[Progress of gastrin research--from gene to big gastrin N-terminal fragment].
Explore the source record for details and available documents.
Amino Acid Sequence↗
Biomedical subjects
S Tarui
Publications and source records attributed to S Tarui.
Establishment and characterization of a new human B-cell line (ONHL-1) from non-Hodgkin's lymphoma: constant expression of bcl-2 gene during mitogen-induced growth inhibition.
A new B-cell line (ONHL-1) was established from non-Hodgkin's lymphoma. ONHL-1 was free from Epstein-Barr virus nuclear antigen and expressed CD20, CD24, and slg (mu, delta, gamma and kappa), thus being equivalent to the mature B-cell stage. Chromosome analysis revealed a markedly abnormal pattern including 14q+ and 6q-. In accordance with the positive expression of surface kappa light chains, one of the kappa genes was found to be rearranged. However, rearrangement of the lambda locus was also detected, contrary to the supposed hierarchy for the rearrangement of the light-chain genes. Further, the rearranged fragments of the JH, C lambda, and bcl-2 genes were of the same size in the EcoRI and HindIII digests on the same filter. This may suggest that the bcl-2 gene is juxtaposed with the JH and C lambda locus. The proliferation of ONHL-I was inhibited by adding Staphylococcus aureus Cowan 1 or 12-O-tetradecanoyl-phorbol-13-acetate. During this growth inhibition, the expression of c-myc decreased, while that of bcl-2 mRNA remained steady. This result suggests that not the bcl-2 gene but other oncogenes, such as c-myc, play a key role in the proliferation of ONHL-1. This agrees with the hypothesis that the bcl-2 gene is not concerned with aggressive proliferation but with cell survival. This new cell line will therefore be of value in studying the differentiation and tumorigenesis of B cells.
Cell Division↗
Proliferative potential of murine peritoneal mast cells after degranulation induced by compound 48/80, substance P, tetradecanoylphorbol acetate, or calcium ionophore A23187.
Proliferative potential of degranulated mast cells was investigated. Mast cells were collected from the peritoneal cavity of mice, and degranulation was induced by compound 48/80, substance P, 12-O-tetradecanoylphorbol 13-acetate (TPA), or calcium ionophore A23187. The potentiality of colony formation in methylcellulose was not reduced by treatment of various concentrations of compound 48/80, substance P and TPA. When degranulation was induced by compound 48/80, substance P or TPA, proportion of highly degranulated mast cells containing less than five granules was rather small. In contrast, considerable proportion of highly degranulated mast cells was obtained after the treatment with the low concentration (0.1 microgram/ml) of A23187. These highly degranulated mast cells, which were individually picked up by the micromanipulator, proliferated not only in methylcellulose but also in the skin of mast cell-deficient WBB6F1-W/Wv mice. Inasmuch as we have already shown the proliferation of IgE-sensitized and Ag-stimulated mast cells, degranulated mast cells appear to retain the proliferative potential in general.
Animals↗
Modulation of N-acetylglucosaminyltransferase III, IV and V activities and alteration of the surface oligosaccharide structure of a myeloma cell line by interleukin 6.
The activity of N-acetylglucosaminyltransferase (GnT) III, IV and V on a myeloma cell line, OPM-1, was examined after incubation with interleukin 6 (IL-6). While augmenting cell proliferation, IL-6 resulted in a decrease of GnT III activity and an increase of GnT IV and V activities. Consistent with this, OPM-1 cultured with IL-6 showed an increased affinity to Datura stramonium lectin, which recognizes asialo-tri- and asialo-tetraantenary N-linked oligosaccharides. These results indicate that IL-6 modulates glycosyltransferase activity and the oligosaccharide structure of target cells.
Cell Membrane↗
Purification of N-terminal hexapeptide of big gastrin from human urine.
We previously demonstrated that extremely high amounts of N-terminal big gastrin (G-34) fragments are excreted in human urine and three of them are N-terminal octa-, nona-, and decapeptide of G-34. Our subsequent examination revealed that there exists a considerable amount of another N-terminal G-34 fragment in urine, less hydrophobic than the three peptides. We purified this fragment from urine of an achlorhydric patient and determined the structure: less than Glu-Leu-Gly-Pro-Gln-Gly. The purification was carried out by Sep-Pak C18 cartridges, Sephadex G-25, and reverse phase HPLC. The structure was determined by a combination of amino acid analysis, amino acid sequence analysis, and mass spectral analysis. N-terminal hexapeptide of G-34 is the second richest component of urinary N-terminal G-34 fragments next to N-terminal octapeptide of G-34 in normal subjects.
Achlorhydria↗
Hypocholesterolaemic factor from gallbladder cancer cells.
A patient is reported with drug-resistant familial hypercholesterolaemia in whom serum cholesterol fell after the onset of gallbladder cancer with intraperitoneal invasion. Cancer cells were obtained from ascitic fluid and a cultured cell line established. Incubation of the culture medium of these cells with skin fibroblasts from the patient and from normal subjects increased low-density lipoprotein (LDL) receptor activity in a dose-dependent manner. These results show that gallbladder cancer cells from this patient secrete a substance that stimulates LDL receptor activity. This substance may have contributed towards reduction of serum cholesterol.
Adenocarcinoma↗
Effects of phorbol ester on cell growth inhibition by transforming growth factor beta 1 in human hepatoma cell lines.
The effects of phorbol ester on cell growth inhibition by transforming growth factor beta 1 (TGF-beta 1) in human hepatoma cell lines, Mahlavu and PLC/PRF/5, were investigated. TGF-beta 1 (2.5 to 10 pM) alone could not inhibit the growth of Mahlavu cells, whereas in the presence of 12-O-tetradecanoyl phorbol 13-acetate (TPA) at 1 ng/ml, TGF-beta 1 could suppress their growth in a dose-dependent manner. The growth of PLC/PRF/5 cells could be inhibited by addition of TGF-beta 1 (2.5 to 10 pM) alone in a dose-dependent manner, and this action was not affected by TPA (1 ng/ml). The TGF-beta 1 inhibition induced by TPA in Mahlavu cells could not be cancelled by addition of protein kinase C inhibitor, 1-(5-isoquinolinesulfonyl)-2-methylpiperazine (H7) (10 microM) or staurosporin (1 nM). Thus, TPA could induce TGF-beta 1 inhibition of cell growth in Mahlavu cells which did not respond to TGF-beta 1 alone, and activation of protein kinase C does not seem to be behind this TPA action.
1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
Total deficiency of plasma cholesteryl ester transfer protein in subjects homozygous and heterozygous for the intron 14 splicing defect.
The molecular basis of cholesteryl ester transfer protein (CETP) deficiency was investigated in 4 unrelated CETP-deficient families. The high density lipoprotein-cholesterol levels of the probands exceeded 150 mg/dl. The plasma of the probands was totally deficient in CETP activity and mass. The genomic DNA of the patients was amplified by polymerase chain reaction, using two oligonucleotide primers located in the intron 12 and 14 of the CETP gene, and the amplified products were directly sequenced. Two patients were homozygous for a G-to-A change at the 5'-splice donor site of the intron 14. The G-to-A change would cause impaired splicing of pre-messenger RNA. The other two probands were heterozygous for the mutation, but totally lacked CETP. Their lipoprotein patterns were also similar to those of the two homozygotes. Thus, other genetic defects or metabolic factors influencing CETP expression are implicated. The data suggest that the G-to-A mutation may be common in human plasma CETP deficiency. Furthermore, there could be compound heterozygotes who totally lack plasma CETP and have lipoprotein profiles similar to those of homozygotes.
Adult↗
Two novel variants of transthyretin identified in Japanese cases with familial amyloidotic polyneuropathy: transthyretin (Glu42 to Gly) and transthyretin (Ser50 to Arg).
Two mutant genes coding for two different variants of transthyretin were identified in two independent kindreds with familial amyloidotic polyneuropathy. A single base change from A to G was identified in exon 2 of transthyretin gene in two brothers from the first kindred. This base change led to replacement of glutamate by glycine at position 42 of 127-residue molecule. In a patient from the second kindred, T to G transversion in exon 3 of transthyretin gene led to replacement of Ser by Arg at position 50. The two mutants were discovered by randomly sequencing recombinant clones containing the entire length of each one of the four exons selectively amplified by polymerase chain reaction. The base change produced a new restriction site for Hae III and Cfr 13 I in the exon 2 and for Mva I in the exon 3, respectively. Restriction fragment length polymorphisms and allele-specific oligonucleotide hybridizations confirmed the base changes. The accurate detection of the new mutant genes is hereafter possible by these procedures.
Alleles↗
Genetic defect in muscle phosphofructokinase deficiency. Abnormal splicing of the muscle phosphofructokinase gene due to a point mutation at the 5'-splice site.
The genetic defect in muscle phosphofructokinase deficiency (type VII glycogenosis, Tarui disease) was investigated. Six cDNAs for muscle phosphofructokinase, including a full-length clone, were isolated from a non-amplified library of muscle from a patient. By sequence analysis of these clones, a 75-base in-frame deletion was identified. The rest of the sequence was identical to that of the normal cDNA, except for a silent base transition at position 516 (ACT (Thr) to ACC (Thr]. The deletion was located in the 3'-terminal region of exon 13 (numbered with reference to the rabbit muscle phosphofructokinase gene (Lee, C.-P., Kao, M.-C., French, B.A., Putney, S.D., and Chang, S.H. (1987) J. Biol. Chem. 262, 4195-4199]. Genomic DNA of the patient was amplified by polymerase chain reaction. Sequence analysis of the amplified DNA revealed a point mutation from G to T at the 5'-end of intron 13. This mutation changed the normal 5'-splice site of CAG:GTATGG to CAG:TTATGG. A cryptic splice site of ACT:GTGAGG located 75 bases upstream from the normal splice site was recognized and spliced in the patient.
Base Sequence↗
Increase in the active form of 3-hydroxy-3-methylglutaryl coenzyme A reductase in human hepatocellular carcinoma: possible mechanism for alteration of cholesterol biosynthesis.
3-Hydroxy-3-methylglutaryl coenzyme A reductase activity and the rate of sterol biosynthesis are positively correlated with DNA synthesis and proliferation of mammalian cells. The total (active plus latent) activity of 3-hydroxy-3-methylglutaryl coenzyme A reductase and the activity of its active form in hepatocellular carcinoma (HCC) from seven patients were measured and compared with those in liver tissue from five control subjects. The activity of the active form in HCC was 61 +/- 21 (SD) pmol/min/mg microsomal protein, while it was only 17 +/- 9.8 pmol/min/mg protein in the liver tissue from the controls; the difference was significant (P less than 0.005). The total activity of the reductase was also higher in HCC although the difference was not significant. The microsomal contents of the enzyme protein also were not significantly different. The rate of cholesterol biosynthesis was 307 +/- 81 pmol/h/mg tissue in HCC and 79.6 +/- 52 in normal liver tissue, indicating a significant increase in the rate in HCC (P less than 0.001). Thus, enhanced synthesis of cholesterol in human HCC seems to result partly from an increase in the active form of the reductase.
Carcinoma, Hepatocellular↗
A novel variant of transthyretin (Tyr114 to Cys) deduced from the nucleotide sequences of gene fragments from familial amyloidotic polyneuropathy in Japanese sibling cases.
A to G transversion was identified in exon 4 of transthyretin gene in familial amyloidotic polyneuropathy in two sibling cases living in Osaka. This transversion led to the replacement of tyrosine by cysteine residue at codon 114 of 127 residue molecule. This identification was achieved by randomly sequencing recombinant clones containing the entire length of each one of the four exons selectively amplified by polymerase chain reaction. Dot blot analysis with allele-specific oligonucleotides indicated the linkage of this mutation with the disease and confirmed the single base change.
Adult↗
Decreased xanthine oxidase activities and increased urinary oxypurines in heterozygotes for hereditary xanthinuria.
Two brothers with hereditary xanthinuria (xanthine oxidase deficiency) and several members of their family were studied. In both subjects, plasma and urinary concentrations of uric acid were low whereas xanthine and hypoxanthine concentrations were markedly elevated. Xanthine oxidase activity was virtually absent in the patients' duodenal mucosa, a finding that established the diagnosis of hereditary xanthinuria. In their parents (obligate heterozygotes), the duodenal xanthine oxidase activity was about 50% of that in control subjects (father 9.3 and mother 12.8 mU/g tissue compared with 21.3 +/- 5.0 mU/g tissue, mean +/- SD). The residual xanthine oxidase from the parents exhibited normal kinetics with respect to hypoxanthine. The parents' urinary xanthine and hypoxanthine concentrations were significantly greater than those of control subjects, while their plasma concentrations of oxypurines were normal. Similar findings were observed in at least 6 other relatives, a finding that suggested that they were heterozygotes. This study suggests that obligate hereditary xanthinuria heterozygotes have only 50% of the xanthine oxidase activity of controls; this deficiency results in a partial metabolic blockage at this enzymatic step in heterozygotes.
Adult↗
Evidence for alternative RNA splicing and possible alternative promoters in the human muscle phosphofructokinase gene at the 5' untranslated region.
Three mRNA species for human muscle phophofructokinase containing heterogeneous 5' untranslated sequences were identified through cDNA cloning. Type A mRNA was essentially the same as that reported previously (Nakajima, H., et al. (1987) FEBS Lett. 223, 113). Type B mRNA was considered to be the major gene product, which contained an extra non-coding sequence within the 5' untranslated region of type A mRNA. Amplification of mRNA by polymerase chain reaction revealed that types A and B mRNAs shared a common precursor RNA, and were alternatively spliced. Type C mRNA, homologous to the cDNA sequence from a placenta library (Sharma, P. M. et al., (1989) Gene 77, 177), was considered to be under the control of an alternative promotor.
Base Sequence↗
Immune pathogenesis of diabetes in the nonobese diabetic mouse: an overview.
Explore the source record for details and available documents.
Animals↗
Alterations in neocortical expression of nicotinic acetylcholine receptor mRNAs following unilateral lesions of the rat nucleus basalis magnocellularis.
We investigated the effect of a unilateral lesion of the nucleus basalis magnocellularis (nbm) on the expression of nicotinic acetylcholine receptors (nAChRs) in the rat cerebral cortex. Cortical nAChR concentration as determined by [3H]nicotine binding was unaffected by the nbm lesion. Expression levels of nAChR subunit mRNAs were measured using cDNA clones coding for the receptor subunits, alpha-3, alpha-4, and beta-2. At 1 week postlesion, expression levels of alpha-4, and beta-2 were increased by an average of 82% and 19%, respectively. On the other hand, expression levels of these mRNAs on the lesioned side 4 weeks after lesioning did not differ from those on the control side. Expression of alpha-3 was not altered by the nbm lesion. These results imply regulation of nAChR transcripts by cell to cell interactions. Co-increase of alpha-4 and beta-2 transcripts may provide supporting evidence for the occurrence of supersensitivity in deafferentated cholinergic neurons.
Animals↗
Demonstration of high-affinity interleukin-2 receptors on B-chronic lymphocytic leukemia cells: functional and structural characterization.
Functional and structural characteristics of interleukin 2 (IL-2) receptors on B-cell chronic lymphocytic leukemia (B-CLL) cells were analyzed by a proliferation assay, IL-2 binding assay and cross-linking study. In the 3H-thymidine incorporation assay, purified B-CLL cells from four out of sixteen cases, in which the percentage of Tac antigen (Tac Ag) positive cells in peripheral blood lymphocytes ranged from 0 to 48.8%, responded to IL-2 (100 U/ml) after both 3- and 6-day incubation. No relationship was found between the responsiveness to IL-2 and the percentage of Tac Ag positive cells. In the radiolabeled IL-2 binding assay, however, B-CLL cells from all seven cases examined, including three cases with mitogenic response to IL-2 and four cases without mitogenic response, were shown to have both high- and low-affinity receptors. The number of high- and low-affinity receptors per cell ranged from 29-186 and from 420 to 1,800, respectively. Furthermore, with the affinity cross-linking method p55 (Tac Ag) and p70/75 were found even in cases without mitogenic response in their B-CLL cells. In conclusion, the B-CLL cells so far examined possessed high-affinity IL-2 receptors consisting of p55 and p70/75; nevertheless, this was not sufficient to respond to the mitogenic signal of IL-2.
B-Lymphocytes↗
NH2-terminal big gastrin immunoreactivity in human urine.
The concentrations and molecular forms of urinary and plasma gastrin from normal subjects were studied by radioimmunoassays using two region-specific antisera. Urinary concentration of NH2-terminal big gastrin (G-34) immunoreactivity was several hundred times as great as that of COOH-terminal gastrin immunoreactivity. Fractionation of urine extract showed a broad giant peak of NH2-terminal G-34 immunoreactivity (gastrin fragments "U") eluting in a later position than G-34(1-17) by Sephadex G-50 column chromatography. HPLC revealed that urinary NH2-terminal G-34 immunoreactivity was composed of four fragments including G-34(1-8), G-34(1-9), and G-34(1-10). Sephadex G-50 column chromatography of plasma extract revealed two or three peaks of NH2-terminal G-34 immunoreactivity, and a major peak eluted in the same position as urinary gastrin fragments "U". These results and data on renal clearances suggest that most of all gastrin fragments "U" in plasma are excreted in urine without renal reabsorption, whereas almost all of plasma COOH-terminal gastrin peptides including G-34 and little gastrin (G-17) are removed and metabolized in the kidney.
Adult↗