Cellular and Molecular Pathology of Age-Related Macular Degeneration: Potential Role for Proteoglycans

Figure 4

Role of growth factor mediated glycosaminoglycan (GAG) hyperelongation in the trapping of lipids in tissues. PGs have a basal or natural GAG chain length; however under the influence of growth factors the GAG synthesizing mechanism is activated leading to the increased expression of GAG elongation genes and ultimately the secretion of PGs with elongated GAG chains. These chains have increased binding to LDL (see text for details). Lipids trapped in tissues undergo chemical modifications which produce immunogens that initiate an inflammatory cascade and ultimately a chronic inflammatory disease process.