Document Type
Article
Publication Date
9-2014
Abstract
Light-chain amyloidosis (AL) is a degenerative disease characterized by the extracellular aggregation of a destabilized amyloidogenic Ig light chain (LC) secreted from a clonally expanded plasma cell. Current treatments for AL revolve around ablating the cancer plasma cell population using chemotherapy regimens. Unfortunately, this approach is limited to the ∼70% of patients who do not exhibit significant organ proteotoxicity and can tolerate chemotherapy. Thus, identifying new therapeutic strategies to alleviate LC organ proteotoxicity should allow AL patients with significant cardiac and/or renal involvement to subsequently tolerate established chemotherapy treatments. Using a small-molecule screening approach, the unfolded protein response (UPR) was identified as a cellular signaling pathway whose activation selectively attenuates secretion of amyloidogenic LC, while not affecting secretion of a nonamyloidogenic LC. Activation of the UPR-associated transcription factors XBP1s and/or ATF6 in the absence of stress recapitulates the selective decrease in amyloidogenic LC secretion by remodeling the endoplasmic reticulum proteostasis network. Stress-independent activation of XBP1s, or especially ATF6, also attenuates extracellular aggregation of amyloidogenic LC into soluble aggregates. Collectively, our results show that stress-independent activation of these adaptive UPR transcription factors offers a therapeutic strategy to reduce proteotoxicity associated with LC aggregation.
DOI
10.1073/pnas.1406050111
Publisher
National Academy of Sciences
Repository Citation
Cooley, C. B., Ryno, L. M., Plate, L., Morgan, G. J., Hulleman, J. D., Kelly, J. W., & Wiseman, R. L. (2014). Unfolded protein response activation reduces secretion and extracellular aggregation of amyloidogenic immunoglobulin light chain. PNAS, 111(36), 13046-13051. https://doi.org/10.1073/pnas.1406050111
Publication Information
PNAS