Chondrogenesis
Definition
Chondrogenesis is the process of cartilage formation by multipotent stem cells of the third germ layer - the mesoderm. The stem cells at early stage of chondrogenic development, after receiving a differentiation signal, becomes a cartilage progenitor cell and loses the ability to differentiate into other cells of mesenchymal origin. Mesenchymal stem cells differentiate into cartilage progenitor cells, chondroblasts, which are characterized by the ability to create a functional extracellular matrix composed of collagen fibers, elastin, and proteoglycans. Chondrocytes formed after differentiation, together with the amorphous intercellular matrix, contribute to formation of various type of cartilage tissue [1]. A characteristic feature of cartilage tissue is the lack of blood and lymph vessels, and the nourishment of chondrocytes occurs by diffusion from the perichondrium. There are no nerve endings in the cartilage tissue.
There are three types of cartilage tissue:
- Hyaline cartilage - tissue about 2-4 mm thick, composed mainly of type II and type IX collagen, proteoglycans, chondrocytes and water (65-80%). Hyaline cartilage constitute a component of articular cartilage, larynx, cartilaginous rings of the trachea and bronchi, nasal septum [2].
- Fibrocartilage - consists of a very dense network of collagen fibers (mainly type I collagen) and is a structural component of tendons, ligaments, pubic symphysis and intervertebral cartilage [3].
- Elastic cartilage - mainly composed of elastin and type II collagen, and is characterized by high flexibility and deformability. The elastic cartilage constitute a component of ear canal, Eustachian tube, epiglottis and small cartilages of the larynx.
Cartilage is exposed to a numerous damages caused by physical factors (excessive exercise) and some autoimmune diseases. If the degenerative processes prevailed over the regenerative processes, the cartilage tissue becomes permanently damaged and dysfunctional. The regenerative processes can be supported by cellular therapy using mesenchymal stem cells differentiated into chondrocytes in vitro [4][5].
Bibliografia
- ↑ Woods A, Wang G, Beier F. Regulation of chondrocyte differentiation by the actin cytoskeleton and adhesive interactions. J Cell Physiol. 2007 Oct;213(1):1-8. doi: 10.1002/jcp.21110
- ↑ Alice J. Sophia Fox M, Asheesh Bedi, MD, and Scott A. Rodeo, MD. The Basic Science of Articular Cartilage. Sports Health. 2009:461-8
- ↑ Benjamin M, Ralphs JR. Biology of fibrocartilage cells. Int Rev Cytol. 2004;233:1-45. doi: 10.1016/S0074-7696(04)33001-9
- ↑ Solchaga LA, Penick KJ, Welter JF. Chondrogenic differentiation of bone marrow-derived mesenchymal stem cells: tips and tricks. Methods Mol Biol. 2011;698:253-78. doi: 10.1007/978-1-60761-999-4_20
- ↑ Wu L, Bluguermann C, Kyupelyan L, Latour B, Gonzalez S, Shah S, Galic Z, Ge S, Zhu Y, Petrigliano FA, Nsair A, Miriuka SG, Li X, Lyons KM, Crooks GM, McAllister DR, Van Handel B, Adams JS, Evseenko D. Human developmental chondrogenesis as a basis for engineering chondrocytes from pluripotent stem cells. Stem Cell Reports. 2013 Dec 12;1(6):575-89. doi: 10.1016/j.stemcr.2013.10.012