Fig 2: The expression of PI3K, p-AKT, cleaved caspase-9, cleaved caspase-3, Bax and Bcl-2 protein in PC12 cells was induced by ischemia-reperfusion for 24 h after MTC treatment. (a) Western blot analysis showed that the levels of PI3K activated by MTC post-treatment; (b) Western blot analysis showed that the levels of p-AKT activated by MTC post-treatment; (c) Western blot analysis showed that the levels of cleaved caspase-9 was inhibited by MTC post-treatment; (d) Western blot analysis showed that the levels of cleaved caspase-3 was inhibited by MTC post-treatment; (e) Western blot analysis showed that the levels of bax was inhibited by MTC post-treatment, # p < 0.05; (f) Western blot analysis showed that the levels of Bcl-2 was activated by MTC post-treatment. Compared with control group, ## p < 0.01; Compared with MI group, ** p < 0.01, * p < 0.05; (g) The levels of PI3K and p-ATK showed that the treatment after MTC (1 µM) was inhibited by pretreatment with LY294002 (20 µM); Compared with control group, ## p < 0.01; Compared with MTC + LY294002 group, * p < 0.05.

Fig 3: DCP acts on Ras/Raf/MEK/ERK and Ras/PI3K/Akt/mTOR compensatory signaling pathwaysHLE cells were pretreated with PD98059 (80 µM) for 1 h and then treated with DCP (80 ng/ml) and/or Sorafenib (20 µM) for 3 h. Western blot analysis was performed to evaluate the expression of pERK, p-MEK1/2Ser217/221, p-c-RafSer259, p-AktSer473, p-mTORSer2481, PI3K p110a, Ras, Bcl-2, Mcl-1, and Bax. Gels were run under the same experimental conditions. The cropping lines in the figure represent full-length gels. A. 80 µM PD98059 for 1 h completely inhibited the expression of p-ERK in HLE cells. B. The changes in the Ras/Raf/MEK/ERK cascade in HLE cells exposed to DCP when ERK was inhibited. Bars indicate means ± S.D. (n = 3). *p < 0.05, **p < 0.01 vs. the vehicle control. C. The changes in the Ras/PI3K/Akt/mTOR cascade in HLE cells exposed to DCP and Sorafenib after ERK was inhibited. The expressions of p-MEK1/2 and p-c-Raf were decreased and Ras was activated (C, right panel). Bars indicate means ± S.D. (n = 3). *p < 0.05, **p < 0.01 vs. the cells exposed to DCP.

Fig 4: Effect of let-7b inhibitor on PI3K/AKT/mTOR signaling pathway. (a) Typical Western blot diagram of the expression of each molecule. (b) Statistical graphs of beclin-1 expression in each group. (c) Statistical graphs of LC3II/LC3I expression in each group. (d) Statistical graphs of cleavage caspase 3 expression in each group. (e) Statistical graphs of PI3K expression in each group. (f) Statistical graphs of p-AKT expression in each group. (g) Statistical graphs of p-MTOR expression in each group. n = 6, * *p < 0.01, and * * *p < 0.001 versus control group; ###p < 0.001 versus Aß1-40 group, and p < 0.01 versus Aß1-40 + let-7b mimic group.

Fig 5: Effect of let-7b on autophagy and apoptosis of SK-N-SH cells treated with Aß1-40s. (a) Typical Western blot diagram of the expression of each molecule. (b) Statistical graphs of beclin-1 expression in each group. (c) Statistical graphs of LC3II/LC3I expression in each group. (d) Statistical graphs of cleavage caspase 3 expression in each group. (e) Statistical graphs of PI3K expression in each group. (f) Statistical graphs of p-AKT expression in each group. (g) Statistical graphs of p-MTOR expression in each group. n = 6, * *p < 0.01, and * * *p < 0.001 versus control group; ###p < 0.001 versus Aß1-40 group, and p< 0.01 versus Aß1-40 + let-7b mimic group.