scholarly journals Martin Humphries: Attached to adhesion

2013 ◽  
Vol 200 (5) ◽  
pp. 554-555
Author(s):  
Caitlin Sedwick
Keyword(s):  
Extracellular Matrix ◽  
Cell Phenotype ◽  
Matrix Influence

Humphries studies how interactions with the extracellular matrix influence cell phenotype.

scholarly journals Age related extracellular matrix and interstitial cell phenotype in pulmonary valves

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Shaohua Wu ◽  
Vikas Kumar ◽  
Peng Xiao ◽  
Mitchell Kuss ◽  
Jung Yul Lim ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Extracellular Matrix ◽  
Heart Valve ◽  
Cell Phenotype ◽  
Primary Concern ◽  
Ross Operation ◽  
Age Related ◽  
Cardiovascular Morbidity And Mortality ◽  
Extracellular Matrix Components ◽  
Matrix Components

AbstractHeart valve disease is a common manifestation of cardiovascular disease and is a significant cause of cardiovascular morbidity and mortality worldwide. The pulmonary valve (PV) is of primary concern because of its involvement in common congenital heart defects, and the PV is usually the site for prosthetic replacement following a Ross operation. Although effects of age on valve matrix components and mechanical properties for aortic and mitral valves have been studied, very little is known about the age-related alterations that occur in the PV. In this study, we isolated PV leaflets from porcine hearts in different age groups (~ 4–6 months, denoted as young versus ~ 2 years, denoted as adult) and studied the effects of age on PV leaflet thickness, extracellular matrix components, and mechanical properties. We also conducted proteomics and RNA sequencing to investigate the global changes of PV leaflets and passage zero PV interstitial cells in their protein and gene levels. We found that the size, thickness, elastic modulus, and ultimate stress in both the radial and circumferential directions and the collagen of PV leaflets increased from young to adult age, while the ultimate strain and amount of glycosaminoglycans decreased when age increased. Young and adult PV had both similar and distinct protein and gene expression patterns that are related to their inherent physiological properties. These findings are important for us to better understand the physiological microenvironments of PV leaflet and valve cells for correctively engineering age-specific heart valve tissues.

Reconstituted Extracellular Matrix Improve Osteoblastic Differentiation onto Titanium Surfaces

2012 ◽  
Vol 706-709 ◽  
pp. 584-588
Author(s):  
Lia Rimondini ◽  
Federica Demarosi ◽  
Ismaela Foltran ◽  
Nadia Quirici
Keyword(s):  
Extracellular Matrix ◽  
Electrostatic Force ◽  
Biological Tissues ◽  
Osteoblastic Differentiation ◽  
Cell Phenotype ◽  
Tissue Engineering Scaffolds ◽  
Electrospinning Technique ◽  
Differentiation Potential ◽  
Oral Implants

Electrospinning technique is an efficient processing method to manufacture micro-and nanosized fibrous structures by electrostatic force for different applications. In biomaterial field, electrospinning technique has been successfully utilized to prepare new drug delivery materials and tissue engineering scaffolds. Fiber mats of biodegradable polymers having a diameter in the nanoto submicro-scale can be considered to mimic the nanofibrous structure of native extracellular matrix (ECM). Native extracellular matrix, constituted of proteins and polysaccharides improving cells growth in its nanofibrous porous structure, controls not only the cell phenotype, but the whole structure of the biological tissues. In the present study we investigated the effect of electrospun reconstituted collagen fibers onto metals for oral implants devices manufacturing as far as the osteoblastic differentiation potential of stem cells and cytofunctionality of osteoblasts in-vitro. The cells cultured onto titanium samples coated with ECM constituents showed faster osteoblastic differentiation and more efficient deposition of mineralized matrix in comparison with those onto uncoated substrates.

scholarly journals Effects of Extracellular Matrix on the Morphology and Behaviour of Rabbit Auricular Chondrocytes in Culture

2005 ◽  
Vol 2005 (4) ◽  
pp. 364-373 ◽  
Author(s):  
Vega Villar-Suárez ◽  
B. Colaço ◽  
I. Calles-Venal ◽  
I. G. Bravo ◽  
J. G. Fernández-Álvarez ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Type Ii Collagen ◽  
Cell Phenotype ◽  
Nodule Formation ◽  
Type Ii ◽  
Protein Extract ◽  
Positive Effects ◽  
Reticular Pattern ◽  
Chondrocyte Cultures ◽  
Plastic Surfaces

Isolated chondrocytes dedifferentiate to a fibroblast-like shape on plastic substrata and proliferate extensively, but rarely form nodules. However, when dissociation is not complete and some cartilage remnants are included in the culture, proliferation decreases and cells grow in a reticular pattern with numerous nodules, which occasionally form small cartilage-like fragments. In an attempt to reproduce this stable chondrogenic state, we added a cartilage protein extract, a sugar extract, and hyaluronan to the medium of previously dedifferentiated chondrocytes. When protein extract was added, many cartilaginous nodules appeared. Hyaluronan produced changes in cell phenotype and behaviour, but not nodule formation. Protein extract has positive effects on the differentiation of previously proliferated chondrocytes and permits nodule formation and the extensive production of type-II collagen. A comparison with incompletely dissociated chondrocyte cultures suggests that the presence of some living cells anchored to their natural extracellular matrix provides some important additional factors for the phenotypical stability of chondrocytes on plastic surfaces. In order to elucidate if it is possible that the incidence of apoptosis is related to the results, we also characterized the molecular traits of apoptosis.

scholarly journals Role of Extracellular Matrix in Development and Cancer Progression

2018 ◽  
Vol 19 (10) ◽  
pp. 3028 ◽  
Author(s):  
Cameron Walker ◽  
Elijah Mojares ◽  
Armando del Río Hernández
Keyword(s):  
Extracellular Matrix ◽  
Cancer Progression ◽  
Chemical Cues ◽  
Control Cell ◽  
Malignant Cell ◽  
Cell Phenotype ◽  
Cell Behaviour ◽  
Biophysical Forces ◽  
Key Drivers

The immense diversity of extracellular matrix (ECM) proteins confers distinct biochemical and biophysical properties that influence cell phenotype. The ECM is highly dynamic as it is constantly deposited, remodelled, and degraded during development until maturity to maintain tissue homeostasis. The ECM’s composition and organization are spatiotemporally regulated to control cell behaviour and differentiation, but dysregulation of ECM dynamics leads to the development of diseases such as cancer. The chemical cues presented by the ECM have been appreciated as key drivers for both development and cancer progression. However, the mechanical forces present due to the ECM have been largely ignored but recently recognized to play critical roles in disease progression and malignant cell behaviour. Here, we review the ways in which biophysical forces of the microenvironment influence biochemical regulation and cell phenotype during key stages of human development and cancer progression.

Reference Models for Mitral Valve Tissue Engineering Based on Valve Cell Phenotype and Extracellular Matrix Analysis

2006 ◽  
Vol 183 (1) ◽  
pp. 12-23 ◽  
Author(s):  
T.C. Flanagan ◽  
A. Black ◽  
M. O’Brien ◽  
T.J. Smith ◽  
A.S. Pandit
Keyword(s):  
Tissue Engineering ◽  
Extracellular Matrix ◽  
Mitral Valve ◽  
Matrix Analysis ◽  
Cell Phenotype ◽  
Reference Models ◽  
Valve Tissue

scholarly journals Modelling fibrillogenesis of collagen-mimetic molecules

2020 ◽  
Author(s):  
A. E. Hafner ◽  
N. G. Gyori ◽  
C. A. Bench ◽  
L. K. Davis ◽  
A. Šarić
Keyword(s):  
Extracellular Matrix ◽  
Electrostatic Interactions ◽  
Collagen Type ◽  
Collagen Type I ◽  
Coarse Grained ◽  
Cell Phenotype ◽  
Type I ◽  
Collagen Scaffolds ◽  
Crucial Component ◽  
Self Assembled

One of the most robust examples of self-assembly in living organisms is the formation of collagen architectures. Collagen type I molecules are a crucial component of the extracellular-matrix where they self-assemble into fibrils of well defined striped patterns. This striped fibrilar pattern is preserved across the animal kingdom and is important for the determination of cell phenotype, cell adhesion, and tissue regulation and signalling. The understanding of the physical processes that determine such a robust morphology of self-assembled collagen fibrils is currently almost completely missing. Here we develop a minimal coarse-grained computational model to identify the physical principles of the assembly of collagen-mimetic molecules. We find that screened electrostatic interactions can drive the formation of collagen-like filaments of well-defined striped morphologies. The fibril pattern is determined solely by the distribution of charges on the molecule and is robust to the changes in protein concentration, monomer rigidity, and environmental conditions. We show that the fibril pattern cannot be easily predicted from the interactions between two monomers, but is an emergent result of multi-body interactions. Our results can help address collagen remodelling in diseases and ageing, and guide the design of collagen scaffolds for biotechnological applications.Statement of SignificanceCollagen type I protein is the most abundant protein in mammals. It is a crucial component of the extracellular-matrix where it robustly self-assembles into fibrils of specific striped architectures that are crucial for the correct collagen function. The molecular features that determine such robust fibril architectures are currently not well understood. Here we develop a minimal coarse-grained model to connect the design of collagen-like molecules to the architecture of the resulting self-assembled fibrils. We find that the pattern of charged residues on the surface of molecules can drive the formation of collagen-like fibrils and fully control their architectures. Our findings can help understand changes in collagen architectures observed in diseases and guide the design of synthetic collagen scaffolds.

scholarly journals High-throughput microscopy reveals the impact of multifactorial environmental perturbations on colorectal cancer cell growth

GigaScience ◽  
2021 ◽  
Vol 10 (4) ◽  
Author(s):  
Chun-Te Chiang ◽  
Roy Lau ◽  
Ahmadreza Ghaffarizadeh ◽  
Matthew Brovold ◽  
Dipen Vyas ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Extracellular Matrix ◽  
Cell Growth ◽  
Tumor Microenvironment ◽  
Cancer Cell ◽  
Response To Therapy ◽  
Model Systems ◽  
Cell Phenotype ◽  
Environmental Perturbations ◽  
Drug Concentrations

Abstract Background Colorectal cancer (CRC) mortality is principally due to metastatic disease, with the most frequent organ of metastasis being the liver. Biochemical and mechanical factors residing in the tumor microenvironment are considered to play a pivotal role in metastatic growth and response to therapy. However, it is difficult to study the tumor microenvironment systematically owing to a lack of fully controlled model systems that can be investigated in rigorous detail. Results We present a quantitative imaging dataset of CRC cell growth dynamics influenced by in vivo–mimicking conditions. They consist of tumor cells grown in various biochemical and biomechanical microenvironmental contexts. These contexts include varying oxygen and drug concentrations, and growth on conventional stiff plastic, softer matrices, and bioengineered acellular liver extracellular matrix. Growth rate analyses under these conditions were performed via the cell phenotype digitizer (CellPD). Conclusions Our data indicate that the growth of highly aggressive HCT116 cells is affected by oxygen, substrate stiffness, and liver extracellular matrix. In addition, hypoxia has a protective effect against oxaliplatin-induced cytotoxicity on plastic and liver extracellular matrix. This expansive dataset of CRC cell growth measurements under in situ relevant environmental perturbations provides insights into critical tumor microenvironment features contributing to metastatic seeding and tumor growth. Such insights are essential to dynamical modeling and understanding the multicellular tumor-stroma dynamics that contribute to metastatic colonization. It also establishes a benchmark dataset for training and testing data-driven dynamical models of cancer cell lines and therapeutic response in a variety of microenvironmental conditions.

Context-dependent bioactivity of versican fragments

Glycobiology ◽  
2019 ◽  
Vol 30 (6) ◽  
pp. 365-373 ◽  
Author(s):  
Katherine Payne Timms ◽  
Sean Bertram Maurice
Keyword(s):  
Extracellular Matrix ◽  
Endothelial Cells ◽  
Cell Migration ◽  
Cleavage Site ◽  
Cell Phenotype ◽  
Ecm Remodeling ◽  
Cleavage Activity ◽  
Context Dependent ◽  
Proliferation And Invasion

Abstract Versican (VCAN) proteolysis and the accumulation of VCAN fragments occur in many developmental and disease processes, affecting extracellular matrix (ECM) structure and cell phenotype. Little is known about the significance of proteolysis and the roles of fragments, or how this ECM remodeling affects the microenvironment and phenotype of diseased cells. G1-DPEAAE fragments promote aspects of epithelial–mesenchymal transitioning in developing and diseased cells, resulting in cell migration. Enhanced proliferation and invasion of tumor and endothelial cells is directly associated with G1 domain deposition and G1-DPEAAE localization respectively. These tumorigenic and angiogenic roles could explain the disease exacerbating effect often associated with G1-containing fragments, however, the pathogenicity of G1 fragments depends entirely upon the context. Overall, VCAN fragments promote tumorigenesis and inflammation; however, the specific cleavage site, the extent of cleavage activity and the microenvironment in which cleavage occurs collectively determine how this pleiotropic molecule and its fragments influence cells.

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