Synthesis collagen

C Ascorbic acid Coenzyme in hydroxylation of proline and lysine in collagen synthesis antioxidant enhances absorption of iron Scurvy—impaired wound healing, loss of dental cement, subcutaneous hemorrhage... 

Signs of vitamin C deficiency in scurvy include skin changes, fragifity of blood capillaries, gum decay, tooth loss, and bone fracmre, many of which can be attributed to deficient collagen synthesis. 

Choi et al., 2001 Murine osteoblastic MC3T3 cells Soybean ethanol extract (0.05 g/1) stimulated osteoblastic function (DNA synthesis, collagen synthesis). 

The human lens is rich in ascorbate, which is required for normal collagen synthesis and acts as a water-soluble antioxidant, reacting rapidly with superoxide, hydroxyl and peroxyl radicals. However, ascorbic acid can undergo auto-oxidation and, at certain concentrations, can form hydroxyl radicals with hydrogen peroxide in the presence of light and riboflavin as described above (Delaye and Tardieu, 1983 Ueno et al., 1987). 

Recently, the notion that the chronicity of inflammation may not actually drive the fibrogenic process has been widely appreciated (Tables 1, 2, and 3). Some propose that it is indeed the alteration of the mesenchymal cell phenotypes that disrupts the balance between collagen synthesis and degradation in the wound-healing process, highlighted by clinical evidence that shows unsuccessful treatment of fibrosis with anti-inflammatory or immunosuppressive drugs (18,19). One scenario is that mesenchymal cells (myofibroblasts and fibroblasts) are phenotypically altered and thus do not undergo apoptosis after resolution. 

Inhibition of IFN-y entails inhibition of fibroblast proliferation and differentiation, subsequent collagen synthesis, and increased expression of MMP-1 to promote degradation of matrix (105). IFN-y also triggers robust T-lymphocyte... 

Haehling, E., Niederkorn, J.Y. and Stewart, G.L. (1995) Trichinella spiralis and Trichinella pseudospiralis induce collagen synthesis by host fibroblasts in vitro and in vivo. InternationalJournal of Parasitology 25, 1393—1400. 

Co-expression of the human a- and p-subunits in the yeast Pichea pastoralis produces only trace amounts of active tetramer, with the majority being present in an unassembled form. Co-expression with human type III collagens, however, increases this assembly level tenfold. This indicates that collagen synthesis and the formation of an active prolyl 4-hydroxylase complex are mutually dependent processes (Vuorela et al, 1997). A similar observation has been noted for baculovirus encoded enzymes in insect cells (Lamberg et al, 1996). These findings support the hypothesis that this unusual control mechanism may be a common feature of collagen synthesis in all cell types. 

The principal cells in bone are the osteoclasts and osteoblasts. Osteoclasts, the cells responsible for resorption of bone, are derived from hematopoietic stem cells. Osteoblasts are derived from local mesenchymal cells. They are the pivotal bone cell, responsible for bone formation. Skeletal tissues are remodelled throughout a lifetime, alternating resorption phases by osteoclasts with periods of intense collagen synthesis. This balance is under the control of mechanical and hormonal stimuli, which ensure the appropriate performance of the bone. Skeletal tissues have three... 

In other studies, mast cells have been shown to be abundant in the marrow of osteoporotic patients, and heparin, which is contained within the secretory granules of connective tissue (peritoneal)-type mast cells, has been shown to enhance bone resorption and to inhibit bone-cell replication and collagen synthesis in vitro [130]. Moreover, heparin is known to bind growth factors such as fibroblast growth factor and may therefore be important in limiting their availability [134], Taken together, these various studies suggest a possible involvement of mast cells in the homeostasis of bone, but much more work is needed before any definitive conclusions can be drawn. 

Genetically determined abnormalities in GAG or collagen synthesis lead to joints becoming easily dislocated, hyperextendable and hyperelastic ( double-jointed ),... 

Hussain, M. Z., M. G. Mustafa, R. B. Rucker, and C. E. Cross. Lung collagen synthesis as stimulated by low level ozone exposure. Clin. Res. 23 138A, 1975. (abstract)... 

Lupulescu AP, Birmingham DJ. 1975. Effect of lipid solvents on protein, DNA, and collagen synthesis in human skin An electron microscopic autoradiographic study. J Invest Dermatol 65(5) 419-422. 

This solid phase radiofluorination was also shown efficient for the stereospecific and semi-automated preparation of cis- and fran5-[4- F]fluoro-L-proline, markers of the collagen synthesis [1091 (Scheme 52). 

Defects in collagen synthesis, structure, or assembly Into fibers are the principal basis for a group of connective tissue disorders called Ehlers-Danlos syndrome (EDS). 

Influence of acute carbon tetrachloride exposure on transcription of liver-specific versus general cellular genes relationship between chronic carbon tetrachloride exposure and collagen synthesis and hepatic fi brosi s. 

The successful use of [ F]FDG in oncology PET imaging has prompted the design of several other radiopharmaceuticals, such as [ F]FLT ([ F]fluorothymi-dine, used as cellular proliferation marker. Scheme 36) [152-154], F-MISO ([ F] fluoromisonidazole, used to assess tissue hypoxia. Scheme 37) [155], c/s-4-[ F] fluoro-L-proline (used as abnormal collagen synthesis marker. Scheme 38) [156] and 0-(2-[ F]fluoroethyl)-L-tyrosine (used as amino acid transport and/or protein synthesis marker. Scheme 39) [157]. All these fluorine-18-labelled molecules have been prepared by aliphatic nucleophilic fluorination followed by a deprotection reaction. 

---