bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inhibition of type I procollagen production by tRNAVal CTE‐HSP47 ribozyme
Authors: Hagiwara Seiya , Nakamura Kiminori , Hamada Hirofumi , Sasaki Katsunori , Ito Yoshinori , Kuribayashi Kageaki , Sato Tsutomu , Sato Yasushi , Takahashi Minoru , Kogawa Katsuhisa , Kato Junji , Terui Takeshi , Takayama Tetsuji , Matsunaga Takuya , Taira Kazunari , Niitsu Yoshiro 
Published: August 2003

AbstractBackgroundFibrosis characteristically occurs in the advanced stages of chronic inflammatory diseases, occasionally as the primary lesion, and frequently determines the disease prognosis. Fibrotic lesions consist mostly of collagen, and therefore it may be possible to prevent or treat fibrosis by inhibiting collagen production. Of the currently available therapeutic approaches, however, none is sufficiently effective and specific for inhibition of collagen. Heat shock protein 47 (HSP47) is a collagen‐specific molecular chaperone that has been reported to play a pivotal role in secretion of procollagen molecules. Therefore, we have tried to suppress its function to inhibit these various types of collagen.MethodsWe have developed a novel type of ribozyme by ligating a hammerhead sequence to a tRNAVal promoter to facilitate displacing the ribozyme from nucleus to cytoplasm and to constitutive transport element, a binding motif of helicase which unwinds mRNA to render the target sequence on the mRNA accessible to the ribozyme.ResultsThe ribozyme thus constructed showed strong activity to cleave HSP47 mRNA and suppress the secretion of type I procollagen in the human primary fibroblast.ConclusionWe suggest applicability of this ribozyme as a new modality for antifibrosis therapy. Copyright © 2003 John Wiley & Sons, Ltd.
Ligation of exogenous linear DNA after gene transfer in vitro and in vivo
Authors: Rittner Karola , Benavente Annie , Jacobs Eric 
Published: August 2003

AbstractBackgroundWe have analyzed the physical/topographical state of linear exogenous DNA after gene transfer in vitro and in vivo.Methods and resultsLinear DNA carrying a luciferase expression cassette, either intact or corrupted within the coding region, was tested in gene transfer experiments in vitro and in vivo. To this, a plasmid with a CMV‐IE1 promoter‐driven luciferase gene was rendered non‐functional by the insertion of a 1.2 kb EcoRV–EcoRV fragment. After removal of the insert by digestion with EcoRV, the resulting linear DNA fragments were used to transfect HeLa cells. The recovery of luciferase activity from these cells indicated functional reconstitution of the expression cassette. Recovery of low molecular weight DNA from HeLa cells allowed amplification of an intact luciferase gene, confirming accurate ligation of free DNA ends. In the mouse, rapid intravenous injection of plasmid DNA, linearized within the luciferase gene, resulted in significant luciferase activities in liver and lung. Ligation products could be detected by PCR.ConclusionsThese data suggest that linear DNA is efficiently circularized after gene transfer in vitro and in vivo. Secondly, equally high luciferase activities were observed in the mouse after rapid intravenous injection of luciferase expression cassettes, either consisting of linear DNA produced by PCR, or carried by linearized plasmid DNA. These findings encourage the use of linear DNA elements for gene transfer applications in vivo. Copyright © 2003 John Wiley & Sons, Ltd.
Osteogenesis in rats induced by a novel recombinant helper‐dependent bone morphogenetic protein‐9 (BMP‐9) adenovirus
Authors: Li Jin Zhong , Hankins Gerald R. , Kao Chinghai , Li Hongwei , Kammauff John , Helm Gregory A. 
Published: August 2003

AbstractBackgroundAlthough recombinant first‐generation BMP adenoviruses can induce ectopic bone formation in immune deficient animals, the osteoinductive activity of these BMP vectors is reduced in immune competent animals. Helper‐dependent adenoviral vectors have been developed to decrease the immune response and, therefore, increase gene expression in immune competent animals compared with first‐generation vectors. In the present study, the osteoinductive activity of a helper‐dependent GFP and BMP‐9 adenoviral vector (ADGBMP9) was evaluated in vitro and in vivo.MethodsInitially, purified ADGBMP9 was used to transduce human mesenchymal stem cells (hMSCs) and the alkaline phosphatase activity was determined as a measure of osteogenic activity. The vector was then injected into the thigh muscle of athymic nude and Sprague‐Dawley rats, and CT scans and histology were subsequently used to assess bone formation.ResultsIn vitro, ADGBMP9 was capable of inducing alkaline phosphatase expression in hMSCs. In vivo in athymic nude and Sprague Dawley rats, ADGBMP9 initiated the process of bone formation 3 days after percutaneous injection into the thigh musculature. The rats demonstrated intramuscular ectopic ossification in CT scans as early as day 9 post viral injection and ultimately formed significant amounts of ectopic bone. Histologically, the induced bone was formed via normal endochondral mechanisms.ConclusionsA helper‐dependent adenoviral vector containing the BMP‐9 and GFP genes has significant osteoinductive activity in both athymic nude and immune competent rats. Additional direct and ex vivo BMP gene therapy studies are required to assess the vector's activity in more animal models. Copyright © 2003 John Wiley & Sons, Ltd.
IONP‐PLL: a novel non‐viral vector for efficient gene delivery
Authors: Xiang Juan‐Juan , Tang Jing‐Qun , Zhu Shi‐Guo , Nie Xin‐Min , Lu Hong‐Bin , Shen Shou‐Rong , Li Xiao‐Ling , Tang Ke , Zhou Ming , Li Gui‐Yuan 
Published: August 2003

AbstractBackgroundNon‐viral methods of gene delivery have been an attractive alternative to virus‐based gene therapy. However, the vectors that are currently available have drawbacks limiting their therapeutic application.MethodsWe have developed a self‐assembled non‐viral gene carrier, poly‐L‐lysine modified iron oxide nanoparticles (IONP‐PLL), which is formed by modifying poly‐L‐lysine to the surface of iron oxide nanoparticles. The ability of IONP‐PLL to bind DNA was determined by ratio‐dependent retardation of DNA in the agarose gel and co‐sedimentation assay. In vitro cytotoxic effects were quantified by MTT assay. The transfection efficiency in vitro was evaluated by delivering exogenous DNA to different cell lines using IONP‐PLL. Intravenous injection of IONP‐PLL/DNA complexes into mice was evaluated as a gene delivery system for gene therapy. The PGL2‐control gene encoding firefly luciferase and the EGFP‐C2 gene encoding green fluorescent protein were used as marker genes.ResultsIONP‐PLL could bind and protect DNA. In contrast to PLL and cationic liposomes, IONP‐PLL described here was less cytotoxic in a broad range of concentrations. In the current study, we have demonstrated that IONP‐PLL can deliver exogenous gene to cells in vitro and in vivo. After intravenous injection, IONP‐PLL transferred reporter gene EGFP‐C2 to lung, brain, spleen and kidney. Furthermore, we have demonstrated that IONP‐PLL transferred exogenous DNA across the blood‐brain barrier to the glial cells and neuron of brain.ConclusionsIONP‐PLL, a low‐toxicity vector, appears to have potential for fundamental research and genetic therapy in vitro and in vivo, especially for gene therapy of CNS disease. Copyright © 2003 John Wiley & Sons, Ltd.
Intravenous bone marrow stromal cell therapy reduces apoptosis and promotes endogenous cell proliferation after stroke in female rat
Authors: Chen Jieli , Li Yi , Katakowski Mark , Chen Xiaoguang , Wang Lei , Lu Dunyue , Lu Mei , Gautam Subhash C. , Chopp Michael 
Published: August 2003

AbstractThe present study investigates the induction of neurogenesis, reduction of apoptosis, and promotion of basic fibroblast growth factor (bFGF) expression as possible mechanisms by which treatment of stroke with bone marrow stromal cells (MSCs) improves neurological functional recovery. Additionally, for the first time, we treated cerebral ischemia in female rats with intraveneous administration of MSCs. Female rats were subjected to 2 hr of middle cerebral artery occlusion (MCAo), followed by an injection of 3 × 106 male (for Y chromosome labeling) rat MSCs or phosphate‐buffered saline (PBS) into the tail vein 24 hr after MCAo. All animals received daily injection of bromodeoxyuridine (BrdU; 50 mg/kg, i.p.) for 13 days after treatment for identification of newly synthesized DNA. Animals were sacrificed at 14 days after MCAo. Behavioral tests (rotarod and adhesive‐removal tests) were performed. In situ hybridization, immunohistochemistry, and terminal deoxynucleotidyltransferase (TdT)‐mediated dUTP‐biotin nick‐end labeling (TUNEL) were performed to identify transplanted MSCs (Y chromosome), BrdU, bFGF, and apoptotic cells in the brain. Significant recovery of behavior was found in MSC‐treated rats at 7 days in the somatosensory test and at 14 days in the motor test after MCAo compared with control, PBS‐treated animals (P < .05). MSCs were found to survive and preferentially localize to the ipsilateral ischemic hemisphere. Significantly more BrdU‐positive cells were located in the subventricular zone (P < .05), and significantly fewer apoptotic cells and more bFGF immunoreactive cell were found in the ischemic boundary area (P < .05) of MSC‐treated rats than in PBS‐treated animals. Here we demonstrate that intravenously administered male MSCs increase bFGF expression, reduce apoptosis, promote endogenous cellular proliferation, and improve functional recovery after stroke in female rats. © 2003 Wiley‐Liss, Inc.
Dysfunctional oligodendrocyte progenitor cell (OPC) populations may inhibit repopulation of OPC depleted tissue
Authors: Chari D.M. , Huang W.L. , Blakemore W.F. 
Published: August 2003

AbstractWe have attempted to extend a previously described rat model of focal oligodendrocyte progenitor cell (OPC) depletion, using 40 Gy X‐irradiation (Chari and Blakemore [2002] Glia 37:307–313), to the adult mouse spinal cord, to examine the ability of OPCs present in adjacent normal areas to colonise areas of progenitor depletion. In contrast to rat, OPCs in the mouse spinal cord appeared to be a comparatively radiation‐resistant population, as 30–35% of OPCs survived in X‐irradiated tissue (whereas <1% of OPCs survive in X‐irradiated rat spinal cord). The numbers of surviving OPCs remained constant with time indicating that this population was incapable of regenerating itself in response to OPC loss. Additionally, these OPCs did not contribute to remyelination of axons when demyelinating lesions were placed in X‐irradiated tissue, suggesting that the surviving cells are functionally impaired. Importantly, the length of the OPC‐depleted area did not diminish with time, as would be expected if progressive repopulation of OPC‐depleted areas by OPCs from normal areas was occurring. Our findings therefore raise the possibility that the presence of a residual dysfunctional OPC population may inhibit colonisation of such areas by normal OPCs. © 2003 Wiley‐Liss, Inc.
Glia‐conditioned medium induces de novo synthesis of tyrosine hydroxylase and increases dopamine cell survival by differential signaling pathways
Authors: de Bernardo S. , Canals S. , Casarejos M. J. , Rodriguez‐Martin E. , Mena M. A. 
Published: August 2003

AbstractThe mesencephalic astroglia‐conditioned medium (GCM) greatly increases dopamine (DA) phenotype expression, and it also protects from spontaneous and toxin‐induced cell death in midbrain cultures. In this study, we have investigated the signaling pathways implicated in those effects. Genistein at 5 μM, an inhibitor of tyrosine kinase receptors, and KT‐5720, a protein kinase A inhibitor, blocked the GCM‐induced effects on DA phenotype expression and DA cell survival but did not abolish the increased astrocytic (glial fibrillary acidic protein‐positive; GFAP+) processes. We analyzed the role of phosphatidylinositol‐3 kinase (PI‐3K) on TH induction and cell survival, with the PI‐3K inhibitors LY‐294002 and wortmannin, and the role of the phosphorylation of mitogen‐activated protein kinase (MAPK) with PD‐98059, a p‐ERK1/2 MAPK inhibitor. LY‐294002 at 20–30 μM blocked the GCM‐induced effects on TH expression and DA cell survival but did not abolish the increased astrocytic processes. PD‐98059 at 20 and 40 μM blocked the GCM‐induced effects on DA phenotype, cell survival, and GFAP expression. However, staurosporine at 10 nM, a protein kinase C inhibitor, only blocked the protective effects induced by GCM on midbrain cell apoptosis. The data presented herein show that tyrosine kinase receptors, cAMP‐dependent protein kinase, PI‐3K, and MAPK signaling pathways are implicated in de novo synthesis of TH+cells induced by GCM as well as in DA cell apoptosis and that these effects are unrelated to increased GFAP expression. PKC inhibitors only abolished the GCM‐induced effects on midbrain neuronal survival, suggesting that signaling pathways for DA phenotype expression and survival may be independent. © 2003 Wiley‐Liss, Inc.
Dietary lithium induces regional increases of mRNA encoding cysteine string protein in rat brain
Authors: Cordeiro Mara L. , Gundersen Cameron B. , Umbach Joy A. 
Published: August 2003

AbstractLithium salts are used to treat manic‐depressive disorders; however, the mechanism by which lithium produces its therapeutic benefit remains obscure. The action of lithium may involve alterations of proteins important for regulating synaptic function. In this context, we observed recently that lithium at therapeutically relevant concentrations enhanced expression of cysteine string protein (csp) at the level of both mRNA and protein, in cell culture and in rat brain. Several lines of evidence have shown that csps are vital components of the regulated secretory pathway. We were interested whether lithium modulates expression of csp in specific brain regions. To study this issue, we analyzed the effects of chronic lithium administration (21 days) on csp mRNA levels in rat brain using in situ hybridization. Densitometric analysis revealed that lithium upregulated csp mRNA in several brain areas that are important for mood and behavior. This effect may be germane to understanding the beneficial action of lithium in mood disorders. © 2003 Wiley‐Liss, Inc.
Selective disappearance of an axonal protein, 440‐kDa ankyrinB, associated with neuronal degeneration induced by methylmercury
Authors: Sakaue Motoharu , Takanaga Hiromi , Adachi Tatsumi , Hara Shuntaro , Kunimoto Manabu 
Published: August 2003

AbstractThe 440‐kDa isoform of brain ankyrin, 440‐kDa ankyrinB, is a neuron‐specific protein and is confined to axons. Cerebellum is one of the areas characteristically altered by methylmercury intoxication both in the adult and during development. When rat cerebellar neurons matured for 7 days in vitro were exposed to methylmercury at 0.03 μM for 48 hr, viability of the cells was unaffected. However, the immunocytochemical staining of 440‐kDa ankyrinB diminished drastically, whereas that of microtubule‐associated protein‐2, which is localized in dendrites and cell bodies, and of glial fibrillary acidic protein (GFAP), a marker for astroglial cells coexisting in the culture, remained unchanged. To confirm these observations, a simplified dot blot assay was established to determine 440‐kDa ankyrinB and several other marker proteins in cultured cell samples. With this assay, we found that methylmercury at a submicromolar range induced a decrease of 440‐kDa ankyrinB and an increase of GFAP in a dose‐dependent manner in cerebellar cells in primary culture. Surprisingly, another axonal protein, tau, remained mostly in its intact molecular sizes even in the presence of 0.3–1.0 μM methylmercury, though its immunocytochemical localization was substantially altered. These results indicate that selective loss of the axonal protein 440‐kDa ankyrinB is associated with the early stage of degeneration of cerebellar neurons induced by methylmercury. Therefore, 440‐kDa ankyrinB should be useful as a specific and sensitive marker for the neurotoxicity of methylmercury. © 2003 Wiley‐Liss, Inc.
Targeted transgene expression in rat brain using lentiviral vectors
Authors: Jakobsson Johan , Ericson Cecilia , Jansson Maria , Björk Elin , Lundberg Cecilia 
Published: August 2003

AbstractDirect gene transfer to the adult brain is dependent on vectors that transduce non‐dividing cells, such as lentiviral vectors. Another aspect of the development of gene therapy to the brain is the need for cell‐specific transgene expression. Expression from vesicular stomatitis virus G‐protein (VSV‐G) pseudotyped lentiviral vectors has been reported to be mainly neuron specific in the brain. We constructed cell‐specific lentiviral vectors using the neuron‐specific enolase (rNSE) or the glial fibrillary acidic protein (hGFAP) promoters and compared them to the ubiquitous human cytomegalovirus promoter (hCMV), a hybrid CMV/β‐actin promoter (CAG) and the promoter for human elongation factor 1α (EF1α). Our results showed that the hGFAP promoter was expressed only in glial cells, whereas rNSE was purely neuron specific, showing that VSV‐G is pantropic in the rat striatum. We conclude that the VSV‐G allows transduction of both glial and neuronal cells and the promoter dictates in what cell type the transgene will be expressed. The expression of transgenes exclusively in astrocytes would allow for local delivery of secreted transgene products, such as glial cell line‐derived neurotrophic factor (GDNF), circumventing the anterograde transport that may induce unwanted side effects. © 2003 Wiley‐Liss, Inc.
Caspase activity is essential for long‐term potentiation
Authors: Gulyaeva Natalia V. , Kudryashov Igor E. , Kudryashova Irina V. 
Published: August 2003

AbstractSlices from rat hippocampus were incubated with the caspase‐3 inhibitor N‐benzyloxycarbonyl‐Asp‐Glu‐Val‐Asp fluoromethylketone (Z‐DEVD‐FMK) or with the inactive peptide N‐benzyloxycarbonyl‐Phe‐Ala fluoromethylketone (Z‐Phe‐Ala‐FMK) for 30 min. The peptides changed neither input–output curves nor paired‐pulse effects at 70‐msec interpulse intervals, nor amplitudes of pop spikes in the CA1 region 1.0–6.9 hr after the incubation. Slices taken 1.0–1.4 hr after Z‐DEVD‐FMK or inactive peptide treatment demonstrated similar long‐term potentiation (LTP) curves; however, LTP was suppressed significantly (P < 0.001) 1.5–3.4 hr after Z‐DEVD‐FMK treatment when compared to the corresponding inactive peptide group. LTP magnitude correlated with time after Z‐DEVD‐FMK (r = −0.74; P < 0.02) but did not depend on time after the inactive peptide treatment. After 3.5 hr, LTP was blocked completely. Z‐DEVD‐FMK did not have a significant effect on presynaptic function. The results are the first evidence that inhibition of caspase‐3 significantly decreases or fully blocks LTP in the CA1 region and suggest that caspase‐3 is essential for LTP. Candidate caspase‐3 substrates that may be cleaved for LTP induction and maintenance are discussed. © 2003 Wiley‐Liss, Inc.
Relationship between NMDA receptor expression and MPP+ toxicity in cultured dopaminergic cells
Authors: Church William H. , Hewett Sandra J. 
Published: August 2003

AbstractIt has been suggested that excitotoxicity could be contributing to dopamine cell loss after methylphenylpyridinium ion (MPP+) exposure, although the literature regarding this is contradictory. Given that in cell culture excitotoxicity has been reported to be dependent on culture age, we postulated that these discrepant results might be explained by a difference in developmental expression of N‐methyl‐D‐aspartate (NMDA) receptors. To test this, mesencephalic cells were cultured and the number of dopaminergic neurons (tyrosine hydroxylase‐immunoreactive cells [TH‐IR] cells) expressing the NMDA R1 subunit (NR1) was determined using double‐label immunofluorescence microscopy. An increase in the percentage of TH‐IR cells expressing NR1 occurred over time in culture and this correlated with the toxicity of NMDA. At 7 days in vitro (DIV 7), only 17% (n = 167 cells/4 experiments) of TH‐IR cells expressed NR1 and these cells were insensitive to NMDA toxicity. This increased to 80% (n = 254 cells/6 experiments) by DIV 11 and cultures were now susceptible to NMDA‐induced injury. Cultures grown for either 7 or 11 days were treated for 48 hr with increasing concentrations of MPP+ (0.5–20 μM) and the loss of dopaminergic neurons was determined by cell counting. Cultures at DIV 7 were more sensitive to MPP+ than 11‐day‐old cultures (LD50 = ∼0.75 μM vs. 15 μM, respectively). Co‐exposure to MK‐801 (5 μM) did not protect against MPP+ toxicity in young cultures, but attenuated MPP+ toxicity in the older cultures, becoming statistically significant at 20 μM MPP+. These data indicate that the activation of NMDA receptors is not required for, but can contribute to, MPP+‐induced neurodegeneration of dopaminergic cells in culture. © 2003 Wiley‐Liss, Inc.
Palaeoecological evidence of changes in vegetation and climate during the Holocene in the pre‐Polar Urals, northeast European Russia
Authors: Kultti Seija , Väliranta Minna , Sarmaja‐Korjonen Kaarina , Solovieva Nadia , Virtanen Tarmo , Kauppila Tommi , Eronen Matti 
Published: August 2003

AbstractThis study investigated Holocene tree‐line history and climatic change in the pre‐Polar Urals, northeast European Russia. A sediment core from Mezhgornoe Lake situated at the present‐day alpine tree‐line was studied for pollen, plant macrofossils, Cladocera and diatoms. A peat section from Vangyr Mire in the nearby mixed mountain taiga zone was analysed for pollen. The results suggest that the study area experienced a climatic optimum in the early Holocene and that summer temperatures were at least 2°C warmer than today. Tree birch immigrated to the Mezhgornoe Lake area at the onset of the Holocene. Mixed spruce forests followed at ca. 9500–9000 14C yr BP. Climate was moist and the water level of Mezhgornoe Lake rose rapidly. The hypsithermal phase lasted until ca. 5500–4500 14C yr BP, after which the mixed forest withdrew from the Mezhgornoe catchment as a result of the climate cooling. The gradual altitudinal downward shift of vegetation zones resulted in the present situation, with larch forming the tree‐line. Copyright © 2003 John Wiley & Sons, Ltd.
Radiocarbon constraints on the Holocene flood deposits of the Ning‐Zhen Mountains, lower Yangtze River area of China
Authors: Yu Shi‐Yong , Zhu Cheng , Wang Fubao 
Published: August 2003

AbstractLying athwart both the temperate and subtropical zones, the Ning‐Zhen Mountains are particularly prone to extreme floods in the summer months when cold fronts collide with the subtropics‐derived warm airmasses. The Holocene flood deposits in the region may provide a long‐term perspective on hydrographical change and its palaeoclimatic implications. Radiocarbon dates on carbonised wood preserved in flooding sediments reveal that the region has experienced a number of catastrophic floods throughout the middle Holocene. These extreme flooding events cluster into three periods: (i) 9200–8200 cal. yr BP, (ii) 7600–5800 cal. yr BP and (iii) 5200–4000 cal. yr BP, corresponding to the times when the East Asian monsoon has been intensified under warm conditions. The significant falls in flooding frequency around 8200 cal. yr BP, 5800 cal. yr BP and 4000 cal. yr BP may have resulted from substantial reduction in regional precipitation, probably associated with meridional displacement of the planetary frontal system. Copyright © 2003 John Wiley & Sons, Ltd.