Astragaloside IV Ameliorates Airway Inflammation in an Established Murine Model of Asthma by Inhibiting the mTORC1 Signaling Pathway

Figure 6

The effect of AS-IV on the mTOR pathway in lung homogenates. (a), (b), and (c) Western blot analysis for the activation status of mTORC1. P-S6 (Ser235/236) and P-p70S6K (Thr389), the downstream mediators of mTOR complex 1 signaling, were increased in OVA reexposed mice, which were blocked by AS-IV at doses of 20 and 40 mg/kg, as well as rapamycin (Rapa) (4 mg/kg/day) and dexamethasone (Dex) (1 mg/kg/day) treatment ( mice/group). However, increased phosphorylation of 4E-BP1 (Ser65), another substrate of mTORC1, was only inhibited by rapamycin (Rapa) (4 mg/kg/day) and dexamethasone (Dex) (1 mg/kg/day), and AS-IV (10, 20, or 40 mg/kg) had little effects on P-4E-BP1 level. (d) P-Akt, a downstream mediator of mTOR complex 2 signaling, was increased after allergen reexposure compared to mice that had 3 weeks of rest ( mice/group), but it was unaffected by AS-IV, Dex, or Rapa. The data are expressed as the mean ± SEM. and versus OVA reexposure.

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