[Effects of stachyine on apoptosis in an Aß25-35-induced PC12 cell model of Alzheimer's disease].

OBJECTIVE: To investigate the effects of stachydrine (STA) on apoptosis of Aß25-35-induced PC12 cells mimicking Alzheimer's disease and explore the mechanisms. METHODS: The differential genes of STA were analyzed based on GSE85871 data, and the target genes of STA were identified using STITCH database. PC12 cells were treated with Aß25-35 to establish a cell model of Alzheimer's disease, and the changes in cell viability and cell cycle in response to STA treatment were assessed using MTT assay and flow cytometry, respectively. RT-PCR and Western blotting were used to detect the relevant gene or protein expressions in the treated cells. RESULTS: GSE85871 data showed 37 up-regulated genes and 48 down-regulated genes in cells following treatment with STA. Analysis of the data from the STITCH database indicated that RPS8 and EED were the target genes of STA. Treatment of PC12 cells with Aß25-35 significantly lowered the cell viability (P < 0.05) and the expressions of RPS8 and EED at both the mRNA and protein levels (P < 0.05), and obviously inhibited the expression of apoptosis-related proteins Bcl-2 and p53 (P < 0.05). STA treatment of the cells significantly reversed the effect of Aß25-35 and induced cell cycle arrest in G2/M phase, causing also significantly increases in the expression levels of RPS8, EED, Bcl-2 and p53 (P < 0.05). CONCLUSIONS: STA plays an important role in inhibiting the apoptosis of PC12 cells induced by Aß25-35 possibly by regulating RPS8 and EED expression to promote the expressions of Bcl-2 and p53.

[Low-intensity pulsed ultrasound pretreatment inhibits HMGB1 expression and attenuates lung ischemia-reperfusion injury in rats via the cholinergic anti-inflammatory pathway].

OBJECTIVE: To observe the effects of low-intensity pulsed ultrasound (LIPUS) pretreatment on pulmonary expression of high mobility group box-1 (HMGB1) in a rat model of lung ischemia-reperfusion (IR). METHODS: Thirty-two male SpragueDawley rats weighing 250-300 g were randomly divided (n=8) into sham-operated group, lung IR group, LIPUS pretreatment group and pretreatment with α7-nicotinic cholinergic receptor (α7nAChR) antagonist group. In the sham-operated group, the left pulmonary hilum was dissociated without occlusion; in the other 3 groups, the left pulmonary hilum was occluded for 45 min followed by reperfusion for 180 min; LIPUS pretreatment for 30 min and intraperitoneal injection of methyllycaconitine (2 mg/kg), an α7nAChR antagonist, were administered before the operation. The wet/dry weight ratio (W/D) and pulmonary permeability index (LPI) of the lung tissue were measured, and the lung histopathology was observed and scored. The contents of interleukin-1 (IL-1) and IL-6 in the lung tissues were measured using ELISA, and the pulmonary expression of HMGB1 protein was detected using immunofluorescence assay and Western blotting. RESULTS: Compared with those in the sham-operated group, the W/D of the lung tissue, LPI, pathological scores, IL-1 and IL-6 contents in the lung tissue, and pulmonary HMGB1 expression all significantly increased in the other 3 groups (P < 0.05). LIPUS preconditioning significantly lowered the W/D values, LPI, pathological score, IL-1 and IL-6 contents and HMGB1 expression in the lung tissues following lung IR, and these effects were significantly inhibited by administration of methyllycaconitine. CONCLUSIONS: LIPUS preconditioning can reduce lung IR injury possibly by activating α7nAChR-dependent cholinergic anti-inflammatory pathway to reduce lung tissue HMGB1 expression.