bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enhanced angiogenesis characteristic of SPARC‐null mice disappears with age
Authors: Reed May J. , Bradshaw A.D. , Shaw M. , Sadoun E. , Han N. , Ferara N. , Funk S. , Puolakkainen P. , Sage E.H. 
Published: March 2005

AbstractThe impairment of angiogenesis in aging has been attributed, in part, to alterations in proteins associated with the extracellular matrix (ECM). SPARC (secreted protein acidic and rich in cysteine/osteonectin/BM‐40) is a matricellular protein that regulates endothelial cell function as well as cell–ECM interactions. We have previously shown that angiogenesis, as reflected by fibrovascular invasion into subcutaneously implanted polyvinyl alcohol (PVA) sponges, is increased in SPARC‐null mice (6–9 months of age) relative to their wild‐type (WT) counterparts. In this study, we define the influence of aging on (a) the expression of SPARC and (b) fibrovascular invasion into sponge implants in SPARC‐null and WT mice. The expression of SPARC in fibroblasts and endothelial cells derived from young donors (humans mean age less than 30 years and mice 4–6 months of age) and old donors (humans mean age over 65 years and mice 22–27 months of age) decreased 1.6 to 2.3‐fold with age. Analysis of fibrovascular invasion into sponges implanted into old (22–27 months) SPARC‐null and WT mice showed no differences in percent area of invasion or collagenous ECM. Moreover, sponges from old SPARC‐null and WT mice contained similar levels of VEGF that were significantly lower than those from young (4–6 months) mice. In contrast to fibroblasts from young SPARC‐null mice, dermal fibroblasts from old SPARC‐null mice did not migrate farther, proliferate faster, or produce greater amounts of VEGF relative to their old WT counterparts. However, when stimulated with TGF‐β1, primary cells isolated from the sponge implants, and dermal fibroblasts from both old SPARC‐null and WT mice, showed marked increases in VEGF secretion. These data indicate that aging results in a loss of enhanced angiogenesis in SPARC‐null mice, as a result of the detrimental impact of age on cellular functions, collagen deposition, and VEGF synthesis. However, the influence of aging on these processes may be reversed, in part, by growth factor stimulation. © 2005 Wiley‐Liss, Inc.
Inhibition of Cdk6 expression through p38 MAP kinase is involved in differentiation of mouse prechondrocyte ATDC5
Authors: Moro Toru , Ogasawara Toru , Chikuda Hirotaka , Ikeda Toshiyuki , Ogata Naoshi , Maruyama Zenjiro , Komori Toshihisa , Hoshi Kazuto , Chung Ung‐Il , Nakamura Kozo , Okayama Hiroto , Kawaguchi Hiroshi 
Published: March 2005

AbstractBecause a temporal arrest in the G1‐phase of the cell cycle is a prerequisite for cell differentiation, this study investigated the involvement of cell cycle factors in the differentiation of cultured mouse prechondrocyte cell line ATDC5. Among the G1 cell cycle factors examined, both protein and mRNA levels of cyclin‐dependent kinase (Cdk6) were downregulated during the culture in a differentiation medium. The protein degradation of Cdk6 was not involved in this downregulation because proteasome inhibitors did not reverse the protein level. When inhibitors of p38 MAPK, ERK‐1/2, and PI3K/Akt were added to the culture, only a p38 MAPK inhibitor SB203580 blocked the decrease in the Cdk6 protein level by the differentiation medium, indicating that the Cdk6 inhibition was mediated by p38 MAPK pathway. In fact, p38 MAPK was confirmed to be phosphorylated during differentiation of ATDC5 cells. Enforced expression of Cdk6 in ATDC5 cells blocked the chondrocyte differentiation and inhibited Sox5 and Sox6 expressions. However, the Cdk6 overexpression did not affect the proliferation or the cell cycle progression, suggesting that the inhibitory effect of Cdk6 on the differentiation was exerted by a mechanism largely independent of its cell cycle regulation. These results indicate that Cdk6 may be a regulator of chondrocyte differentiation and that its p38‐mediated downregulation is involved in the efficient differentiation. © 2005 Wiley‐Liss, Inc.
Docosahexaenoic acid induces apoptosis in proliferating human endothelial cells
Authors: Kim Hyo Jung , Vosseler Claudia A. , Weber Peter C. , Erl Wolfgang 
Published: March 2005

Abstractn‐3 polyunsaturated fatty acids (PUFAs) have been shown to exert beneficial effects in the prevention of cardiovascular disease, inflammation, and on tumor growth. To investigate effects of PUFAs on proliferation and apoptosis in endothelial cells, we tested the n‐3 PUFA docosahexaenoic acid (DHA) and the n‐6 PUFA arachidonic acid (AA) in human umbilical vein endothelial cells (HUVEC). The mitochondrial membrane potential (MMP) and the production of reactive oxygen species were examined by flow cytometry. Phosphorylation of p53 or p38 MAP kinase, and total levels of p53 were measured by Western blot. DNA binding activity of p53 was analyzed with a TransAM transcription factor assay kit. Tube formation was assessed on Matrigel. In proliferating HUVEC, but not in confluent cells, DHA reduced cell viability and induced apoptosis, as demonstrated by increases in membrane leakage (propidium iodide (PI) staining), Annexin‐V binding, sub G1 phase in the cell cycle, and TUNEL‐positive cells. AA had no effect on these parameters. In addition to a reduced MMP and increased reactive oxygen species, phosphorylation of p38 and p53 (serine 15) and impaired DNA binding of p53 were observed. There was no change in total levels of p53. The p38 inhibitor SB203580 had no effect on Annexin V binding. DHA also attenuated HUVEC tube formation. Taken together, DHA induces apoptosis in proliferating, but not in resting HUVEC, potentially via the phosphorylation of p53, resulting in decreased p53 DNA binding. The results suggest that anti‐angiogenic effects of DHA may be due to induction of apoptosis in proliferating endothelial cells. © 2005 Wiley‐Liss, Inc.
Dominant expression of androgen receptors and their functional regulation of organic anion transporter 3 in rat brain capillary endothelial cells; Comparison of gene expression between the blood–brain and ‐retinal barriers
Authors: Ohtsuki Sumio , Tomi Masatoshi , Hata Toshio , Nagai Yoko , Hori Satoko , Mori Shinobu , Hosoya Ken‐ichi , Terasaki Tetsuya 
Published: March 2005

AbstractBrain and retinal capillary endothelial cells (BCECs and RCECs, respectively) exhibit a barrier structure and function. Comparison of gene expression in these cells could clarify the selective function of each barrier. The purpose of this study was to identify the genes selectively expressed at the blood–brain barrier (BBB) and to clarify the function of the selective gene, androgen receptor (AR). Gene expression was compared by a differential display using conditionally immortalized rat BCECs and RCECs (TR‐BBB and TR‐iBRB, respectively). A total of 12 gene fragments were identified as the selective genes dominantly expressed in TR‐BBB cells. The most selective fragment in TR‐BBB cells had the highest homology with the 3′‐UTR of human and mouse AR. Rat AR mRNA was detected in TR‐BBB cells and the brain capillary rich fraction, but not in TR‐iBRB cells. Expression of organic anion transporter 3 (OAT3) mRNA in TR‐BBB cells was induced by treatment with dihydrotestosterone (DHT), an AR ligand, and this induction was suppressed by flutamide. Moreover, uptake of benzylpenicillin by TR‐BBB cells was also induced by DHT treatment. In contrast, OAT3 mRNA expression in TR‐iBRB cells was not affected by DHT treatment. The brain‐to‐blood efflux rate of benzylpenicillin was not affected by gender. These results suggest that AR is involved in the functional regulation of OAT3 at the BBB, but not at the inner blood‐retinal barrier (iBRB), and this regulation is not affected by gender. The BBB function will be affected by the androgen levels in the brain and/or plasma via AR. © 2005 Wiley‐Liss, Inc.
BT‐IgSF, a novel immunoglobulin superfamily protein, functions as a cell adhesion molecule
Authors: Harada Hideki , Suzu Shinya , Hayashi Yokichi , Okada Seiji 
Published: March 2005

AbstractBT‐IgSF is a newly identified cell surface glycoprotein belonging to the immunoglobulin superfamily (IgSF). We have previously shown that the expression of the BT‐IgSF gene was highly restricted to brain and testis, and its transcript was detected in both neurons and glial cells. In this study, to explore its function, we generated cells overexpressing BT‐IgSF proteins and analyzed their phenotypes. We found that the constitutive expression of BT‐IgSF in the myeloid leukemia cell line TF‐1‐fms did not alter the growth rates, but caused the formation of large cell aggregates. The cell aggregates were also observed with mutant BT‐IgSF lacking its cytoplasmic tail, the amino acid sequences of which were highly conserved among the BT‐IgSF subgroup proteins. The neutralizing antibody to β1 integrin did not diminish the cell aggregate formation. These results indicate that BT‐IgSF functions as a cell adhesion molecule, that its cytoplasmic tail is not essential for the function, and that β1 integrin is not involved in the function. We confirmed the cell adhesion function using NIH/3T3 fibroblastic cells expressing BT‐IgSF in an inducible system. Flow cytometric analyses with the cells demonstrated that the cell aggregation mediated by BT‐IgSF was through homophilic molecular interaction, and in a Ca2+/Mg2+‐independent manner. Coupled with its restricted pattern of the expression, the cell adhesion‐inducing function of BT‐IgSF suggests a role of the cell surface molecule in the development/function of the central nervous system and spermatogenesis. © 2005 Wiley‐Liss, Inc.
Coloring graphs from lists with bounded size of their union
Authors: Král' Daniel , Sgall Jiří 
Published: March 2005

AbstractA graph G is k‐choosable if its vertices can be colored from any lists L(ν) of colors with |L(ν)| ≥ k for all ν ∈ V(G). A graph G is said to be (k,ℓ)‐choosable if its vertices can be colored from any lists L(ν) with |L(ν)| ≥k, for all ν∈ V(G), and with $|\bigcup_{{\nu}\in V(G)}\, L(\nu)|\le \ell$. For each 3 ≤ k ≤ ℓ, we construct a graph G that is (k,ℓ)‐choosable but not (k,ℓ + 1)‐choosable. On the other hand, it is proven that each (k,2k − 1)‐choosable graph G is O(k · ln k · 24k)‐choosable. © 2005 Wiley Periodicals, Inc. J Graph Theory
Validated toxicological determination of 30 drugs of abuse as optimized derivatives in oral fluid by long column fast gas chromatography/electron impact mass spectrometry
Authors: Gunnar Teemu , Ariniemi Kari , Lillsunde Pirjo 
Published: April 2005

AbstractAn analytical procedure was developed for the simultaneous sensitive identification, screening and quantitation of 30 drugs of abuse using 250 µl of human oral fluid. The method employs sequential mixed‐mode solid‐phase extraction (SPE), optimized derivative formation and long‐column fast gas chromatography/electron impact mass spectrometry (GC/EI‐MS). After sequential SPE elution, the most sensitive and stable derivatives were formed by taking careful account of the characteristics of the active functional groups and possible steric hindrances affecting derivatization chemistry. Amphetamine‐type stimulant drugs were acylated with heptafluorobutyric anhydride, benzodiazepines and Δ9‐tetrahydrocannabinol were silylated with N‐methyl‐N‐(tert‐butyldimethylsilyl)trifluoroacetamide and benzoylecgonine, codeine, ethylmorphine, 6‐monoacetylmorphine, morphine, pholcodine, buprenorphine and norbuprenorphine with N‐methyl‐N‐(trimethylsilyl)trifluoroacetamide. In addition, the following analytes were included: methadone, cocaine, alprazolam, midazolam, fentanyl and zolpidem. In GC separation, fast temperature ramping and high carrier gas flow‐rate combined with long 30 m columns of i.d. 0.32 mm offered a reduction in analysis time and sharp peak shapes while still maintaining sufficient resolution and high sample capacity. Validated parameters including selectivity, linearity, accuracy, intra‐ and inter‐day precision, extraction efficiency and limit of quantitation were all within required limits. In contrast to previously published methods, this single procedure is suitable for the simultaneous toxicological determination of the most common illicit drugs and benzodiazepines, and also zolpidem, in a small amount of oral fluid. Copyright © 2005 John Wiley & Sons, Ltd.
Temporal profiling of gene expression during neurogenesis and remodeling in the olfactory epithelium at short intervals after target ablation
Authors: Getchell Thomas V. , Liu Hua , Vaishnav Radhika A. , Kwong Kevin , Stromberg Arnold J. , Getchell Marilyn L. 
Published: March 2005

AbstractNeurogenesis in the olfactory epithelium (OE) is induced by olfactory bulbectomy (OBX), which effectively axotomizes olfactory sensory neurons (OSNs) and removes their synaptic targets, resulting in apoptosis. We used Affymetrix high‐density oligonucleotide arrays to investigate changes in gene expression during initiation of signaling in pathways that regulate apoptosis and neurogenesis in the murine OE at 2, 8, 16, and 48 hr after bilateral OBX compared to that in sham‐operated controls. We focused on regulation of a defined set of genes associated with apoptosis, stem/progenitor cell regulation, and cell cycle progression because of the activation of these processes in OE degeneration and remodeling after OBX. After data scrubbing and categorical analysis, one‐way analysis of variance identified 72 genes (4.9% of the present known genes) as being regulated significantly (P < 0.05) at one or more points; 50 were defined as regulated differentially with the false discovery rate at 10%. Significant changes in gene expression occurred in all categories as early as 2 hr post‐OBX, with the greatest number of differentially regulated genes at 16 and 48 hr. Hierarchical cluster analysis and correlation coefficients were used to identify similarities in patterns of gene expression changes within and across categories. Validation was carried out with SuperArray macroarrays and real‐time RT‐PCR. Our results confirmed the participation of many genes in known signaling pathways and identified changes in the expression of 42 genes not identified previously as participating in apoptosis and neurogenesis in the OE. Additionally, our analyses indicated the early involvement of genes regulating cytoskeletal reorganization and angiogenesis in the response to OBX. These studies are an important first step in defining early time‐dependent changes in gene expression after target ablation that lead to neurogenesis in the olfactory sensory epithelium. © 2005 Wiley‐Liss, Inc.
Tau is not normally degraded by the proteasome
Authors: Feuillette Sébastien , Blard Olivier , Lecourtois Magalie , Frébourg Thierry , Campion Dominique , Dumanchin Cécile 
Published: March 2005

AbstractTau‐positive inclusions in neurons are consistent neuropathologic features of the most common causes of dementias such Alzheimer's disease and frontotemporal dementia. Ubiquitinated tau‐positive inclusions have been reported in brains of Alzheimer's disease patients, but involvement of the ubiquitin‐dependent proteasomal system in tau degradation remains controversial. Before considering the tau degradation in pathologic conditions, it is important to determine whether or not endogenous tau is normally degraded by the proteasome pathway. We therefore investigated this question using two complementary approaches in vitro and in vivo. Firstly, SH‐SY5Y human neuroblastoma cells were treated with different proteasome inhibitors, MG132, lactacystin, and epoxomicin. Under these conditions, neither total nor phosphorylated endogenous tau protein levels were increased. Instead, an unexpected decrease of tau protein was observed. Secondly, we took advantage of a temperature‐sensitive mutant allele of the 20S proteasome in Drosophila. Genetic inactivation of the proteasome also resulted in a decrease of tau levels in Drosophila. These results obtained in vitro and in vivo demonstrate that endogenous tau is not normally degraded by the proteasome. © 2005 Wiley‐Liss, Inc.
Prospective characterization of neural stem cells by flow cytometry analysis using a combination of surface markers
Authors: Nagato Masako , Heike Toshio , Kato Takeo , Yamanaka Yasunari , Yoshimoto Momoko , Shimazaki Takuya , Okano Hideyuki , Nakahata Tatsutoshi 
Published: March 2005

AbstractNeural stem cells (NSCs) with self‐renewal and multilineage differentiation properties can potentially repair degenerating or damaged neural tissue. Here, we have enriched NSCs from neurospheres, which make up a heterogeneous population, by fluorescence‐activated cell sorting (FACS) with antibodies against syndecan‐1, Notch‐1, and integrin‐β1, which were chosen as candidates for hematopoietic cell—or somatic stem cell—markers. Antigen‐positive cells readily initiated neurosphere formation, but cells lacking these markers did so less readily. Doubly positive cells expressing both syndecan‐1 and Notch‐1 underwent neurosphere formation more efficiently than did singly positive cells. The progeny of sorted cells could differentiate into neurons and glial cells both in vitro and in vivo. These antibodies were also useful for isolating cells from the murine embryonic day 14.5 brain that efficiently formed neurospheres. In contrast, there was no distinct difference in neurosphere formation efficiency between Hoechst 33342‐stained side population cells and main population cells, although the former are known to have a stem cell phenotype in various tissues. These results indicate the usefulness of syndecan‐1, Notch‐1, and integrin‐β1 as NSC markers. © 2005 Wiley‐Liss, Inc.
Glucose‐6‐phosphate dehydrogenase and NADPH‐consuming enzymes in the rat olfactory bulb
Authors: Biagiotti Enrica , Ferri Paola , Dringen Ralf , Del Grande Paolo , Ninfali Paolino 
Published: March 2005

AbstractThe resistance to oxidative stress is a multifactorial reaction involving the clustering of transcriptionally regulated genes. Because glucose‐6‐phosphate dehydrogenase (G6PD), the principal enzyme responsible for reducing power, is highly expressed in the olfactory bulb (OB), it is of interest to verify whether other enzymes utilizing NADPH are also highly expressed. The level and localization of G6PD‐ and NADPH‐consuming enzymes, such as NADPH‐cytochrome P450 oxidoreductase (P450R), glutathione reductase (GR), and NADPH‐diaphorase (NADPH‐d), were analyzed in the rat olfactory bulb (OB) by quantitative histochemistry and immunohistochemistry. The highest concentration of G6PD, P450R, and GR was observed in the olfactory nerve layer (ONL), suggesting a correlation in the expression of these enzymes at the gene level. Correlation in staining intensity between G6PD and NADPH‐d activities occurred only in part of the ONL, some glomeruli, and scattered periglomerular cells. This peculiar distribution of NADPH‐d could reflect a spatial patterning of the nose to bulb projections. Taken together, these results indicate that G6PD expression in the ONL could be related to the importance of generating a substantial supply of NADPH to sustain the detoxifying systems represented by GR and P450R reactions and, only in discrete zones, by NADPH‐d activity. © 2005 Wiley‐Liss, Inc.
Regulation of NT‐3 and BDNF levels in guinea pig auditory brain stem nuclei after unilateral cochlear ablation
Authors: Suneja Sanoj K. , Yan Leqin , Potashner Steven J. 
Published: March 2005

AbstractInjury to areas of the central nervous system can alter neurotrophin levels, which may influence postlesion neuronal survival and plasticity. To determine if sensorineural hearing loss induces such changes, we used an enzyme‐linked immunosorbent assay (ELISA) to measure neurotrophin‐3 (NT‐3) and brain‐derived neurotrophic factor (BDNF) levels in adult guinea pig brain stem auditory nuclei 3–60 days after a unilateral cochlear ablation (UCA). After UCA, which destroyed the cochlea and cochlear nerve on one side, NT‐3 levels were usually depressed at 3 days by 22–44% but became elevated transiently at 7 days by 28–124%. BDNF levels were elevated transiently by 50% on the ablated side in the anteroventral (AVCN) and posteroventral (PVCN) cochlear nucleus at 3 days and may have signaled support for the survival of deafferented neurons. Coincident elevation at 3 and 7 days of BDNF or NT‐3 and phosphorylated extracellular signal‐regulated protein kinase 2 (ERK2‐P) suggested a relationship to stimulated signal transduction activity. Elevated neurotrophin levels may have contributed to synaptogenesis in the AVCN and the superior olive and to changes in the synaptic biochemistry in the auditory nuclei after UCA. In contrast, deficiencies or failure to elevate neurotrophin levels within several days of the UCA correlated with upregulation of phosphorylated stress‐activated protein kinase (SAPK‐P), suggesting a relationship with stress‐activated signal transduction and with the sparse degeneration of fibers observed in some of the auditory nuclei after UCA. © 2005 Wiley‐Liss, Inc.
Reduced CSF PLTP activity in Alzheimer's disease and other neurologic diseases; PLTP induces ApoE secretion in primary human astrocytes in vitro
Authors: Vuletic Simona , Peskind Elaine R. , Marcovina Santica M. , Quinn Joseph F. , Cheung Marian C. , Kennedy Hal , Kaye Jeffrey A. , Jin Lee‐Way , Albers John J. 
Published: March 2005

AbstractPhospholipid transfer protein (PLTP) plays a pivotal role in cellular lipid efflux and modulation of lipoprotein metabolism. PLTP is distributed widely in the central nervous system (CNS), is synthesized by glia and neurons, and is active in cerebrospinal fluid (CSF). The aims of this study were to test the hypothesis that patients with Alzheimer's disease (AD) have altered PLTP‐mediated phospholipid transfer activity in CSF, and to examine the potential relationship between PLTP activity and apolipoprotein E (apoE) levels in CSF. We assessed PLTP activity and apoE concentration in CSF of patients with probable AD (n = 50), multiple sclerosis (MS; n = 9), other neurologic diseases (n = 21), and neurologically healthy controls (n = 40). PLTP activity in AD was reduced compared to that in controls (P < 0.001), with approximately half of the AD patients with PLTP activity values below all controls. Patients with MS had lower PLTP activity than AD patients (P < 0.001). PLTP activity was highly correlated with PLTP mass, as estimated by Western blot (r = 0.006; P < 0.01). CSF PLTP activity positively correlated with apoE concentration in AD (R = 0.435; P = 0.002) and controls (R = 0.456; P = 0.003). Anti‐apoE immunoaffinity chromatography and Western blot analyses indicated that some CSF PLTP is associated with apoE‐containing lipoproteins. Exogenous addition of recombinant PLTP to primary human astrocytes significantly increased apoE secretion to the conditioned medium. The findings of reduced PLTP activity in AD CSF, and the observation that PLTP can influence apoE secretion in astrocytes suggest a potential link between alterations in the brain lipid metabolism and AD pathogenesis. © 2005 Wiley‐Liss, Inc.