Christopher Andrew Lemmon

Christopher Andrew Lemmon
Virginia Commonwealth University | VCU · Biomedical Engineering

PhD, Biomedical Engineering

About

55
Publications
4,194
Reads
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2,293
Citations
Citations since 2016
33 Research Items
990 Citations
2016201720182019202020212022050100150
2016201720182019202020212022050100150
2016201720182019202020212022050100150
2016201720182019202020212022050100150
Additional affiliations
May 2017 - May 2017
Virginia Commonwealth University
Position
  • Professor
January 2012 - present
Virginia Commonwealth University
Position
  • Professor (Assistant)
February 2008 - November 2011
Duke University Medical Center
Position
  • PostDoc Position
Education
August 2001 - February 2008
Johns Hopkins University
Field of study
  • Biomedical Engineering
August 1998 - June 2000
University of Wisconsin–Madison
Field of study
  • Mechanical Engineering
August 1992 - June 1996
Lehigh University
Field of study
  • Mechanical Engineering

Publications

Publications (55)
Article
Full-text available
The ability of cells to sense and respond to mechanical cues from the surrounding environment has been implicated as a key regulator of cell differentiation, migration, and proliferation. The extracellular matrix (ECM) is an oft-overlooked component of the interface between cells and their surroundings. Cells assemble soluble ECM proteins into inso...
Article
Epithelial-Mesenchymal Transition (EMT) is a dynamic process through which epithelial cells transdifferentiate from an epithelial phenotype into a mesenchymal phenotype. Previous studies have also demonstrated that both mechanical signaling and soluble growth factor signaling facilitate this process. One possible point of integration for mechanical...
Article
Full-text available
Cells respond to mechanical cues from the substrate to which they are attached. These mechanical cues drive cell migration, proliferation, differentiation, and survival. Previous studies have highlighted three specific mechanisms through which substrate stiffness directly alters cell function: increasing stiffness drives (1) larger contractile forc...
Article
Recent work has indicated that the shape and size of a cell can influence how a cell spreads, develops focal adhesions, and exerts forces on the substrate. However, it is unclear how cell shape regulates these events. Here we present a computational model that uses cell shape to predict the magnitude and direction of forces generated by cells. The...
Article
Interactions between cells and the surrounding matrix are critical to the development and engineering of tissues. We have investigated the role of cell-derived traction forces in the assembly of extracellular matrix using what we believe is a novel assay that allows for simultaneous measurement of traction forces and fibronectin fibril growth at di...
Article
Epithelial-mesenchymal transition (EMT) is a biological process that plays a central role in embryonic development, tissue regeneration, and cancer metastasis. Transforming growth factor-β (TGFβ) is a potent inducer of this cellular transition, comprised of transitions from an epithelial state to partial or hybrid EMT state(s), to a mesenchymal sta...
Article
Full-text available
Epithelial‐mesenchymal transition (EMT) is the transdifferentiation of epithelial cells to a mesenchymal phenotype, in which cells lose epithelial‐like cell–cell adhesions and gain mesenchymal‐like enhanced contractility and mobility. EMT is crucial for tissue regeneration and is also implicated in pathological conditions, such as cancer metastasis...
Article
Full-text available
Studies from the past two decades have demonstrated convincingly that cells are able to sense the mechanical properties of their surroundings. Cells make major decisions in response to this mechanosensation, including decisions regarding cell migration, proliferation, survival, and differentiation. The vast majority of these studies have focused on...
Article
Full-text available
The extracellular matrix (ECM) plays a key role as both structural scaffold and regulator of cell signal transduction in tissues. In times of ECM assembly and turnover, cells upregulate assembly of the ECM protein, fibronectin (FN). FN is assembled by cells into viscoelastic fibrils that can bind upward of 40 distinct growth factors and cytokines....
Preprint
The extracellular matrix (ECM) plays a key role as both structural scaffold and regulator of cell signal transduction in tissues. In times of ECM assembly and turnover, cells upregulate assembly of the ECM protein, fibronectin (FN). FN is assembled by cells into viscoelastic fibrils that can bind upward of 40 distinct growth factors and cytokines....
Article
Full-text available
Assembly of the extracellular matrix protein fibronectin (FN) into insoluble, viscoelastic fibrils is a critical step during embryonic development and wound healing; misregulation of FN fibril assembly has been implicated in many diseases, including fibrotic diseases and cancer. We have previously developed a computational model of FN fibril assemb...
Article
Epithelial–mesenchymal transition (EMT) is an essential biological process, also implicated in pathological settings such as cancer metastasis, in which epithelial cells transdifferentiate into mesenchymal cells. We devised an image analysis pipeline to distinguish between tissues comprised of epithelial and mesenchymal cells, based on extracted fe...
Preprint
Full-text available
Assembly of the extracellular matrix protein fibronectin (FN) into insoluble, viscoelastic fibrils is a critical step during embryonic development and wound healing; misregulation of FN fibril assembly has been implicated in many diseases, including fibrotic diseases and cancer. We have previously developed a computational model of FN fibril assemb...
Article
Full-text available
Substrate surface characteristics such as roughness, wettability and particle density are well-known contributors of a substrate's overall osteogenic potential. These characteristics are known to regulate cell mechanics as well as induce changes in cell stiffness, cell adhesions, and cytoskeletal structure. Pro-osteogenic particles, such as hydroxy...
Article
Full-text available
Epithelial cells form continuous sheets of cells that exist in tensional homeostasis. Homeostasis is maintained through cell-to-cell junctions that distribute tension and balance forces between cells and their underlying matrix. Disruption of tensional homeostasis can lead to epithelial-mesenchymal transition (EMT), a transdifferentiation process i...
Article
Full-text available
Epithelial-mesenchymal transition (EMT) is a fundamental biological process that plays a central role in embryonic development, tissue regeneration, and cancer metastasis. Transforming growth factor-β (TGFβ) is a potent inducer of this cellular transition, which is composed of transitions from an epithelial state to intermediate or partial EMT stat...
Article
Full-text available
Epithelial-Mesenchymal Transition (EMT) is a critical process in embryonic development in which epithelial cells undergo a transdifferentiation into mesenchymal cells. This process is essential for tissue patterning and organization, and it has also been implicated in a wide array of pathologies. While the intracellular signaling pathways that regu...
Preprint
Full-text available
Epithelial cells form continuous sheets of cells that exist in tensional homeostasis. Homeostasis is maintained through cell-to-cell adhesions that distribute tension and balance forces between cells and their underlying matrix. Disruption of tensional homeostasis can lead to Epithelial-Mesenchymal Transition (EMT), which is a transdifferentiation...
Preprint
Full-text available
Epithelial-mesenchymal transition (EMT) is a fundamental biological process that plays a central role in embryonic development, tissue regeneration, and cancer metastasis. Transforming growth factor- β (TGF β ) is a major and potent inducer of this cellular transition, which is comprised of transitions from an epithelial state to an intermediate or...
Article
Full-text available
Many methods exist for quantifying cellular traction forces, including traction force microscopy and microfabricated post arrays. However, these methodologies have limitations, including a requirement to remove cells to determine undeflected particle locations and the inability to quantify forces of cells with low cytoskeletal stiffness, respective...
Preprint
Many methods exist for quantifying cellular traction forces, including traction force microscopy and microfabricated post arrays. However, these methodologies have limitations, including a requirement to remove cells to determine undeflected particle locations and the inability to quantify forces of cells with low cytoskeletal stiffness, respective...
Article
Full-text available
The mechanism of assembly of the extracellular matrix protein fibronectin (FN) into elastic, insoluble fibrils is still poorly understood. FN fibrillogenesis requires cell-generated forces, which expose cryptic FN-FN binding sites buried in FN Type III domains. The number and location of cryptic binding sites have been debated, but experimental evi...
Article
To study fibronectin (FN) conformation and assembly, we generated several deletion mutants: FNΔI1-5, FNΔIII1-3, FNΔIII4-8 and FNΔIII11-14. A monomeric form, FNmono, which lacked the C-terminal dimerization region, was also created. FNtnA-D was generated by swapping FNIII domains 1-8 in FNΔIII11-14 with seven FNIII domains from tenascin-C. The confo...
Article
Full-text available
The nucleus of a cell has long been considered to be subject to mechanical force. Despite the observation that mechanical forces affect nuclear geometry and movement, how forces are applied onto the nucleus is not well understood. The nuclear LINC (linker of nucleoskeleton and cytoskeleton) complex has been hypothesized to be the critical structure...
Article
In vitro generation of three-dimensional (3D) biological tissues and organ-like structures is a promising strategy to study and closely model complex aspects of the molecular, cellular, and physiological interactions of tissue. In particular, in vitro 3D tissue modeling holds promises to further our understanding of breast development. Indeed, biol...
Article
Interactions between cells and the extracellular matrix (ECM) play a crucial role in regulating biological tissue function. Silk biomaterials from Bombyx mori (B. mori) silkworm silk are widely used in tissue engineering. As this silk fibroin (SF) contains no strong adhesion sites, we assessed whether the blending or coating of SF with collagen wou...
Article
Full-text available
Biologically relevant, three-dimensional extracellular matrix is an essential component of in vitro vasculogenesis models. WI-38 fibroblasts assemble a 3D matrix that induces endothelial tubulogenesis, but this model is challenged by fibroblast senescence and the inability to distinguish endothelial cell-derived matrix from matrix made by WI-38 fib...
Chapter
This chapter discusses the mechanical and signaling roles of one particular extracellular matrix (ECM) protein, fibronectin (FN). FN is a soluble protein that is found at high concentration in the blood plasma. FN assembly is required for collagen assembly, fibrillin assembly, and tenascin assembly, and as such, is crucial to successful tissue engi...
Article
Full-text available
Rac1 influences a multiplicity of vital cellular- and tissue-level control functions, making it an important candidate for targeted therapeutics. The activity of the Rho family member Cdc42 has been shown to be modulated by tyrosine phosphorylation at position 64. We therefore investigated consequences of the point mutations Y64F and Y64D in Rac1....
Article
Full-text available
Fibronectin (FN) is an extracellular matrix protein that is assembled into fibrils by cells during tissue morphogenesis and wound healing. FN matrix fibrils are highly elastic, but the mechanism of elasticity has been debated: it may be achieved by mechanical unfolding of FN-III domains or by a conformational change of the molecule without domain u...
Article
Full-text available
Protein S-nitrosation is a reversible post-translation modification critical for redox-sensitive cell signaling that is typically studied using the Biotin Switch method. This method and subsequent modifications usually require avidin binding or Western blot analysis to detect biotin labeled proteins. We describe here a modification of the Biotin Sw...
Article
Controlling the organization of proteins on surfaces provides a powerful biochemical tool for determining how cells interpret the spatial distribution of local signaling molecules. Here, we describe a general high fidelity approach based on electron beam writing to pattern the functional properties of protein-coated surfaces at length scales rangin...
Article
Full-text available
FAK, a cytoplasmic protein tyrosine kinase, is activated and localized to focal adhesions upon cell attachment to extracellular matrix. FAK null cells spread poorly and exhibit altered focal adhesion turnover. Rac1 is a member of the Rho-family GTPases that promotes membrane ruffling, leading edge extension, and cell spreading. We investigated the...
Article
Oxidized low-density lipoprotein (OxLDL) impairs NO signaling and endothelial function, and contributes to the pathogenesis of atherosclerosis. Arginase reciprocally regulates NO levels in endothelial cells by competing with NO synthase for the substrate l-arginine. In human aortic endothelial cells, OxLDL stimulation increased arginase enzyme acti...
Article
Full-text available
Focal adhesion kinase (FAK) transduces cell adhesion to the extracellular matrix into proliferative signals. We show that FAK overexpression induced proliferation in endothelial cells, which are normally growth arrested by limited adhesion. Interestingly, displacement of FAK from adhesions by using a FAK-/- cell line or by expressing the C-terminal...
Article
Full-text available
The interplay of mechanical forces between the extracellular environment and the cytoskeleton drives development, repair, and senescence in many tissues. Quantitative definition of these forces is a vital step in understanding cellular mechanosensing. Microfabricated post array detectors (mPADs) provide direct measurements of cell-generated forces...
Article
The alpha-1 adrenergic receptors (alpha(1)ARs) are critical in sympathetically mediated vasoconstriction. The specific role of each alpha(1)AR subtype in regulating vasoconstriction remains highly controversial. Limited pharmacological studies suggest that differential alpha(1)AR responses may be the result of differential activation of junctional...
Article
Subcellular localization of nitric oxide (NO) synthases with effector molecules is an important regulatory mechanism for NO signalling. In the heart, NO inhibits L-type Ca2+ channels but stimulates sarcoplasmic reticulum (SR) Ca2+ release, leading to variable effects on myocardial contractility. Here we show that spatial confinement of specific NO...
Article
Full-text available
An experimental and computational investigation was conducted on the film cooling adia-batic effectiveness of a flat plate with full coverage film cooling. The full coverage film cooling array was comprised of ten rows of coolant holes, arranged in a staggered pattern, with short L/D1, normal coolant holes. A single row of cooland holes was also ex...
Article
Typescript. Thesis (M.S.)--University of Wisconsin--Madison, 2000. Includes bibliographical references (leaves 182-184).

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