Constitutive activation of nuclear factor-E2-related factor 2 induces biotransformation enzyme and transporter expression in livers of mice with hepatocyte-specific deletion of Kelch-like ECH-associated protein 1

Chemicals that activate nuclear factor-E2-related factor 2 (Nrf2) often increase multidrug-resistance-associated protein (Mrp) expression in liver. Hepatocyte-specific deletion of Kelch-like ECH-associated protein 1 (Keap1) activates Nrf2. Use of hepatocyte-specific Keap1 deletion represents a nonpharmacological method to determine whether constitutive Nrf2 activation upregulates liver transporter expression in vivo. The mRNA, protein expression, and localization of several biotransformation and transporters were determined in livers of wild-type and hepatocyte-specific Keap1-null mice. Sulfotransferase 2a1/2, NADP(H):quinone oxidoreductase 1, cytochrome P450 2b10, 3a11, and glutamate-cysteine ligase catalytic subunit expression were increased in livers of Keap1-null mice. Organic anion-transporting polypeptide 1a1 expression was nearly abolished, as compared to that detected in livers of wild-type mice. By contrast, Mrp 1-5 mRNA and protein levels were increased in Keap1-null mouse livers, with Mrp4 expression being more than 15-fold higher than wild types. In summary, Nrf2 has a significant role in affecting Oatp and Mrp expressions.     

Photoprotective response of xanthophyll pigments during phytoplankton blooms in Sagami Bay, Japan

The relationship between the xanthophyll pool [diadinoxanthinplus diatoxanthin normalized to chlorophyll (Chl) a] and irradiancewas examined during phytoplankton blooms in Sagami Bay fromthe end of April to July 2000. In the case of Chl a concentrations>2 mg m^-3, a linear correlation was found between the xanthophyllpool and irradiance of the previous day. On the other hand,for Chl a concentrations <2 mg m^-3, the xanthophyll poolremained low and was independent of irradiance of the previousday. The results may indicate that photoprotection by xanthophyllpigments assists the development of phytoplankton blooms underhigh-irradiance conditions.     

Subcellular Localization of PMES-2 Proteins Regulated by Their two Cytoskeleton-Associated Domains

1. PMES-2 is a protein, of which mRNA is translocated to the neurites of hippocampal neurons. Since the protein is present in the postsynaptic density, contributions to synaptic function have been predicted. 2. To elucidate the protein-protein interaction of PMES-2, yeast two-hybrid screening was performed with PMES-2 partial polypeptides as baits. We found that PMES-2 interacted with dynein light chain-2 (DLC-2), a light chain subunit of myosin-V and cytoplasmic dynein, via the C-terminal 20 amino acids. Exogenous PMES-2 colocalized with F-actin at the cell periphery, while a PMES-2 mutant lacking the DLC-binding site localized primarily in the nucleus. 3. This dual-targeting of PMES-2 constructs depends on an effector domain-like motif in the N-terminus. 4. These results indicate that PMES-2 links a motor complex to the membrane skeleton and that DLC-1/2 inhibits PMES-2 nuclear localization. PMES-2 possibly modifies the cytoskeletal architecture and protein transport at the synapse and/or regulates signal transduction from the synapse to the nucleus.     

Evaluation of <Emphasis Type="Italic">Fusarium solani</Emphasis> Hyphae and Conidia Susceptibility to Amphotericin B and Itraconazole: Study of a Clinical Case

Fusarium species are hyaline moulds belonging to the hyalohyphomycosis group that are usually found in the soil and plants. This organism has emerged as a cause of disseminated invasive disease. The correlation between in vitro value and clinical efficacy is low and many patients remain unresponsive to treatment despite in vitro susceptibility. We determined growth control for Fusarium solani using the BioCell-Tracer system that measures the growth rate of a single fungal hypha, and the effect of different concentrations of amphotericin B and itraconazole. The MIC for these two drugs was also determined by a broth microdilution technique, using RPMI 1640. Different MICs for amphotericin B were obtained by the two different methods. This paper describes a case of infection due to Fusarium solani in an allogeneic bone marrow transplanted patient, the microbiological diagnostic, antifungal susceptibility tests for conidia and hypha and clinical correlation.     

Human cryptococcosis: relationship of environmental and clinical strains of <Emphasis Type="Italic">Cryptococcus neoformans</Emphasis> var. <Emphasis Type="Italic">neoformans </Emphasis>from urban and rural areas

Forty-five clinical and 55 environmental strains of Cryptococcus neoformans var. neoformans from São Paulo, Brazil, were tested for their susceptibilities to amphotericin B, fluconazole, itraconazole, and flucytosine by the broth microdilution method according to the National Committee of Clinical Laboratory Standards guidelines. Electrophoretic karyotypes analysis by counter-clamped homogeneous electrophoresis was used to compare their genetic relatedness. Molecular typing revealed three clinical profiles very similar to two environmental profiles and an identical environmental and clinical profile. The results showed that human cryptococcosis can be acquired from environmental strains, which had similar minimum inhibitory concentration values to clinical strains, for antifungal agents.     

The RNA ligands for mouse proline-rich RNA-binding protein (mouse Prrp) contain two consensus sequences in separate loop structure

Mouse proline-rich RNA-binding protein (mPrrp) is a mouse ortholog of Xenopus Prrp, which binds to a vegetal localization element (VLE) in the 3′-untranslated region (3′-UTR) of Vg1 mRNA and is expected to be involved in the transport and/or localization of Vg1 mRNA to the vegetal cortex of oocytes. In mouse testis, mPrrp protein is abundantly expressed in the nuclei of pachytene spermatocytes and round spermatids, and shifts to the cytoplasm in elongating spermatids. To gain an insight into the function of mPrrp in male germ cells, we performed in vitro RNA selection (SELEX) to determine the RNA ligand sequence of mPrrp. This analysis revealed that many of the selected clones contained both of two conserved elements, AAAUAG and GU_1–3AG. RNA-binding study on deletion mutants and secondary structure analyses of the selected RNA revealed that a two-loop structure containing the conserved elements is required for high-affinity binding to mPrrp. Furthermore, we found that the target mRNAs of Xenopus Prrp contain intact AAAUAG and GU_1–3AG sequences in the 3′-UTR, suggesting that these binding sequences are shared by Prrps of Xenopus and mouse.