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Ye Xiong - One of the best experts on this subject based on the ideXlab platform.

  • A Small Molecule Spinogenic Compound Enhances Functional Outcome and Dendritic Spine Plasticity in a Rat Model of Traumatic Brain Injury.
    Henry Ford Health System Scholarly Commons, 2019
    Co-Authors: Zhang Yanlu, Simmon Vincent F, Chopp Michael, Rex, Christopher S, Sarraf, Stella T, Zhang Zhenggang, Mahmood Asim, Ye Xiong
    Abstract:

    The tetra (Ethylene Glycol) Derivative of benzothiazole aniline (SPG101) has been shown to improve dendritic spine density and cognitive memory in the triple transgenic mouse model of Alzheimer disease (AD) when administered intraperitoneally. The present study was designed to investigate the therapeutic effects of SPG101 on dendritic spine density and morphology and sensorimotor and cognitive functional recovery in a rat model of traumatic brain injury (TBI) induced by controlled cortical impact (CCI). Young adult male Wistar rats with CCI were randomly divided into the following two groups (n = 7/group): (1) Vehicle, and (2) SPG101. SPG101 (30 mg/kg) dissolved in vehicle (1% dimethyl sulfoxide in phosphate buffered saline) or Vehicle were intraperitoneally administered starting at 1 h post-injury and once daily for the next 34 days. Sensorimotor deficits were assessed using a modified neurological severity score and adhesive removal and foot fault tests. Cognitive function was measured by Morris water maze, novel object recognition (NOR), and three-chamber social recognition tests. The animals were sacrificed 35 days after injury, and their brains were processed for measurement of dendritic spine density and morphology using ballistic dye labeling. Compared with the vehicle treatment, SPG101 treatment initiated 1 h post-injury significantly improved sensorimotor functional recovery (days 7-35, p \u3c 0.0001), spatial learning (days 32-35, p \u3c 0.0001), NOR (days 14 and 35, p \u3c 0.0001), social recognition (days 14 and 35, p \u3c 0.0001). Further, treatment significantly increased dendritic spine density in the injured cortex (p \u3c 0.05), decreased heterogeneous distribution of spine lengths in the injured cortex and hippocampus (p \u3c 0.0001), modifications that are associated with the promotion of spine maturation in these brain regions. In summary, treatment with SPG101 initiated 1 h post-injury and continued for an additional 34 days improves both sensorimotor and cognitive functional recovery, indicating that SPG101 acts as a spinogenic agent and may have potential as a novel treatment of TBI

  • A Small Molecule Spinogenic Compound Enhances Functional Outcome and Dendritic Spine Plasticity in a Rat Model of Traumatic Brain Injury
    Journal of neurotrauma, 2018
    Co-Authors: Yanlu Zhang, Michael Chopp, Christopher S. Rex, Simmon Vincent F, Stella T. Sarraf, Zheng Gang Zhang, Asim Mahmood, Ye Xiong
    Abstract:

    Abstract The tetra (Ethylene Glycol) Derivative of benzothiazole aniline (SPG101) has been shown to improve dendritic spine density and cognitive memory in the triple transgenic mouse model of Alzh...

Tetsushi Taguchi - One of the best experts on this subject based on the ideXlab platform.

  • induced albumin secretion from hepg2 spheroids prepared using poly Ethylene Glycol Derivative with oleyl groups
    Journal of Materials Science: Materials in Medicine, 2011
    Co-Authors: Michiko Ito, Tetsushi Taguchi, Zhi Rao, Miyuki Matsuda
    Abstract:

    We developed a poly(Ethylene Glycol) (PEG) Derivative with oleyl groups, so-called “cell adhesive”, for the promotion of human hepatocellular carcinoma HepG2 cell spheroids. Our approach was based on crosslinking of the cell membrane with a cell adhesive via a hydrophobic interaction. A cell adhesive, PEG Derivative with hydrophobic oleyl groups at both ends was synthesized and characterized. HepG2 spheroids formed when the adhesive was added to cell suspensions. The size of the spheroids increased with time in culture. In addition, Ammonia elimination of HepG2 spheroid with cell adhesive was 3.4 times higher than that without cell adhesive. Furthermore, albumin secretion from HeG2 spheroids grown with the cell adhesive for 7 days was 3.3 times that from HepG2 spheroids grown without cell adhesive. Fluorescence microscopy showed greater albumin staining in spheroids grown with cell adhesive compared with spheroids grown without adhesive. This cell adhesive may be useful not only for single type of cells but also for multi types of cells to form artificial organs. This cell adhesive will be a key material for liver tissue engineering when it will apply to primary hepatocytes.

  • enhanced insulin secretion of physically crosslinked pancreatic β cells by using a poly Ethylene Glycol Derivative with oleyl groups
    Acta Biomaterialia, 2009
    Co-Authors: Michiko Ito, Tetsushi Taguchi
    Abstract:

    Abstract A polymeric crosslinker was developed to promote the formation of cellular spheroids. Our approach was based on the crosslinking of cell membrane using a polymeric crosslinker that worked via hydrophobic interaction. The crosslinker, a poly(Ethylene Glycol) Derivative with oleyl groups as a hydrophobic group at both ends, was synthesized and characterized by gel permeation chromatography and Fourier-transform infrared spectroscopy. Cell culture experiments were then performed to confirm spheroid formation. The rat pancreatic islet β-cell line RIN, which possesses the ability to secrete insulin, was cultured with the crosslinker in a round-bottomed 96-well plate. The formation of a spheroid was achieved when the crosslinker was added to the cell suspension, especially in the absence of serum. The size of the spheroid decreased with time and with increasing crosslinker concentration, and depended on the number of cells plated in each well. The number of cells cultured with crosslinker was almost constant during 7 days and hardly proliferated in crosslinker concentrations of 0–2.5 mg ml −1 , while the number of cells showed a decrease in the 25 mg ml −1 crosslinker concentration. It was shown that the insulin protein secretion in the spheroid cultured with crosslinker for 1 week was enhanced. The cell adhesion protein E-cadherin mRNA expression of the resulting spheroid was also enhanced. These results indicate that the promoted cell function was due to the cell–cell and cell–matrix interactions in the spheroid, suggesting that this polymeric crosslinker was useful for the formation of cell spheroids.

  • The Effect of Serum on the PEG-Based Crosslinker-Induced Spheroid Formation of Pancreatic β-Cell
    The Open Biotechnology Journal, 2008
    Co-Authors: Michiko Ito, Tetsushi Taguchi
    Abstract:

    A polymeric crosslinker poly(Ethylene Glycol) Derivative with dioleyl groups as hydrophobic group at both ends was developed for promoting cellular spheroid formation. Our approach to bridge cells was based on the crosslinking of cell membrane using a crosslinker via the hydrophobic interaction. Using the crosslinker, spheroid formation of pan- creatic � -cell line RIN in a round bottom 96-well plate was evaluated, especially in effect of serum on spheroid formation. In the presence or absence of serum, the size of prepared spheroid was found to decrease with increasing culture time and with increasing crosslinker concentration. However, the medium without serum proved to be a favorable condition for promoting cell aggregation because in this case spheroid with smaller size could be obtained. It was clarified that spheroid formation and insulin secretion of the spheroid prepared by the crosslinker were enhanced, especially in the medium without serum.

  • Synthesis and Evaluation of PEG Derivatives for Crosslinking Cells
    Macromolecular Symposia, 2007
    Co-Authors: Michiko Ito, Tetsuya Tateishi, Tetsushi Taguchi
    Abstract:

    The objective of this study is synthesis, characterization, and evaluation of a novel crosslinker to form spheroids. Our approach was based on the crosslinking of cell membrane using a polymeric crosslinker via hydrophobic interaction. A crosslinker poly(Ethylene Glycol) Derivative with oleyl groups as hydrophobic group at both ends was synthesized, and then characterized with gel permeation chromatography and Fourier-transform infrared spectroscopy. Furthermore, cell culture experiments were performed to confirm spheroid formation. Spheroids were successfully obtained when the crosslinker was added to cell suspension. This polymeric crosslinker was useful in the formation of cell spheroid.

Yuji Inada - One of the best experts on this subject based on the ideXlab platform.

  • stabilization of trypsin by modification with comb shaped copolymers of poly Ethylene Glycol Derivative and maleic anhydride
    Biotechnology Techniques, 1995
    Co-Authors: Misao Hiroto, Motoyuki Yamada, Tomoo Ueno, Tohru Yasukohchi, Ayako Matsushima, Yoh Kodera, Yuji Inada
    Abstract:

    Trypsin from bovine pancreas was coupled with copolymers of poly(Ethylene Glycol) Derivative and maleic anhydride with the molecular weights of 13 kDa and 100 kDa (activated PM13 and PM100). The modified trypsins were more stable towards autolysis and heat- or urea-treatment than nonmodified trypsin. Stabilization of trypsin caused by the chemical modification with activated PMs is discussed in relation to the protein conformation.

  • Stabilization of L-asparaginase modified with comb-shaped poly(Ethylene Glycol) Derivatives, in vivo and in vitro.
    Bioconjugate chemistry, 1994
    Co-Authors: Yoh Kodera, Misao Hiroto, Tohru Yasukohchi, Ayako Matsushima, Taichi Sekine, Yoshihiro Kiriu, Yuji Inada
    Abstract:

    L-Asparaginase from Escherichia coli was coupled with two types of comb-shaped copolymer of poly-(Ethylene Glycol) Derivative and maleic anhydride (activated PM), having molecular weights of 13,000 and 100,000 (activated PM13 and PM100, respectively) with multivalent reaction sites. After single intravenous injections of PM100-asparaginase and nonmodified asparaginase into rats, the enzymic activity of PM100-asparaginase in serum was well retained for at least 11 days, and the serum L-asparagine concentration remained undetectable for 27 days. The half-lives of PM100-asparaginase and nonmodified asparaginase were 50 and 1.5 h, respectively. Stabilization of L-asparaginase toward heat, urea, and acidity was caused by modifying the enzyme with activated PM13 and PM100. Especially, PM100-asparaginase retained high enzymic activity toward heat and urea, compared with PM13-asparaginase. It was suggested that these modifiers with a comb-shaped form and with multivalent reactive sites cover the whole surface of the asparaginase molecule and stabilize its conformation possibly through multiple covalent bindings and through various noncovalent interactions.

Y Inada - One of the best experts on this subject based on the ideXlab platform.

  • Chemical modification of L-asparaginase with comb-shaped copolymer of poly(Ethylene Glycol) Derivative and maleic anhydride.
    Leukemia, 1997
    Co-Authors: T Saito, T Ueno, T Sekine, Y Kodera, M Hiroto, A Matsushima, H Nishimura, Y Inada
    Abstract:

    L-asparaginase from Escherichia coli, an antitumor enzyme, was chemically modified with a comb-shaped copolymer of poly(Ethylene Glycol) Derivative and maleic anhydride (activated PM). The PM-modified asparaginase lost the immunoreactivity with retaining high enzymic activity and also prolonged the clearance time in blood. Intraperitoneal administration of PM-asparaginase markedly increased the mean survival-time of lymphoma L5178Y-bearing mice in comparison with that of unmodified asparaginase. Pretreatment of mice with PM-asparaginase before immunizing with unmodified asparaginase extremely suppressed the anti-asparaginase antibody production.

Chengzhi Cai - One of the best experts on this subject based on the ideXlab platform.