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Biswas K. Microglia mediated neuroinflammation in neurodegenerative diseases: A review on the cell signaling pathways involved in microglial activation. J Neuroimmunol 2023; 383:578180. [PMID: 37672840 DOI: 10.1016/j.jneuroim.2023.578180] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 08/01/2023] [Accepted: 08/23/2023] [Indexed: 09/08/2023]
Abstract
Microglia, the immune sentinels of the central nervous system (CNS), have emerged to be the central players in many neurological and neurodegenerative diseases. Recent studies on large genome databases and omics studies in fact provide support to the idea that microglial cells could be the drivers of these diseases. Microglial cells have the capacity to undergo morphological and phenotypic transformations depending on its microenvironment. From the homeostatic ramified state, they can shift their phenotypes between the two extremes, known as the proinflammatory M1 and anti-inflammatory M2 phenotype, with intermediate transitional states, characterized by different transcriptional signature and release of inflammatory mediators. The temporal regulation of the release of the inflammatory factors are critical for damage control and steering the microglia back towards homeostatic conditions. A dysregulation in these can lead to excessive tissue damage and neuronal death. Therefore, targeting the cell signaling pathways that are the underpinnings of microglial modulations are considered to be an important avenue for treatment of various neurodegenerative diseases. In this review we have discussed various signaling pathways that trigger microglial activation from its ramified state and highlight the mechanisms of microglia-mediated neuroinflammation that are associated with various neurodegenerative diseases. Most of the cellular factors that drive microglia towards a proinflammatory phenotype are components of the immune system signaling pathways and cell proliferation, along with certain ion channels. The anti-inflammatory phenotype is mainly elicited by purinoceptors, metabolic receptors and other receptors that primarily suppress the production proinflammatory mediators.
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Affiliation(s)
- Kaushiki Biswas
- Department of Life Sciences, Presidency University Main campus, 86/1 College Street, Kolkata 700073, India.
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2
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Li S. The β-adrenergic hypothesis of synaptic and microglial impairment in Alzheimer's disease. J Neurochem 2023; 165:289-302. [PMID: 36799441 DOI: 10.1111/jnc.15782] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 02/06/2023] [Accepted: 02/13/2023] [Indexed: 02/18/2023]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disease originating partly from amyloid β protein-induced synaptic failure. As damaging of noradrenergic neurons in the locus coeruleus (LC) occurs at the prodromal stage of AD, activation of adrenergic receptors could serve as the first line of defense against the onset of the disease. Activation of β2 -ARs strengthens long-term potentiation (LTP) and synaptic activity, thus improving learning and memory. Physical stimulation of animals exposed to an enriched environment (EE) leads to the activation of β2 -ARs and prevents synaptic dysfunction. EE also suppresses neuroinflammation, suggesting that β2 -AR agonists may play a neuroprotective role. The β2 -AR agonists used for respiratory diseases have been shown to have an anti-inflammatory effect. Epidemiological studies further support the beneficial effects of β2 -AR agonists on several neurodegenerative diseases. Thus, I propose that β2 -AR agonists may provide therapeutic value in combination with novel treatments for AD.
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Affiliation(s)
- Shaomin Li
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
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Huang R, Meng T, Zhu R, Zhao L, Song D, Yin H, Huang Z, Cheng L, Zhang J. The Integrated Transcriptome Bioinformatics Analysis Identifies Key Genes and Cellular Components for Spinal Cord Injury-Related Neuropathic Pain. Front Bioeng Biotechnol 2020; 8:101. [PMID: 32140464 PMCID: PMC7042182 DOI: 10.3389/fbioe.2020.00101] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 02/03/2020] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Spinal cord injury (SCI) is one of the most devastating diseases with a high incidence rate around the world. SCI-related neuropathic pain (NeP) is a common complication, whereas its pathomechanism is still unclear. The purpose of this study is to identify key genes and cellular components for SCI-related NeP by an integrated transcriptome bioinformatics analysis. METHODS The gene expression profile of 25 peripheral blood samples from chronic phase SCI patients (E-GEOD-69901) and 337 normal peripheral blood samples were downloaded from ArrayExpress and Genotype-Tissue Expression Portal (GTEx), respectively. A total of 3,368 normal peripheral blood mononuclear cells (PBMC) were download from Sequence Read Archive (SRA713577). Non-parametric tests were used to evaluate the association between all of differential expression genes (DEGs) and SCI-related NeP. CellPhoneDB algorithm was performed to identify the ligand-receptor interactions and their cellular localization among single PBMCs. Transcription factor (TF) enrichment analysis and Gene Set Variation Analysis (GSVA) were used to identify the potential upstream regulatory TFs and downstream signaling pathways, respectively. Co-expression analysis among significantly enriched TFs, key cellular communication genes and differentially expressed signaling pathways were performed to identify key genes and cellular components for SCI-related NeP. RESULTS A total of 2,314 genes were identified as DEGs between the experimental and the control group. Five proteins (ADRB2, LGALS9, PECAM1, HAVCR2, LRP1) were identified in the overlap of proteins in the significant ligand-receptor interactions of PBMCs and protein-protein interaction (PPI) network based on the DEGs. Only HAVCR2 was significantly associated with NeP (P = 0.005). Besides, the co-expression analysis revealed that TF YY1 had significantly co-expression pattern with cellular communication receptor HAVCR2 (R = -0.54, P < 0.001) in NK cells while HAVCR2 was also co-expressed with mTOR signaling pathway (R = 0.57, P < 0.001). The results of RT-qPCR and external dataset validation supported the signaling axis with the most significant co-expression patterns. CONCLUSION In peripheral blood of chronic SCI, HAVCR2 might act as a key receptor on the surface of NK cells and interact with ligand LGALS9 secreted by CD14+ monocytes, inhibiting NK cells through mTOR signaling pathway and ultimately predicting the occurrence of SCI-related NeP. This hypothetical signaling axis may provide prognostic biomarkers and therapeutic targets for SCI-related NeP.
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Affiliation(s)
- Runzhi Huang
- Division of Spine, Department of Orthopedics, Tongji Hospital Affiliated to Tongji University School of Medicine, Shanghai, China
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Orthopaedic Department of Tongji Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Tong Meng
- Division of Spine, Department of Orthopedics, Tongji Hospital Affiliated to Tongji University School of Medicine, Shanghai, China
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Orthopaedic Department of Tongji Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Rui Zhu
- Division of Spine, Department of Orthopedics, Tongji Hospital Affiliated to Tongji University School of Medicine, Shanghai, China
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Orthopaedic Department of Tongji Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Lijuan Zhao
- Division of Spine, Department of Orthopedics, Tongji Hospital Affiliated to Tongji University School of Medicine, Shanghai, China
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Orthopaedic Department of Tongji Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Dianwen Song
- Department of Orthopedics, Shanghai General Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Huabin Yin
- Department of Orthopedics, Shanghai General Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Zongqiang Huang
- Department of Orthopedics, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Liming Cheng
- Division of Spine, Department of Orthopedics, Tongji Hospital Affiliated to Tongji University School of Medicine, Shanghai, China
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Orthopaedic Department of Tongji Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Jie Zhang
- Division of Spine, Department of Orthopedics, Tongji Hospital Affiliated to Tongji University School of Medicine, Shanghai, China
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Orthopaedic Department of Tongji Hospital, School of Medicine, Tongji University, Shanghai, China
- Department of Prevention, Tongji University School of Medicine, Tongji University, Shanghai, China
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4
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Zeman RJ, Wen X, Moorthy CR, Etlinger JD. Therapeutic target for external beam x-irradiation in experimental spinal cord injury. J Neurosurg Spine 2020; 32:649-656. [PMID: 31899880 DOI: 10.3171/2019.11.spine19305] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 11/05/2019] [Indexed: 11/06/2022]
Abstract
OBJECTIVE X-irradiation has been shown to be beneficial to recovery from spinal cord injury (SCI); however, the optimal therapeutic target has not been defined. Experiments were designed to determine the optimal target volume within the injured spinal cord for improving functional recovery and sparing tissue with stereotactic x-irradiation. METHODS SCI was produced in rats at the T10 level. A 20-Gy dose of radiation was delivered with a single, 4-mm-diameter, circular radiation beam centered either on the injury epicenter or 4 or 8 mm caudal or rostral to the injury epicenter. Locomotor function was determined for 6 weeks with the Basso, Beattie, and Bresnahan locomotor scale and tissue sparing by histological analysis of transverse sections along the spinal cords. RESULTS X-irradiation of spinal cord segments at 4 mm, but not 8 mm, caudal or rostral to the contusion epicenter resulted in increases in locomotor recovery. Consistently, significant tissue sparing also occurred with x-irradiation centered at those sites, although irradiation centered 4 mm rostral to the epicenter led to tissue sparing along the greatest length of the spinal cord. Interestingly, regression analysis of these variables demonstrated that the quantitative relationship between the amount of tissue spared and the improvement in locomotion recovery was greatest in a region several millimeters rostral to the injury epicenter. CONCLUSIONS These results indicate that x-irradiation in a region rostral to the injury epicenter is optimal for recovery from SCI. This minimal target should be attractive for therapeutic application since it allows a greatly reduced target volume so that uninjured tissue is not needlessly irradiated.
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Affiliation(s)
| | | | - Chitti R Moorthy
- 2Radiation Medicine, New York Medical College, Valhalla, New York
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5
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Lemmens S, Nelissen S, Dooley D, Geurts N, Peters EMJ, Hendrix S. Stress Pathway Modulation Is Detrimental or Ineffective for Functional Recovery after Spinal Cord Injury in Mice. J Neurotrauma 2019; 37:564-571. [PMID: 31210094 DOI: 10.1089/neu.2018.6211] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
A mounting body of evidence suggests that stress plays a major role in the injury progression after spinal cord injury (SCI). Injury activates the stress systems; this in turn may augment the generation of pro-inflammatory cytokines, stimulate pro-inflammatory immune cells, and alter the balance between the pro- and anti-inflammatory immune response. As a result, it is suggested that stress pathways may augment neuronal damage and loss after SCI. Considering these potential detrimental effects of stress after SCI, we hypothesized that inhibition of stress pathways immediately after SCI may offer protection from damage and improve recovery. To investigate the relevance of stress responses in SCI recovery, we investigated the effects of blocking three well-studied stress response axes in a mouse model of SCI. Propranolol, RU-486, and CP-99994 were administered to inhibit the sympathetic axis, the hypothalamus-pituitary-adrenal axis, and the neuropeptide axis, respectively. Surprisingly, assessing functional recovery by the Basso Mouse Scale revealed that RU-486 and CP-99994 did not affect functional outcome, indicating that these pathways are dispensable for neuroprotection or repair after SCI. Moreover, the beta-blocker propranolol worsened functional outcome in the mouse SCI model. In conclusion, immediate inhibition of three major stress axes has no beneficial effects on functional recovery after SCI in mice. These results suggest that injury-induced stress responses do not interfere with the healing process and hence, pharmacological targeting of stress responses is not a recommended treatment option for SCI. These findings are of great importance for other researchers to avoid unnecessary and potentially futile animal experiments.
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Affiliation(s)
- Stefanie Lemmens
- Department of Morphology, Biomedical Research Institute, Hasselt University, Diepenbeek, Belgium
| | - Sofie Nelissen
- Department of Morphology, Biomedical Research Institute, Hasselt University, Diepenbeek, Belgium
| | - Dearbhaile Dooley
- Health Science Centre, School of Medicine, University College Dublin, Belfield, Dublin, Ireland
| | - Nathalie Geurts
- Department of Morphology, Biomedical Research Institute, Hasselt University, Diepenbeek, Belgium
| | - Eva Milena Johanne Peters
- Psychoneuroimmunology Laboratory, Department of Psychosomatic Medicine, Justus Liebig University and Charité Berlin, Germany
| | - Sven Hendrix
- Department of Morphology, Biomedical Research Institute, Hasselt University, Diepenbeek, Belgium
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6
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Scholpa NE, Williams H, Wang W, Corum D, Narang A, Tomlinson S, Sullivan PG, Rabchevsky AG, Schnellmann RG. Pharmacological Stimulation of Mitochondrial Biogenesis Using the Food and Drug Administration-Approved β 2-Adrenoreceptor Agonist Formoterol for the Treatment of Spinal Cord Injury. J Neurotrauma 2018; 36:962-972. [PMID: 30280980 DOI: 10.1089/neu.2018.5669] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
A hallmark of the progressive cascade of damage referred to as secondary spinal cord injury (SCI) is vascular disruption resulting in decreased oxygen delivery and loss of mitochondria homeostasis. While therapeutics targeting restoration of single facets of mitochondrial function have proven largely ineffective clinically post-SCI, comprehensively addressing mitochondrial function via pharmacological stimulation of mitochondrial biogenesis (MB) is an underexplored strategy. This study examined the effects of formoterol, a mitochondrial biogenic Food and Drug Administration-approved selective and potent β2-adrenoreceptor (ADRB2) agonist, on recovery from SCI in mice. Female C57BL/6 mice underwent moderate SCI using a force-controlled impactor-induced contusion model, followed by daily formoterol intraperitoneal administration (0.1 mg/kg) beginning 1 h post-SCI. The SCI resulted in decreased mitochondrial protein expression, including PGC-1α, in the injury and peri-injury sites as early as 3 days post-injury. Formoterol treatment attenuated this decrease in PGC-1α, indicating enhanced MB, and restored downstream mitochondrial protein expression to that of controls by 15 days. Formoterol-treated mice also exhibited less histological damage than vehicle-treated mice 3 days after injury-namely, decreased lesion volume and increased white and gray matter sparing in regions rostral and caudal to the injury epicenter. Importantly, locomotor capability of formoterol-treated mice was greater than vehicle-treated mice by 7 days, reaching a Basso Mouse Scale score two points greater than that of vehicle-treated SCI mice by 15 days. Interestingly, similar locomotor restoration was observed when initiation of treatment was delayed until 8 h post-injury. These data provide evidence of ADRB2-mediated MB as a therapeutic approach for the management of SCI.
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Affiliation(s)
- Natalie E Scholpa
- 1 Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson, Arizona.,2 Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina
| | - Hannah Williams
- 3 Department of Physiology, Spinal Cord and Brain Injury Research Center, University of Kentucky Medical Center, Lexington, Kentucky
| | - Wenxue Wang
- 4 Neuroscience Institute, Medical University of South Carolina, Charleston, South Carolina.,5 Ralph H. Johnsons Veteran Affairs Medical Center, Charleston, South Carolina
| | - Daniel Corum
- 2 Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina
| | - Aarti Narang
- 4 Neuroscience Institute, Medical University of South Carolina, Charleston, South Carolina.,5 Ralph H. Johnsons Veteran Affairs Medical Center, Charleston, South Carolina
| | - Stephen Tomlinson
- 4 Neuroscience Institute, Medical University of South Carolina, Charleston, South Carolina.,5 Ralph H. Johnsons Veteran Affairs Medical Center, Charleston, South Carolina.,6 Department of Microbiology and Immunology, Medical University of South Carolina, Charleston, South Carolina
| | - Patrick G Sullivan
- 7 Department of Neuroscience, Spinal Cord and Brain Injury Research Center, University of Kentucky Medical Center, Lexington, Kentucky
| | - Alexander G Rabchevsky
- 3 Department of Physiology, Spinal Cord and Brain Injury Research Center, University of Kentucky Medical Center, Lexington, Kentucky
| | - Rick G Schnellmann
- 1 Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson, Arizona.,8 Southern Arizona VA Health Care System, Tucson, Arizona.,9 Southwest Environmental Health Science Center, University of Arizona, Tucson, Arizona.,10 Center for Innovation in Brain Science, University of Arizona, Tucson, Arizona
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7
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Ormond DR, Shannon C, Oppenheim J, Zeman R, Das K, Murali R, Jhanwar-Uniyal M. Stem cell therapy and curcumin synergistically enhance recovery from spinal cord injury. PLoS One 2014; 9:e88916. [PMID: 24558450 PMCID: PMC3928327 DOI: 10.1371/journal.pone.0088916] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Accepted: 01/13/2014] [Indexed: 01/11/2023] Open
Abstract
Acute traumatic spinal cord injury (SCI) is marked by the enhanced production of local cytokines and pro-inflammatory substances that induce gliosis and prevent reinnervation. The transplantation of stem cells is a promising treatment strategy for SCI. In order to facilitate functional recovery, we employed stem cell therapy alone or in combination with curcumin, a naturally-occurring anti-inflammatory component of turmeric (Curcuma longa), which potently inhibits NF-κB. Spinal cord contusion following laminectomy (T9–10) was performed using a weight drop apparatus (10 g over a 12.5 or 25 mm distance, representing moderate or severe SCI, respectively) in Sprague-Dawley rats. Neural stem cells (NSC) were isolated from subventricular zone (SVZ) and transplanted at the site of injury with or without curcumin treatment. Functional recovery was assessed by BBB score and body weight gain measured up to 6 weeks following SCI. At the conclusion of the study, the mass of soleus muscle was correlated with BBB score and body weight. Stem cell therapy improved recovery from moderate SCI, however, it had a limited effect on recovery after severe SCI. Curcumin stimulated NSC proliferation in vitro, and in combination with stem cell therapy, induced profound recovery from severe SCI as evidenced by improved functional locomotor recovery, increased body weight, and soleus muscle mass. These findings demonstrate that curcumin in conjunction with stem cell therapy synergistically improves recovery from severe SCI. Furthermore, our results indicate that the effect of curcumin extends beyond its known anti-inflammatory properties to the regulation of stem cell proliferation.
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Affiliation(s)
- D. Ryan Ormond
- Department of Neurosurgery, New York Medical College, Valhalla, New York, United States of America
| | - Craig Shannon
- Department of Neurosurgery, New York Medical College, Valhalla, New York, United States of America
| | - Julius Oppenheim
- Department of Neurosurgery, New York Medical College, Valhalla, New York, United States of America
| | - Richard Zeman
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, New York, United States of America
| | - Kaushik Das
- Department of Neurosurgery, New York Medical College, Valhalla, New York, United States of America
| | - Raj Murali
- Department of Neurosurgery, New York Medical College, Valhalla, New York, United States of America
| | - Meena Jhanwar-Uniyal
- Department of Neurosurgery, New York Medical College, Valhalla, New York, United States of America
- * E-mail:
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8
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Potential benefits of therapeutic use of β2-adrenergic receptor agonists in neuroprotection and Parkinsonμs disease. J Immunol Res 2014; 2014:103780. [PMID: 24741572 PMCID: PMC3987873 DOI: 10.1155/2014/103780] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2013] [Revised: 12/03/2013] [Accepted: 12/04/2013] [Indexed: 11/30/2022] Open
Abstract
The β2-adrenergic receptor (β2AR) is a seven-transmembrane (7TM) G-protein coupled receptor that is expressed on cells of the pulmonary, cardiac, skeletal muscle, and immune systems. Previous work has shown that stimulation of this receptor on immune cells has profound effects on the regulatory activity of both adaptive and innate immune cells. This review examines the functional dichotomy associated with stimulation of β2AR and microglial cells. As well, recent studies targeting these receptors with long-acting agonists are considered with respect to their therapeutic potential in management of Parkinsonμs disease.
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Dose-effects of aorta-infused clenbuterol on spinal cord ischemia-reperfusion injury in rabbits. PLoS One 2013; 8:e84095. [PMID: 24391890 PMCID: PMC3877193 DOI: 10.1371/journal.pone.0084095] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Accepted: 11/11/2013] [Indexed: 01/17/2023] Open
Abstract
Background The β2 adrenergic receptor (β2AR) plays an important role in ischemia-reperfusion (I/R) injury in various organs. Recently, a selective β2AR agonist clenbuterol was suggested to protect against cerebral I/R injury. This study was designed to investigate changes of β2ARs after spinal cord I/R injury and dose-effects of aorta-infused clenbuterol on spinal cord I/R injury in rabbits. Methods Spinal cord ischemia was induced in New Zealand white rabbits by infrarenal abdominal aortic occlusion with a balloon catheter for 30 minutes except the sham group. During occlusion, nothing (I/R group), normal saline (NS group) or clenbuterol at different doses of 0.005, 0.01, 0.05, 0.1, 0.5, or 1 mg/kg (C0.005, C0.01, C0.05, C0.1, C0.5, and C1 groups) was infused into the occluded aortic segments. The hemodynamic data, blood glucose and serum electrolytes were measured during experimental period. Neurological function was assessed according to the modified Tarlov scales until 48 hours after reperfusion. After that, the lumbar spinal cord was harvested for β2AR immunohistochemistry and histopathologic evaluation in the anterior horns. Results The β2AR expression in the anterior horns of the spinal cord was significantly higher in the I/R group than in the sham group. Tarlov scores and the number of viable α-motor neurons were higher in C0.01-C0.5 groups than in the NS group, C0.005 and C1 groups and were highest in the C0.1 group. Hypotension and hyperglycemia were found in the C1 group. Conclusion β2ARs in the anterior horn were upregulated after spinal cord I/R injury. Aortic-infused clenbuterol (0.01–0.5 mg/kg) can attenuate spinal cord I/R injury dose-dependently during the ischemic period. The Optimal dosage was 0.1 mg/kg. Activation of β2AR could be a new therapeutic strategy for the treatment of spinal cord I/R injury.
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Brown A, Nabel A, Oh W, Etlinger JD, Zeman RJ. Perfusion imaging of spinal cord contusion: injury-induced blockade and partial reversal by β2-agonist treatment in rats. J Neurosurg Spine 2013; 20:164-71. [PMID: 24313676 DOI: 10.3171/2013.10.spine13113] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Traumatic injury to the spinal cord results in considerable delayed tissue loss. The authors investigated the extent to which ischemia occurs following contusion-induced spinal cord injury and whether ischemia exacerbates tissue damage that leads to the loss of locomotor function. They also determined if ischemia is reversed with β2-adrenoceptor agonist treatment, which has been established to be neuroprotective following contusion injury. METHODS The extent and role of circulation loss in spinal cord injury was determined in an established experimental model of contusion injury. The spinal cord dura mater of Wistar rats was exposed by performing a laminectomy at T-8 to T-11. Laser Doppler perfusion imaging was then used to measure microcirculation in the exposed spinal cord. After imaging, a moderately severe contusion injury was produced using a weight-drop device unto the exposed dura at T-10. Perfusion imaging was again performed, scans were quantitated, and integrated intensities were compared. RESULTS Postinjury imaging revealed an 18%-27% reduction in perfusion in regions rostral and caudal to the injury site, and a 68% reduction was observed at the contusion epicenter. These perfusion losses persisted for at least 48 hours. At 24 hours after injury, some rats were intraperitoneally injected with 2 mg/kg of the β2-adrenoceptor agonist clenbuterol, which has been shown to promote the partial recovery of locomotor function and spare spinal cord tissue when administered within 2 days after contusion injury. Clenbuterol injection caused a gradual increase in perfusion, which was detectable at 30 minutes postinjection and continued over time, resulting in an 127% overall increase in perfusion at the epicenter 24 hours after treatment. CONCLUSIONS These results suggest that the occurrence of chronic perfusion loss after contusion contributes to delayed damage and tissue loss. In contrast, β2-adrenoceptor agonist treatment may exert neuroprotection by restoring perfusion, thereby preventing ischemic neurodegeneration. The ability of laser Doppler imaging to measure the loss of perfusion and its restoration upon treatment suggests that it may have clinical utility in the assessment and treatment of spinal cord injury.
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Affiliation(s)
- Abraham Brown
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla; and
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11
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Lee BY, Al-Waili N, Butler G. The effect of adrenergic β(2) receptor agonist on paraplegia following clamping of abdominal aorta. Arch Med Sci 2011; 7:597-603. [PMID: 22291794 PMCID: PMC3258778 DOI: 10.5114/aoms.2011.24128] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2010] [Revised: 11/17/2010] [Accepted: 12/28/2010] [Indexed: 11/17/2022] Open
Abstract
INTRODUCTION Surgical repair of an aortic aneurysm might be complicated by spinal cord injury and paraplegia. Since β-adrenoreceptor agonists showed neuroprotective effects, the study was designed to investigate the effect of clenbuterol on post-aortic clamping paraplegia and to identify if there is hyperemia associated with paraplegia. MATERIAL AND METHODS Thirty rabbits were divided into two groups: 15 control and 15 experimental (given clenbuterol 9 mg in drinking water 24 h prior to surgery). All the animals were subjected to laparotomy whereas the abdominal aorta was identified. Using a vascular clamp, the abdominal aorta was clamped just distal to the renal arteries. Abdominal aortic blood flow was recorded with a transonic flow meter. The neurological assessment was made according to Tarlov's Neurological Scale upon recovering from anesthesia. Anal sphincter tonus and bladder sphincter function were also checked. RESULTS Four rabbits (2 control and 2 experimental) developed complete paraplegia within 30 min of cross-clamping of the aorta. Of the 13 controls, 77% developed paraplegia, and of the 13 experimental rabbits administered clenbuterol 24 h prior to surgery with 22 min of aortic cross-clamping, 38% developed paraplegia The rabbits which did not develop paraplegia had a minimal increase in aortic blood flow, whereas the rabbits which developed paraplegia had a significant increase in aortic blood flow measurements after aortic decamping. CONCLUSIONS Post-aortic clamping paraplegia is associated with hyperemia and clenbuterol has a significant neuroprotective effect, obviously by preventing an increase in aortic blood flow following unclamping.
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Affiliation(s)
- Bok Y. Lee
- Department of Surgery, New York Medical College, USA
| | - Noori Al-Waili
- Life Support Technology Group, Mount Vernon, New York, USA
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12
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Qian L, Wu HM, Chen SH, Zhang D, Ali SF, Peterson L, Wilson B, Lu RB, Hong JS, Flood PM. β2-adrenergic receptor activation prevents rodent dopaminergic neurotoxicity by inhibiting microglia via a novel signaling pathway. THE JOURNAL OF IMMUNOLOGY 2011; 186:4443-54. [PMID: 21335487 DOI: 10.4049/jimmunol.1002449] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The role of the β2 adrenergic receptor (β2AR) in the regulation of chronic neurodegenerative inflammation within the CNS is poorly understood. The purpose of this study was to determine neuroprotective effects of long-acting β2AR agonists such as salmeterol in rodent models of Parkinson's disease. Results showed salmeterol exerted potent neuroprotection against both LPS and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine/1-methyl-4-phenylpyridinium-induced dopaminergic neurotoxicity both in primary neuron-glia cultures (at subnanomolar concentrations) and in mice (1-10 μg/kg/day doses). Further studies demonstrated that salmeterol-mediated neuroprotection is not a direct effect on neurons; instead, it is mediated through the inhibition of LPS-induced microglial activation. Salmeterol significantly inhibited LPS-induced production of microglial proinflammatory neurotoxic mediators, such as TNF-α, superoxide, and NO, as well as the inhibition of TAK1-mediated phosphorylation of MAPK and p65 NF-κB. The anti-inflammatory effects of salmeterol required β2AR expression in microglia but were not mediated through the conventional G protein-coupled receptor/cAMP pathway. Rather, salmeterol failed to induce microglial cAMP production, could not be reversed by either protein kinase A inhibitors or an exchange protein directly activated by cAMP agonist, and was dependent on β-arrestin2 expression. Taken together, our results demonstrate that administration of extremely low doses of salmeterol exhibit potent neuroprotective effects by inhibiting microglial cell activation through a β2AR/β-arrestin2-dependent but cAMP/protein kinase A-independent pathway.
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Affiliation(s)
- Li Qian
- North Carolina Oral Health Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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13
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Partial functional recovery after complete spinal cord transection by combined chondroitinase and clenbuterol treatment. Pflugers Arch 2010; 460:657-66. [DOI: 10.1007/s00424-010-0852-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2010] [Revised: 05/21/2010] [Accepted: 06/02/2010] [Indexed: 01/15/2023]
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14
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Zeman RJ, Bauman WA, Wen X, Ouyang N, Etlinger JD, Cardozo CP. Improved functional recovery with oxandrolone after spinal cord injury in rats. Neuroreport 2009; 20:864-8. [PMID: 19424096 DOI: 10.1097/wnr.0b013e32832c5cc2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
At present, only the corticosteroid, methylprednisolone, is used for acute spinal cord injury to improve function. However, improvements are modest, and are associated with myopathy and immunosuppression so that alternative treatments are needed. Oxandrolone is an androgenic steroid with potential neuroprotective properties that is used to prevent muscle loss and is not immunosuppressive. Oxandrolone increased locomotor recovery concomitant with reduced loss of cord tissue in a standard weight drop model of spinal cord contusion injury indicating oxandrolone as a possible alternative to methylprednisolone. Oxandrolone also increased axonal sprouting within the ventral horns distal to the injury consistent with formation of relay circuits mediating locomotor recovery.
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Affiliation(s)
- Richard J Zeman
- Center of Excellence for the Medical Consequences of Spinal Cord Injury, James J. Peters VA Medical Center, Bronx, NY 10468, USA
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15
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Zeman RJ, Wen X, Ouyang N, Rocchio R, Shih L, Alfieri A, Moorthy C, Etlinger JD. STEREOTACTIC RADIOSURGERY IMPROVES LOCOMOTOR RECOVERY AFTER SPINAL CORD INJURY IN RATS. Neurosurgery 2008; 63:981-7; discussion 987-8. [DOI: 10.1227/01.neu.0000330404.37092.3e] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Abstract
OBJECTIVE
Currently, because of the precision of stereotactic radiosurgery, radiation can now be delivered by techniques that shape the radiation beam to the tissue target for a variety of clinical applications. This avoids unnecessary and potentially damaging irradiation of surrounding tissues inherent in conventional irradiation, so that irradiation of the minimum volume of tissue necessary for optimal therapeutic benefit can be achieved. Although conventional x-irradiation has been shown to improve recovery from spinal cord injury in animals, the efficacy of targeted irradiation of the injured spinal cord has not been demonstrated previously. The purpose of these studies was to determine whether stereotactic x-irradiation of the injured spinal cord can enhance locomotor function and spare spinal cord tissue after contusion injury in a standard experimental model of spinal cord injury.
METHODS
Contusion injury was produced in rats at the level of T10 with a weight-drop device, and doses of x-irradiation were delivered 2 hours after injury via a Novalis, 6-MeV linear accelerator shaped beam radiosurgery system (BrainLAB USA, Westchester, IL) in 4 sequential fractions, with beam angles 60 to 70 degrees apart, at a rate of 6.4 Gy/minute. The target volume was a 4 × 15-mm cylinder along the axis of the spinal cord, with the isocenter positioned at the contusion epicenter. Locomotor function was determined for 6 weeks after injury with the 21-point Basso, Beattie, and Bresnahan (BBB) locomotor scale and tissue sparing in histological sections of the spinal cord.
RESULTS
Locomotor function recovered progressively during the 6-week postinjury observation period. BBB scores were significantly greater in the 10-Gy x-irradiated group compared with controls (9.4 versus 7.3; P < 0.05), indicating hind limb weight support or dorsal stepping in contrast to hind limb joint mobility without weight bearing. Doses in the range of 2 to 10 Gy increased BBB scores progressively, whereas greater doses of 15 to 25 Gy were associated with lower BBB scores. The extent of locomotor recovery after treatment with x-irradiation correlated with measurements of spared spinal cord tissue at the contusion epicenter.
CONCLUSION
These results suggest a beneficial role for stereotactic radiosurgery in a rat model of acute spinal cord contusion injury and raise hopes for human treatment strategies. Additional animal studies are needed to further define potential benefits.
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Affiliation(s)
- Richard J. Zeman
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, New York, and MotoGen, Inc., Mount Kisco, New York
| | - Xialing Wen
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, New York
| | - Nengtai Ouyang
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, New York
| | - Ronald Rocchio
- Department of Radiation Medicine, New York Medical College, Valhalla, New York
| | - Lynn Shih
- Department of Radiation Medicine, New York Medical College, Valhalla, New York
| | - Alan Alfieri
- Department of Radiation Medicine, New York Medical College, Valhalla, New York
| | - Chitti Moorthy
- Department of Radiation Medicine, New York Medical College, Valhalla, New York
| | - Joseph D. Etlinger
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, New York, and MotoGen, Inc., Mount Kisco, New York
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16
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Hillard VH, Peng H, Das K, Murali R, Moorthy CR, Etlinger JD, Zeman RJ. Inhibition of x-irradiation–enhanced locomotor recovery after spinal cord injury by hyperbaric oxygen or the antioxidant nitroxide tempol. J Neurosurg Spine 2007; 6:337-43. [PMID: 17436923 DOI: 10.3171/spi.2007.6.4.9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Object
Hyperbaric oxygen (HBO), the nitroxide antioxidant tempol, and x-irradiation have been used to promote locomotor recovery in experimental models of spinal cord injury. The authors used x-irradiation of the injury site together with either HBO or tempol to determine whether combined therapy offers greater benefit to rats.
Methods
Contusion injury was produced with a weight-drop device in rats at the T-10 level, and recovery was determined using the 21-point Basso-Beattie-Bresnahan (BBB) locomotor scale. Locomotor function recovered progressively during the 6-week postinjury observation period and was significantly greater after x-irradiation (20 Gy) of the injury site or treatment with tempol (275 mg/kg intraperitoneally) than in untreated rats (final BBB Scores 10.6 [x-irradiation treated] and 9.1 [tempol treated] compared with 6.4 [untreated], p < 0.05). Recovery was not significantly improved by HBO (2 atm for 1 hour [BBB Score 8.2, p > 0.05]). Interestingly, the improved recovery of locomotor function after x-irradiation, in contrast with antiproliferative radiotherapy for neoplasia, was inhibited when used together with either HBO or tempol (BBB Scores 8.2 and 8.3, respectively). The ability of tempol to block enhanced locomotor recovery by x-irradiation was accompanied by prevention of alopecia at the irradiation site. The extent of locomotor recovery following treatment with tempol, HBO, and x-irradiation correlated with measurements of spared spinal cord tissue at the contusion epicenter.
Conclusions
These results suggest that these treatments, when used alone, can activate neuroprotective mechanisms but, in combination, may result in neurotoxicity.
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Affiliation(s)
- Virany H Hillard
- Department of Neurosurgery, New York Medical College, New York,. USA.
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