Mechanism of anti-hyperuricemia of isobavachin based on network pharmacology and molecular docking.

BACKGROUND: Hyperuricemia is a more popular metabolic disease caused by a disorder of purine metabolism. Our previous study firstly screened out a natural product Isobavachin as anti-hyperuricemia targeted hURAT1 from a Chinese medicine Haitongpi (Cortex Erythrinae). In view of Isobavachin's diverse pharmacological activities, similar to the Tranilast (as another hURAT1 inhibitor), our study focused on its potential targets and molecular mechanisms of Isobavachin anti-hyperuricemia based on network pharmacology and molecular docking. METHODS: First of all, the putative target genes of compounds were screen out based on the public databases with different methods, such as SwissTargetPerdiction, PharmMapper and TargetNet,etc. Then the compound-pathways were obtained by the compounds' targets gene from David database for Gene Ontology (GO) function enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways enrichment analysis. The cross pathways of compound-pathways and the diseases pathways of hyperuricemia from Comparative Toxicogenomics Database were be considered as the compound-disease pathways. Next, based on the compound-disease pathways and the PPI network, the core targets were identified based on the retrieved disease-genes. Finally, the compound-target-pathway-disease network was constructed by Cytoscape and the mechanism of isobavachin anti-hyperuricemia was discussed based on the network analysis. RESULTS: Our study demonstrated that there were five pathways involved in Isobavachin against hyperuricemia, including Drug metabolism-other enzymes, Metabolic pathways, Bile secretion, Renin-angiotensin system and Renin secretion. Among the proteins involved in these pathways, HPRT1, REN and ABCG2 were identified as the core targets associated with hyperuricemia, which regulated the five pathways mentioned above. It is quite different from that of Tranilast, which involved in the same pathways except Bile secretion instead of purine metabolism. CONCLUSION: This study revealed Isobavachin could regulate the pathways including Drug metabolism-other enzymes, Metabolic pathways, Bile secretion, Renin-angiotensin system, Renin secretion by core targets HPRT1, REN and ABCG2, in the treatment of hyperuricemia effect. Among them, the Bile secretion regulated by ABCG2 probably would be a novel pathway. Our work provided a theoretical basis for the pharmacological study of Isobavachin in lowering uric acid and further basic research.

ML365 inhibits TWIK2 channel to block ATP-induced NLRP3 inflammasome.

Dysregulation of NLRP3 inflammasome results in uncontrolled inflammation, which participates in various chronic diseases. TWIK2 potassium channel mediates potassium efflux that has been reported to be an essential upstream mechanism for ATP-induced NLRP3 inflammasome activation. Thus, TWIK2 potassium channel could be a potential drug target for NLRP3-related inflammatory diseases. In the present study we investigated the effects of known K2P channel modulators on TWIK2 channel expressed in a heterologous system. In order to increase plasma membrane expression and thus TWIK2 currents, a mutant channel with three mutations (TWIK2I289A/L290A/Y308A) in the C-terminus was expressed in COS-7 cells. TWIK2 currents were assessed using whole-cell voltage-clamp recording. Among 6 known K2P channel modulators tested (DCPIB, quinine, fluoxetine, ML365, ML335, and TKDC), ML365 was the most potent TWIK2 channel blocker with an IC50 value of 4.07 ± 1.5 µM. Furthermore, ML365 selectively inhibited TWIK2 without affecting TWIK1 or THIK1 channels. We showed that ML365 (1, 5 µM) concentration-dependently inhibited ATP-induced NLRP3 inflammasome activation in LPS-primed murine BMDMs, whereas it did not affect nigericin-induced NLRP3, or non-canonical, AIM2 and NLRC4 inflammasomes activation. Knockdown of TWIK2 significantly impaired the inhibitory effect of ML365 on ATP-induced NLRP3 inflammasome activation. Moreover, we demonstrated that pre-administration of ML365 (1, 10, 25 mg/kg, ip) dose-dependently ameliorated LPS-induced endotoxic shock in mice. In a preliminary pharmacokinetic study conducted in rats, ML365 showed good absolute oral bioavailability with F value of 22.49%. In conclusion, ML365 provides a structural reference for future design of selective TWIK2 channel inhibitors in treating related inflammatory diseases.

CDER167, a dual inhibitor of URAT1 and GLUT9, is a novel and potent uricosuric candidate for the treatment of hyperuricemia.

Urate transporter 1 (URAT1) and glucose transporter 9 (GLUT9) are important targets for the development of uric acid-lowering drugs. We previously showed that the flexible linkers of URAT1 inhibitors could enhance their potency. In this study we designed and synthesized CDER167, a novel RDEA3710 analogue, by introducing a linker (methylene) between the naphthalene and pyridine rings to increase flexibility, and characterized its pharmacological and pharmacokinetics properties in vitro and in vivo. We showed that CDER167 exerted dual-target inhibitory effects on both URAT1 and GLUT9: CDER167 concentration-dependently inhibited the uptake of [14C]-uric acid in URAT1-expressing HEK293 cells with an IC50 value of 2.08 ± 0.31 µM, which was similar to that of RDEA3170 (its IC50 value was 1.47 ± 0.23 µM). Using site-directed mutagenesis, we demonstrated that CDER167 might interact with URAT1 at S35 and F365. In GLUT9-expressing HEK293T cells, CDER167 concentration-dependently inhibited GLUT9 with an IC50 value of 91.55 ± 15.28 µM, whereas RDEA3170 at 100 µM had no effect on GLUT9. In potassium oxonate-induced hyperuricemic mice, oral administration of CDER167 (10 mg·kg-1 · d-1) for 7 days was more effective in lowering uric acid in blood and significantly promoted uric acid excretion in urine as compared with RDEA3170 (20 mg·kg-1 · d-1) administered. The animal experiment proved the safety of CDER167. In addition, CDER167 displayed better bioavailability than RDEA3170, better metabolic stability and no hERG toxicity at 100 µM. These results suggest that CDER167 deserves further investigation as a candidate antihyperuricemic drug targeting URAT1 and GLUT9.

Versatile Nanodrugs Containing Glutathione and Heme Oxygenase 1 Inhibitors Enable Suppression of Antioxidant Defense System in a Two-Pronged Manner for Enhanced Photodynamic Therapy.

The antioxidant defense system in malignant cells, which involves antioxidant enzymes and antioxidant molecules, is an innate barrier to photodynamic therapy (PDT). Because of the complexity of the endogenous antioxidant mechanisms of these cells, simply inhibiting individual antioxidant pathways has a limited effect on improving the lethality of ROS. To enhance the efficacy of PDT for tumor treatment, a versatile nanoparticle (NP)-based drug is developed, which the authors call PZB NP, containing the glutathione inhibitor l-buthionine sulfoximine (BSO) and the heme oxygenase 1 (HO-1) inhibitor protoporphyrin zinc(II) (ZnPP) to suppress the innate antioxidant defense system of cancer cells in a two-pronged manner. BSO reduces intracellular glutathione levels to minimize ROS elimination and protein protection during PDT, and ZnPP inhibits the ROS-stimulated upregulation of the antioxidant HO-1, thus preventing ROS removal by cells after PDT. Thus, BSO and ZnPP synergistically suppress the antioxidant defense systems of cancer cells both during and after protoporphyrin-IX-mediated PDT in a two-pronged manner, resulting in tumor cell death through excess oxidative pressure. The results demonstrate that the construction of nanodrugs having dual antioxidation defense suppression properties is a promising route for the development of highly efficient ROS-based therapies.

Identification and characterization of a series of novel HCN channel inhibitors.

Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels play a critical role in controlling pacemaker activity in both heart and nervous system. Developing HCN channel inhibitors has been proposed to be an important strategy for the treatment of pain, heart failure, arrhythmias, and epilepsy. One HCN channel inhibitor, ivabradine, has been clinically approved for the treatment of angina pectoris and heart failure. In this study, we designed and synthesized eight alkanol amine derivatives, and assessed their effects on HCN channels expressed in COS7 cells using a whole-cell patch clamp method. Among them, compound 4e displayed the most potent inhibitory activity with an IC50 of 2.9 ± 1.2 µM at - 120 mV on HCN2 channel expressed in COS7 cells. Further analysis revealed that application of compound 4e (10 µM) caused a slowing of activation and a hyperpolarizing shift (ΔV1/2 = - 30.2 ± 2.9 mV, n = 5) in the voltage dependence of HCN2 channel activation. The inhibitory effect of compound 4e on HCN1 and HCN4 channel expressed in COS7 cells was less potent with IC50 of 17.2 ± 1.3 and 7.3 ± 1.2 µM, respectively. Besides, we showed that application of compound 4e (10 µM) inhibited Ih and action potential firing in acutely dissociated mouse small dorsal root ganglion neurons. Our study provides a new strategy for the design and development of potent HCN channel inhibitors.

In Situ Detection of Plasma Exosomal MicroRNA-1246 for Breast Cancer Diagnostics by a Au Nanoflare Probe.

Breast cancer is the second cause of cancer mortality in women globally. Early detection, treatment, and metastasis monitoring are of great importance to favorable prognosis. Although conventional diagnostic methods, such as breast X-ray mammography and image positioning biopsy, are accurate, they could cause radioactive or invasive damage to patients. Liquid biopsy as a noninvasive method is convenient for repeated sampling in clinical cancer prognostic, metastatic evaluation, and relapse monitoring. MicroRNAs encased in exosomes circulating in biofluids are promising candidate cancer biomarkers because of their cancer-specific expression profiles. Here, we report an in situ detection of microRNA-1246 (miR-1246) in human plasma exosomes as breast cancer biomarker by a nucleic acid functionalized Au nanoflare probe. Needing neither time-consuming and costly isolation of exosomes from the plasma sample nor transfection means, the Au nanoflare probe can directly enter the plasma exosomes to generate fluorescent signal quantitatively by specifically targeting miR-1246. Only 40 µL of plasma is needed to incubate 4 h with the probe, giving signal sensitive enough to distinguish samples of breast cancer to normal control. Using plasma miR-1246 level detected by our assay as a marker, we differentiated 46 breast cancer patients from 28 healthy controls with 100% sensitivity and 92.9% specificity at the best cutoff. This simple, accurate, sensitive, and cost-effective liquid biopsy by the Au nanoflare probe is potent to be developed as a noninvasive breast cancer diagnostic assay for clinical adaption.

Zwitterionic Manganese and Gadolinium Metal-Organic Frameworks as Efficient Contrast Agents for in Vivo Magnetic Resonance Imaging.

Two water-stable three-dimensional Mn- and Gd-based metal-organic frameworks (MOFs), {[Mn2(Cmdcp)2(H2O)2]·H2O}n (1) and {[Gd(Cmdcp)(H2O)3](NO3)·3H2O}n (2, H3CmdcpBr = N-(4-carboxy benzyl)-(3,5-dicarboxyl)pyridinium bromide), have been prepared and analyzed. In vitro magnetic resonance imaging indicated that MOFs 1 and 2 possess relaxivity r1 values of 17.50 and 13.46 mM-1·S-1, respectively, which are superior to that of the control Gd-DTPA (r1 = 4.87 mM-1·S-1, DTPA = diethylene triamine pentaacetate). MOFs 1 and 2 also possessed good biocompatibility and low cytotoxicity against a model cell line. In vivo magnetic resonance images of treated Kunming mice indicated that kidneys showed remarkably positive signal enhancement after 15 min with intravenous administration of MOF 1 and the hyperintensity of both kidneys persisted for about 240 min with no obvious tissue damage. MOF 1 is therefore promising in vivo probes for imaging intravascular diseases and renal dysfunction.

miR-133a Promotes TRAIL Resistance in Glioblastoma via Suppressing Death Receptor 5 and Activating NF-κB Signaling.

Recombinant tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), as a novel cancer therapeutic, is being tested in phase II and III clinical trials; however, TRAIL resistance remains a big obstacle preventing its clinical application. Considering that TRAIL-induced apoptosis through death receptors DR4 and DR5, their activation may be an alternative pathway to suppress TRAIL resistance. In this study, a negative correlation between DR5 expression and TRAIL resistance was observed, and miR-133a was predicted to be the most promising candidate to suppress DR5 expression. Further investigation demonstrated that miR-133a knockdown dramatically suppressed TRAIL resistance in glioblastoma in vitro and in vivo. An NF-κB family member, phosphorylated IκBα (P-IκBα), was shown to be stimulated by miR-133a, leading to the activation of this signaling. Finally, miR-133a was found to be inversely correlated with DR5 expression in human clinical specimens. In conclusion, our data demonstrate that miR-133a promotes TRAIL resistance in glioblastoma by suppressing DR5 expression and activating NF-κB signaling.

Usp5 functions as an oncogene for stimulating tumorigenesis in hepatocellular carcinoma.

As deubiquitinases, several ubiquitin specific protease members have been reported to mediate tumorigenesis. Although ubiquitin specific protease 5 (Usp5) was previously demonstrated to suppress p53 transcriptional activity and DNA repair, its role in carcinogenesis remains elusive. In this study, we sought to define a novel role of Usp5 in tumorigenesis. It was found that Usp5 was significantly upregulated in hepatocellular carcinoma (HCC) cells and most clinical specimens. Further functional investigation also showed that Usp5 knockdown suppressed cell proliferation, migration, drug resistance and induced apoptosis; on the other hand, Usp5 overexpression promoted colony formation, migration, drug resistance and tumorigenesis. Additionally, the inactivated p14ARF-p53 signaling was observed in Usp5 overexpressed HCC cells, while this signaling was activated by Usp5 knockdown. Therefore, our data demonstrated that Usp5 contributed to hepatocarcinogenesis by acting as an oncogene, which provides new insights into the pathogenesis of HCC and explores a promising molecular target for HCC diagnosis and therapy.

Ubiquitin specific peptidase 5 mediates Histidine-rich protein Hpn induced cell apoptosis in hepatocellular carcinoma through P14-P53 signaling.

Hpn is a small histidine-rich cytoplasmic protein from Helicobacter pylori and has been recognized as a high-risk factor for several cancers including gastric cancer, colorectal cancer, and MALT lymphoma. However, the relationship between Hpn and cancers remains elusive. In this study, we discovered that Hpn protein effectively suppressed cell growth and induced apoptosis in hepatocellular carcinoma (HCC). A two-dimensional gel electrophoresis and mass spectrometry-based comparative proteomics was performed to find the molecular targets of Hpn in HCC cells. It was identified that twelve proteins were differentially expressed, with USP5 being one of the most significantly downregulated protein. The P14ARF -P53 signaling was activated by USP5 knockdown in HCC cells. Furthermore, USP5 overexpression significantly rescued the suppressive effect of Hpn on the viability of HCC cells. In conclusion, our study suggests that Hpn plays apoptosis-inducing roles through suppressing USP5 expression and activating the P14ARF -P53 signaling. Therefore, Hpn may be a potential candidate for developing novel anti-HCC drugs.

H19 mediates methotrexate resistance in colorectal cancer through activating Wnt/ß-catenin pathway.

Colorectal cancer (CRC) is a common malignancy, most of which remain unresponsive to chemotherapy. As one of the earliest cytotoxic drugs, methotrexate (MTX) serves as an anti-metabolite and anti-folate chemotherapy for various cancers. Unfortunately, MTX resistance prevents its clinical application in cancer therapy. Thereby, overcoming the drug resistance is an alternative strategy to maximize the therapeutic efficacy of MTX in clinics. Long noncoding RNAs (lncRNAs) have gained widespread attention in recent years. More and more emerging evidences have demonstrated that they play important regulatory roles in various biological activities and disease progression including drug resistance. In the present study, a MTX-resistant colorectal cell line HT-29 (HT-29-R) was developed, which displayed the active proliferation and shortened cell cycle. LncRNA H19 was found to be significantly upregulated in this resistant cell line. Further investigation showed that H19 knockdown sensitized the MTX resistance in HT-29-R cells while its overexpression improved the MTX resistance in the parental cells, suggesting that H19 mediate MTX resistance. The Wnt/ß-catenin signaling was activated in HT-29-R cells, and H19 knockdown suppressed this signaling in the parental cells. In conclusion, H19 mediated MTX resistance via activating Wnt/ß-catenin signaling, which help to develop H19 as a promising therapeutic target for MTX resistant CRC.

Synthesis and potent inhibitory activities of carboxybenzyl-substituted 8-(3-(R)-aminopiperidin-1-yl)-7-(2-chloro/cyanobenzyl)-3-methyl-3,7-dihydro-purine-2,6-diones as dipeptidyl peptidase IV (DPP-IV) inhibitors.

Fourteen 3-methyl-3,7-dihydro-purine-2,6-dione derivatives 1-14 bearing carboxybenzyl and 2-chloro/cyanobenzyl groups at the N-1 and N-7 positions, respectively, were synthesized as dipeptidyl peptidase IV (DPP-IV) inhibitors. These compounds were characterized on the basis of NMR ((1)H and (13)C) and ESI MS data. In vitro bioassay indicates that most of these compounds showed moderate to good inhibitory activities against DPP-IV. Among them, compound 13 (IC50=36 nM) exhibited comparable activity with a positive control, Sitagliptin (IC50=16 nM). In addition, the structure-activity relationship of these compounds is also briefly discussed.

Rapamycin promoted thrombosis and platelet adhesion to endothelial cells by inducing membrane remodeling.

BACKGROUND: Recently, evidence indicated that the rapamycin-eluting stent which was used worldwide may contribute to an increased risk for thrombosis. On the contrary, other researchers found it was safe. Thus, it is necessary to clarify the effect of rapamycin on thrombosis and the corresponding mechanisms. RESULTS: The effects of rapamycin in vivo were evaluated by modified deep vein thrombosis animal model. The platelets were from healthy volunteers and the platelet-endothelium (purchased from ATCC) adhesion in cultured endothelial cells was assessed. Membrane rufflings in endothelial cells were examined by confocal and electron microscope. Thrombus formation increased in rats that were injected with rapamycin. Electron microscope analysis exhibited microvilli on the rapamycin-treated endothelium in rats. Rapamycin enhanced membrane ruffling in human umbilical vein endothelial cells (HUVECs) and adhesion of platelets to HUVECs. The platelet-HUVECs adhesion was attenuated when cells were treated with cytochalacin B. Inhibition of autophagy by 3-methyladenine led to suppression of membrane ruffles in HUVECs and augmentation of platelet-endothelial adhesion. CONCLUSIONS: In conclusion, we found that endothelial membrane remodeling induced by rapamycin is crucial for the adhesion of platelets to endothelial cells and thereby for thrombosis in vivo, and that the endothelial membrane remodeling is autophagy dependent.

Plumbagin induces apoptotic and autophagic cell death through inhibition of the PI3K/Akt/mTOR pathway in human non-small cell lung cancer cells.

Plumbagin (PLB) has shown anti-cancer activity but the mechanism is unclear. This study has found that PLB has a potent pro-apoptotic and pro-autophagic effect on A549 and H23 cells. PLB arrests cells in G2/M phase, and increases the intracellular level of reactive oxygen species in both cell lines. PLB dose-dependently induces autophagy through inhibition of PI3K/Akt/mTOR pathway as indicated by reduced phosphorylation of Akt and mTOR. Inhibition or induction of autophagy enhances PLB-induced apoptosis. There is crosstalk between PLB-induced apoptosis and autophagy. These findings indicate that PLB initiates both apoptosis and autophagy in NSCLC cells through coordinated pathways.

[Clinicopathological diagnosis of hypersensitivity pneumonitis].

OBJECTIVE: To enhance the understandings of clinical, radiological and pathological features of hypersensitivity pneumonitis (HP). METHODS: Six HP cases with pathological data, clinical and radiological data were retrospectively analyzed during the period from February 2009 to September 2011 at Beijing Hospital of Ministry of Health. There were 2 males and 4 females with a mean age of 51.5 years (range: 38-61). Clinically, the patients presented with chronic cough, shortness of breath and dyspnea (n = 2). The disease course was 1-8 months. Five cases had fed pigeons and other contact histories. Specimens obtained by transbronchial lung biopsy (n = 3) and open lung biopsy (n = 3) were paraffin embedded and stained by hematoxylin and eosin, special stains and immunohistochemistry. RESULTS: Four cases had subacute HP and 2 cases chronic HP. Three cases of subacute HP underwent transbronchial lung biopsy. One case of subacute HP and 2 cases of chronic HP were diagnosed by open lung biopsy. High-resolution computed tomography of lungs showed diffuse ground glass and patch shadow along the bronchial and centrilobular distributions. There was a predominance of upper half zone. Typical visible mosaic syndrome was present. There was poorly formed granuloma without cheesy necrosis. With an insidious medical history and complicated radiological features, chronic HP cases were characterized by pulmonary interstitial fibrosis. There were usual interstitial pneumonitis (UIP)-like fibrosis and fibrosis with an airway-centered distribution type. The lesions were distributed around bronchioles. Continuous bridge fibrosis might be present. There were bronchiolar metaplasia of peribronchiolar alveoli, poorly formed granuloma and multinucleated giant cells in interstitium. Schaumann body was identified in 1 case. CONCLUSIONS: Because of its diverse clinical, radiological and pathological features, HP may be easily confused with other interstitial lung diseases. Aggregate analyses yield a definite diagnosis.

[Clinicopathologic features of hepatic diabetic microangiopathy].

OBJECTIVE: To study the clinicopathological features of diabetic microangiopathy in liver and diabetic hepatosclerosis (DHS) of elderly male with type 2 diabetes mellitus (T2DM). METHODS: One hundred and twenty autopsy cases with T2DM (diabetic group) and contemporary 48 cases, non-diabetic and glucose tolerance abnormal, matched by gender and age (control group) were selected in the study. Cases with the cirrhosis and fibrosis of liver caused by other foregone etiological factors were excluded. The histopathological changes of microangiopathy in liver, hepatic portal areas and hepatic sinusoid were investigated by HE staining, histochemical and immunohistochemical stain methods. The clinical data of diagnostic DHS cases were analyzed. RESULTS: (1) Microangiopathy was observed in 54.2% (65/120) cases of diabetic group. Histological features: microangiopathy was found in interlobular arteries (especially in arteriole, the lumen diameter < 100 µm), which included endothelial denudation, eosinophilic material deposition in the tunica intima of artery, and eccentric intimal thickening. The smooth muscle fibers of tunica media were hyperplastic or atrophy. Fibroplasia and collagen deposition were found in the tunica adventitia of artery. Arterial lumina showed stenosis and occlusion. Microangiopathy was seen in 16.7% (8/48) cases of the control group. There was statistically significant difference between the two groups (χ(2) = 19.622, P < 0.01). (2) The fibrosis and sclerosis of portal areas were detected in 55.8% (67/120) cases of T2DM group. Hyaline collagen fiber tissues was deposited around interlobular arteries, interlobular veins and interlobular bile ducts, resulting in enlargement of the portal area and the secondary atrophy and disappearance of portal triad. The fibrosis and sclerosis of portal areas were detected in 22.9% (11/48) cases of the control group. There was a statistically significant difference between the two groups (χ(2) = 14.936, P < 0.01). (3) The pathological features of 14.2% (17/120) cases were consistent with the diagnosis of DHS. The fibrous tissue extended from fibrosis or sclerosis of portal areas, or eosinophilic material deposition in the hepatic sinusoid in non-zonal pattern. The results of histochemical staining showed collagen fiber deposition in hepatic sinusoid. Stainings for Collagen IV, SMA, CD34 were found in the hepatic sinusoid. The sclerosis of hepatic sinusoid was not detected in any case in the control group.Overall, 13/17 and 11/17 DHS cases had liver microangiopathy and portal areas sclerosis respectively. Diabetic nephropathy was seen in 10 of 17 DHS cases. Among the 17 cases, 7 cases showed ALP elevation, of which there were 3 cases with ALT and AST mild elevation. CONCLUSIONS: Diabetic microangiopathy is common in the liver of elderly men with T2DM. And DHS is associated with diabetic microangiopathy. Fibrosis and sclerosis of portal areas may be the early or concomitant changes of DHS on histological ground. DHS is one of the complications of T2DM.

Praeruptorin A inhibits lipopolysaccharide-induced inflammatory response in murine macrophages through inhibition of NF-κB pathway activation.

Praeruptorin A (PA) is a pyranocoumarin compound isolated from the dried root of Peucedanum praeruptorum Dunn (Umbelliferae). However, the antiinflammatory effect of PA has not been reported. The present study investigated the antiinflammatory effect of PA in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells. PA significantly inhibited the LPS-induced production of nitric oxide (NO), interleukin-1ß (IL-1ß) and tumor necrosis factor-α (TNF-α). The mRNA and protein expressions of inducible nitric oxide synthase (iNOS), IL-1ß and TNF-α were also suppressed by this compound. Further study showed that PA decreased the cytoplasmic loss of inhibitor κB-α (IκB-α) protein and inhibited the translocation of NF-κB from cytoplasm to nucleus. Taken together, the results suggest that PA may exert antiinflammatory effects in vitro in LPS-stimulated RAW 264.7 macrophages through inhibition of NF-κB signal pathway activation.

Effect of astragaloside IV on hepatic glucose-regulating enzymes in diabetic mice induced by a high-fat diet and streptozotocin.

AIM: Hepatic glycogen phosphorylase (GP) and glucose-6-phosphatase (G6Pase) are important in control of blood glucose homeostasis, and are considered to be potential targets for antidiabetic drugs. Astragaloside IV has been reported to have a hypoglycemic effect. However, the biochemical mechanisms by which astragaloside IV regulates hepatic glucose-metabolizing enzymes remain unknown. The present study examines whether GP and G6Pase mediate the hypoglycemic effect of astragaloside IV. METHODS: Type 2 diabetic mice were treated with astragaloside IV for 2 weeks. Blood glucose and insulin levels were measured by a glucometer and the ELISA method, respectively. Total cholesterol (TC) and triglyceride (TG) levels were determined using Labassay kits. Activities of hepatic GP and G6Pase were measured by the glucose-6-phosphate dehydrogenase-coupled reaction. The mRNA and protein levels of both enzymes were determined by real-time RT-PCR and Western blotting. RESULTS: Astragaloside IV at 25 and 50 mg/kg significally decreased the blood glucose, TG and insulin levels, and inhibited the mRNA and protein expression as well as enzyme activity of GP and G6Pase in diabetic mice. CONCLUSIONS: Astragaloside IV exhibited a hypoglycemic effect in diabetic mice. The hypoglycemic effect of this compound may be explained, in part, by its inhibition of hepatic GP and G6Pase activities.

[Construction of a bait plasmid containing human telomerase RNA mutant in yeast three-hybrid system].

OBJECTIVE: To construct a bait plasmid containing human telomerase RNA with multiple point mutations in a yeast three-hybrid system and evaluate the toxicity of the recombinant bait plasmid. METHODS: The primers were designed according to the hTR sequence and the target mutation sites for inducing T-->A mutations at the 41st, the 80th and 102nd nucleotides of the hTR gene using the overlapping extension PCR (OE-PCR) method. The mutant was cloned into PMD18T vector, confirmed by sequencing, sub-cloned into the bait plasmid PRH3' and identified with PCR and restriction enzyme digestion. The recombinant bait plasmid was then transformed into yeast L40 ura3/pHyblex/ZeoMS2 for toxicity test. RESULTS: Sequence analysis demonstrated successful introduction of point mutations at the target sites without causing random mutation. The recombined bait plasmid constructed showed no obvious toxicity against the host yeast cells. CONCLUSIONS: The recombinant plasmid containing the human telomerase RNA mutant (PRH3'-hTRm) has been successfully constructed and can be used as the bait plasmid in yeast three-hybrid system.