Influence of Decorin and Biglycan on Mechanical Properties of Multiple Tendons in Knockout Mice

2005 ◽  
Vol 127 (1) ◽  
pp. 181-185 ◽  
Author(s):  
Paul S. Robinson ◽  
Tung-Fu Huang ◽  
Elan Kazam ◽  
Renato V. Iozzo ◽  
David E. Birk ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Type I Collagen ◽  
Specific Treatment ◽  
Treatment Modalities ◽  
Type I ◽  
Tail Tendon ◽  
And Function ◽  
Flexor Digitorum ◽  
In Vivo Loading

Evaluations of tendon mechanical behavior based on biochemical and structural arrangement have implications for designing tendon specific treatment modalities or replacement strategies. In addition to the well studied type I collagen, other important constituents of tendon are the small proteoglycans (PGs). PGs have been shown to vary in concentration within differently loaded areas of tendon, implicating them in specific tendon function. This study measured the mechanical properties of multiple tendon tissues from normal mice and from mice with knock-outs of the PGs decorin or biglycan. Tail tendon fascicles, patellar tendons (PT), and flexor digitorum longus tendons (FDL), three tissues representing different in vivo loading environments, were characterized from the three groups of mice. It was hypothesized that the absence of decorin or biglycan would have individual effects on each type of tendon tissue. Surprisingly, no change in mechanical properties was observed for the tail tendon fascicles due to the PG knockouts. The loss of decorin affected the PT, causing an increase in modulus and stress relaxation, but had little effect on the FDL. Conversely, the loss of biglycan did not significantly affect the PT, but caused a reduction in both the maximum stress and modulus of the FDL. These results give mechanical support to previous biochemical data that tendons likely are uniquely tailored to their specific location and function. Variances such as those presented here need to be further characterized and taken into account when designing therapies or replacements for any one particular tendon.

scholarly journals Heterogeneity in proline hydroxylation of fibrillar collagens observed by mass spectrometry

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0250544
Author(s):  
Michele Kirchner ◽  
Haiteng Deng ◽  
Yujia Xu
Keyword(s):  
Mass Spectrometry ◽  
Type I Collagen ◽  
Major Protein ◽  
Type I ◽  
Post Translational Modification ◽  
Functional Roles ◽  
Collagen Triple Helix ◽  
Commercial Sources ◽  
Tail Tendon ◽  
And Function

Collagen is the major protein in the extracellular matrix and plays vital roles in tissue development and function. Collagen is also one of the most processed proteins in its biosynthesis. The most prominent post-translational modification (PTM) of collagen is the hydroxylation of Pro residues in the Y-position of the characteristic (Gly-Xaa-Yaa) repeating amino acid sequence of a collagen triple helix. Recent studies using mass spectrometry (MS) and tandem MS sequencing (MS/MS) have revealed unexpected hydroxylation of Pro residues in the X-positions (X-Hyp). The newly identified X-Hyp residues appear to be highly heterogeneous in location and percent occupancy. In order to understand the dynamic nature of the new X-Hyps and their potential impact on applications of MS and MS/MS for collagen research, we sampled four different collagen samples using standard MS and MS/MS techniques. We found considerable variations in the degree of PTMs of the same collagen from different organisms and/or tissues. The rat tail tendon type I collagen is particularly variable in terms of both over-hydroxylation of Pro in the X-position and under-hydroxylation of Pro in the Y-position. In contrast, only a few unexpected PTMs in collagens type I and type III from human placenta were observed. Some observations are not reproducible between different sequencing efforts of the same sample, presumably due to a low population and/or the unpredictable nature of the ionization process. Additionally, despite the heterogeneous preparation and sourcing, collagen samples from commercial sources do not show elevated variations in PTMs compared to samples prepared from a single tissue and/or organism. These findings will contribute to the growing body of information regarding the PTMs of collagen by MS technology, and culminate to a more comprehensive understanding of the extent and the functional roles of the PTMs of collagen.

scholarly journals The effect of collagen hydrogels on chondrocyte behaviors through restricting the contraction of cell/hydrogel constructs

2021 ◽  
Vol 8 (4) ◽  
Author(s):  
Longpeng Dong ◽  
Qingli Liu ◽  
Yongli Gao ◽  
Hengxing Jia ◽  
Wenling Dai ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Type I Collagen ◽  
Cell Counting ◽  
Type I ◽  
Dna Assays ◽  
Collagen Hydrogels ◽  
Degradation Properties ◽  
Histological Staining

Abstract Collagen is a promising material for tissue engineering, but the poor mechanical properties of collagen hydrogels, which tend to cause contraction under the action of cellular activity, make its application challengeable. In this study, the amino group of type I collagen (Col I) was modified with methacrylic anhydride (MA) and the photo-crosslinkable methacrylate anhydride modified type I collagen (CM) with three different degrees of substitution (DS) was prepared. The physical properties of CM and Col I hydrogels were tested, including micromorphology, mechanical properties and degradation properties. The results showed that the storage modulus and degradation rate of hydrogels could be adjusted by changing the DS of CM. In vitro, chondrocytes were seeded into these four groups of hydrogels and subjected to fluorescein diacetate/propidium iodide (FDA/PI) staining, cell counting kit-8 (CCK-8) test, histological staining and cartilage-related gene expression analysis. In vivo, these hydrogels encapsulating chondrocytes were implanted subcutaneously into nude mice, then histological staining and sulfated glycosaminoglycan (sGAG)/DNA assays were performed. The results demonstrated that contraction of hydrogels affected behaviors of chondrocytes, and CM hydrogels with suitable DS could resist contraction of hydrogels and promote the secretion of cartilage-specific matrix in vitro and in vivo.

scholarly journals Collagen overlays can inhibit leptin and adiponectin secretion but not lipid accumulation in adipocytes

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4641
Author(s):  
Sherri L. Christian ◽  
Nikitha K. Pallegar ◽  
Robert J. Brown ◽  
Alicia M. Viloria-Petit
Keyword(s):  
Type I Collagen ◽  
Whole Body ◽  
Type I ◽  
Function Type ◽  
Therapeutic Implications ◽  
Triglyceride Accumulation ◽  
Whole Body Metabolism ◽  
And Function

BackgroundWhite adipose tissue (WAT) is essential for energy storage as well as being an active endocrine organ. The secretion of adipokines by adipocytes can affect whole body metabolism, appetite, and contribute to overall health. WAT is comprised of lipid-laden mature adipocytes, as well as immune cells, endothelial cells, pre-adipocytes, and adipose-derived stem cells. In addition, the presence of extracellular matrix (ECM) proteins in WAT can actively influence adipocyte differentiation, growth, and function. Type I collagen is an abundant fibrous ECM protein in WAT that is secreted by developing adipocytes. However, the extent and overall effect of Type I collagen on adipokine secretion in mature adipocytes when added exogenously has not been established.MethodsWe characterized the effects of Type I collagen overlays prepared using two different buffers on adipocyte physiology and function when added at different times during differentiation. In addition, we compared the effect of collagen overlays when adipocytes were cultured on two different tissue culture plastics that have different adherent capabilities. Triglyceride accumulation was analyzed to measure adipocyte physiology, and leptin and adiponectin secretion was determined to analyze effects on adipokine secretion.ResultsWe found that collagen overlays, particularly when added during the early differentiation stage, impaired adipokine secretion from mature adipocytes. Collagen prepared using PBS had a greater suppression of leptin than adiponectin while collagen prepared using HANKS buffer suppressed the secretion of both adipokines. The use of CellBind plates further suppressed leptin secretion. Triglyceride accumulation was not substantially impacted with any of the collagen overlays.DiscussionAdipokine secretion can be selectively altered by collagen overlays. Thus, it is feasible to selectively manipulate the secretion of adipokines by adipocytesin vitroby altering the composition or timing of collagen overlays. The use of this technique could be applied to studies of adipokine function and secretionin vitroas well as having potential therapeutic implications to specifically alter adipocyte functionalityin vivo.

scholarly journals Adaptor protein CrkII negatively regulates osteoblast differentiation and function through JNK phosphorylation

2019 ◽  
Vol 51 (9) ◽  
pp. 1-10 ◽  
Author(s):  
Jung Ha Kim ◽  
Kabsun Kim ◽  
Inyoung Kim ◽  
Semun Seong ◽  
Kwang-Il Nam ◽  
...  
Keyword(s):  
Osteoblast Differentiation ◽  
Type I Collagen ◽  
Bone Cells ◽  
Biological Activities ◽  
Osteoclast Differentiation ◽  
Adaptor Protein ◽  
Type I ◽  
And Function

Abstract The adaptor protein CrkII is involved in several biological activities, including mitogenesis, phagocytosis, and cytoskeleton reorganization. Previously, we demonstrated that CrkII plays an important role in osteoclast differentiation and function through Rac1 activation both in vitro and in vivo. In this study, we investigated whether CrkII also regulates the differentiation and function of another type of bone cells, osteoblasts. Overexpression of CrkII in primary osteoblasts inhibited bone morphogenetic protein (BMP) 2-induced osteoblast differentiation and function, whereas knockdown of CrkII expression exerted the opposite effect. Importantly, CrkII strongly enhanced c-Jun-N-terminal kinase (JNK) phosphorylation, and the CrkII overexpression-mediated attenuation of osteoblast differentiation and function was recovered by JNK inhibitor treatment. Furthermore, transgenic mice overexpressing CrkII under control of the alpha-1 type I collagen promoter exhibited a reduced bone mass phenotype. Together, these results indicate that CrkII negatively regulates osteoblast differentiation and function through JNK phosphorylation. Given that CrkII acts as a negative and positive regulator of osteoblast and osteoclast differentiation, respectively, the regulation of CrkII expression in bone cells may help to develop new strategies to enhance bone formation and inhibit bone resorption.

scholarly journals Protective Effect of Ciclopirox against Ovariectomy-Induced Bone Loss in Mice by Suppressing Osteoclast Formation and Function

2021 ◽  
Vol 22 (15) ◽  
pp. 8299
Author(s):  
Hye Jung Ihn ◽  
Jiwon Lim ◽  
Kiryeong Kim ◽  
Sang-Hyeon Nam ◽  
Soomin Lim ◽  
...  
Keyword(s):  
Bone Loss ◽  
Type I Collagen ◽  
Osteoclast Differentiation ◽  
Osteoclast Formation ◽  
Bone Diseases ◽  
Mitogen Activated Protein Kinase ◽  
Type I ◽  
And Function

Postmenopausal osteoporosis is closely associated with excessive osteoclast formation and function, resulting in the loss of bone mass. Osteoclast-targeting agents have been developed to manage this disease. We examined the effects of ciclopirox on osteoclast differentiation and bone resorption in vitro and in vivo. Ciclopirox significantly inhibited osteoclast formation from primary murine bone marrow macrophages (BMMs) in response to receptor activator of nuclear factor kappa B ligand (RANKL), and the expression of genes associated with osteoclastogenesis and function was decreased. The formation of actin rings and resorption pits was suppressed by ciclopirox. Analysis of RANKL-mediated early signaling events in BMMs revealed that ciclopirox attenuates IκBα phosphorylation without affecting mitogen-activated protein kinase activation. Furthermore, the administration of ciclopirox suppressed osteoclast formation and bone loss in ovariectomy-induced osteoporosis in mice and reduced serum levels of osteocalcin and C-terminal telopeptide fragment of type I collagen C-terminus. These results indicate that ciclopirox exhibits antiosteoclastogenic activity both in vitro and in vivo and represents a new candidate compound for protection against osteoporosis and other osteoclast-related bone diseases.

scholarly journals Functional regeneration of tendons using scaffolds with physical anisotropy engineered via microarchitectural manipulation

2018 ◽  
Vol 4 (10) ◽  
pp. eaat4537 ◽  
Author(s):  
Z. Wang ◽  
W. J. Lee ◽  
B. T. H. Koh ◽  
M. Hong ◽  
W. Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Type I Collagen ◽  
Three Dimensional ◽  
Type I ◽  
High Porosity ◽  
Cytoskeletal Network ◽  
Function Relationship ◽  
Living Tissues

Structural and hierarchical anisotropy underlies the structure-function relationship of most living tissues. Attempts to exploit the interplay between cells and their immediate environment have rarely featured macroscale, three-dimensional constructs required for clinical applications. Furthermore, compromises to biomechanical robustness during fabrication often limit the scaffold’s relevance in translational medicine. We report a polymeric three-dimensional scaffold with tendon-like mechanical properties and controlled anisotropic microstructures. The scaffold was composed of two distinct portions, which enabled high porosity while retaining tendon-like mechanical properties. When tenocytes were cultured in vitro on the scaffold, phenotypic markers of tenogenesis such as type-I collagen, decorin, and tenascin were significantly expressed over nonanisotropic controls. Moreover, highly aligned intracellular cytoskeletal network and high nuclear alignment efficiencies were observed, suggesting that microstructural anisotropy might play the epigenetic role of mechanotransduction. When implanted in an in vivo micropig model, a neotissue that formed over the scaffold resembled native tendon tissue in composition and structure.

scholarly journals Collagen overlays can inhibit leptin and adiponectin secretion but not lipid accumulation in adipocytes

2018 ◽  
Author(s):  
Sherri Lynn Christian ◽  
Nikitha K Pallegar ◽  
Robert J Brown ◽  
Alicia M Viloria-Petit
Keyword(s):  
Type I Collagen ◽  
Whole Body ◽  
Type I ◽  
Function Type ◽  
Therapeutic Implications ◽  
Triglyceride Accumulation ◽  
Whole Body Metabolism ◽  
And Function

Background. White adipose tissue (WAT) is essential for energy storage as well as being an active endocrine organ. The secretion of adipokines by adipocytes can affect whole body metabolism, appetite, and contribute to overall health. WAT is comprised of lipid-laden mature adipocytes, as well as immune cells, endothelial cells, pre-adipocytes, and adipose-derived stem cells. In addition, the presence of extracellular matrix (ECM) proteins in WAT can actively influence adipocyte differentiation, growth, and function. Type I collagen is an abundant fibrous ECM protein in WAT that is secreted by developing adipocytes. However, the extent and overall effect of Type I collagen on adipokine secretion in mature adipocytes when added exogenously has not been established. Methods. We characterized the effects of Type I collagen overlays prepared using two different buffers on adipocyte physiology and function when added at different times during differentiation. In addition, we compared the effect of collagen overlays when adipocytes were cultured on two different tissue culture plastics that have different adherent capabilities. Triglyceride accumulation was analyzed to measure adipocyte physiology, and leptin and adiponectin secretion was determined to analyze effects on adipokine secretion. Results. We found that collagen overlays, particularly when added during the early differentiation stage, impaired adipokine secretion from mature adipocytes. Collagen prepared using PBS had a greater suppression of leptin than adiponectin while collagen prepared using HANKS buffer suppressed the secretion of both adipokines. The use of CellBind plates further suppressed leptin secretion. Triglyceride accumulation was minimally impacted with any of the collagen overlays. Discussion. Adipokine secretion can be selectively altered by collagen overlays. Thus, it is feasible to selectively manipulate the secretion of adipokines by adipocytes in vitro by altering the composition or timing of collagen overlays. The use of this technique could be applied to studies of adipokine function and secretion in vitro as well as having potential therapeutic implications to specifically alter adipocyte functionality in vivo.

scholarly journals Collagen overlays can inhibit leptin and adiponectin secretion but not lipid accumulation in adipocytes

2018 ◽  
Author(s):  
Sherri Lynn Christian ◽  
Nikitha K Pallegar ◽  
Robert J Brown ◽  
Alicia M Viloria-Petit
Keyword(s):  
Type I Collagen ◽  
Whole Body ◽  
Type I ◽  
Function Type ◽  
Therapeutic Implications ◽  
Triglyceride Accumulation ◽  
Whole Body Metabolism ◽  
And Function

Background. White adipose tissue (WAT) is essential for energy storage as well as being an active endocrine organ. The secretion of adipokines by adipocytes can affect whole body metabolism, appetite, and contribute to overall health. WAT is comprised of lipid-laden mature adipocytes, as well as immune cells, endothelial cells, pre-adipocytes, and adipose-derived stem cells. In addition, the presence of extracellular matrix (ECM) proteins in WAT can actively influence adipocyte differentiation, growth, and function. Type I collagen is an abundant fibrous ECM protein in WAT that is secreted by developing adipocytes. However, the extent and overall effect of Type I collagen on adipokine secretion in mature adipocytes when added exogenously has not been established. Methods. We characterized the effects of Type I collagen overlays prepared using two different buffers on adipocyte physiology and function when added at different times during differentiation. In addition, we compared the effect of collagen overlays when adipocytes were cultured on two different tissue culture plastics that have different adherent capabilities. Triglyceride accumulation was analyzed to measure adipocyte physiology, and leptin and adiponectin secretion was determined to analyze effects on adipokine secretion. Results. We found that collagen overlays, particularly when added during the early differentiation stage, impaired adipokine secretion from mature adipocytes. Collagen prepared using PBS had a greater suppression of leptin than adiponectin while collagen prepared using HANKS buffer suppressed the secretion of both adipokines. The use of CellBind plates further suppressed leptin secretion. Triglyceride accumulation was minimally impacted with any of the collagen overlays. Discussion. Adipokine secretion can be selectively altered by collagen overlays. Thus, it is feasible to selectively manipulate the secretion of adipokines by adipocytes in vitro by altering the composition or timing of collagen overlays. The use of this technique could be applied to studies of adipokine function and secretion in vitro as well as having potential therapeutic implications to specifically alter adipocyte functionality in vivo.

Collagen-the Ultrastructural Element of the Bone Matrix

2018 ◽  
Vol 69 (7) ◽  
pp. 1706-1709
Author(s):  
Nicoleta Dumitru ◽  
Andra Cocolos ◽  
Andra Caragheorgheopol ◽  
Constantin Dumitrache ◽  
Ovidiu Gabriel Bratu ◽  
...  
Keyword(s):  
Type I Collagen ◽  
Bone Microarchitecture ◽  
Complex Structure ◽  
Bone Matrix ◽  
Organic Matrix ◽  
Bone Diseases ◽  
Bone Collagen ◽  
Type I ◽  
New Therapeutic Approaches ◽  
And Function

There is an increased interest and more studies highlight the fact that bone strength depends not only on bone tissue quantity, but also on its quality, which is characterized by the geometry and shape of bones, trabecular bone microarchitecture, mineral content, organic matrix and bone turnover. Fibrillar type I collagen is the major organic component of bone matrix, providing form and a stable template for mineralization. The biomedical importance of collagen as a biomaterial for medical and cosmetic purposes and the improvement of the molecular, cellular biology and analytical technologies, led to increasing interest in establishing the structure of this protein and in setting of the relationships between sequence, structure, and function. Bone collagen crosslinking chemistry and its molecular packing structure are considered to be distinct features. This unique post-translational modifications provide to the fibrillar collagen matrices properties such as tensile strength and viscoelasticity. Understanding the complex structure of bone type I collagen as well as the dynamic nature of bone tissues will help to manage new therapeutic approaches to bone diseases.

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