SYNTHESIS OF 6-AMINO, 6-METHOXY AND 6-ETHOXY PURINENUCLEOSIDE DERIVATIVES

A convenient route for the conversion of inosine to the corresponding 6-amino, 6-methoxy and 6-ethoxy derivatives is reported. This conversion can be achieved by ammoniation or etherification of the 6-pyridinium intermediate(3) which can be readily produced under mild reaction conditions. The chemistry and characterization of these compounds are presented, A plausible mechanism of the reaction is proposed.

Virtual screening and optimization of typeⅡ inhibitors of JAK2 from a natural product library

OBJECTIVE To utilize a structure-based lead optimization approach to generate novel natural product-like typeⅡ inhibitors of JAK2 using the DOLPHIN protocol.METHODS Initially,the DOLHPIN computational protocol was employed to convert an active(DFG-in)conformation of JAK2 into a typeⅡ-compatible conformation,which was used as a model for the structure-based virtual screening of 150 000 natural product-like compounds in silico.The novel biflavonoid analogues were designed and synthesized based on the structure of lead compound and then tested for JAK2 and STAT3 inhibitory activity,cytotoxicity and HCV antiviral activity.RESULTS The top eleven highest-scoring compounds were generated from the initial high-throughput virtual screening.Amentoflavone 1a,a biflavonoid from the Chinese plant Gingko biloba,emerged as a promising candidate for further biological evaluation.In dose-response experiments,amentoflavone 1ainhibited JAK2 activity in a concentration dependent fashion with an IC50 value of 5μmol·L-1.As a proof-of-concept,we designed nine analogues 1b-1j with the addition of one or more aliphatic side chains to the biflavonoid scaffold of 1a.The octyl(C8)analogue 1bdisplayed superior potency against JAK2 activity and HCV activity compared to the parent compound 1a,validating the structure-based lead optimization approach used in this study.Moreover,kinetic analysis indicated that analogue 1bexhibited a non-competitive mode of inhibition,suggesting that this compound may be a putative typeⅡ inhibitor of JAK2.CONCLUSION Amentoflavone 1ahas been identified as a JAK2 inhibitor by structure-based virtual screening of a natural product library.In silico optimization using the DOLPHIN model yielded analogues with enhanced potency against JAK2 activity and HCV activity in cellulo.Molecular modeling and kinetic experiments suggested that the analogues may function as typeⅡ inhibitors of JAK2.

Development of an orally bioavailable selective inhibitor of the menin-MLL

The protein–protein interaction between menin and mixed lineage leukemia(MLL)plays an important role in the development of human hepatocellular carcinogenesis(HCC)and is associated with poor prognosis of HCC patients.1,2 Hence,interrupting the menin-MLL interaction is an attractive strategy in cancer treatment,particularly for liver cancer.3,4 In this study,we identified complex C1 as the first rhodium(III)-based orally bioavailable selective inhibitor of the menin-MLL interaction for HCC.

Exploring pathogenesis in subjects with subjective Tinnitus having kidney deficiency pattern in terms of Traditional Chinese Medicine based on serum metabolic profiles

OBJECTIVE: To investigate the metabolic pathogenesis in subjects with subjective tinnitus(ST)having kidney deficiency pattern(KDP)(ST/KDP) in terms of Traditional Chinese Medicine.METHODS: Three groups of subjects, including healthy individuals, subjects with ST/KDP, and subjects who were healthy initially and then developed ST/KDP one year later(healthy → ST/KDP),were recruited for this study. Serum metabolic profiles of all subjects were analyzed using ultra-performance liquid chromatography coupled with quadruple-time-of-flight mass spectrometry. The metabolic characteristics of the ST/KDP subjects were determined, and the corresponding biomarkers were predicted. The metabolomics data from the healthy → ST/KDP subjects were collected for further verification.RESULTS: Twelve metabolites in the ST/KDP subjects were different from those of the healthy control subjects. Of these metabolites, according to the prediction, except for octanoic acid, other metabolites might characterize ST/KDP. Ten metabolites at the outcome ST/KDP stage were different from those at the initial(control) stage. Through the comparison of these metabolites with the predicted metabolites, five common metabolites, including upregulated glutamate, serotonin, oroticacid and 8-oxoguanine, as well as downregulated taurine, were found. These common metabolites were significantly associated with canonical pathways including calcium signaling, γ-aminobutyric acid(GABA) receptor signaling, purine and pyrimidine biosynthesis, taurine biosynthesis, and serotonin receptor signaling.CONCLUSION: The metabolic pathogenesis in ST/KDP subjects was characterized by upregulated glutamate, serotonin, orotic acid and 8-oxoguanine, as well as downregulated taurine, additionally, perturbations of calcium signaling, GABA receptor signaling, purine and pyrimidine biosynthesis, taurine biosynthesis, and serotonin receptor signaling.

转基因小鼠中人清道夫受体AI基因的稳定遗传和特异表达

为阐明人清道夫受体AI (hSR -AI)的功能及在动脉粥样硬化发生中的作用 ,本研究首先构建了含鼠tie- 1启动子和人清道夫受体AIcDNA的表达载体 ,经酶切及测序鉴定后 ,用显微注射的方法将制备好的tie - 1-hSR-A -BGHpolyA片段注入受精卵 ,将注射后存活的受精卵移入ICR假孕母鼠 ,产下的仔鼠经聚合酶链反应和Southernblot分析 ,筛选出整合有外源目的基因的阳性转基因鼠 ;对小鼠组织RNA行逆转录聚合酶链反应及组织切片免疫组织化学染色 ,检测人清道夫受体AI在小鼠体内的表达水平及表达部位 ;光镜及电镜观察转基因鼠血管及其它组织的病理变化。结果发现 ,重组Tie - 1/hSR -AI质粒中鼠tie - 1启动子和人清道夫受体AIcDNA序列正确 ,显微注射后存活的 5 6 1枚受精卵分别移入 19只ICR假孕母鼠 ,有 13只受孕 ,共产下 5 6只仔鼠 ,存活 5 4只 ,经过整合检测 ,检出 7只阳性鼠 ,整合效率为 13%。在G1、G2、G3代及纯合子转基因鼠中PCR阳性率分别为 47.8%、71.3%、75 .0 %和 10 0 %。 5只雄性转基因鼠的主动脉、肾、肝等组织中均有人清道夫受体AI表达 ,且主要集中在血管的内皮细胞上 ;转基因鼠主动脉内皮细胞明显水肿 ,表面呈多囊状和虫蚀样改变 ,胞质中有较多水泡 ,中膜有糖原沉积样灶性病变 ,平滑肌细胞中亦有水肿 ;血浆?

Pathway-selective suppression of chemokine receptor signaling in B cells by LPS through downregulation of PLC-b2

Lymphocyte activation leads to changes in chemokine receptor expression.There are limited data,however,on how lymphocyte activators can alter chemokine signaling by affecting downstream pathways.We hypothesized that B cell-activating agents might alter chemokine responses by affecting downstream signal transducers,and that such effects might differ depending on the activator.We found that activating mouse B cells using either anti-IgM or lipopolysaccharide(LPS)increased the surface expression of CCR6 and CCR7 with large increases in chemotaxis to their cognate ligands.By contrast,while anti-IgM also led to enhanced calcium responses,LPS-treated cells showed only small changes in calcium signaling as compared with cells that were freshly isolated.Of particular interest,we found that LPS caused a reduction in the level of B-cell phospholipase C(PLC)-b2 mRNA and protein.Data obtained using PLC-b22/2 mice showed that the b2 isoform mediates close to one-half the chemokine-induced calcium signal in resting and anti-IgM-activated B cells,and we found that calcium signals in the LPS-treated cells were boosted by increasing the level of PLC-b2 using transfection,consistent with a functional effect of downregulating PLC-b2.Together,our results show activator-specific effects on responses through B-cell chemokine receptors that are mediated by quantitative changes in a downstream signal-transducing protein,revealing an activity for LPS as a downregulator of PLC-b2,and a novel mechanism for controlling chemokine-induced signals in lymphocytes.

Direct Observation of Arthrobacter 4-Hydroxybenzoyl-Coenzyme A Thioesterase Catalysis complexes using Electrospray Ionization Mass Spectrometry

Investigating enzymatic reaction in multimeric enzymes is utmost interest to improve our understanding of the mechanism of enzymatic reaction and regulation. In this study,

Transcriptome-wide identification of differentially expressed genes and long non-coding RNAs in nitroglycerin-tolerant rat aorta

Tolerance to nitroglycerin(GTN)greatly limits its long-time application,and the underlying mechanism remains largely unexplored.In the present study,we aimed to investigate the comprehensive changes in the transcriptome of rat aorta tolerant to GTN by analyzing lncRNA expression.We employed the RNA sequencing(RNA-seq)technique to identify mRNAs and lncRNAs.Ingenuity pathway analysis(IPA)was used for pathway and functional analysis.RT-qPCR was used to validate the RNA-seq results.We identified 22788 genes(reads per kilobase million[RPKM]>0.1,14720 protein-coding genes and 4408 lncRNAs),including 115 differentially expressed(DE)mRNAs(65 up-regulated and 50 down-regulated)and 104 DE lncRNAs(56 up-regulated and 48 down-regulated),in GTN-tolerant aortas.IPA revealed the inhibition of a canonical pathway“Signaling by Rho Family GTPases”and alteration in six upstream regulators.Functional analysis showed that 11 genes were related to“disorder of blood pressure”.We predicted the cis-target genes of DE lncRNAs by the analysis of their neighboring genes.The results revealed the 28 DE lncRNAs adjacent to the 26 protein-coding genes.Many DE mRNAs and cis-target genes of DE lncRNAs have been implicated in the regulation of blood pressure or cell contraction.These results suggested that the dysregulated mRNAs and lncRNAs contributed to the development of GTN tolerance and could serve as potential targets to prevent and reverse GTN tolerance.

Therapeutic strategies for the costimulatory molecule OX40 in T-cell-mediated immunity

The T cell co-stimulatory molecule OX40 and its cognate ligand OX40 L have attracted broad research interest as a therapeutic target in T cell-mediated diseases.Accumulating preclinical evidence highlights the therapeutic efficacy of both agonist and blockade of the OX40-OX40 L interaction.Despite this progress,many questions about the immuno-modulator roles of OX40 on T cell function remain unanswered.In this review we summarize the impact of the OX40-OX40 L interaction on T cell subsets,including Th1,Th2,Th9,Th17,Th22,Treg,Tfh,and CD8+T cells,to gain a comprehensive understanding of anti-OX40 mAb-based therapies.The potential therapeutic application of the OX40-OX40 L interaction in autoimmunity diseases and cancer immunotherapy are further discussed;OX40-OX40 L blockade may ameliorate autoantigen-specific T cell responses and reduce immune activity in autoimmunity diseases.We also explore the rationale of targeting OX40-OX40 L interactions in cancer immunotherapy.Ligation of OX40 with targeted agonist anti-OX40 mAbs conveys activating signals to T cells.When combined with other therapeutic treatments,such as anti-PD-1 or anti-CTLA-4 blockade,cytokines,chemotherapy,or radiotherapy,the anti-tumor activity of agonist anti-OX40 treatment will be further enhanced.These data collectively suggest great potential for OX40-mediated therapies.