Figure 4.

MiR-124 knockdown abolishes the role of nicotine in upregulating the Th1/Th2 ratio in murine and human peripheral blood lymphocytes. Mice were injected daily via the tail vein with 10 mg/kg of LNA-miR-124 or matched scramble control for 3 days. They were then given 3% DSS drinking water together with 0.3 mg/kg of nicotine (subcutaneous injection) for 7 consecutive days (N = 7–10). Human lymphocytes were isolated and treated with IL-2 (80 ng/mL), anti-CD3e (50 ng/mL), and anti-CD28 (50 ng/mL) for 24 h and then transfected with miR-124 LNA or corresponding scramble control (200 ng/mL) for 30 h, followed by with or without nicotine (1 μM) for 6 h. (A,D) Th1/Th2 (IFN-γ/IL-4) ratio was analyzed in each group. N = 3–6 per group. (B,E) Representative flow images showing IFN-γ and IL-4 expression gated on CD4+ T cells. (C) Th1-related cytokines IFN-γ and IL-2 and Th2-related cytokines IL-4, IL-6, and IL-13 in murine colon tissue homogenates were detected by CBA and ELISA. N = 8 per group. Data represent mean ± SEM and were analyzed by one-way ANOVA followed by post-hoc Tukey's test. ^*p < 0.05, ^**p < 0.01. NS, no significant.