Open AccessThis article is
- freely available
Inhibition of Human Transthyretin Aggregation by Non-Steroidal Anti-Inflammatory Compounds: A Structural and Thermodynamic Analysis
Institute of Medical Biochemistry, Structural Biology Program, Federal University of Rio de Janeiro, Rio de Janeiro, RJ 21941-590, Brazil
Polo de Xerém, Federal University of Rio de Janeiro, Rio de Janeiro, RJ 25245-390, Brazil
Institute of Physics of São Carlos, University of São Paulo, Av. Trabalhador Saocarlense, 400, São Carlos, SP 13566-590, Brazil
Institute of Biotechnology and Biomedicine and Department of Biochemistry and Molecular Biology, University of Barcelona, Bellaterra (Barcelona) 08193, Spain
Faculty of Pharmacy, Federal University of Rio de Janeiro, Av. Carlos Chagas Filho 373, CCS, Bss34, Ilha do Fundão, Rio de Janeiro, RJ 21941-902, Brazil
Laboratory for Biotechnology (LaBio-DIPRO), Brazilian National Institute of Metrology, Quality and Technology—INMETRO, Av. N. Sa. das Graças, 50-Xerém, Duque de Caxias, RJ 25250-020, Brazil
* Author to whom correspondence should be addressed.
Received: 8 January 2013; in revised form: 5 February 2013 / Accepted: 7 February 2013 / Published: 6 March 2013
Abstract: Transthyretin (TTR) is a homotetrameric protein that circulates in plasma and cerebral spinal fluid (CSF) whose aggregation into amyloid fibrils has been associated with at least two different amyloid diseases: senile systemic amyloidosis (SSA) and familial amyloid polyneuropathy (FAP). In SSA aggregates are composed of WT-TTR, while in FAP more than 100 already-described variants have been found in deposits. Until now, TTR-related diseases have been untreatable, although a new drug called Tafamidis has been approved only in Europe to specifically treat V30M patients. Thus, new strategies are still necessary to treat FAP caused by other variants of TTR. TTR has two channels in the dimer interface that bind to the hormone thyroxin and that have been used to accommodate anti-amyloidogenic compounds. These compounds stabilize the tetramers, rendering TTR less amyloidogenic. Here, we investigated the effects of three non-steroidal anti-inflammatory compounds—sulindac (SUL), indomethacin (IND) and lumiracoxib (LUM)—as tetramer stabilizers and aggregation inhibitors. WT-TTR and the very aggressive TTR variant L55P were used as models. These compounds were able to stabilize TTR against high hydrostatic pressure (HHP), increasing the ΔGf by several kcal. They were also effective in inhibiting WT-TTR and L55P acid- or HHP-induced aggregation; in particular, LUM and IND were very effective, inhibiting almost 100% of the aggregation of both proteins under certain conditions. The species formed when aggregation was performed in the presence of these compounds were much less toxic to cells in culture. The crystal structures of WT-TTR bound to the three compounds were solved at high resolution, allowing the identification of the relevant protein:drug interactions. We discuss here the ligand-binding features of LUM, IND and SUL to TTR, emphasizing the critical interactions that render the protein more stable and less amyloidogenic.
Keywords: transthyretin; protein aggregation; high hydrostatic pressure; crystallography; inhibitors
Citations to this Article
Cite This Article
MDPI and ACS Style
Sant'Anna, R.O.; Braga, C.A.; Polikarpov, I.; Ventura, S.; Lima, L.M.T.R.; Foguel, D. Inhibition of Human Transthyretin Aggregation by Non-Steroidal Anti-Inflammatory Compounds: A Structural and Thermodynamic Analysis. Int. J. Mol. Sci. 2013, 14, 5284-5311.
Sant'Anna RO, Braga CA, Polikarpov I, Ventura S, Lima LMTR, Foguel D. Inhibition of Human Transthyretin Aggregation by Non-Steroidal Anti-Inflammatory Compounds: A Structural and Thermodynamic Analysis. International Journal of Molecular Sciences. 2013; 14(3):5284-5311.
Sant'Anna, Ricardo O.; Braga, Carolina A.; Polikarpov, Igor; Ventura, Salvador; Lima, Luis M.T.R.; Foguel, Debora. 2013. "Inhibition of Human Transthyretin Aggregation by Non-Steroidal Anti-Inflammatory Compounds: A Structural and Thermodynamic Analysis." Int. J. Mol. Sci. 14, no. 3: 5284-5311.