Fig 6. Intracellular TTR immunoreactivity in iPS-MLs.

iPS-MLs or control SH-SY5Y cells (1 × 10⁴, 5 × 10⁴, or 1× 10⁵ cells/well) were cultured with native wild-type, wild-type-derived aggregated, native mutated, and mutated-derived aggregated TTR as described in the legend for Fig 5. Cultured iPS-MLs and SH-SY5Y cells were stained with TTR antibody by immunohistochemistry. (A) All slides shown are representative for each group. Arrows indicate intracellular TTR. Scale bars: 50 μm. (B-C) Five visual fields in each stained section were randomly chosen, and the number of TTR⁺ cells counted by two observers. Bar graphs show the frequency of TTR⁺ cells in (B) iPS-MLs and (C) SH-SY5Y cells. The proportion of repeated count TTR⁺ cells were analyzed using the mixed model, with *p < 0.05 and **p < 0.01 indicating a significant difference.