Ciglitazone,a Peroxisome Proliferator-Activated Receptor Gamma Ligand,Inhibits Proliferation and Differentiation of Th17 Cells

Peroxisome proliferator-activated receptor gamma (PPARγ) was identified as a cell-intrinsic regulator of Th17 cell differentiation. Th17 cells have been associated with several autoimmune diseases, including experimental autoimmune encephalomyelitis (EAE), inflammatory bowel disease (IBD), and collagen-induced arthritis. In this study, we confirmed PPARγ-mediated inhibition of Th17 cell differentiation and cytokine production at an early stage. Treatment with ciglitazone, a PPARγ ligand, reduced both IL-1β-mediated enhancement of Th17 differentiation and activation of Th17 cells after polarization. For Th17 cell differentiation, we found that ciglitazone-treated cells had a relatively low proliferative activity and produced a lower amount of cytokines, regardless of the presence of IL-1β. The inhibitory activity of ciglitazone might be due to decrease of CCNB1 expression, which regulates the cell cycle in T cells. Hence, we postulate that a pharmaceutical PPARγ activator might be a potent candidate for treatment of Th17-mediated autoimmune disease patients.     

维甲酸受体功能及其在肿瘤治疗中的应用

目的对维甲酸受体功能、分子机制及其在肿瘤治疗中的应用进行综述,为以维甲酸受体为靶点的肿瘤治疗和新药研发提供参考。方法检索近年来国内外有关维甲酸受体的研究文献,针对其功能、分子机制以及肿瘤治疗方面的应用,进行分析和总结。结果维甲酸受体通过转录调节、翻译调节和磷酸化调节与其他多条信号通路相互联系、共同调节。维甲酸受体在肿瘤治疗中起到非常重要的作用,维甲酸类似物在诱导多种肿瘤细胞分化、逆转肿瘤细胞的恶性表型方面效果显著。结论维甲酸受体的调节过程极为复杂,因此在肿瘤发生发展及治疗中的作用还有待进一步的研究。     

Perfluorooctanoic acid induces mast cell-mediated allergic inflammation by the release of histamine and inflammatory mediators

Perfluorooctanoic acid (PFOA) has unique physical and chemical characteristics, water and oil repellency, thermal stability, and surfactant properties. PFOA has been regularly found in the blood of animals and humans worldwide, and has become an increasing concern because of its adverse effects in immune system. However, the role of PFOA in the allergic inflammation is not well-known. To further extend the immunotoxicity of PFOA, we examined the role of PFOA on the mast cell-mediated allergic inflammation and studied the possible mechanism of action. PFOA dose- and time-dependently increased histamine release from mast cells and serum histamine by the induction of intracellular calcium. PFOA exacerbated the IgE-dependent local allergic reaction in the mouse allergy model. PFOA induced gene expression of pro-inflammatory cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and IL-8 in mast cells. The inducing effect of PFOA on the pro-inflammatory cytokines was nuclear factor-κB, p38 mitogen-activated protein kinase, and caspase-1 dependent. Furthermore, the activation of cyclooxygenase-2 by PFOA suggests the induction of allergic inflammatory mediators by the PFOA. Our findings provide evidence that PFOA, the known immunotoxic agent, induces mast cell-derived allergic inflammatory reactions by histamine release and expression of pro-inflammatory cytokines.     

New Molecular Bioassays for the Estimation of the Teratogenic Potency of Valproic Acid Derivatives in Vitro: Activation of the Peroxisomal Proliferator-Activated Receptor (PPARδ)

Therapy with the antiepileptic drug valproic acid (2-propylpentanoic acid, VPA) during early pregnancy can cause teratogenic effects (neural tube defects) in humans and in mice. VPA and a teratogenic derivative specifically induce differentiation of F9 teratocarcinoma cells and activate PPARδ. We have now studied structure–activity relationships of 11 VPA-related compounds by quantitatively comparing their teratogenic potency with their effects in the two novel in vitro systems. Based on the induction of a Rous sarcoma virus (RSV) promoter-driven reporter gene, which is associated with the differentiation of F9 cells, a system suitable for high-throughput and quantitative screening was established. Structure–activity investigations showed that only teratogenic derivatives of VPA induced the response in F9 cells as well as activated the PPARδ-dependent reporter system in Chinese hamster ovary (CHO) cells. Increases in the length of the side chain in the VPA-related 2-alkyl-pentynoic acid generate more potent inducers in the cell-culture-based assays, which also show higher teratogenicity and embryonic lethality rates. Activation of PPARδ correlated well with the effects in the F9 cell assay and with teratogenic potency in vivo (p < 0.007). Evaluation of the effects of the presented set of compounds allows the conclusion that the in vitro systems faithfully reflect teratogenicity of VPA-related compounds. Whether the activation of PPARδ is causally related to the disruption of proper embryonic development or whether it reflects other yet unknown VPA-induced events remains to be established.     

High-dose dietary exposure of mice to perfluorooctanoate or perfluorooctane sulfonate exerts toxic effects on myeloid and B-lymphoid cells in the bone marrow and these effects are partially dependent on reduced food consumption

It is well established that exposure of mice to perfluorooctanoate (PFOA) or perfluorooctane sulfonate (PFOS) exerts adverse effects on the thymus and spleen. Here, we characterize the effects of a 10-day dietary treatment with these compounds (0.001–0.02%, w/w) on the bone marrow (BM) of mice. At a dose of 0.02%, both compounds reduced food consumption and caused atrophy of the thymus and spleen. At this same dose, histopathological and flow cytometric analysis revealed that (i) the total numbers of BM as well as the numbers of myeloid, pro/pre B, immature B and early mature B cells were all reduced significantly; and (ii) these adverse effects were reversed either partially or completely 10 days after withdrawal of these compounds. At the lower dose of 0.002%, only PFOA reduced the B-lymphoid cell population. Finally, mice fed an amount of diet equivalent to that consumed by the animals exposed to 0.02% PFOA also exhibited atrophy of the thymus and spleen, and a reduction in the number of B-lymphoid population, without affecting myeloid cells. Thus, in mice, immunotoxic doses of PFOA or PFOS induce adverse effects on the myeloid and B-lymphoid cells in the BM, in part as a consequence of reduced food consumption.     

GHB-Induced Cognitive Deficits During Adolescence and the Role of NMDA Receptor

We have earlier reported that γ-hydroxybutyric acid (GHB) disrupts the acquisition of spatial learning and memory in adolescent rats. GHB is known to interact with several neurotransmitter systems that have been implicated in cognitive functioning. The N-methyl-D-aspartate receptor (NR) -type of glutamate receptor is considered to be an important target for spatial learning and memory. Molecular mechanisms governing the neuroadptations following repeated GHB treatment in adolecent rats remain unknown. We examined the role of NMDA receptor in adolescent GHB-induced cognitive deficit. Adolescent rats were administered with GHB on 6 consecutive days, and surface-expressed NMDA receptor subunits levels were measured. GHB significantly decreased NR1 levels in the frontal cortex. Adolescent GHB also significantly reduced cortical NR2A subunit levels. Our findings support the hypothesis that adolescent GHB-induced cogntive deficits are associated with neuroadaptations in glutamatergic transmission, particulaly NR functioning in the frontal cortex.     

Fatty Acid Binding Receptors and Their Physiological Role in Type 2 Diabetes

G‐protein‐coupled receptors (GPCRs) respond to various physiological ligands such as photons, ions, and small molecules that include amines, fatty acids, and amino acids to peptides, proteins and steroids. Therefore, this family of proteins represents an attractive target for biopharmaceutical research [1]. The physiological role of fatty acids and other lipid molecules as important signal mediators is well studied in various metabolic pathways [2]. Acute administration of free fatty acids (FFAs) stimulates insulin release. Conversely, chronic exposure to high levels of free fatty acids leads to impairment of β cell function and lipotoxicity. However, the receptors through which these fatty acids and lipids act were unknown, until the identification of fatty acid binding receptors: GPR40, GPR41, GPR43, and GPR119. Based on their tissue‐expression profile, and pharmacologic analysis, the fatty acid binding receptors along with lipid binding receptor GPR119 are linked to diabetes and obesity. They play a critical role in the metabolic regulation of insulin release and glucose homeostasis. In this review, the mechanism of receptor activation, pharmacology, and the physiological functions of the fatty acid binding receptors will be discussed.     

白藓碱单用及联合全反式维甲酸对急性髓性白血病细胞的分化治疗作用

目的探索白藓碱单用及联合全反式维甲酸(ATRA)对急性髓性白血病细胞(AML)的分化治疗作用。方法不同浓度的白藓碱单独或联合ATRA作用于3株不同AML亚型的细胞株(NB4、U937和HL60),利用细胞计数考察细胞增殖抑制情况;通过PI染色结合流式细胞术检测细胞凋亡;检测细胞表面抗原CD11b和细胞核形态考察细胞分化;RT-PCR和Western blotting法观察细胞分化相关转录因子CEBPβ和PU.1的m RNA和蛋白水平。结果白藓碱单用及联合ATRA均能明显诱导AML细胞发生分化,表现为抑制细胞增殖、增加细胞表面CD11b的表达,使细胞核形态出现马蹄形甚至分叶形;白藓碱单用及联合ATRA均能在m RNA水平和蛋白水平上增加分化相关转录因子CEBPβ和PU.1的表达。结论白藓碱能够单独或协同ATRA诱导不同AML亚型细胞发生分化,并且其诱导分化作用可能是通过调控分化相关转录因子CEBPβ和PU.1引起的。     

Nephroprotective Role of Resveratrol and Ursolic Acid in Aristolochic Acid Intoxicated Zebrafish

The nephrotoxicity of aristolochic acid (AA) is well known, but information regarding the attenuation of AA-induced toxicity is limited. The aim of the present study was to study the nephroprotective effects of resveratrol (Resv) and ursolic acid (UA) in a zebrafish model. We used two transgenic lines, Tg(wt1b:EGFP) and Tg(gata1:DsRed), to evaluate the nephroprotective effects of Resv and UA by recording subtle changes in the kidney and red blood cell circulation. Our results demonstrated that both Resv and UA treatment can attenuate AA-induced kidney malformations and improve blood circulation. Glomerular filtration rate assays revealed that both Resv and UA treatment can restore renal function (100% for Mock; 56.1% ± 17.3% for AA-treated; 80.2% ± 11.3% for Resv+AA; and 83.1% ± 8.1% for UA+AA, n = 15). Furthermore, real-time RT-PCR experiments showed that pre-treatment with either Resv or UA suppresses expression of pro-inflammatory genes. In conclusion, our findings reveal that AA-induced nephrotoxicities can be attenuated by pre-treatment with either Resv or UA. Therefore, we believe that zebrafish represent an efficient model for screening AA-protective natural compounds.     

法尼酯X受体调控因素及配体的研究进展

法尼酯X受体（Farnesoid X Receptor,FXR）属于核激素受体超家族中的一员,作为一种胆汁酸受体和胆汁酸生物合成的生物感受器,参与机体多种生理活动。因此揭示FXR转录表达的调控因素以及寻找具有选择性和高活性的FXR配体,为新药研发提供新思路具有重要的意义。因而对FXR表达调控和配体的最新研究进行综述。     

Synthesis and the Stereoselective Enzymatic Hydrolysis of Flurbiprofen-Basic Amino Acid Ethyl Esters

Abstract

Ethyl esters of flurbiprofen L-arginine (FP-Arg-OH), flurbiprofen L-lysine (FP-Lys-OH) and flurbiprofen p-guanidino-L-phenylalanine (FP-GPA-OH) were synthesized and then the release of flurbiprofen enantiomers from these derivatives in the presence of trypsin (Tp), carboxypeptidase B (CPB) and car-boxypeptidase Y (CPY) were examined in order to evaluate their availability as prodrugs for flurbiprofen (FP). The ester bonds of the three racemic FP derivatives were hydrolyzed by Tp at about 3 to 20 times the rates of N-benzoyl-L-arginine ethyl ester (Bz-Arg-OEt), a specific substrate for Tp. (R)- FP was released faster than (S)-FP by either CPB or CPY from both FP-Arg-OH and FP-Lys-OH. On the other hand, FP-GPA-OH was not hydrolyzed at all by CPB and the hydrolysis rate of this compound by CPY was very slow. (S)-Flurbiprofen L-arginine ethyl ester ((S)-FP-Arg-OEt) was separated from (R)-FP-Arg-OEt by high-performance liquid chromatography. A comparison of the kinetic parameters for the tryptic hydrolysis of the two optically active FP-Arg-OEt diastereomers and those of Bz-Arg-OEt suggested that the orientation of the scissile bond in each diastereomer to the catalytic center of Tp is more favorable than that of Bz-Arg-OEt. However, no significant difference was found between the kinetic parameters for the two diastereomers, suggesting that the orientational difference between (S)-FP and (R)-FP in the diastereomers does not have any effect on the tryptic hydrolysis of the ester bond. On the other hand, for the hydrolysis of the diastereomers by CPB and CPY, the kcat values for (R)-FP-Arg-OH were larger than those for (S)-FP-Arg-OH, while the Km values for the former were almost the same as those for the latter. These results indicate that the orientation of the scissile bond in (R)-FP-Arg-OH to the catalytic sites of CPB and CPY was more favorable than that in (S)-FP-Arg-OH. (S)-FP-Arg-OEt is thus considered to be a promising optically active water-soluble prodrug for the sustained release of FP.     

Reaction of 5-Aminosalicylic Acid with Peroxyl Radicals: Protection and Recovery by Ascorbic Acid and Amino Acids

Purpose The aims of the study are to analyze the interaction between 5-aminosalicylic acid (5-ASA) and peroxyl radicals and to evaluate the effect of some endogenous compounds such as ascorbic acid and amino acids on the oxidation of 5-ASA induced by 2,2′-azo-bis(2-amidinopropane) dihydrochloride. Methods The consumption and/or the recovery of 5-ASA (7.6 μM) exposed to a peroxyl radical source [2,2′-azo-bis(2-amidinopropane)] was followed by techniques such as spectrofluorescence, high-performance liquid chromatography, and differential pulse voltammetry. Results 5-Aminosalicylic acid was found to readily react with peroxyl radicals at micromolar concentrations and to protect c-Phycocyanin in a very similar fashion to that shown by Trolox. Exposure of 5-ASA to peroxyl radicals led to its oxidation into the corresponding quinone-imine. Disappearance of 5-ASA was prevented by tryptophan, cysteine, glutathione, and ascorbic acid. Furthermore, some of these compounds induced the partial (cysteine and glutathione) or total (ascorbic acid) recovery of 5-ASA when added after its almost total consumption. Conclusions 5-Aminosalicylic acid is a very efficient peroxyl radical scavenger. The 5-ASA oxidation by peroxyl radicals was prevented by ascorbic acid, cysteine, and glutathione. In addition, 5-ASA can be regenerated by these endogenous compounds, which would be a valuable mechanism to preserve 5-ASA in tissues undergoing oxidative stress conditions.     

The Role of the Neurokinin-1 Receptor in Stress-Induced Reinstatement of Alcohol and Cocaine Seeking

Neurokinin-1 receptors (NK1Rs) have been shown to mediate alcohol and opiate, but not cocaine reward in rodents. We recently reported that NK1R antagonism also blocks stress-induced reinstatement of alcohol seeking in rats, but it is presently unknown whether these antirelapse properties extend to other drug classes. Although some work has suggested that intracranial substance P (SP) infusion reinstates cocaine seeking following extinction, no studies have indicated a direct role for the NK1R in reinstatement of cocaine seeking. Here, we explored the effect of the NK1R antagonist L822429 on yohimbine-induced reinstatement of alcohol or cocaine seeking in Long–Evans rats. Consistent with our previous findings with footshock-induced reinstatement of alcohol seeking in Wistar rats, we found that L822429 attenuates yohimbine-induced reinstatement of alcohol seeking, but does not affect baseline alcohol self-administration. We observed a similar suppression of yohimbine-induced reinstatement of cocaine seeking by L822429, and found that Long–Evans rats exhibit greater sensitivity to NK1R antagonism than Wistar rats. Accordingly, Long–Evans rats exhibit differences in the expression of NK1Rs in some subcortical brain regions. Combined, our findings suggest that while NK1R antagonism differentially influences alcohol- and cocaine-related behavior, this receptor mediates stress-induced seeking of both drugs.     

复方鱼腥草胶囊的抗炎及免疫功能调节作用

目的探讨复方鱼腥草胶囊 (FYC)的抗炎作用及其对免疫功能的影响。方法采用二甲苯耳肿胀、醋酸致腹膜通透性增高及棉球肉芽肿等炎症模型 ,碳粒廓清、迟发型超敏反应及溶血素等测定免疫功能的模型。结果FYC可显著拮抗二甲苯所致的小鼠耳肿胀 ,降低腹膜通透性 ,抑制肉芽肿增生 ,提高免疫功能低下动物的特异性及非特异性免疫功能。结论FYC可拮抗各种致炎因子所致的炎症反应 ,对Cy所致免疫功能低下小鼠有免疫增强作用。