The Induction of Bone Formation and the Osteogenic Proteins of the Transforming Growth Factor-β Supergene Family
Ugo Ripamonti in The Geometric Induction of Bone Formation, 2020
Bone as a skeletal armour developed as a biological and physical defence against the predaceous habits of the eurypterids, largely feeding on the early vertebrate “bony fishes” at the evolutionary beginning of the vertebrates. It seems likely that the eurypterids’ aggressive feeding on the evolutionary beginning of the vertebrates “was primarily responsible for the development of the vertebrate bony armour”. Columnar condensations of chondroblastic cells are to be found in the pleiotropic uniqueness of the cartilaginous growth plate, a fundamental compartmentalized biological system of growth that masterminds the tri-dimensional growth of the mammalian axial skeleton that forms through endochondral osteogenesis via the cartilage anlage. Primarily, membranous osteogenesis originates after the induction of mesenchymal condensations populated by contiguous osteoblasts that later continuously secrete bone matrix as yet to be mineralized, or osteoid, around invading and supporting central blood vessels. In the bone matrix, molecular signals are in solution, interacting with the insoluble signal of the extracellular matrix.
Skeletal Embryology and Limb Growth
Manoj Ramachandran, Tom Nunn in Basic Orthopaedic Sciences, 2018
During the early stages of development, the embryo has a laminar structure consisting of three different germ cell layers, from which specific systems will develop. The limb buds first appear at the end of the fourth week of development, with the forelimbs preceding the hindlimbs by 1-2 days. The anteroposterior axis (thumb to little finger) is regulated by the zone of polarizing activity (ZPA), a mass of cells within the posterior aspect of the limb bud. Amniotic band syndrome (ABS) is a congenital disorder believed to result from the entrapment of fetal limbs or organs within intrauterine fibrous amniotic bands, produced by partial rupture of the amniotic sac. The physis is a structure consisting of chondrocytes arranged in a highly ordered, layered fashion within an extracellular matrix in line with the longitudinal axis of the bone. Altering the forces acting upon the physis affects its activity, with compression retarding growth (Hueter-Volkmann principle).
Structure and Function of Cartilage
Kyriacos A. Athanasiou, Eric M. Darling, Grayson D. DuRaine, Jerry C. Hu, A. Hari Reddi in Articular Cartilage, 2017
This chapter covers the structure, composition, and function of articular cartilage, at the cell and extracellular matrix levels. All chondrocytes within articular cartilage share common traits with respect to gene and protein expressions, surface markers, and cell metabolism. The role of microtubules in intracellular transport is elegantly demonstrated in the assembly of the mitotic spindle, a structure that results in intracellular movement and segregation of replicated DNA into two daughter cells during mitosis. The territorial matrix exhibits higher concentration of proteoglycans than surrounding extracellular matrix, as well as having finer collagen structure. The biochemical structure of the matrix, both fluid and solid fractions, is intimately linked to mechanical function of cartilage. Structurally, intermediate filaments are 10 nm in diameter and "intermediate" in size, being smaller than microtubules but wider than actin microfilaments. In eukaryotic cells, cytoskeleton is comprised of three different filament types that can polymerize from soluble protein monomers into three-dimensional network that couples intracellular components to extracellular stimuli.
Constructive Soft Tissue Remodelling with a Biologic Extracellular Matrix Graft: Overview and Review of the Clinical Literature
Published in Acta Chirurgica Belgica, 2007
The extracellular matrix directs all phases of healing following trauma or disease and is therefore nature’s ideal scaffold material. When used strategically to induce the repair and restoration of soft tissues following surgery, exogenous extracellular matrix scaffolds interact with surrounding tissues and cells to form a permanent repair without leaving behind a permanent material that can result in chronic inflammation or infection. Biomaterials derived from natural extracellular matrix, such as Surgisis® (Cook Medical Incorporated, Bloomington, IN, USA), provide the extracellular components necessary to direct the healing response, allow for the reconstruction of new, healthy tissue and restore mechanical and functional integrity to the damaged site. The 3-dimensional organization of these extracellular components distinguishes the Surgisis mesh from synthetic materials and is associated with better long-term repairs. The tissue response to this biologic mesh is discussed in the context of recent reports on successful clinical applications.
Regional Variability in the Time Course of TGF-β1 Expression, Cellular Proliferation and Extracellular Matrix Expansion following Arterial Injury
Published in Growth Factors, 1997
Wendy M. Creighton, Allen J. Taylor, David A. Dichek, Gang Dong, Anita B. Roberts, Andrew H. Schulick, Poonam Mannam, Renu Virmani
Transforming growth factor-β1 (TGF-β1) has been variably associated with the regulation of cellular proliferation and extracellular matrix expansion after arterial injury. We tested these associations in vivo in the rat carotid injury model. At 0, 3, 7, 14 and 28 days following arterial balloon injury, regional expression of TGF-β1 mRNA was assessed using in situ hybridization and the results compared to measures of cellular proliferation and extracellular matrix expansion. Both the TGF-β1 concentration measured in culture media of explanted carotid arteries and the quantitative in situ hybridization signal for TGF-β1 in arterial media and neointima were maximal at 14 days after balloon injury. However, medial cellular proliferation was maximal at 3 days whereas neointimal proliferation was maximal at 14 days and significantly greater than medial proliferation. Neointimal cell density declined significantly between 7 and 14 days, indicating the expansion of extracellular matrix; however, medial cell density was unchanged between 3 and 28 days after balloon injury. Thus, differences in the regional arterial wall relationships between the time course of cellular proliferation, extracellular matrix expansion and the level of TGF-β1 expression demonstrate in vivo variability in the response to TGF-β1.
Age associated communication between cells and matrix: a potential impact on stem cell-based tissue regeneration strategies
Published in Organogenesis, 2014
A recent paper demonstrated that decellularized extracellular matrix (DECM) deposited by synovium-derived stem cells (SDSCs), especially from fetal donors, could rejuvenate human adult SDSCs in both proliferation and chondrogenic potential, in which expanded cells and corresponding culture substrate (such as DECM) were found to share a mutual reaction in both elasticity and protein profiles (see ref. 1). It seems that young DECM may assist in the development of culture strategies that optimize proliferation and maintain “stemness” of mesenchymal stem cells (MSCs), helping to overcome one of the primary difficulties in MSC-based regenerative therapies. In this paper, the effects of age on the proliferative capacity and differentiation potential of MSCs are reviewed, along with the ability of DECM from young cells to rejuvenate old cells. In an effort to highlight some of the potential molecular mechanisms responsible for this phenomenon, we discuss age-related changes to extracellular matrix (ECM)'s physical properties and chemical composition.
Related Knowledge Centers
- Bowman Capsule
- Cell Wall
- Interstitial Fluid
- Endothelium
- Cell Membrane
- Podocytes
- Extracellular