State-dependent effects of atypical benzodiazepine-receptor agonists

The state-dependent effect of the BZ-receptor agonist diazepam (1.25–10 mg/kg), the partial agonist FG 8205 (0.5–4.0 mg/kg) and the BZ₁-receptor agonist zolpidem (0.25–2 mg/kg) were investigated in rats. During daily sessions, animals were trained to acquire FR10 lever pressing for food reinforcement whilst under the influence of the agonists, using an operant technique. Forty-eight hours after the final training session under drug, their performance of the FR10 was evaluated during a test session, carried out following vehicle administration only. Neither diazepam, nor FG 8205 impaired acquisition of the task. In the group treated with 2 mg/kg zolpidem, six out of eight rats failed to learn within 20 sessions, but the smaller doses were without effect on acquisition. When drug treatment was withdrawn, there was evidence that all three of the agonists tested produced state-dependency. This was apparent in the form of longer latencies to obtain reinforcement and decreased lever pressing rates. The significance of these findings are discussed in the context of the relationship between the state-dependent effects of BZ-receptor agonists and their other properties, and the receptor subtypes which might underly these effects.     

蜗神经核向下丘的投射（FG逆行追踪法研究）

用荧光金（Ｆｌｕｏｒｏｇｏｌｄ，ＦＧ）逆行追踪技术对大鼠蜗神经核（ＣＮ）向下丘（ＩＣ）的投射进行了研究。将ＦＧ注入一侧下丘中央核（ＩＣＣ）的大部分区域后，标记细胞主要出现在对侧ＣＮ的所有亚核；将ＦＧ注入到一侧ＩＣＣ的腹侧都，标记细胞出现在对侧ＣＮ的背例部；将ＦＧ注入一侧ＩＣＣ的背侧部，标记细胞出现在对侧ＣＮ的腹倒部；将ＦＧ注入一侧下丘外核（ＩＣＸ），主要在对侧蜗神经背倒核（ＤＣＮ）发现标记细胞；将ＰＧ注入一侧下丘背核（ＩＣＤ），双例ＣＮ均未见到标记细胞。在所有标记细胞中，以多极细胞和梭形细胞为多。     

Chronic cocaine self-administration attenuates the anxiogenic-like and stress potentiating effects of the benzodiazepine inverse agonist, FG 7142

Stress is a well-known risk factor in relapse to drug abuse. Several forms of stress in animals have been used with varied degrees of success to elicit reinstatement of drug-seeking after chronic drug self-administration. Here, we tested the ability of the benzodiazepine (BZ) inverse agonist, FG 7142, to elicit anxiety-like behavior and potentiate stress responses in rats as measured by standard behavioral and hormonal indices and for its ability to affect reinstatement of cocaine-seeking in rats with a prior history of cocaine self-administration. FG 7142 elicited anxiety-like behavior on the elevated plus maze (EPM) in cocaine-naïve rats, and cocaine-naïve rats injected with FG 7142 exhibited increased plasma corticosterone levels following EPM exposure. However, in animals with a history of cocaine self-administration, FG 7142 failed to affect elevated plus maze performance and did not affect plasma corticosterone response to the EPM. Furthermore, FG 7142 failed to reinstate cocaine-seeking, nor did it alter conditioned cue-induced reinstatement. These data indicate that the anxiety-related and stress potentiating qualities of BZ inverse agonism are attenuated in cocaine-experienced animals and do not lead to reinstatement of cocaine-seeking.     

Self-assembled FeS-based cascade bioreactor with enhanced tumor penetration and synergistic treatments to trigger robust cancer immunotherapy

Major challenges for cancer treatment are how to effectively eliminate primary tumor and sufficiently induce immunogenic cell death (ICD) to provoke a robust immune response for metastasis control. Here, a self-assembled cascade bioreactor was developed to improve cancer treatment with enhanced tumor penetration and synergistic therapy of starvation, chemodynamic (CDT) and photothermal therapy. Ultrasmall FeS-GOx nanodots were synthesized with glucose oxidase (GOx) as template and induced by paclitaxel (PTX) to form self-assembling FeS-GOx@PTX (FGP) via hydrophobic interaction. After accumulated at tumor sites, FGP disassembles to smaller FeS-GOx for enhanced deep tumor penetration. GOx maintains high enzymatic activity to catalyze glucose with assistant of oxygen to generate hydrogen peroxide (H₂O₂) as starvation therapy. Fenton reaction involving the regenerated H₂O₂ in turn produced more hydroxyl radicals for enhanced CDT. Following near-infrared laser at 808 nm, FGPs displayed pronounced tumor inhibition in vitro and in vivo by the combination therapy. The consequent increased exposure to calreticulin amplified ICD and promoted dendritic cells maturation. In combination with anti-CTLA4 checkpoint blockade, FGP can absolutely eliminate primary tumor and avidly inhibit distant tumors due to the enhanced intratumoral infiltration of cytotoxic T lymphocytes. Our work presents a promising strategy for primary tumor and metastasis inhibition.     

Anti-atherosclerotic action of Ger-Gen-Chyn-Lian-Tang and AMPK-dependent lipid lowering effect in hepatocytes

Ethnopharmacological relevance

The Ger-Gen-Chyn-Lian-Tang (GGCLT), an officially standardized mixture of Chinese herbal medicines, consists of Puerariae Radix, Scutellariae Radix, Coptidis Rhizoma and Glycyrrhizae Radix in a ratio of 8:3:3:2. In this study, we evaluated the benefits of GGCLT in atherosclerotic progression.

Methods

The major constituents of GGCLT were analyzed by HPLC. ApoE^−/− mice taken 0.15% cholesterol diet were orally given vehicle or GGCLT (2 g/kg/day) for 12 weeks. Serum levels of lipid and glucose were analyzed, and atherosclerosis was examined by histological analyses. Cultures of vascular smooth muscle cells, hepatocytes and bone marrow-derived macrophages were used to investigate the action mechanisms of GGCLT.

Results

Our quantitation results indicated that GGCLT contains puerarin, daidzin, daidzein, baicalin, baicalein, wogonin, palmatine, coptisine, berberine and glycyrrhizin. GGCLT decreased serum levels of total cholesterol and LDL, but not TG and HDL in ApoE^−/− mice. In parallel, GGCLT treatment reduced atherosclerotic lesions and collagen expression in atheroma plaques. In vascular smooth muscle cells, GGCLT could reduce cell migration, but failed to affect cell viability and proliferation. In hepatocytes, GGCLT can reduce lipid accumulation, and this action was accompanied by the activation of AMPK, upregulation of PPARs, and downregulation of FAS. Pharmacological approach indicated that the latter two events contributing to the anti-lipogenesis is resulting from AMPK pathway, and the lipid lowering effect of GGCLT in hepatocytes is mediated by AMPK and PPARα pathways. Meanwhile, two of the major components of GGCLT, berberine and puerarin, also activated AMPK and decreased lipid accumulation in hepatocytes with berberine of higher efficacy. Besides in hepatocytes, AMPK signaling was also activated by GGCLT in vascular smooth muscle cells and macrophages.

Conclusions

These results demonstrate the anti-atherosclerotic action of Chinese medicine mixture GGCLT in ApoE^−/− atherosclerotic mouse model. Mechanistic study suggests that activation of AMPK and PPARα in hepatocytes leading to a decrease of lipid formation contributes to the beneficial action of GGCLT in atherosclerosis treatment.