Establishment and evaluation of a monkey acute cerebral ischemia model

OBJECTIVES: Cerebral ischemia seriously threatens human health and is characterized by high rates of incidence, disability and death. Developing an ideal animal model of cerebral ischemia that reflects the human clinical features is critical for pathological studies and clinical research. The goal of this study is to establish a local cerebral ischemia model in rhesus macaque, thereby providing an optimal animal model to study cerebral ischemia. METHODS: Eight healthy rhesus monkeys were selected for this study. CT scans were performed before the operation to exclude cerebral vascular and intracranial lesions. Under guidance and monitoring with digital subtraction angiography (DSA), a microcatheter was inserted into the M1 segment of the middle cerebral artery (MCA) via the femoral artery. Then, autologous white thrombi were introduced to block blood flow. Immediately following embolization, multisequence MRI was used to monitor cerebrovascular and brain parenchymal conditions. Twenty-four hours after embolization, 2 monkeys were sacrificed and subjected to perfusion, fixation and pathological examination. RESULTS: The cerebral ischemia model was established in 7 rhesus monkeys; one animal died during intubation. DSA and magnetic resonance angiography (MRA) indicated the presence of an arterial occlusion. MRI showed acute local cerebral ischemia. HE staining revealed infarct lesions formed in the brain tissues, and thrombi were present in the cerebral artery. CONCLUSION: We established a rhesus macaque model of local cerebral ischemia by autologous thrombus placement. This model has important implications for basic and clinical research on cerebral ischemia. MRI and DSA can evaluate the models to ensure accuracy and effectiveness.

Ursolic acid regulates apoptosis and autophagy of gastric cancer cell line MGC803 and its mechanism / 中国肿瘤生物治疗杂志

@# Objective: To observe the effect of ursolic acid (UA) on autophagy and apoptosis of gastric cancer cell line MGC-803, and to explore the mechanism of UA-induced autophagy of MGC-803 cells based on PI3K/AKT/mTOR signaling pathway. Methods: Human gastric cancer cell line MGC-803 was cultured in vitro and divided into blank control group, UAintervention group and UA+3-MA group. The cell apoptosis in each group was detected by flow cytometry. Cell autophagy was detected by double fluorescence mRFPeGFP-LC3 plasmid transfection method. The mRNA expression levels of LC3B, BAX and Bcl-2 were detected by qPCR. The protein expression levels of PI3K type I, p-AKT, p-mTOR, ULK1, LC3B, BAX and Bcl-2 were detected by WB. Results: Flow cytometry showed that the cell apoptotic rate of UA intervention group was significantly higher than that of blank control group (P<0.05). Compared with UAintervention group, the apoptotic rate in UA+ 3-MAgroup was significantly reduced (P<0.05). The double fluorescence mRFP-eGFP-LC3 plasmid transfection method showed that the green and red fluorescent bright spots in UA intervention group increased significantly compared with the blank control group (P<0.05), and the green and red fluorescent bright spots in UA+3-MA group were significantly reduced compared with UA intervention group (P<0.05). Real-time quantitative PCR and WB method showed that compared with the blank control group, the mRNAand protein expressions of BAX and LC3B, and ULK1 protein were significantly increased in UA intervention group, while the mRNA and protein expressions of Bcl-2, and the protein expressions of PI3K, p-AKT and p-mTOR were significantly decreased in UA intervention group (all P<0.05); Compared with UA intervention group, mRNA and protein expressions of BAX and LC3B were significantly down-regulated and the mRNAand protein expressions of Bcl-2 were significantly up-regulated in UA+3-MA group (all P<0.05), while protein levels of PI3K, p-AKT, p-mTOR and ULK1 were not significantly changed in UA+3-MA group (P>0.05). Conclusion: UA can promote apoptosis of MGC-803 cells via inducing autophagy, which may be related to UA's involvement in regulating the expressions of PI3K/AKT/mTOR signaling pathway-related proteins.

Effects of costunolide on the biological behaviours of cholangiocarcinoma RBE cells and its mechanism / 中国肿瘤生物治疗杂志

@# Objective: To investigate the effects of costunolide (Cos) on the proliferation, apoptosis, migration andinvasion of cholangiocarcinoma RBE cells, and explore its potential mechanism. Methods: The CCK-8, flow cytometry,Annexin V-FITC/PI double staining, Transwell assays were used to examine the influence of Cos on proliferation, cell cycle, apoptosis, migration and invasion of RBE cells after treated with gradient concentrations of Cos. The expressions of M M P 2 and M M P 9 were detected by qRT-PCR, and the expression of PI3K/AKT-associated signal proteins was detected by Western blotting. Results: Cosdose-dependently inhibited proliferation activity of RBE cells( P <0.05 or P <0.01), arrested cell cycle at S and G2/M phases and induced RBE cell apoptosis( P <0.01). Transwell and qRT-PCR results demonstrated that Cos impeded RBE cell migration, invasion, and reduced the transcription of M M P 2 and M M P 9 . Cos inhibited the expressionofp-AKT, Bcl-2, MMP2 and MMP9, the level of Bax. Conclusion: Cos restrained the proliferation, migration and invasion of RBE cells by suppressing PI3K/AKTpathway.