A novel DNase like compound that inhibits virus propagation from Asian Green Mussel, Perna viridis (Linn.).

Viral diseases are not only responsible for health related issues but also exert pressure on the State economy. Tropical and subtropical countries have more prevalence of virus associated pathological conditions such as chickenpox, adenovirus related infections, dengue, chickengunya, infectious mononucleosis, etc. Treatment options with effective antiviral drugs are limited and are unfortunately not free from undesirable effects. The Asian Green Mussel, Perna viridis (Linn.) (Mytilidae) are not only important for their evolutionary significance, high caloric index, ecological role in the sequestration of environmental pollutants especially heavy metals, but also are potential source for extraction of therapeutic and bioactive compounds. On the other hand, generally in bivalves, virus mediated mortality is not uncommon. In this study, we made a maiden attempt of exploring DNAse like bioactivity for natural non-protenacious compound(s) extracted from P. viridis. Crude Methanol Extract (CME) of soft tissue of P. viridis and subsequently its partially purified component (PPC) possess exceptional ability to degrade indiscriminately both low and high molecular weight DNAs. In vitro digestions for1, 2 and 3 h with CME and PPC were found to be comparable to commercial (Sigma-Aldrich) enzyme, DNase I. Bioactive assays conducted to evaluate antimicrobial property, have shown that CME and PPC exclusively inhibit viral propagation. Nonetheless, CME & PPC have no effect on the propagation of bacteria (0 mm ZOI). These results indicate the possibility of a source of potential antiviral drug against DNA Group I viruses. Although our study does not provide any data to correlate to any physiological functions of these substances but provides a clue towards an important role in the biology of mussels. Any conclusion at this stage is premature. However, taking into consideration the significantly high virus mediated mortality in bivalves and the antiviral bioactivity of these substances, it appears that mussels have evolved some mechanisms to counteract some viruses.

The effect of cinobufacini injection on DNA topoisomerase Ⅰ of human hepatocellular carcinoma HepG-2 cells / 中国癌症杂志

Background and purpose:The cinobufacini injection is a traditional antitumor drug.However,its mechanism iS still unclear.The purpose of this study was to observe the effect of cinobufacini injections in DNA TOPO Ⅰ of human hepatocellular carcinoma HcpG-2 cells.Methods:The cells that were proliferated were assessed by MTT assay.Cell cycles were shown through FCM.TOPO Ⅰ mRNA expression was analyzed through RT-PCR.The activity of TOPO Ⅰ was measured by TOPO Ⅰ mediated super coiled PHR322 relaxation.Supercoiled PBR322 was also used to determine the direct DNA breakages.Results:Cinobufacini injections significantly inhibited HepG-2 cells proliferation in ways that were dependent on dosages and time.Induced tumor cells arrest at the S-phase.TOPO ⅠmRNA expression decreased in a manner that was dependent on dosages which inhibited the TOPO Ⅰ mediated DNA relaxations.However,the cinobufacini injections could not directly induce DNA breakage at any concentration.Conclusion:Cinobufacini injections can inhibit human hepatocellular carcinoma HepG-2 cells proliferation.The regulation of topoisomerase Ⅰ activity and mRNA expression may be one of the mechanisms that causes the cinobufacini injection to contribute against tumor.

TSPO:new nomenclature for the peripheral benzodiazepine receptor and its role in the neuropsycopharmacology / 中国药理学通报

The early characterization of the diazepam-binding sites outside the brain led to their assignment as peripheralbenzodiazepine receptors, or PBRs, to distinguish them from the central benzodiazepine receptor.Although PBR is a widely used and accepted name in the scientific community,recent data regarding the structure and molecular function of this protein increasingly support renaming it to represent more accurately its subcellular role (or roles) and putative tissue-specific function (or functions). Translocator protein (18 ku,TSPO), is proposed as a new name, regardless of the subcellular localization of the protein. This review deals with the pharmacological, structural and molecular characterization of the PBR and its role in the neuropshcopharmacology.

A Convenient Radiolabeling of 11C(R)-PK11195 Using Loop Method in Automatic Synthesis Module / 핵의학분자영상

PURPOSE: ((R)-1-(2-chlorophenyl)-N-1-[11C]methyl-N-(1-propyl)-3-isoquinoline carboxamide ((R)-PK11195) is a specific ligand for the peripheral type benzodiazepine receptor and a marker of activated microglia, used to measure inflammation in neurologic disorders. We report here that a direct and simple radiosynthesis of [11C](R)-PK11195 inmild condition using NaH suspension in DMF and one-step loop method. MATERIALS AND METHODS: (R)-NDesmethyl- PK11195 (1 mg) in DMSO (0.1 mL) and NaH suspension in DMF (0.1 mL) were injected into a semi-prep HPLC loop. [11C]methyl iodide was passed through HPLC loop at room temperature. Purification was performed using semi-preparative HPLC. Aliquots eluted at 11.3 min were collected and analyzed by analytical HPLC and mass spectrometer. RESULTS: The labeling efficiency of [11C](R)-PK11195 was 71.8+/-8.5%. The specific activity was 11.8 +/-6.4 GBq/micromol and radiochemical purity was higher than 99.2%. The mass spectrum of the product eluted at 11.3 min showed m/z peaks at 353.1 (M+1), indicating the mass and structure of (R)-PK11195. CONCLUSION: By the one-step loop method with the [11C]CH3I automated synthesis module, [11C](R)-PK11195 could be easily prepared in high radiochemical yield using NaH suspension in DMF.

Apoptosis and Peripheral Benzodiazepin Receptor (PBR) Expression in Human Granulosa-Luteal Cells by GnRH-agonist / 대한불임학회지

OBJECTIVE: To investigate whether GnRH-agonist (GnRH-Ag) using in IVF-ET affects apoptosis of human granulosa-luteal cells and expression of peripheral benzodiazepine receptor (PBR) protein involved in the apoptosis of the cells. METHODS: Granulosa-luteal cells obtained during oocyte retrieval were cultured and treated with 10(-5) M GnRH-Ag. Apoptosis of the cells by the treatment was confirmed using DNA fragmentation analysis 24 h after culture. The presence of PBR protein within the cells was examined by immunofluorescence staining and the expression of the protein was analyzed by Western blotting. In addition, it was measured for progesterone and nitric oxide (NO) produced by granulosa-luteal cells after GnRH-Ag treatment. To evaluate the relationship between NO production and PBR expression, sodium nitroprusside (SNP) as a NO donor was added in media and investigated the expression of PBR protein by Western blotting. RESULTS: Apoptosis increased in the granulosa-luteal cells 24 h after GnRH-Ag treatment, whereas the expression of PBR protein significantly decreased. Furthermore, the production of progesterone and nitric oxide (NO) by the cells significantly fell from 12 h after the treatment. In the results of Western blotting after SNP treatment, the expression of PBR protein increased in the treatment with SNP alone to the granulosa-luteal cells, but was suppressed in the treatment with GnRH-Ag and SNP. Additionally, the staining result of PBR protein in the cells showed the even distribution of it through the cell. CONCLUSION: These results demonstrate that GnRH-Ag treatment induces apoptosis, decreasing expression of PBR protein and NO production in human granulosa-luteal cells. The present study suggests that one of the apoptosis mechanism of human granulosa-luteal cells by GnRH-Ag might be a signal transduction pathway via NO and PBR.

Changes of renal peripheral benzodiazepine receptor in the stress/anxiety response

Peripheral benzodiazepine receptor(PBR) has been identified in various peripheral tissues including kidney. The physiological and pharmacological functions of PBR are still uncertain, although it has been suggested that these are associated with the regulation of stress/anxiety response. Diazepam progeny, which were exposed to diazepam perinatally, was reported to be an animal model of chronic anxiety. However, PBR in the diazepam progenies are not known yet. In the present study, therefore, we examined the changes of PBR in the stress/anxiety response. Dams of rats were given injection of diazepam or vehicle during puerperium. Diazepam progenies showed increased level of anxiety on the performance of elevated plus maze, and increased Bmax of PBR. Saturation experiments followed by scatchard analysis of the results showed that the increase in the density of PBR and the affinity of the PBR remained unchanged. Forced swim stress increased anxiety on the plus maze in both groups of rats. In contrast to control, diazepam progenies did not show further upregulation of renal PBR immediately after swimming stress, but still higher than control. From the above results, it may be concluded that upregulation of renal PBR is associated with chronic anxiety as well as stress-induced response.

Isolation and characterization of cDNA clones for α- and β-subunits of ovine luteinizing hormone.

A cDNA library of ovine pituitary DNA in plasmid pBR322 has been constructed by conventional methods with certain modifications. The library was screened using partial cDNAs for rat α-subunit and LHβ. We have isolated cDNA clones for ovine α- subunit and LHβ. The identification of these clones was confirmed by partial sequencing. The clones bear about 80% sequence homology with the respective rat cDNAs in the sequenced regions and hybridize with the rat clones in 5 X SSC at 55°C. The ovine LHβ clone has an insert of about 650 bp and selects an RNA of about 750 bases in a northern blot. The α-subunit cDNA clone has an insert of about 550 bp; it has two internal Pst I sites and thus shows restriction-based differences from rat α-subunit cDNA, which does not have any Pst I site.

DNA binding proteins of rat thigh muscle: Purification and characterization of an endonuclease.

Two major DNA binding proteins of molecular weights 34,000 and 38,000 have been identified in the 30,000 g supernatant (S-30) fraction of rat thigh muscle extracts. The presence of 38 KD DNA binding protein in the muscle S-30 could be demonstrated only if Triton X-100 treated extracts were used for Afinity chromatography suggesting that this protein may be a membrane associated DNA binding protein. The 38 KD DNA binding protein differed from the 34 KD DNA binding protein also in its chromatographic behaviour in DE-52 columns in which the 38 KD protein was retained, while the 34 KD protein came out in the flow-through in an electrophoretically pure form. The 34 KD DNA binding protein can also be purified by precipitation with MgCl2. Incubation of 0·15 Μ NaCl eluates (containing the 38 KD and/or 34 KD DNA binding protein) in the presence of 100 mM Mg2+ resulted in the specific precipitation of the 34 KD protein. Prolonged incubation (30 days) of the 0·15 Μ NaCl eluates containing the two DNA binding proteins at 4°C led to the preferential degradation of the 34 KD DNA binding protein. Nitrocellulose filter binding assays indicated selective binding of purified 34 KD protein to ss DNA. Purified 34 KD DNA binding protein cleaved pBR 322 supercoiled DNA, and electrophoresis of the cleavage products in agarose gels revealed a major DNA band corresponding to the circular form of DNA.