Pre-extinction activation of hippocampal AMPK prevents fear renewal in mice.

As a type of fear relapse, fear renewal compromises the efficacy of fear extinction, which serves as the laboratory analog of exposure therapy (a therapeutic strategy for anxiety disorders). Interventions aiming to prevent fear renewal would thus benefit exposure therapy. To date, it remains unknown whether central adenosine monophosphate (AMP)-activated protein kinase (AMPK) activation could produce inhibitory effects on fear renewal. Here, using pharmacological approach and virus-mediated gene overexpression technique, we demonstrated that activation of AMPK in dorsal hippocampus shortly before fear extinction training completely abolished subsequent fear renewal in male mice without affecting other types of fear relapse, including spontaneous recovery of fear and fear reinstatement. Furthermore, we also found that metformin, a first-line antidiabetic drug, was capable of preventing fear renewal in male mice by stimulating AMPK in dorsal hippocampus. Collectively, our study provides insight into the role of hippocampal AMPK in regulation of fear renewal and indicates that increasing activity of hippocampal AMPK can prevent fear renewal, thus enhancing the potency of exposure therapy.

[Effects of Xiangsha Liujunzi decoction on TLR signal pathway in gastric mucosa tissues of rats with Helicobacter pylori-induced chronic atrophic gastritis].

To explore the effects and mechanism of Xiangsha Liujunzi decoction on TLR signal pathway in gastric mucosa tissues of rats with Helicobacter pylori-related gastritis, sixty SD rats were randomly divided into control group, model group, high concentration of Xiangsha Liujunzi decoction group, moderate concentration of Xiangsha Liujunzi decoction group, low concentrations of Xiangsha Liujunzi decoction group and SB203580-treated group, with 10 rats in each group. SD rats of Hp-associated chronic atrophic gastritis models were established by intragastric gavage of Helicobacter pylori (HP) suspension. Changes in the gastric mucosa of rats were assessed by histopathology. ELISA was applied to detect the expressions of TNF-α and IL-6 in the serum, and the activity of iNOS in gastric mucosa. The content of NO in the gastric mucosa was tested by nitrate reductive enzymatic. The expressions of TLR2, TLR4, P38MAPK, NF-κB were detected by QPCR and Western-blot. The results indicated that the clinical symptoms of rats and pathological changes of gastric mucosa were improved in Xiangsha Liujunzi decoction group. Compared with normal control group, the protein expressions of TLR2, TLR4, p-P38MAPK and NF-κB in gastric mucosa of model group rats increased (P<0.01) with the levels of TNF-α and IL-6 in the serum, and the activity of iNOS and the content of NO in gastric mucosa increased. Compared with model group, the expressions decreased in Xiangsha Liujunzi decoction group, especially in the high concentration of Xiangsha Liujunzi decoction group(P<0.01), with gradually increased rate of HP eradication and decreased pathological grades of chronic atrophic gastritis. The serum level of TNF-α and IL-6 decreased from (24.313±2.261) µg•L ⁻¹ to (15.195±1.235) µg•L-1(P<0.01) and from (77.416±8.095) µg•L ⁻¹ to (33.150±2.532) µg•L ⁻¹ (P<0.01), and the activity of iNOS and the content of NO in gastric mucosa decreased from (1.530±0.206) U•mg ⁻¹ to (0.802±0.091) U•mg ⁻¹ (P<0.01) and from (0.907±0.032) mmol•g ⁻¹ to (0.335±0.026) mmol•g ⁻¹ (P<0.01) after the treatment of high concentration of Xiangsha Liujunzi decoction. All the effects increased with the increasing dosage of Xiangsha Liujunzi decoction from 0.324 g•mg ⁻¹ to 1.296 g•mg ⁻¹. The protein expressions of NF-κB decreased in the gastric mucosa after treated with P38MAPK specific inhibitor-SB203580. In the rats model, HP infection results in chronic atrophic gastritis through the activation of TLR2, TLR4/MAPK/NF-κB/iNOS/NO signal pathway. Xiangsha Liujunzi decoction can eradicate H. pylori and alleviate chronic atrophic gastric mucosal inflammation. The treatment is effective and safe to cure HP-induced chronic atrophic gastritis.

The granulocyte macrophage-colony stimulating factor surface modified MB49 bladder cancer stem cells vaccine against metastatic bladder cancer.

The MB49 bladder cancer cell vaccine was effective against bladder cancer in the mice model in previous studies. However, part of the tumors regrew as the vaccine could not eliminate the cancer stem cells (CSCs). MB49 bladder cancer stem cells (MCSCs) were isolated by a combination of the limited dilution method and the serum free culture medium method. MCSCs possessed higher expression of CD133, CD44, OCT4, NANOG, and ABCG2, the ability of differentiation, higher proliferative abilities, lower susceptibility to chemotherapy, greater migration in vitro, and stronger tumorigenic abilities in vivo. Then streptavidin-mouse granulocyte macrophage-colony stimulating factor (SA-mGM-CSF) MCSCs vaccine was prepared. SA-mGM-CSF MCSCs vaccine extended the survival of the mice and inhibited the growth of tumor in protective, therapeutic, memorial and specific immune response experiments. The level of immunoglobulin G and the ratio of dendritic cells and CD4(+) and CD8(+) T cells were highest in the experimental group when compared to those in other four control groups, as well as for the cytotoxicity assay. We demonstrated that SA-mGM-CSF MCSCs vaccine induces an antitumor immune response to metastatic bladder cancer.

[Expression of Gluc-Fluc dual luciferase plasmid after transfection into MB49 bladder cells].

OBJECTIVE: To investigate the expression characteristics of Gluc-Fluc dual luciferase plasmid after its transfection into MB49 bladder cells. METHODS: pAAV2neoCAG-Gluc-2A-Fluc and pAAV2neo-Gluc plasmids were separately transfected into MB49 cells via LipofectamineTM2000. The Gluc activity in the cell culture supernatant and the Fluc activity in the cells were detected by luminometer and Lumina Imaging system. RESULTS: The luminometer result showed that the activity of Gluc in the supernatant increased gradually in a cell number- and time-dependent manner, while Fluc activity in the cells increased with the cell number but not with time. The Lumina Imaging system showed that Gluc-Fluc was successfully expressed in MB49 bladder cells and cell lines with stable Gluc-Fluc expression were obtained after G418 selection. CONCLUSION: Gluc in the dual luciferase plasmid retains its expression characteristics. Due to the advantages of Fluc in localization in living imaging and the easy quantitative detection of Gluc, the dual luciferase plasmid, after transfection in MB49 bladder cells, allows reliable and dynamic detection of tumor growth in animal models.

[Construction of a dual-luciferase co-expression vector and its characteristics in vitro and in vivo].

A novel dual luciferase expression vector was designed and its expression characteristics were studied in vitro and in vivo. Firstly, the Gluc and Fluc genes were connected via the TaV 2A sequence by overlaping PCR, and inserted into the expression vector pAAV2neoCAG, obtaining the recombinant plasmid pAAV2neoCAG-Gluc-2A-Fluc. Then pAAV2neoCAG-Gluc-2A-Fluc was transfected into BHK21 cells and the activity of Gluc and Fluc in the supernatant and cell lysates were assayed respectively. Results showed that both Gluc and Fluc were expressed successfully. The Gluc was mainly detected in the culture media while the Fluc was mostly within cells. The activity of Gluc in the supernatant increased gradually with time while the Fluc activity in cells almost kept stable. To investigate the expression of pAAV2neoCAG-Gluc-2A-Fluc in vivo, the plasmid was hydrodynamically injected into BALB/c mice through tail vein. The Gluc activity was assayed in a small volume of blood taken by tail vein at different time points. Results showed that Gluc was expressed stably at least 7 days. Live bioluminescence imaging technology was used to compare the expression characteristics of Gluc and Fluc. Whole body imaging was seen when coelenterazine, a specific substrate for Gluc, was injected, and the imaging signals decreased rapidly within 10 minutes. Liver imaging was showed when Flue specific substrate named D-Luciferin was injected, and the imaging remained stable at least for half an hour. The dual luciferase expression vector pAAV2neoCAG-Gluc-2A-Fluc combines the advantages of the secreted report gene Gluc and the non-secreted report gene Fluc, and will provide a new tool for cell labeling and tracing.