Impact of Variations in Water Concentration on the Nanomechanical Behaviour of Type I Collagen Microfibrils in Annulus Fibrosus

2021 ◽  
Author(s):  
Shambo Bhattacharya ◽  
Devendra Kumar Dubey
Keyword(s):  
Elastic Modulus ◽  
Annulus Fibrosus ◽  
Type I Collagen ◽  
Water Concentration ◽  
Collagen Type I ◽  
Type I ◽  
Load Bearing ◽  
Characteristic Features ◽  
Dynamics Simulations ◽  
Bearing Characteristic

Abstract Changes in water concentration mediated by proteoglycan degradation are characteristic features of intervertebral disc (IVD) degeneration. Change in water concentration alters the chemo-mechanical interactions among the nanoscale biomolecular constituents, affecting the load-bearing property of IVD. Present study investigates the effect of water concentration on the nanomechanics of collagen type I microfibrils in the Annulus Fibrosus using molecular dynamics simulations. Results show, in axial tension, increase in water concentration (WC) from 0% to ~50% increases the elastic modulus from ~2.7 GPa to ~4 GPa. This is attributed to a combination of a shift in deformation from backbone straightening to combined stretching and intermolecular sliding and subsequent strengthening of tropocollagen-water-tropocollagen (TWT) interface by the formation of water bridges and intermolecular electrostatic attractions. Further increase in WC to ~75% reduces the modulus to ~1.8 GPa due to shift in deformation to polypeptide straightening, weakening TWT interface due to reduced electrostatic attraction and increase in number of water molecules in a water bridge. During axial compression, increase in WC to ~50% results in increase in modulus from ~0.8 GPa to ~4.5 GPa. This is attributed to combination of the development of hydrostatic pressure and strengthening of the TWT interface. Further increase in WC to ~75% shifts the load-bearing characteristic from collagen to water, resulting in a decrease in elastic modulus to ~2.8 GPa. Such water-mediated alteration in load-bearing properties act as foundations to hypermobility or stiffening observed in degenerated spine segments.

scholarly journals Relative rates of biosynthesis of collagen type I, type V and type VI in calf cornea

1991 ◽  
Vol 274 (2) ◽  
pp. 615-617 ◽  
Author(s):  
P Kern ◽  
M Menasche ◽  
L Robert
Keyword(s):  
Type I Collagen ◽  
Collagen Type ◽  
Corneal Stroma ◽  
Collagen Type I ◽  
Type I ◽  
Type Vi Collagen ◽  
Sds Page ◽  
Proline Incorporation ◽  
Type V

The biosynthesis of type I, type V and type VI collagens was studied by incubation of calf corneas in vitro with [3H]proline as a marker. Pepsin-solubilized collagen types were isolated by salt fractionation and quantified by SDS/PAGE. Expressed as proportions of the total hydroxyproline solubilized, corneal stroma comprised 75% type I, 8% type V and 17% type VI collagen. The rates of [3H]proline incorporation, linear up to 24 h for each collagen type, were highest for type VI collagen and lowest for type I collagen. From pulse-chase experiments, the calculated apparent half-lives for types I, V and VI collagens were 36 h, 10 h and 6 h respectively.

Cartilage Regeneration with Cell-free Type 1 Collagen Matrix – Past, Present and Future (Part 1 – Clinical Aspects)

2020 ◽  
Author(s):  
Philip Peter Roessler ◽  
Turgay Efe ◽  
Dieter Christian Wirtz ◽  
Frank Alexander Schildberg
Keyword(s):  
Type I Collagen ◽  
Case Series ◽  
Cartilage Regeneration ◽  
Collagen Matrix ◽  
Treatment Method ◽  
Collagen Type I ◽  
Legal Framework ◽  
Clinical Aspects ◽  
Type I ◽  
Collagen Hydrogel

AbstractCartilage regeneration with cell-free matrices has developed from matrix-associated autologous cartilage cell transplantation (MACT) over ten years ago. Adjustments to the legal framework and higher hurdles for cell therapy have led to the procedures being established as an independent alternative to MACT. These procedures, which can be classified as matrix-induced autologous cartilage regeneration (MACR), all rely on the chemotactic stimulus of a cross-linked matrix, which mostly consists of collagens. Given the example of a commercially available type I collagen hydrogel, the state of clinical experience with MACR shall be summarized and an outlook on the development of the method shall be provided. It has been demonstrated in the clinical case series summarized here over the past few years that the use of the matrix is not only safe but also yields good clinical-functional and MR-tomographic results for both small (~ 10 mm) and large (> 10 mm) focal cartilage lesions. Depending on the size of the defect, MACR with a collagen type I matrix plays an important role as an alternative treatment method, in direct competition with both: microfracture and MACT.

scholarly journals Genetic and physiological variation in two strains of Japanese quail

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Nashat Saeid Ibrahim ◽  
Mohammed Ahmed El-Sayed ◽  
Heba Abdelwahab Mahmoud Assi ◽  
Ahmed Enab ◽  
Abdel-Moneim Eid Abdel-Moneim
Keyword(s):  
Japanese Quail ◽  
Type I Collagen ◽  
Collagen Type ◽  
Pectoral Muscle ◽  
Collagen Type I ◽  
Scientific Basis ◽  
Type I ◽  
Improvement Program ◽  
Body Weights ◽  
Physiological Variations

Abstract Background Detecting the genetic and physiological variations in two Japanese quail strains could be used to suggest a new avian model for future breeding studies. Consequently, two estimations were performed on two Japanese quail strains: gray quail strain (GJQS) and white jumbo quail strain (WJQS). The first estimation was conducted on carcass characteristics, breast muscles, breast concentration of collagen type I, and body measurements. In contrast, blood samples were collected for the second estimation for genomic DNA extraction and genetic analysis. Results A total of 62 alleles out of 97 specific alleles (63.92%) were detected overall loci (14 microsatellite loci) for the two strains. A total of 27 specific alleles of WJQS were observed, and 35 were obtained for GJQS. The percentage of similarity was 48.09% ranged from 4.35 with UBC001 to 100% with GUJ0051. WJQS had greater body weights and a higher value of pectoral muscle and supracoracoideus muscle than GJQS. The breast muscles of GJQS exhibited a higher concentration of type I collagen than the WJQS. Furthermore, males showed higher concentrations of collagen type I than females. WJQS showed a higher body length, chest girth, chest length, thigh length, thigh girth, drumstick length, and drumstick girth (cm) than GJQS. WJQS showed more significant differences in carcass traits compared with GJQS. Conclusion The physiological differences between WJQS and GJQS were ascertained with microsatellite markers, which indicated high polymorphism between these strains. These observations provided a scientific basis for evaluating and utilizing the genetic resources of WJQS and GJQS in a future genetic improvement program.

scholarly journals SAT0298 IS INTERLEUKIN 6 A FACTOR OF FIBROGENESIS IN DERMAL FIBROBLASTS?

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1094.1-1094
Author(s):  
A. S. Siebuhr ◽  
P. Juhl ◽  
M. Karsdal ◽  
A. C. Bay-Jensen
Keyword(s):  
Gene Expression ◽  
Type I Collagen ◽  
Collagen Type ◽  
Collagen Type I ◽  
Dermal Fibroblasts ◽  
Type I ◽  
Dependent Manner ◽  
Full Time ◽  
Collagen Formation ◽  
Type Iii

Background:Interleukin 6 (IL-6) is known to have both pro- and anti-inflammatory properties, depending on the receptor activation. The classical IL-6 signaling via the membrane bound receptor is mainly anti-inflammatory, whereas signaling through the soluble receptor (sIL-6R) is pro-inflammatory/pro-fibrotic. However, the direct fibrotic effect of IL-6 stimulation on dermal fibroblasts is unknown.Objectives:We investigated the fibrotic effect of IL-6 + sIL-6R in a dermal fibroblast model and assessed fibrosis by neo-epitope biomarkers of extracellular matrix proteins.Methods:Primary healthy human dermal fibroblasts were grown for up to 17 days in DMEM medium with 0.4% fetal calf serum, ficoll (to produce a crowded environment) and ascorbic acid. IL-6 [1-90 nM]+sIL-6R [0.1-9 nM] alone or in combination with TGFβ [1 nM] were tested in three different donors. TGFβ [1 nM], PDGF-AB [3 nM] and non-stimulated cells (w/o) were used as controls. Tocilizumab (TCZ) with TGFβ + IL-6 + sIL-6R stimulation was tested in one donor. Collagen type I, III and VI formation (PRO-C1, PRO-C3 and PRO-C6) and fibronectin (FBN-C) were evaluated by validated ELISAs (Nordic Bioscience). Western blot analysis investigated signal cascades. Gene expression of selected ECM proteins was analyzed. Statistical analyses included One-way and 2-way ANOVA and area under the curve analysis.Results:formation by the end of the culture period. The fibronectin and collagen type VI signal were consistent between the three tested donors, whereas the formation of type III collagen was only increased in one donor, but in several trials. Type I collagen formation was unchanged by IL-6 + sIL-6R stimulation. The gene expression of type I collagen was induced by IL-6 + sIL-6R. Western blot analysis validated trans-signaling by the IL-6+sIL-6R stimulation as expected.IL-6 + sIL-6R stimulation in combination with TGFβ decreased fibronectin levels compared to TGFβ alone but did not reach the level of unstimulated fibroblasts. The formation of collagen type IV was generally unchanged with IL-6 + sIL-6R + TGFβ compared to TGFβ alone. Collagen type I and III formation was more scattered in the signals when IL-6 + sIL-6R was in combination with TGFβ, as the biomarker level could be either decreased or increased compared to TGFβ alone. In two studies the type I collagen level was synergistic increased by IL-6 + sIL-6R + TGFβ, whereas another study found the level to be decreased compared to TGFβ alone. The gene expression of fibronectin and type I collagen was increased with TGFβ +IL-6+sIL-6R compared to TGFβ alone.Inhibition of IL-6R by TCZ in combination with IL-6 + sIL-6R did only decrease the fibronectin level with the lowest TCZ concentration (p=0.03). TCZ alone decreased the fibronectin level in a dose-dependent manner (One-way ANOVA p=0.0002).Conclusion:We investigated the fibrotic response of dermal fibroblasts to IL-6 + sIL-6R stimulation. IL-6 modulated the fibronectin level and modulated the collagen type III formation level in a somewhat dose-dependent manner. In combination with TGFβ, IL-6 decreased collagen type I and IV formation and fibronectin. However, in this study inhibition of IL-6R by TCZ did not change the fibrotic response of the dermal fibroblasts. This study indicated that IL-6 did not induce collagen formation in dermal fibroblasts, except type III collagen formation with high IL-6 concentration.Figure:Disclosure of Interests:Anne Sofie Siebuhr Employee of: Nordic Bioscience, Pernille Juhl Employee of: Nordic Bioscience, Morten Karsdal Shareholder of: Nordic Bioscience A/S., Employee of: Full time employee at Nordic Bioscience A/S., Anne-Christine Bay-Jensen Shareholder of: Nordic Bioscience A/S, Employee of: Full time employee at Nordic Bioscience A/S.

scholarly journals Measurement of Elastic Modulus of Collagen Type I Single Fiber

PLoS ONE ◽  
2016 ◽  
Vol 11 (1) ◽  
pp. e0145711 ◽  
Author(s):  
Pavel Dutov ◽  
Olga Antipova ◽  
Sameer Varma ◽  
Joseph P. R. O. Orgel ◽  
Jay D. Schieber
Keyword(s):  
Elastic Modulus ◽  
Collagen Type ◽  
Collagen Type I ◽  
Single Fiber ◽  
Type I

scholarly journals Endothelial cell growth factor and heparin regulate collagen gene expression in keloid fibroblasts

1991 ◽  
Vol 278 (3) ◽  
pp. 863-869 ◽  
Author(s):  
E M L Tan ◽  
J Peltonen
Keyword(s):  
Gene Expression ◽  
Endothelial Cell ◽  
Collagen Synthesis ◽  
Type I Collagen ◽  
Collagen Type ◽  
Collagen Type I ◽  
Type I ◽  
Collagen Gene ◽  
Endothelial Cell Growth Factor ◽  
Endothelial Cell Growth

Keloids are benign cutaneous tumours characterized by excess deposition of collagen, specifically type I collagen. We report here that collagen biosynthesis, as measured by hydroxyproline synthesis, was markedly inhibited by 65-80% by the combination of endothelial cell growth factor (ECGF) supplement and heparin in keloid fibroblast cultures. Fibroblast cultures that were incubated with ECGF alone also demonstrated a measurable decrease of approx. 50% in collagen synthesis compared with control cultures. The inhibition of collagen synthesis was related to the down-regulation of collagen gene expression. Quantitative measurements of mRNA-cDNA hybrids revealed that the gene expression of collagen type I was decreased by more than 80% by heparin and ECGF. Markedly diminished levels of mRNA encoding collagen type I were also observed in cultures incubated with ECGF alone. The results show that ECGF and heparin elicit a negative regulatory effect on collagen production, and that this inhibition is due largely to the down-regulation of the pro-alpha 1(I) of type I collagen gene. Furthermore, ECGF has a potent suppressive effect, and heparin provides an additive effect to this inhibitory phenomenon.

Histologic Characterization of Rat Vocal Fold Scarring

2005 ◽  
Vol 114 (3) ◽  
pp. 183-191 ◽  
Author(s):  
Tomoko Tateya ◽  
Jin Ho Sohn ◽  
Ichiro Tateya ◽  
Diane M. Bless
Keyword(s):  
Hyaluronic Acid ◽  
Vocal Fold ◽  
Type I Collagen ◽  
Collagen Type ◽  
Control Level ◽  
Vocal Folds ◽  
Collagen Type I ◽  
Type I ◽  
Type Iii ◽  
Blue Stain

This study aimed to clarify the characteristics of rat vocal fold scarring by examining the alteration of key components in the extracellular matrix: hyaluronic acid, collagen, and fibronectin. Under monitoring with a 1.9-mm-diameter telescope, unilateral vocal fold stripping was performed, and larynges were harvested at 2, 4, 8, and 12 weeks after operation. The vocal folds were histologically analyzed with Alcian blue stain, trichrome stain, and immunofluorescence of collagen type I, collagen type III, and fibronectin. The scarred vocal folds showed less hyaluronic acid and more collagen types I and III than did the controls at all time points. Type III was stable for 12 weeks, while type I declined until 8 weeks and thereafter remained unchanged. Fibronectin increased for 4 weeks and then decreased; it was close to the control level at 8 and 12 weeks. These results suggest that the tissue remodeling process in scarred vocal folds slows down around 2 months after wounding.

scholarly journals Maintenance of chondrocyte phenotype during expansion on PLLA microtopographies

2018 ◽  
Vol 9 ◽  
pp. 204173141878982 ◽  
Author(s):  
Elisa Costa ◽  
Cristina González-García ◽  
José Luis Gómez Ribelles ◽  
Manuel Salmerón-Sánchez
Keyword(s):  
Lactic Acid ◽  
Type I Collagen ◽  
Collagen Type ◽  
Articular Chondrocytes ◽  
Collagen Type I ◽  
Cell Phenotype ◽  
Type I ◽  
Type Ii ◽  
Collagen Type Ii ◽  
Chondrocyte Phenotype

Articular chondrocytes are difficult to grow, as they lose their characteristic phenotype following expansion on standard tissue culture plates. Here, we show that culturing them on surfaces of poly(L-lactic acid) of well-defined microtopography allows expansion and maintenance of characteristic chondrogenic markers. We investigated the dynamics of human chondrocyte dedifferentiation on the different poly(L-lactic acid) microtopographies by the expression of collagen type I, collagen type II and aggrecan at different culture times. When seeded on poly(L-lactic acid), chondrocytes maintained their characteristic hyaline phenotype up to 7 days, which allowed to expand the initial cell population approximately six times without cell dedifferentiation. Maintenance of cell phenotype was afterwards correlated to cell adhesion on the different substrates. Chondrocytes adhesion occurs via the α5 β1 integrin on poly(L-lactic acid), suggesting cell–fibronectin interactions. However, α2 β1 integrin is mainly expressed on the control substrate after 1 day of culture, and the characteristic chondrocytic markers are lost (collagen type II expression is overcome by the synthesis of collagen type I). Expanding chondrocytes on poly(L-lactic acid) might be an effective solution to prevent dedifferentiation and improving the number of cells needed for autologous chondrocyte transplantation.

A Newly Identified Platelet and Megakaryocyte Lysyl Oxidase-Adhesion to Collagen Axis in Human Primary Myelofibrosis

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3133-3133
Author(s):  
Alessandra Balduini ◽  
Vittorio Abbonante ◽  
Shinobu Matsuura ◽  
Vittorio Rosti ◽  
Katya Ravid
Keyword(s):  
Type I Collagen ◽  
Conflicts Of Interest ◽  
Lysyl Oxidase ◽  
Primary Myelofibrosis ◽  
Collagen Type I ◽  
Type I ◽  
Soluble Collagen ◽  
Peripheral Blood Cd34 ◽  
Acid Soluble Collagen

Abstract Controlling platelet function is central to management of various pathologies, including Primary Myelofibrosis (PMF), which is associated with increased incidence of thrombosis and cardiovascular disease. In recent studies we showed that the matrix cross-linking enzyme, Lysyl Oxidase (LOX) is elevated in platelets and megakartocytes of myelofibrotic mice, and transgenic upregulation of LOX increases platelet and megakaryocyte adhesion to monomeric type I collagen (preferred by alpha2β1 collagen receptors), and augments propensity for in vivo thrombosis. Here, we examined the relevance of these findings to human disease, by first determining platelet LOX level, as well as platelet and megakaryocyte adhesion to collagen using samples derived from PMF patients and matching controls. In analyzing 10 PMF platelet samples (5 males and 5 females; 6 JAK2V617F; 4 CALR mutations; age range 30-55; PMF grade 1-3), we found a nearly 20 fold upregulation of LOX expression compared to matching healthy controls (p<0.001). Intriguingly, there was a significant increase in adhesion (plt/mm2) and spreading (pixel2) of PMF platelets relative to control on monomeric, pepsinated acid soluble collagen (PSCI) (p<0.05), while no differences were observed between the samples on native triple helical acid soluble collagen type I collagen (ASCI). To examine the role of LOX in this phenotype, we treated control and PMF-derived human megakaryocytes, differentiated from peripheral blood CD34+ cells, grown in presence or not of LOX inhibitor, β-aminopropionitrile (BAPN) from day 2 of culture. Our preliminary data, based on a cohort of 2 controls and 5 PMF samples, demonstrated that although on ASCI megakaryocyte adhesion is not altered by BAPN treatment both in CTRL and PMF derived megakaryocytes, on PSCI the adhesion of PMF derived megakaryocytes was reduced by about a 50% by BAPN treatment, while the adhesion of CTRL derived MKs was not significantly affected. Taken together, we identified LOX level to be upregulated in human PMF platelets and megakaryocytes, and LOX activity to be important for PMF cells adhesion to collagen. These newly identified properties are highly relevant to megakaryocyte adhesion to the niche, and to platelet activation in PMF. Disclosures No relevant conflicts of interest to declare.

scholarly journals Experimental and Modeling Study of Collagen Scaffolds with the Effects of Crosslinking and Fiber Alignment

2011 ◽  
Vol 2011 ◽  
pp. 1-12 ◽  
Author(s):  
Bin Xu ◽  
Ming-Jay Chow ◽  
Yanhang Zhang
Keyword(s):  
Magnetic Particles ◽  
Type I Collagen ◽  
Collagen Gel ◽  
Collagen Type I ◽  
Mechanical Tests ◽  
Type I ◽  
Collagen Scaffolds ◽  
Fiber Alignment ◽  
Biaxial Tensile ◽  
Anisotropic Mechanical Properties

Collagen type I scaffolds are commonly used due to its abundance, biocompatibility, and ubiquity. Most applications require the scaffolds to operate under mechanical stresses. Therefore understanding and being able to control the structural-functional integrity of collagen scaffolds becomes crucial. Using a combined experimental and modeling approach, we studied the structure and function of Type I collagen gel with the effects of spatial fiber alignment and crosslinking. Aligned collagen scaffolds were created through the flow of magnetic particles enmeshed in collagen fibrils to mimic the anisotropy seen in native tissue. Inter- and intra- molecular crosslinking was modified chemically with Genipin to further improve the stiffness of collagen scaffolds. The anisotropic mechanical properties of collagen scaffolds were characterized using a planar biaxial tensile tester and parallel plate rheometer. The tangent stiffness from biaxial tensile test is two to three orders of magnitude higher than the storage moduli from rheological measurements. The biphasic nature of collagen gel was discussed and used to explain the mechanical behavior of collagen scaffolds under different types of mechanical tests. An anisotropic hyperelastic constitutive model was used to capture the characteristics of the stress-strain behavior exhibited by collagen scaffolds.

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