Chondrosarcoma
Dongyou Liu in Tumors and Cancers, 2017
Like other connective tissues, cartilage is composed of cells and extracellular matrix. The cells of cartilage include chondroblasts and chondrocytes (chondro = cartilage). Chondroblasts secrete matrix and fibers, become trapped inside and mature into chondrocytes. Chondrocytes divide and form “nests” of two to four cells in the enclosed compartments (called lacunae or little lakes or small pits) in the matrix. The extracellular matrix of cartilage comprises aggregating GAG chondroitin sulfate (or aggrecan) and collagen or collagen-elastin fibers. Most cartilage is covered by a dense irregular connective tissue (called perichondrium), consisting of collagen-producing fibroblasts (in the outer layer) and chondroblasts in the inner layer. In contrast to highly vascularized and rigid bone, cartilage is avascular (and thus relies on long-range diffusion from nearby capillaries in the perichondrium for nourishment), flexible, semirigid, and resistant to compressive forces. Cartilage is present in the ear, walls of airways (nose, trachea, larynx, and bronchi), and joints (articular cartilage).
Concavities of Crystalline Sintered Hydroxyapatite-Based Macroporous Bioreactors Initiate the Spontaneous Induction of Bone Formation
Ugo Ripamonti in The Geometric Induction of Bone Formation, 2020
In unique experimentation in the Carcharhiniform selachian Carcharhinus obscurus shark, coral-derived macroporous constructs, 20 mm in length, 11 mm in diameter, were implanted in the dorsal muscles of a number of adolescent C. obscurus (Ripamonti 2018b; Ripamonti et al. 2018). Retrieved specimens, often damaged and crushed by the powerful muscular activity of the selachian fishes, were processed for histological analyses, and one control specimen was amenable to proper histological processing and sectioning with successful staining of the newly formed tissues within the macroporous spaces (Fig. 5.18). Chondrogenesis developed within the macroporous spaces without any application of soluble morphogenetic signals (Fig. 5.18). Panel (a) shows the induction of cartilage material directly against the calcium phosphate-based bioreactor (dark blue arrow) with columns of progressively differentiating chondroblasts (lightblue arrows), patterning the newly formed cartilage as in mammalian embryonic development (Reddi 2000; Ripamonti 2017; Ripamonti et al. 2018). Our published paper speculated that the micro-inductive micro-environment of the coral-derived macroporous bioreactors engineers cartilaginous columnar condensations as seen in the mammalian growth plate counterpart (Ripamonti et al. 2018). Panel (b) shows the induction of cartilage (Fig. 18b white arrow) detailing the columnar arrangement of chondroblasts/chondrocytes as in the mammalian growth plate (Fig. 18b light blue arrow).
Physical and functional growth and development
Nick Draper, Helen Marshall in Exercise Physiology, 2014
Nearly all bones begin life as cartilage. Both are forms of connective tissue but cartilage is more elastic in nature and therefore less rigid. During the formation of cartilage, chondroblasts (cartilage forming cells) become entrapped in their own network or matrix and develop into chondrocytes (cartilage cells). Most of the skeletal cartilage is replaced by bone as the body develops in a process called ossification. Three types of bone cell are involved in the growth, repair and remodeling of bone tissue. In a similar fashion to cartilage, bone-forming osteoblasts, which combine calcium and phosphorus to produce hydroxyapatite crystals (the mineralised form of bone), become osteocytes when entrapped in their own mineral network. Osteoclasts (from the Greek words for bone and broken), the third form of bone cell, are responsible for the removal and resorption of unwanted bone or the breakdown of bone when the minerals are required elsewhere in the body. While osteocytes are trapped within the matrix of the bone, osteoclasts, which are large multinucleated cells, are free to move along the bone surface as they remove and repair damaged sections of the bone matrix.
Specification of Sprouty2 functions in osteogenesis in in vivo context
Published in Organogenesis, 2019
Barbora Vesela, Eva Svandova, Maria Hovorakova, Renata Peterkova, Adela Kratochvilova, Martina Pasovska, Alice Ramesova, Herve Lesot, Eva Matalova
Transgenic mice lacking SPRY and SPRED (Sprouty-related, EVH1 domain-containing proteins) family proteins show abnormalities in endochondral (long) bones including a decreased bone growth (achondroplasia-like phenotype) and decreased trabecular bone mass.3–5 Endochondral bones, unlike the intramembranous ones, involve a chondrogenic developmental step. The developing growth plate may be divided into three compartments: an external fibrous tissue surrounding the periphery, a cartilaginous, and a bony tissue. The cartilaginous part consists of several zones, where chondrocytes differentiate towards the diaphysis: the resting zone, where a pool of less differentiated chondroblasts is localized, proliferating zone, where chondroblasts multiply and further differentiate, and zone of hypertrophy undergoing calcification, degradation and replacement by osseous tissue. The calcifying matrix of cartilage starts to be removed by osteoclasts/chondroclasts in the line of erosion, and the formation of the primary spongiosa involves a cooperation between osteoblasts and osteoclasts in the zone of ossification.6
Cell membrane capsule: a novel natural tool for antitumour drug delivery
Published in Expert Opinion on Drug Delivery, 2019
Hai Zou, Jing Zhu, Dong-Sheng Huang
Using chemicals to stimulate cells is one of the important methods to produce EVs. Saha et al. reported that the number of EVs, mostly exosomes, secreted by primary monocytes and THP-1 mononuclear cells was increased in the presence of alcohol, a phenomenon which showed a concentration and time dependence [131]. Increased intracellular calcium levels in erythrocytes could cause EV biogenesis [132]. In addition, ATP depletion and exposure to membranotropic and haemolytic agents triggered similar effects [80,82]. Cytochalasin B (CB) was investigated by some researchers to induce EV production by cells [34,133,134]. CB interferes with cytokinesis, but not with nuclear division, to reversibly induce branching of cells [134]. While capable of inducing branching in many immature cell types such as myoblasts, fibroblasts, and non-encapsulated chondroblasts, these changes were not observed in more mature cell types such as myotubular myoblasts, erythrocytes, amnion cells, encapsulated chondroblasts, and HeLa cells. Pick et al. successfully produced EVs from cells in their study investigating the effects of CB on human embryonic kidney HEK293 cells [34]. Treatment with CB resulted in the appearance of tubular protrusions in these cells. Agitation of CB-treated cells led to the release of EVs with maintained orientation and functional activity of cell surface receptors, ion pumps and cytosolic proteins.
Exposure to tobacco smoke increases bone loss in spontaneously hypertensive rats
Published in Inhalation Toxicology, 2018
Jingyi Xu, Xing Qiu, Zhou Liang, Suzette Smiley-Jewell, Faqiang Lu, Mang Yu, Kent E. Pinkerton, Dewei Zhao, Bingyin Shi
Adipocytes, as well as osteoblasts and chondroblasts originate from the differentiation of bone marrow stromal cells (MSCs) (Fridenshtein et al., 1968; Gimble, 1990). Increased marrow adipose tissue (MAT) has been linked to osteoporosis and increased risk of fracture (Verma et al., 2002; Naveiras et al., 2009; Fazeli et al., 2013; Schwartz, 2015). Although the underlying mechanism has not been fully elucidated, the interrelationship between adipocytes and osteoblasts within the bone marrow was assumed to be, at least partially, involved in such causal relationship (Rosen et al., 2009). Our results linked increased number of adipocytes in the trabecular bone marrow with exposure to tobacco smoke, either in normotensive or hypertensive rats. The combinative effect of hypertension and exposure to tobacco smoke also contributed to a significantly decreased number of trabecular osteocytes, suggesting inhibited osteogenesis. Within the trabecular milieu, increased adipocyte population contributes to a biomechanical environment that erects detrimental effect on osteogenic differentiation of trabecular mesenchymal stem cells (Discher et al., 2005; David et al., 2007; Gurkan and Akkus, 2008; Vaughan et al., 2015; Chen et al., 2016), in addition to its lipotoxic effect on trabecular osteoblasts (Maurin et al., 2000; Elbaz et al., 2010; Gunaratnam et al., 2014). Therefore, tobacco smoke exposure-induced increase in the number of adipocytes in trabecular marrow could adversely influence the functional expression of trabecular osteoblasts as well as osteogenesis, reflected by reduced BMD and trabecular parameters.
Related Knowledge Centers
- Cartilage
- Chondrogenesis
- Mesenchyme
- Perichondrium
- Chondrocyte
- Endochondral Ossification
- Osteoblast
- Progenitor Cell
- Matrix
- Fat