scholarly journals A Reconsideration of the Effect of Procyanidin on the Assembly of Collagen Type I

2018 ◽  
Author(s):  
Y. Wang ◽  
L. Jin
Keyword(s):  
Collagen Type I ◽  
Type I ◽  
Cd Spectra ◽  
Effect Mechanism ◽  
Atomic Force ◽  
Before And After ◽  
Collagen Molecules ◽  
Exact Effect ◽  
Positive Effect ◽  
Thermal Stability Of

ABSTRACTIn order to elucidating the exact effect mechanism of polyphenols on the assembly of collagen, the assembled architectures of collagen treated with different amounts of procyanidin (PA) were investigated in details. The assembled morphologies of collagen were greatly influenced by the content of PA according to atomic force microcopy (AFM) images. When the content of PA was more than 20% (w/w), the fibrillar morphologies were substituted by globular aggregates, which were driven by the intense hydrogen bonding action originating from PA. While the formation of the non-fibrous aggregates was due to the coiling and entangling of flexible collagen molecules rather than their gelatinization based on the appearance of typical adsorption peaks at 222nm and 197nm on circular dichroism (CD) spectra. After being crosslinked by glutaraldehyde (GA), not only the diameters but also the lengths of fibrils increased. Unfortunately, the fibrillogenesis was still inhibited when the collagen suffered from 20% PA firstly and then 4% GA. Conversely, the fibrous morphologies of the fibrils stabilized by 4% GA and then underwent 20% PA maintained well, in spite of accompanying with grievous intertwining. This difference was derived from the change of flexibilities of collagen before and after being crosslinked by GA. Additionally, the differential scanning calorimeter (DSC) analysis confirmed the PA had no positive effect on the improvement of thermal stability of hydrous collagen, whereas the denaturation temperature of hydrated collagen stabilized by 4% GA increased from 40 °C to 80 °C.

Study of Nano-Mechanics of Collagen I Triple-helices by Computerized Processing of AFM Images

2012 ◽  
Vol 1422 ◽  
Author(s):  
Arkady Bitler ◽  
Emanuel Perugia ◽  
Sidney R. Cohen
Keyword(s):  
Mechanical Properties ◽  
Persistence Length ◽  
Collagen Type I ◽  
Segment Length ◽  
Type I ◽  
Ambient Conditions ◽  
Atomic Force ◽  
Collagen Molecules ◽  
High Resolution Images ◽  
Triple Helices

ABSTRACTWe used atomic force microscope (AFM) to acquire high-resolution images of collagen type I triple-helices under ambient conditions in tapping mode. Angles between consecutive fixed-length segments were measured and analyzed to yield persistence length and elastic constant. Changing the segment length allowed exploring the mechanics at various scales. Understanding the mechanical properties of collagen molecules could serve to elucidate mechanisms of complex mechanical properties of interest in nanomedicine and nanotechnology.

Acute and specific collagen type I degradation increases diastolic and developed tension in perfused rat papillary muscle

2004 ◽  
Vol 286 (3) ◽  
pp. H889-H894 ◽  
Author(s):  
Regis R. Lamberts ◽  
Maurice J. J. M. F. Willemsen ◽  
Néstor G. Pérez ◽  
Pieter Sipkema ◽  
Nico Westerhof
Keyword(s):  
Papillary Muscle ◽  
Collagen Type ◽  
Perfusion Pressure ◽  
Collagen Type I ◽  
Type I ◽  
Collagenase Treatment ◽  
Before And After ◽  
Diastolic Coronary Flow ◽  
Rat Papillary Muscle

Collagen degradation is suggested to be responsible for long-term contractile dysfunction in different cardiomyopathies, but the effects of acute and specific collagen type I removal (main type in the heart muscle) on tension have not been studied. We determined the diastolic and developed tension length relations in isometric contracting perfused rat papillary muscles (perfusion pressure 60 cmH2O) before and after acute and specific removal of small collagen struts with the use of purified collagenase type I. At 95% of the maximal length (95% Lmax), diastolic tension increased 20.4 ± 8.1% ( P < 0.05, n = 6) and developed tension increased 15.0 ± 6.7% after collagenase treatment compared with time controls. Treatment increased the diastolic muscle diameter by 7.1 ± 3.4% at 95% Lmax, whereas the change in diameter due to contraction was not changed. Diastolic coronary flow and normalized coronary arterial flow impediment did not change after collagenase treatment. Electron microscopy revealed that the number of small collagen struts, interconnecting myocytes, and capillaries was reduced to ∼32% after treatment. We conclude that removal of the small collagen struts by acute and specific collagen type I degradation increases diastolic and developed tension in perfused papillary muscle. We suggest that diastolic tension is increased due to edema, whereas developed tension is increased because the removal of the struts poses a lower lateral load on the cardiac myocytes, allowing more myocyte thickening.

Enhancement by Heparin of Affinity between Cold-Insoluble Globulin and Native Collagen Type III

1979 ◽  
Author(s):  
H. Hörmann ◽  
F. Jilek
Keyword(s):  
Collagen Type ◽  
Weight Ratio ◽  
Collagen Type I ◽  
Type I ◽  
Collagen Type Iii ◽  
Type Iii ◽  
Soluble Collagen ◽  
Native Collagen ◽  
Collagen Molecules ◽  
Cold Insoluble Globulin

Affinity between collagen and cold-insoluble globulin was measured by complexing soluble 125-J labelled collagen preparations with the globulin. Precipitates containing considerable activity were formed at 4°C and 22°C by denatured soluble collagen, type I and type III, but only little by native soluble collagen. The precipitation of native collagen, type III, by cold-insoluble globulin was enhanced by heparin. Under optimal conditions at a weight ratio or heparin and cold-insoluble globulin of about 1:1 up to 60% of the collagen applied was insolubilized. Native collagen, type I, was complexed far less effectively even in presence of heparin. Electronmicroscopic and precipitation experiments using 125-J labelled cold-insoluble globulin indicated that heparin might induce a partial conversion of cold-insoluble globulin to a fibrillar derivative which exhibited improved binding properties for the rod-like native collagen molecules. – Supported by Deutsche Forschungsgemeinschaft, Project Ho 740/1.

scholarly journals Increased Bone Resorption during Lactation in Pycnodysostosis

2021 ◽  
Vol 22 (4) ◽  
pp. 1810
Author(s):  
Ineke D.C. Jansen ◽  
Socrates E. Papapoulos ◽  
Nathalie Bravenboer ◽  
Teun J. de Vries ◽  
Natasha M. Appelman-Dijkstra
Keyword(s):  
Bone Resorption ◽  
Cathepsin K ◽  
Collagen Type I ◽  
Type I ◽  
Lactation Period ◽  
Blood Monocytes ◽  
Lactating Women ◽  
Before And After ◽  
K Deficiency

Pycnodysostosis, a rare autosomal recessive skeletal dysplasia, is caused by a deficiency of cathepsin K. Patients have impaired bone resorption in the presence of normal or increased numbers of multinucleated, but dysfunctional, osteoclasts. Cathepsin K degrades collagen type I and generates N-telopeptide (NTX) and the C-telopeptide (CTX) that can be quantified. Levels of these telopeptides are increased in lactating women and are associated with increased bone resorption. Nothing is known about the consequences of cathepsin K deficiency in lactating women. Here we present for the first time normalized blood and CTX measurements in a patient with pycnodysostosis, exclusively related to the lactation period. In vitro studies using osteoclasts derived from blood monocytes during lactation and after weaning further show consistent bone resorption before and after lactation. Increased expression of cathepsins L and S in osteoclasts derived from the lactating patient suggests that other proteinases could compensate for the lack of cathepsin K during the lactation period of pycnodysostosis patients.

scholarly journals Atomic Force Microscopy for Collagen-Based Nanobiomaterials

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Andreas Stylianou
Keyword(s):  
Thin Films ◽  
Atomic Force Microscopy ◽  
Collagen Type I ◽  
Quantitative Information ◽  
Fibrillar Structure ◽  
Type I ◽  
Force Microscopy ◽  
Atomic Force ◽  
Wide Range

Novel nanobiomaterials are increasingly gaining ground in bioengineering research. Among the numerous biomaterials, collagen-nanobiomaterials, such as collagen thin films, are of great interest since they present a wide range of applications in the fields of biomaterials, tissue engineering, and biomedicine. Collagen type I is the most abundant protein within extracellular matrix and, due to its unique characteristics, is widely used as biomaterial. A thorough characterization of the structure and properties of nanomaterials can be achieved by Atomic Force Microscopy (AFM). AFM is a very powerful tool which can be used to obtain qualitative or quantitative information without destroying the collagen fibrillar structure. This mini review covers issues related to the use of AFM for studying the structure and mechanical properties of collagen-based nanobiomaterials, collagen-substrate interactions during the formation of collagen thin films, collagen-cells interactions, and the collagen-optical radiation interactions.

scholarly journals Soluble Interleukin-6 Receptor Regulates Interleukin-6-Dependent Vascular Remodeling in Long-Distance Runners

2021 ◽  
Vol 12 ◽  
Author(s):  
Paulina Villar-Fincheira ◽  
Aaron J. Paredes ◽  
Tomás Hernández-Díaz ◽  
Ignacio Norambuena-Soto ◽  
Nicole Cancino-Arenas ◽  
...  
Keyword(s):  
Interleukin 6 ◽  
Vascular Remodeling ◽  
Collagen Type I ◽  
Inhibitory Effect ◽  
Ascending Aorta ◽  
Training Load ◽  
Type I ◽  
Long Distance ◽  
Before And After

Little is known about the effects of training load on exercise-induced plasma increase of interleukin-6 (IL-6) and soluble IL-6 receptor (sIL-6R) and their relationship with vascular remodeling. We sought to evaluate the role of sIL 6R as a regulator of IL-6-induced vascular remodeling. Forty-four male marathon runners were recruited and allocated into two groups: low-training (LT, &lt;100 km/week) and high-training (HT, ≥100 km/week), 22 athletes per group. Twenty-one sedentary participants were used as reference. IL-6, sIL-6R and sgp130 levels were measured in plasma samples obtained before and immediately after finishing a marathon (42.2-km). Aortic diameter was measured by echocardiography. The inhibitory effect of sIL-6R on IL-6-induced VSMC migration was assessed using cultured A7r5 VSMCs. Basal plasma IL-6 and sIL-6R levels were similar among sedentary and athlete groups. Plasma IL-6 and sIL-6R levels were elevated after the marathon, and HT athletes had higher post-race plasma sIL-6R, but not IL-6, level than LT athletes. No changes in sgp130 plasma levels were found in LT and HT groups before and after running the marathon. Athletes had a more dilated ascending aorta and aortic root than sedentary participants with no differences between HT and LT athletes. However, a positive correlation between ascending aorta diameter and plasma IL-6 levels corrected by training load and years of training was observed. IL-6 could be responsible for aorta dilation because IL-6 stimulated VSMC migration in vitro, an effect that is inhibited by sIL-6R. However, IL-6 did not modify cell proliferation, collagen type I and contractile protein of VSMC. Our results suggest that exercise induces vascular remodeling. A possible association with IL-6 is proposed. Because sIL-6R inhibits IL-6-induced VSMC migration, a possible mechanism to regulate IL-6-dependent VSMC migration is also proposed.

scholarly journals Biomimetic Surfaces Coated with Covalently Immobilized Collagen Type I: An X-Ray Photoelectron Spectroscopy, Atomic Force Microscopy, Micro-CT and Histomorphometrical Study in Rabbits

2019 ◽  
Vol 20 (3) ◽  
pp. 724 ◽  
Author(s):  
Antonio Scarano ◽  
Felice Lorusso ◽  
Tiziana Orsini ◽  
Marco Morra ◽  
Giorgio Iviglia ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Photoelectron Spectroscopy ◽  
Collagen Type ◽  
Collagen Type I ◽  
Type I ◽  
Micro Ct ◽  
Implant Surface ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force

Background: The process of osseointegration of dental implants is characterized by healing phenomena at the level of the interface between the surface and the bone. Implant surface modification has been introduced in order to increase the level of osseointegration. The purpose of this study is to evaluate the influence of biofunctional coatings for dental implants and the bone healing response in a rabbit model. The implant surface coated with collagen type I was analyzed through X-ray Photoelectron Spectroscopy (XPS), Atomic Force Microscopy (AFM), micro-CT and histologically. Methods: The sandblasted and double acid etched surface coated with collagen type I, and uncoated sandblasted and double acid etched surface were evaluated by X-ray Photoelectron Spectroscopy (XPS) and Atomic Force Microscopy (AFM) analysis in order evaluate the different morphology. In vivo, a total of 36 implants were positioned in rabbit articular femoral knee-joint, 18 fixtures for each surface. Micro-CT scans, histological and histomorphometrical analysis were conducted at 15, 30 and 60 days. Results: A histological statistical differences were evident at 15, 30 and 60 days (p < 0.001). Both implant surfaces showed a close interaction with newly formed bone. Mature bone appeared in close contact with the surface of the fixture. The AFM outcome showed a similar roughness for both surfaces. Conclusion: However, the final results showed that a coating of collagen type I on the implant surface represents a promising procedure able to improve osseointegration, especially in regions with a low bone quality.

scholarly journals Mechanisms of Normalisation of Bone Metabolism during Recovery from Hyperthyroidism: Potential Role for Sclerostin and Parathyroid Hormone

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Elżbieta Skowrońska-Jóźwiak ◽  
Krzysztof C. Lewandowski ◽  
Zbigniew Adamczewski ◽  
Kinga Krawczyk-Rusiecka ◽  
Andrzej Lewiński
Keyword(s):  
Parathyroid Hormone ◽  
Bone Metabolism ◽  
Potential Role ◽  
Bone Markers ◽  
Collagen Type ◽  
Collagen Type I ◽  
Negative Regulator ◽  
Type I ◽  
Before And After ◽  
The Relationship

Sclerostin, a protein expressed by osteocytes, is a negative regulator of bone formation. The aim of the study was to investigate the relationship between parathyroid hormone (PTH) and markers of bone metabolism and changes of sclerostin concentrations before and after treatment of hyperthyroidism.Patients and Methods. The study involved 33 patients (26 women), age (mean ± SD) 48 ± 15 years, with hyperthyroidism. Serum sclerostin, PTH, calcium, and bone markers [osteocalcin (OC) and collagen type I cross-linked C-telopeptide I (CTX)] were measured at diagnosis of hyperthyroidism and after treatment with thiamazole.Results. After treatment of hyperthyroidism a significant decrease in free T3(FT3) and free T4(FT4) concentrations was accompanied by marked decrease of serum sclerostin (from 43.7 ± 29.3 to 28.1 ± 18.4 pmol/L;p<0.001), OC (from 35.6 ± 22.0 to 27.0 ± 14.3 ng/mL;p<0.001), and CTX (from 0.49 ± 0.35 to 0.35 ± 0.23 ng/dL;p<0.005), accompanied by an increase of PTH (from 29.3 ± 14.9 to 39.8 ± 19.8;p<0.001). During hyperthyroidism there was a positive correlation between sclerostin and CTX (rs=0.41,p<0.05) and between OC and thyroid hormones (with FT3  rs=0.42, with FT4  rs=0.45,p<0.05).Conclusions. Successful treatment of hyperthyroidism results in a significant decrease in serum sclerostin and bone markers concentrations, accompanied by an increase of PTH.

Effect of Inorganic Ions on Morphology and Crystallinity of Collagen Fibrils

2007 ◽  
Vol 342-343 ◽  
pp. 929-932
Author(s):  
Qing Rong Wei ◽  
Xiu Dong Yang ◽  
Jian Lu ◽  
Bo Zhang ◽  
Bo Jiang ◽  
...  
Keyword(s):  
Self Assembly ◽  
Inorganic Ions ◽  
Collagen Type I ◽  
Collagen Fibrils ◽  
Type I ◽  
X Ray Diffraction ◽  
Collagen Molecules ◽  
Natural Biomaterial ◽  
Preliminary Study ◽  
Initial Results

As a natural biomaterial, collagen especially pepsin-solubilized collagen (type I) has been used widely in biomedical fields due to its excellent biocompatibility. In this preliminary study, we investigate the effect of some inorganic ions which are frequently utilized in the preparation of collagen on the morphology and crystallinity of fibrils. The scanning electron microscope and x-ray diffraction were applied to analyze the morphology and the crystallization of the reconstituted collagen fibrils, respectively. Although further studies are needed, these initial results indicate that by controlling the self-assembly conditions of collagen molecules, we may achieve the desired properties of fibrillar collagen products.

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