scholarly journals Understanding the Mechanism of In Vitro Chondrogenesis Using a Coculture System for Generating a Tissue-engineered Cartilage Construct

2019 ◽  
Vol 7 ◽  
pp. 133
Author(s):  
Mary E. Ziegler ◽  
Alexandria M. Sorensen ◽  
Gregory R. D. Evans ◽  
Alan D. Widgerow
Keyword(s):  
Coculture System ◽  
Engineered Cartilage ◽  
Cartilage Construct

scholarly journals An Instrumented Bioreactor for Mechanical Stimulation and Real-Time, Nondestructive Evaluation of Engineered Cartilage Tissue

2012 ◽  
Vol 6 (2) ◽  
Author(s):  
Jenni R. Popp ◽  
Justine J. Roberts ◽  
Doug V. Gallagher ◽  
Kristi S. Anseth ◽  
Stephanie J. Bryant ◽  
...  
Keyword(s):  
Nondestructive Evaluation ◽  
Mechanical Stimulation ◽  
Ultrasonic Transducer ◽  
Testing Machine ◽  
Cartilage Tissue ◽  
Matrix Deposition ◽  
Intermittent Compression ◽  
Engineered Tissue ◽  
Engineered Cartilage

Mechanical stimulation is essential for chondrocyte metabolism and cartilage matrix deposition. Traditional methods for evaluating developing tissue in vitro are destructive, time consuming, and expensive. Nondestructive evaluation of engineered tissue is promising for the development of replacement tissues. Here we present a novel instrumented bioreactor for dynamic mechanical stimulation and nondestructive evaluation of tissue mechanical properties and extracellular matrix (ECM) content. The bioreactor is instrumented with a video microscope and load cells in each well to measure tissue stiffness and an ultrasonic transducer for evaluating ECM content. Chondrocyte-laden hydrogel constructs were placed in the bioreactor and subjected to dynamic intermittent compression at 1 Hz and 10% strain for 1 h, twice per day for 7 days. Compressive modulus of the constructs, measured online in the bioreactor and offline on a mechanical testing machine, did not significantly change over time. Deposition of sulfated glycosaminoglycan (sGAG) increased significantly after 7 days, independent of loading. Furthermore, the relative reflection amplitude of the loaded constructs decreased significantly after 7 days, consistent with an increase in sGAG content. This preliminary work with our novel bioreactor demonstrates its capabilities for dynamic culture and nondestructive evaluation.

scholarly journals Influence of in vitro maturation of engineered cartilage on the outcome of osteochondral repair in a goat model

2012 ◽  
Vol 23 ◽  
pp. 222-246 ◽  
Author(s):  
S Miot ◽  
◽  
W Brehm ◽  
S Dickinson ◽  
T Sims ◽  
...  
Keyword(s):  
In Vitro Maturation ◽  
Osteochondral Repair ◽  
Engineered Cartilage

scholarly journals e0139 The cardiomyogenic potential of cardiac stem cells in an in vitro coculture system

Heart ◽  
2010 ◽  
Vol 96 (Suppl 3) ◽  
pp. A45-A45
Author(s):  
W. Wei ◽  
Z. Marc-michael ◽  
G. Hui ◽  
B. Remus ◽  
K. Hajime ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cardiac Stem Cells ◽  
Coculture System

scholarly journals Comparative Analysis of EspF Variants in Inhibition of Escherichia coli Phagocytosis by Macrophages and Inhibition of E. coli Translocation through Human- and Bovine-Derived M Cells

2011 ◽  
Vol 79 (11) ◽  
pp. 4716-4729 ◽  
Author(s):  
Amin Tahoun ◽  
Gabriella Siszler ◽  
Kevin Spears ◽  
Sean McAteer ◽  
Jai Tree ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Cellular Localization ◽  
M Cells ◽  
Binding Assays ◽  
M Cell ◽  
Content Type ◽  
E Coli ◽  
Coculture System

ABSTRACTThe EspF protein is secreted by the type III secretion system of enteropathogenic and enterohemorrhagicEscherichia coli(EPEC and EHEC, respectively). EspF sequences differ between EHEC O157:H7, EHEC O26:H11, and EPEC O127:H6 in terms of the number of SH3-binding polyproline-rich repeats and specific residues in these regions, as well as residues in the amino domain involved in cellular localization. EspFO127is important for the inhibition of phagocytosis by EPEC and also limits EPEC translocation through antigen-sampling cells (M cells). EspFO127has been shown to have effects on cellular organelle function and interacts with several host proteins, including N-WASP and sorting nexin 9 (SNX9). In this study, we compared the capacities of differentespFalleles to inhibit (i) bacterial phagocytosis by macrophages, (ii) translocation through an M-cell coculture system, and (iii) uptake by and translocation through cultured bovine epithelial cells. TheespFgene fromE. coliserotype O157 (espFO157) allele was significantly less effective at inhibiting phagocytosis and also had reduced capacity to inhibitE. colitranslocation through a human-derivedin vitroM-cell coculture system in comparison toespFO127andespFO26. In contrast,espFO157was the most effective allele at restricting bacterial uptake into and translocation through primary epithelial cells cultured from the bovine terminal rectum, the predominant colonization site of EHEC O157 in cattle and a site containing M-like cells. Although LUMIER binding assays demonstrated differences in the interactions of the EspF variants with SNX9 and N-WASP, we propose that other, as-yet-uncharacterized interactions contribute to the host-based variation in EspF activity demonstrated here.

scholarly journals Functional properties of bone marrow-derived MSC-based engineered cartilage are unstable with very long-term in vitro culture

2014 ◽  
Vol 47 (9) ◽  
pp. 2173-2182 ◽  
Author(s):  
Megan J. Farrell ◽  
Matthew B. Fisher ◽  
Alice H. Huang ◽  
John I. Shin ◽  
Kimberly M. Farrell ◽  
...  
Keyword(s):  
Bone Marrow ◽  
In Vitro Culture ◽  
Functional Properties ◽  
Engineered Cartilage

Injectable self-crosslinking HA-SH/Col I blend hydrogels for in vitro construction of engineered cartilage

2018 ◽  
Vol 190 ◽  
pp. 57-66 ◽  
Author(s):  
Yafang Chen ◽  
Junhui Sui ◽  
Qing Wang ◽  
Yijia Yin ◽  
Jun Liu ◽  
...  
Keyword(s):  
Engineered Cartilage

scholarly journals Integrin β1 Gene Therapy Enhances in Vitro Creation of Tissue-Engineered Cartilage Under Periodic Mechanical Stress

2015 ◽  
Vol 37 (4) ◽  
pp. 1301-1314 ◽  
Author(s):  
Wenwei Liang ◽  
Chunhui Zhu ◽  
Feng Liu ◽  
Weiding Cui ◽  
Qing Wang ◽  
...  
Keyword(s):  
Mechanical Stress ◽  
Type Ii Collagen ◽  
Cell Types ◽  
Signal Pathways ◽  
Matrix Synthesis ◽  
Integrin Β1 ◽  
Chondrocyte Proliferation ◽  
Engineered Cartilage

Background/Aims: Periodic mechanical stress activates integrin β1-initiated signal pathways to promote chondrocyte proliferation and matrix synthesis. Integrin β1 overexpression has been demonstrated to play important roles in improving the activities and functions of several non-chondrocytic cell types. Therefore, in the current study, we evaluated the effects of integrin β1 up-regulation on periodic mechanical stress-induced chondrocyte proliferation, matrix synthesis and ERK1/2 phosphorylation in chondrocyte monolayer culture, and evaluated the quality of tissue-engineered cartilage constructed in vitro under periodic mechanical stress combined with integrin β1 up-regulation. Methods and Results: Our results revealed that under periodic mechanical stress, pre-treatment with integrin β1-wild type vector significantly enhanced chondrocyte proliferation and matrix synthesis and promoted ERK1/2 phosphorylation in comparison to mock transfectants. Furthermore, when chondrocytes were seeded in PLGA scaffolds, more accumulated GAG and type II collagen tissue were detected after Lv-integrin β1 transfection compared with sham controls exposed to periodic mechanical stress. In contrast, in the Lv-shRNA-integrin β1 group, the opposite results were observed. Conclusion: Our findings collectively suggest that in addition to periodic mechanical stress, integrin β1 up-regulation in chondrocytes could further improve the quality of tissue-engineered cartilage.

In Vitro Hematopoietic and Endothelial Cell Development From Cells Expressing TEK Receptor in Murine Aorta-Gonad-Mesonephros Region

Blood ◽  
1999 ◽  
Vol 93 (5) ◽  
pp. 1549-1556 ◽  
Author(s):  
Isao Hamaguchi ◽  
Xu-Ling Huang ◽  
Nobuyuki Takakura ◽  
Jun-ichi Tada ◽  
Yuji Yamaguchi ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Single Cell ◽  
Hematopoietic Cells ◽  
Hematopoietic Stem ◽  
Coculture System ◽  
Platelet Endothelial Cell Adhesion ◽  
Stromal Cell Line ◽  
Macrophage Colony

Recent studies have shown that long-term repopulating hematopoietic stem cells (HSCs) first appear in the aorta-gonad-mesonephros (AGM) region. Our immunohistochemistry study showed that TEK+cells existed in the AGM region. Approximately 5% of AGM cells were TEK+, and most of these were CD34+ and c-Kit+. We then established a coculture system of AGM cells using a stromal cell line, OP9, which is deficient in macrophage colony-stimulating factor (M-CSF). With this system, we showed that AGM cells at 10.5 days postcoitum (dpc) differentiated and proliferated into both hematopoietic and endothelial cells. Proliferating hematopoietic cells contained a significant number of colony-forming cells in culture (CFU-C) and in spleen (CFU-S). Among primary AGM cells at 10.5 dpc, sorted TEK+ AGM cells generated hematopoietic cells and platelet endothelial cell adhesion molecule (PECAM)-1+ endothelial cells on the OP9 stromal layer, while TEK− cells did not. When a ligand for TEK, angiopoietin-1, was added to the single-cell culture of AGM, endothelial cell growth was detected in the wells where hematopoietic colonies grew. Although the incidence was still low (1/135), we showed that single TEK+ cells generated hematopoietic cells and endothelial cells simultaneously, using a single-cell deposition system. This in vitro coculture system shows that the TEK+ fraction of primary AGM cells is a candidate for hemangioblasts, which can differentiate into both hematopoietic cells and endothelial cells.

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