Figure 2: The mast cell clock regulates OCT3 expression, thereby temporally modulating plasma histamine levels.
From: Regulation of plasma histamine levels by the mast cell clock and its modulation by stress
(A) Kinetics of OCT3 and Per2 mRNA expression levels in wild-type (WT) or ClockΔ19/Δ19 BMMCs. (n = 4) (One-way ANOVA). (B) Kinetics of OCT3 protein expression levels in wild-type or ClockΔ19/Δ19 BMMCs. (n = 10–12) (One-way ANOVA). (C) OCT3 protein expression levels in peritoneal mast cells isolated from wild-type or ClockΔ19/Δ19 mice at ZT4 or ZT16. (n = 5) (One-way ANOVA with Bonferroni’s test). (D) Detection of CLOCK binding to the promoter region of mouse OCT3 (left panel) or E2 or E5 enhancer of mouse Per2 (right panel) in wild-type BMMCs cultured for 6, 12 18, or 24 hours after a media change for synchronization. (n = 4) (Unpaired student’s t-test). (E) OCT3 and Syk mRNA expression levels in wild-type BMMCs 24 and 36 hours after transfection with Clock siRNA. (n = 4) (Unpaired student’s t-test). (F) Histamine concentration in culture supernatants of wild-type BMMCs 24 hours after treatment with vehicle or D22. (n = 4) (One-way ANOVA with Bonferroni’s test). (G) OCT3 protein expression levels in wild-type BMMCs 24 and 36 hours after transfection with OCT3 or control siRNA. (n = 4) (Unpaired student’s t-test). (H) Histamine concentration in culture supernatants of wild-type BMMCs 24 hours after OCT3 or control siRNA transfection. (n = 6) (Unpaired student’s t-test). (I) Plasma histamine levels in mice treated with D22. Wild-type mice were i.p. injected with vehicle or D22 at ZT4, and then plasma histamine concentrations were measured by ELISA 24 hours (ZT4) or 36 hours (ZT16) after the treatment. (n = 5–6) (One-way ANOVA with Bonferroni’s test) Similar results (A–I) were obtained at least from 2 independent experiments. The values represent means ± SD, *p < 0.05, **p < 0.01.
