Tendons, cells

Michna, H. (1984). Morphometric analysis of loading-induced changes in collagen-fibril populations in young tendons. Cell Tissue Res. 236, 465—470. 

Kardestuncer, T., McCarthy, M.B., Karageorgiou, V., Kaplan, D., and Gronowicz, G. "RGD-tethered silk substrate stimulates the differentiation of human tendon cells". Clin. Orthopaedics Relat. Res. 448, 234-239 (2006). 

Figure 3.22. Structure of tendon. Tendon is composed of rows of tendon cells that are in columns aligned parallel to the axis and parallel bundles of collagen fibers.

Fig. 9. Effect of CsA on the rate of procollagen 1 triple helix formation in suspended chicken embryo tendon cells. The time course of procollagen 1 triple helix formation was monitored in a pulse-chase experiment by separation of protease-resistant al(l) and a2(I) chains by SDS-polyacrylamide gel electrophoresis. The fluorograms (upper panel) show the appearance of protease-resistant and hence triple-helical collagen I in the absence (—) or in the presence (-I-) of 5 fiM CsA. The kinetics are shown in the lower panel (O) no CsA ( ) 5 ixM CsA. Best fits are drawn according to the model of Bruckner and Eikenberry (1984). From Steinmann et al. (1991).

The formation of interchain disulfide linkages in the C-terminal propeptide. The latter cannot be formed until translation is nearly finished. The rate of disulfide bond and triple-helix formation varies greatly from one cell type to another—only minutes in tendon cells that synthesize type I collagen but an hour in cells that synthesize basement membrane collagen. These differences in synthesis time may account for the variations in hydroxylation and glycosylation. Thus, the extent of posttranslational modifications depends not only on levels of enzyme and cofactors but also on the time available. 

The incorporation of ciJ-4-hydroxy-L-proline into procollagen polypeptides, which occurs on incubation with matrix-free chick embryo tendon cells, prevents the polypeptides from folding into a triple-helical formation. Secretion of the non-helical polypeptides is delayed, and contrary to previous observations they are not degraded intracellularly, but instead are secreted as non-helical pro-y chains which contain increased amounts of glycosylated L-hydroxylysine. 

Type I Primary avian tendon cells Lyons and Schwarz, 1984... 

Olsen, B. R., Berg, R. A., Kishida, Y., and Prockop, D. J., 1973, Collagen synthesis Localization of prolyl hydroxylase in tendon cells detected with ferritin-labeled antibodies. Science 182 825-827. 

Egerbacher, M., S. P. Arnoczky, O. Gaballero, M. Lavagnino, and K. L. Gardner. 2008. Loss of homeostatic tension induces apoptosis in tendon cells An in vitro study. Clin Orthop Relat Res 466 1562-68. 

Lavagnino, M., S. P. Arnoczky, E. Kepich, O. Caballero, and R. C. Haut. 2008. A finite element model predicts the mechanotransduction response of tendon cells to cychc tensile loading. Biomech Model Mechanobiol 7 405-16. 

Arnoczky, S. P, T. Tian, M. Lavagnino et al. 2002. Activation of stress-activated protein kinases (SAPK) in tendon cells following cychc strain The effects of strain frequency, strain magnitude, and cytosohc calcium. Journal of Orthopaedic Research 20(5) 947-952. 

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