3-Deoxyglucosone reductase in dog adrenal glands. Identification as aldose reductase

3-Deoxyglucosone is one of the major cytotoxic intermediates in the Maillard reaction. Adrenal glands showed the highest NADPH-linked 3-deoxyglucosone reductase activity of dog tissues. The enzyme was purified to homogeneity from the adrenal glands, and demonstrated to be structurally, functionally and immunologically identical with aldose reductase, which comprises about 6% of the soluble adrenal proteins.

Crystallization of mouse lung carbonyl reductase complexed with NADPH and analysis of symmetry of its tetrameric molecule

Mouse lung carbonyl reductase (MLCR), which belongs to the short-chain dehydrogenase/reductase family, is an oxidoreductase involved in the metabolism of biogenic and xenobiotic carbonyl compounds. The crystals of MLCR complexed with its cofactor NADPH belong to a monoclinic space group P2(1) with dimensions a = 79.73 A, b = 105.5 A, c = 60.87 A, and beta = 91.43 degrees. X-ray diffraction data were collected up to 1.8 A resolution using a macromolecule-oriented Weissenberg camera at the Photon Factory synchrotron radiation source. Studies using a self-rotation function revealed the presence of a twofold rotational symmetry relating the subunits. This suggests that the tetrameric MLCR molecule has the 222 point group symmetry.

[Effect of ritodrine hydrochloride on fetal perfusion pressure in dually perfused human placenta]

Ritodrine hydrochloride is widely used in clinical obstetrics for the prevention of premature labor, but the knowledge of its effect on fetal circulation is limited. The purpose of this study was to elucidate changes in vascular resistance in the fetal placental circulation by using the dually perfused human placenta in vitro. The viability of the perfused placenta was maintained during the experiments because the production rate of hCG was constant. The transfer of ritodrine hydrochloride was observed and its concentration on the fetal side was about one third of maternal side at 120 min subsequent to the injection. The fetal perfusion pressure during the control period was 38.6 +/- 7.0 mmHg (mean +/- S.D., n=3). After the addition of ritodrine hydrochloride to the maternal circulation, the fetal perfusion pressure was decreased dose-dependently. The pressure was 95.4 +/- 1.8% at 80 ng/ml of ritodrine hydrochloride which was within the clinical concentration limits. It is concluded that ritodrine hydrochloride acts as a vasodilator on the fetal vasculature in the human placenta.

Increased serum IgE level and interleukin-4 release from cultured lymphocytes from a patient with adult onset Still's disease

OBJECTIVE

To evaluate the relationship between high serum levels of IgE and the release of interleukin-4 (IL-4) from cultured lymphocytes of a patient with adult onset Still's disease.

METHODS

IL-4 concentrations in plasma and culture from inactivated peripheral blood mononuclear cells were assessed by enzyme immunoassay during febrile episodes and remission.

RESULTS

A high level of IL-4 was detected by enzyme immunoassay in the peripheral blood mononuclear cells cultured from the patient. These seemed to correspond with a febrile episode and a high serum IgE concentration.

CONCLUSION

Increased serum IgE concentrations during a febrile episode are rare in patients with adult onset Still's disease, but the relationship between the high levels of serum IgE and IL-4 in cultured lymphocytes may provide clues to pathogenesis of the condition.

Over-expression of pig lung carbonyl reductase in Escherichia coli

Tetrameric carbonyl reductase of pig lung has been shown by cDNA cloning to be a member of the short-chain dehydrogenase family of enzymes. Construction of the carbonyl reductase cDNA in an expression vector yielded an abundant, enzymatically active enzyme in Escherichia coli. The recombinant enzyme was purified to homogeneity and shown to be structurally, immunologically and functionally similar to lung carbonyl reductase.

Expression and kinetic properties of a recombinant 3 alpha-hydroxysteroid/dihydrodiol dehydrogenase isoenzyme of human liver

Human liver cytosol contains multiple forms of 3 alpha-hydroxysteroid dehydrogenase and dihydrodiol dehydrogenase with hydroxysteroid dehydrogenase activity, and multiple cDNAs for the enzymes have been cloned from human liver cDNA libraries. To understand the relationship of the multiple enzyme froms to the genes, a cDNA, which has been reported to code for an isoenzyme of human liver 3 alpha-hydroxysteroid/dihydrodiol dehydrogenase, was expressed in Escherichia coli. The recombinant enzyme showed structural and functional properties almost identical to those of the isoenzyme purified from human liver. In addition, the recombinant isoenzyme efficiently reduced 5 alpha-dihydrotestosterone and 5 beta-dihydrocortisone, the known substrates of human liver 3 alpha-hydroxysteroid dehydrogenase and chlordecone reductase previously purified, which suggests that these human liver enzymes are identical. Furthermore, the steady-state kinetic data for NADP(+)-linked (S)-1-indanol oxidation by the recombinant isoenzyme were consistent with a sequential ordered mechanism in which NADP+ binds first. Phenolphthalein inhibited this isoenzyme much more potently than it did the other human liver dihydrodiol dehydrogenases, and was a competitive inhibitor (Ki = 20 nM) that bound to the enzyme-NADP+ complex.

The C-terminal region of p21SDI1/WAF1/CIP1 is involved in proliferating cell nuclear antigen binding but does not appear to be required for growth inhibition

The cyclin-dependent kinase (Cdk) inhibitor p21SDI1/WAF1/CIP1 has been found to be involved in cell senescence, cell cycle arrest, and differentiation. p21SDI1 inhibits the activity of several Cdks, in contrast to other inhibitors such as p15INK4B and p16INK4A, which act on specific cyclin-Cdk complexes. Of interest were reports that p21SDI1 also bound proliferating cell nuclear antigen (PCNA), an auxiliary protein for DNA polymerase delta, and inhibited DNA replication but not DNA repair in vitro. To better understand the function of this interaction in vivo, we first determined the region of p21SDI1 that was needed for PCNA binding. Analysis of deletion mutants of p21SDI1, which covered the majority of the protein, revealed that deletion of either amino acids 142-147 or 149-154 resulted in loss of ability to bind a glutathione S-transferase-PCNA fusion protein. Site-directed mutagenesis in this region led to the identification of the PCNA binding motif RQXXMTXFYXXXR and demonstrated that mutation of either amino acid Met-147 or Phe-150 resulted in almost complete ablation of PCNA binding. Interestingly, when we determined DNA synthesis inhibitory activity of deletion mutants or point mutants that were unable to bind Cdk2 and/or PCNA, we found that loss of binding to PCNA did not affect inhibitory activity, whereas lack of Cdk2 binding greatly reduced the same. This result suggests that the primary mechanism for inhibition of DNA synthesis by p21SDI1 occurs via inhibition of Cdk activity.

Disposition of S-1108, a new oral cephem antibiotic, and metabolic fate of pivalic acid liberated from [pivaloyl-14C]S-1108 in rats and dogs

[pivaloyl-14C]S-1108, which is 14C labeled at the pivalic acid moiety of the pivaloyloxymethyl side chain of S-1108, was administered orally to rats and dogs, and the disposition of pivalic acid cleft from S-1108 was examined. Besides pivaloylcarnitine and pivaloylglucuronide, pivaloylglycine was identified in dog urine as a metabolite of pivalic acid by thin-layer chromatography and high-performance liquid chromatography analysis. The concentrations in the plasma of rats to which doses of 6.65, 26.6, and 532 mg/kg of body weight were administered showed dose-proportionate levels. The radioactivity was eliminated rapidly, with a half-life of approximately 3 h until 24 h at both the 6.65- and 26.6-mg/kg doses. Free pivalic acid in plasma accounted for more than 80% of the concentration of radioactivity. Radioactivity was distributed throughout the body and was eliminated quickly at a rate similar to that of radioactivity from plasma. Most of the absorbed radioactivity was excreted in the urine, and it was completed within 24 h after administration. In dogs, the half-life of radioactivity in plasma was longer than that in the rats. The ratio of free pivalic acid in plasma was 60 to 70% of the radioactivity in plasma. The concentration of radioactivity in the liver, cortex of the kidney, and skeletal muscle 144 h after oral dosing was more than 10 times higher than the concentration in plasma for all doses. Urinary excretion in dogs was slower than that in rats. The differences in the disposition of pivalic acid between dogs and rats may account for differences in the degree of skeletal muscle disorders. The safety in humans of S-1108 given at 200 mg three times a day is discussed in relation to the metabolic formation of the carnitine conjugate of pivalic acid and the reduction of the carnitine concentration in plasma.

Effects of citalopram, a synthetic serotonin uptake inhibitor, on indoleamine and catecholamine concentrations in the cerebrospinal fluid of freely moving rats

We studied changes in the concentrations of 5-hydroxytryptamine (5-HT), other indoleamines, and catecholamines in the cerebrospinal fluid (CSF) of freely-moving rats that had been administered citalopram, +/-1-[3- (Dimethylamino)propyl)-1-(4-fluorophenyl)-1, 3-dihydro-5-isobenzo-furancarbonitrile hydrobromide), a selective inhibitor of 5-HT uptake. In a microdialysis experiment, the intracerebral extracellular free 5-HT increased significantly, peaking 60 to 90 min after citalopram (30 mg/kg p.o.) was administered. The 5-HT concentrations in CSF from the cisterna magna increased significantly, reaching a maximum 6 hours after a single dose of citalopram (30 mg/kg p.o.) was given. Six hours after this dose, the CSF 5-HT concentration in the cisterna magna was significantly increased, and the 5-hydroxyindoleacetic acid (5-HIAA) concentration was significantly decreased. There were non-significant changes in the other indoleamines (tryptophan, 5-hydroxytryptophan, and kynurenine) and in the catecholamines (dopamine, homovanillic acid, normetanephrine, and 3-methoxy-4-hydroxyphenethyleneglycol). The 5-HT/tryptophan ratio was correlated significantly with the kynurenine/tryptophan ratio before treatment with citalopram (r = 0.81, p = 0.051), indicative that there is coordination of the serotonin and kynurenine pathways in normal rats. In the animals posttreatment there was no such correlation, suggesting that the changes in 5-HT are independent of the kynurenine system at least within the 6 hours postreatment. These CSF results appear to reflect selective inhibition of 5-HT uptake in brain tissues by citalopram that is not associated with changes in catecholamines.

Exit from G0 and entry into the cell cycle of cells expressing p21Sdi1 antisense RNA

p21Sdi1 (also known as Cip1 and Waf1), an inhibitor of DNA synthesis cloned from senescent human fibroblasts, is an inhibitor of G1 cyclin-dependent kinases (Cdks) in vitro and is transcriptionally regulated by wild-type p53. In addition, p21Sdi1 has been found to inhibit DNA replication by direct interaction with proliferating cell nuclear antigen. In this study we analyzed normal human fibroblast cells arrested in G0 and determined that an excess of p21Sdi1 was present after immunodepletion of various cyclins and Cdks, in contrast to mitogen-stimulated cells in early S phase. Expression of antisense p21Sdi1 RNA in G0-arrested cells resulted in induction of DNA synthesis as well as entry into mitosis. These results suggest that p21Sdi1 functions in G0 and early G1 and that decreased expression of the gene is necessary for cell cycle progression.

Molecular cloning and characterization of mouse estradiol 17 beta-dehydrogenase (A-specific), a member of the aldoketoreductase family

Several mammalian livers contain monomeric 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) with A-stereospecificity in hydrogen transfer, which differs from the B-specific dimeric enzyme of human placenta in its ability to catalyze the oxidoreduction of xenobiotic trans-dihydrodiols of aromatic hydrocarbons and carbonyl compounds. Here, we report the isolation and characterization of a mouse cDNA clone encoding monomeric 17 beta-HSD of the liver. This clone had an entire coding region for a protein of 323 amino acid residues with a molecular weight of 37,055. The deduced sequence of the protein aligned with a high degree of identity with rat and rabbit 20 alpha-HSDs, rat and human 3 alpha-HSD/dihydrodiol dehydrogenases, and bovine prostaglandin F synthase, which are members of the aldoketoreductase family, but was distinct from human 17 beta-HSD and carbonyl reductase, members of the short chain dehydrogenases. The expression of the cDNA in Escherichia coli resulted in synthesis of a protein that was active toward androgens, estrogens, and xenobiotic substrates. The recombinant and mouse liver 17 beta-HSDs also exhibited low 20 alpha-HSD activity toward progestins, which is similar to bifunctional activity of human placental 17 beta-HSD. Therefore, the mouse enzyme was given the designation of estradiol 17 beta-dehydrogenase (A-specific). Northern analysis of mouse tissues revealed the existence of a single 1.7-kilobase 17 beta-HSD mRNA species in the liver, kidney, testis, and stomach. The liver mRNA content was considerably more abundant than those found in the other tissues, as 17 beta-HSD protein was mainly detected in the liver by Western analysis.

Single-cell observation of calcium signals in T cells and antigen-presenting cells during antigen presentation

Intracellular calcium ion mobilization in T-cell hybridomas and antigen-presenting cells (APC) during the interaction was observed using confocal fluorescence microscopy. No calcium signal was detected in non-activated T-cell hybridomas by antigen presentation. However, in activated T-cell hybridomas, intracellular calcium ion concentration rapidly increased by antigen presentation and thereafter apoptosis was induced. On the contrary, during the interaction with T-cell hybridomas, calcium signal was induced in APCs irrespective of the activation of T-cell hybridomas. Chemical modification of APCs with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide, which is known to induce T-cell unresponsiveness during antigen presentation, inhibited cap formation of surface MHC class II molecules and suppressed calcium signals during the interaction with T-cell hybridomas.

Triggering of calcium signals in antigen-specific B-cells on the supported lipid monolayers

Using supported lipid monolayers we have studied here calcium signals in antigen-specific B-cells (TNP-specific B-cell hybridomas, TP67.21) triggered by lipid hapten (TNP-Cap-DPPE). Stimulation of the B-cell hybridomas (TP67.21) with a supported DPPC monolayers containing 1% TNP-Cap-DPPE increased the intracellular free calcium ion concentration [Ca2+]i in B-cells. None of B-cells responded to a DPPC monolayers without lipid hapten (TNF-Cap-DPPE). Triggering for calcium signals was clearly dependent on the fluidity of the lipid monolayers. Solid DPPC and DSPC monolayers triggered the calcium signals more efficiently than the fluid DMPC monolayers did. These calcium signals became apparently more efficient in the presence of cholesterol. All of these results suggested that the rigidity of cross-linking for antigen receptors (mIgM) may be a crucial role for triggering calcium signals in B-cells.

Cloning, expression and tissue distribution of mouse tetrameric carbonyl reductase. Identity with an adipocyte 27-kDa protein

We previously cloned a cDNA for pig lung tetrameric carbonyl reductase which shows significant similarity to a putative 27-kDa protein predicted from the cDNA for murine adipocyte RNA which had been increased in its differentiation [Nakanishi, M., Deyashiki, Y., Nakayama, T., Sato, K. & Hara, A. (1993) Biochem. Biophys. Res. Commun. 194, 1311-1316]. In this investigation, we isolated and sequenced a full-length cDNA for the tetrameric enzyme from a mouse lung cDNA library. It consisted of 984 bp and coded for a protein of 244 amino acid residues, of which 202 residues were identified by protein sequencing. The expression of the cDNA in Escherichia coli resulted in synthesis of a protein structurally and functionally similar to the enzyme purified from mouse lung. The nucleotide sequence of the cDNA was virtually identical to that of the cDNA for the adipocyte 27-kDa protein. Although Northern-blot analysis of mouse tissues showed that enzyme mRNA to be 1.1 kb only in lung, low expression of the mRNA in all the extrapulmonary tissues, including adipose tissue, was demonstrated by a reverse-transcription PCR method. Western-blot analysis also indicated the presence of the enzyme in the adipose tissue. This is the first report on an identification of the putative gene product of adipocytes as tetrameric carbonyl reductase, the expression of which is tissue-specifically regulated.

Identification of the active region of the DNA synthesis inhibitory gene p21Sdi1/CIP1/WAF1

The cloning of the negative growth regulatory gene, p21Sdi1, has led to the convergence of the fields of cellular senescence, cell cycle regulation and tumor suppression. This gene was first cloned as an inhibitor of DNA synthesis that was overexpressed in terminally non-dividing senescent human fibroblasts (SD11) and later as a p53 transactivated gene (WAF1) and a Cdk-interacting protein (CIP1, p21) that inhibited cyclin-dependent kinase activity. To identify the active region(s) of p21Sdi1, cDNA constructs encoding various deleted forms of the protein were analyzed. Amino acids 22-71 were found to be the minimal region required for DNA synthesis inhibition. Amino acids 49-71 were involved in binding to Cdk2, and constructs deleted in this region expressed proteins that were unable to inhibit Cdk2 kinase activity in vitro. The latter stretch of amino acids shared sequence similarity with amino acids 60-76 of the p27Kip1 protein, another Cdk inhibitor. Point mutations made in p21Sdi1 in this region confirmed that amino acids common to both proteins were involved in DNA synthesis inhibition. Additionally, a chimeric protein, in which amino acids 49-65 of p21Sdi1 were substituted with amino acids 60-76 of p27Kip1, had almost the same DNA synthesis inhibitory activity as the wild-type protein. The results indicate that the region of sequence similarity between p21Sdi1 and p27Kip1 encodes an inhibitory motif characteristic of this family of Cdk inhibitors.

Heterogeneous distribution of 125I-insulin binding sites in the liver of fed and fasted mice

A microradioautography made three min. after intravenous injection of 125I-insulin was used to study the distribution of insulin binding sites in the liver of fed and fasted mice. A substantial specific binding of 125I-insulin to liver parenchymal cells could be seen in these mice, whereas radioautographs from animals injected with 125I-insulin plus an excess of unlabelled insulin showed only trace amounts of silver grains. In both fed and fasted mice, a density gradient of the binding from the periportal zone to the perivenous zone was evident, and the binding in each zone was significantly higher in the fasted mice than in the fed mice.

[Successful treatment of acute myelomonocytic leukemia developed from MDS with cytarabine ocfosfate (SPAC)]

A 65-year-old female with acute myelomonocytic leukemia (AMMoL) developed from myelodysplastic syndrome (MDS), successfully treated with cytarabine ocfosfate (SPAC) is reported. Ubenimex, calcitriol and corticosteroid had a minor effect on her MDS. Since she had severe anemia and congestive heart failure on developing leukemia, she was treated with oral administration of SPAC, a cytidine deaminase resistant derivative of Ara-C. After the second course of SPAC (200 mg/day, for 14-28 days), marked erythroid bursts were found and she entered complete remission. The samplings of SPAC and its metabolites of SPAC were investigated in 2 cases including this case, but there seemed to be no relation between their content and effects. In AML patients, especially in cases developed from MDS, SPAC might be useful because it can be given orally even in an outpatient.

Confocal fluorescence microscopy for studying thapsigargin-induced bivalent-cation entry into B cells

We studied thapsigargin-induced bivalent-cation entry into antigen-specific B cells (TP67.21) with a confocal fluorescence microscope. Confocal fluorescence images of fluo-3-loaded B cells showed that thapsigargin-stimulated Ca2+ signals were transferred not only to the cytoplasm but also to the nucleus. In the absence of external Ca2+ ions, the free Ca2+ concentrations both in the cytosol and in the nucleus declined to basal levels by 5 min after addition of thapsigargin. However, subsequent addition of Ca2+ in the external medium made the fluo-3 (fura-2) fluorescence intensity rise, reflecting the fact that Ca2+ accumulated again in the nucleus as well as in the cytoplasm. Then, we added Ba2+ and Mn2+ instead of Ca2+, because Ba2+ and Mn2+ are known to enter via Ca2+ channels. The addition of Ba2+ and Mn2+ in the external medium quenched the fluo-3 fluorescence both in the nucleus and in the cytoplasm of B cells. This suggested the possibility that the increase in intranuclear Ca2+ after thapsigargin stimulation may come from the cytoplasm, not from the nuclear stores.

[Apoptosis and cell growth fraction in normal, dysplastic and neoplastic squamous epithelium of uterine cervix]

To assess the transformation of cellular characteristics during a neoplastic change in uterine cervical epithelium, the populations of cells in apoptosis as well as proliferating cycle were examined in normal cervical epithelium, dysplastic change, carcinoma in situ and invasive carcinoma. The percentage of apoptotic cells (%DNA Fr.) decreased with the neoplastic change and was significantly lower in the carcinoma in situ group than in the dysplasia group. Conversely, the percentage of cells in the proliferating cycle (%GF) increased with the neoplastic change and was significantly higher in the dysplasia group than in the normal group. The ratio of %DNA Fr. to % GF was more than 1.0 in the normal group and dysplasia group, but it was less than 1.0 in the carcinoma in situ group and invasive carcinoma group. No significant correlation between %DNA Fr. and %GF was found. These results suggested to us that the decrease in apoptosis may reflect the atypical change in cervical epithelial cells during their neoplastic change, and the proliferative activity in neoplastic lesion was found when the cervical epithelium with dysplastic change was transformed to the carcinoma in situ.

Thapsigargin-induced nuclear calcium signals in rat basophilic leukaemia cells

By a confocal fluorescence microscope with an argon-ion laser (488 nm) and a He-Cd laser (325 nm) we have studied thapsigargin-induced calcium signals in individual rat basophilic leukaemia (RBL-2H3) cells. In the presence or absence of external calcium ions, thapsigargin-induced calcium signals were transferred to the nucleus as well as to the cytoplasm of RBL-2H3 cells. The calcium signals were generally much stronger in the nucleus than in the cytoplasm. However, some of the RBL-2H3 cells had apparently reduced nuclear calcium signals. They had a basophil-like bilobed (multilobed) nucleus, although most RBL-2H3 cells had a mast-cell-like monolobed nucleus. In the cells with a bilobed nucleus, IgE-receptor-mediated calcium signals were neither transferred to the nucleus nor to the cytoplasm. The results gave a new insight into the understanding of the mechanism of the nuclear calcium signals in RBL-2H3 cells.

An initial signal of activation of rat peritoneal mast cells stimulated by Datura stramonium agglutinin: a confocal fluorescence microscopic analysis of intracellular calcium ion and cytoskeletal assembly

A confocal fluorescence microscope using fluo-3 and 9-(dicyanovinyl)- julolidine (DCVJ) was used to study the mast cell activation by the N-acetyl glucosamine oligomer specific lectin Datura stramonium agglutinin (DSA) and inhibition by antagonist lectins having affinity to N-acetyl glucosamine (GlcNAc). DSA induced a transient increase in intracellular free calcium concentration ([Ca2+]i) followed by cytoskeletal disassembly and reassembly in rat peritoneal mast cells. These changes induced by DSA resulted in histamine release. The time course of fluorescence intensity in mast cells loaded with fluo-3- or DCVJ and activated by DSA resembled those activated by the basic polymer compound 48/80. Inhibition of [Ca2+]i rise by antagonist lectins was responsible for the inhibition of cytoskeletal assembly and the consequent histamine release induced by DSA. At the level of the individual cell, a mast cell stimulated by DSA responds in an all-or-none fashion. DSA possible induced intracellular calcium mobilization and cytoskeletal change by recognizing the GlcNAc-oligomer residues of specific glycoproteins of mast cells.

Familial occurrence of two patients with malignant rheumatoid arthritis

In Japan, patients with rheumatoid arthritis associated with severe extra-articular manifestations due to vasculitis are diagnosed as having malignant rheumatoid arthritis. We report the occurrence of two cases of malignant rheumatoid arthritis in a Japanese family. Both patients, a father and son, expressed HLA-DR4 (Dw15), and were infected with Epstein-Barr virus. Moreover, the father developed malignant rheumatoid arthritis during reactivation of the Epstein-Barr virus. An unaffected male family member with the same HLA haplotypes was not infected by the virus. The possible role of the virus infection in the pathogenesis of malignant rheumatoid arthritis in a genetically susceptible family is discussed.

Interaction between ganglioside-containing liposome and rat T-lymphocyte: confocal fluorescence microscopic study

Interaction between rat T-lymphocytes and a ganglioside (GM3, GD3, GT1b, or GQ1b)-containing liposome was investigated in vitro. The direct stimulation of T cell by a ganglioside-containing liposome was followed by monitoring an increase in the intracellular calcium signal using a confocal laser fluorescence microscopic method. The GT1b- or GQ1b-containing liposome strongly stimulated the cell, while the GM3- or GD3-containing liposome showed much less effect. Free gangliosides did not stimulate the cell at all under the same condition. The extent of the stimulation depended on the surface density of GT1b on the liposome accompanied by a clear threshold concentration. The efficiency of this direct T cell stimulation with the ganglioside-containing liposome was closely related to the efficiency of the tumor growth suppression reported previously by ourselves.