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Principles and Biological Pathways to Tissue Regeneration: The Tissue Regenerative Niche
Published in Claudio Migliaresi, Antonella Motta, Scaffolds for Tissue Engineering, 2014
Ranieri Cancedda, Claudia Lo Sicco
and tumour TNF-alpha secreted by inflammatory cells that have a chemotactic effect on other inflammatory cells and on the recruitment of mesenchymal cells [Kon et al., 2001]. Other secreted growth and differentiation factors, such as TGF-beta superfamily including bone morphogenetic protein (BMP), as well as platelet-derived growth factor (PDGF), FGFs, and IGF, orchestrate crucial events for chondro-osteogenesis, including mesenchymal and osteoprogenitor cell chemotaxis, proliferation and differentiation, and extracellular matrix ossification. Finally, other important signaling molecules are the angiogenic factors such as VEGFs and Angiopoietin 1 and 2. VEGFs are essential mediators of neoangiogenesis and endothelial-cell specific mitogens. Angiopoietin 1 and 2 are regulatory vascular morphogenetic molecules related to the formation of larger vessels and development of collateral branches from existent vessels.
Overview of Angiogenesis: Molecular and Structural Features
Published in Robert J. Gropler, David K. Glover, Albert J. Sinusas, Heinrich Taegtmeyer, Cardiovascular Molecular Imaging, 2007
Arye Elfenbein, Michael Simons
The signaling molecules most implicated in this process of vessel remodeling are the angiopoietins, ligands that bind to two unique tyrosine kinases named Tie1 and Tie2. Although four distinct ligands have been identified (Ang-1–4), Ang-1 and Ang-2 are best understood with respect to their effects on vascular remodeling. The first insights into the involvement of angiopoietins in this role were generated by studies of Ang-1 knockout mice, which develop a normal primary vascular system that does not undergo subsequent remodeling (27).
Biomimetic Microsystems for Blood and Lymphatic Vascular Research
Published in Hyun Jung Kim, Biomimetic Microengineering, 2020
There are several families of proteins, ligands, and receptors that work in junction to tightly regulate the formation of blood vessels (Figure 2.1d). One of the signaling molecules that regulates vessel formation is vascular endothelial growth factor (VEGF). In mammals, the VEGF family members include VEGF-A, VEGF-B, VEGF-C, VEGF-D, and placental growth factor (PlGF) (Shibuya 2011). Among these, VEGF-A has been shown to be the most important player in blood vessel formation, as loss of a single allele of VEGF-A can cause vascular defects during embryogenesis (Carmeliet et al. 1996). VEGF-A signaling is mediated through the receptor tyrosine kinase VEGFR2 (KDR or FLK1), while the secreted soluble VEGFR1 (FLT1) acts as a ligand trap to antagonize VEGF-A signaling. Another family of proteins that regulates maturation of blood vessel is Angiopoietin (Ang 1 and Ang 2). During angiogenesis and vascular remodeling, Ang 2 is expressed in endothelial cells and disrupts the attachment of perivascular cells to the endothelial cells during angiogenesis (Fagiani and Christofori 2013). The superfamily of fibroblast growth factors (FGFs) exerts several biological functions, including angiogenesis and vessel formation. FGFs can act on endothelial cells directly or activate surrounding cells to promote angiogenesis (Beenken and Mohammadi 2009). FGF-2 in the protein family was first discovered as an angiogenic factor. However, FGF-2 and FGF-1 deficiency does not lead to vascular defects, suggesting that there is a redundancy in the FGF superfamily proteins (Beenken and Mohammadi 2009). Notch and Wnt signaling pathways are also playing essential roles in the formation of blood vessels. As mentioned earlier, tip-stalk cell formation and shuffling are mediated through the VEGF and DLL4-Notch signaling axis (Jakobsson et al. 2010). Notch can also activate Wnt signaling in proliferating stalk cells, and at the same time, the Wnt can reciprocally activate Notch (Corada et al. 2010, Phng et al. 2009).
Core genes in lung adenocarcinoma identified by integrated bioinformatic analysis
Published in International Journal of Environmental Health Research, 2023
Liu Yang, Qi Yu, Yonghang Zhu, Manthar Ali Mallah, Wei Wang, Feifei Feng, Qiao Zhang
To predict the protein interactions and explore the relationship between the DEGs, STRING was utilized. The results uncovered that a total of 72 nodes and 117 edges were involved in the PPI network (Figure 3(a)). The ten highest scoring nodes were calculated as the core genes by using CytoHubba in Cytoscape. The top ten genes were identified as shown in Figure 3(c). Core genes with neighbors containing 37 nodes and 85 edges are shown in Figure 3(b). Among these core genes, secreted phosphoprotein 1 (SPP1), collagen type I alpha 1 chain (COL1A1) and thrombospondin 2 (THBS2) were upregulated. Von Willebrand factor (VWF), platelet and endothelial cell adhesion molecule 1 (PECAM1), TEK receptor tyrosine kinase (TEK), angiopoietin 1 (ANGPT1), secretoglobin family 1A member 1 (SCGB1A1), CD36 molecule (CD36), and SPARC like 1 (SPARCL1) were downregulated.
Applications and hazards associated with carbon nanotubes in biomedical sciences
Published in Inorganic and Nano-Metal Chemistry, 2020
Ali Hassan, Afraz Saeed, Samia Afzal, Muhammad Shahid, Iram Amin, Muhammad Idrees
Plasmid DNA, the first type of nucleic acid that was successfully transformed in vitro by making use of CNTs. Both SWCNTs and MWCNTs have been utilized as a plasmid delivery agent when functionalized chemically with amine groups, polyethyleneimine and polyamidoamine hybrids.[60–62] Recently, CNTs have been demonstrated for in vivo delivery of plasmid, in the form of nanoparticle-CNT hybrids, in a canine model of restenosis. The nanoparticle-CNT hybrids consist of poly-acrylic acid wrapped to SWCNTs that are hybridized with plasmid DNA containing nanoparticles. In that particular case, plasmid DNA encodes for vascular endothelial growth factor and angiopoietin-1. This complex was implanted into the hydrogel. As a result, bioactive hydrogel stents were created. The purpose of hydrogel is to act as protect layer and simultaneously deliver the nanoparticle-containing genes to the target site. The bioactive hydrogel stents were implanted intravenously into balloon-injured canine femoral artery. The results demonstrated an increase in re-endothelialization of injured arteries.[63]