Collagen is the predominant protein in animal bodies, constituting approximately 30% of the total

Most types of connective tissue contain fibrous strands of the protein collagen that add strength to connective tissue. Some examples of connective tissue include the inner layers of skin, tendons, ligaments, cartilage, areolar, adipose bone and fat tissue. In addition to these more recognizable forms of connective tissue, blood is also considered a form of connective tissue.

58) Connective tissues that possess a large quantity of collagen fibers often provide the framework for organs such

Thinner, more darkly stained elastic fibers composed of the protein elastin can also be seen. The principal type of cells seen are lightly-staining fibroblasts that secrete the matrix materials.

Collagen is a form

The second type of tissue found in the body is connective tissue. They lie beneath the epithelial tissue helping to connect different part of the internal structure, the cells are more widely separated from each other then in epithelial tissue. The intercellular substance known as the matrix is found in considerably large amounts. Within the matrix there are usually fibres which may be a jelly like consistency or dense and rigid depending on the type, function and positioning of the tissue. Theses fibres form a supporting system for cells to attach to. The major functions of connective tissue are to transport materials, give structural support and protection. The types of connective tissue that will be explained are blood, bone, cartilage, bone, areolar tissue and adipose tissue.

The nuclei of the cells that secrete the collagen fibers are indicated by the number 1. What type cells are these?

When TGase was knocked down, the HPT cells stared to migrate out of the tissue. The effect of extracellular of TGase activity was decreased in HPT culture with crude astakine supplementation (8). This studies strongly suggest that TGase activity is important for extracellular matrix (ECM) stabilization and decrease of its extracellular activity is mediated the hemocyte releasing from HPT. However, the role of astakine1 in TGase regulation still unclear. In crayfish, in addition to collagen IV (9), HPT tissue contains an abundant of clotting protein (unpublished data), which known as noncollagenous TGase substrate. This suggested that collagen and/or clotting may be involved in HPT cell renewal. In osteoblast, TGase activity has been reported to be an essential for an initial formation of a fibronectin-collagen network which subsequent affects to cell differentiation and mineralization of the cultures (10). In addition, 5-HT, a monoamine with a variety of physiological function as well as regulation of bone mass, has been determined to be an inhibitor of FXIIIa. 5-HT treatment resulted in directly inhibit FXIIIa mediate crosslinking of plasma fibronectin and leads to decreasing the stabilization of extracellular matrix networks (11).

Tendons are densely packed fibrous connective tissue. They are responsible for the transmission of mechanical forces from skeletal muscle to the bone; act as joint stabilizers and “shock absorbers” to reduce muscle damage. Tendons are able to resist tensile forces due to the organization of their matrix. They are composed of approximately 70% of water and 30% of dry matter including collagen and a non-collagenous matrix. The predominant collagen present within the tendon is type I collagen, nevertheless it is also found small amounts of type II, III, IV and V collagen[1]. On the other hand, the non-collagenous matrix of the tendon contains a wide range of glycoproteins such as proteoglycans and other small molecules[2].

Proteins are polymeric chains that are built from monomers called amino acids. All structural and functional properties of proteins derive from the chemical properties of the polypeptide chain. There are four levels of protein structural organization: primary, secondary, tertiary, and quaternary. Primary structure is defined as the linear sequence of amino acids in a polypeptide chain. The secondary structure refers to certain regular geometric figures of the chain. Tertiary structure results from long-range contacts within the chain. The quaternary structure is the organization of protein subunits, or two or more independent polypeptide chains.

Type I collagen clearly contributes to the integrity and strength of bone matrix, and defects in its production leads to bone of poor quality, susceptible to fracture( Kini and Nandeesh 2012). Type I collagen is a triple helical structure consisting of two identical a1 chains and one a2 chain with a non-helical region where the N-telopeptide and C-telopeptide join to the crosslinks (Brown et al.,2009; Bergmann et al., 2009 ; Seibel 2005). During type I collagen synthesis, pro-peptides are released both from the N-terminal and C-terminal ends of the procollagen molecule, after the three individual alpha chains have created the triple helix, which will become part of the collagen fibril( Kini and Nandeesh

Abnormal immune function in both forms of scleroderma is defined as an alteration in cytokine function and the activation of T-cells with the presence of auto-antibodies (Woo, Laxer & Sherry, 2007). IL-4 and IL-6 stimulate collagen synthesis by the activation of fibroblasts, increasing production of collagen type I and III. Other factors that are thought to mediate fibroblast activation include growth factors such as platelet-derived growth factor and connective tissue growth factors. Additionally, the production of tissue inhibitors such as matrix metalloproteases has been noticeably upregulated therefore, fibrosis is thought to be a result of not only the increased levels of collagen production but also the decreased levels of cellular matrix turnover (Mayes, 2014). Localised scleroderma will appear with dyspigmented, atrophic sclerotic lesions generally present on the extremities, back, trunk, neck, head and scalp, where as the first manifestation present in systemic scleroderma is oedema of the hands, causing restricted movement followed by skin

The cause of this disease from one of the genes that tells the body how to make a specific protein does not function. The protein (type 1 collagen) is a major component of connective tissues in bones. The protein is also important for forming ligaments, teeth, and the white outer tissue of the eyeballs called sclera. In a majority of cases the defective gene is inherited

About one quarter of all the protein in your body is collagen. It is a major structural material that forms molecular cables to strengthen the tendons and resilient sheets that support the skin and internal organs. Bones and teeth are made by adding mineral crystals to collagen. Collagen provides structure to our bodies, protecting and supporting the softer tissues and connecting them with the skeleton. But, in spite of its critical function in the body, collagen is a relatively simple protein.

Articular cartilage is organized into four different layers/zones: superficial (tangential), middle (transitional), deep (radial), and calcified. The cellular structure of each layer is slightly different and corresponds to its role and type of force that it can withstand; the superficial layer has parallel alignment to withstand shear forces, the middle layer begins to resist compressive forces with a more oblique orientation, and the deep layer has a perpendicular alignment that largely resists compression. The calcified layer is where the cartilage connects to bone tissue, and is separated from the deep layer by the tidemark, which is a region of parallel-oriented fibers to reduce shear force. Since grading of chondral lesions (commonly on a Grade 0-4 scale) is based upon the depth of injury, it is important to understand these specialized

Bettelheim, Brown, Campbell and Farrell assert that polypeptide chains do not extend in straight lines but rather they fold in various ways and give rise to a large number of three-dimensional structures (594). This folding or conformation of amino acids in the localized regions of the polypeptide chains defines the secondary structure of proteins. The main force responsible for the secondary structure is the non-covalent