Figure 6.

TDP-43 expression induces cell stress and increases cAMP degradation rate. (A) SH-SY5Y cells were transduced with the cell stress biosensor and either no other virus (control), 1 or 10 μl of WT or M337V TDP-43 virus. The green, red and green/red ratio fluorescence was measured after 24 h of expression. Individual data points are plotted and bars represent the mean, error bars represent the standard deviation of N = 3 wells. (B) Average cAMP degradation profiles in SH-SY5Y cells expressing different variants of TDP-43 or control cells. N = 3 wells per sample, control = 2,697 cells, WT = 3,352 cells, M337V = 3,023 cells. (C) Cumulative distribution functions plotted for the distribution of cAMP half-lives (t_1/2) determined from the individual cells analyzed in (B). To determine T_1/2 cAMP, data from each cell were fit to the following equation ΔF/F = α/1+βe^−θt with the same parameters as Figure 4B. (D) PBM index score of cAMP degradation profile clusters in SH-SY5Y cells. Data from control cells or cells expressing WT or M337V versions of TDP-43 were merged for analysis. A maximum at two clusters indicates cAMP degradation profiles can be best segmented into two distinct profiles. (E) Individual cAMP degradation profiles from control cells and cells expressing WT or M337V TDP-43. Each black line represents a single cell; the red line represents the mean response of each profile. Well and cell number are the same as (B). (F) Bar plot of the fraction of cells in each profile for control and TDP-43 variants from the profiles determined in (E). N = 3 wells for each condition. Individual data points are plotted along with the mean bar and error bars representing the standard deviation. *P-value < 0.05, **P-value < 0.01.