[Analysis of proliferating cell nuclear antigen (PCNA) expression in brain tumors]

The expression of PCNA in brain tumor cells was measured in vitro and in situ by using an electrophoretical immunoblotting method and an immunohistochemical staining method. In synchronized C6 rat glioma cells, PCNA were almost parallel to the S phase, although the small amounts of PCNA were expressed in G1 and G2 x M phases. In astrocytic tumors from operative tissues, immunohistochemical PCNA positive rate increased significantly with increasing tumor grade. PCNA positive rate of recurrent meningiomas was also significantly higher than that in nonrecurrent meningiomas. These findings suggest that the PCNA is associated with the cell cycle, especially the S phase and immunohistochemical staining of PCNA is useful to evaluate the proliferating activity of a brain tumor. Immunoblotting method would also be helpful for the exact analysis of proliferating activity in brain tumor cells.

Isolation and mapping of a novel human gene encoding a protein containing zinc-finger structures

We have isolated and characterized a cDNA clone, termed OTK18, representing a novel human gene. The 3754 nucleotides of this clone contain an open reading frame of 2133 nucleotides. As the predicted 711-amino-acid protein contains 13 contiguous zinc-finger stuctures of the C2H2 type, it would be expected to function as a DNA-binding multi-finger protein. The 4.3-kb transcript was expressed in all adult human tissues examined by Northern analysis. The gene was assigned to chromosomal band 19q13.4 by fluorescence in situ hybridization.

Transport mechanisms of nucleosides and the derivative, 6-mercaptopurine riboside across rate intestinal brush-border membranes

Na+ -driven nucleoside transport processes across rat intestinal brush-border membrane vesicles were investigated. 6-Mercaptopurine riboside (6-MPR), an analogue of purine-nucleoside such as adenosine and inosine, was recognized by its purine- and pyrimidine-nucleosides transport system, but their nucleobases did not entirely inhibit the 6-MPR transport. The analysis according to the Hill equation of the curve of Na+ activation of 6-MPR uptake was consistent with the notion of a Na+/6-MPR coupling stoichiometry of 1:1. The expressed transport activities of adenosine, uridine, and 6-MPR were Na+ -dependent and saturable, and their affinity constants (Km value) obtained by Eadie-Hofstee analysis were approx. 20, 15 and 100 microM. Moreover, the uptake of radiolabeled adenosine and uridine was trans-stimulated by 6-MPR inside vesicles in the absence of an inwardly directed Na+ gradient. On the other hand, uridine did not exhibit any inhibitory effects on the uptake of adenosine despite the fact that adenosine was a potent inhibitor of uridine uptake by intestinal brush-border membrane vesicles. These differences in the inhibition may be explained by the multiplicity of the nucleoside transport systems.

Expression and functional role of syntaxin 1/HPC-1 in pancreatic beta cells. Syntaxin 1A, but not 1B, plays a negative role in regulatory insulin release pathway

Syntaxin 1/HPC-1 is an integral membrane protein, which is thought to be implicated in the regulation of synaptic neurotransmitter release. We investigated syntaxin 1 expression in pancreatic beta cells and the functional role of syntaxin 1 in the insulin release mechanism. Expression of syntaxin 1A, but not 1B, was detected in mouse isolated islets by the reverse transcriptase-polymerase chain reaction procedure. An immunoprecipitation study of metabolically labeled islets with an anti-rat syntaxin 1/HPC-1 antibody demonstrated syntaxin 1A protein with an apparent molecular mass of approximately 35 kDa. Immunohistochemistry of the mouse pancreas demonstrated that syntaxin 1/HPC-1 was present in the plasma membranes of the islets of Langerhans. In order to determine the functional role of syntaxin 1 in pancreatic beta-cells, rat syntaxin 1A or 1B was overexpressed in mouse beta TC3 cells using the transient transfection procedure. Transfection of beta TC3 cells with either syntaxin 1 resulted in approximately 7-fold increases in their immunodetectable protein levels. Glucose-stimulated insulin release by syntaxin 1A-overexpressing cells was suppressed to about 50% of the level in control cells, whereas insulin release by syntaxin 1B-overexpressing and control cells did not differ. Next, we established stable beta TC3 cell lines that overexpressed syntaxin 1A and used them to evaluate the effect of syntaxin 1A on the regulatory insulin release pathway. Two insulin secretogogues, 4-beta-phorbol 12-myristate 13-acetate or forskolin, increased insulin release by untransfected beta TC3 cells markedly, but their effects were diminished in syntaxin 1A-overexpressing beta TC3 cells. Glucose-unstimulated insulin release and the proinsulin biosynthetic rate were not affected by syntaxin 1A overexpression, indicating a specific role of syntaxin 1A in the regulatory insulin release pathway. Finally, in vitro binding assays showed that syntaxin 1A binds to insulin secretory granules, indicating an inhibitory role of syntaxin 1A in insulin exocytosis via its interaction with vesicular proteins. These results demonstrate that syntaxin 1A is expressed in the islets of Langerhans and functions as a negative regulator in the regulatory insulin release pathway.

Cloning, expression and chromosome mapping of adducin-like 70 (ADDL), a human cDNA highly homologous to human erythrocyte adducin

From a human fetal-brain cDNA library we isolated a novel human cDNA, termed human adducin-like 70 (gene symbol ADDL), whose predicted amino acid sequence showed a high degree of homology to adducins. This cDNA clone (ADDL), which contained an open reading frame of 2,022 nucleotides encoding 674 amino acids, revealed 54%, 53%, and 59% identity in predicted amino acid sequence with alpha and beta components of human adducin and rat adducin 63, respectively. Human adducin-like 70 is likely to play an important role in the skeletal organization of the cell membrane. Northern blot analysis indicated ubiquitous expression of this gene in adult human tissues. We localized the gene to chromosome bands 10q24.2-->q24.3 by fluorescence in situ hybridization (FISH).

Isolation, characterization and chromosomal assignment of the human WNT7A gene

The Wnt genes compose a large gene family encoding a group of secreted signaling molecules that have been implicated in oncogenesis and a number of developmental processes. We have isolated a full-length human cDNA clone that we consider to be a novel member of the Wnt gene family. The gene (WNT7A) encodes a deduced 349-amino-acid peptide with 98% identity in amino acid sequence to murine Wnt7a. Expression of this gene is restricted to certain tissues: placenta, kidney, testis, uterus, fetal lung, and fetal and adult brain. Furthermore, we have isolated a genomic clone of WNT7A and mapped it to chromosome 3p25 by fluorescent in situ hybridization.

Cloning and mapping of a human novel cDNA (NHP2L1) that encodes a protein highly homologous to yeast nuclear protein NHP2

We have isolated a novel human cDNA that encodes a protein highly homologous to NHP2, a nuclear protein of yeast, that is thought to have an essential physiological function for cell viability. The 1,493-bp cDNA sequence includes an open reading frame of 384 bp. This gene (NHP2L1) was expressed in all human tissues examined, and was localized to chromosome hand 12q24.3 by fluorescence in situ hybridization.

Cloning, expression and chromosomal mapping of a novel cyclophilin-related gene (PPIL1) from human fetal brain

We isolated a human cDNA clone encoding a novel protein homologous to cyclophilins, specific cellular targets of cyclosporin A, which are conserved in species ranging from human to prokaryotes. This cDNA, designated hCyPX, contained an open reading frame of 498 nucleotides encoding 166 amino acids. Computer analysis indicated that its predicted amino acid sequence had 41.6%, 40.4%, and 39.2% homology to those of human, bovine, and Drosophila cyclophilins, respectively. Northern blot analysis indicated ubiquitous expression in adult human tissues, but most abundant expression in heart. Fluorescence in situ hybridization to human metaphase chromosomes localized this gene (PPIL1, peptidylprolyl isomerase [cyclophilin]-like 1) to chromosome bands 2p23.3-->p23.1.

Cloning, expression pattern and mapping to 12p 13.2 --> p13.1 of CLAPS3, a gene encoding a novel clathrin-adaptor small chain

From a human fetal-brain cDNA library we isolated a novel gene encoding a peptide homologous to clathrin-adaptor small chains in rat, mouse, and yeast. The cDNA, designated CLAPS3 (clathrin-associated/assembly/adaptor protein, small 3, 22 kDa), contained an open reading frame of 579 nucleotides encoding 193 amino acids. Northern-blot analysis revealed expression of a 1.35-kb transcript in all human tissues examined. This gene was mapped to chromosome bands 12p13.2 --> p13.1 by FISH.

Cloning, expression, and mapping of UBE2I, a novel gene encoding a human homologue of yeast ubiquitin-conjugating enzymes which are critical for regulating the cell cycle

From a human fetal-brain cDNA library we isolated a novel gene sharing significant homology with two yeast genes, UBC9 and hus5, which encode ubiquitin-conjugating enzyme 9 (UBC9). In yeast this protein is critical for normal mitosis, and seems to be closely involved in progression of G2 to M phase of the cell cycle. The human UBC9 (h-UBC9) cDNA, (gene symbol UBE2I), contained an open reading frame of 474 nucleotides encoding 158 amino acids. Its predicted peptide showed respectively 56% and 66% identity (75% and 82% similarity) with the products of UBC9 and hus5. Northern-blot analysis revealed expression of three transcripts, 6.4 kb, 3.3 kb, and 1.35 kb, in all human tissues examined. This gene, UBE2I, was mapped to chromosome band 16p13.3 by FISH.

Cloning, expression, and mapping of TCTEL1, a putative human homologue of murine Tcte1, to 6q

From a human fetal-brain cDNA library we isolated a putative human homologue of the murine Tcte1 gene. The cDNA, designated TCTEL1, contained an open reading frame of 339 nucleotides encoding 113 amino acids. The predicted peptides of TCTEL1 showed 94% and 55% identity (100% and 94% similarity) with those of murine Tcte1 and human RP3. Northern-blot analysis revealed a 0.9-kb transcript in all tissues examined. This gene was mapped by FISH to chromosome bands 6q25.2 --> q25.3, the syntenic region of the murine t-complex locus of chromosome 17.

Isolation and characterization of a human cDNA clone (GCN5L1) homologous to GCN5, a yeast transcription activator

We have isolated a novel human cDNA with a predicted amino acid sequence homologous to GCN5, a protein considered to be a regulator of transcriptional activation in yeast. This cDNA, termed GCN5L1 (GCN5-like 1), consists of 545 nucleotides including an open reading frame of 378 bp that encodes a 126-amino-acid peptide having 23.5% identity to yeast GCN5. Northern-blot analysis revealed transcription of this gene in all human tissues examined. We isolated a genomic clone corresponding to this cDNA from a human cosmid library and mapped it to chromosome 12q13 --> q14 by fluorescent in situ hybridization (FISH).

Isolation and mapping of the human glycoprotein M6 gene (GPM6A) to 4q33-->q34

We have isolated a human cDNA that is highly homologous to the murine gene (Gpm6) encoding a membrane glycoprotein, M6. The human gene (GPM6A) contains an open reading frame of 834 nucleotides encoding a peptide of 278 amino acids. Northern-blot analysis revealed specific expression in human brain. We assigned the GPM6A locus to chromosome bands 4q33-->q34 by radiation hybrid mapping.

Cloning, expression pattern and mapping to Xq of NAP1L3, a gene encoding a peptide homologous to human and yeast nucleosome assembly proteins

From a human fetal brain cDNA library, we isolated a novel gene sharing significant homology with the genes of nucleosome assembly proteins (NAPs). This cDNA clone, designated NAP1L3 (nucleosome assembly protein 1-like 3), contained an open reading frame of 1518 nucleotides encoding 506 amino acids. Its predicted amino acid sequence showed 46% identity and 65% similarity with NAP1L. In its C-terminal half NAP1L3 contained several characteristic motifs strictly conserved with NAP1L and yeast NAP1, but the N-terminal half showed little conservation. Northern-blot analysis revealed strong expression of a 3.0-kb transcript in human adult brain and weak expression in heart. NAP1L3 was closely linked to a marker (DXS990) mapped to chromosome bands Xq21.3-->q22, where genes responsible for several X-linked mental retardation syndromes have been localized.

Specific acceptance of fetal bowel allograft in mice after combined treatment with anti-intercellular adhesion molecule-1 and leukocyte function-associated antigen-1 antibodies

OBJECTIVE

The aim of this study was to see whether tolerance could be induced by simultaneous administration of monoclonal antibodies (MoAbs) to intercellular adhesion molecule-1 (ICAM-1) and leukocyte function-associated antigen-1 (LFA-1) after transplantation of fetal small bowel between fully incompatible mice strains.

METHODS

Fetal small bowel from either BALB/c (H-2d) or C3H/He (H-2k) mice was transplanted into the space between the peritoneum and rectus abdominis of adult C3H/He recipient mice. Syngeneic (n = 6) and two allogeneic transplant groups were made. In one of the allogeneic groups (n = 8), no immunosuppressant was given. In the other allogeneic group (n = 13), both anti-LFA-1 and anti-ICAM-1 MoAbs (50 micrograms each/mouse/day) were given intraperitoneally after transplantation for the first 4 weeks. In the syngeneic and untreated allogeneic groups, all mice were killed 4 weeks after transplantation. In the treated allogeneic group, eight mice were killed 6 weeks after cessation of the MoAb treatment. At the time the mice were killed, the bowel graft as well as the recipient spleen were taken for histologic analysis and cytotoxic T-lymphocyte (CTL) assay, respectively. Each mouse in the remaining treated five mice was transplanted with BALB/c and C57BL/6 (as third-party) full-thickness skin simultaneously 8 weeks after cessation of the MoAb treatment.

RESULTS

All grafts in the syngeneic group survived with normally developing villi, whereas all grafts in the untreated allogeneic group disappeared. In the treated allogeneic group, all allografts developed normal mucosa without any sign of rejection. Splenocytes from the recipient mice in the untreated allogeneic group showed increased CTL induction against donor-type alloantigen (p < 0.005), compared with that in the syngeneic group. Suppressed CTL induction against donor-type alloantigen was observed in the treated allografted recipient (p < 0.001), whereas CTL induction against third-party alloantigen was intact (p = NS). Third-party skin graft was normally rejected within 10 days, whereas donor-type skin graft was accepted in all mice tested.

CONCLUSIONS

Specific tolerance for fetal bowel allografts could be induced by a relatively short-term treatment with anti-ICAM-1 and anti-LFA-1 MoAbs. This mode of immunointervention could perhaps be applied to humans undergoing small-bowel transplantation.

Cloning, expression, and mapping of CKAPI, which encodes a putative cytoskeleton-associated protein containing a CAP-GLY domain

From a human fetal-brain cDNA library we isolated a novel cDNA clone encoding a protein containing a CAP-GLY domain that is highly conserved among several cytoskeleton-associated proteins. The CAP-GLY domain is thought to be essential for their association with microtubules. The cDNA, designated CKAPI (for cytoskeleton-associated protein I, glycine motif) contained an open reading frame of 579 nucleotides encoding 193 amino acids. Northern-blot analysis revealed expression of three transcripts, 1.0, 3.4, and 4.6 kb in size, in all tissues examined. The 1.0-kb transcript was significantly higher in brain and heart than in other tissues. This gene was mapped by FISH to chromosome bands 19q13.11-->q13.12.

Lack of intestinal pacemaker (C-KIT-positive) cells in infantile hypertrophic pyloric stenosis

The pathogenesis of infantile hypertrophic pyloric stenosis (IHPS) is not well understood. Recent studies have shown that the protonocogene c-kit is essential for the development or maintenance of autonomic gut motility, and also show that the c-kit gene protein product (C-KIT) positive cells in the mammalian gut are responsible for intestinal pacemaker activity. This study examines cells in the pyloric muscles of 23 patients (16 with IHPS, 7 controls) for the presence of the C-KIT (C-KIT+), using immunohistochemical techniques with antihuman C-KIT sera. In the controls, many C-KIT immunoreactive (IR+) cells were observed in the muscle layers. The myenteric plexuses were demarcated by a moderate number of C-KIT-IR+ cells. However, in the IHPS patients, C-KIT-IR were either absent or significantly reduced. No C-KIT-IR+ cells were found around the myenteric plexuses. These findings suggest that a lack of c-kit expression (as an indicator of intestinal pacemaker activity) in the hypertrophic pyloric smooth muscles may be an important factor in the pathogenesis of IHPS.

PET study in a patient with spinocerebellar degeneration before and after long-term administration of thyrotropin releasing hormone

We studied the chronic effect of thyrotropin releasing hormone (TRH) in a patient with spinocerebellar degeneration by measuring cerebral metabolic rate for glucose (CMRG1c) using 2-[18F]fluoro-2-deoxy-D-glucose (18FDG) and positron emission tomography (PET). A 56-year-old female, who had suffered from progressive ataxia for 2 years, was treated by intravenous administration of 2 mg TRH for 3 weeks, and CMRG1c of the brain was measured before and after treatment. CMRG1c was markedly decreased in the cerebellum and there was no significant difference before and after the treatment, i.e. mean CMRG1c values were 4.92 and 4.90 mg/100 g/min, and the ratios of the cerebellum versus the frontal cortex were 0.50 and 0.51, respectively. The degree of disequilibrium of her body examined with stabilography became better by the 19th day and further improved by the 26th day after the start of TRH treatment. Based on the present study we conclude that long-term administration of TRH did not improve CMRG1c in the cerebellum, but evidently improved the sway of gravity center by stabilography. We speculate that the chronic effect of TRH was not necessarily due to an improvement of cerebellar function, because TRH receptors are widely distributed throughout the central nervous system.

Isolation and mapping of RAB2L, a human cDNA that encodes a protein homologous to RalGDS

We have isolated a novel human cDNA, designated RAB2L, that encodes a protein homologous to Ral guanine nucleotide dissociation stimulator (RalGDS). The predicted sequence of 122 amino acids revealed 39.5% identity with the C-terminal region of human RalGDS. As the C-terminal region of RalGDS is considered to interact with RAS, the product of this novel gene may also play some role in the ras-mediated signal transduction pathway. Northern analysis revealed that the gene RAB2L is expressed in all human tissues examined. We assigned this gene locus to chromosome band 6p21.3 by fluorescence in situ hybridization.

Effects of the cytokines on the proliferation of and collagen synthesis by human cataract lens epithelial cells

AIMS

To assess the effects of the cytokines, interleukin-1 (IL-1), IL-1 receptor antagonist (IL-1ra), transforming growth factor-beta 2 (TGF-beta 2) and basic fibroblast growth factor (b-FGF), on the mitosis of and collagen synthesis by lens epithelial cells (LECs) of human cataracts.

METHODS

The anterior lens capsule with attached LECs was obtained by capsulotomy during cataract surgery and cultured. The cultures at 2 to 3 weeks before confluency were used for the experiments. To quantify the mitosis and collagen synthesis, the incorporation of 3H-thymidine and 3H-proline, respectively, into the LECs was measured by a scintillation counter at 48 hours and 24 hours, respectively, after addition of the cytokine at various concentrations into the incubation medium.

RESULTS

IL-1 and b-FGF increased the mitosis and collagen synthesis significantly, but IL-1ra significantly decreased the mitosis while leaving the collagen synthesis intact. TGF-beta 2 decreased the mitosis significantly, but increased the collagen synthesis significantly.

CONCLUSION

These cytokines may play an important role in an autocrine or paracrine pathway in the proliferation of residual LECs after cataract surgery. Elucidation of the role of these cytokines may lead to the development of new therapies for the prevention of secondary cataract.

Isolation and mapping of a human gene (DIFF6) homologous to yeast CDC3, CDC10, CDC11, and CDC12, and mouse Diff6

We have isolated a novel human cDNA that encodes a protein homologous to murine H5 and Diff6, and to yeast CDC10, and mapped it to chromosome region 2q37 by fluorescent in situ hybridization. Its transcript has an open reading frame of 1,218 nucleotides encoding 406 amino acids. The deduced peptide sequence contained conserved domains rich in basic residues, GXXGXGKS--DXXG--TKXD, a motif of the GTPase superfamily. Different polyA sites accounted for generation of two transcripts. The major type, 3.5 kb long, was expressed ubiquitously in all human tissues examined, but a 2.0-kb alternative transcript lacking any long AU-rich element in the 3' non-coding region was expressed abundantly only in testis, heart and skeletal muscle.

Molecular cloning of UBE2G, encoding a human skeletal muscle-specific ubiquitin-conjugating enzyme homologous to UBC7 of C. elegans

From a human fetal-brain cDNA library we isolated a novel ubiquitin-conjugating enzyme. The cDNA, designated UBE2G, contained an open reading frame of 510 nucleotides encoding 170 amino acids. The predicted peptide product showed 74% identity at the amino acid level with UBC7 of C. elegans, a high degree of homology with UBC7s of other species, and significant homologies with other subgroups of UBCs. Northern-blot analysis revealed strong expression of 4.4-kb, 2.4-kb, and 1.6-kb transcripts in skeletal muscle. Weak expression was observed in 15 other tissues examined. Radiation-hybrid mapping localized this cDNA to chromosome band lq42.