1
|
Hamel E, Royea J, Ongali B, Tong XK. Neurovascular and Cognitive failure in Alzheimer’s Disease: Benefits of Cardiovascular Therapy. Cell Mol Neurobiol 2016; 36:219-32. [DOI: 10.1007/s10571-015-0285-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 10/06/2015] [Indexed: 12/19/2022]
|
2
|
Novel High Content Screen Detects Compounds That Promote Neurite Regeneration from Cochlear Spiral Ganglion Neurons. Sci Rep 2015; 5:15960. [PMID: 26521685 PMCID: PMC4629150 DOI: 10.1038/srep15960] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 10/06/2015] [Indexed: 12/21/2022] Open
Abstract
The bipolar spiral ganglion neurons (SGN) carry sound information from cochlear hair cells to the brain. After noise, antibiotic or toxic insult to the cochlea, damage to SGN and/or hair cells causes hearing impairment. Damage ranges from fiber and synapse degeneration to dysfunction and loss of cells. New interventions to regenerate peripheral nerve fibers could help reestablish transfer of auditory information from surviving or regenerated hair cells or improve results from cochlear implants, but the biochemical mechanisms to target are largely unknown. Presently, no drugs exist that are FDA approved to stimulate the regeneration of SGN nerve fibers. We designed an original phenotypic assay to screen 440 compounds of the NIH Clinical Collection directly on dissociated mouse spiral ganglia. The assay detected one compound, cerivastatin, that increased the length of regenerating neurites. The effect, mimicked by other statins at different optimal concentrations, was blocked by geranylgeraniol. These results demonstrate the utility of screening small compound libraries on mixed cultures of dissociated primary ganglia. The success of this screen narrows down a moderately sized library to a single compound which can be elevated to in-depth in vivo studies, and highlights a potential new molecular pathway for targeting of hearing loss drugs.
Collapse
|
3
|
Cho KJ, Cheon SY, Kim GW. Statins Promote Long-Term Recovery after Ischemic Stroke by Reconnecting Noradrenergic Neuronal Circuitry. Neural Plast 2015; 2015:585783. [PMID: 26448880 PMCID: PMC4581556 DOI: 10.1155/2015/585783] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Revised: 04/06/2015] [Accepted: 04/28/2015] [Indexed: 01/16/2023] Open
Abstract
Inhibitors of HMG-CoA reductase (statins), widely used to lower cholesterol in coronary heart and vascular disease, are effective drugs in reducing the risk of stroke and improving its outcome in the long term. After ischemic stroke, cardiac autonomic dysfunction and psychological problems are common complications related to deficits in the noradrenergic (NA) system. This study investigated the effects of statins on the recovery of NA neuron circuitry and its function after transient focal cerebral ischemia (tFCI). Using the wheat germ agglutinin (WGA) transgene technique combined with the recombinant adenoviral vector system, NA-specific neuronal pathways were labeled, and were identified in the locus coeruleus (LC), where NA neurons originate. NA circuitry in the atorvastatin-treated group recovered faster than in the vehicle-treated group. The damaged NA circuitry was partly reorganized with the gradual recovery of autonomic dysfunction and neurobehavioral deficit. Newly proliferated cells might contribute to reorganizing NA neurons and lead anatomic and functional recovery of NA neurons. Statins may be implicated to play facilitating roles in the recovery of the NA neuron and its function.
Collapse
Affiliation(s)
- Kyoung Joo Cho
- Department of Neurology, College of Medicine, Yonsei University, Seoul 120-752, Republic of Korea
| | - So Young Cheon
- Department of Anesthesiology and Pain, College of Medicine, Yonsei University, Seoul 120-752, Republic of Korea
| | - Gyung Whan Kim
- Department of Neurology, College of Medicine, Yonsei University, Seoul 120-752, Republic of Korea
| |
Collapse
|
4
|
Tušková R, Lipták B, Szomolányi P, Vančová O, Uličná O, Sumbalová Z, Kucharská J, Dubovický M, Trattnig S, Liptaj T, Kašparová S. Neuronal marker recovery after Simvastatin treatment in dementia in the rat brain: in vivo magnetic resonance study. Behav Brain Res 2015; 284:257-64. [PMID: 25698600 DOI: 10.1016/j.bbr.2015.02.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Revised: 02/04/2015] [Accepted: 02/06/2015] [Indexed: 01/16/2023]
Abstract
The aim of study was to search for new biomarkers with a magnetic resonance technique to identify the early stages of dementia, induced by D-galactose, and evaluate Simvastatin therapy. Localized proton magnetic resonance spectroscopy measurements showed a significant decrease in the concentration of N-acetylaspartate+N-acetylaspartylglutamate and myo-inositol in the D-galactose group compared to the control group, and, conversely, an increase of N-acetylaspartate+N-acetylaspartylglutamate in the D-galactose/Simvastatin group. Using a saturation transfer experiment, with phosphorus magnetic resonance spectroscopy, we observed a significant elevation of the forward rate constant of the creatine kinase reaction in the brains of the D-galactose group compared to controls, and subsequently, a significant reduction of this reaction in the D-galactose/Simvastatin group. Spatial learning and memory were evaluated using the modified Morris water maze test. The dynamics of the learning process represented by the learning index revealed a significant reduction in learning in the D-galactose group, but the deficits as a consequence of the D-galactose effects were recovered in the D-galactose/Simvastatin group, in which the learning dynamics resembled those of the control group. By determining the thiobarbituric acid reactive substances and total coenzyme Q9 in plasma, we have shown that long-term administration of D-galactose created conditions for oxidative stress, and that the administration of Simvastatin decreased oxidative stress in plasma. Volumetry analyses from the hippocampal area show a reduction in the segmented area in the D-galactose group, compared with the control group, and an enlarged area in the hippocampus in the d-galactose/Simvastatin group.
Collapse
Affiliation(s)
- Radka Tušková
- Slovak University of Technology in Bratislava, Faculty of Chemical and Food Technology, Institute of Analytical Chemistry, Bratislava, Slovak Republic
| | - Boris Lipták
- Slovak Academy of Sciences, Institute of Experimental Pharmacology & Toxicology, Bratislava, Slovak Republic
| | - Pavol Szomolányi
- High Field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University Vienna, Vienna, Austria
| | - Oľga Vančová
- Comenius University in Bratislava, Medical Faculty, Pharmacobiochemical Laboratory of 3rd Department of Internal Medicine, Bratislava, Slovak Republic
| | - Oľga Uličná
- Comenius University in Bratislava, Medical Faculty, Pharmacobiochemical Laboratory of 3rd Department of Internal Medicine, Bratislava, Slovak Republic
| | - Zuzana Sumbalová
- Comenius University in Bratislava, Medical Faculty, Pharmacobiochemical Laboratory of 3rd Department of Internal Medicine, Bratislava, Slovak Republic
| | - Jarmila Kucharská
- Comenius University in Bratislava, Medical Faculty, Pharmacobiochemical Laboratory of 3rd Department of Internal Medicine, Bratislava, Slovak Republic
| | - Michal Dubovický
- Slovak Academy of Sciences, Institute of Experimental Pharmacology & Toxicology, Bratislava, Slovak Republic
| | - Siegfried Trattnig
- High Field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University Vienna, Vienna, Austria
| | - Tibor Liptaj
- Slovak University of Technology in Bratislava, Faculty of Chemical and Food Technology, Institute of Analytical Chemistry, Bratislava, Slovak Republic
| | - Svatava Kašparová
- Slovak University of Technology in Bratislava, Faculty of Chemical and Food Technology, Institute of Analytical Chemistry, Bratislava, Slovak Republic.
| |
Collapse
|
5
|
Reddy JM, Samuel FG, McConnell JA, Reddy CP, Beck BW, Hynds DL. Non-prenylatable, cytosolic Rac1 alters neurite outgrowth while retaining the ability to be activated. Cell Signal 2014; 27:630-7. [PMID: 25479592 DOI: 10.1016/j.cellsig.2014.11.033] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Revised: 11/26/2014] [Accepted: 11/27/2014] [Indexed: 12/17/2022]
Abstract
Rac1 is an important regulator of axon extension, cell migration and actin reorganization. Like all Rho guanine triphosphatases (GTPases), Rac1 is targeted to the membrane by the addition of a geranylgeranyl moiety, an action thought to result in Rac1 guanosine triphosphate (GTP) binding. However, the role that Rac1 localization plays in its activation (GTP loading) and subsequent activation of effectors is not completely clear. To address this, we developed a non-prenylatable emerald green fluorescent protein (EmGFP)-Rac1 fusion protein (EmGFP-Rac1(C189A)) and assessed how expressing this construct affected neurite outgrowth, Rac1 localization and activation in neuroblastoma cells. Expression of EmGFP-Rac1(C189A) increased localization to the cytosol and induced cell clustering while increasing neurite initiation. EmGFP-Rac1(C189A) expression also increased Rac1 activation in the cytosol, compared to cells expressing wild-type Rac1 (EmGFP-Rac1). These results suggest that activation of Rac1 may not require plasma membrane localization, potentially leading to differential activation of cytosolic signaling pathways that alter cell morphology. Understanding the consequences of differential localization and activation of Rho GTPases, including Rac1, could lead to new therapeutic targets for treating neurological disorders.
Collapse
Affiliation(s)
- Jairus M Reddy
- Texas Woman's University Department of Biology, Denton, TX 76204-5799, United States
| | - Filsy G Samuel
- Center for Research in Neurodegenerative Disease, University of Toronto, Toronto, Canada
| | - Jordan A McConnell
- Texas Woman's University Department of Biology, Denton, TX 76204-5799, United States
| | - Cristina P Reddy
- Texas Woman's University Department of Biology, Denton, TX 76204-5799, United States
| | - Brian W Beck
- Texas Woman's University Department of Biology, Denton, TX 76204-5799, United States
| | - DiAnna L Hynds
- Texas Woman's University Department of Biology, Denton, TX 76204-5799, United States.
| |
Collapse
|