The Experts below are selected from a list of 35673 Experts worldwide ranked by ideXlab platform
David Erlinge - One of the best experts on this subject based on the ideXlab platform.
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P2Y_2 receptor modulates shear stress-induced Cell Alignment and actin stress fibers in human umbilical vein endothelial Cells
Cellular and Molecular Life Sciences, 2017Co-Authors: Ramasri Sathanoori, Paulina Bryl-gorecka, Christa E. Müller, Gary A. Weisman, Björn Olde, David ErlingeAbstract:Endothelial Cells release ATP in response to fluid shear stress, which activates purinergic (P2) receptor-mediated signaling molecules including endothelial nitric oxide (eNOS), a regulator of vascular tone. While P2 receptor-mediated signaling in the vasculature is well studied, the role of P2Y_2 receptors in shear stress-associated endothelial Cell Alignment, cytoskeletal alterations, and wound repair remains ill defined. To address these aspects, human umbilical vein endothelial Cell (HUVEC) monolayers were cultured on gelatin-coated dishes and subjected to a shear stress of 1 Pa. HUVECs exposed to either P2Y_2 receptor antagonists or siRNA showed impaired fluid shear stress-induced Cell Alignment, and actin stress fiber formation as early as 6 h. Similarly, when compared to Cells expressing the P2Y_2 Arg-Gly-Asp (RGD) wild-type receptors, HUVECs transiently expressing the P2Y_2 Arg-Gly-Glu (RGE) mutant receptors showed reduced Cell Alignment and actin stress fiber formation in response to shear stress as well as to P2Y_2 receptor agonists in static cultures. Additionally, we observed reduced shear stress-induced phosphorylation of focal adhesion kinase (Y397), and cofilin-1 (S3) with receptor knockdown as well as in Cells expressing the P2Y_2 RGE mutant receptors. Consistent with the role of P2Y_2 receptors in vasodilation, receptor knockdown and overexpression of P2Y_2 RGE mutant receptors reduced shear stress-induced phosphorylation of AKT (S473), and eNOS (S1177). Furthermore, in a scratched wound assay, shear stress-induced Cell migration was reduced by both pharmacological inhibition and receptor knockdown. Together, our results suggest a novel role for P2Y_2 receptor in shear stress-induced cytoskeletal alterations in HUVECs.
Bauer E. Sumpio - One of the best experts on this subject based on the ideXlab platform.
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p38 Mitogen-activated protein kinase activation in endothelial Cell is implicated in Cell Alignment and elongation induced by fluid shear stress.
Endothelium : journal of endothelial cell research, 2006Co-Authors: Takayuki Kadohama, Nobuyuki Akasaka, Kengo Nishimura, Yuji Hoshino, Tadahiro Sasajima, Bauer E. SumpioAbstract:Fluid shear stress is thought to be important in maintaining the phenotype of endothelial Cells (ECs) in vivo. The purpose of the study was to determine the effect of varying levels of laminar shear stress on EC elongation and Alignment and the role of p38 mitogen-activated protein kinase (MAPK) on the morphologic change induced by shear stress. Cultured bovine aortic ECs were subjected to 1, 4, 7, 14, or 20 dyne/cm2 laminar steady shear stress. On morphometric analysis of static ECs, the average orientation angle was 41°, whereas after 24 h shear stress at 1, 4, 7, 14, and 20 dyne/cm2 the angles were 34°, 33°, 16°, 11°, and 10°, respectively. The shape index of static ECs was 0.76, whereas the indexes of ECs exposed to shear stress were 0.72, 0.72, 0.65, 0.50, and 0.47, respectively. The time and the magnitude of activation of p38 MAPK were dependent on the level of shear stress. The results indicate that a minimum shear stress of 7 to 14 dynes/cm2 is necessary for Cell Alignment and elongation and this ...
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Modulation of vascular smooth muscle Cell Alignment by cyclic strain is dependent on reactive oxygen species and P38 mitogen-activated protein kinase.
Journal of vascular surgery, 2003Co-Authors: Quanhai Chen, Zhiwei Quan, Bauer E. SumpioAbstract:Abstract Purpose: The aim of this study was to investigate the molecular targets of reactive oxygen species (ROS) and to determine whether cyclic strain induces smooth muscle Cell (SMC) Alignment via the ROS system. We assessed stretch-induced nicotinamide adenine dinucleotide phosphate (NAD(P)H) oxidase activation and the redox sensitivity of cyclic strain-stimulated activation of the mitogen-activated protein kinase (MAPK) family. Methods: SMCs were seeded on flexible collagen I-coated plates and exposed to cyclic strain. NAD(P)H oxidase activation was measured with lucigenin-enhanced chemiluminescent detection of superoxide. Activation of MAPK was detected by determining phosphorylation of extraCellular signal-regulated protein kinase (ERK1/2), c-jun N-terminal kinase (JNK1/2), and p38 MAPK with immunoblotting. In other experiments, SMCs were exposed to diphenylene iodonium (DPI), an NAD(P)H inhibitor, 30 minutes before stretch. MAPK activation and Cell orientation were then assessed. Results: Cyclic strain elicits a rapid increase in intraCellular NADH/NADPH oxidase in SMCs. There was also a rapid and robust phosphorylation of ERK1/2, JNK1/2, and p38 MAPK. Cyclic strain-induced intraCellular NAD(P)H generation was almost completely blocked with DPI. DPI also inhibited the strain-induced phosphorylation of ERK1/2, JNK1/2, and p38 MAPK. Both the p38 MAPK specific inhibitor, SB 202190, and DPI blocked cyclic strain-induced Cell Alignment, but PD98059, an ERK1/2-specific inhibitor, and SP600125, an anthrazolone inhibitor of JNK, did not. Conclusion: Our results provide evidence that p38 MAPK is a critical component of the oxidant stress ROS-sensitive signaling pathway and plays a crucial role in vascular Alignment induced by cyclic stain. (J Vasc Surg 2003;37:660-8.)
Helen M. Buettner - One of the best experts on this subject based on the ideXlab platform.
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Neurite Outgrowth is Directed by Schwann Cell Alignment in the Absence of Other Guidance Cues
Annals of biomedical engineering, 2006Co-Authors: Deanna M. Thompson, Helen M. BuettnerAbstract:Schwann Cells enhance axonal regeneration following nerve injury in vivo and provide a favorable substrate for neurite outgrowth in vitro. However, much remains unknown about the nature of interactions that occur between Schwann Cells and growing neurites. In this paper, we describe direct evidence of the ability of Schwann Cell Alignment alone to direct neurite outgrowth. Previously, we reported that laminin micropatterns can be used to align Schwann Cells and thus create oriented Schwann Cell monolayers. In the current study, dissociated rat spinal neurons were seeded onto oriented Schwann Cell monolayers, whose Alignment provided the only directional cue for growing neurites, and neurite Alignment with the underlying Schwann Cells was analyzed. The orientation of neurite outgrowth mimicked that of the Schwann Cells. Associations observed between neurites and Schwann Cells suggest that Schwann Cells may guide neurite outgrowth through both topographical and molecular mechanisms. This work demonstrates that Schwann Cell Alignment can direct neurite outgrowth in the absence of other directional cues, and provides a new method for examining neuronal–Schwann Cell interactions in vitro.
Alison P. Mcguigan - One of the best experts on this subject based on the ideXlab platform.
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A microgroove patterned multiwell Cell culture plate for high-throughput studies of Cell Alignment.
Biotechnology and bioengineering, 2014Co-Authors: Petra B. Lücker, Sahar Javaherian, John P. Soleas, Duncan Halverson, Peter W. Zandstra, Alison P. McguiganAbstract:Grooved substrates are commonly used to guide Cell Alignment and produce in vitro tissues that mimic certain aspects of in vivo Cellular organization. These more sophisticated tissues provide valuable in vitro models for testing drugs and for dissecting out molecular mechanisms that direct tissue organization. To increase the accessibility of these tissue models we describe a simple and yet reproducible strategy to produce 1 µm-spaced grooved well plates suitable for conducting automated analysis of Cellular responses. We characterize the Alignment of four human Cell types: retinal epithelial Cells, umbilical vein endothelial Cells, foreskin fibroblasts, and human pluripotent stem-Cell-derived cardiac Cells on grooves. We find all Cells align along the grooves to differing extents at both sparse and confluent densities. To increase the sophistication of in vitro tissue organization possible, we also created hybrid substrates with controlled patterns of microgrooved and flat regions that can be identified in real-time using optical microscopy. Using our hybrid patterned surfaces we explore: (i) the ability of neighboring Cells to provide a template to organize surrounding Cells that are not directly exposed to grooved topographic cues, and (ii) the distance over which this template effect can operate in confluent Cell sheets. We find that in fibroblast sheets, but not epithelial sheets, Cells aligned on grooves can direct Alignment of neighboring Cells in flat regions over a limited distance of approximately 200 μm. Our hybrid surface plate provides a novel tool for studying the collective response of groups of Cells exposed to differential topographical cues. Biotechnol. Bioeng. 2014;111: 2537–2548. © 2014 Wiley Periodicals, Inc.
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Multiwell plate tools for controlling Cellular Alignment with grooved topography.
Methods in molecular biology (Clifton N.J.), 2014Co-Authors: Camila Londono, Petra B. Lücker, John P. Soleas, Suthamathy Sathananthan, J. Stewart Aitchison, Alison P. McguiganAbstract:In many tissues, Cells must be aligned for proper function. This Alignment can occur at the Cellular and/or subCellular (protein/molecular) level. The Alignment of cytoskeletal components, in fact, precedes whole Cell Alignment. A variety of methods exist to manipulate cytoskeletal and whole Cell Alignment; one of the simplest and most predictable involves seeding adherent Cells onto defined substrate topography. We present here two methods to create grooved multiwell plates: one involving microfabrication, which allows for custom design of substrate topography, and a simpler, inexpensive method using commercially available diffraction gratings. We also include methods for manual and automatic quantification of Cell Alignment.
Klaus D Jandt - One of the best experts on this subject based on the ideXlab platform.
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stable extraCellular matrix protein patterns guide the orientation of osteoblast like Cells
Advanced Functional Materials, 2011Co-Authors: Jiantao Zhang, Mike Muhlstadt, Hilary Gallagher, Oliver Pullig, Klaus D JandtAbstract:The development of a simple method for creating extraCellular-matrix-protein patterns by microcontact printing to guide Cell organization and Alignment is reported. Substrates of glass and titanium are modified by a hydrophilic chitosan layer and then protein patterns with varying shapes and sizes are printed onto the surfaces. Confocal laser scanning microscopy shows that proteins (collagen type I, fibronectin, and gelatin) are accurately and effectively transferred from the stamp templates. These patterns are stable. Osteoblast-like Cells cultured on these micropatterned materials preferentially adhere and grow on the protein-functionalized areas. The Cell morphology and distribution direction are dependent on the widths and spaces of the protein patterns. It is possible to control the Cell Alignment by carefully designing the pattern shapes and sizes. This study suggests that the stable protein patterns can be used to modify biomaterials' surfaces and spatially control the organization of bone Cells. Due to the high stability, easy preparation procedure and the precise control of the Cell Alignment, the current work may provide opportunities for the surface modification of implantable materials, such as titanium for bone repair, where specific bone-Cell Alignment is needed.
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Stable ExtraCellular Matrix Protein Patterns Guide the Orientation of Osteoblast‐like Cells
Advanced Functional Materials, 2011Co-Authors: Jiantao Zhang, Mike Muhlstadt, Hilary Gallagher, Oliver Pullig, Juequan Nie, Klaus D JandtAbstract:The development of a simple method for creating extraCellular-matrix-protein patterns by microcontact printing to guide Cell organization and Alignment is reported. Substrates of glass and titanium are modified by a hydrophilic chitosan layer and then protein patterns with varying shapes and sizes are printed onto the surfaces. Confocal laser scanning microscopy shows that proteins (collagen type I, fibronectin, and gelatin) are accurately and effectively transferred from the stamp templates. These patterns are stable. Osteoblast-like Cells cultured on these micropatterned materials preferentially adhere and grow on the protein-functionalized areas. The Cell morphology and distribution direction are dependent on the widths and spaces of the protein patterns. It is possible to control the Cell Alignment by carefully designing the pattern shapes and sizes. This study suggests that the stable protein patterns can be used to modify biomaterials' surfaces and spatially control the organization of bone Cells. Due to the high stability, easy preparation procedure and the precise control of the Cell Alignment, the current work may provide opportunities for the surface modification of implantable materials, such as titanium for bone repair, where specific bone-Cell Alignment is needed.