Figure 3

HL-1 cells incubated with TTR-WT: analysis of the 1500–900 cm⁻¹ spectral range. Left panel: second derivatives of the FTIR absorption spectra of HL-1 cells untreated, incubated for 30 min or for 24 h with TTR-WT in native (top spectra), oligomeric- (middle spectra) and fibrillar-like (bottom spectra) conformation. The spectra are shown after normalization at Amide I band area, in two spectral ranges: 1500–1350 cm⁻¹, mainly due to lipid absorption (panel a), and 1200–900 cm⁻¹ (panel b). At the bottom, the pseudoloadings are shown as coloured bands: wider, red-coloured bands indicate important wavenumbers, while thinner, blue-coloured bands indicate unimportant wavenumbers (see bottom-right colour bar). Representative wavenumbers are indicated on the plot. Right panels: differences of the average (across spectra) linear mixed model response variable (η, see Methods for details) between TTR-WT treated (pH7, OL, FB at 30 min and 24 h) and control (NT) cells. Error bars show the 95% confidence interval. Stars above the vertical bar indicate the Dunnet’s adjusted two-sided P-values from two-sample Student t-test. P-value: ** < 0.01.