Polycystic Kidney Disease in the Medaka (Oryzias latipes) pc Mutant Caused by a Mutation in the Gli-Similar3 (glis3) Gene

Polycystic kidney disease (PKD) is a common hereditary disease in humans. Recent studies have shown an increasing number of ciliary genes that are involved in the pathogenesis of PKD. In this study, the Gli-similar3 (glis3) gene was identified as the causal gene of the medaka pc mutant, a model of PKD. In the pc mutant, a transposon was found to be inserted into the fourth intron of the pc/glis3 gene, causing aberrant splicing of the pc/glis3 mRNA and thus a putatively truncated protein with a defective zinc finger domain. pc/glis3 mRNA is expressed in the epithelial cells of the renal tubules and ducts of the pronephros and mesonephros, and also in the pancreas. Antisense oligonucleotide-mediated knockdown of pc/glis3 resulted in cyst formation in the pronephric tubules of medaka fry. Although three other glis family members, glis1a, glis1b and glis2, were found in the medaka genome, none were expressed in the embryonic or larval kidney. In the pc mutant, the urine flow rate in the pronephros was significantly reduced, which was considered to be a direct cause of renal cyst formation. The cilia on the surface of the renal tubular epithelium were significantly shorter in the pc mutant than in wild-type, suggesting that shortened cilia resulted in a decrease in driving force and, in turn, a reduction in urine flow rate. Most importantly, EGFP-tagged pc/glis3 protein localized in primary cilia as well as in the nucleus when expressed in mouse renal epithelial cells, indicating a strong connection between pc/glis3 and ciliary function. Unlike human patients with GLIS3 mutations, the medaka pc mutant shows none of the symptoms of a pancreatic phenotype, such as impaired insulin expression and/or diabetes, suggesting that the pc mutant may be suitable for use as a kidney-specific model for human GLIS3 patients.     

RNA Editing Genes Associated with Extreme Old Age in Humans and with Lifespan in C. elegans

Background

The strong familiality of living to extreme ages suggests that human longevity is genetically regulated. The majority of genes found thus far to be associated with longevity primarily function in lipoprotein metabolism and insulin/IGF-1 signaling. There are likely many more genetic modifiers of human longevity that remain to be discovered.

Methodology/Principal Findings

Here, we first show that 18 single nucleotide polymorphisms (SNPs) in the RNA editing genes ADARB1 and ADARB2 are associated with extreme old age in a U.S. based study of centenarians, the New England Centenarian Study. We describe replications of these findings in three independently conducted centenarian studies with different genetic backgrounds (Italian, Ashkenazi Jewish and Japanese) that collectively support an association of ADARB1 and ADARB2 with longevity. Some SNPs in ADARB2 replicate consistently in the four populations and suggest a strong effect that is independent of the different genetic backgrounds and environments. To evaluate the functional association of these genes with lifespan, we demonstrate that inactivation of their orthologues adr-1 and adr-2 in C. elegans reduces median survival by 50%. We further demonstrate that inactivation of the argonaute gene, rde-1, a critical regulator of RNA interference, completely restores lifespan to normal levels in the context of adr-1 and adr-2 loss of function.

Conclusions/Significance

Our results suggest that RNA editors may be an important regulator of aging in humans and that, when evaluated in C. elegans, this pathway may interact with the RNA interference machinery to regulate lifespan.     

Characterization and Application of a New Monoclonal Antibody with High Specificity for Helicobacter hepaticus

Background and Aims:  Infection with Helicobacter hepaticus is suggested to play a role in the pathogenesis of chronic liver disease in humans. However, reactive antigens among Helicobacter species make the development of an H. hepaticus ELISA test with high specificity difficult. A new monoclonal antibody from a hybridoma clone (HRII-51) showed high specificity to H. hepaticus without cross-reaction to other gastrointestinal bacteria.
Methods:  The molecular weight of HRII-51 immunoreactive antigen was examined by Western blot of H. hepaticus probed with the monoclonal antibody HRII-51. A HRII-51-immunoreactive antigen capture ELISA was prepared in which the specific antigen was anchored by HRII-51-immobilized ELISA plate. Accuracy of HRII-51 antigen capture ELISA was examined using sera obtained from mice inoculated with Helicobacter species. Specificity of HRII-51 antigen capture ELISA was compared to that of H. hepaticus antigen-based ELISA using human sera with absorption by H. pylori cell lysate.
Results:  HRII-51 immunoreactive antigen had a molecular weight of 15 kDa. Sensitivity and specificity of HRII-51 antigen capture ELISA were 87.0% and 97.6% in mice inoculated with Helicobacter species. In human sera, modification of the results by absorption with H. pylori lysate was smaller in HRII-51 antigen capture ELISA comparing with H. hepaticus -antigen-based ELISA.
Conclusion:  Use of the HRII-51 antigen capture ELISA would be a useful approach for the serodiagnosis of H. hepaticus infection in both experimental animals and humans.     

Towards the Understanding of Complex Traits in Rice: Substantially or Superficially?

Completion of the genome analysis followed by extensive comprehensive studies on a variety of genes and gene families of rice (Oryza sativa) resulted in rapid accumulation of information concerning the presence of many complex traits that are governed by a number of genes of distinct functions in this most important crop cultivated worldwide. The genetic and molecular biological dissection of many important rice phenotypes has contributed to our understanding of the complex nature of the genetic control with respect to these phenotypes. However, in spite of the considerable advances made in the field, details of genetic control remain largely unsolved, thereby hampering our exploitation of this useful information in the breeding of new rice cultivars. To further strengthen the field application of the genome science data of rice obtained so far, we need to develop more powerful genomics-assisted methods for rice breeding based on information derived from various quantitative trait loci (QTL) and related analyses. In this review, we describe recent progresses and outcomes in rice QTL analyses, problems associated with the application of the technology to rice breeding and their implications for the genetic study of other crops along with future perspectives of the relevant fields.Key words: QTL, near-isogenic lines, chromosome segment substitution lines, marker-assisted selection, map-based cloning     

Diversity of hydrocarbon-degrading Klebsiella strains isolated from hydrocarbon-contaminated estuaries

Aims:  To investigate the diversity and the catabolic capacity of oil-degrading Klebsiella strains isolated from hydrocarbon-contaminated sediments in Santos–São Vicente estuary systems in Brazil.
Methods and Results:  Klebsiella strains obtained from the estuary were characterized using 16S rRNA gene sequencing and BOX-PCR patterns, testing their catabolic capacity to degrade toluene, xylene, naphthalene and nonane, and identifying the catabolic genes present in the oil-degrading strains. Results show that Klebsiella strains were widespread in the estuary. Twenty-one isolates from the Klebsiella genus were obtained; 14 had unique BOX patterns and were further investigated. Among four distinct catabolic genes tested ( todC 1, ndoB , xylE and alkB 1), only the todC 1 gene could be amplified in two Klebsiella strains. The biodegradation assay showed that most of the strains had the ability to degrade all of the tested hydrocarbons; however, the strains displayed different efficiencies.
Conclusions:  The oil-degrading Klebsiella isolates obtained from the estuary were closely related to Klebsiella pneumoniae and Klebsiella ornithinolytica . The isolates demonstrated a substantial degree of catabolic plasticity for hydrocarbon degradation.
Significance and Impact of the Study:  The results of this study show that several strains from the Klebsiella genus are able to degrade diverse hydrocarbon compounds. These findings indicate that Klebsiella spp. can be an important part of the oil-degrading microbial community in estuarine areas exposed to sewage.     

Phenylethanoid oligoglycosides and acylated oligosugars with vasorelaxant activity from Cistanche tubulosa

The methanolic extract from the dried stems of Cistanche tubulosa (Schrenk) R. Wight was found to show an inhibitory effect on contractions induced by noradrenaline in isolated rat aortic strips. From the extract, new phenylethanoid oligoglycoside constituents, kankanosides F and G, and an acylated oligosugar, kankanose, were isolated together with 14 known compounds. The structures of these new compounds were determined on the basis of their chemical and physicochemical evidence. In addition, principal constituents, kankanoside F, kankanose, echinacoside, acteoside, and cistanoside F, showed vasorelaxant activity, and several structural requirements for the activity were clarified.     

Synthesis, SAR studies, and evaluation of 1,4-benzoxazepine derivatives as selective 5-HT1A receptor agonists with neuroprotective effect: Discovery of Piclozotan

A new series of 1,4-benzoxazepine derivatives was designed, synthesized, and evaluated for binding to 5-HT1A receptor and cerebral anti-ischemic effect. A lot of compounds exhibited nanomolar affinity for 5-HT1A receptor with good selectivity over both dopamine D2 and alpha1-adrenergic receptors. Among these compounds, 3-chloro-4-[4-[4-(2-pyridinyl)-1,2,3,6-tetrahydropyridin-1-yl]butyl]-1, 4-benzoxazepin-5(4H)-one (50: SUN N4057 (Piclozotan) as 2HCl salt) showed remarkable neuroprotective activity in a transient middle cerebral artery occlusion (t-MCAO) model.     

Inhibitory effects of coumarin and acetylene constituents from the roots of Angelica furcijuga on D-galactosamine/lipopolysaccharide-induced liver injury in mice and on nitric oxide production in lipopolysaccharide-activated mouse peritoneal macrophages

The methanolic extract (200 mg/kg, p.o. and i.p.), principal coumarin constituents (isoepoxypteryxin, anomalin, and praeroside IV), and a polyacetylene constituent (falcarindiol) (25 mg/kg, i.p.) from the roots of Angelica furcijuga protected the liver injury induced by D-galactosamine (D-GalN)/lipopolysaccharide (LPS) in mice. In in vitro experiments, coumarin constituents (hyuganins A-D, anomalin, pteryxin, isopteryxin, and suksdorfin) and polyacetylene constituents [(-)-falcarinol and falcarindiol] substantially inhibited LPS-induced NO and/or TNF-alpha production in mouse peritoneal macrophages, and isoepoxypteryxin inhibited D-GalN-induced cytotoxicity in primary cultured rat hepatocytes. Furthermore, hyuganin A, anomalin, and isopteryxin inhibited the decrease in cell viability by TNF-alpha in L929 cells.     

Molecular mechanism for the regulation of rho-kinase by dimerization and its inhibition by fasudil

Rho-kinase is a key regulator of cytoskeletal events and a promising drug target in the treatment of vascular diseases and neurological disorders. Unlike other protein kinases, Rho-kinase requires both N- and C-terminal extension segments outside the kinase domain for activity, although the details of this requirement have been elusive. The crystal structure of an active Rho-kinase fragment containing the kinase domain and both the extensions revealed a head-to-head homodimer through the N-terminal extension forming a helix bundle that structurally integrates the C-terminal extension. This structural organization enables binding of the C-terminal hydrophobic motif to the N-terminal lobe, which defines the correct disposition of helix alphaC that is important for the catalytic activity. The bound inhibitor fasudil significantly alters the conformation and, consequently, the mode of interaction with the catalytic cleft that contains local structural changes. Thus, both kinase and drug conformational pliability and stability confer selectivity.