Analysis of Orientations of Collagen Fibers by Novel Fiber-Tracking Software

2003 ◽  
Vol 9 (6) ◽  
pp. 574-580 ◽  
Author(s):  
Jun Wu ◽  
Bartłomiej Rajwa ◽  
David L. Filmer ◽  
Christoph M. Hoffmann ◽  
Bo Yuan ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Collagen Type I ◽  
Type I ◽  
Collagen Gels ◽  
Microscopy Imaging ◽  
Bovine Collagen ◽  
Confocal Images ◽  
Tracing Algorithm ◽  
Highly Correlated ◽  
Processing Techniques

Recent evidence supports the notion that biological functions of extracellular matrix (ECM) are highly correlated to not only its composition but also its structure. This article integrates confocal microscopy imaging and image-processing techniques to analyze the microstructural properties of ECM. This report describes a two- and three-dimensional fiber middle-line tracing algorithm that may be used to quantify collagen fibril organization. We utilized computer simulation and statistical analysis to validate the developed algorithm. These algorithms were applied to confocal images of collagen gels made with reconstituted bovine collagen type I, to demonstrate the computation of orientations of individual fibers.

Collagen Expression in Tissue Engineered Cartilage of Aged Human Articular Chondrocytes in a Rotating Bioreactor

2003 ◽  
Vol 26 (4) ◽  
pp. 319-330 ◽  
Author(s):  
S. Marlovits ◽  
B. Tichy ◽  
M. Truppe ◽  
D. Gruber ◽  
W. Schlegel
Keyword(s):  
Electron Microscopy ◽  
Collagen Type ◽  
Articular Chondrocytes ◽  
Three Dimensional ◽  
Collagen Type I ◽  
Human Articular Chondrocytes ◽  
Type I ◽  
Transmission Electron ◽  
Low Shear Stress ◽  
Engineered Cartilage

This study describes the culture and three-dimensional assembly of aged human articular chondrocytes under controlled oxygenation and low shear stress in a rotating-wall vessel. Chondrocytes cultured in monolayer were released and placed without any scaffold as a single cell suspension in a rotating bioreactor for 12 weeks. Samples were analyzed with immunohistochemistry, molecular biology and electron microscopy. During serial monolayer cultures chondrocytes dedifferentiated to a “fibroblast-like” structure and produced predominantly collagen type I. When these dedifferentiated cells were transferred to the rotating bioreactor, the cells showed a spontaneous aggregation and formation of solid tissue during the culture time. Expression of collagen type II and other components critical for the extracellular cartilage matrix could be detected. Transmission electron microscopy revealed a fine network of randomly distributed collagen fibrils. This rotating bioreactor proves to be a useful tool for providing an environment that enables dedifferentiated chondrocytes to redifferentiate and produce a cartilage-specific extracellular matrix.

scholarly journals Collagen microarchitecture mechanically controls myofibroblast differentiation

2020 ◽  
Vol 117 (21) ◽  
pp. 11387-11398 ◽  
Author(s):  
Bo Ri Seo ◽  
Xingyu Chen ◽  
Lu Ling ◽  
Young Hye Song ◽  
Adrian A. Shimpi ◽  
...  
Keyword(s):  
Collagen Type ◽  
Collagen Type I ◽  
Type I ◽  
Myofibroblast Differentiation ◽  
Dependent Manner ◽  
Fibrillar Collagen ◽  
Collagen Gels ◽  
Gelation Temperature ◽  
Rheological Characterization ◽  
Fiber Thickness

Altered microarchitecture of collagen type I is a hallmark of wound healing and cancer that is commonly attributed to myofibroblasts. However, it remains unknown which effect collagen microarchitecture has on myofibroblast differentiation. Here, we combined experimental and computational approaches to investigate the hypothesis that the microarchitecture of fibrillar collagen networks mechanically regulates myofibroblast differentiation of adipose stromal cells (ASCs) independent of bulk stiffness. Collagen gels with controlled fiber thickness and pore size were microfabricated by adjusting the gelation temperature while keeping their concentration constant. Rheological characterization and simulation data indicated that networks with thicker fibers and larger pores exhibited increased strain-stiffening relative to networks with thinner fibers and smaller pores. Accordingly, ASCs cultured in scaffolds with thicker fibers were more contractile, expressed myofibroblast markers, and deposited more extended fibronectin fibers. Consistent with elevated myofibroblast differentiation, ASCs in scaffolds with thicker fibers exhibited a more proangiogenic phenotype that promoted endothelial sprouting in a contractility-dependent manner. Our findings suggest that changes of collagen microarchitecture regulate myofibroblast differentiation and fibrosis independent of collagen quantity and bulk stiffness by locally modulating cellular mechanosignaling. These findings have implications for regenerative medicine and anticancer treatments.

scholarly journals In vitro production of human dermal equivalent

2010 ◽  
Vol 63 (7-8) ◽  
pp. 459-464 ◽  
Author(s):  
Zoran Milosavljevic ◽  
Biljana Ljujic
Keyword(s):  
Vitamin C ◽  
Collagen Type ◽  
Collagen Type I ◽  
Type I ◽  
Collagen Gels ◽  
In Vitro Production ◽  
Dermal Equivalent ◽  
Enzymatic Dissociation ◽  
Vitro Production

Introduction. Human dermal tissue is composed of loose and dense connective tissue. Main cell populations are fibroblasts and the dominant fibers are built from collagen type I. The aim of our study was to determine the precise method and time frame for the in vitro production of human dermal equivalent and to investigate the effects of ratio of structural elements and vitamin C on characteristics of the engineered tissue. Material and methods. Primary isolation of the foreskin fibroblasts was performed by explant method and enzymatic dissociation. Various collagen gels were obtained by mixing cells (from 25x103 to 200x103/ml) and neutralized collagen type I (from 2 to 4 mg/ml), with or without vitamin C. The routine histological and morphometrical examination was performed. Results. Enzymatic dissociation of the foreskin proved to be a faster method for production of desired number of fibroblasts (7.5x105 for 4 days). The contraction of collagen-gels started from day one through day seven and was dependent on cell and collagen concentration with higher density gels being contracted to a greater extent, except for the lowest/highest values. The best result was achieved with 100x103 cells and 2 mg/ml collagen. Vitamin C at 50 ?g/ml had no effect on speed of tissue formation. Conclusion. A precise approach that mimic the in vivo conditions is needed for the in vitro production of the dermal equivalent suitable for the possible treatment of tissue defects. Nearly ten days are necessary from the donor tissue dissociation to the final product.

Mesenchymal stem cells from adipose tissue which have been differentiated into chondrocytes in three-dimensional culture express lubricin

2011 ◽  
Vol 236 (11) ◽  
pp. 1333-1341 ◽  
Author(s):  
Giuseppe Musumeci ◽  
Debora Lo Furno ◽  
Carla Loreto ◽  
Rosario Giuffrida ◽  
Silvia Caggia ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Adipose Tissue ◽  
Collagen Type ◽  
Three Dimensional ◽  
3D Culture ◽  
Collagen Type I ◽  
Type I ◽  
Human Mscs ◽  
Alternative Source

The present study focused on the isolation, cultivation and characterization of human mesenchymal stem cells (MSCs) from adipose tissue and on their differentiation into chondrocytes through the NH ChondroDiff medium. The main aim was to investigate some markers of biomechanical quality of cartilage, such as lubricin, and collagen type I and II. Little is known, in fact, about the ability of chondrocytes from human MSCs of adipose tissue to generate lubricin in three-dimensional (3D) culture. Lubricin, a 227.5-kDa mucinous glycoprotein, is known to play an important role in articular joint physiology, and the loss of accumulation of lubricin is thought to play a role in the pathology of osteoarthritis. Adipose tissue is an alternative source for the isolation of multipotent MSCs, which allows them to be obtained by a less invasive method and in larger quantities than from other sources. These cells can be isolated from cosmetic liposuctions in large numbers and easily grown under standard tissue culture conditions. 3D chondrocytes were assessed by histology (hematoxylin and eosin) and histochemistry (Alcian blue and Safranin-O/fast green staining). Collagen type I, II and lubricin expression was determined through immunohistochemistry and Western blot. The results showed that, compared with control cartilage and monolayer chondrocytes showing just collagen type I, chondrocytes from MSCs (CD44-, CD90- and CD105- positive; CD45-, CD14- and CD34-negative) of adipose tissue grown in nodules were able to express lubricin, and collagen type I and II, indicative of hyaline cartilage formation. Based on the function of lubricin in the joint cavity and disease and as a potential therapeutic agent, our results suggest that MSCs from adipose tissue are a promising cell source for tissue engineering of cartilage. Our results suggest that chondrocyte nodules producing lubricin could be a novel biotherapeutic approach for the treatment of cartilage abnormalities.

scholarly journals Preliminary Study of In Vitro Three-Dimensional Skin Model Using an Ovine Collagen Type I Sponge Seeded with Co-Culture Skin Cells: Submerged versus Air-Liquid Interface Conditions

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2784
Author(s):  
Mh Busra Fauzi ◽  
Zahra Rashidbenam ◽  
Aminuddin Bin Saim ◽  
Ruszymah Binti Hj Idrus
Keyword(s):  
Collagen Type ◽  
Three Dimensional ◽  
Collagen Type I ◽  
Liquid Interface ◽  
Type I ◽  
Skin Model ◽  
Skin Cells ◽  
Air Liquid Interface ◽  
In Vitro Skin Model

Three-dimensional (3D) in vitro skin models have been widely used for cosmeceutical and pharmaceutical applications aiming to reduce animal use in experiment. This study investigate capability of ovine tendon collagen type I (OTC-I) sponge suitable platform for a 3D in vitro skin model using co-cultured skin cells (CC) containing human epidermal keratinocytes (HEK) and human dermal fibroblasts (HDF) under submerged (SM) and air-liquid interface (ALI) conditions. Briefly, the extracted OTC-I was freeze-dried and crosslinked with genipin (OTC-I_GNP) and carbodiimide (OTC-I_EDC). The gross appearance, physico-chemical characteristics, biocompatibility and growth profile of seeded skin cells were assessed. The light brown and white appearance for the OTC-I_GNP scaffold and other groups were observed, respectively. The OTC-I_GNP scaffold demonstrated the highest swelling ratio (~1885%) and water uptake (94.96 ± 0.14%). The Fourier transformation infrared demonstrated amide A, B and I, II and III which represent collagen type I. The microstructure of all fabricated sponges presented a similar surface roughness with the presence of visible collagen fibers and a heterogenous porous structure. The OTC-I_EDC scaffold was more toxic and showed the lowest cell attachment and proliferation as compared to other groups. The micrographic evaluation revealed that CC potentially formed the epidermal- and dermal-like layers in both SM and ALI that prominently observed with OTC-I_GNP compared to others. In conclusion, these results suggest that OTC_GNP could be used as a 3D in vitro skin model under ALI microenvironment.

scholarly journals Thrombospondin gene expression by endothelial cells in culture is modulated by cell proliferation, cell shape and the substratum

1990 ◽  
Vol 268 (1) ◽  
pp. 225-230 ◽  
Author(s):  
A E Canfield ◽  
R P Boot-Handford ◽  
A M Schor
Keyword(s):  
Gene Expression ◽  
Cell Proliferation ◽  
Endothelial Cells ◽  
Cell Shape ◽  
Type I Collagen ◽  
Three Dimensional ◽  
Type I ◽  
Mrna Levels ◽  
Collagen Gels ◽  
Cells Cultured

Endothelial cells plated on the surface of a two-dimensional substratum (gelatin-coated dishes, dishes coated with native type I collagen or collagen gels) form a cobblestone monolayer at confluence, whereas cells plated within a three-dimensional gel matrix elongate into a sprouting morphology and self-associate into tube-like structures. In this study, we have compared the synthesis of thrombospondin by quiescent endothelial cells displaying (a) the same morphological phenotype (cobblestone) on different substrata (gelatin and collagen) and (b) different morphological phenotypes (cobblestone and sprouting) on the same substratum (collagen). We demonstrate that thrombospondin is a major biosynthetic product of confluent, quiescent cells cultured on dishes coated with either gelatin or collagen, and that the synthesis of this protein is markedly decreased when cells are plated on or in three-dimensional collagen gels. Moreover, we demonstrate that cells plated in gel (sprouting) secrete less thrombospondin than do cells plated on the gel surface (cobblestone). The regulation of thrombospondin synthesis is reversible and occurs at the level of transcription, as steady-state mRNA levels for thrombospondin decrease in a manner comparable with the levels of protein secreted by these cells. We also show that mRNA levels for laminin B2 chains are increased when cells are cultured on and in collagen gels compared with on gelatin-coated dishes, suggesting that the syntheses of thrombospondin and laminin are regulated by different mechanisms. When cells are cultured on gelatin- or collagen-coated dishes, thrombospondin gene expression is directly proportional to the proliferative state of the cultures. By contrast, the synthesis of thrombospondin by cells cultured on collagen gels remains at equally low levels whether they are labelled when they are sparse and rapidly proliferating or when they are confluent and quiescent. Fibronectin synthesis was found to increase with increasing confluency of the cells plated on all three substrata. These results demonstrate that thrombospondin gene expression is modulated by cell shape, cell proliferation and the nature of the substratum used for cell culture.

scholarly journals Organotypic Cultures of Intervertebral Disc Cells: Responses to Growth Factors and Signaling Pathways Involved

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Harris Pratsinis ◽  
Dimitris Kletsas
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Intervertebral Disc ◽  
Dna Synthesis ◽  
Signaling Pathways ◽  
Collagen Type I ◽  
Cell Physiology ◽  
Type I ◽  
Collagen Gels

Intervertebral disc (IVD) degeneration is strongly associated with low back pain, a major cause of disability worldwide. An in-depth understanding of IVD cell physiology is required for the design of novel regenerative therapies. Accordingly, aim of this work was the study of IVD cell responses to mitogenic growth factors in a three-dimensional (3D) organotypic milieu, comprising characteristic molecules of IVD’s extracellular matrix. In particular, annulus fibrosus (AF) cells were cultured inside collagen type-I gels, while nucleus pulposus (NP) cells in chondroitin sulfate A (CSA) supplemented collagen gels, and the effects of Platelet-Derived Growth Factor (PDGF), basic Fibroblast Growth Factor (bFGF), and Insulin-Like Growth Factor-I (IGF-I) were assessed. All three growth factors stimulated DNA synthesis in both AF and NP 3D cell cultures, with potencies similar to those observed previously in monolayers. CSA supplementation inhibited basal DNA synthesis rates, without affecting the response to growth factors. ERK and Akt were found to be phosphorylated following growth factor stimulation. Blockade of these two signaling pathways using pharmacologic inhibitors significantly, though not completely, inhibited growth factor-induced DNA synthesis. The proposed culture systems may prove useful for further in vitro studies aiming at future interventions for IVD regeneration.

scholarly journals Pancreatic Cancer Cells Respond to Type I Collagen by Inducing Snail Expression to Promote Membrane Type 1 Matrix Metalloproteinase-dependent Collagen Invasion

2011 ◽  
Vol 286 (12) ◽  
pp. 10495-10504 ◽  
Author(s):  
Mario A. Shields ◽  
Surabhi Dangi-Garimella ◽  
Seth B. Krantz ◽  
David J. Bentrem ◽  
Hidayatullah G. Munshi
Keyword(s):  
Pancreatic Cancer ◽  
Cancer Cells ◽  
Type I Collagen ◽  
Epithelial Mesenchymal Transition ◽  
Three Dimensional ◽  
Type I ◽  
Collagen Gels ◽  
Mesenchymal Transition ◽  
Pancreatic Cancer Cells ◽  
Membrane Type

Pancreatic ductal adenocarcinoma (PDAC) is characterized by pronounced fibrotic reaction composed primarily of type I collagen. Although type I collagen functions as a barrier to invasion, pancreatic cancer cells have been shown to respond to type I collagen by becoming more motile and invasive. Because epithelial-mesenchymal transition is also associated with cancer invasion, we examined the extent to which collagen modulated the expression of Snail, a well known regulator of epithelial-mesenchymal transition. Relative to cells grown on tissue culture plastic, PDAC cells grown in three-dimensional collagen gels induced Snail. Inhibiting the activity or expression of the TGF-β type I receptor abrogated collagen-induced Snail. Downstream of the receptor, we showed that Smad3 and Smad4 were critical for the induction of Snail by collagen. In contrast, Smad2 or ERK1/2 was not involved in collagen-mediated Snail expression. Overexpression of Snail in PDAC cells resulted in a robust membrane type 1-matrix metalloproteinase (MT1-MMP, MMP-14)-dependent invasion through collagen-coated transwell chambers. Snail-expressing PDAC cells also demonstrated MT1-MMP-dependent scattering in three-dimensional collagen gels. Mechanistically, Snail increased the expression of MT1-MMP through activation of ERK-MAPK signaling, and inhibiting ERK signaling in Snail-expressing cells blocked two-dimensional collagen invasion and attenuated scattering in three-dimensional collagen. To provide in vivo support for our findings that Snail can regulate MT1-MMP, we examined the expression of Snail and MT1-MMP in human PDAC tumors and found a statistically significant positive correlation between MT1-MMP and Snail in these tumors. Overall, our data demonstrate that pancreatic cancer cells increase Snail on encountering collagen-rich milieu and suggest that the desmoplastic reaction actively contributes to PDAC progression.

Bacterial Endotoxin Inhibits Migration, Attachment, and Orientation of Human Gingival Fibroblasts in vitro and Delays Collagen Gel Contraction

1987 ◽  
Vol 66 (9) ◽  
pp. 1449-1455 ◽  
Author(s):  
S. Pitaru ◽  
M. Soldinger ◽  
D. Madgar ◽  
Z. Metzger
Keyword(s):  
Collagen Type ◽  
Cell Attachment ◽  
Collagen Gel ◽  
Collagen Type I ◽  
Human Gingival Fibroblasts ◽  
Bacterial Endotoxin ◽  
Type I ◽  
Gingival Fibroblasts ◽  
Collagen Gels

The purpose of this study was to assess the effect of endotoxin adsorbed to dental surfaces and to collagen type I on the migration, attachment, and orientation of human gingival fibroblasts (HGF). Transversely cut porcine tooth root slices (RS), 200 μm thick, were prepared. Half of the RS obtained were partially demineralized in EDTA. Half of the demineralized and non-demineralized RS were incubated with 400 μg/mL of endotoxin for 24 hr, whereas the other half were maintained in PBS and served as controls. Experimental and control RS were placed on confluent layers of HFG and cultured for six days. Cell migration toward and cell attachment to the periphery of the RS and the formation of oriented cell sheets were assessed by means of photographic techniques. Additionally, six-day-old cultures were fixed and processed for SEM observation. In separate experiments, the effect of endotoxin on cell attachment to collagen type I and on contraction of three-dimensional collagen gels was assessed. It was found that: (i) bacterial endotoxin inhibited migration and attachment of HGF to both demineralized and non-demineralized cementum and interfered with the development of oriented cellular structure ; (ii) the inhibitory effect was significantly more pronounced for non-demineralized than for demineralized cementum; (iii) the morphology of HGF attached to endotoxin-treated dental surfaces was altered compared with that of their controls; and (iv) bacterial endotoxin inhibited cell attachment to collagen type I and delayed the contraction of collagen gel.

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