Study on the Effects of Type I Collagen Combined with Noncollagenous Proteins on Hydroxyapatite Formation in vitro using SPM and GIXD

2009 ◽  
Vol 1238 ◽  
Author(s):  
Xiaolan Ba ◽  
Elaine DiMasi ◽  
Miriam H Rafailovich

AbstractThe effects of the components of extracellular matrix on the bone formation and the kinetics of crystal growth of calcium phosphate have remained unknown. In this paper, we reported a method to investigate the role of Type I collagen and the interactions with other ECM proteins such as fibronectin and elastin during biomimic mineralization process in vitro. The early stage of mineralization was characterized by scanning probe microscopy (SPM) and shear modulation force microscopy (SMFM). The late stage of mineralization was investigated by synchrotron grazing incident x-ray diffraction (GIXD). The results demonstrate the cooperative interaction between type I collagen and noncollagenous proteins such as fibronectin or elastin could be essential for the biomineralization.

1984 ◽  
Vol 99 (2) ◽  
pp. 607-614 ◽  
Author(s):  
S W Whitson ◽  
W Harrison ◽  
M K Dunlap ◽  
D E Bowers ◽  
L W Fisher ◽  
...  

We isolated cells from both calvaria and the outer cortices of long bones from 3- to 5-mo bovine fetuses. The cells were identified as functional osteoblasts by indirect immunofluorescence using antibodies against three bone-specific, noncollagenous matrix proteins (osteonectin, the bone proteoglycan, and the bone sialoprotein) and against type 1 collagen. In separate experiments, confluent cultures of the cells were radiolabeled and shown to synthesize and secrete osteonectin, the bone proteoglycan and the bone sialoprotein by immunoprecipitation and fluorography of SDS polyacrylamide gels. Analysis of the radiolabeled collagens synthesized by the cultures showed that they produced predominantly (approximately 94%) type I collagen, with small amounts of types III and V collagens. In agreement with previous investigators who have employed the rodent bone cell system, we confirmed in bovine bone cells that (a) there was a typical cyclic AMP response to parathyroid hormone, (b) freshly isolated cells possessed high levels of alkaline phosphatase, which diminished during culture but returned to normal levels in mineralizing cultures, and (c) cells grown in the presence of ascorbic acid and beta-glycerophosphate rapidly produced and mineralized an extracellular matrix containing largely type I collagen. These results show that antibodies directed against bone-specific, noncollagenous proteins can be used to clearly identify bone cells in vitro.


2020 ◽  
Author(s):  
Mingxing Ouyang ◽  
Jiun-Yann Yu ◽  
Yenyu Chen ◽  
Linhong Deng ◽  
Chin-Lin Guo

AbstractIn vivo, cells are surrounded by extracellular matrix (ECM). To build organs from single cells, it is generally believed that ECM serves as a large-scale scaffold to coordinate cell positioning and differentiation. Nevertheless, how cells utilize cell-ECM interactions to spatiotemporally coordinate their positioning and differentiation to different ECM at the whole-tissue scale is not fully understood. Here, using in vitro assay with engineered MDCK cells co-expressing H2B-mCherry (nucleus) and gp135 (Podocalyxin)-GFP (apical marker), we show that such spatiotemporal coordination for epithelial morphogenesis and polarization can be initiated and determined by cell-soluble ECM interaction in the fluidic phase. The coordination depends on the native topology of ECM components such as sheet-like basement membrane (BM, mimicked by Matrigel in experiments) and linear fiber-like type I collagen (COL). Two types of coordination are found: scaffold formed by BM (COL) facilitates a close-ended (open-ended) coordination that leads to the formation of lobular (tubular) epithelium, where polarity is preserved throughout the entire lobule/tubule. During lobular formation with BM, polarization of individual cells within the same cluster occurs almost simultaneously, whereas the apicobasal polarization in the presence of COL can start at local regions and proceed in a collective way along the axis of tubule, which might suggest existence of intercellular communications at the cell-population level. Further, in the fluidic phase, we found that cells can form apicobasal polarity throughout the entire lobule/tubule without a complete coverage of ECM at the basal side. Based on reconstructions from time-lapse confocal imaging, this is likely derived from polarization occurring at early stage and being maintained through growth of the epithelial structures. Under suspension culture with COL, the polarization was impaired with formation of multi-lumens on the tubes, implying the importance of ECM microenvironment for tubulogenesis. Our results suggest a mechanism for cells to form polarity and coordinate positioning in vivo, and a strategy for engineering epithelial structures through cell-soluble ECM interaction and self-assembly in vitro.


2006 ◽  
Vol 1 (1) ◽  
pp. 61-72 ◽  
Author(s):  
Elena Oprita ◽  
Lucia Moldovan ◽  
Oana Craciunescu ◽  
Wanda Buzgariu ◽  
Christu Tardei ◽  
...  

AbstractCollagen-phosphate composites (COL/β-TCP) are novel materials that have the potential to be used as bone analogues. The aim of our study was to develop a porous bioactive material composed of type I collagen, the main bone protein and tricalcium phosphate, the mineral phase of natural bone, and investigate their in vitro biocompatibility in a human dermal fibroblast culture system. In order to obtain the bioactive materials, type I collagen was isolated from bovine tendon and characterized by physicochemical methods. β-TCP was obtained from calcium carbonate by thermal decomposition at 900 °C temperature. The powder was examined with X-ray diffraction. Two variants of COL/β-TCP scaffolds (P1 and P2) were prepared and examined by scanning electron microscopy. Our results revealed a microporous structure with small white aggregates of β-TCP, non-homogenous scattered in the collagen framework without any preferential orientation. The biocompatibility of the obtained scaffolds was tested by biochemical and histological methods on human fibroblast cultures. Both materials acted as good subtrates for human dermal fibroblast proliferation and migration.


2009 ◽  
Vol 21 (05) ◽  
pp. 311-316
Author(s):  
Yih-Pey Yang ◽  
Chia-Chi Lin

The interaction between cells and biomaterials strongly depends on the assembled structure of collagen adsorption upon the solid surface. Due to its self-assembling property, Type I collagen may aggregate and form fibrils in vivo and in vitro. This study utilizes an atomic force microscope to investigate nanometer-scale organization of adsorbed Type I collagen layers on mica and on poly(methyl methacrylate) (PMMA). We have observed various film morphologies, depending on substrate hydrophobicity and the state of collagen solution used. On mica, the atomic force microscopy (AFM) study obtains dense felt-like structures of randomly distributed assemblies. Images of network-like assemblies composed of interwoven fibrils appear on PMMA. According to the above results, we believe that these assemblies are associated at the interface rather than aggregated in the solution. This work also investigates the adsorbed collagen structure on PMMA after collagen aggregation in solution, to realize the relation between adsorption and aggregation. Consequently, the result exhibits a dendritic fibrillar structure adsorbed on PMMA, following collagen molecule aggregation, to form a fibrillar structure in the solution. This result suggests that the adsorption of aggregates preformed in the solution is preferable to collagen molecules adsorption. This research created all assembled structures of adsorbed collagen layers in nanometer-scale thickness.


Author(s):  
Nicola Alessio ◽  
Antonietta Stellavato ◽  
Domenico Aprile ◽  
Donatella Cimini ◽  
Valentina Vassallo ◽  
...  

Mesenchymal stromal cells (MSCs) are currently used for cartilage cell therapy because of their well proven capacity to differentiate in chondrocytes. The advantage of MSC-based therapy is the possibility of producing a high number of chondrocytes for implants. The transplant procedure, however, has some limitations, since MSCs may produce non-functional chondrocytes. This limit has been challenged by cultivating MSC in media with hydrogels containing hyaluronic acid (HA), extractive chondroitin sulfate (CS), or bio-fermentative unsulphated chondroitin (BC) alone or in combination. Nevertheless, a clear study of the effect of glycosaminoglycans (GAGs) on chondrocyte differentiation is still lacking, especially for the newly obtained unsulfated chondroitin of biotechnological origin. Are these GAGs playing a role in the commitment of stem cells to chondrocyte progenitors and in the differentiation of progenitors to mature chondrocytes? Alternatively, do they have a role only in one of these biological processes? We evaluated the role of HA, CS, and – above all – BC in cell commitment and chondrocyte differentiation of MSCs by supplementing these GAGs in different phases of in vitro cultivation. Our data provided evidence that a combination of HA and CS or of HA and BC supplemented during the terminal in vitro differentiation and not during cell commitment of MSCs improved chondrocytes differentiation without the presence of fibrosis (reduced expression of Type I collagen). This result suggests that a careful evaluation of extracellular cues for chondrocyte differentiation is fundamental to obtaining a proper maturation process.


Development ◽  
2002 ◽  
Vol 129 (17) ◽  
pp. 4045-4055 ◽  
Author(s):  
Georges Nemer ◽  
Mona Nemer

In vertebrates, heart development is a complex process requiring proper differentiation and interaction between myocardial and endocardial cells. Significant progress has been made in elucidating the molecular events underlying myocardial cell differentiation. In contrast, little is known about the development of the endocardial lineage that gives rise to cardiac valves and septa. We have used a novel in vitro model to identify the molecular hierarchy of endocardial differentiation and the role of transcription factor GATA5 in endocardial development. The results indicate that GATA5 is induced at an early stage of endothelial-endocardial differentiation prior to expression of such early endocardial markers as Tie2 and ErbB3. Inhibition of either GATA5 expression or NF-ATc activation, blocks terminal differentiation at a pre-endocardial stage and GATA5 and NF-ATc synergistically activate endocardial transcription. The data reveal that transcription factor GATA5 is required for differentiation of cardiogenic precursors into endothelial endocardial cells. This, in turn, suggests that the GATA5 pathway may be relevant to early stages of valvuloseptal development, defects of which account for the majority of human birth malformations.


1993 ◽  
Vol 106 (2) ◽  
pp. 503-511 ◽  
Author(s):  
A. Poliard ◽  
D. Lamblin ◽  
P.J. Marie ◽  
M.H. Buc-Caron ◽  
O. Kellermann

The mesodermal clone C1 was derived from the multipotent embryonal carcinoma 1003 cell line transformed with the plasmid pK4 carrying SV40 oncogenes under the control of the adenovirus E1A promoter. We have shown that the C1 clone becomes committed to the osteogenic pathway when cultured in aggregates in the presence of mediators of the osteogenic differentiation. To further validate C1 as a model with which to study osteogenesis in vitro the kinetics of its differentiation was studied, focusing on the histology of the aggregates and on the expression of a set of genes corresponding to representative bone matrix proteins. The presence of ascorbic acid and beta- glycerophosphate specifically leads to mineralization in almost 100% of the aggregates. Transcription of the above genes, silent in exponentially growing cells, specifically occurred with the establishment of cell-cell contacts independently of the presence of ascorbic acid and inorganic phosphate. The latter, however, were absolutely required for matrix deposition and mineralization. In their presence, one observed an overall decline in type I collagen and alkaline phosphatase transcripts while osteocalcin and osteopontin transcripts preferentially accumulated in cells lining the mineralizing foci. Concomitantly, type I collagen and osteocalcin became extracellularly deposited. The osteogenic differentiation of C1 occurred while cells were still proliferating. The C1 clone thus behaves as a mesodermal stem cell, becoming committed to the osteogenic pathway upon: firstly, establishment of cellular contacts; and secondly, addition of ascorbate and beta-glycerophosphate. It therefore appears to be a promising in vitro system for deciphering the molecular basis of osteoblast ontogeny.(ABSTRACT TRUNCATED AT 250 WORDS)


1987 ◽  
Vol 87 (3) ◽  
pp. 399-409
Author(s):  
R.J. Docherty ◽  
J.V. Forrester ◽  
J.M. Lackie

Epithelial cells cultured on type I collagen gels adopt a typical apical—basal polarity and undergo differentiation. We have compared the behaviour of chick embryo retinal pigmented epithelial (RPE) cells on collagen and on plastic with and without gelatin coats. RPE cell proliferation was similar on all three substrata, and post-confluent cultures exhibited multilayering. On plastic and gelatin-coated plastic, dome formation, typical of transporting epithelia, occurred. On type I collagen gels, however, dome formation did not occur, but rather invasion of the gel matrix by cords of epithelial cells took place. In contrast, invasive behaviour of the cells was markedly reduced on type IV coated collagen gels, particularly in the presence of laminin. These results illustrate the prominent role of the extracellular matrix on phenotypic expression by RPE cells and may represent a more general phenomenon.


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