Fig. 3: Amyloidosis induction in λS-DH mice with VL fibrils.

A Protocol of amyloidosis induction with rλS-VL seeds. B Histological characterization of CR birefringence under polarized light (top) and fluorescence (bottom) on frozen tissues. A glomerulus is circled with dotted line. Representative example of a mouse analyzed at 6 months after induction. C Hematoxylin-Eosin and CR staining in a paraffin-embedded heart. Birefringence was visible in the myocardium of the ventricular wall, atrial wall, and around blood vessels throughout the tunica media and adventitia. Representative example of a mouse at 9 months after induction. D Organs from induced mice (λS-DH, red, and controls, blue) were analyzed histologically with CR staining at different time points after the injection. AL-positive mice were determined by the presence of CR fluorescence in the heart, and the penetrance was calculated as the ratio of positive mice to the total number of mice analyzed at each timepoint (indicated below the graph) (E) The amyloidosis score was calculated for the positive mice from (D) (n = 10 at <1 week, n = 12 at 1–2 months (Mo), n = 14 at 3–5 months and n = 6 at >6 months) by the CR fluorescence in the cardiac tissue, corresponding to: score 1 (low), score 2 (mid) and score 3 (high). Score assessment is described in the methods and Fig. S3A. Representation of the single values with mean (gray bar) ± SD. Comparisons were performed by Mann–Whitney two-sided test. Exact P values are indicated. F Electron microscopy of the cardiac tissue showing the amyloid fibrils in the extracellular compartment of a score 3 mouse. G Representative image of fibrotic tissue revealed with a Masson’s Trichrome staining in the hearts of a score 3 mouse (left) and a control (right).