Making biological membrane resistant to the toxicity of misfolded protein oligomers: a lesson from trodusquemine
Authors: Errico S., Lucchesi G., Odino D., Muscat S., Capitini C., Bugelli C., Canale C., Ferrando R., Grasso G., Barbut D., Calamai M., Danani A., Zasloff M., Relini A., Caminati G., Vendruscolo M., Chiti F.
Autors Affiliation: Univ Florence, Dept Expt & Clin Biomed Sci, Biochem Sect, Florence, Italy; Univ Cambridge, Dept Chem, Ctr Misfolding Dis, Cambridge, England; Univ Florence, Dept Chem Ugo Schiff, Sesto Fiorentino, Italy; Univ Florence, CSGI, Sesto Fiorentino, Italy; Univ Genoa, Dept Phys, Genoa, Italy; Univ Italian Switzerland USI, Dalle Molle Inst Artificial Intelligence IDSIA, Univ Appl Sci & Arts Southern Switzerland SUPSI, Lugano, Switzerland; European Lab Nonlinear Spect LENS, Sesto Fiorentino, Italy; Univ Florence, Dept Phys & Astron, Florence, Italy; Enterin Inc, 2005 Market St, Philadelphia, PA 19103 USA; Natl Res Council Italy CNR, Natl Inst Opt, Florence, Italy; Georgetown Univ, Sch Med, MedStar Georgetown Transplant Inst, Washington, DC USA
Abstract: Trodusquemine is an aminosterol known to prevent the binding of misfolded protein oligomers to cell membranes and to reduce their toxicity in a wide range of neurodegenerative diseases. Its precise mechanism of action, however, remains unclear. To investigate this mechanism, we performed confocal microscopy, fluorescence resonance energy transfer (FRET) and nuclear magnetic resonance (NMR) measurements, which revealed a strong binding of trodusquemine to large unilamellar vesicles (LUVs) and neuroblastoma cell membranes. Then, by combining quartz crystal microbalance (QCM), fluorescence quenching and anisotropy, and molecular dynamics (MD) simulations, we found that trodusquemine localises within, and penetrates, the polar region of lipid bilayer. This binding behaviour causes a decrease of the negative charge of the bilayer, as observed through zeta potential measurements, an increment in the mechanical resistance of the bilayer, as revealed by measurements of the breakthrough force applied with AFM and zeta potential measurements at high temperature, and a rearrangement of the spatial distances between ganglioside and cholesterol molecules in the LUVs, as determined by FRET measurements. These physicochemical changes are all known to impair the interaction of misfolded oligomers with cell membranes, protecting them from their toxicity. Taken together, our results illustrate how the incorporation in cell membranes of sterol molecules modified by the addition of polyamine tails leads to the modulation of physicochemical properties of the cell membranes themselves, making them more resistant to protein aggregates associated with neurodegeneration. More generally, they suggest that therapeutic strategies can be developed to reinforce cell membranes against protein misfolded assemblies.
Volume: 12 (44) Pages from: 22596 to: 22614
KeyWords: SUPPORTED LIPID-BILAYERS; ATOMIC-FORCE MICROSCOPY; PLASMA-MEMBRANE; FLUORESCENCE PROPERTIES; MOLECULAR-DYNAMICS; GM1 GANGLIOSIDE; CHOLESTEROL; RAFTS; MODEL; TRANSITIONSDOI: 10.1039/d0nr05285jConnecting to view paper tab on IsiWeb: Click here