Cloning and Characterization of the Genomic RNA Sequence of the Mumps Virus Strain Associated with a High Incidence of Aseptic Meningitis

cDNA clones of the mumps virus wild-type strain, associated with a high incidence of aseptic meningitis (ODATE-1 strain), were isolated and analyzed from genomic nucleotide position 22 to 8520 containing the NP, P, M., F, SH and HN protein coding region. The ODATE-1 strain exhibited a RFLP profile identical to that of the Urabe vaccine strain in spite of the fact that the virus was isolated from non-vaccinated cases. However, a comparison of nucleotide and amino acid sequences among the ODATE-1 strain, Urabe strain and Miyahara strain revealed that the ODATE-1 strain was not related to the Urabe strain.     

Spirodiketopiperazine-based CCR5 antagonist: discovery of an antiretroviral drug candidate

Following the discovery that hydroxylated derivative 3 (Fig. 1) was one of the oxidative metabolites of the original lead 1, it was found that hydroxylated compound 4 possesses higher in vitro anti-HIV potency than the corresponding non-hydroxylated compound 2. Structural hybridation of 4 with the orally available analog 5 resulted in another orally-available spirodiketopiperazine CCR5 antagonist 6a that possesses more favorable pharmaceutical profile for use as a drug candidate.     

Synthesis and Anti-HIV Activity of 5-Fluorocytallene: N-Dimethylaminomethylene as a Facilitating Group in Acetylene → Allene Isomerization

Abstract

The synthesis and biological activity of 5-fluorocytallene (3a) is described. 5-Fluorocytosine (4) was alkylated with 1-benzoyloxy-4-bromo-2-butyne (5) to give N¹-(4-benzoyloxy-2-butyn-1-yl)-5-fluorocytosine (6). Debenzoylation led to N¹-(4-hydroxy-2-butyn-1-yl)-5-fluorocytosine (7a). The latter compound was transformed to the N⁴-dimethylaminomethylene derivative 8 which was isomerized in situ to the corresponding allene 9. Deprotection afforded 5-fluorocytallene (3a). Compound 3a suppressed the infectivity and replication of both laboratory and primary HIV-1 strains in vitro at nontoxic concentrations.     

Induction of intestinal ATP-binding cassette transporters by a phytosterol-derived liver X receptor agonist

The nuclear receptors liver X receptor (LXR) alpha and LXRbeta serve as oxysterol receptors and regulate the expression of genes involved in lipid metabolism. LXR activation induces the expression of ATP-binding cassette (ABC) transporters, such as ABCG5 and ABCG8, which inhibit intestinal absorption of cholesterol and phytosterols. Although several synthetic LXR agonists have been generated, these compounds have limited clinical application, because they cause hypertriglycemia by inducing the expression of lipogenic genes in the liver. We synthesized derivatives of phytosterols and found some of them to act as LXR agonists. Among them, YT-32 [(22E)-ergost-22-ene-1alpha,3beta-diol], which is related to ergosterol and brassicasterol, is the most potent LXR agonist. YT-32 directly bound to LXRalpha and LXRbeta and induced the interaction of LXRalpha with cofactors, such as steroid receptor coactivator-1, as effectively as the natural ligands, 22(R)-hydroxycholesterol and 24(S),25-epoxycholesterol. Although the nonsteroidal synthetic LXR agonist T0901317 induced the expression of intestinal ABC transporters and liver lipogenic genes, oral administration of YT-32 selectively activated intestinal ABC transporters in mice. Unlike T0901317 treatment, YT-32 inhibited intestinal cholesterol absorption without increasing plasma triglyceride levels. The phytosterol-derived LXR agonist YT-32 might selectively modulate intestinal cholesterol metabolism.     

The effect of low-pressure carbonation on the heat inactivation of Escherichia coli

The heat inactivating effect of low-pressure carbonation (LPC) at 1 MPa against Escherichia coli was enhanced to 3.5log orders. This study aimed to investigate the mechanisms of this increase in heat inactivation efficiency. The increased inactivation ratio was found to be the result of LPC-induced heat sensitization. This sensitization was not due to any physical damage to the cells as a result of the treatment. Following the depletion of intracellular ATP, the failure of the cells to discard protons caused an abnormal decrease in the intracellular pH. However, in the presence of glucose, the inactivation ratio decreased. In addition, a further increase in inactivation of more than 2log orders occurred in the presence of the protein synthesis inhibitor chloramphenicol. Hence, the decreased heat resistance of E. coli under LPC was most likely due to a depletion of intracellular ATP and a decreased capacity for protein synthesis.     

CD98 Heavy Chain Is a Potent Positive Regulator of CD4+ T Cell Proliferation and Interferon-γ Production In Vivo

Upon their recognition of antigens presented by the MHC, T cell proliferation is vital for clonal expansion and the acquisition of effector functions, which are essential for mounting adaptive immune responses. The CD98 heavy chain (CD98hc, Slc3a2) plays a crucial role in the proliferation of both CD4⁺ and CD8⁺ T cells, although it is unclear if CD98hc directly regulates the T cell effector functions that are not linked with T cell proliferation in vivo. Here, we demonstrate that CD98hc is required for both CD4⁺ T cell proliferation and Th1 functional differentiation. T cell-specific deletion of CD98hc did not affect T cell development in the thymus. CD98hc-deficient CD4⁺ T cells proliferated in vivo more slowly as compared with control T cells. C57BL/6 mice lacking CD98hc in their CD4⁺ T cells could not control Leishmania major infections due to lowered IFN-γ production, even with massive CD4⁺ T cell proliferation. CD98hc-deficient CD4⁺ T cells exhibited lower IFN-γ production compared with wild-type T cells, even when comparing IFN-γ expression in cells that underwent the same number of cell divisions. Therefore, these data indicate that CD98hc is required for CD4⁺ T cell expansion and functional Th1 differentiation in vivo, and suggest that CD98hc might be a good target for treating Th1-mediated immune disorders.     

Epigenetic heterogeneity at imprinted loci in normal populations

Genomic imprinting is the phenomenon by which the two alleles of certain genes are differentially expressed according to their parental origin. Extensive analysis of allelic expression at multiple imprinted loci in a normal population has not performed so far. In the present study, we examined the allelic expression pattern of three imprinted genes in a panel of 262 Japanese normal individuals. We observed differences in the extent of maintenance of allele-specific expression of the three genes. The allelic expression of small nuclear ribonucleoprotein N (SNRPN) was stringently regulated while that of multimembrane-spanning polyspecific transporter-like gene 1 (IMPT1) showed a large degree of variation. Significant biallelic expression of insulin-like growth factor II (IGF2) was observed in about 10% of normal individuals. Our findings add to the accumulating evidence for variable allelic expression at multiple loci in a normal human population. This epigenetic heterogeneity can be a stable trait and potentially influence individual phenotypes.     

Molecular and cytological analyses reveal distinct transformations of intestinal epithelial cells during <Emphasis Type="Italic">Xenopus</Emphasis> metamorphosis

Background

The thyroid hormone (T3)-induced formation of adult intestine during amphibian metamorphosis resembles the maturation of the mammalian intestine during postembryonic development, the period around birth when plasma T3 level peaks. This process involves de novo formation of adult intestinal stem cells as well as the removal of the larval epithelial cells through apoptosis. Earlier studies have revealed a number of cytological and molecular markers for the epithelial cells undergoing different changes during metamorphosis. However, the lack of established double labeling has made it difficult to ascertain the identities of the metamorphosing epithelial cells.

Results

Here, we carried out different double-staining with a number of cytological and molecular markers during T3-induced and natural metamorphosis in Xenopus laevis. Our studies demonstrated conclusively that the clusters of proliferating cells in the epithelium at the climax of metamorphosis are undifferentiated epithelial cells and express the well-known adult intestinal stem cell marker gene Lgr5. We further show that the adult stem cells and apoptotic larval epithelial cells are distinct epithelial cells during metamorphosis.

Conclusions

Our findings suggest that morphologically identical larval epithelial cells choose two alternative paths: programmed cell death or dedifferentiation to form adult stem cells, in response to T3 during metamorphosis with apoptosis occurring prior to the formation of the proliferating adult stem cell clusters (islets).