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A Wanaka

Publications and source records attributed to A Wanaka.

At least 37 records · Page 2Linked to original sources
PubMed1997

Expression of zinc transporter gene, ZnT-1, is induced after transient forebrain ischemia in the gerbil.

To elucidate the molecular mechanisms underlying neuronal death after transient forebrain ischemia, we cloned genes expressed after transient forebrain ischemia in the Mongolian gerbil by a differential display method. A gerbil homolog of rat zinc transporter, ZnT-1, which transports intracellular Zn2+ out of cells, was isolated. Its expression became detectable exclusively in pyramidal neurons of the CA1 region 12 hr after ischemia and reached a maximum from day 1 to day 2 as shown by in situ hybridization. By day 7, expression had disappeared entirely from the cells in the CA1 region, because the neurons had died. No other brain regions exhibited such a significant level of ZnT-1 mRNA expression during this period. Zn2+ was shown to accumulate in CA1 pyramidal neurons expressing ZnT-1 mRNA after the ischemia by using zinquin, a zinc-specific fluorescent dye. When primary hippocampal neurons were exposed to a high dose of Zn2+, ZnT-1 mRNA accumulated. These results suggest that the induction of ZnT-1 mRNA observed in CA1 neurons was caused by an increase in the intracellular Zn2+ concentration. It was reported recently that Zn2+ chelator blocked neuronal death after ischemia and that the influx of Zn2+ might be a key mechanism underlying neuronal death. The induction of ZnT-1 mRNA in CA1 pyramidal neurons fated to die after transient ischemia is of interest to the study of postischemic events and the molecular mechanisms underlying delayed neuronal death.

Amino Acid Sequence↗
PubMed1997

Molecular cloning of a novel polypeptide, DP5, induced during programmed neuronal death.

To study the molecular mechanisms underlying neuronal programmed cell death (PCD), we performed differential display screening for genes, the expression of which was induced during PCD in the sympathetic neuron culture model deprived of NGF. We cloned a gene encoding a novel polypeptide (DP5) which consisted of 92 amino acids. DP5 polypeptide had no homology with any other known protein and contained no motif that would indicate its putative biochemical functions. DP5 mRNA levels peaked at 15 h after nerve growth factor withdrawal, concurrent with the time at which neurons were committed to die. The induction of DP5 gene expression was blocked when cell death was rescued by treatment with cycloheximide, KCl, or the cyclic AMP analogue CPTcAMP. Overexpression of the full-length DP5 in cultured sympathetic neurons was in itself sufficient to induce apoptosis. These results suggest that DP5 plays a role in programmed neuronal death.

Amino Acid Sequence↗
PubMed1997

Cloning of a putative vesicle transport-related protein, RA410, from cultured rat astrocytes and its expression in ischemic rat brain.

To elucidate the role of astrocytes in the stress response of the central nervous system to ischemia, early gene expression was evaluated in cultured rat astrocytes subjected to hypoxia/reoxygenation. Using differential display, a novel putative vesicle transport-related factor (RA410) was cloned from reoxygenated astrocytes. Analysis of the deduced amino acid sequence showed RA410 to be composed of domains common to vesicle transport-related proteins of the Sec1/Unc18 family, including Sly1p and Sec1p (yeast), Rop (Drosophila), Unc18 (Caenorhabditis elegans), and Munc18 (mammalian), suggesting its possible role in vesicular transport. Northern analysis of normal rat tissues showed the highest expression of RA410 transcripts in testis. When astrocyte cultures were subjected to a period of hypoxia followed by reoxygenation, induction of RA410 mRNA was observed within 15 min of reoxygenation, reaching a maximum by 60 min. At the start of reoxygenation, the addition of diphenyl iodonium, an NADPH oxidase inhibitor, blocked in parallel astrocyte generation of reactive oxygen intermediates and expression of RA410 message. In contrast, cycloheximide did not affect RA410 mRNA levels, indicating that RA410 is an immediate-early gene in the setting of reoxygenation. Using polyclonal antibody raised against an RA410-derived synthetic peptide, Western blotting of lysates from reoxygenated astrocytes displayed an immunoreactive band of approximately 70 kDa, the expression of which followed induction of the mRNA. Fractionation of astrocyte lysates on sucrose gradients showed RA410 antigen to be predominantly in the plasma membrane. Immunoelectron microscopic analysis demonstrated RA410 in large vesicles associated with the Golgi, but not in the Golgi apparatus itself, consistent with its participation in post-Golgi transport. Consistent with these in vitro data, RA410 expression was observed in rat brain astrocytes following transient occlusion of the middle cerebral artery. These data provide insight into a new protein (RA410) that participates in the ischemia-related stress response in astrocytes.

Amino Acid Sequence↗
PubMed1997

Apoptosis induced in the spinal cord and dorsal root ganglion by infection of herpes simplex virus type 2 in the mouse.

After inoculation of a highly neuro-invasive strain of herpes simplex virus (HSV) type 2 (186) into the mouse hind-paw planter skin, many virus-positive neurons and glial cells were detected in the dorsal root ganglia (DRGs) and lumbar spinal cord by immunohistochemistry for HSV-2 antigen. A number of apoptotic cells were also observed in the spinal cord and DRGs by the terminal dUTP nick-end-labeling (TUNEL) method. Double labeling with the immunohistochemistry for HSV-2 and the TUNEL method revealed further that some glial and neuronal cells in the spinal cord, either infected or non-infected by HSV-2, showed apoptotic signs. In DRGs, however, apoptosis was detected in no neuronal cells, although some of HSV-2 -infected glial cells were apoptotic.

Animals↗
PubMed1997

Expression of tPA mRNA in the facial nucleus following facial nerve transection in the rat.

Plasminogen activators (PAs) have been suggested to play a role in neuronal migration and glial cell proliferation in the developing CNS. Less is known, however, about the role of PAs in the mature nervous system. To elucidate the role of tissue type plasminogen activator (tPA) in the nervous system we used in situ hybridization to study the expression of tPA mRNA within the rat facial nucleus after facial nerve transection. We also studied the effect of MK-801 on tPA mRNA expression in order to investigate whether the previously reported N-methyl-D-aspartate (NMDA) receptor activation is involved in this model. tPA mRNA was expressed in the ipsilateral facial motoneurones from 6 h after injury. This expression continued for at least 2 weeks after facial nerve transection. Administration of MK-801 before axonal injury did not affect the expression of tPA mRNA in the facial nucleus. These data suggest that tPA might be involved in the regenerative process without NMDA receptor activation in mature facial neurones.

Animals↗
PubMed1997

Molecular cloning of mouse Doc2alpha and distribution of its mRNA in adult mouse brain.

We have previously isolated from a human brain cDNA library, a new protein having two C2-like domains which interact with Ca2+ and phospholipid, and named Doc2alpha. Doc2alpha is abundantly expressed in brain, where it is highly concentrated on the synaptic vesicle fraction, and is implicated in Ca2(+)-dependent exocytosis. We have isolated here a mouse Doc2alpha cDNA and determined the localization of its mRNA in adult mouse brain. The amino acid sequence of the mouse Doc2alpha cDNA is 92% identical with that of the human counterpart. Northern blot analysis and in situ hybridization on adult mouse brain sections have revealed that Doc2alpha is predominantly expressed in mouse brain, where it is expressed in neuronal cells, but not in non-neuronal cells. Doc2alpha is highly expressed in the olfactory bulb, cerebral cortex, hippocampus, amygdaloid complex, and ventromedial hypothalamus nucleus, but not in the cerebellum, caudate-putamen, or ventral thalamus. These results indicate that Doc2alpha is expressed heterogeneously in mouse brain, where it is predominantly expressed in neuronal cells, and suggest that Doc2alpha plays a specific role in the area where it is expressed.

Amino Acid Sequence↗
PubMed1997

Comparison of tissue distribution of two novel serine/threonine kinase genes containing the LIM motif (LIMK-1 and LIMK-2) in the developing rat.

We previously isolated two novel serine/threonine kinase genes containing the LIM motif (LIMK-1 and LIMK-2) from a rat cDNA library. To examine the functions of these genes, we performed in situ hybridization in the developing rat nervous system. LIMK-1 and LIMK-2 mRNAs mostly co-localized during development and are expressed preferentially in the central nervous system during mid-to-late gestation but the signals decreased during the post-natal period. However, differential gene expression was observed in some nuclei in the CNS; LIMK-1 mRNA was intensely expressed in the facial motor nucleus, the hypoglossal nucleus, deep nuclei of the cerebellum and the layers 3, 5 and 6 of the adult cerebral cortex while only LIMK-2 mRNA was preferentially expressed in the some parts of the epithelium. In the nasal cavity, LIMK-1 and LIMK-2 mRNAs were expressed complementarily. Our results suggest that LIMK-1 and LIMK-2 may have different functions in these regions during development.

Aging↗
PubMed1997

LIM-homeodomain gene family in neural development.

In the present study, we isolated five murine LIM-homeodomain (LH) genes including a novel gene designated as L3 which is expressed specifically in the medial ganglionic eminence of the embryonic brain and the mesenchyme surrounding the oral cavity. The comparison of the expression domains in the embryonic forebrain using in situ hybridization histochemistry proved that three LH genes (LH-2, lim-1, and L3) share sharp boundaries. In addition to the prosomeric boundaries in the diencephalon, this gene family defines novel boundaries in the basal telencephalon, the mesencephalon, and the rhombencephalon. These mutually exclusive expression domains suggest that this family might be involved in controlling the early compartmentalization and boundary formation of the developing central nervous system.

Animals↗
PubMed1996

cDNA cloning of a novel membrane glycoprotein that is expressed specifically in glial cells in the mouse brain. LIG-1, a protein with leucine-rich repeats and immunoglobulin-like domains.

A cDNA encoding a protein designated as LIG-1 has been cloned and characterized. A fragment of this cDNA was found previously in a screen for genes up-regulated during neural differentiation in mouse P19 embryonal carcinoma cells. Comparative sequence analysis revealed LIG-1 to be a novel integral membrane glycoprotein (1091 amino acids) containing an extracellular region (794 amino acids) with a potential signal peptide, 15 leucine-rich repeats, 3 immnunoglobulin-like domains, and 7 potential N-glycosylation sites, a transmembrane region of 23 amino acids, and a cytoplasmic region of 274 amino acids. This protein, therefore, is a new member of both the leucine-rich repeat and the immunoglobulin superfamilies. Furthermore, Northern blot and in situ hybridization analyses showed LIG-1 gene expression to be predominantly in the brain, restricted to a small subset of glial cells such as Bergmann glial cells of the cerebellum and glial cells in the nerve fiber layer of the olfactory bulb. On the basis of its structural features and expression pattern, we propose that LIG-1 functions as a cell type-specific adhesion molecule or receptor at the glial cell surface, and plays a role in the nervous system in for example neuroglial differentiation, development, and/or maintenance of neural functions where it is expressed.

Animals↗
PubMed1996

Localization of bcl-2, bax, and bcl-x mRNAs in the developing inner ear of the mouse.

In situ hybridization was employed to study the expression of bcl-2 mRNA and its family members, bax and bcl-x mRNAs, in the developing inner ear. We found that in the cochlear structure, sensory epithelial cells, the spiral ganglion and stria vascularis expressed these mRNAs in postnatal period in a temporally similar manner, but in embryos, neither bax nor bcl-x mRNA were expressed in the sensory epithelium from embryonic day (E) 13 to 19. In contrast to these patterns, bcl-2 mRNA was expressed by E15 to E19, and the expression at E13 was below the lower limit of detection. Non-neuronal tissue (stria vascularis) also expressed these three transcripts during development. These results suggest that bcl-2 family members may be differentially involved in the differentiation of sensory epithelial cells, spiral ganglia, and stria vascularis. In particular, the differential expression patterns in the cochleovestibular neurons suggest that proliferating and differentiating neurons utilize distinct members of the bcl-2 family.

Animals↗
PubMed1996

Differential expression of LIM-homeodomain genes in the embryonic murine brain.

Homeobox-containing genes are associated with the control of various stages in embryogenesis. LIM-homeodomain genes have been implicated in the control of differentiation of specific cell types in both neuronal and non-neuronal tissues, yet there have been few studies comparing the expression domains of these genes in the developing brain of a single species. In the present study, we isolated murine LIM-homeodomain genes (LH-2, lim-1, and L3) by reverse transcription-polymerase chain reaction (RT-PCR) method and investigated their expression domains in the embryonic brain by in situ hybridization analysis. These mRNAs showed mutually exclusive expression patterns suggesting that these factors may be involved in region-specific differentiation in the developing brain.

Amino Acid Sequence↗
PubMed1996

L3, a novel murine LIM-homeodomain transcription factor expressed in the ventral telencephalon and the mesenchyme surrounding the oral cavity.

By reverse-transcription polymerase chain reaction method, we isolated a novel murine LIM-homeodomain gene, L3. In situ hybridization analyses revealed that L3 mRNA was localized to the ventral telencephalon and the mesenchyme surrounding the oral cavity of mouse embryo, suggesting that L3 may be involved in the region-specific differentiation of these areas.

Amino Acid Sequence↗
PubMed1996

Localization of mRNAs for Rlim-1, the rat Xlim-1 homolog, in the developing rat brain.

We studied the localization of Rlim-1 mRNAs, the rat Xlim-1 homolog, in the developing rat brain using in situ hybridization histochemistry. On embryonic day 13 (E13), strong signals were observed in the most superficial layer of the telencephalon, the zonalimitans intrathalamica, the ventral thalamus, some nuclei of the hypothalamus, the tectum, the cerebellum, the lower brainstem and the spinal cord. In the above-mentioned regions except the cerebellum, the distribution pattern remained almost the same from embryonic stage to adulthood but the intensity of expression gradually decreased after birth. In the cerebellum, the distribution pattern changed. during development; all the primordium of cerebellum in E13, the external granular and the Purkinje cell layers in postnatal day 7 (P7), and only the Purkinje cell layer in the adult expressed positive signals. These results suggest that Rlim-1 may be involved in region specification.

Animals↗
PubMed1996

Molecular cloning of novel leucine-rich repeat proteins and their expression in the developing mouse nervous system.

It is well established that leucine-rich repeat (LRR) proteins such as connectin, slit, chaoptin, and Toll have pivotal roles in neuronal development in Drosophila as cell adhesion molecules. However, to date, little information concerning mammalian LRR proteins has been reported. In the present study, we sought LRR proteins of the mouse brain, based on the assumption that fundamental mechanisms are conserved between different species. We screened a neonatal mouse brain cDNA library with a human partial cDNA encoding LRR protein as a probe. We obtained two independent cDNAs encoding LRR proteins, designated NLRR-1 and NLRR-2 (Neuronal Leucine-Rich Repeat proteins). We analyzed the whole sequence of NLRR-1 and partial sequence of NLRR-2. Sequence analysis showed that these two clones are about 60% homologous to each other, and that NLRR-1 protein is a transmembrane protein. Northern blot analysis and in situ hybridization histochemistry showed that both NLRR-1 and NLRR-2 mRNAs were expressed primarily in the central nervous system (CNS); NLRR-1 mRNA was also detected in the non-neuronal tissues such as cartilage, while NLRR-2 mRNA expression was confined to the CNS at all developmental stages. These results suggest that there is at least one LRR protein family in the mouse and that these molecules may play significant but distinct roles in neural development and in the adult nervous system.

Amino Acid Sequence↗
PubMed1996

Induction of SPI-3 mRNA, encoding a serine protease inhibitor, in gerbil hippocampus after transient forebrain ischemia.

We cloned genes the expression of which is induced in the Mongolian gerbil (Meriones unguiculatus) hippocampus after transient forebrain ischemia by a differential display technique. Among these genes, a rat serine protease inhibitor SPI-3 homologue was isolated. Present analyses suggested that the expression of gerbil SPI-3 mRNA was closely associated with delayed neuronal death and may block activities of proteases leaking from degenerating neurons or may support neuronal survival.

Amino Acid Sequence↗
PubMed1996

Increased expression of NLRR-3 mRNA after cortical brain injury in mouse.

In Drosophila, members of the leucine-rich repeat (LRR) family have significant functions in neural development. We have isolated mouse brain cDNAs which encode three new independent LRR proteins (neuronal leucine-rich repeat: NLRR-1, NLRR-2, NLRR-3). Levels of expression of these NLRR mRNAs were measured in a unilateral cortical injury model by in-situ hybridization and Northern blot analysis. In the injured cerebral cortex, only NLRR-3 mRNA increased in layers 2-3, while the other two genes showed no up-regulation. The level of NLRR-3 mRNA induction peaked around 7-10 days postinjury. This study suggests that NLRR-3 may be an important component of the pathophysiological response to brain injury.

Animals↗
PubMed1995

Localization of novel receptor tyrosine kinase genes of the eph family, MDK1 and its splicing variant, in the developing mouse nervous system.

In the course of studies to identify new members of the eph family of receptor tyrosine kinases, MDK1 and one of its splicing variants lacking a kinase domain, MDK1-T1, were identified. To gain insight into the functions of these subtypes, expression patterns of their mRNAs in the developing mouse nervous system were examined by Northern blotting and in situ hybridization histochemistry. Colocalization of their mRNAs was observed, but the levels of expression of each mRNA were developmentally regulated. These findings suggest functional differences between full-length and truncated forms of MDK1 receptor tyrosine kinase.

Animals↗