Gelsolin Amyloidosis: aggregation propensities of wild and mutant peptides and their inhibition

Abstract

AbstractBackgroundGelsolin is an actin‐binding protein responsible for the remodeling of the actin cytoskeleton. Gelsolin Amyloidosis, the formation of misassembled protein into insoluble amyloid fibril aggregates, is the result of point mutations that promote aberrant proteolytic cleavage. Amyloidosis can be instigated and spread by existing amyloid fibrils through the process of seeding, where existing fibrils promote the formation of new fibrils. Gelsolin fragments are prone to aggregation and systematic deposition into organs including peripheral/cranial nerves, skin, eyes, and kidneys. The D187Y mutation has been identified to promote cleavage of Gelsolin, although studies have demonstrated the mutant’s elusive aggregation propensity.MethodMutant Gelsolin peptide aggregation was monitored and characterized in vitro using various spectroscopic methods, Thioflavin T (ThT), turbidity, and Dynamic Light Scattering (DLS). Transmission electron microscopy (TEM) allowed for the identification and visualization of β‐sheet formation within aggregatesResultWe reported that CFILDL‐containing peptides were prone to aggregation, which may be inhibited by using small molecules. Of note is the unique behaviour of peptide mutants with respect to their aggregation propensities pointing to their biological relevance. Preliminary results suggest that seeding may induce peptide aggregationConclusionSince other neurodegenerative proteinopathies (Alzheimer’s & Parkinson’s) exhibit similar prion‐like mechanisms of seeding that initiate aggregation, understanding the fundamentals of seeding may expose potential therapeutic targets for preventing the progression of amyloidosis.References 1) Ahmad, M., Esposto, J., Golec, C., Wu, C., & Martic‐Milne, S. (2021). Aggregation of gelsolin wild‐type and G167K/R, N184K, and D187N/Y mutant peptides and inhibition. Molecular and Cellular Biochemistry, 476, 2393–2408. https://doi.org/10.1007/s11010‐021‐04085‐62) Walker, L. C., Diamond, M. I., Duff, K. E., & Hyman, B. T. (2013). Mechanisms of protein seeding in neurodegenerative diseases. JAMA Neurology, 70, 304‐310. https://doi.org/10.1001/jamaneurol.2013.14533) Solomon, J. P., Page, L. J., Balch, W. E., & Kelly, J. W. (2012). Gelsolin amyloidosis: genetics, biochemistry, pathology and possible strategies for therapeutic intervention. Critical Reviews in Biochemistry and Molecular Biology, 47, 282–296. https://doi.org/10.3109/10409238.2012.6614014) Ihne, S., Morbach, C., Sommer, C., Geier, A., Knop, S., & Störk, S. (2020). Amyloidosis‐the diagnosis and treatment of an underdiagnosed disease. Deutsches Ärzteblatt International, 117, 159–166. https://doi.org/10.3238/arztebl.2020.0159