Ectopic osteogenesis by type I collagen loaded with a novel synthesized PTH‐related peptide‐1 in vivo

2019 ◽  
Vol 108 (1) ◽  
pp. 166-177 ◽  
Author(s):  
Yi Wang ◽  
Jianping Wang ◽  
Jin Zheng ◽  
Mingxia Yu ◽  
Lin Cai ◽  
...  
Keyword(s):  
Type I Collagen ◽  
Type I ◽  
Related Peptide ◽  
Ectopic Osteogenesis

scholarly journals Effects of chitosan-collagen dressing on wound healing in vitro and in vivo assays

2021 ◽  
Vol 19 ◽  
pp. 228080002198969
Author(s):  
Min-Xia Zhang ◽  
Wan-Yi Zhao ◽  
Qing-Qing Fang ◽  
Xiao-Feng Wang ◽  
Chun-Ye Chen ◽  
...  
Keyword(s):  
Wound Healing ◽  
Wound Dressing ◽  
Type I Collagen ◽  
Inhibition Zone ◽  
Negative Control ◽  
Type I ◽  
Nih3t3 Cells ◽  
Post Operation

The present study was designed to fabricate a new chitosan-collagen sponge (CCS) for potential wound dressing applications. CCS was fabricated by a 3.0% chitosan mixture with a 1.0% type I collagen (7:3(w/w)) through freeze-drying. Then the dressing was prepared to evaluate its properties through a series of tests. The new-made dressing demonstrated its safety toward NIH3T3 cells. Furthermore, the CCS showed the significant surround inhibition zone than empty controls inoculated by E. coli and S. aureus. Moreover, the moisture rates of CCS were increased more rapidly than the collagen and blank sponge groups. The results revealed that the CCS had the characteristics of nontoxicity, biocompatibility, good antibacterial activity, and water retention. We used a full-thickness excisional wound healing model to evaluate the in vivo efficacy of the new dressing. The results showed remarkable healing at 14th day post-operation compared with injuries treated with collagen only as a negative control in addition to chitosan only. Our results suggest that the chitosan-collagen wound dressing were identified as a new promising candidate for further wound application.

Vitamin K promotes mineralization, osteoblast-to-osteocyte transition, and an anticatabolic phenotype by γ-carboxylation-dependent and -independent mechanisms

2009 ◽  
Vol 297 (6) ◽  
pp. C1358-C1367 ◽  
Author(s):  
Gerald J. Atkins ◽  
Katie J. Welldon ◽  
Asiri R. Wijenayaka ◽  
Lynda F. Bonewald ◽  
David M. Findlay
Keyword(s):  
Bone Formation ◽  
Vitamin K ◽  
Type I Collagen ◽  
Vitamin K2 ◽  
Type I ◽  
Vitamin K1 ◽  
Vitamin K3 ◽  
Positive Effect

The vitamin K family members phylloquinone (vitamin K1) and the menaquinones (vitamin K2) are under study for their roles in bone metabolism and as potential therapeutic agents for skeletal diseases. We have investigated the effects of two naturally occurring homologs, phytonadione (vitamin K1) and menatetrenone (vitamin K2), and those of the synthetic vitamin K, menadione (vitamin K3), on human primary osteoblasts. All homologs promoted in vitro mineralization by these cells. Vitamin K1-induced mineralization was highly sensitive to warfarin, whereas that induced by vitamins K2 and K3 was less sensitive, implying that γ-carboxylation and other mechanisms, possibly genomic actions through activation of the steroid xenobiotic receptor, are involved in the effect. The positive effect on mineralization was associated with decreased matrix synthesis, evidenced by a decrease from control in expression of type I collagen mRNA, implying a maturational effect. Incubation in the presence of vitamin K2 or K3 in a three-dimensional type I collagen gel culture system resulted in increased numbers of cells with elongated cytoplasmic processes resembling osteocytes. This effect was not warfarin sensitive. Addition of calcein to vitamin K-treated cells revealed vitamin K-dependent deposition of mineral associated with cell processes. These effects are consistent with vitamin K promoting the osteoblast-to-osteocyte transition in humans. To test whether vitamin K may also act on mature osteocytes, we tested the effects of vitamin K on MLO-Y4 cells. Vitamin K reduced receptor activator of NF-κB ligand expression relative to osteoprotegerin by MLO-Y4 cells, an effect also seen in human cultures. Together, our findings suggest that vitamin K promotes the osteoblast-to-osteocyte transition, at the same time decreasing the osteoclastogenic potential of these cells. These may be mechanisms by which vitamin K optimizes bone formation and integrity in vivo and may help explain the net positive effect of vitamin K on bone formation.

Cells in regenerating deer antler cartilage provide a microenvironment that supports osteoclast differentiation

2001 ◽  
Vol 204 (3) ◽  
pp. 443-455
Author(s):  
C. Faucheux ◽  
S. Nesbitt ◽  
M. Horton ◽  
J. Price
Keyword(s):  
Type I Collagen ◽  
Mononuclear Cells ◽  
Osteoclast Differentiation ◽  
Cathepsin K ◽  
Collagen Matrix ◽  
Tartrate Resistant Acid Phosphatase ◽  
Type I ◽  
Deer Antler

Deer antlers are a rare example of mammalian epimorphic regeneration. Each year, the antlers re-grow by a modified endochondral ossification process that involves extensive remodelling of cartilage by osteoclasts. This study identified regenerating antler cartilage as a site of osteoclastogenesis in vivo. An in vitro model was then developed to study antler osteoclast differentiation. Cultured as a high-density micromass, cells from non-mineralised cartilage supported the differentiation of large numbers of osteoclast-like multinucleated cells (MNCs) in the absence of factors normally required for osteoclastogenesis. After 48 h of culture, tartrate-resistant acid phosphatase (TRAP)-positive mononuclear cells (osteoclast precursors) were visible, and by day 14 a large number of TRAP-positive MNCs had formed (783+/−200 per well, mean +/− s.e.m., N=4). Reverse transcriptase/polymerase chain reaction (RT-PCR) showed that receptor activator of NF κ B ligand (RANKL) and macrophage colony stimulating factor (M-CSF) mRNAs were expressed in micromass cultures. Antler MNCs have the phenotype of osteoclasts from mammalian bone; they expressed TRAP, vitronectin and calcitonin receptors and, when cultured on dentine, formed F-actin rings and large resorption pits. When cultured on glass, antler MNCs appeared to digest the matrix of the micromass and endocytose type I collagen. Matrix metalloproteinase-9 (MMP-9) may play a role in the resorption of this non-mineralised matrix since it is highly expressed in 100 % of MNCs. In contrast, cathepsin K, another enzyme expressed in osteoclasts from bone, is only highly expressed in resorbing MNCs cultured on dentine. This study identifies the deer antler as a valuable model that can be used to study the differentiation and function of osteoclasts in adult regenerating mineralised tissues.

Tissue specificity of type I collagen gene expression is determined at both transcriptional and post-transcriptional levels

1984 ◽  
Vol 4 (9) ◽  
pp. 1843-1852
Author(s):  
R J Focht ◽  
S L Adams
Keyword(s):  
Gene Expression ◽  
Rna Structure ◽  
Type I Collagen ◽  
Translational Efficiency ◽  
Type I ◽  
Collagen Gene ◽  
Differentiated Cells ◽  
Collagen Gene Expression

We analyzed the control of type I collagen synthesis in four kinds of differentiated cells from chicken embryos which synthesize very different amounts of the protein. Tendon, skin, and smooth muscle cells were found to have identical amounts of type I collagen RNAs; however, the RNAs had inherently different translatabilities, which were observed both in vivo and in vitro. Chondrocytes also had substantial amounts of type I collagen RNAs, even though they directed no detectable synthesis of the protein either in vivo or in vitro. Type I collagen RNAs in chondrocytes display altered electrophoretic mobilities, suggesting that in these cells the reduction in translational efficiency may be mediated in part by changes in the RNA structure. These data indicate that control of type I collagen gene expression is a complex process which is exerted at both transcriptional and post-transcriptional levels.

The influence of the haematocrit on primary haemostasis in vitro

2005 ◽  
Vol 94 (12) ◽  
pp. 1213-1218 ◽  
Author(s):  
Marco Eugster ◽  
Walter H. Reinhart
Keyword(s):  
Platelet Function ◽  
Type I Collagen ◽  
Inverse Correlation ◽  
Type I ◽  
Membrane Pore ◽  
Closure Time ◽  
Function Analyzer ◽  
Platelet Function Analyzer

SummaryPrimary haemostasis consists of platelet adhesion to subendothelial collagen, their activation and aggregation and finally the formation of a platelet plug. Erythrocytes are involved in this process because they flow in the center of the vessel and push platelets towards the site of action on the vessel wall and enhance shear forces, which activate platelets. In the platelet function analyzer PFA-100® (Dade Behring, Düdingen, Switzerland), the in vivo situation is simulated in vitro with blood being aspirated at high shear rates (5000s-1) through a capillary into a membrane pore with a diameter of 150 μm coated with type I collagen and either epinephrine or adenosine diphosphate. Aggregating platelets plug the pore and stop the flow, which is measured as the closure time. We analysed the influence of erythrocytes on platelet function analyzer measurements by systematic variation of the haematocrit (20,30,40,and 50%) at constant platelet counts of 289±61 ×103/μl plasma, or 152±30 ×103/μl blood, 96±9 ×103/μl blood and 54±5 ×103/μl blood, respectively. An inverse correlation was found between haematocrit and closure time under all circumstances. A decrease of the platelet count by 50 ×103 /μl could be compensated for by a 10% increase in haematocrit. The haematocrit must, therefore, be taken into consideration for the correct interpretation of PFA-100® measurements. Our data also provide a pathophysiological rationale to reduce the risk of bleeding in patients with thrombocytopenia and anaemia by normalizing the haematocrit with erythrocyte transfusions.

APPLICATION OF DENDRIMER/PLASMID hBMP-2 COMPLEXES LOADED INTO β-TCP/COLLAGEN SCAFFOLD IN THE TREATMENT OF FEMORAL DEFECTS IN RATS

2014 ◽  
Vol 26 (01) ◽  
pp. 1450005 ◽  
Author(s):  
Tingwei Bao ◽  
Huiming Wang ◽  
Wentao Zhang ◽  
Xuefeng Xia ◽  
Jiabei Zhou ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Type I Collagen ◽  
Cell Attachment ◽  
Collagen Scaffold ◽  
Bone Defects ◽  
Bone Morphogenetic Protein 2 ◽  
Porous Scaffolds ◽  
Type I

Purpose: Plasmid loading into scaffolds to enhance sustained release of growth factors is an important focus of regenerative medicine. The aim of this study was to build gene-activated matrices (GAMs) and examine the bone augmentation properties. Methods: Generation 5 polyamidoamine dendrimers (G5 dPAMAM)/plasmid recombinant human bone morphogenetic protein-2 (rhBMP-2) complexes were immobilized into beta-tricalcium phosphate (β-TCP)/type I collagen porous scaffolds. After cultured with rat mesenchymal stem cells (rMSCs), transfection efficiencies were examined. The secretion of rhBMP-2 and alkaline phosphatase (ALP) were detected to evaluate the osteogenic properties. Scanning electron microscopy (SEM) was used to observe attachment and proliferation. Moreover, we applied these GAMs directly into freshly created segmental bone defects in rat femurs, and their osteogenic efficiencies were evaluated. Results: Released plasmid complexes were transfected into stem cells and were expressed, which caused osteogenic differentiations of rat mesenchymal stem cells (rMSCs). SEM analysis showed excellent cell attachment. Bioactivity of plasmid rhBMP-2 was maintained in vivo, and the X-ray observation, histological analysis and immunohistochemistry (IHC) of bone tissue demonstrated that the bone healing in segmental femoral defects was enhanced by implantation of GAMs. Conclusions: Such biomaterials offer therapeutic opportunities in critical-sized bone defects.

scholarly journals Nucleotide Polymorphisms in the α2 Gene Define Multiple Alleles That Are Associated With Differences in Platelet α2β1 Density

Blood ◽  
1998 ◽  
Vol 92 (7) ◽  
pp. 2382-2388 ◽  
Author(s):  
Marcie Kritzik ◽  
Brian Savage ◽  
Diane J. Nugent ◽  
Sentot Santoso ◽  
Zaverio M. Ruggeri ◽  
...  
Keyword(s):  
Whole Blood ◽  
Type I Collagen ◽  
Type I ◽  
Nucleotide Polymorphisms ◽  
Coding Region ◽  
Platelet Surface ◽  
Multiple Alleles ◽  
Increased Risk ◽  
Allelic Differences

Three allelic differences in the α2 gene are associated with expression levels of the α2β1 integrin on the platelet surface. We have previously defined two linked silent polymorphisms in the α2 gene coding region at nucleotides 807 (C or T) and 873 (G or A). We have now identified one rarer nucleotide polymorphism in the coding region at nucleotide 837 (T or C) and four additional linked polymorphisms within the introns that flank these coding sequences. Moreover, we have determined that the alloantigenic Br polymorphism, which resides in a distal coding region at nucleotide 1648, is also linked to the 837 polymorphism. Thus, three α2 gene alleles, defined by eight nucleotide polymorphisms, have now been discovered. Allele 1 (807T/837T/873A/Brb) is associated with increased levels of α2β1; allele 2 (807C/837T/873G/Brb) and allele 3 (807C/837C/873G/Bra) are each associated with lower levels of α2β1. Finally, we also show here that the rate of platelet attachment to type I collagen in whole blood under conditions of high shear rate (1,500/s) is proportional to the density of α2β1 receptors on the platelet surface. Thus, the density of platelet α2β1 could have an important impact on platelet adhesion to collagen in whole blood and therefore on platelet function in vivo, contributing to an increased risk of thrombosis or to bleeding in relevant disease states.

Type VI collagen induces cardiac myofibroblast differentiation: implications for postinfarction remodeling

2006 ◽  
Vol 290 (1) ◽  
pp. H323-H330 ◽  
Author(s):  
Jennifer E. Naugle ◽  
Erik R. Olson ◽  
Xiaojin Zhang ◽  
Sharon E. Mase ◽  
Charles F. Pilati ◽  
...  
Keyword(s):  
Cardiac Fibrosis ◽  
Type I Collagen ◽  
In Vivo Model ◽  
Type Iii Collagen ◽  
Type I ◽  
Myofibroblast Differentiation ◽  
Type Vi Collagen ◽  
Collagen Substrate ◽  
Type Iii

Cardiac fibroblast (CF) proliferation and differentiation into hypersecretory myofibroblasts can lead to excessive extracellular matrix (ECM) production and cardiac fibrosis. In turn, the ECM produced can potentially activate CFs via distinct feedback mechanisms. To assess how specific ECM components influence CF activation, isolated CFs were plated on specific collagen substrates (type I, III, and VI collagens) before functional assays were carried out. The type VI collagen substrate potently induced myofibroblast differentiation but had little effect on CF proliferation. Conversely, the type I and III collagen substrates did not affect differentiation but caused significant induction of proliferation (type I, 240.7 ± 10.3%, and type III, 271.7 ± 21.8% of basal). Type I collagen activated ERK1/2, whereas type III collagen did not. Treatment of CFs with angiotensin II, a potent mitogen of CFs, enhanced the growth observed on types I and III collagen but not on the type VI collagen substrate. Using an in vivo model of myocardial infarction (MI), we measured changes in type VI collagen expression and myofibroblast differentiation after post-MI remodeling. Concurrent elevations in type VI collagen and myofibroblast content were evident in the infarcted myocardium 20-wk post-MI. Overall, types I and III collagen stimulate CF proliferation, whereas type VI collagen plays a potentially novel role in cardiac remodeling through facilitation of myofibroblast differentiation.

Overexpression of Long Non-Coding RNA AP001505.9 Inhibits Dedifferentiation in Human Hyaline Chondrocyte

2020 ◽  
Author(s):  
Lin Chen ◽  
Jinying Xu ◽  
Shuang Lv ◽  
Yan Zhao ◽  
Dongjie Sun ◽  
...  
Keyword(s):  
Type I Collagen ◽  
Expression Profiles ◽  
Type I ◽  
Pellet Culture ◽  
Real Time Quantitative Pcr ◽  
Non Coding Rna ◽  
In Situhybridization ◽  
Chondrocyte Implantation

Abstract Background: Autologous chondrocyte implantation (ACI) requires a large number ofhuman hyaline chondrocytes. Unfortunately, human hyaline chondrocytes oftenundergo dedifferentiation in vitro. Long non-coding RNAs (lncRNA) play aregulatory role in gene expression in many pathological and physiological processes.However, their role in human hyaline chondrocyte dedifferentiation remains unclear.This study aimed to investigate the expression profiles of lncRNAs in human hyalinechondrocyte dedifferentiation.Methods: Human hyaline chondrocytes were cultured in vitro and screened for theoccurrence of dedifferentiation using real-time quantitative PCR (qPCR),immunofluorescence, and western blotting. The expression profiles of lncRNAs andmRNAs during dedifferentiation were analyzed by microarray analysis and real-timeqPCR. We used pellet culture to redifferentiate chondrocytes and the expression ofrelated lncRNAs were assessed. The function of lncRNA AP001505.9(ENST00000569966) was determined by overexpression, fluorescence in situhybridization, competing endogenous RNA (ceRNA) analysis, and double luciferaselabeling.Results: We probed human hyaline chondrocytes dedifferentiation and identified 334upregulated and 381 downregulated lncRNAs. The expression of downregulatedlncRNA AP001505.9 in dedifferentiation was reversed by pellet culture. Theoverexpression of AP001505.9 inhibited dedifferentiation by promoting theexpression of SRY-Box transcription factor 9 (SOX-9) and inhibiting the expressionof type I collagen (COL1) both in vitro and in vivo.Conclusion: This study reveals for the first time the expression profiles of lncRNAsin human hyaline chondrocyte dedifferentiation, thereby providing a new perspectivefor exploring the potential mechanism of chondrocyte dedifferentiation.

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