Strain profiles for circular cell culture plates containing flexible surfaces employed to mechanically deform cells in vitro

Gilbert, John E.; Weinhold, Paul S.; Banes, Albert J.; Link, G.W.; Jones, G.L.

doi:10.1016/0021-9290(94)90057-4

Cited by 184 publications

(129 citation statements)

References 24 publications

Supporting

Mentioning

127

Contrasting

Unclassified

Order By: Relevance

“…The maximum strain distribution on the silicone membrane was not homogeneously induced. Gilbert et al (1994) compared the strain distribution between thick (the same membrane used in this study) and thin silicone membranes with the Flexercell Strain Unit (Flexcell International Corp., Hillsborough, NC, USA) using finite element methods. Based on their findings, it may be advantageous in future studies to use thin silicone membranes to create a relatively uniform strain.…”

Section: Discussionmentioning

confidence: 99%

Vibrational stimulation induces osteoblast differentiation and the upregulation of osteogenic gene expression in vitro

2016

View full text Add to dashboard Cite

Vibrational stimulation is an accepted non-invasive method used to improve bone remodeling. However, the underlying mechanisms of this phenomenon remain unclear. In this study, we developed a new vibration-loading system to apply vibrational stimulation to cells based on a previously reported in vivo study. We hypothesized that osteoblasts respond to vibrational strain by expressing osteogenic marker genes, such as alkaline-phosphatase (ALP), Runx2, and Osterix. To test our hypothesis, we developed a vibration-loading system to apply a precise vibrational force to an osteoblast culture on a silicone membrane. The system regulated frequency and acceleration of the vibration, and strain on the silicone membrane culture surface was measured using the strain gauge method. After vibrational stimulation, cellular gene expression was analyzed using real-time polymerase chain reaction. We obtained clear strain signals from the culture surface at vibrational ranges of 1.0-10 m/s 2 acceleration and frequencies of 30, 60, and 90 Hz, respectively. The strain increased in a linear fashion, depending on the acceleration magnitude. Vibrational stimulation also significantly upregulated expression of the osteogenic marker genes Runx2, Osterix, type I collagen, and ALP. In conclusion, we developed a new vibrationloading system that can precisely regulate frequency and acceleration, and we established the presence of dynamic cellular strain on a culture surface. Our findings suggest that vibrational stimulation may directly induce osteoblast differentiation.

show abstract

Section: Discussionmentioning

confidence: 99%

Vibrational stimulation induces osteoblast differentiation and the upregulation of osteogenic gene expression in vitro

2016

View full text Add to dashboard Cite

show abstract

“…In Vitro Cyclical Strain on ECs-The strain unit Flexcell FX-2000 (Flexcell, McKeesport, PA) consisted of a vacuum unit linked to a valve controlled by a computer program (25). Bovine aortic ECs cultured on a flexible membrane base were deformed by a sinusoidal negative pressure that produced an average strain of 12% at a frequency of 1 Hz.…”

Section: Methodsmentioning

confidence: 99%

Sequential Activation of Protein Kinase C (PKC)-α and PKC-ε Contributes to Sustained Raf/ERK1/2 Activation in Endothelial Cells under Mechanical Strain

Cheng

Wung

Chao

et al. 2001

Journal of Biological Chemistry

View full text Add to dashboard Cite

Endothelial cells (ECs) are constantly subjected to hemodynamic forces including cyclic pressure-induced strain. The role of protein kinase C (PKC) in cyclic strain-treated ECs was studied. PKC activities were induced as cyclic strain was initiated. Cyclic strain to ECs caused activation of PKC-␣ and -⑀. The translocation of PKC-␣ and -⑀ but not PKC-␤ from the cytosolic to membrane fraction was observed. An early transient activation of PKC-␣ versus a late but sustained activation of PKC-⑀ was shown after the onset of cyclic strain. Consistently, a sequential association of PKC-␣ and -⑀ with the signaling molecule Raf-1 was shown. ECs treated with a PKC inhibitor (calphostin C) abolished the cyclic strain-induced Raf-1 activation. ECs under cyclic strain induced a sustained activation of extracellular signalregulated protein kinases (ERK1/2), which was inhibited by treating ECs with calphostin C. ECs treated with a specific Ca 2؉ -dependent PKC inhibitor (Go 6976) showed an inhibition in the early phase of ERK1/2 activation but not in the late and sustained phase. ECs transfected with the antisense to PKC-␣, the antisense to PKC-⑀, or the inhibition peptide to PKC-⑀ reduced strain-induced ERK1/2 phosphorylation in a temporal manner. PKC-␣ mediated mainly the early ERK1/2 activation, whereas PKC-⑀ was involved in the sustained ERK1/2 activation. Strained ECs increased transcriptional activity of Elk1 (an ERK1/2 substrate). ECs transfected with the antisense to each PKC isoform reduced Elk1 and monocyte chemotactic protein-1 promotor activity. Our findings conclude that a sequential activation of PKC isoform (␣ and ⑀) contribute to Raf/ERK1/2 activation, and PKC-⑀ appears to play a key role in endothelial adaptation to hemodynamic environment.

show abstract

“…Biaxial systems apply large deformations in two dimensions, often by applying pressure to a silicone membrane fixed like a drumhead. The deformation in this case can be quite complex (53) and may vary over the culture surface. In the special case where pressure is applied by a large, flat indenter, deformations are equal in both the radial and tangential direction and the pattern is referred to as equibiaxial (54).…”

Section: Models Of Mechanical Stimulationmentioning

confidence: 99%

Mechanotransduction in skeletal muscle

Burkholder¹

2007

Front Biosci

110

View full text Add to dashboard Cite

Mechanical signals are critical to the development and maintenance of skeletal muscle, but the mechanisms that convert these shape changes to biochemical signals is not known. When a deformation is imposed on a muscle, changes in cellular and molecular conformations link the mechanical forces with biochemical signals, and the close integration of mechanical signals with electrical, metabolic, and hormonal signaling may disguise the aspect of the response that is specific to the mechanical forces. The mechanically induced conformational change may directly activate downstream signaling and may trigger messenger systems to activate signaling indirectly. Major effectors of mechanotransduction include the ubiquitous mitogen activated protein kinase (MAP) and phosphatidylinositol-3' kinase (PI-3K), which have well described receptor dependent cascades, but the chain of events leading from mechanical stimulation to biochemical cascade is not clear. This review will discuss the mechanics of biological deformation, loading of cellular and molecular structures, and some of the principal signaling mechanisms associated with mechanotransduction. KeywordsSkeletal muscle; mechanotransduction; stretch INTRODUCTIONThe detection and response to physical forces is essential to all cells, but is particularly relevant to those that play a fundamentally mechanical role. The primordial nature of the cellular interaction with the physical world suggests that its control should be highly regulated and specific, and that the response should integrate many aspects of cellular physiology. Pathways involved in detecting and producing forces in muscle overlap those involved in detecting nutrient availability (1,2), intracellular energy status (3,4), and oxidative status (5,6). The signaling pathways modulated by force, insulin and insulin-like growth factor I (IGF-I)(7), adenosine monophosphate (AMP) dependent kinase (AMPK) (8), reactive oxygen species (ROS) (9), and prostaglandins (PG) (10) seem intractably intertwined.The adaptations of skeletal muscle to mechanical signals have been widely described, and the interested reader is referred to several recent reviews (11)(12)(13)(14). The physiological increase in force generating capacity associated with activity, and the increase in flexibility associated with stretch, were recognized in antiquity, but the mechanisms by which those changes manifest are still unclear. The present intention is to consider the shape changes and forces associated with mechanical signals and juxtapose them with observed changes in biochemical signaling to determine what might contribute to the cellular perception of mechanical signals.Careful consideration of the mechanical environment is the first step to sort out that labyrinth of signaling. When one considers mechanisms by which the mechanical environment can be NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript sensed, it is common to think of "force" and "deformation" separately. Sometimes this distinction is legitimate, bu...

show abstract

Strain profiles for circular cell culture plates containing flexible surfaces employed to mechanically deform cells in vitro

Cited by 184 publications

References 24 publications

Vibrational stimulation induces osteoblast differentiation and the upregulation of osteogenic gene expression in vitro

Vibrational stimulation induces osteoblast differentiation and the upregulation of osteogenic gene expression in vitro

Sequential Activation of Protein Kinase C (PKC)-α and PKC-ε Contributes to Sustained Raf/ERK1/2 Activation in Endothelial Cells under Mechanical Strain

Mechanotransduction in skeletal muscle

Contact Info

Product

Resources

About