Isoflurane produces antidepressant effects inducing BDNF-TrkB signaling in CUMS mice.

RATIONALE: The volatile anesthetic isoflurane is suggested to produce a rapid and robust antidepressive effect in preliminary clinical trials. Recently, isoflurane was found to activate the tropomyosin receptor kinase B (TrkB) signaling which is the underlying mechanism of the rapid antidepressant ketamine. OBJECTIVE: Our study investigated the effect of isoflurane anesthesia on chronic unpredictable mild stressed (CUMS) model in mice and verified the role of brain-derived neurotrophic factor (BDNF)/TrkB/ the mammalian target of rapamycin (mTOR) signaling in the antidepressant effect of isoflurane. METHODS: We employed the CUMS model of depression to assess the rapid antidepressant effect of isoflurane by the forced swimming test (FST), the sucrose preference test (SPT), and the novelty suppressed feeding test (NSFT). The protein expression of BDNF and TrkB/protein kinase B (PKB or Akt)/mTOR was determined through Western blot. The dendritic spine density in the hippocampus and medial prefrontal cortex (PFC) was measured by the Golgi staining. RESULTS: A brief burst-suppressing isoflurane anesthesia rapidly reversed the behavioral deficits caused by CUMS procedure, normalized the expression of BDNF and further activated the TrkB signaling pathway in CUMS-induced stressed mice in both prefrontal cortex (PFC) and hippocampus (HC). All of those behavioral and proteomic effects were blocked by K252a, a selective receptor inhibitor of TrkB. Isoflurane significantly promoted the formation of dendritic spines in both medial prefrontal cortex (mPFC), CA1, CA3, and DG of the hippocampus. CONCLUSION: Our study indicates that isoflurane exerts a rapid antidepressant-like effect in CUMS depression animal model, and the activation of BDNF/TrkB signaling pathway plays an indispensable role in the biological and behavioral antidepressant effects of isoflurane. A single exposure to isoflurane could repair synaptic damage caused by chronic stimulation.

Low molecular mass chondroitin sulfate suppresses chronic unpredictable mild stress-induced depression-like behavior in mice.

The present study is aimed at testing the antidepressant--like effects and probable mechanisms of action of low molecular mass chondroitin sulfate (LMMCS) on depression induced by chronic unpredictable mild stress (CUMS) in mice. Four weeks of CUMS exposure resulted in depressive-like behavior, expressed by a significant decrease in the locomotor activity and sucrose consumption and increased immobility time in the forced swim test. Further, there was a significant reduction of 5-HT level in the hippocampus region of depressed mice. Treatment of mice for four weeks with LMMCS ameliorated significantly both the behavioral and biochemical changes induced by CUMS. These novel results suggest that LMMCS produces an antidepressant-like effect in mice subjected to CUMS, which might be related, at least in part, to the increase of 5-HT concentration in the hippocampus.

[Immune response of HBsAg gene-modified dendritic cell-based vaccine in HepG2. 2. 15 hepatocellular carcinoma cells].

OBJECTIVE: To study the cytotoxic T lymphocyte (CTL) response induced by dendritic cells (DC) transduced with recombinant adenovirus vector bearing hepatitis B virus surface antigen (HBsAg) gene in hepatocellular carcinoma HepG2. 2. 15 cells in vitro. METHODS: Full length HBsAg cDNAs were subcloned into pIND vector, followed by being cloned into pShuttle vector. The HBsAg gene fragments resulted from the pShuttle-S digested with PI-Sce and I-Ceu were linked to the linear adeno-X virus DNA. After packaged with HEK293 cells, the adenovirus expression vector was obtained. Then the recombinant adenovirus expression plasmid AdVHBsAg was transfected into human monocyte-derived dendritic cells, to construct AdVHBsAg hepatocarcinoma tumor vaccine. The effectiveness of transfection was detected by Western blot. Surface molecules of AdVHBsAg-DC were detected by FACS. Autologous T cell proliferation stimulated by AdVHBsAg-DC was detected by 3H-TdR assay. Cytotoxic CTL activity induced by AdVHBsAg-DC in vitro was detected by LDH assay. RESULTS: HBsAg gene in the inserted DNA of AdVHBsAg was confirmed by PCR, and predictive fragments proved by restriction enzyme digestion analysis were exhibited. Cell pathological changes appear after 10 days HEK293 cells transfected AdVHBsAg. Western blot analysis showed that HBV surface antigen gene was expressed in transfected DC, indicating that the transfection was effective. AdVHBsAg-DC was able to upregulate CD1a, CD11c, CD80, CD86 and HLA-DR. Autologus T cell proliferation induced by AdVHBsAg-DCs was significantly higher than that in DC control group and LacZ-DC group (P < 0.05). AdVHBsAg-DC activated CTL presented the specific killer ability to the hepatocellular carcinoma cells expressing HBsAg. CONCLUSION: DC transduced with recombinant adenovirus HBsAg can express HBV-related hepatocellular carcinoma antigen (HBsAg), and AdVHBsAg-DC can induce potent immune response against HBsAg-positive hepatocellular carcinoma cells in vitro.

Comparative analysis of DC fused with tumor cells or transfected with tumor total RNA as potential cancer vaccines against hepatocellular carcinoma.

BACKGROUND: DC vaccination with the use of tumor cells provides the potential to generate a polyclonal immune response to multiple known and unknown tumor Ag. Our study comparatively analyzed DC fused with tumor cells or transfected with tumor total RNA as potential cancer vaccines against hepatocellular carcinoma (HCC). METHODS: Immature DC generated from PBMC of patients with HCC were fused with HepG2-GFP (HepG2 cell line transfected stably with plasmid pEGFP-C3) cells or transfected with their total RNA. Matured DC were used to stimulate autologous T cells, and the resultant Ag-specific effector T cells were analyzed by IFN-gamma ELISPOT assay. RESULTS: DC were capable of further differentiation into mature DC after fusion with HepG2-GFP cells or transfection with HepG2-GFP cell total RNA, and were able to elicit specific T-cell responses in vitro. Both methods of Ag loading could result in stimulating CD4+ and CD8+ T cells, but with the indication that fusion loading was more efficient than RNA loading in priming the Th1 response, while RNA loading was more effective in CTL priming. DISCUSSION: Our results indicate that DC fused with tumor cells or transfected with tumor total RNA represent promising strategies for the development of cancer vaccines for treatment of HCC. They may have potential as an adjuvant immunotherapy for patients with HCC.

Induction of alpha-fetoprotein-specific CD4- and CD8-mediated T-cell response using RNA-transfected dendritic cells.

alpha-Fetoprotein (AFP) may be a possible target for a hepatocellular carcinoma (HCC)-specific vaccination. But some studies have demonstrated that dendritic cells (DCs) treated with AFP become dysfunctional. So in this study, we try to transfect AFP mRNA into DCs and observe the ability of DCs to induce AFP-specific CD4(+) and CD8(+) T cells. We hope that AFP can be processed and presented by DCs directly, rather than released to the cultures. So there will be no AFP negative effect on the function of DCs. In the study, immature DCs generated from peripheral blood mononuclear cells (PBMCs) of HLA-A2(+) HCC patients were transfected with AFP mRNA. Then the transfected, matured DCs were used to stimulate autologous T cells. The results showed that the expressions of membrane molecules of DCs after transfection were increased dramatically, and interleukin-12 (IL-12) p70 release in the supernatant was elevated significantly. There was only a minority of AFP release in the supernatants of transfected DCs. CTLs induced by the transfected DCs recognized HLA-matched AFP positive HepG2 cell line specifically and the AFP-specific proliferative T-cell responses could also be induced. These findings indicate that this AFP mRNA transfection strategy could generate fully functional DCs, which could induce specific T cells to recognize AFP(+) HCC cells.

[Cytotoxicity induced by HBsAg gene modified-dendritic cells against hepatocellular carcinoma cell HepG2.2.15].

BACKGROUND & OBJECTIVE: Up to now, there is no efficient immunotherapy for hepatocellular carcinoma (HCC). Dendritic cell (DC) vaccine could be a potential tool for HCC immunotherapy. This study was to evaluate the effect of dendritic cells (DCs) transfected with recombinant plasmid bearing hepatitis B virus surface antigen (HBsAg) gene, and the capability of generating specific cytotoxic T lymphocytes (CTL) response against HepG2.2.15 in vitro, which were induced by genetically modified DCs. METHODS: After cultured for 5 days, the DCs were transfected with pCR3.1-S by liposome. The HBsAg gene expression on pCR3.1-transfected DCs was identified by Western blot analysis, and immunofluorescence methods. The cytotoxicity against HepG2.2.15, which were induced by DCs, was tested by MTT assay. RESULTS: DCs up-regulated the expression of CD1a (55.0%), CD11c (98.6%), CD86 (86.1%), CD80 (66.1%), and HLA-DR (88.9%) after cultured for 5 days. Indirect immunofluorescence, and Western blot analysis showed that HBsAg gene was expressed on transfected DCs. The death rates of HepG2.2.15 cells induced by DCs transfected with pCR3.1-S were (52.3+/-2.8)% (E:T=5:1), (64.6+/-2.4)% (10:1), (78.8+/-2.6) (20:1), (82.1+/-2.4)% (40:1), while the pCR3.1- transfected and non-transfected DCs only induced relatively lower cytotoxicity (P< 0.05, n=4). CONCLUSION: DCs transfected with recombined plasmid expressed HBsAg efficiently, and the genetically modified DCs evoke a higher CTL response in vitro.

Construction and expression of recombined human AFP eukaryotic expression vector.

AIM: To construct a recombined human AFP eukaryotic expression vector for the purpose of gene therapy and target therapy of hepatocellular carcinoma (HCC). METHODS: The full length AFP-cDNA of prokaryotic vector was digested, and subcloned to the multi-clony sites of the eukaryotic vector. The constructed vector was confirmed by enzymes digestion and electrophoresis, and the product expressed was detected by electrochemiluminescence and immunofluorescence methods. RESULTS: The full length AFP-cDNA successfully cloned to the eukaryotic vector through electrophoresis, 0.9723 IU/ml AFP antigen was detected in the supernatant of AFP-CHO by electrochemiluminescence method. Compared with the control groups, the differences were significant (P<0.05). AFP antigen molecule was observed in the plasma of AFP-CHO by immunofluorescence staining. CONCLUSION: The recombined human AFP eukaryotic expression vector can express in CHO cell line. It provides experimental data for gene therapy and target therapy of hepatocellular carcinoma.