Cytokines and Growth Factors Promote Airway Smooth Muscle Cell Proliferation

Figure 1

The effect of TNF-α (1 ng/mL) and IL-1β (15 ng/mL) on cell proliferation of human bronchial ((a) and (b)) and rabbit tracheal ((c) and (d)) ASMC. Methyl-[³H]thymidine incorporation after 48 h of incubation of ASMC ((a) and (c)) and cell number after 72 h of incubation ((b) and (d)). Where indicated, cells were treated with the MAPK pathway inhibitor, PD89005 (100 μM), or the PI3K pathway inhibitor, LY294002 (20 μM). Data are presented as mean ± SEM, and 𝑁 refers to the number of independent experiments. *𝑃<0.05, **𝑃<0.01, ***𝑃<0.001 compared to control (one-way ANOVA with statistically significant differences between groups being determined by Bonferroni’s posttest) and ^#𝑃<0.05 and ^##𝑃<0.01 compared to the effect of TNF-𝛼 alone (unpaired 𝑡-test with statistically significant differences between groups being determined by Mann-Whitney test).

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(b)

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