ABSTRACT
Proteoglycans are associated with amyloid fibrils in patients with systemic amyloidosis. There is extensive data implicating heparan sulfate proteoglycans (HSPGs) in the genesis of amyloid. This chapter aim is to evaluate the response of primary cardiac fibroblasts to exogenous amyloidogenic light chains (LCs) and to correlate the localization of LCs with expression and localization of heparan sulfate proteoglycans. The response of cells to 11 urinary IgG LCs of kappa1, lambda 6 and 3 subtypes was evaluated and compared to a urinary LC from a patient with multiple myeloma and no amyloid. As the length of exposure to LC increased there was a transition from a punctate pattern to a filamentous appearance. The extensiveness of the filaments within the cells varied with the specific LCs and did not co-localize with F-actin. Cells displayed a transition from a fibroblast to myofibroblast morphology with extensive actin filaments. This change has been noted in other fibroblast cells in response to injury.
