The Experts below are selected from a list of 273 Experts worldwide ranked by ideXlab platform
Alejandro F. Nicola - One of the best experts on this subject based on the ideXlab platform.
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Progesterone Effects on Neuronal Ultrastructure and Expression of Microtubule-Associated Protein 2 (MAP2) in Rats with Acute Spinal Cord Injury
Cellular and Molecular Neurobiology, 2009Co-Authors: Susana L. González, Juan José López-costa, Florencia Labombarda, Maria Claudia González Deniselle, Rachida Guennoun, Michael Schumacher, Alejandro F. NicolaAbstract:(1) Following acute spinal cord injury, progesterone modulates several molecules essential for motoneuron function, although the morphological substrates for these effects are unknown. (2) The present study analyzed morphological changes in motoneurons distal to the lesion site from rats with or without progesterone treatment. We employed electron microscopy to study changes in nucleus and cytoplasm and immunohistochemistry for the Microtubule-Associated Protein 2 (MAP2) for changes in cytoskeleton. (3) After spinal cord injury, the nucleoplasm appeared more finely dispersed resulting in reduced electron opacity and the nucleus adopted an eccentric position. Changes of perikarya included dissolution of Nissl bodies and dissociation of polyribosomes (chromatolysis). After progesterone treatment for 3 days, the deafferented motoneurons now presented a clumped nucleoplasm, a better-preserved rough endoplasmic reticulum and absence of chromatolysis. Progesterone partially prevented development of nuclear eccentricity. Whereas 50% of injured motoneurons showed nuclear eccentricity, only 16% presented this phenotype after receiving progesterone. Additionally, injured rats showed reduced immunostaining for MAP2 in dendrites, pointing to cytoskeleton abnormalities, whereas progesterone treatment attenuated the injury-induced loss of MAP2. (4) Our data indicated that progesterone maintained in part neuronal ultrastructure, attenuated chromatolysis, and preclude the loss of MAP2, suggesting a protective effect during the early phases of spinal cord injury.
D Higgins - One of the best experts on this subject based on the ideXlab platform.
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Osteogenic Protein-1 and related bone morphogenetic Proteins regulate dendritic growth and the expression of Microtubule-Associated Protein-2 in rat sympathetic neurons
Neuroscience Letters, 1998Co-Authors: Xin Guo, D Rueger, D HigginsAbstract:Osteogenic Protein-1 (OP-1) is expressed in the developing nervous system and it has been found to induce dendritic growth in sympathetic neurons. To further characterize this phenomenon, the effects of OP-1 were compared to those of other members of the bone morphogenetic Protein (BMP) family of growth factors. Recombinant human OP-1, BMP-6, BMP-2 and the Drosophila 60A Protein induced dendritic growth in rat sympathetic neurons in a concentration-dependent manner with EC50-values of 1.8, 1.0, 1.7 and 2.7 ng/ml, respectively. In contrast, BMP-3 and cartilage-derived morphogenetic Protein-2 (CDMP-2) as well as other classes of growth factors were inactive at concentrations up to 50 ng/ml. The dendritic growth induced by OP-1, BMP- 6, BMP-2 and 60A was accompanied by increased expression of microtubule- associated Protein-2 (MAP2) without changes in the expression of the phosphorylated forms of the M and H neurofilament subunits. These results suggest that several members of the BMP family have the capacity to regulate the morphological development of sympathetic neurons and that they may act by induction of specific cytoskeletal Proteins.
Jane A. Alston - One of the best experts on this subject based on the ideXlab platform.
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Cysteine oxidation of tau and Microtubule-Associated Protein-2 by peroxynitrite: Modulation of microtubule assembly kinetics by the thioredoxin reductase system
Journal of Biological Chemistry, 2004Co-Authors: Lisa M. Landino, Tabor E. Skreslet, Jane A. AlstonAbstract:Alterations in the redox status of Proteins have been implicated in the pathology of several neurodegenerative conditions including Alzheimer and Parkinson diseases. We report that peroxynitrite- and hydrogen peroxide-induced disulfides in the neuron-specific Microtubule-Associated Proteins tau and Microtubule-Associated Protein-2 are substrates for the ubiquitous thioredoxin reductase system composed of thioredoxin reductase, human or Escherichia coli thioredoxin, and NADPH. Tau and Microtubule-Associated Protein-2 cysteine oxidation and reduction were quantitated by monitoring the incorporation of 5-iodoacetamidofluorescein, a thiol-specific labeling reagent. Cysteine oxidation of tau and Microtubule-Associated Protein-2 to disulfides altered the ability of the Proteins to promote the assembly of microtubules from purified porcine tubulin. Treatment of tau and Microtubule-Associated Protein-2 with either the thioredoxin reductase system or small molecule reductants fully restores the ability of the MAPs to promote microtubule assembly. Thus changes in the redox state of Microtubule-Associated Proteins may regulate microtubule polymerization in vivo.
Susana L. González - One of the best experts on this subject based on the ideXlab platform.
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Progesterone Effects on Neuronal Ultrastructure and Expression of Microtubule-Associated Protein 2 (MAP2) in Rats with Acute Spinal Cord Injury
Cellular and Molecular Neurobiology, 2009Co-Authors: Susana L. González, Juan José López-costa, Florencia Labombarda, Maria Claudia González Deniselle, Rachida Guennoun, Michael Schumacher, Alejandro F. NicolaAbstract:(1) Following acute spinal cord injury, progesterone modulates several molecules essential for motoneuron function, although the morphological substrates for these effects are unknown. (2) The present study analyzed morphological changes in motoneurons distal to the lesion site from rats with or without progesterone treatment. We employed electron microscopy to study changes in nucleus and cytoplasm and immunohistochemistry for the Microtubule-Associated Protein 2 (MAP2) for changes in cytoskeleton. (3) After spinal cord injury, the nucleoplasm appeared more finely dispersed resulting in reduced electron opacity and the nucleus adopted an eccentric position. Changes of perikarya included dissolution of Nissl bodies and dissociation of polyribosomes (chromatolysis). After progesterone treatment for 3 days, the deafferented motoneurons now presented a clumped nucleoplasm, a better-preserved rough endoplasmic reticulum and absence of chromatolysis. Progesterone partially prevented development of nuclear eccentricity. Whereas 50% of injured motoneurons showed nuclear eccentricity, only 16% presented this phenotype after receiving progesterone. Additionally, injured rats showed reduced immunostaining for MAP2 in dendrites, pointing to cytoskeleton abnormalities, whereas progesterone treatment attenuated the injury-induced loss of MAP2. (4) Our data indicated that progesterone maintained in part neuronal ultrastructure, attenuated chromatolysis, and preclude the loss of MAP2, suggesting a protective effect during the early phases of spinal cord injury.
Lisa M. Landino - One of the best experts on this subject based on the ideXlab platform.
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Redox modulation of tau and Microtubule-Associated Protein-2 by the glutathione/glutaredoxin reductase system.
Biochemical and Biophysical Research Communications, 2004Co-Authors: Lisa M. Landino, Tabor E. Skreslet, Sarah H. Robinson, Diana M. CabralAbstract:Alterations in the redox status of Proteins have been implicated in the pathology of several neurodegenerative diseases including Alzheimer’s and Parkinson’s. We report that peroxynitrite and H2O2-induced disulfides in the porcine brain Microtubule-Associated Proteins tau and Microtubule-Associated Protein-2 are substrates for the glutaredoxin reductase system composed of glutathione reductase, human or Escherichia coli glutaredoxin, reduced glutathione, and NADPH. Oxidation and reduction of cysteines in tau and Microtubule-Associated Protein-2 were quantitated by monitoring the incorporation of 5-iodoacetamido-fluorescein, a thiol-specific labeling reagent. Reduction of disulfide bonds in the Microtubule-Associated Proteins by the glutaredoxin reductase system restored their ability to promote the assembly of microtubules composed of purified porcine tubulin. Thiol-disulfide exchange between oxidized glutathione and the Microtubule-Associated Proteins was detected by monitoring Protein oxidation and was quantitated by measuring reduced glutathione by HPLC.
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Cysteine oxidation of tau and Microtubule-Associated Protein-2 by peroxynitrite: Modulation of microtubule assembly kinetics by the thioredoxin reductase system
Journal of Biological Chemistry, 2004Co-Authors: Lisa M. Landino, Tabor E. Skreslet, Jane A. AlstonAbstract:Alterations in the redox status of Proteins have been implicated in the pathology of several neurodegenerative conditions including Alzheimer and Parkinson diseases. We report that peroxynitrite- and hydrogen peroxide-induced disulfides in the neuron-specific Microtubule-Associated Proteins tau and Microtubule-Associated Protein-2 are substrates for the ubiquitous thioredoxin reductase system composed of thioredoxin reductase, human or Escherichia coli thioredoxin, and NADPH. Tau and Microtubule-Associated Protein-2 cysteine oxidation and reduction were quantitated by monitoring the incorporation of 5-iodoacetamidofluorescein, a thiol-specific labeling reagent. Cysteine oxidation of tau and Microtubule-Associated Protein-2 to disulfides altered the ability of the Proteins to promote the assembly of microtubules from purified porcine tubulin. Treatment of tau and Microtubule-Associated Protein-2 with either the thioredoxin reductase system or small molecule reductants fully restores the ability of the MAPs to promote microtubule assembly. Thus changes in the redox state of Microtubule-Associated Proteins may regulate microtubule polymerization in vivo.