Cell Suspension Research Articles

Unveiling the potential: Extracellular vesicles from plant cell suspension cultures as a promising source.

Extracellular vesicles are secreted by all eukaryotic cells and they have an important role in intercellular signaling. Plant extracellular vesicles (PEVs) are a novel area of research that has gained attention due to their potential implications in biomolecule transport and therapeutic applications. PEVs are lipid bilayer-enclosed structures that contain a diverse cargo of biomolecules such as proteins and lipids. Moreover, it is known that PEVs have a noticeable therapeutic potential for various conditions such as inflammation and oxidative stress. However, there are critical problems such as removing the endosomes and plant-derived biomolecules that decrease the standardization and therapeutic efficacy of PEVs. In our study, the aim was to characterize plant cell suspension-derived extracellular vesicles (PCSEVs) obtained from two different plant cell suspension cultures: Stevia rebaudiana and Vaccaria hispanica. These vesicles were isolated using ultrafiltration and characterized with nanoparticle tracking analysis (NTA) and atomic force microscopy (AFM). The molecular composition of PCSEVs was profiled and the cellular uptake assay was performed. Our results demonstrated that PCSEVs have a spherical shape, less than 200 nm. In the fatty acid analysis, the primary components in PCSEVs were palmitic acid, linoleic acid, and cis-vaccenic acid. The protein content of Stevia rebaudiana-derived EVs (SDEVs) was largely associated with proteins involved in extracellular structures and functions. Conversely, Vaccaria hispanica-derived EVs (HDEVs) displayed a higher presence of cytosolic proteins. These findings contribute to the understanding of PCSEVs and open up potential avenues in extracellular vesicle research, pointing to promising prospects for future innovations in various fields.

Establishment of Physalis alkekengi cell suspension culture: time-dependent behavior of genes related to the steroidal compounds, key enzymes, and physalins under static magnetic field.

Cell suspension culture has the potential to be a valuable source for the bioactive compound productions. In this study, an optimized procedure was established for callus and cell suspension culture of Physalis alkekengi for the first time, and the impact of static magnetic field (SMF, 6 mT) was studied on the high-value metabolic compounds through investigation of signaling molecules and gene expressions at the late log-to-stationary phase. Results showed that the growth regulators of 6-benzyl amino purine (BAP, 1.5mg-1 L) and 1-naphthaleneacetic acid (NAA, 0.4mg-1 L) induced the highest fresh weight, callus rate, callus index, and total withanolides. Cell suspension culture was established in the liquid MS medium supplied with BAP (1.5mg-1 L) and NAA (0.1mg-1 L). SMF application decreased slightly the cell growth and viability and enhanced the number of round-shaped cells. The hydrogen peroxide (H2O2) and nitric oxide (NO) levels increased at an all-time series after SMF exposure, and their maximum contents were observed after 12h. A significant alteration of malondialdehydecontent was also identified after 12h of SMF exposure. The expression of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR), 1-deoxyD-xylulose 5-phosphate synthase (DXS), squalene synthase (SQS), sterol Δ7-reductase (DWF5), and C-7,8 sterol isomerase (HYD1) genes was upregulated significantly after 24 and 48h. An increase in the total withanolides was related to more activity of HMGR and DXS enzymes in SMF-exposed cells and the maximum physalin A (12.8mgg-1 DW) and physalin B (1.92mgg-1 DW) obtained after 24h compared to controls. Findings suggest that SMF can play a supportive factor in inducing steroidal compounds in P. alkekengi through modulating H2O2 and NO levels and the related-gene expressions.

BTB and CNC homology 1 deficiency disrupts intestinal IgA secretion through regulation of polymeric immunoglobulin receptor expression.

Immunoglobulin A (IgA)-mediated mucosal immunity is important for the host because it contributes to reducing infection risk and to establishing host-microbe symbiosis. BTB and CNC homology 1 (Bach1) is a transcriptional repressor with physiological and pathophysiological functions that are of particular interest for their relation to gastrointestinal diseases. However, Bach1 effects on IgA-mediated mucosal immunity remain unknown. For this study using Bach1-deficient (Bach1-/-) mice, we investigated the function of Bach1 in IgA-mediated mucosal immunity. Intestinal mucosa, feces, and plasma IgA were examined using immunosorbent assay. After cell suspensions were prepared from Peyer's patches and colonic lamina propria, they were examined using flow cytometry. The expression level of polymeric immunoglobulin receptor (pIgR), which plays an important role in the transepithelial transport of IgA, was evaluated using Western blotting, quantitative real-time PCR, and immunohistochemistry. Although no changes in the proportions of IgA-producing cells were observed, the amounts of IgA in the intestinal mucosa were increased in Bach1-/- mice. Furthermore, plasma IgA was increased in Bach1-/- mice, but fecal IgA was decreased, indicating that Bach1-/- mice have abnormal secretion of IgA into the intestinal lumen. In fact, Bach1 deficiency reduced pIgR expression in colonic mucosa at both the protein and mRNA levels. In the human intestinal epithelial cell line LS174T, suppression of Bach1 reduced pIgR mRNA stability. In contrast, overexpression of Bach1 increased pIgR mRNA stability. These results demonstrate that Bach1 deficiency causes abnormal secretion of IgA into the intestinal lumen via suppression of pIgR expression.

Parallel Multifactorial Process Optimization and Intensification for High-Yield Production of Live YF17D-Vectored Zika Vaccine

The live-attenuated yellow fever 17D strain is a potent vaccine and viral vector. Its manufacture is based on embryonated chicken eggs or adherent Vero cells. Both processes are unsuitable for rapid and scalable supply. Here, we introduce a high-throughput workflow to identify suspension cells that are fit for the high-yield production of live YF17D-based vaccines in an intensified upstream process. The use of an automated parallel ambr15 microbioreactor system for screening and process optimization has led to the identification of two promising cell lines (AGE1.CR.pIX and HEKDyn) and the establishment of optimized production conditions, which have resulted in a >100-fold increase in virus titers compared to the current state of the art using adherent Vero cells. The process can readily be scaled up from the microbioreactor scale (15 mL) to 1 L stirred tank bioreactors. The viruses produced are genetically stable and maintain their favorable safety and immunogenicity profile, as demonstrated by the absence of neurovirulence in suckling BALB/c mice and consistent seroprotection in AG129 mice. In conclusion, the presented workflow allows for the rapid establishment of a robust, scalable, and high-yield process for the production of live-attenuated orthoflavivirus vaccines, which outperforms current standards. The approach described here can serve as a model for the development of scalable processes and the optimization of yields for other virus-based vaccines that face challenges in meeting growing demands.

An easy-to-perform protocol for culturing primary murine lung tumor cells as organoids

Cancer research involves significant animal consumption and suffering. Tumor cells can be differentiated in vitro into three-dimensional organoids that resemble the primary tumor. In basic cancer research, however, tumor organoids are usually only used alongside animal experiments. We have established an easy-to-perform protocol that allows to culture KRAS-driven lung tumor cells as organoids for extended periods of time. Like the corresponding tumors in mice, the organoids produce surfactant protein C but no markers of airway epithelial cells (e.g. SCGB1A1, KRT5). The organoids can be passaged as single cell suspensions. Our organoid model contributes to replace animal experiments with cell culture systems and can be used for drug testing or functional studies in cancer research.

A Rapid Human Lung Tissue Dissociation Protocol Maximizing Cell Yield and Minimizing Cellular Stress.

The human lung is a complex organ comprised of diverse populations of epithelial, mesenchymal, vascular and immune cells, which gains even greater complexity during disease states. To effectively study the lung at a single cell level, a dissociation protocol that achieves the highest yield of viable cells of interest with minimal dissociation-associated protein or transcription changes key. Here, we detail a rapid collagenase-based dissociation protocol (Col-Short), which provides a high-yield single cell suspension suitable for a variety of downstream applications. Diseased human lung explants were obtained and dissociated through the Col-Short protocol and compared to four other dissociation protocols. Resulting single cell suspensions were then assessed with flow cytometry, differential staining, and quantitative real-time PCR to identify major hematopoietic and non-hematopoietic cell populations, as well as their activation states. We observed that the Col-Short protocol provides the greatest number of cells per gram of lung tissue with no reduction in viability when compared to previously described dissociation protocols. Col-Short had no observable surface protein marker cleavage as well as lower expression of protein activation markers and stress-related transcripts compared to four other protocols. The Col-Short dissociation protocol can be used as a rapid strategy to generate single cells for respiratory cell biology research.

Highly Sensitive Spatial Glycomics at Near-Cellular Resolution by On-Slide Derivatization and Mass Spectrometry Imaging.

Glycans on proteins and lipids play important roles in maturation and cellular interactions, contributing to a variety of biological processes. Aberrant glycosylation has been associated with various human diseases including cancer; however, elucidating the distribution and heterogeneity of glycans in complex tissue samples remains a major challenge. Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) is routinely used to analyze the spatial distribution of a variety of molecules including N-glycans directly from tissue surfaces. Sialic acids are nine carbon acidic sugars that often exist as the terminal sugars of glycans and are inherently difficult to analyze using MALDI-MSI due to their instability prone to in- and postsource decay. Here, we report on a rapid and robust method for stabilizing sialic acid on N-glycans in FFPE tissue sections. The established method derivatizes and identifies the spatial distribution of α2,3- and α2,6-linked sialic acids through complete methylamidation using methylamine and PyAOP ((7-azabenzotriazol-1-yloxy)tripyrrolidinophosphonium hexafluorophosphate). Our in situ approach increases the glycans detected and enhances the coverage of sialylated species. Using this streamlined, sensitive, and robust workflow, we rapidly characterize and spatially localize N-glycans in human tumor tissue sections. Additionally, we demonstrate this method's applicability in imaging mammalian cell suspensions directly on slides, achieving cellular resolution with minimal sample processing and cell numbers. This workflow reveals the cellular locations of distinct N-glycan species, shedding light on the biological and clinical significance of these biomolecules in human diseases.

Multi‐omics reveal the molecular basis of LrAN2 overexpression in black goji callus promoting the excessive accumulation of petanin, a promising food blue colorant

AbstractLycium ruthenicum fruit (LRF) is a potential source of natural colorant in a wide pH range due to richness in monoacylated anthocyanin petanin. However, the yield of LRF largely lags behind the market demand in food industry. In this study, overexpressing LrAN2 (LrAN2OE), an anthocyanin activator in LRF, produced excessive acylated anthocyanins including petanin in L. ruthenicum callus (LRC). Physiological analysis indicates that LrAN2OE extensively orchestrate the redox homeostasis, including antioxidant enzymes system and antioxidants with low molecular weight. KEGG enrichment analysis indicates that LrAN2 hierarchically orchestrate the acylated anthocyanin biosynthesis in LRC at multi‐omics level, such as small RNAome, transcriptome, and metabolome. The anthocyanin yield of LrAN2OE callus cultured by 5% sucrose or glucose is significantly enhanced. Furthermore, the anthocyanin yield approach to 96.23 mg/g dry weight, approximately 3.5 folds of that in LRF, when LrAN2OE suspension cells are cultured in liquid MS medium supplement with 5% sucrose and 100 mM NaCl. Notably, anthocyanins extracted from LrAN2OE callus are stable in pH 1.0–2.0, pH 7.0, and pH 9.0, showing red or blue color within 30 days at 4°C. Our findings suggest that LrAN2 is perfect gene resource for metabolic engineering of acylated anthocyanins in LRC, a promising chassis producing acylated anthocyanins. Taken together, LRC metabolically engineered by LrAN2 is a potential source of natural food color, which facilitates to make up the shortfall of LRF as source of natural colorant in future food industry.

Cryopreservation of Mesenchymal Stem/Stromal Cells using a DMSO-free Solution is Comparable to DMSO-containing Cryoprotectants: Results of An International Multicenter PACT/BEST Collaborative Study

Background and AimAn essential aspect of ensuring availability and stability of mesenchymal stem/stromal cells (MSCs) products for clinical use is that these cells are cryopreserved before individual infusion into patients. Currently, cryopreservation of MSCs involves use of a cryoprotectant solution containing dimethyl sulfoxide (DMSO). However, it is recognized that DMSO may be toxic for both the patient and the MSC product. In this Production Assistance for Cellular Therapies (PACT) and Biomedical Excellence for Safer Transfusion (BEST) Collaborative study, we compared a novel DMSO-free solution with DMSO containing cryoprotectant solutions for freezing MSCs. MethodsA DMSO-free cryoprotectant solution containing sucrose, glycerol, and isoleucine (SGI) in a base of Plasmalyte A was prepared at the University of Minnesota. Cryoprotectant solutions containing 5-10% DMSO (in-house) were prepared at seven participating centers (five from USA, one each from Australia and Germany). The MSCs were isolated from bone marrow or adipose tissue and cultured ex vivo per local protocols at each center. The cells in suspension were frozen by aliquoting into vials/bags. For six out of the seven centers, the vials/bags were placed in a controlled rate freezer (one center placed them at -80°C freezer overnight) before transferring to liquid nitrogen. The cells were kept frozen for at least one week before thawing and testing. Pre- and post-thaw assessment included cell viability and recovery, immunophenotype as well as transcriptional and gene expression profiles. Linear regression, mixed effects models and two-sided t-tests were applied for statistical analysis. ResultsMSCs had an average viability of 94.3% (95% CI, 87.2-100%) before cryopreservation, decreasing by 4.5% (95% CI: 0.03-9.0%; p: 0.049) and 11.4% (95% CI: 6.9-15.8%; p<0.001), for MSCs cryopreserved in the in-house and SGI solutions, respectively. The average recovery of viable MSCs cryopreserved in the SGI was 92.9% (95% CI: 85.7-100.0%), and it was lower by 5.6% (95% CI: 1.3-9.8%, p<0.013) for the in-house solution. Additionally, MSCs cryopreserved in the two solutions had expected level of expressions for CD45, CD73, CD90 and CD105 with no significant difference in global gene expression profiles. ConclusionMSCs cryopreserved in a DMSO-free solution containing sucrose, glycerol, and isoleucine in a base of Plasmalyte A had slightly lower cell viability, better recovery, and comparable immunophenotype and global gene expression profiles compared to MSCs cryopreserved in DMSO containing solutions. The average viability of MSCs in the novel solution was above 80% and, thus, likely clinically acceptable. Future studies are suggested to test the post-thaw functions of MSCs cryopreserved in the novel DMSO-free solution.

Establishment and Identification of Bladder Cancer Cell Sheet

Cell sheet technology (CST) has primarily been applied in tissue engineering for repair purposes. Our preliminary research indicates that an in vivo prostate cancer model established using CST outperforms traditional cell suspension methods. However, the potential for CST to be used with bladder cancer cells has not yet been explored. In this study, we investigated the ability of two bladder cancer cell lines, T24 and 5637, to form cell sheets. We found that T24 cells successfully formed cell sheets. We then performed staining to evaluate the integrity, specific markers, and proliferation characteristics of the T24 cell sheets. Our findings demonstrate that bladder cancer cell sheets can be established, providing a valuable tool for both in vivo and in vitro bladder cancer studies and for personalized drug selection for patients.

Cell attachment defines sensitivity to cold stress via the Hippo pathway

Although cells are frequently maintained at cold temperatures during experiments, the effects of cold stress on cell viability and subsequent cellular conditions remain elusive. In this study, we investigated the effects of cold stress on cancer cells under various culture conditions. We showed that cold stress induces ferroptosis, a form of cell death characterized by lipid peroxidation, in sensitive cancer cell lines. High cell density and serum starvation activate the Hippo pathway and suppress cold-induced cell death. Genetic deletion of Hippo pathway components enhances cold stress susceptibility. Furthermore, the cell attachment status influences the response to cold stress, with suspended cells showing greater resistance and faster recovery than attached cells. This study highlights the importance of cellular conditions and the Hippo pathway in the handling and storage of cancer cells at cold temperatures, thereby offering insights into experimental and clinical contexts.

Promotion of perineural invasion of cholangiocarcinoma by Schwann cells via nerve growth factor.

Cholangiocarcinoma (CCA), a highly lethal tumor of the hepatobiliary system originating from bile duct epithelium, can be divided into the intrahepatic, hilar, and extrahepatic types. Due to its insidious onset and atypical early clinical symptoms, the overall prognosis is poor. One of the important factors contributing to the poor prognosis of CCA is the occurrence of perineural invasion (PNI), but the specific mechanisms regarding how it contributes to the occurrence of PNI are still unclear. The main purpose of this study is to explore the molecular mechanism leading to the occurrence of PNI and provide new ideas for clinical treatment. CCA cell lines and Schwann cells (SCs) were stimulated to observe the changes in cell behavior. SCs cocultured with tumor supernatant and SCs cultured in normal medium were subjected to transcriptome sequencing to screen the significantly upregulated genes. Following this, the two types of tumor cells were cultured with SC supernatant, and the changes in behavior of the tumor cells were observed. Nonobese diabetic-severe combined immunodeficiency disease (NOD-SCID) mice were injected with cell suspension supplemented with nerve growth factor (NGF) via the sciatic nerve. Four weeks later, the mice were euthanized and the tumor sections were removed and stained. Nerve invasion by tumor cells was common in CCA tissues. SCs were observed in tumor tissues, and the number of SCs in tumor tissues and the degree of PNI were much higher than were those in normal tissues or tissues without PNI. The overall survival time was shorter in patients with CCA with PNI than in patients without PNI. SCs were enriched in CCA tissues, indicating the presence of PNI and associated with poor prognosis in CCA patients. CCA was found to promote NGF secretion from SCs in vitro. After the addition of exogenous NGF in CCA cell culture medium, the proliferation activity and migration ability of CCA cells were significantly increased, suggesting that SCs can promote the proliferation and migration of CCA through the secretion of NGF. NGF, in turn, was observed to promote epithelial-mesenchymal transition in CCA through tropomyosin receptor kinase A (TrkA), thus promoting its progression. Tumor growth in mice shows that NGF can promote PNI in CCA. In CCA, tumor cells can promote the secretion of NGF by SCs, which promotes the progression of CCA and PNI by binding to its high-affinity receptor TrkA, leading to poor prognosis.

Development of a Long-Amplicon Propidium Monoazide-Quantitative PCR Assay for Detection of Viable Xanthomonas arboricola pv. pruni Cells in Peach Trees.

Bacterial spot is one of the most serious diseases of peach caused by the pathogen Xanthomonas arboricola pv. pruni (XAP), leading to early defoliation and unmarketable fruit. The pathogen can overwinter in peach twigs and form spring cankers, which are considered the primary inoculum source for early season leaf and fruitlet infection. The amount of overwintering bacterial inoculum plays a critical role for the bacterial spot development, but no reliable quantification method is available. Thus, we developed a long-amplicon propidium monoazide (PMA)-quantitative PCR (qPCR) assay for specific detection of viable XAP cells. The optimized PMA-qPCR assay used 20 μM of PMAxx for pure bacterial suspensions and 100 μM for peach twig tissues. The Qiagen Plant Pro Kit with an additional lysozyme digestion step was the DNA extraction protocol that yielded the best detection sensitivity with the bacteria-spiked peach twig extracts. The PMA-qPCR assay was tested with different mixtures of viable and heat-killed XAP cells in pure bacterial suspensions and bacteria-spiked peach twig tissues. The results showed that this assay enabled sensitive, specific, and accurate quantification of viable XAP cells as low as 103 CFU/ml with the presence of up to 107 CFU/ml of dead XAP cells, while suppressing the amplification of DNA from dead cells. For mixtures of viable and dead cells, the PMA-qPCR results were linearly correlated with the predicted concentrations of viable XAP (R2 > 0.98). Thus, the PMA-qPCR assay will be a suitable tool for quantifying overwintering XAP population on peach trees.

The Relationship Between Perioperative Blood Product Use and the Incidence of Postoperative Renal Injury in Infants Undergoing Cardiac Surgery

Cardiac Surgery Associated Acute Kidney Injury (CS-AKI) is a serious complication that occurs in patients following cardiac surgery. It is characterized by the rapid decline in kidney function, leading to potential long-term kidney damage or even kidney failure. CS-AKI is a significant health concern, as it not only prolongs hospital stays and recovery time but also increases the risk of mortality. This study, conducted as a prospective observational study, aimed to investigate the relationship between perioperative blood product use and the incidence of postoperative acute kidney injury (AKI) in infants and young children undergoing cardiac surgery. It examined the perioperative use of these blood products and its association with the occurrence of AKI. The findings of this study revealed a significant association between the use of red blood cell suspension and platelets and the development of postoperative AKI. This suggests that the administration of these blood products during cardiac surgery may increase the risk of kidney injury in infants and young children. However, it is important to note that the study did not find a statistically significant association between plasma transfusion volume and the incidence of AKI. This suggests that while the use of certain blood products may contribute to the risk of AKI, the volume of plasma transfused does not seem to have a significant impact. The findings of this study provide valuable insights into the perioperative management of infants and young children undergoing cardiac surgery. It underscores the importance of carefully considering the use of blood products during surgery and taking necessary measures to minimize the risk of AKI.

High throughput cell mechanotyping of cell response to cytoskeletal modulations using a microfluidic cell deformation system.

Cellular mechanical properties influence cellular functions across pathological and physiological systems. The observation of these mechanical properties is limited in part by methods with a low throughput of acquisition or with low accessibility. To overcome these limitations, we have designed, developed, validated, and optimized a microfluidic cellular deformation system (MCDS) capable of mechanotyping suspended cells on a population level at a high throughput rate of ∼300 cells pers second. The MCDS provides researchers with a viable method for efficiently quantifying cellular mechanical properties towards defining prognostic implications of mechanical changes in pathology or screening drugs to modulate cytoskeletal integrity.

DIPG-08. PROBING THE BLOOD-BRAIN-TUMOR-BARRIER WITH A MICROVASCULAR MODEL OF DIFFUSE MIDLINE GLIOMA

Abstract BACKGROUND Pediatric diffuse midline glioma (DMG) is a uniformly fatal brain tumor in children, with most patients surviving less than 12 months. Current treatment for DMG is limited, and outcomes for this tumor have not improved. The blood-brain-barrier (BBB) remains a key challenge for DMG therapeutics, preventing most drugs from entering brain tissue. Functional characterization of the blood-brain-tumor-barrier (BBTB) – the interaction between tumors and BBB vasculature – remains largely unexplored for DMG. There is a need for a preclinical model of DMG that can probe the functional, physiological, and biological properties of the BBTB in vitro as a platform to evaluate therapeutic efficacy that is representative of human physiology. METHODS To generate an in vitro model of DMG with human microvasculature (DMG-BBTB model), we co-cultured DMG neurospheres, human brain microvascular endothelial cells, human brain vascular pericytes, and human astrocytes. Cells are simultaneously seeded into microfluidic devices at varied concentrations within a fibrin matrix. Self-assembled microvascular networks are formed within 7-8 days and used for downstream functional and phenotypic assays. RESULTS Vascular morphology and solute permeability in microvascular networks are influenced by cell identity, growth pattern, and relative concentration. We show that DMG neurospheres exhibit different patterns of growth when co-cultured as uniform spheroids versus single cells in suspension. Devices representing each growth pattern are further characterized for paracellular diffusion and permeability compared to devices without DMG cells through perfusion of high molecular weight dextran. Permeability values are correlated to biologic features such as the abundance and localization of junctional proteins and transporters. CONCLUSIONS We developed a platform to evaluate the microvasculature of the DMG BBTB as a tool to develop new therapies informed by vascular biology. We probed the functional, physiological, and biological properties of the human DMG BBTB in vitro, and in ongoing work are assessing approved and experimental therapeutics.

Unbiased method for spectral analysis of cells with great diversity of autofluorescence spectra.

Autofluorescence is an intrinsic feature of cells, caused by the natural emission of light by photo-excitatory molecular content, which can complicate analysis of flow cytometry data. Different cell types have different autofluorescence spectra and, even within one cell type, heterogeneity of autofluorescence spectra can be present, for example, as a consequence of activation status or metabolic changes. By using full spectrum flow cytometry, the emission spectrum of a fluorochrome is captured by a set of photo detectors across a range of wavelengths, creating an unique signature for that fluorochrome. This signature is then used to identify, or unmix, that fluorochrome's unique spectrum from a multicolor sample containing different fluorescent molecules. Importantly, this means that this technology can also be used to identify intrinsic autofluorescence signal of an unstained sample, which can be used for unmixing purposes and to separate the autofluorescence signal from the fluorophore signals. However, this only works if the sample has a singular, relatively homogeneous and bright autofluorescence spectrum. To analyze samples with heterogeneous autofluorescence spectral profiles, we setup an unbiased workflow to more quickly identify differing autofluorescence spectra present in a sample to include as "autofluorescence signatures" during the unmixing of the full stained samples. First, clusters of cells with similar autofluorescence spectra are identified by unbiased dimensional reduction and clustering of unstained cells. Then, unique autofluorescence clusters are determined and are used to improve the unmixing accuracy of the full stained sample. Independent of the intensity of the autofluorescence and immunophenotyping of cell subsets, this unbiased method allows for the identification of most of the distinct autofluorescence spectra present in a sample, leading to less confounding autofluorescence spillover and spread into extrinsic phenotyping markers. Furthermore, this method is equally useful for spectral analysis of different biological samples, including tissue cell suspensions, peripheral blood mononuclear cells, and in vitro cultures of (primary) cells.

Cell size and deformation measurement using constrictions integrated into a microfluidic device

In this study, we developed a microfluidic device to evaluate cell size and deformability. As a specific method, a physical pushing load was applied to the cells using a channel having a constriction with a height of 1 μm. In addition, by orienting the constriction in a vertical direction, it was possible to measure the cell area easily using a microscope under load. The system constructed in this study can evaluate the contact area between the cells and the glass surface before and after applying a load under a microscope. The only input parameter was the syringe flow rate, and it was possible to evaluate multiple cells in a cell suspension simultaneously. Also, since the flow rate is 50 μm min−1 or less, there is no need for a high-speed camera. This time, we evaluated cell types with different characteristics: NIH/3T3 and smooth muscle cells (SMC). To evaluate deformability, we focused on the circularity of the cells during load application. Due to the influence of the flow within the channel, cells with high deformability assumed an almost elliptical shape and flowed through the constriction. Using the device developed in this study, we confirmed that SMCs, which are muscle cells, have large variations in cell size and hardness among individual cells. Finally, we discussed these results and possible future applications.

Aortic Valve Stenosis Causes Accumulation of Extracellular Hemoglobin and Systemic Endothelial Dysfunction.

Whether aortic valve stenosis (AS) can adversely affect systemic endothelial function independently of standard modifiable cardiovascular risk factors is unknown. We therefore investigated endothelial and cardiac function in an experimental model of AS mice devoid of standard modifiable cardiovascular risk factors and human cohorts with AS scheduled for transcatheter aortic valve replacement. Endothelial function was determined by flow-mediated dilation using ultrasound. Extracellular hemoglobin (eHb) concentrations and NO consumption were determined in blood plasma of mice and humans by ELISA and chemiluminescence. This was complemented by measurements of aortic blood flow using 4-dimensional flow acquisition by magnetic resonance imaging and computational fluid dynamics simulations. The effects of plasma and red blood cell (RBC) suspensions on vascular function were determined in transfer experiments in a murine vasorelaxation bioassay system. In mice, the induction of AS caused systemic endothelial dysfunction. In the presence of normal systolic left ventricular function and mild hypertrophy, the increase in the transvalvular gradient was associated with elevated eryptosis, increased eHb and plasma NO consumption; eHb sequestration by haptoglobin restored endothelial function. Because the aortic valve orifice area in patients with AS decreased, postvalvular mechanical stress in the central ascending aorta increased. This was associated with elevated eHb, circulating RBC-derived microvesicles, eryptotic cells, lower haptoglobin levels without clinically relevant anemia, and consecutive endothelial dysfunction. Transfer experiments demonstrated that reduction of eHb by treatment with haptoglobin or elimination of fluid dynamic stress by transcatheter aortic valve replacement restored endothelial function. In patients with AS and subclinical RBC fragmentation, the remaining circulating RBCs before and after transcatheter aortic valve replacement exhibited intact membrane function, deformability, and resistance to osmotic and hypoxic stress. AS increases postvalvular swirling blood flow in the central ascending aorta, triggering RBC fragmentation with the accumulation of hemoglobin in the plasma. This increases NO consumption in blood, thereby limiting vascular NO bioavailability. Thus, AS itself promotes systemic endothelial dysfunction independent of other established risk factors. Transcatheter aortic valve replacement is capable of limiting NO scavenging and rescuing endothelial function by realigning postvalvular blood flow to near physiological patterns. URL: https://www.clinicaltrials.gov; Unique identifier: NCT05603520. URL: https://www.clinicaltrials.gov; Unique identifier: NCT01805739.

Extracellular vesicles derived from stored red blood cell suspensions enhance invasion and migration of lung cancer cells by miR1246 and miR150-3p.

Aged red blood cell (RBC) transfusions in lung cancer patients are often related to cancer recurrence and shorter lifespans. Extracellular vesicles (EVs) accumulated in stored RBC suspensions may be one of the important influential factors. This study aims to investigate how EVs derived from RBC suspensions affect the progress of lung cancer through the most enriched microRNAs (miRNAs) previously reported in our research. EVs derived from stored RBC suspensions in Weeks 1, 3 and 5 were harvested via ultracentrifugation. Lung adenocarcinoma H1975 cells were co-cultured with EVs and transfected with miR1246 and miR150-3p mimics to evaluate alterations in their proliferation, invasion and migration abilities in vitro. Proteomics and bioinformatics were performed to predict the signalling pathway related to invasion and migration of H1975, which were verified by western blotting (WB) and flow cytometry. EVs derived from stored RBC suspensions in Weeks 3 and 5 could significantly enhance the invasion and migration ability of H1975 cells and also increase the expression of miR1246 and miR150-3p. After transfection with miR1246 and miR150-3p mimics, invasion, migration and proliferation of H1975 cells were obviously enhanced. Proteomics analysis demonstrated that EVs co-cultivation and miRNA transfection groups were both enriched in cell adhesion molecules. WB and cytometry indicated that integrin beta-1 (ITGB1) and Rap1b were increased. EVs derived from stored RBC suspensions can enhance invasion and migration ability of lung cancer cells via the most accumulated miR1246 and miR150-3p, which may increase the expression of ITGB1 through Rap1 signalling pathway.