scholarly journals Novel Quantitative Biosystem for Modeling Physiological Fluid Shear Stress on Cells

2006 ◽  
Vol 73 (3) ◽  
pp. 699-705 ◽  
Author(s):  
Eric A. Nauman ◽  
C. Mark Ott ◽  
Ed Sander ◽  
Don L. Tucker ◽  
Duane Pierson ◽  
...  
Keyword(s):  
Fluid Shear Stress ◽  
Bacterial Pathogen ◽  
Cell Types ◽  
Quantitative Model ◽  
Culture Conditions ◽  
Cellular Interactions ◽  
Fluid Shear ◽  
Physiological Fluid ◽  
Phenotypic Responses

ABSTRACT The response of microbes to changes in the mechanical force of fluid shear has important implications for pathogens, which experience wide fluctuations in fluid shear in vivo during infection. However, the majority of studies have not cultured microbes under physiological fluid shear conditions within a range commonly encountered by microbes during host-pathogen interactions. Here we describe a convenient batch culture biosystem in which (i) the levels of fluid shear force can be varied within physiologically relevant ranges and quantified via mathematical models and (ii) large numbers of cells can be planktonically grown and harvested to examine the effect of fluid shear levels on microbial genomic and phenotypic responses. A quantitative model based on numerical simulations and in situ imaging analysis was developed to calculate the fluid shear imparted by spherical beads of different sizes on bacterial cell cultures grown in a rotating wall vessel (RWV) bioreactor. To demonstrate the application of this model, we subjected cultures of the bacterial pathogen Salmonella enterica serovar Typhimurium to three physiologically-relevant fluid shear ranges during growth in the RVW and demonstrated a progressive relationship between the applied fluid shear and the bacterial genetic and phenotypic responses. By applying this model to different cell types, including other bacterial pathogens, entire classes of genes and proteins involved in cellular interactions may be discovered that have not previously been identified during growth under conventional culture conditions, leading to new targets for vaccine and therapeutic development.

scholarly journals Effects of compound stimulation of fluid shear stress plus ultrasound on stem cell proliferation and osteogenesis

2021 ◽  
Author(s):  
Lingzhi Jing ◽  
Suna Fan ◽  
Xiang Yao ◽  
Yaopeng Zhang
Keyword(s):  
Cell Proliferation ◽  
Shear Stress ◽  
Stem Cell ◽  
Fluid Shear Stress ◽  
Culture Conditions ◽  
Fluid Shear ◽  
Ultrasound Stimulation ◽  
Orthopedic Diseases ◽  
Stimulation Of

Abstract Bone tissue with strong adaptability is often in a complex dynamical microenvironment in vivo, which is associated with the pathogenesis and treatment of orthopedic diseases. Therefore, it is of great significance to investigate the effects of corresponding compound stimulation on cell behaviors. Herein, a fluid shear stress (FSS) plus ultrasound stimulation platform suitable for cell studies based on a microfluidic chip was constructed and bone marrow mesenchymal stem cell (BMSC) was chosen as a model cell. The proliferation and osteogenesis of BMSCs under the compound stimulation of FSS plus ultrasound in growth medium without any soluble induction factors were firstly investigated. Single FSS stimulation and static culture conditions were also examined. Results illustrated that suitable single FSS stimulation (about 0.06 dyn/cm2) could significantly enhance cell proliferation and osteogenesis simultaneously when compare to the static control, while greater FSS mitigated or even restricted these enhancing effects. Interestingly, ultrasound stimulation combined with this suitable FSS stimulation further accelerated cell proliferation as the intensity of ultrasound increasing. As for the osteogenesis under compound stimulation, it was relatively restricted under lower ultrasound intensity (about 0.075 W/cm2), while promoted when the intensity became higher (about 1.75W/cm2). This study suggests that both the cell proliferation and osteogenesis are very responsive to the magnitudes of FSS and ultrasound stimulations and can be both significantly enhanced by proper combination strategies. Moreover, these findings will provide valuable references for the construction of effective cell bioreactors and also the treatment of orthopedic diseases.

Ultrastructural Study of a differentiating human colon carcinoma cell line

1990 ◽  
Vol 48 (3) ◽  
pp. 208-209
Author(s):  
Sylvie Polak-Charcon ◽  
Mehrdad Hekmati ◽  
Yehuda Ben Shaul
Keyword(s):  
Cell Line ◽  
Morphological Changes ◽  
Secretory Granules ◽  
Human Colon ◽  
Cell Types ◽  
Culture Conditions ◽  
Morphological Evidence ◽  
Human Colon Carcinoma Cell ◽  
Colon Cell

The epithelium of normal human colon mucosa “in vivo” exhibits a gradual pattern of differentiation as undifferentiated stem cells from the base of the crypt of “lieberkuhn” rapidly divide, differentiate and migrate toward the free surface. The major differentiated cell type of the intestine observed are: absorptive cells displaying brush border, goblet cells containing mucous granules, Paneth and endocrine cells containing dense secretory granules. These different cell types are also found in the intestine of the 13-14 week old embryo.We present here morphological evidence showing that HT29, an adenocarcinoma of the human colon cell line, can differentiate into various cell types by changing the growth and culture conditions and mimic morphological changes found during development of the intestine in the human embryo.HT29 cells grown in tissue-culture dishes in DMEM and 10% FCS form at late confluence a multilayer of morphologically undifferentiated cell culture covered with irregular microvilli, and devoid of tight junctions (Figs 1-3).

scholarly journals Proximal tubule apical endocytosis is modulated by fluid shear stress via an mTOR-dependent pathway

2017 ◽  
Vol 28 (19) ◽  
pp. 2508-2517 ◽  
Author(s):  
Kimberly R. Long ◽  
Katherine E. Shipman ◽  
Youssef Rbaibi ◽  
Elizabeth V. Menshikova ◽  
Vladimir B. Ritov ◽  
...  
Keyword(s):  
Shear Stress ◽  
Ion Transport ◽  
Proximal Tubule ◽  
Fluid Shear Stress ◽  
Kidney Development ◽  
Endocytic Pathway ◽  
Fluid Shear ◽  
Intermediate Phenotypes ◽  
Glomerulotubular Balance

Cells lining the proximal tubule (PT) have unique membrane specializations that are required to maintain the high-capacity ion transport and endocytic functions of this nephron segment. PT cells in vivo acutely regulate ion transport in response to changes in glomerular filtration rate (GFR) to maintain glomerulotubular balance. PT cells in culture up-regulate endocytic capacity in response to acute changes in fluid shear stress (FSS); however, it is not known whether GFR modulates PT endocytosis to enable maximally efficient uptake of filtered proteins in vivo. Here, we show that cells cultured under continuous FSS develop an expanded apical endocytic pathway and increased endocytic capacity and lysosomal biogenesis. Furthermore, endocytic capacity in fully differentiated cells is rapidly modulated by changes in FSS. PT cells exposed to continuous FSS also acquired an extensive brush border and basolateral membrane invaginations resembling those observed in vivo. Culture under suboptimal levels of FSS led to intermediate phenotypes, suggesting a threshold effect. Cells exposed to FSS expressed higher levels of key proteins necessary for PT function, including ion transporters, receptors, and membrane-trafficking machinery, and increased adenine nucleotide levels. Inhibition of the mechanistic target of rapamycin (mTOR) using rapamycin prevented the increase in cellular energy levels, lysosomal biogenesis, and endocytic uptake, suggesting that these represent a coordinated differentiation program. In contrast, rapamycin did not prevent the FSS-induced increase in Na+/K+-ATPase levels. Our data suggest that rapid tuning of the endocytic response by changes in FSS may contribute to glomerulotubular balance in vivo. Moreover, FSS provides an essential stimulus in the differentiation of PT cells via separate pathways that up-regulate endocytosis and ion transport capacity. Variations in FSS may also contribute to the maturation of PT cells during kidney development and during repair after kidney injury.

scholarly journals ShearFAST: a user-friendly in vitro toolset for high throughput, inexpensive fluid shear stress experiments.

2020 ◽  
Author(s):  
Thomas Brendan Smith ◽  
Alessandro Marco De Nunzio ◽  
Kamlesh Patel ◽  
Haydn Munford ◽  
Tabeer Alam ◽  
...  
Keyword(s):  
Shear Stress ◽  
High Throughput ◽  
Fluid Shear Stress ◽  
Tracking System ◽  
Frequency Measurement ◽  
Camera Motion ◽  
Fluid Shear ◽  
Mean Frequency

Fluid shear stress is a key modulator of cellular physiology in vitro and in vivo, but its effects are under-investigated due to requirements for complicated induction methods. Herein we report the validation of ShearFAST; a smartphone application that measures the rocking profile on a standard laboratory cell rocker and calculates the resulting shear stress arising in tissue culture plates. The accuracy with which this novel approach measured rocking profiles was validated against a graphical analysis, and also against measures reported by an 8-camera motion tracking system. ShearFASTs angle assessments correlated well with both analyses (r ≥0.99, p ≤0.001) with no significant differences in pitch detected across the range of rocking angles tested. Rocking frequency assessment by ShearFAST also correlated well when compared to the two independent validatory techniques (r ≥0.99, p ≤0.0001), with excellent reproducibility between ShearFAST and video analysis (mean frequency measurement difference of 0.006 ± 0.005Hz) and motion capture analysis (mean frequency measurement difference of 0.008 ± 0.012Hz). These data make the ShearFAST assisted cell rocker model make it an attractive approach for economical, high throughput fluid shear stress experiments. Proof of concept data presented reveals a protective effect of low-level shear stress on renal proximal tubule cells submitted to simulations of pretransplant storage.

Common precursors for neural and mesectodermal derivatives in the cephalic neural crest

Development ◽  
1991 ◽  
Vol 112 (1) ◽  
pp. 301-305 ◽  
Author(s):  
A. Baroffio ◽  
E. Dupin ◽  
N.M. Le Douarin
Keyword(s):  
Neural Crest ◽  
Cell Types ◽  
Culture Conditions ◽  
Pigment Cells ◽  
Stem Cell Population ◽  
Multipotent Cells ◽  
Clonal Cultures ◽  
Vertebrate Embryos ◽  
Derivatives Of

The cephalic neural crest (NC) of vertebrate embryos yields a variety of cell types belonging to the neuronal, glial, melanocytic and mesectodermal lineages. Using clonal cultures of quail migrating cephalic NC cells, we demonstrated that neurons and glial cells of the peripheral nervous system can originate from the same progenitors as cartilage, one of the mesectodermal derivatives of the NC. Moreover, we obtained evidence that the migrating cephalic NC contains a few highly multipotent precursors that are common to neurons, glia, cartilage and pigment cells and which we interprete as representative of a stem cell population. In contrast, other NC cells, although provided with identical culture conditions, give rise to clones composed of only one or some of these cell types. These cells thus appear restricted in their developmental potentialities compared to multipotent cells. It is therefore proposed that, in vivo, the active proliferation of pluripotent NC cells during the migration process generates distinct subpopulations of cells that become progressively committed to different developmental fates.

scholarly journals Modulating the Substrate Stiffness to Manipulate Differentiation of Resident Liver Stem Cells and to Improve the Differentiation State of Hepatocytes

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Angela Maria Cozzolino ◽  
Valeria Noce ◽  
Cecilia Battistelli ◽  
Alessandra Marchetti ◽  
Germana Grassi ◽  
...  
Keyword(s):  
Stem Cells ◽  
Culture Method ◽  
Cell Types ◽  
Culture Conditions ◽  
Precursor Cells ◽  
Substrate Stiffness ◽  
Growth And Survival ◽  
Liver Stem Cells

In many cell types, several cellular processes, such as differentiation of stem/precursor cells, maintenance of differentiated phenotype, motility, adhesion, growth, and survival, strictly depend on the stiffness of extracellular matrix that,in vivo, characterizes their correspondent organ and tissue. In the liver, the stromal rigidity is essential to obtain the correct organ physiology whereas any alteration causes liver cell dysfunctions. The rigidity of the substrate is an element no longer negligible for the cultivation of several cell types, so that many data so far obtained, where cells have been cultured on plastic, could be revised. Regarding liver cells, standard culture conditions lead to the dedifferentiation of primary hepatocytes, transdifferentiation of stellate cells into myofibroblasts, and loss of fenestration of sinusoidal endothelium. Furthermore, standard cultivation of liver stem/precursor cells impedes an efficient execution of the epithelial/hepatocyte differentiation program, leading to the expansion of a cell population expressing only partially liver functions and products. Overcoming these limitations is mandatory for any approach of liver tissue engineering. Here we propose cell lines asin vitromodels of liver stem cells and hepatocytes and an innovative culture method that takes into account the substrate stiffness to obtain, respectively, a rapid and efficient differentiation process and the maintenance of the fully differentiated phenotype.

Nanoparticle localization in blood vessels: dependence on fluid shear stress, flow disturbances, and flow-induced changes in endothelial physiology

Nanoscale ◽  
2018 ◽  
Vol 10 (32) ◽  
pp. 15249-15261 ◽  
Author(s):  
M. Juliana Gomez-Garcia ◽  
Amber L. Doiron ◽  
Robyn R. M. Steele ◽  
Hagar I. Labouta ◽  
Bahareh Vafadar ◽  
...  
Keyword(s):  
Shear Stress ◽  
Fluid Shear Stress ◽  
Fluid Shear ◽  
Nanoparticle Distribution ◽  
Flow Models ◽  
Flow Disturbances ◽  
Induced Changes ◽  
Stress Flow

Hemodynamic factors drive nanoparticle distribution in vivo and in vitro in cell-based flow models.

Engineering cooperative patterns in multi-species bacterial colonies

2019 ◽  
Author(s):  
A. I. Curatolo ◽  
N. Zhou ◽  
Y. Zhao ◽  
C. Liu ◽  
A. Daerr ◽  
...  
Keyword(s):  
Population Level ◽  
Spatial Arrangement ◽  
Cell Types ◽  
Living Systems ◽  
Cellular Interactions ◽  
Cellular Motility ◽  
Periodic Patterns ◽  
Form Complex ◽  
Theoretical Approaches

Self-organization is a hallmark of all living systems [1]. In particular, coordinated cellular behavior, commonly orchestrated at the population level through reciprocal interactions among different cell species [2–4], regulates the spatial arrangement of specialized cell types to generate tissue patterning and form complex body layouts [5, 6]. The overwhelming complexity of living systems, however, makes deciphering the underlying mechanisms difficult and limits our knowledge of basic pattern-forming mechanism in vivo [7, 8]. A successful strategy is then to work with synthetic, engineered systems, in which cellular interactions can be more easily tailored and studied [9–13]. Here, we demonstrate a simple mechanism through which different populations of cells can self-organize in periodic patterns. Programmed population interactions are shown to lead to coordinated out-ofphase spatial oscillations of two engineered populations of Escherichia coli. Using a combination of experimental and theoretical approaches, we show how such patterns arise autonomously from reciprocal density-dependent activation of cellular motility between the two species, without the need of any preexisting positional or orientational cues. Moreover, by re-designing the interaction, the original out-of-phase spatial oscillation rhythm of the two populations can be accordingly turned into in-phase oscillations. The robustness and versatility of the underlying pattern-formation process suggest that it could both be generically encountered in nature, for instance in the complex bacterial ecosystems found in biofilms [14–16], and used to promote the mixing or demixing of active particles in a controlled way.

scholarly journals Robust and Scalable Angiogenesis Assay of Perfused 3D Human iPSC-Derived Endothelium for Anti-Angiogenic Drug Screening

2020 ◽  
Vol 21 (13) ◽  
pp. 4804
Author(s):  
Vincent van Duinen ◽  
Wendy Stam ◽  
Eva Mulder ◽  
Farbod Famili ◽  
Arie Reijerkerk ◽  
...  
Keyword(s):  
Drug Screening ◽  
Cell Formation ◽  
Cell Types ◽  
Culture Conditions ◽  
In Vitro Assays ◽  
Vegf Receptor ◽  
Screening Assay ◽  
Angiogenesis Assay

To advance pre-clinical vascular drug research, in vitro assays are needed that closely mimic the process of angiogenesis in vivo. Such assays should combine physiological relevant culture conditions with robustness and scalability to enable drug screening. We developed a perfused 3D angiogenesis assay that includes endothelial cells (ECs) from induced pluripotent stem cells (iPSC) and assessed its performance and suitability for anti-angiogenic drug screening. Angiogenic sprouting was compared with primary ECs and showed that the microvessels from iPSC-EC exhibit similar sprouting behavior, including tip cell formation, directional sprouting and lumen formation. Inhibition with sunitinib, a clinically used vascular endothelial growth factor (VEGF) receptor type 2 inhibitor, and 3-(3-pyridinyl)-1-(4-pyridinyl)-2-propen-1-one (3PO), a transient glycolysis inhibitor, both significantly reduced the sprouting of both iPSC-ECs and primary ECs, supporting that both cell types show VEGF gradient-driven angiogenic sprouting. The assay performance was quantified for sunitinib, yielding a minimal signal window of 11 and Z-factor of at least 0.75, both meeting the criteria to be used as screening assay. In conclusion, we have developed a robust and scalable assay that includes physiological relevant culture conditions and is amenable to screening of anti-angiogenic compounds.

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