Proximal and core DNA elements are required for efficient angiotensinogen promoter activation during adipogenic differentiation

Angiotensinogen is abundantly expressed in adipose tissue as well as in liver where it is mainly produced. To address the mechanism of this adipogenic expression, promoter regions of the mouse angiotensinogen gene are fused to the chloramphenicol acetyltransferase reporter gene and stably transfected into 3T3-L1 preadipocytes. Promoter activity correlates well with an increase of mRNA levels during adipogenic differentiation, thereby demonstrating that the induction is primarily due to transcriptional activation. Deletion analysis indicates that the proximal promoter region from -96 to +22 is able to mediate the chloramphenicol acetyltransferase induction and identifies two transcriptionally active regions: AGE1 (position -399 to -139) and AGE2 (position -96 to -52). Heterologous promoter assay reveals that AGE1 behaves with a constitutive enhancer-like property and that AGE2 functions as a differentiation-inducible activator. Gel shift experiments show that AGE2 specifically binds a novel factor (AGF2), which is induced upon differentiation. Furthermore, a constitutive factor (AGF3) binds to the core promoter region including the exon 1 (from -6 to +22, AGE3). Mutations within either AGE2 or AGE3 that disrupt nuclear factors binding in vitro dramatically reduced the chloramphenicol acetyltransferase activation in the native promoter context. These results suggest that both AGE2 and AGE3 are necessary for mediating efficient activation of the mouse angiotensinogen promoter during adipogenic differentiation.

Effect of ethanol on the development and maturation of synapses in the rat hippocampus: a quantitative electron-microscopic study

The effects of chronic ethanol administration on the development and maturation of synapses in the strata radiatum and lacunosum-moleculare of CA1 in the hippocampus were quantitatively examined in rats exposed to ethanol for the entire period of fetal life as well as the whole period of postnatal life. Synapse densities in the strata radiatum and lacunosum-moleculare of the ethanol-treated group were significantly lower than those of the control group at 2, 14, 21, and 70 days of age. However, the rates of density reduction did not change between either of the strata that receive different groups of afferent fibers. The ratio of axospinous to axoshaftic synapses also did not change between control and ethanol-treated groups. These data suggest that chronic administration of ethanol reduces the density of synapses in this area and that this effect is not specific to neither the type of afferent fibers nor the type of synapses.

[Focal glomerular sclerosis in a sibling]

We described here one sibling with focal glomerular sclerosis. Proteinuria was noticed at the age of five in brother and four in sister. Both of them developed nephrotic syndrome shortly after the discovery of proteinuria. The nephrotic syndrome was resistant to corticosteroid, immunosuppressive agents or the combination of these drugs. Percutaneous renal biopsy in them revealed morphological and immunohistological features compatible to focal glomerular sclerosis. HLA typing in HLA-A, B, C and DR loci was identical to both. This observation suggests that genetic factors is associated with the pathogenesis of focal glomerular sclerosis.

A novel human monoclonal antibody directed to a tumor-associated antigen

Twelve human monoclonal antibodies (HuMAb) were established by the fusion of (mouse x human) heteromyeloma cells with B-lymphoblastoid cells derived from the regional lymph nodes of three patients with squamous cell carcinoma of the lung. They were tested for reactivity to two kinds of proteins (purified protein derivatives and bovine serum albumin) by ELISA, Sq-19 (squamous cell carcinoma) culture cells by indirect membrane immunofluorescence tests, and Sq-19 tumor xenograft by immunohistological study. Among them, one HuMAb 904F (IgM, lambda) was selected. In indirect membrane immunofluorescence tests, this 904F antibody reacted with various kinds of cell lines, e.g. lung cancer, esophageal cancer, endometrial cancer, and stomach cancer. It did not react with malignant hematopoietic and diploid fibroblast cell lines. Immunohistologically, it stained the tumor nests of squamous cell carcinoma, adenocarcinoma, and large cell carcinoma of the lung. It also stained those of esophagus and colon, but not those of small cell carcinoma of lung, or stomach. On frozen-section specimens of normal tissues from various organs, it showed only limited areas of positive staining. Limited positive findings were observed at a reticular zone of the adrenal gland, at the esophagus as weak staining, and at islets of the pancreas as very weak staining. Western blotting analysis demonstrated that it recognized a 54 kDa trypsin-sensitive molecule which is expressed on the surface of tumor cells. These results suggest the 904F monoclonal antibody detects a novel tumor-associated antigen which is recognized by the human immune system.

Production of transgenic rats using pregnant and pseudopregnant rats prepared at a breeding farm

We used pregnant and pseudopregnant Wistar-Imamichi rats, prepared at a breeding farm, for production of transgenic rats. The donor and recipient rats were transported to our facility for ova manipulation and embryo implantation, respectively. As a foreign gene, 1.9 kb of a hybrid gene was constructed with the rat renin promoter and chloramphenicol acetyltransferase-coding gene. Fertilized oocytes were collected from the donor and the foreign DNA was microinjected into the pronuclei of 539 oocytes by the method of Hochi. The manipulated oocytes were cultured to the 2-cell stage. One hundred seventeen 2-cell embryos were implanted in the recipient rats. Of 67 newborns, 55 rats grew up to be 3-week-old weanlings. Genomic DNA was extracted from the tail of these weanlings and examined by polymerase chain reaction analysis. Six transgenic rats were found to have been generated by the present method. In this way, transgenic rats were produced by an efficient combination of breeding farm utilization and laboratory research.

Levels of androgens and danazol metabolites in serum during danazol therapy

Thirteen women who had endometriosis were treated with danazol (300 to 400 mg/d). Levels of androgens and danazol metabolites in serum and the influences of danazol metabolites on the assays for serum androgen were investigated during danazol therapy. Serum DHEAS significantly increased (P < 0.05), but serum DHEA slightly decreased. Serum T levels, measured by direct assay, were markedly elevated. However, measured after HPLC separation, the T levels in serum were significantly decreased (P < 0.05). There were considerable cross-reactions between danazol metabolites and androgens (T, DHEA, and A) in RIA. Purification of androgens using column chromatography was necessary to measure serum androgens precisely.

Chimeric renin-angiotensin system demonstrates sustained increase in blood pressure of transgenic mice carrying both human renin and human angiotensinogen genes

A reaction between enzyme renin and its only natural substrate angiotensinogen is the initial and rate-limiting step for producing a potent vasoconstrictor angiotensin II as the final product of the renin-angiotensin system, a contributory factor in the pathogenesis of hypertension. In order to assess the role of the interaction of human renin with human angiotensinogen in the development of high blood pressure, we have constructed the chimeric renin-angiotensin cascade in mice comprising both human renin and human angiotensinogen as well as the endogenous angiotensin-converting enzyme and angiotensin II receptor by cross-mating separate lines of transgenic mice carrying either the human renin or human angiotensinogen genes. Although each single gene carrier did not develop hypertension despite the observed normal tissue-specific expression of the transgenes, dual gene strains exhibited a chronically sustained increase in blood pressure. Administration of a human renin-specific inhibitor (ES-8891) was effective in reducing the elevated blood pressure only against the cross-mated hybrid mice, but treatment of an angiotensin-converting enzyme inhibitor (captopril) and a selective antagonist (DuP 753) directed at the angiotensin II receptor decreased the basal level of blood pressure even in single gene carriers as well as in dual gene mice. These results clearly demonstrated that the sustained increase in blood pressure of the hybrid mice was initiated by the interaction between the products of the two human genes.

A simple method of hybridohistochemistry for detection of renin mRNA in the mouse kidney

Hybridohistochemistry was applied for the detection of renin mRNA in the mouse kidney with a digoxigenin-labeled probe, synthesized as the sense and antisense RNAs from Ren-1 cDNA in the presence of digoxigenin-dUTP. Renin mRNA was detected in the juxtaglomerular cells located in the vicinity of the glomerular vascular poles of the kidney using the digoxigenin-labeled antisense RNA as a probe. Using the sense RNA as a probe, no signal was detected anywhere. In neighboring serial sections, the same cells reacted immunohistochemically to rabbit anti-mouse submandibular gland renin serum as in hybridohistochemistry. As we used the probe labeled with digoxigenin as a non-radioisotopic marker, there was no need for special handling other than that in immunohistochemistry. It was concluded that the simple procedure given in the present study is useful for the detection of mRNA.

Structures of asparagine linked oligosaccharides of immunoglobulins (IgY) isolated from egg-yolk of Japanese quail

Structures of the Asn linked oligosaccharides of quail egg-yolk immunoglobulin (IgY) were determined in this study. Asn linked oligosaccharides were cleaved from IgY by hydrazinolysis and labelled with p-aminobenzoic acid ethyl ester (ABEE) after N-acetylation. The ABEE labelled oligosaccharides were then fractionated by a combination of Concanavalin A-agarose column chromatography and anion exchange, normal phase and reversed phase HPLC before their structures were determined by sequential exoglycosidase digestion, methylation analysis, HPLC, and 500 MHz 1H-NMR spectroscopy. Quail IgY contained only neutral oligosaccharides of the following categories: the glucosylated oligomannose type (0.6% Glc alpha 1-3Glc alpha 1-3Man9GlcNAc2; 35.6%, Glc alpha 1-3Man7-9GlcNAc2). oligomannose type (15.0%, with the structure Man5-9GlcNAc2) and biantennary complex type with core structures of -Man alpha 1-3(-Man alpha 1-6)Man beta 1-4GlcNAc beta 1-4GlcNAc (9.9%), -Man alpha 1-3 (GlcNAc beta 1-4)(-Man alpha 1-6)Man beta 1-4GlcNAc beta 1-4GlcNAc (25.1%) and -Man alpha 1-3(GlcNAc beta 1-4)(-Man alpha 1-6)Man beta 1-4GlcNAc beta 1-4(Fuc alpha 1-6)GlcNAc (11.4%). Although never found in mammalian proteins, glucosylated oligosaccharides (Glc1Man7-9GlcNAc2) have been located previously in hen IgY.

Skin sympathetic nerve activity in acquired idiopathic generalized anhidrosis

We recorded skin sympathetic nerve activity (SSNA) microneurographically from the right tibial nerve of a patient with acquired idiopathic generalized anhidrosis (AIGA). The patient did not show any spontaneous sweating or pilocarpine- and nicotine-induced sweat response. Histopathologic examination showed degenerated eccrine glands associated with surrounding inflammatory cellular infiltration. Electrical nerve stimulation produced a two-peak pattern of SSNA reflex discharge representing sudomotor and vasoconstrictor components. The frequency of spontaneous SSNA bursts (burst rate), presumably of a sudomotor nature, at the ambient temperature of 25 degrees C was significantly higher than in a healthy control subject and was further increased at a temperature of over 38 degrees C. Thus, sudomotor sympathetic nerve activity is well preserved or even increased in AIGA. We conclude that anhidrosis of AIGA results from the generalized sweat gland dysfunction rather than decreased sympathetic outflow to the skin.

Human ERG-2 protein is a phosphorylated DNA-binding protein--a distinct member of the ets family

We describe the identification of the ERG-2 gene products using an antibody raised against recombinant human ERG-2 protein. ERG-2 is a nuclear phosphoprotein and binds to purine-rich sequences (C/G)(C/a)GG-AA(G/a)T. ERG-2 protein, with a half-life of 21 h, is considerably more stable than the short-lived ETS-1 or ETS-2 proteins. Its phosphorylation is stimulated by phorbol myristate acetate (PMA), but not by Ca2+ ionophore treatment. ETS-1 protein is phosphorylated by Ca(2+)-dependent events, whereas ERG-2 protein is phosphorylated by activation of protein kinase C, suggesting their involvement in distinct signal transduction mechanisms. The expression of ERG-2 protein is restricted to few cell types and is high in early myeloid cells, indicating that it may function at an early stage of hematopoietic lineage determination. The DNA-binding sequence for ERG-2 protein is identified by using a random oligonucleotide selection procedure. The selected sequence is very similar to the binding sequence determined for human ETS-1 using the same method. Like other ets proteins, ERG-2 is a sequence-specific DNA-binding protein and is expressed at higher levels in early myeloid cells than in mature lymphoid cells. These results suggest that it may act as a regulator of genes required for maintenance and/or differentiation of early hematopoietic cells.

[Developmental biotechnology and hypertension--emphasis on renin-angiotensin system]

The recent remarkable progress in molecular biology and developmental biotechnology has contributed to the evaluation of mechanism of hypertension. The renin-angiotensin system (RAS) is defined as an endocrine substance acting on blood pressure regulation. Accumulating evidence suggests the existence of tissue RAS in various organs, such as the brain, heart, vascular walls, adrenal gland, testis and ovary, in addition to the circulating RAS. However, it remains unclear how the RAS affects those tissues and high blood pressure. The advent of new developmental biotechnology gives an additional dimension to hypertension research. Such approach includes the generation of transgenic animals carrying the component of RAS genes and it should contribute to the elucidation of the RAS action in tissue function. In this manuscript, transgenic animals, produced to date, with emphasis on hypertension is introduced.

Activation of two angiotensin-generating systems in the balloon-injured artery

Participation of angiotensin II in the myointimal proliferation following a vascular injury was postulated. This study assessed the potential involvement of the local angiotensin II-forming enzymes in injured arteries of dogs. The potential angiotensin II-forming enzymes are angiotensin-converting enzyme (ACE) and chymostatin-sensitive angiotensin II-generating enzyme (CAGE) which is highly homologous to or could be identical to the mast cell chymase. Both ACE and CAGE catalyze the conversion of angiotensin I to angiotensin II. We found that the enzymatic activities of ACE and CAGE, and the mRNA levels of ACE and chymase were increased in the injury-induced hypertrophied vessels. The results suggest that ACE and CAGE participate in the hypertrophy through the production of angiotensin II which is a growth promoter for vascular smooth muscle cells.

Concomitant enhancement of the response to Mls-1a antigens and the induction of post-thymectomy autoimmune gastritis in BALB/c mice

We examined the role of Mls antigens in the induction of autoimmune gastritis (AIG) in BALB/c and DBA/2 mice subjected to thymectomy. The prevalence of AIG in Mls-1b mice which underwent thymectomy on day 3 after birth (3d-Tx) was 78% (mean), while in Mls-1a DBA/2 mice it was < 6%. Whereas AIG-negative 3d-Tx DBA/2 mice produced 2-mercaptoethanol (2-ME)-sensitive antiparietal cell autoantibody, AIG-positive BALB/c mice made 2-ME-resistant anti-parietal cell autoantibody. In addition, the prevalence of AIG in 3d-Tx BALB/c mice which were rendered tolerant to MIs-1a antigens by injection of bone marrow cells from (BALB/c x DBA/2)F1 mice within 24 h after birth was decreased compared with the non-tolerant control mice; the prevalence being 80% in the controls and 30% in the tolerant animals. Thus, the activation of helper T cells, including T cells responding to Mls-1a antigens and including immunoglobulin class switch, appeared to be closely associated with the induction of AIG. Flowcytometric analysis confirmed that CD4- V beta 6 T cells had increased in the regional lymph nodes of the stomach in AIG mice. However, an increase in the number of V beta 11 T cells, which are known to increase in 3d-Tx mice, occurred in the CD8, but not in the CD4 T cell population. Injection of MoAb to L3T4, but not Lyt2, V beta 6- or V beta 8-TCR, into 3d-Tx BALB/c and syngeneic nude mice which had received spleen cells of 3d-Tx BALB/c mice bearing AIG completely abrogated the development of AIG, despite there being remarkable decreases in T cells expressing relevant markers to the injected antibodies in all the mice. These findings suggest that the increase of V beta 6+ L3T4+ T cells in AIG mice was concomitant with the activation of AIG-inducing V beta 6- L3T4+ T cells.

Direct synaptic connections between thalamocortical axon terminals from the mediodorsal thalamic nucleus (MD) and corticothalamic neurons to MD in the prefrontal cortex

A combined anterograde axonal degeneration with ibotenic acid and wheat germ agglutinin-horseradish peroxidase (WGA-HRP) retrograde tracing study revealed that some degenerating thalamocortical axon terminals from the mediodorsal thalamic nucleus (MD) directly formed asymmetrical synaptic contacts predominantly with dendritic spines of apical dendrites of WGA-HRP-labeled corticothalamic projection neurons to MD in the prelimbic cortex of the rat. This result suggests that there is a monosynaptic feedback loop from and to MD via deeper layer neurons in the prelimbic cortex.

MRI of soft-tissue lesions: opposed-phase T2*-weighted gradient-echo images

We evaluated the ability of opposed-phase T2*-weighted gradient-echo (T2*GE) MRI to demarcate soft tissue lesions. The series contained 37 cases, including 18 benign tumors, 8 malignant tumors, and 11 miscellaneous nonneoplastic soft-tissue lesions. Images were obtained on a 0.5 T magnet with T2*GE imaging (TR/TE 300/22 ms, 20 degrees). Results were compared with those of T1-weighted SE images (500/20-40) and T2-weighted SE (T2SE) images (2,000/80). The T2*GE images were similar to T2SE images with respect to the signal behavior and internal architecture of the masses in many cases. In some instances, they were better than T2SE images in delineating the lesions and adjacent fat tissue, in delineating the lesions and adjacent small vessels, and in depicting special features such as hemosiderin deposits. They were inferior to T2SE images in delineating the lesions and adjacent muscles. Because of reduced lesion-muscle delineation, T2*GE images can not be substituted for T2SE images in the evaluation of soft-tissue lesions, but are useful as an adjunct in some cases.

Species differences in binding of submandibular nuclear proteins to renin promoter DNA

1. Renin is highly expressed in submandibular gland (SMG) of mouse, which has two genes, Ren-1d and Ren-2d, but not at all in rat SMG. Differences in nuclear protein binding to renin promoter DNA were, therefore, explored. 2. Rat -169 to +23 renin DNA formed complexes with both mouse and rat extract, whereas a corresponding fragment of mouse Ren-1d DNA (-121 to +4) bound with rat extract, but much less so with mouse extract. Rat extract bound a -704 to -450 fragment of the Ren-1d promoter. For Ren-2d -578 to -383 and -786 to -718 DNA bound with mouse extract and -383 to +11 and -664 to -578 DNA bound with rat extract. 3. The results support a role for differences in presence or binding of species-specific trans-acting factors in the differential regulation of the renin gene in SMG of mouse and rat. Strong binding near the rat RNA polymerase II binding site could repress transcription in rat SMG, and binding peculiar to the Ren-2d B2 element might contribute to high expression in mouse SMG.

Satisfactory separation and MS-MS spectrometry of six surfactins isolated from Bacillus subtilis natto

We optimized HPLC conditions for the first time to achieve satisfactory separation of six surfactins, two of which were novel, isolated from Bacillus subtilis natto. Peptide sequences were analyzed by sophisticated MS-MS analysis, performed with a pair of two surfactins with different fatty acid substitutions. Fragment peaks were divided into two series; one was a series of the ions which carried fatty acid, and thus were characterized by the fatty acid mass difference, and the other was a series of the ions which consisted of pure peptide and thus showed a superimposable pattern between a pair of surfactins.

Osmophilic linear plasmids from the salt-tolerant yeast Debaryomyces hansenii

Three novel linear plasmids, pDHL1 (8.4 kb), pDHL2 (9.2 kb) and pDHL3 (15.0 kb), were discovered in the halophilic (salt-tolerant) yeast Debaryomyces hansenii. Exonuclease treatment indicated that all three plasmids were blocked at their 5' ends, presumably, by analogy with most other eukaryotic linear plasmids which involved protein attachment. The Debaryomyces plasmids were entirely cured simply by growing cells in normal culture medium, but were stably maintained in culture medium containing salts, sorbitol or glycerol at suitable concentrations. This suggested that the pDHL plasmids required an osmotic pressure for stable replication and maintenance. The Debaryomyces yeast secreted a killer toxin against various yeasts species. Toxin activity was demonstrated only in the presence of salts such as NaCl or KCl, but this killer phenotype was not associated with the pDHL plasmids. Analysis of the plasmid-curing pattern suggested that pDHL3 may play a key role in the replication of the Debaryomyces plasmids. Southern hybridization showed that an extensive homology exists between specific regions of pDHL1 and pDHL2, whereas pDHL3 is unique.

Possible roles of the 3'-flanking sequences of the human activin beta A subunit gene in its expression

Tumor promoter 12-O-tetradecanoylphorbol-13-acetate stimulates an increase in erythroid differentiation activity in human fibrosarcoma HT1080 cells. Here, we demonstrate that this process involves a rapid accumulation of five species of activin beta A/erythroid differentiation factor mRNA, followed by protein kinase C activation, and that variation in size of the activin transcripts is due to multiple 3' ends, presumably reflecting an alternative polyadenylation. In transiently transfected HT1080 cells, a 97-bp DNA fragment containing an AP-1 consensus sequence (TGAGTCA) located in the 3'-flanking region of the activin gene was capable of activating the heterologous herpes simplex virus thymidine kinase (tk) and SV40 early promoters, and a cotransfected c-Jun enhanced these fusion promoter activities. The deletion of TGAG sequences from the AP-1 element in the 97-bp DNA sequence context abolished its c-Jun-mediated activation from the tk promoter even in HT1080 cells overexpressing stably transfected c-Jun. Cotransfected adenovirus E1A products repressed the tk promoter activity enhanced by the activin AP-1 element itself or in concert with transiently transfected c-Jun, indicating that the putative AP-1 sequence acts as an activator element, depending upon c-Jun activity. These results suggest that the 3'-flanking DNA sequences of the human activin beta A subunit gene play an important role in its expression.

Biochemical properties of amphibian bone morphogenetic protein-4 expressed in CHO cells

The biochemical properties of recombinant amphibian bone morphogenetic protein-4 (BMP-4), the cDNA of which has been cloned recently by screening of a Xenopus cDNA library, was characterized. The protein was expressed by the transfection of Chinese hamster ovary (CHO) cells with the cDNA cloned into expression vectors bearing a cytomegalovirus promoter or a simian virus 40 promoter. Northern-blot analysis showed that the latter vector was more efficient for Xenopus BMP-4 expression. Specific antiserum against Xenopus BMP-4 peptide demonstrated that the protein is synthesized as a large precursor, processed to the mature form and then secreted from the cells as a homodimer. Analysis of the biological activity in the conditioned medium revealed that Xenopus BMP-4 has a potent alkaline phosphatase-inducing activity on mouse osteoblastic cells.

A potent anti-metastatic activity of tumor invasion-inhibiting factor-2 and albumin conjugate

Tumor invasion-inhibiting factor-2 (IIF-2) peptide was chemically conjugated to albumin with 1-ethyl-3(3-dimethylaminopropyl)-carbodiimide hydrochloride. The molar ratio of the covalently linked IIF-2 peptide and albumin in the purified conjugate was 1.4 +/- 0.4, as determined with a radioactive peptide. The conjugate inhibited the invasion of HT1080 and B16FE7 cells in vitro at 40- to 60-fold lower concentrations than IIF-2 peptide. Scatchard analysis of binding data demonstrated that the IIF-2-albumin conjugate bound to HT1080 and B16FE7 cells with Kd values of 240 and 340 nM, respectively. The conjugate suppressed the lung colonization of B16FE7 cells more effectively than the IIF-2 peptide in an experimental metastasis. These results indicate that the covalent linkage of the IIF-2 peptide to a carrier macromolecule provides a structure that enables this peptide to exhibit increased inhibitory action in cancer cell invasion and metastasis, and that IIF-2 exerts its inhibitory action on invasion by binding to a specific binding site on the tumor cell surface.

Positional and additive effects of basic amino acids on processing of precursor proteins within the constitutive secretory pathway

We have recently shown that the Arg/Lys-X-Lys/Arg-Arg or Arg/Lys-X-X-X-Lys/Arg-Arg sequence serves as a signal for cleavage of precursor proteins within the constitutive secretory pathway, and this cleavage is catalyzed by furin, a mammalian homolog of the yeast Kex2 protease. In this study, we further examined sequence requirements for the constitutive precursor cleavage. Based on the data concerning cleavage efficiencies of various prorenin mutants with amino acid substitution(s) around the native cleavage site expressed in CHO cells, we revised the sequence rules that govern the constitutive cleavage as follows: (i) the Arg residue at position -1 is essential; (ii) in addition to the Arg at position -1, at least two out of the three basic residues at positions -2, -4, and -6 are required for efficient cleavage (the presence of all the three basic residues results in most efficient cleavage); (iii) at position +1, a hydrophobic aliphatic amino acid is not suitable.