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F Sugiyama

Publications and source records attributed to F Sugiyama.

At least 55 records · Page 3Linked to original sources
PubMed1995

Heritable formation of neuroectodermal tumor in transgenic mice carrying the combined E1 region gene of adenovirus type 12 with the deregulated human renin promoter.

Adenovirus early 1 (E1) region gene products, including E1A and E1B, are required for transcriptional regulation of viral and cellular promoters in infected and transfected culture cells and for transformation of primary rodent cells. Here, we established a line of transgenic mice carrying the E1 region gene of human adenovirus type 12 under the control of the human renin promoter, in which a neuroectodermal tumor derived from retroperitoneal, olfactory, and/or pelvic regions was heritably developed with varying degrees of incidence and the phenotype was successfully passed through six generations. The transgenes were located in the region E2-E3 bands of chromosome 7 with which no genetic linkage to neuroectodermal tumors was previously demonstrated, and expressed only in the tumors but not in another tissue examined. Notably, in addition to the expression of a neural marker gene N-CAM, the three nuclear oncogenes, c-, L-, and N-myc, were coexpressed in the tumors. These results suggest that E1A and E1B are cooperatively involved in the heritable formation of neuroectodermal tumors associated with co-expression of the three sets of myc family genes.

Adenovirus E1 Proteins↗
PubMed1995

Activation of the nuclear oncogenes N-myc and c-jun in carcinoid [correction of cartinoid] tumors of transgenic mice carrying the human adenovirus type 12 E1 region gene.

The adenovirus (Ad) E1 region genes, E1A and E1B, are well known cooperatively to transform primary rodent cells and activate a number of cellular promoters, including nuclear oncogenes such as N-myc and c-jun, in transfected cell lines. However, there is still less information available on the in vivo mechanism(s) by which the E1 region gene, when chromosomally integrated in the living animals, exerts its effect on nuclear oncogene activation coupled with transformation. To investigate such in vivo activity of E1A we have used a series of microinjection experiments into fertilized eggs to generate three transgenic mice carrying the Ad12-type E1A/E1B genes under the control of the human renin gene. This transgene caused an early onset of bowel cartinoid tumors that express neural cell adhesion molecules, but do not metastasize to any region. Northern blot analysis revealed that the transgenes were considerably expressed in the tumors, but not in other tissues at detectable levels. Interestingly, the levels of N-myc and c-jun mRNAs in the cartinoid tumors were elevated 19- and 8-fold, respectively, as compared with those found in the control intestine. In contrast, the major histocompatibility complex (MHC) class I mRNA level was not altered between the tumor and control intestines, suggesting that this unchanged expression may reflect the loss of tumor metastasis. These findings provide the first in vivo evidence that the expression of the Ad12 E1 region gene induces cartinoid tumors associated with the activation of the nuclear oncogenes N-myc and c-jun.

Adenovirus E1 Proteins↗
PubMed1994

Angiotensinogen-deficient mice with hypotension.

The renin-angiotensin system is an enzymatic cascade that produces a potent vasoconstrictor octapeptide angiotensin II, through its physiologically inactive intermediate decapeptide angiotensin I, from their precursor angiotensinogen. In the present study, we generated angiotensinogen-deficient mice by homologous recombination in mouse embryonic stem cells. These mice do not produce angiotensinogen in the liver, resulting in the complete loss of plasma immunoreactive angiotensin I. The systolic blood pressure of the homozygous mutant mice was 66.9 +/- 4.1 mm Hg, significantly lower than that of wild-type mice (100.4 +/- 4.4 mm Hg). This profound hypotension in angiotensinogen-deficient mice demonstrates an indispensable role for the renin-angiotensin system in maintaining blood pressure.

Angiotensin I↗
PubMed1994

Neuroectodermal tumors expressing c-, L-, and N-myc in transgenic mice that carry the E1A/E1B gene of human adenovirus type 12.

Adenovirus early 1 (E1) region gene products, including E1A and E1B, are required for transformation of primary cultured rodent cells. In order to investigate in vivo action of the E1 region, we established a line of transgenic mice carrying the oncogenic E1A and E1B genes of human adenovirus type 12 under control of the human angiotensinogen promoter. Histopathological analyses indicated that transgenic mice heritably develop neuroectodermal tumors arising from the pelvic region with varying degrees of incidence. The transgene was expressed in the neuroectodermal tumors as well as in TNT-1 cells, a cell line established from the tumors, where the human angiotensinogen promoter was constitutively active. The high level expression of c-, L-, and N-myc without gene amplification was notable in the original tumors and TNT-1 cells, but not in another tissue examined. The co-expression of the three sets of myc family genes in both the original tumors and the established cell line provided the possibility that the target cells for transformation may belong to a specific cell type that expresses all these oncogenes during development.

3T3 Cells↗
PubMed1994

Tissue-specific trans-activation of renin gene by targeted expression of adenovirus E1A in transgenic mice.

We generated two transgenic mice carrying the adenovirus type 12 E1 region genes under control of the human renin promoter, in which the E1A and E1B genes were expressed predominantly in the kidney. Interestingly, renal transcription of the gene for mouse renin was shown to be elevated at 28 and 40 folds as compared in those of control animals, but histone mRNA levels were unchanged. Although the transfected mouse renin promoter was promiscuously trans-activated by E1A in HeLa cells where the endogenous renin gene was silent, the transgenic studies suggested that a cellular factor(s), in addition to E1A, was required for the tissue-specific renin gene activation. These findings provide the in vivo evidence that E1A could trans-activate cellular gene transcription in a tissue-specific manner.

Adenovirus E1A Proteins↗
PubMed1994

Cortical expression of the human angiotensinogen gene in the kidney of transgenic mice.

We have previously generated "Tsukuba hypertensive mice" with elevated blood pressure by cross-mating separate lines of transgenic animals carrying either 15 kb of the human renin gene including its native 3-kb promoter or 14 kb of the human angiotensinogen gene along with its 1.3-kb promoter, the former of which is expressed predominantly in the kidney and the latter of which is also expressed in the kidney to levels comparable to those found in the liver. To investigate whether the integrated human angiotensinogen gene is prominently expressed in the kidney of transgenic mice, we have analyzed a production region of the transgene mRNA by in situ hybridization technique. This analysis clearly demonstrated that human angiotensinogen mRNA is localized specifically to the cortex region of transgenic mouse kidney. The present finding indicates a possible involvement of the renal renin-angiotensin system in the pathogenesis of high blood pressure in transgenic mice.

Angiotensinogen↗
PubMed1994

Species-specific expression of the hepatic renin gene.

The catalytic reaction of renin, an aspartyl proteinase, with angiotensinogen is the rate-limiting step fo the renin-angiotensin system involved in the maintenance of blood pressure and electrolyte balance in mammals. We have characterized species-specific expression of the hepatic renin gene by RNase protection experiment, primer extension analysis, and promoter assay using an in vitro DNA transfection. RNase protection experiments revealed that the renin gene is expressed in rat liver, but neither in mouse nor in human. Primer extension analysis identified the putative promoter region of the rat renin gene, which contains TATAAAA sequence, a canonical regulatory DNA element. In order to test whether the upstream region of the renin gene with respect to the putative transcription initiation site is a functional promoter, we have examined the ability of the 5'-flanking sequences of the rat renin gene as well as the human and mouse genes to activate expression of a reporter gene containing the bacterial chloramphenicol acetyltransferase (CAT)-coding sequences, by transient transfection assays. In transfected HepG2 cells, a hepatoma cell line, only the rat renin promoter was capable of driving the CAT gene expression. These results suggested that the rat-specific renin gene expression in the liver could be primarily determined by its promoter specificity.

Animals↗
PubMed1993

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.

Angiotensin I↗
PubMed1993

Neurotropism of mouse-adapted haemagglutinating encephalomyelitis virus.

The propagation of a mouse-adapted strain (67N) of haemagglutinating encephalomyelitis virus in infected mice and murine cells was examined by viral re-isolation and immunostaining. Viral propagation was strictly limited to the neurons and to an established line of neuroblastoma cells in in-vivo and in-vitro experiments. These results provide adequate evidence that this virus is neurotropic.

Animals↗
PubMed1993

Comparative study on cross-reaction of leptospiral antibodies in several serological tests to detect antibodies to Borrelia burgdorferi in dogs.

The effects by the leptospiral antibody are described at several serological tests for the detection of the antibody to B. burgdorferi in dogs. The titers at ELISA used with the ultrasonicated bacterial antigen (US-ELISA) were related with IFA. But cross reaction with the leptospiral antibody were shown in an agglutination test. Non-specific and cross-reactions were observed in ELISA used with formalin-killed bacterial antigen. This indicates that US-ELISA is a reliable serodiagnosis method for Lyme disease in dogs in eliminating the cross reaction with leptospiral antibody.

Agglutination Tests↗
PubMed1993

Rat renin promoter activity in cultured cells and transgenic mice.

Renin, a key enzyme controlling blood pressure, is mainly synthesized in kidney. To characterize the rat renin promoter, we have constructed a reporter gene containing the 238-bp putative regulatory region linked to a bacterial chloramphenicol acetyltransferase (CAT), and analyzed its promoter activity by in vitro transfection and introduction of the CAT fusion gene into germline of mice. CAT activity was detected in transfected embryonic kidney-derived 293 cells, but not in HeLa cells derived from cervical carcinoma, showing that the putative promoter region of the rat renin gene directs transcription in a cell type-dependent manner. To examine whether the sequence was sufficient to regulate the expression of the CAT chimeric gene in mice, we generated seven transgenic mice carrying the reporter construct. Unexpectedly, the transgene was not expressed in any of the independent transgenic mice examined. These results suggest one possibility that an additional control region may be required for efficient expression of the rat renin promoter in developing mice.

Animals↗
PubMed1993

Comparison of plasma endotoxin levels in germ-free, SPF and conventional laboratory animals (mice and rats).

Plasma endotoxin levels were examined in laboratory mice and rats sustained under germ-free (GF), SPF and conventional (CV) conditions. The values were 1.72 (GF mouse), 2.67 (SPF mouse), 2.44 (CV mouse), 2.05 (GF rat), 2.56 (SPF rat), and 3.13 pg/ml (CV rat). The GF animals showed the lowest levels, followed by SPF and CV animals, in that order. When SPF animals were transferred into the conventional condition (conventionalization), the plasma endotoxin levels changed slightly, but not significantly. The present study demonstrates that the levels of plasma endotoxin in healthy laboratory animals are relatively stable and are not affected by microbiological conditions.

Animals↗
PubMed1993

[Comparison between the blood from orbital sinus and heart in analizing plasma biochemical values--increase of plasma enzyme values in the blood from orbital sinus].

Plasma biochemical values, blood urea nitrogen (BUN), glucose, aspartate aminotransferase (AST), lactate dehydrogenase (LDH) and creatine phosphokinase (CPK), were compared between the samples collected from orbital sinus, heart and tail vein in mice, rats and hamsters. The significant higher values of AST, LDH and CPK were shown in samples from orbital sinus as compared with that from other sites. The blood from orbital sinus was bleeding by two methods and compared in the plasma enzyme values. It is suggested that the leakages of these enzymes from destroyed ocular tissues result in the increase of the plasma enzyme values.

Animals↗
PubMed1993

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.

Animals↗
PubMed1993

Isolation of Salmonella from impounded dogs introduced to a laboratory.

Isolation of Salmonella from the feces of impounded dogs was carried out to make clear the recent microbiological condition of dogs introduced into our facilities. Salmonella was isolated from 10 out of 283 samples (3.5%). Inparticular, during the first week after introduction, Salmonella was isolated from nine out of 74 dogs (12.2%). The isolation rate during the first week after introduction was significantly higher than that for dogs introduced later. No isolates were detected from dogs reared for more than 3 weeks after introduction. This study indicates that impounded dogs had the highest risk of infecting a person with Salmonella during the first week after introduction into our laboratory animal facilities, and that we need to pay attention to this fact when handling them.

Animals↗