

Allele-specific expression changes dynamically during T cell activation in HLA and other autoimmune loci.

Genetic studies have revealed that autoimmune susceptibility variants are over-represented in memory CD4+ T cell regulatory elements1–3. Understanding how genetic variation affects gene expression in different T cell physiological states is essential for deciphering genetic mechanisms of autoimmunity4,5. Here we characterized the dynamics of genetic regulatory effects at eight time points during memory CD4+ T cell activation with high depth RNA-seq in healthy individuals. We discovered widespread dynamic allele-specific expression across the genome, where the balance of alleles changes over time. These genes were four-fold enriched within autoimmune loci. We found pervasive dynamic regulatory effects within six HLA genes. HLA-DQB1 alleles had one of three distinct transcriptional regulatory programs. Using CRISPR/Cas9 genomic editing we demonstrated that a promoter variant is causal for T cell-specific control of HLA-DQB1 expression. Our study shows that genetic variation in cis regulatory elements affects gene expression in a lymphocyte activation status-dependent manner contributing to the inter-individual complexity of immune responses.

Dynamic Imaging of Moving Cells Based on DNA Nanotechnology

Nanostructures based on DNA self-assembly have made great progress in recent years, and have been widely used. Therefore, the research method of dynamic imaging of moving cells based on DNA nanotechnology is proposed. The dynamic imaging process of moving cells is studied from two kinds of DNA Nanotechnologies: DNA gene locus marker and DNA nano-fluorescence probe. Among them, crispr-cas9 system is used to mark DNA gene sites through in vitro fluorescent labeling of different sgRNAs, which can mark different gene sites in cells in multi-color and track gene sites in living cells dynamically; based on self-assembled CdTe quantum dot @ AnnexinV-DNA nanowire fluorescent probe, based on the DNA fitness of moving cells, the system is designed to be specific to target moving cells. The specific detection of motor cells can be realized by combining the sequences. The key point is to use the structural characteristics of the probe to realize the indication of the physiological changes of the drug receiving cells. The results show that: the polychromatic labeling of different gene sites in the same cell can be realized by using different fluorescent labeled sgRNA. By using fluorescent labeled telomere specific sgRNA to track the movement of telomeres in living cells, it can be seen from the movement track that in living cells, Ma SAT is more flexible than that in living cells. About 84.5% of Ma SAT is not mobile, but only 12.9% for telomere. Ma sat and the direction of telomere movement in the cell nucleus are random and in all directions. CdTe QD @ AnnexinV-DNA nanowire fluorescent probe can not only detect the moving cells, but also indicate the physiological state of normal and apoptotic cells at the same time. A large number of S7 ends of DNA allow the probe to firmly bind to the surface of Ramos cells in the way of "twine ball." The probe can indicate the physiological state of cells, and the corresponding characteristic emission wavelength changes with the change of target cell movement state. It shows that DNA nanotechnology can be used to analyze the dynamic imaging of moving cells in all directions and from multiple angles.

A Study of a Mouse Thymus Sialidase and AIRE-Positive Neu-Medullocytes

Subtraction of sialic acids from glycans on the cell surface is important for communication between immune cells. Therefore, I hypothesized that there must be a sialidase that acts on immune cells in physiological conditions, that is, at neutral pH. Such a sialidase was examined using mouse immune tissues: the thymus, spleen and lymph node. We observed higher sialidase activity at neutral pH than acidic pH in the crude membrane fraction from the thymus but not in spleen or lymph node tissues. There is no such property among the four kinds of sialidases that have been cloned from vertebrates. We tried to clarify the true nature of the enzyme, and found NEU2-like sialidase-positive cells in the thymus histochemically using 5-bromo-4-chloro-3-indolyl-α-D-N-acetylneuraminic acid and named them Neu-medullocytes. Recently, we showed that Neu-medullocytes are CD5 positive B cells (B-1 cells), and some of them express the transcription factor autoimmune regulator (AIRE). Thus, the physiological function of these cells is probably to act as antigen-presenting cells that present carbohydrate antigens, as is characteristic of B-1 cells, during negative selection step in the thymus. The absence of autoantibodies against self-carbohydrate antigens such as blood type can be explained by the existence of these cells.

3D brain tissue physiological model with co-cultured primary neurons and glial cells in hydrogels

Recently, researchers have focused on the role of gut microbiota on human health and reported the existence of a bidirectional relationship between intestinal microbiota and the brain, referred to as microbiota-gut-brain axis (MGBA). In this context, the development of an organ-on-a-chip platform recapitulating the main players of the MGBA would help in the investigations of the biochemical mechanisms involved. In this work, we focused on the development of a new, hydrogel-based, 3D brain-like tissue model to be hosted in the brain compartment of the aforementioned platform. We previously cultured primary mouse microglial cells, cortical neurons and astrocytes independently, once embedded or covered by a millimeter layer of two selected collagen-based hydrogels. We evaluated cell metabolic activity up to 21 days, cell morphology, spatial distribution and synapse formation. Then, we exploited the best performing culturing condition and developed a more complex brain-like tissue model based on the co-culture of cortical neurons and glial cells in physiological conditions. The obtained results indicate that our 3D hydrogel-based brain tissue model is suitable to recapitulate in vitro the key biochemical parameters of brain tissue.