Engineering a gene silencing viral construct that targets the cat hypothalamus to induce permanent sterility: An update.

The intent of this contribution is to provide an update of the progress we have made towards developing a method/treatment to permanently sterilize cats. Our approach employs two complementary methodologies: RNA interference (RNAi) to silence genes involved in the central control of reproduction and a virus-based gene therapy system intended to deliver RNAi selectively to the hypothalamus (where these genes are expressed) via the systemic administration of modified viruses. We selected the hypothalamus because it contains neurons expressing Kiss1 and Tac3, two genes essential for reproduction and fertility. We chose the non-pathogenic adeno-associated virus (AAV) as a vector whose tropism could be modified to target the hypothalamus. The issues that must be overcome to utilize this vector as a delivery vehicle to induce sterility include modification of the wild-type AAV to target the hypothalamic region of the brain with a simultaneous reduction in targeting of peripheral tissues and non-hypothalamic brain regions, identification of RNAi targets that will effectively reduce the expression of Kiss1 and Tac3 without off-target effects, and determination if neutralizing antibodies to the AAV serotype of choice are present in cats. Successful resolution of these issues will pave the way for the development of a powerful tool to induce the permanent sterility in cats.

Analysis of rotavirus antigenemia in hematopoietic stem cell transplant recipients.

Systemic rotavirus infection, such as rotavirus antigenemia, has been found in immunocompetent rotavirus gastroenteritis patients. However, the pathogenesis of rotavirus infection in immunocompromised transplant recipients remains unclear. Enzyme-linked immunosorbent assay was used to measure rotavirus antigen levels in serially collected serum samples obtained from 62 pediatric patients receiving allogeneic hematopoietic stem cell transplants (HSCT). Rotavirus antigen was detected in 43 (6.8%) of 633 serum samples (8 of 62 patients). The duration of rotavirus antigenemia ranged between 1 and 10 weeks, and diarrhea was concurrent with rotavirus antigenemia in Cases 3, 6, 7, and 8. The level of viral antigen in the transplant recipients (0.19 ± 0.20) was significantly lower than that observed in serum samples collected from immunocompetent patients on either day 1 (0.49 ± 0.18, P = 0.0011) or day 3 (0.63 ± 0.09, P = 0.0005). A patient who received a graft from a human leukocyte antigen (HLA)-mismatched donor was at significant risk for rotavirus antigenemia (P = 0.024; odds ratio = 9.44) in comparison to patients who received grafts from HLA-matched donors. Although the duration of antigenemia was clearly longer in HSCT patients than in immunocompetent rotavirus gastroenteritis patients, the levels of viral antigen were not as high. Therefore, mismatched HLA may be a risk factor for rotavirus antigenemia after HSCT.

Sustained survival of human hepatocytes in mice: A model for in vivo infection with human hepatitis B and hepatitis delta viruses.

Persistence of hepatocytes transplanted into the same or related species has been established. The long-term engraftment of human hepatocytes into rodents would be useful for the study of human viral hepatitis, where it might allow the species, technical and size limitations of the current animal models to be overcome. Although transgenic mice expressing the hepatitis B virus (HBV) genome produce infectious virus in their serum, the viral life cycle is not complete, in that the early stages of viral binding and entry into hepatocytes and production of an episomal transcriptional DNA template do not occur. As for hepatitis delta virus (HDV), another cause of liver disease, no effective therapy exists to eradicate infection, and it remains resistant even to recent regimens that have considerably changed the treatment of HBV (ref. 13). Here, we demonstrate long-term engraftment of primary human hepatocytes transplanted in a matrix under the kidney capsule of mice with administration of an agonistic antibody against c-Met. These mice were susceptible to HBV infection and completion of the viral life cycle. In addition, we demonstrate super-infection of the HBV-infected mice with HDV. Our results describe a new xenotransplant model that allows study of multiple aspects of human hepatitis viral infections, and may enhance studies of human liver diseases.

Effects of irradiating adult mdx mice before full-length dystrophin cDNA transfer on host anti-dystrophin immunity.

Duchenne muscular dystrophy is a fatal, genetic disorder in which dystrophin-deficient muscle progressively degenerates, for which dystrophin gene transfer could provide effective treatment. The host immune response to dystrophin, however, is an obstacle to therapeutic gene expression. Understanding the dystrophin-induced host immune response will facilitate the discovery of strategies to prolong expression of recombinant dystrophin in dystrophic muscle. Using whole-body irradiation of the dystrophic mdx mouse before gene transfer, we temporally removed the immune system; a 600 rad dose removed peripheral immune cells, which were restored by self-reconstitution, and a 900 rad dose removed central and peripheral immune cells, which were restored by adoptive transfer of bone marrow from a syngeneic, dystrophin-normal donor. The anti-dystrophin humoral response was delayed and dystrophin expression was partially preserved in irradiated, vector-treated mice. Nonirradiated, vector-treated control mice lost muscle dystrophin expression completely, had an earlier anti-dystrophin humoral response and demonstrated muscle fibers focally surrounded with T cells. We conclude that dystrophin gene transfer induced anti-dystrophin humoral immunity and cell-mediated responses that were significantly diminished and delayed by temporal removal of the host central or peripheral immune cells. Furthermore, manipulation of central immunity altered the pattern of regulatory T cells in muscle.

Human apolipoprotein B: structure of carboxyl-terminal domains, sites of gene expression, and chromosomal localization.

Apolipoprotein (apo-) B is the ligand responsible for the receptor-mediated catabolism of low density lipoproteins, the principal cholesterol-transporting lipoproteins in plasma. The primary structure of the carboxyl-terminal 30 percent (1455 amino acids) of human apo-B (apo-B100) has been deduced from the nucleotide sequence of complementary DNA. Portions of the protein structure that may relate to its receptor binding function and lipid binding properties have been identified. The apo-B100 messenger RNA is about 19 kilobases in length. The apo-B100 gene is expressed primarily in liver and, to a lesser extent, in small intestine, but in no other tissues. The gene for apo-B100 is located in the p24 region (near the tip of the short arm) of chromosome 2.

Detection of antilymphocyte antibody with two-color method in systemic lupus erythematosus and its heterogeneous specificities against human T-cell subsets.

The two-color method originally described by Van Rood et al. (Van Rood, J. J., A. Van Leeuwen, and J. S. Ploen. 1976. Simultaneous detection of two cell populations by two-color fluorescence and application to the recognition of B-cell determinants. Nature (Lond.). 262: 795-797) for the typing of homologous leukocytic antibodies, D-region was used for the detection of antilymphocyte antibody (ALA) in systemic lupus erythematosus. In this method, surface immunoglobulin-bearing cells were identified with fluorescein isothiocyanate-labeled anti-immunoglobulin and nuclei of killed cells were stained with ethidium bromide. Therefore, cell type (T or B) of the target cells can be identified without fractionating them. ALA was detected in 87% of lupus sera and had a preferential reactivity with T cells. Its major immunoglobulin class was shown to be immunoglobulin (Ig)M. The subspecificity of ALA was further analyzed using fractionated T-cell subsets as target cells. When T lymphocytes were separated into Fc receptor-bearing (Tgamma) and lacking (Tgamma[-]) cells, 64% of ALA showed preferential reactivity with Tgamma cells and 14% with Tgamma(-) cells. The remainder had no selective reactivity against Tgamma or Tgamma(-) cells. Tgamma cells were shown to have suppressor activity, whereas Tgamma(-) cells were indicated to contain helper cells. The above finding was in agreement with the observation that treatment of T cells with ALA that preferentially react with Tgamma cells considerably enhanced immunoglobulin synthesis in vitro, whereas treatment of T cells with ALA reactive with Tgamma(-) cells clearly suppressed the formation of immunoglobulins. Treatment of ALA with no selective reactivity showed variable effects on in vitro immunoglobulin synthesis. These results indicate that ALA in lupus have heterogeneous specificities against human T-cell subsets.

Increasing the size of rAAV-mediated expression cassettes in vivo by intermolecular joining of two complementary vectors.

A major shortcoming to the use of adeno-associated virus (rAAV) vectors is their limited packaging size. To overcome this hurdle, we split an expression cassette and cloned it into two separate vectors. The vectors contained either a nuclear localizing Escherichia coli lacZ transgene (nlslacZ) with a splice acceptor, or the human elongation factor 1alpha ( EF1alpha) gene enhancer/promoter(s) (EF1alphaEP) with a splice donor. We co-injected a promoter-less nlslacZ vector with a vector containing either a single EF1alphaEP or a double copy of the EF1alphaEP in a head-to-head orientation, into the portal vein of mice. Gene expression, measured by both transduction efficiency and quantitation of the recombinant protein, was as much as 60-70% of that obtained from mice that received a single vector containing a complete EFalphaEP/nlslacZ expression cassette. This two-vector approach may allow development of gene therapy strategies that will carry exogenous DNA sequences with large therapeutic cDNAs and/or regulatory elements.

[Malignant pleural mesothelioma].

Malignant pleural mesothelioma carries a poor prognosis, for which no standard therapy has been established. We report 15 cases of malignant pleural mesothelioma experienced since 2000 focusing on their clinical features. They included 14 male and 1 female aged 38 to 81 (62.8 on average) years. All patients were diagnosed by pleural biopsy under thoracoscopic guidance. Histology of the pleural biopsy specimen showed epithelial mesothelioma in 8 patients, biphasic mesothelioma in 3, sarcomatous mesothelioma in 2 and desmoplastic malignant mesothelioma (DMM) in 2. Twelve patients received chemotherapy. Of these, 3 were followed by surgery. In addition to 2 of these 3 patients, 2 underwent extrapleural pneumonectomy (EPP) without adjuvant treatment. Remaining 1 received palliative treatment only. As a result, 6 patients are surviving, 7 died of primary diseases and 2 died of other diseases. The longest survival time with chemotherapy is 41 months in a surviving patient with epithelial mesothelioma and that with EPP is 25 months in a surviving patient with DMM. The 2-year survival rate of the 14 patients was 44.4% and the median survival time in patients with epithelial mesothelioma was 30.6 months.

Electrocatalytic synthesis of ammonia by surface proton hopping.

Highly efficient ammonia synthesis at a low temperature is desirable for future energy and material sources. We accomplished efficient electrocatalytic low-temperature ammonia synthesis with the highest yield ever reported. The maximum ammonia synthesis rate was 30 099 µmol gcat-1 h-1 over a 9.9 wt% Cs/5.0 wt% Ru/SrZrO3 catalyst, which is a very high rate. Proton hopping on the surface of the heterogeneous catalyst played an important role in the reaction, revealed by in situ IR measurements. Hopping protons activate N2 even at low temperatures, and they moderate the harsh reaction condition requirements. Application of an electric field to the catalyst resulted in a drastic decrease in the apparent activation energy from 121 kJ mol-1 to 37 kJ mol-1. N2 dissociative adsorption is markedly promoted by the application of the electric field, as evidenced by DFT calculations. The process described herein opens the door for small-scale, on-demand ammonia synthesis.

Next-generation sequencing for patients with non-obstructive azoospermia: implications for significant roles of monogenic/oligogenic mutations.

Azoospermia affects up to 1% of adult men. Non-obstructive azoospermia is a multifactorial disorder whose molecular basis remains largely unknown. To date, mutations in several genes and multiple submicroscopic copy-number variations (CNVs) have been identified in patients with non-obstructive azoospermia. The aim of this study was to clarify the contribution of nucleotide substitutions in known causative genes and submicroscopic CNVs in the genome to the development of non-obstructive azoospermia. To this end, we conducted sequence analysis of 25 known disease-associated genes using next-generation sequencing and genome-wide copy-number analysis using array-based comparative genomic hybridization. We studied 40 Japanese patients with idiopathic non-obstructive azoospermia. Functional significance of molecular alterations was assessed by in silico analyses. As a result, we identified four putative pathogenic mutations, four rare polymorphisms possibly associated with disease risk, and four probable neutral variants in 10 patients. These sequence alterations included a heterozygous splice site mutation in SOHLH1 and a hemizygous missense substitution in TEX11, which have been reported as causes of non-obstructive azoospermia. Copy-number analysis detected five X chromosomal or autosomal CNVs of unknown clinical significance, in addition to one known pathogenic Y chromosomal microduplication. Five patients carried multiple molecular alterations. The results indicate that monogenic and oligogenic mutations, including those in SOHLH1 and TEX11, account for more than 10% of cases of idiopathic non-obstructive azoospermia. Furthermore, this study suggests possible contributions of substitutions in various genes as well as submicroscopic CNVs on the X chromosome and autosomes to non-obstructive azoospermia, which require further validation.

Frequent p53 gene mutations in blast crisis of chronic myelogenous leukemia, especially in myeloid crisis harboring loss of a chromosome 17p.

We investigated chromosome alterations and mutations of the p53 gene in 118 samples from 92 patients with chronic myelogenous leukemia in various clinical phases, i.e., chronic phase, accelerated phase, and blast crisis (BC). Single-strand conformation polymorphism analysis and subsequent nucleotide sequencing disclosed no alteration of the p53 gene in chronic phase (no mutation in 80 samples), while five of 31 BC samples showed point mutations: four in myeloid and one in lymphoid crisis. One of seven accelerated phase samples also showed a p53 gene mutation. Ten of 31 BC samples showed loss of one of the short arms of chromosome 17 (17p) through the formation of isochromosome 17q, i(17q), or unbalanced translocations. Loss of heterozygosity at the p53 locus in the accelerated phase and BC was detected only in two cases with i(17q) but not in seven cases with normal chromosome 17 homologues, suggesting that loss of one p53 allele is rare without cytogenetically detectable loss of a 17p. Among those six samples with p53 gene mutations, five showed loss of a 17p cytogenetically, and only one lymphoid crisis case exhibited normal chromosome 17 homologues. Thus, mutations of the p53 gene were closely associated with myeloid crisis with loss of a 17p (four mutations in ten samples), in contrast to myeloid crisis with normal chromosome 17 homologues (zero in 13) or lymphoid crisis (one in seven). Our results also suggest that alterations of the p53 gene might occur after loss of a 17p during the course of chronic myelogenous leukemia.

Two chromosomal locations for human ornithine decarboxylase gene sequences and elevated expression in colorectal neoplasia.

The polyamines are known to be essential for cellular proliferation. Ornithine decarboxylase (ODC) is a rate-limiting enzyme in the synthesis of these amines, and activity is elevated in colorectal tumors and polyps. Two ODC genes (designated ODC1 and ODC2) were localized by somatic cell hybridization and in situ techniques to 2p25 and 7q31-qter, respectively. Investigation of the expression of ODC in colorectal neoplasia reveals a consistent increase in mRNA expression compared with normal adjacent mucosa and control mucosa, ranging from 1.3- to 12.2-fold. No amplification of the loci was seen. Comparison of ODC mRNA expression with ODC activity from the same samples revealed no direct correlation, suggesting that regulation of ODC in this system occurs at the posttranscriptional level.

Determinant factors of postoperative recurrence of endometriosis: difference between endometrioma and pain.

OBJECTIVE: Although the postoperative use of hormonal treatment for endometriosis is recommended in the European Society of Human Reproduction and Embryology guidelines to prevent the recurrence of endometriosis-associated dysmenorrhoea, hormonal treatment may not be necessary for all patients who undergo surgical treatment for endometriosis. The aim of this study was to clarify the determinant factors that predict the recurrence of endometriosis after surgery in order to develop personalized hormonal treatment recommendations. Factors associated with the recurrence of endometrioma and pain were investigated independently to identify the likelihood of recurrence in each individual patient. STUDY DESIGN: Between 2008 and 2013, 352 patients underwent surgery and were diagnosed with endometriosis based on pathological findings at the study hospital. Among these patients, 191 experienced a recurrence of endometrioma in the absence of pre- or postoperative hormonal treatment. Various clinical factors such as pre-operative pain, intra-operative findings and postoperative improvement of pain were compared between patients who experienced recurrence after surgery and those who did not. RESULTS: The cumulative 5-year recurrence rate of endometrioma was 28.7% among the 191 patients who did not undergo pre- or postoperative hormonal treatment. Significant differences were detected in maximum tumour diameter, revised American Society for Reproductive Medicine score (r-ASRM score), operative time and operative blood loss between patients in the recurrent endometrioma group and the non-recurrent endometrioma group; only the r-ASRM score was significantly correlated with recurrence of endometrioma in the multivariate analysis. The cumulative 5-year rate of persistent/recurrent pain was 33.4%. There were significant differences in the postoperative improvement of pain between the persistent/recurrent pain group and the non-recurrent pain group according to the univariate and multivariate analyses. CONCLUSION: This study suggests that the risk factors for recurrence of endometrioma differ from the risk factors for recurrence of pain. The use of postoperative hormonal treatment should be considered based on the dominant risk factors and needs of each patient.

Duplex opening by primosome protein PriA for replisome assembly on a recombination intermediate.

PriA and other primosome assembly proteins of Escherichia coli recruit the major replicative helicase DnaB for replisome assembly during bacteriophage Mu transposition and replication. MuA transposase catalyzes the transfer of Mu ends to target DNA, forming a potential replication fork that provides the assembly site for the replisome. However, this fork lacks the single-stranded DNA needed to load DnaB. Although no pre-existing primosome assembly sites that bind PriA were found within the Mu end sequences, PriA was able to bind to the forked DNA structure created by MuA. The helicase activity of PriA could then open the duplex to create the DnaB binding site. In a tightly coupled reaction on synthetic forked substrates, PriA promoted both the unwinding of the lagging strand arm and preprimosome assembly to load DnaB onto the lagging strand template. PriA apparently translocated 3' to 5' along the lagging strand template until sufficient single-stranded DNA was exposed for binding of DnaB, which then translocated 5' to 3' in the opposite direction. Mutant PriA lacking helicase activity was unable to promote this process, and loss of PriA helicase impaired Mu DNA replication in vivo and in vitro. This suggests that the opening of the duplex by PriA helicase is a critical step in the initiation of Mu DNA replication. Concerted helicase and primosome assembly functions would allow PriA to act as initiator on recombination intermediates and stalled replication forks. As part of the replisome, PriA may act as a mobile initiator that minimizes interruptions in chromosomal replication.

Escherichia coli PriA helicase: fork binding orients the helicase to unwind the lagging strand side of arrested replication forks.

Escherichia coli PriA is a primosome assembly protein with 3' to 5' helicase activity whose apparent function is to promote resumption of DNA synthesis following replication-fork arrest. Here, we describe how initiation of helicase activity on DNA forks is influenced by both fork structure and by single-strand DNA-binding protein. PriA could recognize and unwind forked substrates where one or both arms were primarily duplex, and PriA required a small (two bases or larger) single-stranded gap at the fork in order to initiate unwinding. The helicase was most active on substrates with a duplex lagging-strand arm and a single-stranded leading-strand arm. On this substrate, PriA was capable of translocating on either the leading or lagging strands to unwind the duplex ahead of the fork or the lagging-strand duplex, respectively. Fork-specific binding apparently orients the helicase domain to unwind the lagging-strand duplex. Binding of single-strand-binding protein to forked templates could inhibit unwinding of the duplex ahead of the fork but not unwinding of the lagging-strand duplex or translocation on the lagging-strand template. While single-strand-binding protein could inhibit binding of PriA to the minimal, unforked DNA substrates, it could not inhibit PriA binding to forked substrates. In the cell, single-strand-binding protein and fork structure may direct PriA helicase to translocate along the lagging-strand template of forked structures such that the primosome is specifically assembled on that DNA strand.

Communication of ClpXP protease hypersensitivity to bacteriophage Mu repressor isoforms.

The immunity repressor (Rep) of bacteriophage Mu establishes and maintains lysogeny by shutting down transposition functions needed for phage DNA replication. Although Rep is stable in vivo, an altered immunity repressor (Vir) encoded by virulent, trans-dominant Mu mutants is rapidly degraded by Escherichia coli ClpXP protease. Rep and Vir are degraded at approximately the same maximal velocity (Vmax) by ClpXP, but the Km for Rep (3.6 microM) is over 20-fold higher than the Km for Vir (0.15 microM). Rep is also highly resistant to degradation in the presence of DNA whereas Vir is not. Vir increases the rate of Rep degradation by reducing its Km and imparts to Rep ClpXP sensitivity in the presence of DNA. Vir can drive at an accelerated rate the complete degradation of Rep molecules that outnumber Vir by eightfold or more. So long as Vir is present at a concentration of 0.1 microM or higher, Rep is degraded with a Km that is indistinguishable from that of Vir. These characteristics of repressor may be an important means of transducing physiological signals that induce Mu transposition in response to growth conditions or environmental stress, ClpXP hypersensitivity being disseminated among Rep molecules for the induction of Mu transposition.

Conformational dynamics of a transposition repressor in modulating DNA binding.

The repressor of bacteriophage Mu functions in the establishment and maintenance of lysogeny by binding to Mu operator DNA to shut down transposition. A domain at its N terminus functions in DNA binding, and temperature-sensitive mutations in this domain can be suppressed by truncations at the C terminus. To understand the role of the C-terminal tail in DNA binding, a fluorescent probe was attached to the C terminus to examine its environment and its movement with respect to the DNA binding domain. The emission spectrum of this probe indicated that the C terminus was in a relatively hydrophobic environment, comparable to the environment of the probe attached within the DNA-binding domain. Fluorescence of two tryptophan residues located within the DNA-binding domain was quenched by the probe attached to the C terminus, indicating that the C terminus is in close proximity to this domain. Addition of DNA, even when it did not contain operator DNA, reduced quenching of tryptophan fluorescence, indicating that the tail moves away from the DNA-binding domain as it interacts with DNA. The presence of the tail also produced a trypsin hypersensitive site within the DNA-binding domain; mutant repressors with an altered or truncated C terminus were relatively resistant to cleavage at this site. Interaction of the wild-type repressor with DNA greatly reduced cleavage at the site. A repressor with a temperature-sensitive mutation in the DNA-binding domain was especially sensitive to cleavage by trypsin even in the presence of DNA, and the C-terminal tail failed to move in the presence of DNA at elevated temperatures. These results indicate that the tail sterically inhibits DNA binding and that it moves during establishment of repression. Such conformational changes are likely to be involved in communication between repressor protomers for cooperative DNA binding.

N-ras mutation and karyotypic evolution are closely associated with leukemic transformation in myelodysplastic syndrome.

We performed a longitudinal analysis of the karyotypes and N-ras gene configuration of bone marrow cells in 35 patients with myelodysplastic syndrome (MDS). Karyotypic evolution was found in eight patients, and was associated with disease progression, including leukemic transformation, in all the patients. We identified N-ras mutations in six patients, using a polymerase chain reaction (PCR) technique, in which oligonucleotide primers were constructed with induced mismatches, followed by endonuclease digestion. Direct sequencing confirmed single base substitutions at codon 12 in two patients and at codon 13 in four. The incidence of N-ras gene mutations was significantly higher in the karyotypically evolved group (five of eight patients) than in the stable group (one of 27 patients). All of five patients harboring both karyotypic evolution and an N-ras mutation showed concomitant disease progression to overt leukemia or refractory anemia with excess of blasts in transformation (RAEB-T). Two of four patients with either karyotypic evolution or N-ras mutation and six of 26 patients without any of these alterations also progressed to overt leukemia. Our results indicate that the accumulation of these genetic alterations is closely associated with leukemic transformation of MDS, although other genetic alterations may also play a key role in the remaining patients.

Analysis of mutations and expression of GAP-related domain of the neurofibromatosis type 1 (NF1) gene in the progression of chronic myelogenous leukemia.

We investigated mutations in the GTPase activating protein-related domain of the neurofibromatosis type 1 gene (NF1-GRD) and its expression in each phase of chronic myelogenous leukemia (CML). Samples from 45 cases in chronic phase (CP), 41 in acute phase, and four CML cell lines were examined for mutations in the NF1-GRD by single-strand conformation polymorphism (SSCP) analysis and allele specific restriction analysis (ASRA). No mutations were detected in the exon where frequent mutations have recently been reported in human tumors, namely the FLR exon. We also examined for point mutations of the N-ras gene but found no mutations either. In 23 samples from CML cases and four CML cell lines, expression of two types of the NF1-GRD transcripts, type I and type II, were examined by NF1-GRD-specific polymerase chain reaction-based densitometric analysis and by the quantitative assay with coamplification of the NF1-GRD and beta-actin transcripts. Consequently, although expression level of type I transcripts varied among the samples, type II expression was increased in CML cell lines and a minor increase in type II expression was observed in the samples in acute phase compared with CP. However, this difference in type II expression between CP and acute phase was so small that changes of NF1-GRD transcripts as well as NF1-GRD or N-ras mutations might not be responsible for the progression of CML.