Types Of Cell Models Research Articles

Human LUHMES and NES cells as models for studying primary cilia in neurons.

Primary cilia are antenna-like organelles emanating from the cell surface. They are involved in cell-to-cell communication and bidirectional signal transduction to/from the extracellular environment. During brain formation, cilia critically aid in neurogenesis and maturation of neuronal structures such as axons, dendrites and synapses. Aberrations in cilia function can induce neuron differentiation defects and pathological consequences of varying severity, resulting in ciliopathies and likely a number of neurodevelopmental disorders. Despite the documented relevance of cilia for proper brain development, human neuronal models to recognize and study cilia biology are still scarce. We have established two types of cell models, Lund Human Mesencephalic (LUHMES) cells and neuroepithelial stem (NES) cells derived from induced pluripotent stem cells (iPSC), to investigate cilia biology in both proliferating neuronal progenitors/precursors and during the entire neuron differentiation and maturation process. We employ improved immunocytochemistry assays able to specifically detect cilia by confocal and super-resolution microscopy. We provide straightforward and robust methods to easily maintain cells in culture, for immunostaining and characterization of cilia orientation, anatomy and shape in human neurons across all stages of differentiation.

Cell models for micropolar fluid past a porous micropolar fluid sphere with stress jump condition

The axisymmetric creeping flow of micropolar fluid past a porous surface saturated with micropolar fluid is investigated analytically. A sphere's surface is assumed to have adequate boundary conditions, but the appropriate boundary conditions applied to its fictitious envelope differ based on the type of cell model used. For various parameter values, velocities and microrotation distributions are displayed in multiple graphs, and each is handled separately using an analytical method. The normalized hydrodynamic drag force acting on a spherical droplet-in-cell is computed for various values of volume fraction, permeability, micropolarity, and stress jump parameter. A model for the motion of micropolar porous fluid spheres in micropolar fluids in cells has good agreement with literature variable values.

Software Tool for Automatic Quantification of Sarcomere Length and Organization in Fixed and Live 2D and 3D Muscle Cell Cultures In Vitro.

Sarcomeres are the structural units of the contractile apparatus in cardiac and skeletal muscle cells. Changes in sarcomere characteristics are indicative of changes in the sarcomeric proteins and function during development and disease. Assessment of sarcomere length, alignment, and organization provides insight into disease and drug responses in striated muscle cells and models, ranging from cardiomyocytes and skeletal muscle cells derived from human pluripotent stem cells to adult muscle cells isolated from animals or humans. However, quantification of sarcomere length is typically time consuming and prone to user-specific selection bias. Automated analysis pipelines exist but these often require either specialized software or programming experience. In addition, these pipelines are often designed for only one type of cell model in vitro. Here, we present an easy-to-implement protocol and software tool for automated sarcomere length and organization quantification in a variety of striated muscle in vitro models: Two dimensional (2D) cardiomyocytes, three dimensional (3D) cardiac microtissues, isolated adult cardiomyocytes, and 3D tissue engineered skeletal muscles. Based on an existing mathematical algorithm, this image analysis software (SotaTool) automatically detects the direction in which the sarcomere organization is highest over the entire image and outputs the length and organization of sarcomeres. We also analyzed videos of live cells during contraction, thereby allowing measurement of contraction parameters like fractional shortening, contraction time, relaxation time, and beating frequency. In this protocol, we give a step-by-step guide on how to prepare, image, and automatically quantify sarcomere and contraction characteristics in different types of in vitro models and we provide basic validation and discussion of the limitations of the software tool. © 2022 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol: Staining and analyzing static hiPSC-CMs with SotaTool Alternate Protocol: Sample preparation, acquisition, and quantification of fractional shortening in live reporter hiPSC lines Support Protocol 1: Finding the image resolution Support Protocol 2: Advanced analysis settings Support Protocol 3: Finding sarcomere length in non-aligned cells.

Real-time measurement of three-dimensional morphology of blood cells in batches by non-orthogonal phase imaging

In order to overcome the shortcoming of traditional tomography requires the vast amount of data and the limitation of intersection angle between two beams existed in a microscope objective to realize the real-time detection of three-dimensional (3D) morphological distribution of blood cells in batches, a method of reconstructing cell substructure with only two non-orthogonal phases is proposed in this paper. In this work, an optimized maximum entropy tomography (MET) algorithm is used for rapid 3D reconstruction which requires less phase information from non-orthogonal directions. Moreover, two phase images can be obtained simultaneously by the phase imaging system combined with flow cytometry and optical tweezers (OT). We perform simulations of two types of cell models and experiments of red blood cell (RBC), thrombocyte and lymphocyte. Results demonstrate this method is of great significance for 3D morphological analysis of blood cells in the field of clinical diagnosis or even life sciences.

The Biological Effects of Complete Gasoline Engine Emissions Exposure in a 3D Human Airway Model (MucilAirTM) and in Human Bronchial Epithelial Cells (BEAS-2B).

The biological effects induced by complete engine emissions in a 3D model of the human airway (MucilAirTM) and in human bronchial epithelial cells (BEAS-2B) grown at the air–liquid interface were compared. The cells were exposed for one or five days to emissions generated by a Euro 5 direct injection spark ignition engine. The general condition of the cells was assessed by the measurement of transepithelial electrical resistance and mucin production. The cytotoxic effects were evaluated by adenylate kinase (AK) and lactate dehydrogenase (LDH) activity. Phosphorylation of histone H2AX was used to detect double-stranded DNA breaks. The expression of the selected 370 relevant genes was analyzed using next-generation sequencing. The exposure had minimal effects on integrity and AK leakage in both cell models. LDH activity and mucin production in BEAS-2B cells significantly increased after longer exposures; DNA breaks were also detected. The exposure affected CYP1A1 and HSPA5 expression in MucilAirTM. There were no effects of this kind observed in BEAS-2B cells; in this system gene expression was rather affected by the time of treatment. The type of cell model was the most important factor modulating gene expression. In summary, the biological effects of complete emissions exposure were weak. In the specific conditions used in this study, the effects observed in BEAS-2B cells were induced by the exposure protocol rather than by emissions and thus this cell line seems to be less suitable for analyses of longer treatment than the 3D model.

Pooled Lentiviral-Delivery Genetic Screens.

Pooled cell-based screens of mammalian genetic perturbations enable systematic large-scale, even genome-scale, evaluation of gene function. Pooled screens introduce genetic perturbations into a cell population through viral transduction such that each cell integrates into its DNA a single or small number of library perturbations with barcodes identifying the perturbations. One then selects and physically isolates the subset of cells that exhibit the phenotype of interest. Sequencing the barcodes in the hit cells reveals which genes favored or inhibited the hit phenotype. Various genetic perturbations are possible, including CRISPR gene knockout, ectopic gene expression, and RNA interference. Regardless of the type of library being screened or the type of cell model being tested, such screens involve many common steps and procedures. This unit describes detailed experimental protocols for the key steps, and also highlights some of the key factors to achieving a well-powered, reproducible screen result. © 2018 by John Wiley & Sons, Inc.

An improved TLBO with elite strategy for parameters identification of PEM fuel cell and solar cell models

Clean and renewable energy generation and supply has drawn much attention worldwide in recent years, the proton exchange membrane (PEM) fuel cells and solar cells are among the most popular technologies. Accurately modeling the PEM fuel cells as well as solar cells is critical in their applications, and this involves the identification and optimization of model parameters. This is however challenging due to the highly nonlinear and complex nature of the models. In particular for PEM fuel cells, the model has to be optimized under different operation conditions, thus making the solution space extremely complex. In this paper, an improved and simplified teaching-learning based optimization algorithm (STLBO) is proposed to identify and optimize parameters for these two types of cell models. This is achieved by introducing an elite strategy to improve the quality of population and a local search is employed to further enhance the performance of the global best solution. To improve the diversity of the local search a chaotic map is also introduced. Compared with the basic TLBO, the structure of the proposed algorithm is much simplified and the searching ability is significantly enhanced. The performance of the proposed STLBO is firstly tested and verified on two low dimension decomposable problems and twelve large scale benchmark functions, then on the parameter identification of PEM fuel cell as well as solar cell models. Intensive experimental simulations show that the proposed STLBO exhibits excellent performance in terms of the accuracy and speed, in comparison with those reported in the literature.

FEM Simulation of Elastic Properties of Closed-Cell Starch Extrudate with Spherical Pores

Three types of single closed cell model, single-centered cubic, face-centered cubic and body-centered cubic were set up based on the geometric character of corn starch extrudate. The elastic moduli were simulated with finite elements method (FEM). Fitting equation for elasticity modulus and relative density calculated from each type of cell model was developed and validated with that calculated from Ashby-Gibson equation. The accuracy of results from finite elements analysis was comparable to that of Ashby-Gibson equation.

Towards a mechanistic model for slurry transport in tumbling mills

A new modelling approach to slurry transport in dynamic beds based upon combining space and time-averaged Navier–Stokes equations with a new type of cell model is described. The resulting Ergun-like equation is used to correlate pressure drop with time-averaged distributions of the porosity, superficial fluid velocity and solids velocity for data derived from positron-emission-particle-tracking (PEPT) experiments in a scaled industrial tumbling mill fitted with lifter bars, pulp lifters and a discharge grate and run with particles and re-circulating slurry.

Transforming growth factor-β type I receptor/ALK5 contributes to doxazosin-induced apoptosis in H9C2 cells

The mechanism of doxazosin-induced apoptosis through alpha(1)-adrenoceptor-independent pathway has been reported in various types of cell models. However, the molecular events involved in this effect are still not fully discovered. In present study, we proposed that the transforming growth factor-beta type I receptor (TbetaRI/ALK5) may contribute to the doxazosin-induced apoptosis in H9C2 cardiomyoblasts. Via the detection of cell viability, apoptotic nuclei, and caspase-3 activity, we found that doxazosin induced concentration- and time-dependent apoptosis in H9C2 cells. The cell apoptosis induced by 30 muM doxazosin was exacerbated by the addition of 10 ng/ml transforming growth factor-beta1 (TGF-beta1). Doxazosin or TGF-beta1 alone respectively elevated p38 mitogen-activated protein kinases (MAPK) and Smad3 protein phosphorylation in H9C2 cells. However, the cotreatment of doxazosin and TGF-beta1 attenuated the TGF-beta1-induced Smad3 protein phosphorylation and increased doxazosin-induced p38 MAPK protein phosphorylation. Furthermore, inhibitors of TbetaRI/ALK5 (SB431542) and p38 MAPK (SB202190) or TbetaRI/ALK5 knockdown all dramatically reduced the doxazosin-induced apoptosis in H9C2 cells. In conclusion, our results demonstrated that TbetaRI/ALK5-p38 MAPK phosphorylation signaling pathway could contribute to doxazosin-induced cell apoptosis, which could be further enhanced by TGF-beta1 in association with attenuating Smad3 phosphorylation in H9C2 cells.

Apparent Viscosity of a Monodispersed Liquid Aerosol

The work presents an analytical study of the effective viscosity of a mono-dispersion of liquid aerosol droplets in a gas medium based on a steady-state low-Reynolds number hydrodynamics. The Kundsen and Reynolds numbers are assumed to be small, and thus fluid flows inside and outside the fluid particle can be described using a continuum model with a hydrodynamic slip at the drop-gas interface, while the flow fields are governed by the Stokes equations. Three types of cell models are employed to solve the problem, namely the Simha, Happel and Kuwabara cell models. Regarding the limitations of this study, the analytical expression of apparent viscosity as functions of the particle volume fraction in a closed form agree with the literature. The bulk viscosity is significantly influenced by the surface properties of the droplet-gas interface and by the internal-to-external viscosity ratio of the droplet. Generally, the influence of the concentration effect of the particles on the apparent viscosity increases with the volume fraction of the dispersed liquid drops.

Apparent Viscosity of a Monodispersed Liquid Aerosol

The work presents an analytical study of the effective viscosity of a mono-dispersion of liquid aerosol droplets in a gas medium based on a steady-state low-Reynolds number hydrodynamics. The Kundsen and Reynolds numbers are assumed to be small, and thus fluid flows inside and outside the fluid particle can be described using a continuum model with a hydrodynamic slip at the drop-gas interface, while the flow fields are governed by the Stokes equations. Three types of cell models are employed to solve the problem, namely the Simha, Happel and Kuwabara cell models. Regarding the limitations of this study, the analytical expression of apparent viscosity as functions of the particle volume fraction in a closed form agree with the literature. The bulk viscosity is significantly influenced by the surface properties of the droplet-gas interface and by the internal-to-external viscosity ratio of the droplet. Generally, the influence of the concentration effect of the particles on the apparent viscosity increases with the volume fraction of the dispersed liquid drops.