Fig. 4

Metabolic and proliferative behaviour of cells derived from cholesteatoma tissue stimulated with LPS. a A MTT assay of ME-CSCs and ME-CFs with or without stimulation with LPS. Some ME-CSCs showed a significantly higher metabolic activity. A broader investigation (n = 3) could not verify the significance of this enhanced metabolism. In ME-CFs the metabolic activity was already enhanced after three days of cultivation. b Proliferation assay of ME-CSCs and ME-CFs derived from the same donor. The ME-CSCs showed only a small and insignificant enhancement in proliferation while the ME-CF exhibited a drastic change in mitotic activity upon LPS stimulation. c Proliferation assay executed with the same ME-CFs as shown in (b) with and without LPS stimulation and with the LPS quenched by the antagonists LPS-RS (left). A clear reduction in doubling time is detectable for the LPS-treated and even a bit for the control population. Biological triplicates of this experiment (right) demonstrated, that this effect is statistically significant (depicted: doubling time and standard deviation derived from exponential curve fit; one tailed paired (for bar diagrams) and one tailed non paired t-test (for data points in the xy-graphs)with 95% confidence interval upon passed Shapiro–Wilk normality test, ns ≥ 0.05, *≤ 0.05, **≤ 0.01,****≤ 0.0001)