Development and Crosslinking Properties of Psoralen-Conjugated Triplex-Forming Oligonucleotides as Antigene Tools Targeting Genome DNA

Psoralen-conjugated triplex-forming oligonucleotides (Ps-TFOs) have been utilized for genome editing and anti-gene experiments for over thirty years. However, the research on Ps-TFOs employing artificial nucleotides is still limited, and their photo-crosslinking properties have not been thoroughly investigated in relation to biological activities. In this study, we extensively examined the photo-crosslinking properties of Ps-TFOs to provide fundamental insights for future Ps-TFO design. We developed novel Ps-TFOs containing 2'-O,4'-C-methylene-bridged nucleic acids (Ps-LNA-mixmer) and investigated their photo-crosslinking properties using stable cell lines that express firefly luciferase constitutively to evaluate the anti-gene activities of Ps-LNA-mixmer. As a result, Ps-LNA-mixmer successfully demonstrated suppression activity, and we presented the first-ever correlation between photo-crosslinking properties and their activities. Our findings also indicate that the photo-crosslinking process is insufficient under cell irradiation conditions (365 nm, 2 mW/cm2 , 60 min). Therefore, our results highlight the need to develop new psoralen derivatives that are more reactive under cell irradiation conditions.

Unique Crosslinking Properties of Psoralen-Conjugated Oligonucleotides Developed by Novel Psoralen N-Hydroxysuccinimide Esters

Psoralens and their derivatives, such as trioxsalen, have unique crosslinking features to DNA. However, psoralen monomers do not have sequence-specific crosslinking ability with the target DNA. With the development of psoralen-conjugated oligonucleotides (Ps-Oligos), sequence-specific crosslinking with target DNA has become achievable, thereby expanding the application of psoralen-conjugated molecules in gene transcription inhibition, gene knockout, and targeted recombination by genome editing. In this study, we developed two novel psoralen N-hydroxysuccinimide (NHS) esters that allow the introduction of psoralens into any amino-modified oligonucleotides. Quantitative evaluation of the photo-crosslinking efficiencies of the Ps-Oligos to target single-stranded DNAs revealed that the crosslinking selectivity to 5-mC is the unique feature of trioxsalen. We found that the introduction of an oligonucleotide via a linker at the C-5 position of psoralen can promote favorable crosslinking to target double-stranded DNA. We believe our findings are essential information for the development of Ps-Oligos as novel gene regulation tools.

Selective Photo-Crosslinking Detection of Methylated Cytosine in DNA Duplex Aided by a Cationic Comb-Type Copolymer

In the process of cell development and differentiation, C-5-methylation of cytosine (5-methylcytosine: 5-mC) in genome DNA is an important transcriptional regulator that switches between differentiated and undifferentiated states. Further, abnormal DNA methylations are often present in tumor suppressor genes and are associated with many diseases. Therefore, 5-mC detection technology is an important tool in the most exciting fields of molecular biology and diagnosing diseases such as cancers. In this study, we found a novel photo-crosslinking property of psoralen-conjugated oligonucleotide (Ps-Oligo) to the double-stranded DNA (ds-DNA) containing 5-mC in the presence of a cationic comb-type copolymer, poly(allylamine)-graft-dextran (PAA-g-Dex). Photo-crosslinking efficiency of Ps-Oligo to 5-mC in ds-DNA was markedly enhanced in the presence of PAA-g-Dex, permitting 5-mC-targeted crosslinking. We believe that the combination of PAA-g-Dex and Ps-Oligo will be an effective tool for detecting 5-mC in genomic DNA.

Therapeutic application of sequence-specific binding molecules for novel genome editing tools

Genome editing has been expected to widely increase the available treatment options for various diseases and permit pharmaceutical interventions in previously untreatable conditions. The availability of genome editing tools was dramatically increased by the development of the CRISPR-Cas9 system. However, a number of issues limit the use of the CRISPR-Cas9 system and other gene-editing tools in the clinical treatment of diseases. This review summarized the history and types of genome editing tools and limitations of their use. In addition, the study addressed several next-generation technologies aiming to overcome the limitations of current gene therapy protocols in an effort to accelerate the clinical development of potential treatment options. This review has provided an extensive foundation of the current state of genome editing technology and its clinical development. This review also indicate that the study additionally highlighted the need for multidisciplinary approaches to overcome current bottlenecks in the development of genome editing.

Studies on the structures and antigenic properties of rabies virus glycoprotein analogues produced in yeast cells

We investigated two forms (designated as yGI and yGII) of rabies virus glycoprotein (G) analogues produced in the G cDNA-transfected yeast cells. Molecular weights of yGI and yGII were estimated as 66 and 56 kDa, respectively, according to their relative mobility in SDS-PAGE. Although being produced in large amounts, yGI was present mostly in insoluble forms and hardly extractable with non-ionic detergents. The yGI reacted with polyclonal anti-G antibodies, but did not react with our conformational epitope-specific anti-G monoclonal antibodies (G-MAbs). No protective immunity was induced by yGI in guinea pigs nor in mice. On the other hand, yGII was Triton-soluble, but was only small in amount (at most 1% of total G proteins) and was shown to lack the cytoplasmic domain. The yGII, however, reacted with the G-MAbs and induced protective immunity in guinea pigs as well. When the G-cDNA was expressed in animal cells in culture, a single form (about 66 kDa) of G protein was produced, which displayed similar behaviors as seen in its reactivity with the MAbs and intracellular distribution as seen in the virus-infected cells. These results suggest that most G protein molecules were not processed normally in yeast cells, resulting in abnormal folding and multimer formation, while only a small fraction were occasionally folded normally to have conformational epitopes but were mostly deprived of the C-terminal portion.

Multiple isoforms of neuregulin are expressed in developing rat dorsal root ganglia

Accumulating evidence suggests that neuregulin (NRG) plays special roles in the development of the mammalian nervous system. We have already identified NRG as a survival factor for Schwann cells during development. In this report, we have studied all possible NRG isoforms and expression of NRG in the developing rat dorsal root ganglia (DRG) and compared them with those of brain and spinal cord. Neural NRG isoforms comprise common immunoglobulin and epidermal growth factor domains. Various different transcripts were characterized, which arose by alternative splicing in several regions: N-terminal (exon 1 or 2), spacer (exon 5), juxtamembrane (exon 9 or 10), and cytoplasmic (exon 12, 13, or 14) domains. At least 13 novel isoforms among 16 splice variants were identified. The transmembrane isoforms of NRG are dominant forms in developing rat DRG. The mRNA expression of NRG isoforms in DRG is similar to that in spinal cord, while in brain the expression is much less. The mRNA in DRG was found at similar levels from birth to postnatal day 7 of the premyelinating stage, and it decreased afterward. Our results suggest that several NRGs, including isoforms not reported before, play a role as survival factors for Schwann cells in the premyelinating stage.

Rapid method for detection of point mutations using mismatch binding protein (MutS) and an optical biosensor

This paper describes a new method for detecting DNA point mutations using a mismatch binding protein. The interactions of mismatches and mismatch binding proteins are detected by the optical biosensor technology based on surface plasmon resonance (SPR).

Apoptosis regulates the number of Schwann cells at the premyelinating stage

At the premyelinating stage, the Schwann cells of peripheral nerves are able to recognize the axon, to arrange themselves along it in a nonoverlapping manner, and finally to establish a one-to-one cell-axon relationship. The mechanism that regulates these processes is not known in detail. We found the existence of a significant Schwann cell apoptosis in vivo of rat postnatal sciatic nerve, peaking around postnatal day 3. More than 50% of the neonatal Schwann cells cultured in axon-free medium undergo a rapid apoptosis. The apoptosis can be suppressed by addition of survival factors such as Neu differentiation factors or by increasing the adhesion of Schwann cells to substratum. We suggest that in neonatal nerves in vivo, Schwann cells are highly susceptible to apoptosis, but they are saved from death by contact with axons. The dramatic increase in number of Schwann cells between postnatal day 0 and 3 overcomes the number of axons available for them. Consequently the Schwann cells that fail to contact an axon undergo apoptosis. In conclusion, the number of Schwann cells in the developing nerves is regulated by the apoptosis and clearly depends on the survival signals from axons.

Bifunctional labeling reagent for oligosaccharides to incorporate both chromophore and biotin groups

We have developed a convenient and effective method for biotinylation of oligosaccharides at their reducing ends. A novel biotin hydrazide having a phenyl group produced the biotin adduct of N-acetyllactosamine (LacNAc) by simple incubation at 90 degrees C for 1 h. Although the biotin adduct was obtained as a mixture of several stereoisomers, one of the isomers, cyclic beta-glycoside, became predominant upon letting the reaction mixture stand in a weakly acidic state (pH 3.5). This conversion may be very advantageous for functional analysis of oligosaccharides because natural N-linked oligosaccharides exist in the cyclic beta form. The limit of detection of labeled LacNAc in reversed-phase chromatography was 330 fmol and showed good linearity in the range from 330 fmol to 261 pmol. When this procedure was applied to complex type and high mannose type N-linked oligosaccharides, the labeled oligosaccharides were easily detected and separated by reversed-phase, gel filtration, and anion exchange chromatographies. Furthermore, these labeled oligosaccharides were able to be immobilized onto the solid phase using avidin-biotin technology and were stable enough to allow the binding assay to be performed repeatedly and under the conditions for in situ exoglycosidase digestion. These results suggest that this derivatization technique might be useful for both separation and functional analysis of oligosaccharides.

Expression of CD44H in the cells of neural crest origin in peripheral nervous system

We investigated the expression of the adhesion molecule CD44 in rat peripheral nervous system (PNS) at the protein and mRNA levels. Most migrating neural crest cells strongly expressed CD44, in contrast to the lack of expression in the neural tube. In dorsal root ganglion (DRG) and sciatic nerve, the distribution of CD44, neurofilament (NF) and S100 suggested the localization of CD44 on the membrane of Schwann cell and neurones and in extracellular matrix (ECM). The expression of CD44 was also confirmed on the membrane of cultured neurones and Schwann cells from DRG. mRNA coding for the haematopoietic form of CD44, CD44H, was detected in neural crest cells, DRG neurones and Schwann cells. These results show that CD44 may play some role in migration of neural crest cells and myelination in terms of adhesion between Schwann cells, axons and ECM.

Rhythmic Cl- current and physiological roles of the intestinal c-kit-positive cells

Chronic injection of an anti-c-KIT receptor tyrosine kinase monoclonal antibody (ACK2) results in the disruption of the normal motility patterns of young BALB/c mice intestine. This effect is accompanied by a drastic decrease in the number of intestinal c-kit-expressing (c-kit+) cells when studied immunohistochemically with the fluorescence-labelled antibody. In order to clarify the mechanism underlying the ACK2 action and the physiological roles of intestinal c-kit+ cells, we studied the excitability of intestinal c-kit+ cells in primary culture by use of the nystatin perforated-patch-clamp technique. Under voltage-clamp at -40 mV, the majority of c-kit+ cells tested (59/70) elicited rhythmic current waves with an amplitude and frequency of 263 +/- 24 pA and 2.30 +/- 0.25 cycles/min (mean +/- SEM), respectively. Intracellular perfusion of the c-kit+ cells with ethylenebis (okonitrilo) tetraacetate (EGTA) as well as a nominally Ca(2+)-free external solution or low holding voltage (< -60 mV) prevented the rhythmic current. The reversal potential of the rhythmic current was close to the equilibrium potential for Cl-(ECl). Moreover the rhythmic current was depressed by a Cl- channel blocker, 4-acetoamido-4-isothiocyanat-ostilbene-2,2'-disulphoni c acid (SITS). The smooth muscle cells freshly dissociated from the same intestinal specimen revealed a Ca(2+)-activated K+ current, as has been described in a variety of smooth muscle cells. Cultured smooth muscle cells from the ileum preparation lacked neither the Ca(2+)-activated K+ nor rhythmic Cl- currents. Smooth muscle cells freshly dissociated from the same ileum preparation and those in culture showed no immunoreactivity with the labelled ACK2, which was consistent with our previous in situ study. Results provided direct evidence that the intestinal c-kit+ cells, but not the smooth muscle cells, possess a rhythmic Cl- current oscillation, suggesting their participation in pacemaker activity for the peristaltic gut movement.

Expression of proteolipid protein gene is directly associated with secretion of a factor influencing oligodendrocyte development

Oligodendroglial cell death in the myelin proteolipid protein (PLP) mutants can be partially rescued by the environment factor(s) supplied by the wild-type cells in vivo and in vitro. It is possible that the presence of PLP or DM-20 results in secretion of a factor or factors in the CNS influencing oligodendrocyte development. We previously showed that DM-20 mRNA is produced in G26 mouse oligodendroglioma, B104 rat neuroblastoma, and B16 mouse melanoma but not in NIH3T3 mouse fibroblast cell lines. Culture supernatants from these cell lines were added to primary glial cell cultures from embryonic day 17 mouse brain. After 4 days, the number of oligodendrocytes present in cultures with supernatants from DM-20-producing cells (G26, B104, and B16) was significantly higher than that of control cultures but not with the NIH3T3 supernatant. To investigate more directly whether the PLP gene expression is involved in this process, NIH3T3 cells (nonneural cells) were forced to produce PLP or DM-20. By addition of the supernatants from the PLP/DM-20 transformants, the number of oligodendrocytes in the mixed glial cell cultures increased. This clearly demonstrates that the expression of the PLP gene is sufficient for and directly associated with secretion of a factor, which influences the oligodendrocyte development.

Glial cell degeneration and hypomyelination caused by overexpression of myelin proteolipid protein gene

Myelin proteolipid protein (PLP), the major myelin protein in the CNS, has been thought to function in myelin assembly. Thus, mutations within the gene coding for PLP (Plp) cause hypomyelination, such as the jimpy phenotype in mice and Pelizaeus-Merzbacher disease in humans. However, these mutants often exhibit premature death of oligodendrocytes, which form CNS myelin. To elucidate the functional roles of Plp gene products in the maturation and/or survival of oligodendrocytes, we produced transgenic mice overexpressing the Plp gene by introducing extra wild-type mouse Plp genes. Surprisingly, transgenic mice bearing 4 more Plp genes exhibited dysmyelination in the CNS, whereas those with 2 more Plp genes showed normal myelination at an early age (3 weeks after birth), but later developed demyelination. Overexpression of the Plp gene resulted in arrested maturation of oligodendrocytes, and the severity of arrest was dependent on the extent of overexpression. Overexpression also led to oligodendrocyte cell death, apparently caused by abnormal swelling of the Golgi apparatus. Thus, tight regulation of Plp gene expression is necessary for normal oligodendrocyte differentiation and survival, and its overexpression can be the cause of both dys- and demyelination.

Fate of jimpy-type oligodendrocytes in jimpy heterozygote

In the jimpy mutant mouse, as well as in many other animals with mutations in the myelin proteolipid protein (PLP) gene, oligodendrocytes degenerate before their maturation. To analyze whether this degeneration is caused by the loss of function of PLP gene products related to oligodendrocyte maturation/survival acting extrinsically, expression of the PLP gene was investigated in the jimpy heterozygote, in which one-half of the cells are jimpy type and the other half are wild type due to random X-chromosome inactivation. We first showed that jimpy PLP gene expression is normally regulated at the early stages of development in brains of jimpy hemizygotes and heterozygotes, at least to day 2 after birth. However, the great increase in the level of PLP gene transcripts observed in wild-type mouse brain is suppressed in jimpy mouse brain. This increase was also suppressed in the jimpy heterozygote, and by 2 months after birth, very few jimpy-type PLP gene transcripts were detected in heterozygotes. These results indicate that jimpy-type oligodendrocytes cannot survive or are still in the immature stage in the brain of jimpy heterozygotes. Thus, degeneration of jimpy oligodendrocytes is not caused merely by the lack of trophic factors.

Selective expression of foreign genes in glioma cells: use of the mouse myelin basic protein gene promoter to direct toxic gene expression

We have previously demonstrated that retrovirus-mediated genes were transferred to mouse glioma cells in a meningeal gliomatosis model (Yamada et al.: Japanese Journal of Cancer Research 83:1244-1247, 1992). This retrovirus vector contains the Escherichia coli. beta-galactosidase (beta-gal) gene as a marker for integration of the lacZ gene, which is controlled by the SV40 early promoter. We investigated whether lacZ genes could be specifically controlled in mouse glioma cells by glial-specific promoters, including the 2.5 kb 5' flanking region of the mouse glial fibrillary acidic protein (GFAP) gene, the 1.3 kb 5' flanking region of the myelin basic protein (MBP) gene, and the 1.5 kb 5' flanking region of the myelin proteolipid protein (PLP) gene. Psi-2 packaging cells were transfected with each retrovirus vector (GFAP promoter-, MBP promoter-, and PLP promoter-lacZ) and the infectious virus particles were recovered from the supernatants. Blue staining for beta-gal was detected in various fibroblast, myeloma, and glioma cell lines transduced with the retrovirus BAG vector. On the other hand, blue staining was only detected in glioma cells after transduction with the lacZ gene-bearing retrovirus controlled by glial-specific promoters. The strongest promoter activity was detected after transduction with the retrovirus in which the MBP promoter controlled the lacZ gene. Mouse glioma cells transduced with retrovirus containing the MBP promoter directing the herpes simplex virus type 1 thymidine kinase (HTK) gene were extremely sensitive to ganciclovir, while the parental cells and cells transduced with retrovirus containing the lacZ gene were not sensitive to ganciclovir.(ABSTRACT TRUNCATED AT 250 WORDS)

Possible role of stem cell factor as a serum factor: monoclonal anti-c-kit antibody abrogates interleukin-6-dependent colony growth in serum-containing culture

The monoclonal rat anti-c-kit antibody (ACK2), which abrogates colony growth supported by stem cell factor (SCF), significantly inhibited the interleukin-6 (IL-6)-dependent growth of hematopoietic progenitors derived from spleen cells of normal and 5-fluorouracil (5-FU)-treated mice and from bone marrow cells of normal mice in serum-containing culture. The numbers and types of colonies supported by IL-3, granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF), however, were not influenced by the addition of ACK2 to the cultures of the bone marrow cells from normal mice. In replating experiments with pooled blast cells, ACK2 caused a partial, but significant, inhibition of GM colony growth supported by a combination of IL-6 and fetal bovine serum (FBS), which suggests that FBS is one source of the SCF activity. Conversely, the addition of SCF or FBS with IL-6 to a serum-free culture had significant synergistic effects on the total number of colonies derived from post-5-FU spleen cells and from pooled blast cells. The dose response study showed that the ability of 30% FBS to interact with IL-6 on the colony growth by post-5-FU spleen cells was equivalent to that of approximately 5 ng/mL SCF. These findings suggest that c-kit plays an important role in the growth of hematopoietic progenitors responding to IL-6, and that SCF in the serum affects the development of hematopoietic progenitors in serum-containing cultures.

Novel isoforms of mouse myelin basic protein predominantly expressed in embryonic stage

Myelin basic protein (MBP), a major protein of myelin, is thought to play an important role in myelination, which occurs postnatally in mouse. Here we report that the MBP gene is expressed from the 12th embryonic day in mouse brain and that most of the predominant embryonic isoforms are not those reported previously. These isoforms have a deletion of a sequence encoded by exon 5 from the well-known isoforms. These isoforms show a unique developmental profile, i.e., they peak in the embryonic stage and decrease thereafter. In jimpy, a dysmyelinating mutant, the level of these isoforms remains high even in the older ages. These results suggest that MBPs have heretofore unknown functions unrelated to myelination before myelinogenesis begins. The possible presence of 18 isoforms of MBP mRNA, which are classified into at least three groups with different developmental profiles, is also reported here.

Expression and function of c-Kit in fetal hemopoietic progenitor cells: transition from the early c-Kit-independent to the late c-Kit-dependent wave of hemopoiesis in the murine embryo

The protooncogene c-kit encodes a receptor type tyrosine kinase and is allelic with the W locus of mice. SLF, the c-Kit ligand which is encoded by the Sl locus, has growth promoting activity for hemopoietic stem cells. Previous studies demonstrated that c-Kit is functionally required for the proliferation of hemopoietic progenitor cells at various differentiation stages in adult bone marrow. However, the absence of functional SLF and c-Kit in fetuses with mutant alleles of Sl and W loci produces only minor effects on the myeloid and early erythroid progenitor cells in the fetal liver, although the level of the late erythroid progenitor cells is significantly affected. We used an anti-c-Kit monoclonal antibody to investigate the expression and function of c-Kit in murine fetal hemopoietic progenitor cells. Flow-cytometric analysis showed that hemopoiesis in the yolk sac and fetal liver started from cells that express c-Kit. The c-Kit expression decreased upon maturation into erythrocytes in each organ. By fluorescence activated cell sorting, the c-Kit+ cell population was enriched with the hemopoietic progenitor cells clonable in vitro (CFU-E, BFU-E and GM-CFC). To elucidate whether c-Kit functions in these progenitor cells in vivo, we took advantage of the antagonistic anti-c-Kit monoclonal antibody, ACK2, which can block the function of c-Kit. Administration of ACK2 after 12.5 days of gestation rapidly eliminated BFU-E and GM-CFC as well as CFU-E from the fetal liver. However, the number of these progenitor cells in the yolk sac and fetal liver was less affected when the fetuses were given ACK2 before 12.5 days of gestation. Our results provide evidence that there are two waves of hemopoiesis in murine embryos relative to c-Kit dependency. The c-Kit has an essential role on the growth of hemopoietic progenitor cells in the fetal liver after 12.5 days of gestation, whereas the progenitor cells in the liver and yolk sac of the earlier embryo do not depend on c-Kit and its ligand SLF.

Recombinant LD78 protein, a member of the small cytokine family, enhances osteoclast differentiation in rat bone marrow culture system

Cytokine LD78 is a member of the small inducible protein family involved in cell growth, wound healing and inflammation. However, its exact function is not known. In this study, we demonstrated that recombinant LD78 alpha and its variant LD78 beta proteins stimulate osteoclast-like cell formation in rat bone marrow cultures in the presence of 1 alpha, 25-dihydroxyvitamin D3. This enhancing activity was independent of prostaglandin synthesis. This is the first report which describes the effect of proteins involved in the small inducible protein family on the differentiation of osteoclasts.

Suppressive effect of LD78 on the proliferation of human hemopoietic progenitors

LD78 is a cDNA newly isolated from human stimulated tonsillar lymphocytes. The expression of LD78 is related to inflammatory responses and its structure has a homology with macrophage inflammatory protein 1-alpha, which is known to have an inhibitory effect on murine CFU-S. Using a colony assay technique, we examined the effects of LD78 on human hemopoietic progenitors. The addition of doses of 100 ng/ml or more of LD78 suppressed the colony formation of KMT-2, a factor-dependent myelomonocytic cell line established from cord blood cells; this suppressive activity was neutralized by the addition of antibody against LD78. The same doses of LD78 suppressed the formation of neutrophil, macrophage, and megakaryocytic colonies which were supported by human interleukin-3 and erythropoietin; however, LD78 did not affect colony formation by either non-phagocytic mononuclear cells or sorted CD34+ cells. The conditioned medium of KMT-2 cells or peripheral blood mononuclear cells cultured with LD78 suppressed colony formation by CD34+ cells. From these findings, it is suggested that LD78 affects phagocytic cells and induces factors that are inhibitory for hemopoiesis. We consider LD78 to be a new cytokine that plays an inhibitory role in hemopoiesis.

Formation of GABOB from 2-hydroxyputrescine and its anticonvulsant effect

To investigate the formation of gamma-amino-beta-hydroxybutyric acid from 2-hydroxyputrescine in mammalian organs, the radioactive diamine was synthesized and was injected into rats intraperitoneally or intraventricularly. After intraperitoneal injection, the radioactive amino acid was detected in various organs, but formation of the stereoisomer of the amino acid (gamma-amino-alpha-hydroxybutyric acid) was not demonstrated. Intraventricular injection of the radioactive diamine also resulted in the formation of gamma-amino-beta-hydroxybutyric acid in the rat brain. In vivo experiments using monoamine oxidase or diamine oxidase inhibitors suggested the participation of both enzymes in the formation of the amino acid from the diamine in rat organs other than the brain, where diamine oxidase appeared to play the major role. To investigate the anticonvulsant effect of 2-hydroxyputrescine, the threshold of pentylenetetrazol-induced generalized convulsions was measured in rats after the intraventricular injection of 2-hydroxyputrescine. Both R(-)- and S(+)-2-hydroxyputrescine had an anticonvulsant effect, with a greater elevation of the threshold being observed after injection of the R(-) form. Time course experiments suggested that this anticonvulsant effect depended on the formation of gamma-amino-beta-hydroxybutyric acid from 2-hydroxyputrescine in the rat brain. The anticonvulsant action of gamma-amino-beta-hydroxybutyric acid was also examined, and the stimulation of Cl- influx plus the inhibition of GABA uptake into brain membrane vesicles were indicated to be involved.

Carbamazepine-induced eruption histologically mimicking mycosis fungoides

Carbamazepine is an important drug used in the management of seizures, trigeminal neuralgia, and chronic pain syndromes. It has been associated with a variety of adverse skin reactions including urticaria, lichenoid eruptions, erythroderma, erythema multiforme, Stevens-Johnson syndrome, and toxic epidermal necrolysis. A 39-year-old white male had been started on carbamazepine for intractable pain which resulted from a right foot crush injury. Approximately 3 months after the start of therapy, the patient had developed a generalized skin eruption following an entire day of sun exposure. Skin biopsies revealed an atypical lymphoid infiltrate in the dermis with collections of the atypical lymphocytes within spongiotic vesicles in the epidermis, suggestive of mycosis fungoides. The patient was treated with systemic prednisone. Subsequent biopsies failed to reveal atypical lymphocytes. Previous reports have described spongiotic eruptions with foci of atypical lymphocytes in contact dermatitis and in patients treated with phenytoin. To the best of our knowledge, this is the first reported case of a carbamazepine-induced eruption simulating mycosis fungoides histologically.

The conformation of mature human alpha-amylase conditions its secretion from yeast

The yeast Saccharomyces cerevisiae expresses the cloned cDNA (Amy) encoding human salivary alpha-amylase (Amy) under control of the yeast PHO5 promoter, and secretes the active enzyme into the culture medium. Two approaches were utilized to define the moiety of Amy, which is required for proper secretion and glycosylation. In one approach, chimeras were constructed with a variety of secretion signal sequences (yeast mating factor precursor sequence, yeast acid phosphatase signal sequence and human gastrin signal sequence) fused to the secretion signal-deleted Amy cDNA. The other approach involved analysis of a set of deletion series and a set of point mutations in the Amy-encoding region. The results showed that heterologous signal sequences were sufficient for proper secretion in yeast, irrespective of the insertion of some extra amino acids. In most cases, enzymes with deletions and Cys-465 substitution were not secreted, even though they had complete secretion signal sequences. Instead, they accumulated in the cell in a glycosylated form. Thus, proper secretion seems to require an appropriate conformation in the polypeptide moiety to be secreted.

Formation of gamma-amino-beta-hydroxybutyric acid from 2-hydroxyputrescine in rat brain

gamma-Amino-beta-[3H]hydroxybutyric acid ([3H]-GABOB) was formed in rat brain from 2-[3H]-hydroxyputrescine that had been chemically synthesized from 2-oxoputrescine and [3H]sodium borohydride. After the injection of 2-[3H]hydroxyputrescine into the lateral ventricle of a rat brain, the rat was killed and then the brain was removed. [3H]GABOB in the brain was identified by a combination of ion-exchange chromatography, high-voltage paper electrophoresis, and recrystallization of the radioactive compound with authentic GABOB.

Expression of hepatitis B virus middle and large surface antigen genes in Saccharomyces cerevisiae

The hepatitis B virus genome carries the surface antigen (SAg) gene and an open reading frame that encodes two SAg-related polypeptides: SAg with a 55-amino-acid N-terminal extension polypeptide and SAg with a 174-amino-acid N-terminal extension polypeptide. These are termed middle S and large S, respectively. These polypeptides or their glycosylated derivatives have been detected in Dane particles, but their chemical and biological properties have remained largely unknown because of their limited availability. We attempted to produce these proteins in Saccharomyces cerevisiae by placing the coding regions under the control of the promoter of the yeast glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene. Yeast cells carrying middle S and large S coding sequences produced 33,000- and 42,000-dalton products, respectively, each of which reacted with anti-S antibody and bound to polymerized human serum albumin, in accordance with the known properties of pre-S proteins from particles in human sera (K. H. Heermann, U. Goldmann, W. Schwartz, T. Seyffarth, H. Baumgarten, and W. H. Gerlich, J. Virol. 52:396-402, 1984; A. Machida, S. Kishimoto, H. Ohnuma, K. Baba, Y. Ito, H. Miyamoto, G. Funatsu, K. Oda, S. Usuda, S. Togami, T. Nakamura, Y. Miyakawa, and M. Mayumi, Gastroenterology 86:910-918, 1984). The middle S polypeptide is glycosylated and can be assembled into particles whose size and density are similar to those of SAg. However, this polypeptide was highly susceptible to proteolytic degradation into 29,000- and 26,000-dalton polypeptides, of which only the former retained the binding activity to polymerized albumin. The large S polypeptides are nonglycosylated, relatively stable, and do not seem to assemble into particles by themselves.

Determination of putrescine in brain tissue using gas chromatography-mass spectrometry

We used gas chromatography-mass spectrometry to assay putrescine in minute regions of single rat brains. Acid extraction, partial purification on Amberlite CG 120, and derivatization with pentafluoropropionic anhydride preceded the gas chromatography-mass spectrometry. A moving-needle solventless system and a direct inlet system were also used to increase sensitivity. Putrescine was measured accurately at the picomole level; the mean concentration of this polyamine in five regions of rat brain found by this method was 2.7-3.8 times higher than reported by other researchers.

Hypothermia caused by antipsychotic drugs in a schizophrenic patient

In a schizophrenic patient, hypothermia was caused by combined treatment with zotepine, biperiden, and fluphenazine, although combined treatment with zotepine and biperiden had caused no side effects. Other side effects closely resembled those in neuroleptic malignant syndrome.

The effect of L-erythro-dihydroxyphenylserine injected into the lateral ventricle and the hypothalamus on the locomotor activity

The effect of dihydroxyphenylserine (DOPS) on locomotor activity was studied using the Animex activity meter. One microgram of L-erythro-DOPS, a precursor of d-noradrenaline, was injected into the lateral ventricle once a day for one week or into the anterior hypothalamic area (AHA) once. After the intraventricular injection, the total locomotor activity (from 8:00 p.m. to 8:00 a.m.) of the rats injected with DOPS was significantly less than that of the rats injected with an artificial cerebrospinal fluid (5-ion). Analysis of the locomotor activity in consecutive 2-hr periods showed that the activity of the DOPS group during the time intervals of 10 p.m.-12 a.m., 12 a.m.-2 a.m. and 2 a.m.-4 a.m. was significantly less than that of the control group. After injection of DOPS or 5-ion into AHA, the total activity of the DOPS group was significantly less than that of the control. Analysis of the activity of the DOPS group for each 2-hr period between 10 p.m.-4 a.m. was also significantly less than that of the control. On the basis of these findings, the effect of DOPS in the brain noradrenergic system are discussed.

Saccharomyces cerevisiae PHO5 promoter region: location and function of the upstream activation site

Saccharomyces cerevisiae repressible acid phosphatase (PHO5) is induced when inorganic phosphate in the culture medium is depleted. To study the mechanism of this regulation, we constructed various deletions in the 5'-flanking region of the PHO5 gene. Two elements were revealed by this analysis: an upstream activation site (UAS) and a downstream element, both playing parts in the expression of this gene. The UAS is located between -384 and -292 upstream of the initiation codon and activates expression of the gene when inorganic phosphate is depleted. It consists of two homologous regions (UAS I and UAS II) that contain CTGCACAAATG and an adenine-plus-thymine-rich sequence, either one of which suffices for the effect. The downstream element includes a putative TATA box at -100 from the ATG codon and is necessary for efficient transcription and expression of the normal-sized PHO5 transcript. The distance between the UAS and the downstream element can be altered without causing loss of expression efficiency, and the action of the UAS is not affected by its orientation. These results are consistent with a model wherein UAS acts as a site of activation for transcription by interaction with a protein factor(s) that becomes active when inorganic phosphate is depleted from the culture medium.

Spontaneous release of gamma-aminobutyric acid formed from putrescine and its enhanced Ca2+-dependent release by high K+ stimulation in the brains of freely moving rats

The spontaneous release of [3H] gamma-aminobutyric acid ([3H]GABA) in various areas of rat brain injected with [3H]putrescine was examined using a push-pull perfusion technique. The release in a 25-min perfusate was highest in the caudate-putamen. The effect of high K+ stimulation on the release of [3H]GABA formed from [3H]putrescine was examined in the caudate-putamen. The release was enhanced by high K+ solution in a Ca2+-dependent manner.

Ultrastructural appearances of subcultured aortic smooth muscle cells migrating into Millipore filters

The ultrastructures of vascular smooth muscle cells migrating in Millipore filters were examined using a modified Boyden chamber. The cells (seventh and eighth subculture) were obtained from explants of rat aorta. Very small numbers of bipolar-shaped cells migrated deeply into the filter toward a platelet suspension added to the lower compartment. The migrating cells were richer in intermediate filaments and microtubules than the cells on the filter. The cytoskeleton was oriented along the elongated cell body, and the cortical microfilamentous mat was disorganized along the entire cell periphery. These data are discussed.

Enhancement of endogenous production of 12-L-hydroxy-5,8,10,14-eicosatetraenoic acid in aortic smooth muscle cells by platelet-derived growth factor

Platelet-derived growth factor (PDGF) has a chemotactic effect on smooth muscle cells, which is inhibited by lipoxygenase inhibitor caffeic acid. In order to study the role of endogenous lipoxygenase products of arachidonic acid on the chemotactic action of PDGF, effects of PDGF on the lipoxygenase pathway in smooth muscle cells were examined. Lipoxygenase products were analyzed by high-performance liquid chromatography. 15-, 5- and 12-lipoxygenase activities, in order of magnitude, were found in smooth muscle cell homogenate. However, when the lipoxygenase products were analyzed using intact cells prelabelled with [14C]arachidonic acid, only 12-L-hydroxy-5,8,10,14-eicosatetraenoic acid (HETE) was found to be produced endogenously. In addition, 12-HETE was not released into the medium. Treatment of the cells with PDGF increased the endogenous production of 12-HETE. The amounts of intracellular 12-HETE in PDGF-treated cells were 126, 132 and 146% at 1, 3, and 10 hr's after the initiation of PDGF treatment, respectively, when control value at each time point was considered as 100%. Caffeic acid (10(-4) M) completely inhibited the PDGF effect on 12-HETE production. However, PDGF treatment did not significantly alter the 12-lipoxygenase activity. These results suggest that the stimulatory effect of PDGF on 12-HETE production was not mediated by the activation of 12-lipoxygenase activity. Since 12-HETE itself is a potent chemoattractant for smooth muscle cells, the present dat strongly suggest that 12-HETE could be an important intracellular mediator of the chemotactic action of PDGF on aortic smooth muscle cells.

Long-term treatment of postmenopausal osteoporosis with active vitamin D3, 1-alpha-hydroxycholecalciferol (1 alpha-OHD3) and 1, 24 Dihydroxycholecalciferol (1, 24(OH)2D3)

The effects of active vitamin D3 analogues on radial mineral content (RMC) in postmenopausal osteoporosis were examined. Seventy eight subjects with postmenopausal osteoporosis were divided into 5 groups; Group 1 (n = 23) as the control group and Group 2 (n = 27), Group 3 (n = 8), Group 4 (n = 9) and Group 5 (n = 11) which were given 1 microgram of 1, 24(R) (OH)2D3 per day, 1 microgram of 1, 24(S)(OH)2D3 per day, 0.5 and 1 microgram of 1 alpha-OHD3 per day for 6 to 24 months, respectively. After 3-months administration of these drugs, RMC values were significantly increased in Groups 2 (102.8 +/- 1.8%), 4 (103.9 +/- 3.3%) and 5 (114.2 +/- 3.6%), when compared with the controls (97.9 +/- 2.4%). RMC in Group 3 (97.9 +/- 2.4%) was not significantly different from the control value. The administration of 1 alpha-OHD3 caused in increase in RMC in a dose-related manner. A rapid decrease in RMC was observed after withdrawal of the treatment in Groups 2, 4, and 5. A subsequent increase in RMC was observed after re-administration of 1 alpha-OHD3 and 1, 24(R)(OH)2D3. Serum Ca levels were increased in the group treated with 1, 24(R)(OH)2D3 and were decreased after the discontinuation of 1 alpha-OHD3 administration. Serum A1-P activity was decreased by treatment with 1 alpha-OHD3 (1 microgram per day) and a subsequent increase was observed in both groups treated with 1, 24(R)(OH)2D3 and 1 alpha-OHD3. Serum PTH levels were decreased by the administration of 1, 24(R)(OH)2D3 and 1 alpha-OHD3. In the group treated with 1 microgram of 1 alpha-OHD3 per day, hypercalcemia (2 out of 11 cases and these patients took calcium tablets) and an increase in BUN (1 out of 2 hypercalcemic patients) were observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Stimulatory effect of insulin on aortic smooth muscle cell migration induced by 12-L-hydroxy-5,8,10,14-eicosatetraenoic acid and its modulation by elevated extracellular glucose levels

In investigations on the role of insulin on migration of rat aortic smooth muscle cells, migration of the cells was measured by a modified Boyden chamber technique with 12-L-hydroxy-5,8,10,14-eicosatetraenoic acid (12-HETE) as a chemoattractant. Insulin itself was not a chemoattractant for these cells, and insulin added just before the migration assay did not affect cell migration in the presence or absence of 12-HETE. Cells pretreated with insulin in culture dishes for a long period, however, showed a significant increase in migration induced by 12-HET, and the increase depended on the insulin concentration: concentrations of insulin of greater than 50 microIU/ml caused about twofold increase in cell migration. On the other hand, long-term incubation with various concentrations of insulin (0.15-1000 microIU/ml) did not affect nonspecific cell migration in the absence of 12-HETE. The stimulatory effect of insulin on cell migration gradually increased with the duration of insulin treatment, reaching a plateau after 4 days. Thus, insulin stimulated 12-HETE-induced smooth muscle cell migration in a time- and dose-dependent manner. When the extracellular D-glucose concentration in the Boyden chamber was increased from 100 to 300 mg/dl, the stimulatory effect of insulin on 12-HETE-induced cell migration was augmented. This modulation by D-glucose was not due to an increase in the osmotic pressure of the medium, since addition of mannitol to increase the osmotic pressure did not enhance the effect of insulin on cell migration.(ABSTRACT TRUNCATED AT 250 WORDS)

Age-related increase in the migration of aortic smooth muscle cells induced by 12-L-hydroxy-5,8,10,14-eicosatetranoic acid

Studies were made on how age influenced the migration of aortic smooth muscle cells. For this, aortic cells from rats of various ages were established in culture in vitro and migration of the cells was measured by the filter membrane technique in modified Boyden chambers. 12-L-Hydroxy-5,8,10,14-eicosatetraenoic acid (12-HETE), which is mainly produced by platelets and leukocytes and is a strong chemoattractant for rat aortic smooth muscle cells, was used at a concentration of 6 X 10(-15) g/ml in this work. Proliferation of smooth muscle cells decreased significantly with age, but the plating efficiency and cell size did not. In contrast, cell migration induced by 12-HETE showed an age-related increase: The 12-HETE-induced cell migration activities of cells from 6- and 25-month-old rates were 226.7 +/- 35.4 and 223.2 +/- 37.9 cells/10 high-power fields (HPF), respectively, which were significantly higher than that of 121.4 +/- 20.1 cells/10 HPF for cells from 2-month-old rats (P less than 0.05). There was no age-related change in the dose-response curve to 12-HETE for migration of smooth muscle cells. The observed changes are closely associated with the processes of development and maturation of rat aorta.

Antitumor activity in the culture supernatant fluid of Fusobacterium nucleatum strain KO-31

Antitumor activity of Fusobacterium nucleatum strain KO-31, which had been isolated from the oral cavity, was investigated in Ehrlich carcinoma-bearing mice. The strain KO-31 was cultured in TF medium for 48 hr. One-half ml of the culture supernatant fluid was injected intraperitoneally during a 7-day period to mice with Ehrlich ascites carcinoma. The survival time of the treated mice prolonged remarkably. A significant reduction in size of the solid Ehrlich tumor was also achieved with the supernatant. Antitumor activity was not observed in the cell extract.

Aortic smooth muscle cell migration caused by platelet-derived growth factor is mediated by lipoxygenase product(s) of arachidonic acid

The relation between platelet-derived growth factor (PDGF)-induced smooth muscle cell migration, measured in Boyden chambers, and cellular arachidonic acid cascade was studied by using rat aortic smooth muscle cells. Partially purified PDGF stimulated cell migration significantly at a concentration of 1.33-133.0 micrograms/ml. Treatment of the cells with 10(-4)M of 5,8,11,14-eicosatetraynoic acid, an inhibitor of lipoxygenase and cyclooxygenase, and 10(-4)M of caffeic acid, a specific inhibitor of lipoxygenase, caused a significant suppression of PDGF-induced cell migration. Treatment with indomethacin, an inhibitor of cyclooxygenase, did not affect cell migration. These data indicate the involvement of a lipoxygenase product(s) of arachidonic acid in PDGF-associated smooth muscle cell migration.

Calcium dependency of aortic smooth muscle cell migration induced by 12-L-hydroxy-5,8,10,14-eicosatetraenoic acid. Effects of A23187, nicardipine and trifluoperazine

We have previously reported that 12-L-hydroxy-5,8,10,14-eicosatetraenoic acid (12-HETE), a 12-lipoxygenase product of arachidonic acid in platelets, is a potent chemoattractant for rat aortic smooth muscle cells. In the present study, the mechanism involved in 12-HETE-associated smooth muscle cell migration was investigated in relation to calcium mobilization in the cells. Migration of smooth muscle cells was measured by a filter membrane technique in modified Boyden chambers. Smooth muscle cell migration induced by 12-HETE increased with the increase of extracellular Ca2+ concentration and became maximal at the physiological Ca2+ concentration of 1.25 mM. The calcium ionophore A23187, at concentrations of 0.2 and 2.0 microM, significantly stimulated cell migration. Nicardipine, a potent calcium-entry blocker, significantly inhibited 12-HETE-associated smooth muscle cell migration at concentrations from 10(-9) to 10(-5) M. Concentrations of trifluoperazine from 10(-9) to 10(-5) M and W-7 at 10(-5) M, which are specific inhibitors of calmodulin, also significantly inhibited cell migration induced by 12-HETE. Cytochalasin B at 1.0 and 10 microM, and colchicine at 0.1 and 1.0 microM concentrations drastically inhibited cell migration, indicating that actin-containing microfilaments and microtubules are involved in smooth muscle cell migration. These findings indicated that the stimulation of smooth muscle cell migration by 12-HETE is a highly calcium-dependent process and suggest that 12-HETE might act at the initial stage of smooth muscle cell migration through enhancing calcium influx through plasma membrane and thus stimulating cell migration.

Induction of fatty acid cyclooxygenase in rat aortic smooth muscle cells by estradiol

We have previously reported that estradiol stimulates prostacyclin biosynthesis in cultured rat aortic smooth muscle cells by increasing fatty acid cyclooxygenase activity, and induction of new protein biosynthesis is involved since the effect of estradiol is blocked by cycloheximide treatment. In order to see whether estradiol stimulates de novo biosynthesis of fatty acid cyclooxygenase in cells, a specific radioimmunoassay of fatty acid cyclooxygenase was used to measure the enzyme. Estradiol significantly increased immunoreactive fatty acid cyclooxygenase in cells. Consequently, increase in cyclooxygenase activity results in the production of more prostaglandin endoperoxides for final increased synthesis of prostacyclin in these cells.

Comparative effect of lipoxygenase products of arachidonic acid on rat aortic smooth muscle cell migration

We investigated the effects of mono-hydroxyeicosatetraenoic acids (HETEs) and N-formyl-methionyl-leucyl-phenylalanine (F-Met-Leu-Phe) on rat aortic smooth muscle cell migration in modified Boyden chambers. 12-HETE showed the most potent stimulatory effect on smooth muscle cell migration among the mono-HETEs tested. The optimal concentrations for cell migration were 3 X 10(-15) and 3 X 10(-13) g/ml for 12-HETE and 10(-8) g/ml for 15-HETE, 5-HETE and F-Met-Leu-Phe were inactive with these cells. As 12-HETE is biosynthesized from arachidonic acid by the 12-lipoxygenase pathway in platelets and macrophages, and 15-HETE by the 15-lipoxygenase pathway in granulocytes, the present results indicate an important role for such cells in the early phase of atherosclerosis.

Stimulation of 12-lipoxygenase activity in rat platelets by 17 beta-estradiol

The effects of estradiol on the endogenous fatty acid (specifically, arachidonic acid) composition of cellular phospholipid fractions and the 12-lipoxygenase activity in rat platelets in vivo were studied. Estradiol had no significant effect on the endogenous fatty acid composition of cellular phospholipid fractions. However, estradiol significantly increased 12-lipoxygenase activity in platelets in a dose-dependent manner. The stimulatory effect of estradiol on platelet lipoxygenase was blocked by the anti-estrogen nafoxidine hydrochloride which was injected simultaneously together with estradiol in vivo, suggesting that the effect in target cells was due directly to estradiol.

Platelets stimulate aortic smooth muscle cell migration in vitro. Involvement of 12-L-hydroxy-5,8,10,14-eicosatetraenoic acid

The migration of rat aortic smooth muscle cells was measured in modified Boyden chambers. Smooth muscle cells were motile in vitro and their migration was stimulated (time- and dose-dependently) by a platelet-derived factor. Treatment of platelets with indomethacin resulted in a significant increase in smooth muscle cell migration, whereas treatment with 5,8,10,14-eicosatetraenoic acid inhibited it. Purified 12-L-hydroxy-5,8,10,14-eicosatetraenoic acid at a very low concentration (6 x 10(-15)-6 x 10(-13) g/ml) significantly stimulated smooth muscle cell migration. The locomotion induced by 12-L-hydroxy-5,8,10,14-eicosatetraenoic acid was chemokinetic. These findings point to the physiological importance of a platelet 12-lipoxygenase product of arachidonic acid in the early phase of atherosclerosis.

Effects of reduced glutathione on the 12-lipoxygenase pathways in rat platelets

Arachidonic acid is converted into several more polar products in addition to 12-l-hydroperoxyeicosa-5,8,10,14-tetraenoic acid (12-HPETE) and 12-l-hydroxyeicosa-5,8,10,14-tetraenoic acid (12-HETE) by the cytosol fractions of rat platelets. The more polar products are formed via the lipoxygenase pathways in the same way as are 12-HPETE and 12-HETE, since their formation is not inhibited by indomethacin but by eicosa-5,8,11,14-tetraynoic acid (ETYA). The presence of 0.5-1.5mm-reduced glutathione (GSH) in the reaction mixture prevents the formation of the more polar products and produces 12-HETE as the only metabolite from arachidonic acid by the 12-lipoxygenase pathway. l-Cysteine has the same effect as GSH. However, oxidized glutathione (GSSG) and l-cystine are not able to prevent the formation of the more polar products. The results indicate that 12-HPETE peroxidase in the 12-lipoxygenase pathway is a GSH-dependent peroxidase and the more polar products might be formed from the non-enzymic breakdown of the primary 12-lipoxygenase product of 12-HPETE, owing to insufficient capability of the subsequent peroxidase system to completely reduce 12-HPETE to 12-HETE. Thus the presence of GSH in the reaction mixture offers a convenient and precise cell-free assay system for 12-lipoxygenase in rat platelets. Routine assays of 12-lipoxygenase are carried out in the presence of 1mm-GSH in the reaction mixture. The synthesis of 12-HETE by 12-lipoxygenase is linear during the first 4 min of incubation at 37 degrees C, and has a pH optimum of 7.7. The 12-lipoxygenase reaches half-maximal activity at an arachidonate concentration of 20mum. Fractionation of cell homogenates indicates that the cytosol fraction possesses almost all the 12-lipoxygenase activity, whereas the microsomal fraction exhibits little enzyme activity.