Application of a Flow-Induced Stress Wave and Investigation of Associated Injuries on Cell Monolayers Using a Parallel Plate Flow Chamber

Parallel plate flow chambers are widely used to expose cultured cells to physiological flows for the investigation of a variety of diseases. These applications usually involve the generation of continuous and steady fluid flow over cell monolayers for extended durations, usually a few days. Another technique is to generate a fast high-stress wave over the cells to see the immediate effect of flow-induced stresses. This can be achieved by propagating an air/liquid interface, in other words, a bubble, over cell monolayers. The approach is relevant to the reopening event of fluid-filled lung bronchioles and alveoli during mechanical ventilation therapy of Acute Respiratory Distress Syndrome. This article explains how we generate a stress wave using a parallel plate flow chamber and presents representative results of this wave on cultured lung epithelial cells.

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Effect of Alpha-1 Antitrypsin on CFTR Levels in Primary Human Airway Epithelial Cells Grown at the Air-Liquid-Interface

Molecules ◽

10.3390/molecules26092639 ◽

2021 ◽

Vol 26 (9) ◽

pp. 2639

Author(s):

Frauke Stanke ◽

Sabina Janciauskiene ◽

Stephanie Tamm ◽

Sabine Wrenger ◽

Ellen Luise Raddatz ◽

...

Keyword(s):

Epithelial Cells ◽

Human Lung ◽

Liquid Interface ◽

Lung Epithelial Cells ◽

Western Blots ◽

Mesenchymal Transition ◽

Protein Levels ◽

Lung Epithelial ◽

Cftr Protein ◽

Air Liquid Interface

The cystic fibrosis transmembrane conductance regulator (CFTR) gene is influenced by the fundamental cellular processes like epithelial differentiation/polarization, regeneration and epithelial–mesenchymal transition. Defects in CFTR protein levels and/or function lead to decreased airway surface liquid layer facilitating microbial colonization and inflammation. The SERPINA1 gene, encoding alpha1-antitrypsin (AAT) protein, is one of the genes implicated in CF, however it remains unknown whether AAT has any influence on CFTR levels. In this study we assessed CFTR protein levels in primary human lung epithelial cells grown at the air-liquid-interface (ALI) alone or pre-incubated with AAT by Western blots and immunohistochemistry. Histological analysis of ALI inserts revealed CFTR- and AAT-positive cells but no AAT-CFTR co-localization. When 0.5 mg/mL of AAT was added to apical or basolateral compartments of pro-inflammatory activated ALI cultures, CFTR levels increased relative to activated ALIs. This finding suggests that AAT is CFTR-modulating protein, albeit its effects may depend on the concentration and the route of administration. Human lung epithelial ALI cultures provide a useful tool for studies in detail how AAT or other pharmaceuticals affect the levels and activity of CFTR.

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VCAM-1 is more effective than MAdCAM-1 in supporting eosinophil rolling under conditions of shear flow

Blood ◽

10.1182/blood.v95.2.592 ◽

2000 ◽

Vol 95 (2) ◽

pp. 592-601 ◽

Cited By ~ 41

Author(s):

P. Sriramarao ◽

Richard G. DiScipio ◽

Ronald R. Cobb ◽

Myron Cybulsky ◽

Greg Stachnick ◽

...

Keyword(s):

Monoclonal Antibody ◽

Parallel Plate ◽

Cell Adhesion Molecule ◽

Flow Chamber ◽

Β1 Integrin ◽

Vascular Cell Adhesion ◽

Parallel Plate Flow Chamber ◽

Vascular Cell

The ability of the 4 integrin counterligands vascular cell adhesion molecule (VCAM)-1 or mucosal addressin (MAd)CAM-1 to support eosinophil rolling or firm adhesion under conditions of physiologic flow has not been delineated. Using a parallel plate flow chamber in vitro and intravital microscopy in vivo, we demonstrate that eosinophil rolling and adhesion on VCAM-1 is mediated by both 4β1 and 4β7 integrins. Eosinophils rolled equally efficiently on both VCAM-1 2 domain and VCAM-1 7 domain, suggesting that the N-terminal 2 domains of VCAM-1 are sufficient to support eosinophil rolling under conditions of flow. Furthermore, activation of the eosinophil β1 integrin with monoclonal antibody (mAb) 8A2 resulted in both resistance to shear stress–induced detachment from VCAM-1 in vitro and in stable arrest of rolling eosinophils on interleukin (IL)-1β–stimulated venules in vivo. Eosinophils rolled less efficiently on MAdCAM-1– than on VCAM-1–coated coverslips under conditions of flow. However, eosinophils firmly adhered as efficiently to MAdCAM-1 as to VCAM-1. Overall, these results demonstrate that both VCAM-1 and MAdCAM-1 can support eosinophil firm adhesion under conditions of flow. In contrast, VCAM-1 is significantly more efficient than MAdCAM-1 in supporting eosinophil rolling under conditions of flow.

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Wall Shear Stress Determination in a Small-Scale Parallel Plate Flow Chamber Using Laser Doppler Velocimetry Under Laminar, Pulsatile and Low-Reynolds Number Turbulent Flows

Journal of Fluids Engineering ◽

10.1115/1.4039158 ◽

2018 ◽

Vol 140 (6) ◽

Cited By ~ 1

Author(s):

Hamed Avari ◽

Kem A. Rogers ◽

Eric Savory

Keyword(s):

Shear Stress ◽

Wall Shear Stress ◽

Laser Doppler Velocimetry ◽

Parallel Plate ◽

Flow Chamber ◽

Laser Doppler ◽

Small Scale ◽

Doppler Velocimetry ◽

Flow Conditions ◽

Parallel Plate Flow Chamber

The parallel plate flow chamber (PPFC) has gained popularity due to its applications in fields such as biological tissue engineering. However, most of the studies using PPFC refer to theoretical relations for estimating the wall shear stress (WSS) and, hence, the accuracy of such quantifications remains elusive for anything other than steady laminar flow. In the current study, a laser Doppler velocimetry (LDV) method was used to quantify the flow in a PPFC (H = 1.8 mm × W = 17.5 mm, Dh = 3.26 mm, aspect ratio = 9.72) under steady Re = 990, laminar pulsatile (carotid Re0-mean = 282 as well as a non-zero-mean sinusoidal Re0-mean = 45 pulse) and low-Re turbulent Re = 2750 flow conditions. A mini-LDV probe was applied, and the absolute location of the LDV measuring volume with the respect to the wall was determined using a signal monitoring technique with uncertainties being around ±27 μm. The uniformity of the flow across the span of the channel, as well as the WSS assessment for all the flow conditions, was measured with the uncertainties all being less than 16%. At least two points within the viscous sublayer of the low-Re turbulent flow were measured (with the y+ for the first point < 3) and the WSS was determined using two methods with the differences between the two methods being within 5%. This paper for the first time presents the experimental determination of WSS using LDV in a small-scale PPFC under various flow conditions, the challenges associated with each condition, and a comparison between the cases. The present data will be useful for those conducting biological or numerical modeling studies using such devices.

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