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Schepers M, Hendrix S, Mussen F, van Breedam E, Ponsaerts P, Lemmens S, Hellings N, Ricciarelli R, Fedele E, Bruno O, Brullo C, Prickaerts J, Van Broeckhoven J, Vanmierlo T. Amelioration of functional and histopathological consequences after spinal cord injury through phosphodiesterase 4D (PDE4D) inhibition. Neurotherapeutics 2024; 21:e00372. [PMID: 38760316 PMCID: PMC11284540 DOI: 10.1016/j.neurot.2024.e00372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 04/15/2024] [Accepted: 05/01/2024] [Indexed: 05/19/2024] Open
Abstract
Spinal cord injury (SCI) is a life-changing event that severely impacts the patient's quality of life. Modulating neuroinflammation, which exacerbates the primary injury, and stimulating neuro-regenerative repair mechanisms are key strategies to improve functional recovery. Cyclic adenosine monophosphate (cAMP) is a second messenger crucially involved in both processes. Following SCI, intracellular levels of cAMP are known to decrease over time. Therefore, preventing cAMP degradation represents a promising strategy to suppress inflammation while stimulating regeneration. Intracellular cAMP levels are controlled by its hydrolyzing enzymes phosphodiesterases (PDEs). The PDE4 family is most abundantly expressed in the central nervous system (CNS) and its inhibition has been shown to be therapeutically relevant for managing SCI pathology. Unfortunately, the use of full PDE4 inhibitors at therapeutic doses is associated with severe emetic side effects, hampering their translation toward clinical applications. Therefore, in this study, we evaluated the effect of inhibiting specific PDE4 subtypes (PDE4B and PDE4D) on inflammatory and regenerative processes following SCI, as inhibitors selective for these subtypes have been demonstrated to be well-tolerated. We reveal that administration of the PDE4D inhibitor Gebr32a, even when starting 2 dpi, but not the PDE4B inhibitor A33, improved functional as well as histopathological outcomes after SCI, comparable to results obtained with the full PDE4 inhibitor roflumilast. Furthermore, using a luminescent human iPSC-derived neurospheroid model, we show that PDE4D inhibition stabilizes neural viability by preventing apoptosis and stimulating neuronal differentiation. These findings strongly suggest that specific PDE4D inhibition offers a novel therapeutic approach for SCI.
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Affiliation(s)
- Melissa Schepers
- Department of Neuroscience, Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, 3500 Hasselt, Belgium; Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, 6229ER Maastricht, the Netherlands; University MS Centre (UMSC) Hasselt - Pelt, Belgium
| | - Sven Hendrix
- Institute for Translational Medicine, Medical School Hamburg, 20457 Hamburg, Germany
| | - Femke Mussen
- Department of Neuroscience, Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, 3500 Hasselt, Belgium; Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, 6229ER Maastricht, the Netherlands; Department of Immunology and Infection, Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, 3500 Hasselt, Belgium
| | - Elise van Breedam
- Laboratory of Experimental Hematology, Vaccine and Infectious Disease Institute (Vaxinfectio), University of Antwerp, 2610 Wilrijk, Belgium
| | - Peter Ponsaerts
- Laboratory of Experimental Hematology, Vaccine and Infectious Disease Institute (Vaxinfectio), University of Antwerp, 2610 Wilrijk, Belgium
| | - Stefanie Lemmens
- Department of Immunology and Infection, Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, 3500 Hasselt, Belgium
| | - Niels Hellings
- University MS Centre (UMSC) Hasselt - Pelt, Belgium; Department of Immunology and Infection, Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, 3500 Hasselt, Belgium
| | - Roberta Ricciarelli
- IRCCS Ospedale Policlinico San Martino, 16100 Genoa, Italy; Department of Experimental Medicine, Section of General Pathology, University of Genova, 16100 Genoa, Italy
| | - Ernesto Fedele
- IRCCS Ospedale Policlinico San Martino, 16100 Genoa, Italy; Department of Pharmacy, Section of Pharmacology and Toxicology, University of Genoa, 16100 Genoa, Italy
| | - Olga Bruno
- Department of Pharmacy, Section of Medicinal Chemistry, University of Genoa, 16100 Genoa, Italy
| | - Chiara Brullo
- Department of Pharmacy, Section of Medicinal Chemistry, University of Genoa, 16100 Genoa, Italy
| | - Jos Prickaerts
- Peitho Translational, 6229ER Maastricht, the Netherlands
| | - Jana Van Broeckhoven
- University MS Centre (UMSC) Hasselt - Pelt, Belgium; Department of Immunology and Infection, Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, 3500 Hasselt, Belgium
| | - Tim Vanmierlo
- Department of Neuroscience, Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, 3500 Hasselt, Belgium; Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, 6229ER Maastricht, the Netherlands; University MS Centre (UMSC) Hasselt - Pelt, Belgium.
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Dastgheib M, Falak R, Moghaddam MV, Hassanzadeh G, Safa M, Hosseini A. Rolipram and pentoxifylline combination ameliorates the morphological abnormalities of dorsal root ganglion neurons in experimental diabetic neuropathy by reducing mitochondrial dysfunction and apoptosis. J Biochem Mol Toxicol 2023; 37:e23459. [PMID: 37431890 DOI: 10.1002/jbt.23459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 06/20/2023] [Accepted: 07/04/2023] [Indexed: 07/12/2023]
Abstract
Diabetic neuropathy (DN) is the most prevalent complication of diabetes. Pharmacological treatments for DN are often limited in efficacy, so the development of new agents to alleviate DN is essential. The aim of this study was to evaluate the effects of rolipram, a selective phosphodiesterase-4 inhibitor (PDE-4I), and pentoxifylline, a general PDE inhibitor, using a rat model of DN. In this study, a diabetic rat model was established by i.p. injection of STZ (55 mg/kg). Rats were treated with rolipram (1 mg/kg), pentoxifylline (100 mg/kg), and combination of rolipram (0.5 mg/kg) and pentoxifylline (50 mg/kg), orally for 5 weeks. After treatments, sensory function was assessed by hot plate test. Then rats were anesthetized and dorsal root ganglion (DRG) neurons isolated. Cyclic adenosine monophosphate (cAMP), adenosine triphosphate (ATP, adenosine diphosphate and mitochondrial membrane potential (MMP) levels, Cytochrome c release, Bax, Bcl-2, caspase-3 proteins expression in DRG neurons were assessed by biochemical and ELISA methods, and western blot analysis. DRG neurons were histologically examined using hematoxylin and eosin (H&E) staining method. Rolipram and/or pentoxifylline significantly attenuated sensory dysfunction by modulating nociceptive threshold. Rolipram and/or pentoxifylline treatment dramatically increased the cAMP level, prevented mitochondrial dysfunction, apoptosis and degeneration of DRG neurons, which appears to be mediated by inducing ATP and MMP, improving cytochrome c release, as well as regulating the expression of Bax, Bcl-2, and caspase-3 proteins, and improving morphological abnormalities of DRG neurons. We found maximum effectiveness with rolipram and pentoxifylline combination on mentioned factors. These findings encourage the use of rolipram and pentoxifylline combination as a novel experimental evidence for further clinical investigations in the treatment of DN.
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Affiliation(s)
- Mona Dastgheib
- Razi Drug Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Reza Falak
- Department of Immunology, Iran University of Medical Sciences, Tehran, Iran
| | | | | | - Majid Safa
- Department of Hematology and Blood Banking, Faculty of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Asieh Hosseini
- Razi Drug Research Center, Iran University of Medical Sciences, Tehran, Iran
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3
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Gao J, Khang MK, Liao Z, Webb K, Detloff MR, Lee JS. Rolipram-loaded PgP nanoparticle reduces secondary injury and enhances motor function recovery in a rat moderate contusion SCI model. NANOMEDICINE : NANOTECHNOLOGY, BIOLOGY, AND MEDICINE 2023; 53:102702. [PMID: 37574117 DOI: 10.1016/j.nano.2023.102702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 07/30/2023] [Accepted: 08/02/2023] [Indexed: 08/15/2023]
Abstract
Spinal cord injury (SCI) results in immediate axonal damage and cell death, as well as a prolonged secondary injury consist of a cascade of pathophysiological processes. One important aspect of secondary injury is activation of phosphodiesterase 4 (PDE4) that leads to reduce cAMP levels in the injured spinal cord. We have developed an amphiphilic copolymer, poly (lactide-co-glycolide)-graft-polyethylenimine (PgP) that can deliver Rolipram, the PDE4 inhibitor. The objective of this work was to investigate the effect of rolipram loaded PgP (Rm-PgP) on secondary injury and motor functional recovery in a rat moderate contusion SCI model. We observed that Rm-PgP can increase cAMP level at the lesion site, and reduce secondary injury such as the inflammatory response by macrophages/microglia, astrogliosis by activated astrocytes and apoptosis as well as improve neuronal survival at 4 weeks post-injury (WPI). We also observed that Rm-PgP can improve motor functional recovery after SCI over 4 WPI.
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Affiliation(s)
- Jun Gao
- Drug Design Delivery and Development (4D) Laboratory, Department of Bioengineering, Clemson University, Clemson, SC, USA
| | - Min Kyung Khang
- Drug Design Delivery and Development (4D) Laboratory, Department of Bioengineering, Clemson University, Clemson, SC, USA
| | - Zhen Liao
- Drug Design Delivery and Development (4D) Laboratory, Department of Bioengineering, Clemson University, Clemson, SC, USA.
| | - Ken Webb
- MicroEnvironmental Laboratory, Department of Bioengineering, Clemson University, Clemson, SC, USA.
| | - Megan Ryan Detloff
- Department of Neurobiology & Anatomy, Marion Murray Spinal Cord Research Center, College of Medicine, Drexel University, Philadelphia, PA 19129, USA.
| | - Jeoung Soo Lee
- Drug Design Delivery and Development (4D) Laboratory, Department of Bioengineering, Clemson University, Clemson, SC, USA.
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Bonato JM, de Mattos BA, Oliveira DV, Milani H, Prickaerts J, de Oliveira RMW. Blood-Brain Barrier Rescue by Roflumilast After Transient Global Cerebral Ischemia in Rats. Neurotox Res 2023; 41:311-323. [PMID: 36922461 DOI: 10.1007/s12640-023-00639-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 02/28/2023] [Accepted: 03/03/2023] [Indexed: 03/18/2023]
Abstract
Phosphodiesterase 4 inhibitors (PDE4-I), which selectively increase cyclic adenosine monophosphate (cAMP) levels, have shown neuroprotective effects after several neurological injuries inducing blood-brain barrier (BBB) damage including local/focal cerebral ischemia. The present investigated whether roflumilast confers BBB neuroprotection in the hippocampus after transient global cerebral ischemia (TGCI) in rats. TGCI resulted in whole BBB disruption as measured by the increase of Evans blue (EB) and IgG extravasation, neurodegeneration, and downregulation of claudin-5 and endothelial nitric oxide synthase (eNOS) levels in the CA1 hippocampal subfield of ischemic rats. Roflumilast attenuated BBB disruption and restored the levels of eNOS in the CA1 hippocampal area. Moreover, roflumilast increased the levels of B2 cell lymphoma (BcL-2) and neuron-glial antigen-2 (NG2) in the CA1 subfield after global ischemia in rats. The protective effects of roflumilast against TGCI-induced BBB breakdown might involve preservation of BBB integrity, vascularization and angiogenesis, and myelin repair.
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Affiliation(s)
- Jéssica Mendes Bonato
- Department of Pharmacology and Therapeutics, State University of Maringá, Av. Colombo, CEP, 5790, 87020-900, Maringá, Paraná, Brazil
| | - Bianca Andretto de Mattos
- Department of Pharmacology and Therapeutics, State University of Maringá, Av. Colombo, CEP, 5790, 87020-900, Maringá, Paraná, Brazil
| | - Daniela Velasquez Oliveira
- Department of Pharmacology and Therapeutics, State University of Maringá, Av. Colombo, CEP, 5790, 87020-900, Maringá, Paraná, Brazil
| | - Humberto Milani
- Department of Pharmacology and Therapeutics, State University of Maringá, Av. Colombo, CEP, 5790, 87020-900, Maringá, Paraná, Brazil
| | - Jos Prickaerts
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - Rúbia Maria Weffort de Oliveira
- Department of Pharmacology and Therapeutics, State University of Maringá, Av. Colombo, CEP, 5790, 87020-900, Maringá, Paraná, Brazil.
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Sousa CS, Lima R, Cibrão JR, Gomes ED, Fernandes LS, Pinho TS, Silva D, Campos J, Salgado AJ, Silva NA. Pre-Clinical Assessment of Roflumilast Therapy in a Thoracic Model of Spinal Cord Injury. Pharmaceutics 2023; 15:1556. [PMID: 37242797 PMCID: PMC10222626 DOI: 10.3390/pharmaceutics15051556] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 05/14/2023] [Accepted: 05/17/2023] [Indexed: 05/28/2023] Open
Abstract
The failure of axons to regenerate after a spinal cord injury (SCI) remains one of the greatest challenges in neuroscience. The initial mechanical trauma is followed by a secondary injury cascade, creating a hostile microenvironment, which not only is not permissive to regeneration but also leads to further damage. One of the most promising approaches for promoting axonal regeneration is to maintain the levels of cyclic adenosine monophosphate (cAMP), specifically by a phosphodiesterase-4 (PDE4) inhibitor expressed in neural tissues. Therefore, in our study, we evaluated the therapeutic effect of an FDA-approved PDE4 inhibitor, Roflumilast (Rof), in a thoracic contusion rat model. Results indicate that the treatment was effective in promoting functional recovery. Rof-treated animals showed improvements in both gross and fine motor function. Eight weeks post-injury, the animals significantly recovered by achieving occasional weight-supported plantar steps. Histological assessment revealed a significant decrease in cavity size, less reactive microglia, as well as higher axonal regeneration in treated animals. Molecular analysis revealed that IL-10 and IL-13 levels, as well as VEGF, were increased in the serum of Rof-treated animals. Overall, Roflumilast promotes functional recovery and supports neuroregeneration in a severe thoracic contusion injury model and may be important in SCI treatment.
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Affiliation(s)
- Carla S Sousa
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal
- ICVS/3B's Associate Lab, PT Government Associated Lab, 4805-017 Guimarães, Portugal
- Department of Neurosurgery, Hospital Garcia de Orta, 2805-267 Almada, Portugal
| | - Rui Lima
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal
- ICVS/3B's Associate Lab, PT Government Associated Lab, 4805-017 Guimarães, Portugal
| | - Jorge R Cibrão
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal
- ICVS/3B's Associate Lab, PT Government Associated Lab, 4805-017 Guimarães, Portugal
| | - Eduardo D Gomes
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal
- ICVS/3B's Associate Lab, PT Government Associated Lab, 4805-017 Guimarães, Portugal
| | - Luís S Fernandes
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal
- ICVS/3B's Associate Lab, PT Government Associated Lab, 4805-017 Guimarães, Portugal
| | - Tiffany S Pinho
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal
- ICVS/3B's Associate Lab, PT Government Associated Lab, 4805-017 Guimarães, Portugal
| | - Deolinda Silva
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal
- ICVS/3B's Associate Lab, PT Government Associated Lab, 4805-017 Guimarães, Portugal
| | - Jonas Campos
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal
- ICVS/3B's Associate Lab, PT Government Associated Lab, 4805-017 Guimarães, Portugal
| | - António J Salgado
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal
- ICVS/3B's Associate Lab, PT Government Associated Lab, 4805-017 Guimarães, Portugal
| | - Nuno A Silva
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal
- ICVS/3B's Associate Lab, PT Government Associated Lab, 4805-017 Guimarães, Portugal
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Mussen F, Broeckhoven JV, Hellings N, Schepers M, Vanmierlo T. Unleashing Spinal Cord Repair: The Role of cAMP-Specific PDE Inhibition in Attenuating Neuroinflammation and Boosting Regeneration after Traumatic Spinal Cord Injury. Int J Mol Sci 2023; 24:ijms24098135. [PMID: 37175842 PMCID: PMC10179671 DOI: 10.3390/ijms24098135] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 04/27/2023] [Accepted: 04/29/2023] [Indexed: 05/15/2023] Open
Abstract
Traumatic spinal cord injury (SCI) is characterized by severe neuroinflammation and hampered neuroregeneration, which often leads to permanent neurological deficits. Current therapies include decompression surgery, rehabilitation, and in some instances, the use of corticosteroids. However, the golden standard of corticosteroids still achieves minimal improvements in functional outcomes. Therefore, new strategies tackling the initial inflammatory reactions and stimulating endogenous repair in later stages are crucial to achieving functional repair in SCI patients. Cyclic adenosine monophosphate (cAMP) is an important second messenger in the central nervous system (CNS) that modulates these processes. A sustained drop in cAMP levels is observed during SCI, and elevating cAMP is associated with improved functional outcomes in experimental models. cAMP is regulated in a spatiotemporal manner by its hydrolyzing enzyme phosphodiesterase (PDE). Growing evidence suggests that inhibition of cAMP-specific PDEs (PDE4, PDE7, and PDE8) is an important strategy to orchestrate neuroinflammation and regeneration in the CNS. Therefore, this review focuses on the current evidence related to the immunomodulatory and neuroregenerative role of cAMP-specific PDE inhibition in the SCI pathophysiology.
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Affiliation(s)
- Femke Mussen
- Department of Neuroscience, Biomedical Research Institute BIOMED, Hasselt University, 3590 Diepenbeek, Belgium
- University MS Center (UMSC) Hasselt-Pelt, Hasselt University, 3500 Hasselt, Belgium
| | - Jana Van Broeckhoven
- University MS Center (UMSC) Hasselt-Pelt, Hasselt University, 3500 Hasselt, Belgium
- Department of Immunology and Infection, Biomedical Research Institute BIOMED, Hasselt University, 3590 Diepenbeek, Belgium
| | - Niels Hellings
- University MS Center (UMSC) Hasselt-Pelt, Hasselt University, 3500 Hasselt, Belgium
- Department of Immunology and Infection, Biomedical Research Institute BIOMED, Hasselt University, 3590 Diepenbeek, Belgium
| | - Melissa Schepers
- Department of Neuroscience, Biomedical Research Institute BIOMED, Hasselt University, 3590 Diepenbeek, Belgium
- University MS Center (UMSC) Hasselt-Pelt, Hasselt University, 3500 Hasselt, Belgium
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, 6229ER Maastricht, The Netherlands
| | - Tim Vanmierlo
- Department of Neuroscience, Biomedical Research Institute BIOMED, Hasselt University, 3590 Diepenbeek, Belgium
- University MS Center (UMSC) Hasselt-Pelt, Hasselt University, 3500 Hasselt, Belgium
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, 6229ER Maastricht, The Netherlands
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Raue KD, David BT, Fessler RG. Spinal Cord-Gut-Immune Axis and its Implications Regarding Therapeutic Development for Spinal Cord Injury. J Neurotrauma 2023; 40:793-806. [PMID: 36509451 DOI: 10.1089/neu.2022.0264] [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] [Indexed: 12/14/2022] Open
Abstract
Spinal cord injury (SCI) affects ∼1,300,000 people living in the United States. Most research efforts have been focused on reversing paralysis, as this is arguably the most defining feature of SCI. The damage caused by SCI, however, extends past paralysis and includes other debilitating outcomes including immune dysfunction and gut dysbiosis. Recent efforts are now investigating the pathophysiology of and developing therapies for these more distal manifestations of SCI. One exciting avenue is the spinal cord-gut-immune axis, which proposes that gut dysbiosis amplifies lesion inflammation and impairs SCI recovery. This review will highlight the most recent findings regarding gut and immune dysfunction following SCI, and discuss how the central nervous system (CNS), gut, and immune system all coalesce to form a bidirectional axis that can impact SCI recovery. Finally, important considerations regarding how the spinal cord-gut-immune axis fits within the larger framework of therapeutic development (i.e., probiotics, fecal transplants, dietary modifications) will be discussed, emphasizing the lack of interdepartmental investigation and the missed opportunity to maximize therapeutic benefit in SCI.
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Affiliation(s)
- Kristen D Raue
- Department of Neurosurgery, Rush University Medical Center, Chicago, Illinois, USA
| | - Brian T David
- Department of Neurosurgery, Rush University Medical Center, Chicago, Illinois, USA
| | - Richard G Fessler
- Department of Neurosurgery, Rush University Medical Center, Chicago, Illinois, USA
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Schepers M, Paes D, Tiane A, Rombaut B, Piccart E, van Veggel L, Gervois P, Wolfs E, Lambrichts I, Brullo C, Bruno O, Fedele E, Ricciarelli R, Ffrench-Constant C, Bechler ME, van Schaik P, Baron W, Lefevere E, Wasner K, Grünewald A, Verfaillie C, Baeten P, Broux B, Wieringa P, Hellings N, Prickaerts J, Vanmierlo T. Selective PDE4 subtype inhibition provides new opportunities to intervene in neuroinflammatory versus myelin damaging hallmarks of multiple sclerosis. Brain Behav Immun 2023; 109:1-22. [PMID: 36584795 DOI: 10.1016/j.bbi.2022.12.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 12/17/2022] [Accepted: 12/24/2022] [Indexed: 12/29/2022] Open
Abstract
Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system (CNS) characterized by focal inflammatory lesions and prominent demyelination. Even though the currently available therapies are effective in treating the initial stages of disease, they are unable to halt or reverse disease progression into the chronic progressive stage. Thus far, no repair-inducing treatments are available for progressive MS patients. Hence, there is an urgent need for the development of new therapeutic strategies either targeting the destructive immunological demyelination or boosting endogenous repair mechanisms. Using in vitro, ex vivo, and in vivo models, we demonstrate that selective inhibition of phosphodiesterase 4 (PDE4), a family of enzymes that hydrolyzes and inactivates cyclic adenosine monophosphate (cAMP), reduces inflammation and promotes myelin repair. More specifically, we segregated the myelination-promoting and anti-inflammatory effects into a PDE4D- and PDE4B-dependent process respectively. We show that inhibition of PDE4D boosts oligodendrocyte progenitor cells (OPC) differentiation and enhances (re)myelination of both murine OPCs and human iPSC-derived OPCs. In addition, PDE4D inhibition promotes in vivo remyelination in the cuprizone model, which is accompanied by improved spatial memory and reduced visual evoked potential latency times. We further identified that PDE4B-specific inhibition exerts anti-inflammatory effects since it lowers in vitro monocytic nitric oxide (NO) production and improves in vivo neurological scores during the early phase of experimental autoimmune encephalomyelitis (EAE). In contrast to the pan PDE4 inhibitor roflumilast, the therapeutic dose of both the PDE4B-specific inhibitor A33 and the PDE4D-specific inhibitor Gebr32a did not trigger emesis-like side effects in rodents. Finally, we report distinct PDE4D isoform expression patterns in human area postrema neurons and human oligodendroglia lineage cells. Using the CRISPR-Cas9 system, we confirmed that pde4d1/2 and pde4d6 are the key targets to induce OPC differentiation. Collectively, these data demonstrate that gene specific PDE4 inhibitors have potential as novel therapeutic agents for targeting the distinct disease processes of MS.
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Affiliation(s)
- Melissa Schepers
- Department of Neuroscience, Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium; Department Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands; University MS Center (UMSC) Hasselt-Pelt, Hasselt, Belgium
| | - Dean Paes
- Department of Neuroscience, Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium; Department Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Assia Tiane
- Department of Neuroscience, Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium; Department Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands; University MS Center (UMSC) Hasselt-Pelt, Hasselt, Belgium
| | - Ben Rombaut
- Department of Neuroscience, Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium; Department Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Elisabeth Piccart
- Department of Neuroscience, Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium
| | - Lieve van Veggel
- Department of Neuroscience, Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium; Department Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands; University MS Center (UMSC) Hasselt-Pelt, Hasselt, Belgium
| | - Pascal Gervois
- Department of Cardio and Organ Systems, Biomedical Research Institute, Hasselt University, Diepenbeek, Belgium
| | - Esther Wolfs
- Department of Cardio and Organ Systems, Biomedical Research Institute, Hasselt University, Diepenbeek, Belgium
| | - Ivo Lambrichts
- Department of Cardio and Organ Systems, Biomedical Research Institute, Hasselt University, Diepenbeek, Belgium
| | - Chiara Brullo
- Department of Pharmacy, Section of Medicinal Chemistry, University of Genoa, Genova, Italy
| | - Olga Bruno
- Department of Pharmacy, Section of Medicinal Chemistry, University of Genoa, Genova, Italy
| | - Ernesto Fedele
- Department of Pharmacy, Section of Pharmacology and Toxicology, University of Genova, Genova, Italy; IRCCS Ospedale Policlinico San Martino, Genova, Italy
| | - Roberta Ricciarelli
- IRCCS Ospedale Policlinico San Martino, Genova, Italy; Department of Experimental Medicine, Section of General Pathology, University of Genova, Genova, Italy
| | - Charles Ffrench-Constant
- MRC Centre for Regenerative Medicine and MS Society Edinburgh Centre, Edinburgh bioQuarter, University of Edinburgh, Edinburgh, UK
| | - Marie E Bechler
- Department of Cell and Developmental Biology, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Pauline van Schaik
- Department of Biomedical Sciences of Cells and Systems, Section Molecular Neurobiology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Wia Baron
- Department of Biomedical Sciences of Cells and Systems, Section Molecular Neurobiology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Evy Lefevere
- Rewind Therapeutics NV, Gaston Geenslaan 2, B-3001, Leuven, Belgium
| | - Kobi Wasner
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Anne Grünewald
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Catherine Verfaillie
- Stem Cell Institute, Department of Development and Regeneration, KU Leuven, Belgium
| | - Paulien Baeten
- University MS Center (UMSC) Hasselt-Pelt, Hasselt, Belgium; Department of Immunology and Infection, Biomedical Research Institute, Hasselt University, Diepenbeek, Belgium
| | - Bieke Broux
- University MS Center (UMSC) Hasselt-Pelt, Hasselt, Belgium; Department of Immunology and Infection, Biomedical Research Institute, Hasselt University, Diepenbeek, Belgium
| | - Paul Wieringa
- MERLN Institute for Technology-Inspired Regenerative Medicine, Complex Tissue Regeneration department, Maastricht University, Maastricht, the Netherlands
| | - Niels Hellings
- University MS Center (UMSC) Hasselt-Pelt, Hasselt, Belgium; Department of Immunology and Infection, Biomedical Research Institute, Hasselt University, Diepenbeek, Belgium
| | - Jos Prickaerts
- Department Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Tim Vanmierlo
- Department of Neuroscience, Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium; Department Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands; University MS Center (UMSC) Hasselt-Pelt, Hasselt, Belgium.
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9
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Jin Y, Song Y, Lin J, Liu T, Li G, Lai B, Gu Y, Chen G, Xing L. Role of inflammation in neurological damage and regeneration following spinal cord injury and its therapeutic implications. BURNS & TRAUMA 2023; 11:tkac054. [PMID: 36873284 PMCID: PMC9976751 DOI: 10.1093/burnst/tkac054] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 07/07/2022] [Accepted: 12/01/2022] [Indexed: 03/06/2023]
Abstract
Spinal cord injury (SCI) is an incurable trauma that frequently results in partial or complete loss of motor and sensory function. Massive neurons are damaged after the initial mechanical insult. Secondary injuries, which are triggered by immunological and inflammatory responses, also result in neuronal loss and axon retraction. This results in defects in the neural circuit and a deficiency in the processing of information. Although inflammatory responses are necessary for spinal cord recovery, conflicting evidence of their contributions to specific biological processes have made it difficult to define the specific role of inflammation in SCI. This review summarizes our understanding of the complex role of inflammation in neural circuit events following SCI, such as cell death, axon regeneration and neural remodeling. We also review the drugs that regulate immune responses and inflammation in the treatment of SCI and discuss the roles of these drugs in the modulation of neural circuits. Finally, we provide evidence about the critical role of inflammation in facilitating spinal cord neural circuit regeneration in zebrafish, an animal model with robust regenerative capacity, to provide insights into the regeneration of the mammalian central nervous system.
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Affiliation(s)
- Yan Jin
- Key Laboratory of Neuroregeneration of Jiangsu and the Ministry of Education, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products,Nantong University, Nantong 226006, China.,School of Life Sciences, Nantong University, Nantong 226019, China
| | - Yixing Song
- Key Laboratory of Neuroregeneration of Jiangsu and the Ministry of Education, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products,Nantong University, Nantong 226006, China
| | - Jiaqi Lin
- School of Medicine, Nantong University, Nantong 226006, China
| | - Tianqing Liu
- NICM Health Research Institute, Western Sydney University, Westmead, NSW 2145, Australia
| | - Guicai Li
- Key Laboratory of Neuroregeneration of Jiangsu and the Ministry of Education, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products,Nantong University, Nantong 226006, China
| | - Biqin Lai
- Key Laboratory for Stem Cells and Tissue Engineering (Sun Yat-sen University), Ministry of Education, Guangzhou 510275, China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong 226006, China
| | - Yun Gu
- Key Laboratory of Neuroregeneration of Jiangsu and the Ministry of Education, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products,Nantong University, Nantong 226006, China
| | - Gang Chen
- School of Medicine, Nantong University, Nantong 226006, China
| | - Lingyan Xing
- Key Laboratory of Neuroregeneration of Jiangsu and the Ministry of Education, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products,Nantong University, Nantong 226006, China
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10
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Zhou G, Wang Z, Han S, Chen X, Li Z, Hu X, Li Y, Gao J. Multifaceted Roles of cAMP Signaling in the Repair Process of Spinal Cord Injury and Related Combination Treatments. Front Mol Neurosci 2022; 15:808510. [PMID: 35283731 PMCID: PMC8904388 DOI: 10.3389/fnmol.2022.808510] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 01/26/2022] [Indexed: 01/03/2023] Open
Abstract
Spinal cord injury (SCI) results in multiple pathophysiological processes, including blood–spinal cord barrier disruption, hemorrhage/ischemia, oxidative stress, neuroinflammation, scar formation, and demyelination. These responses eventually lead to severe tissue destruction and an inhibitory environment for neural regeneration.cAMP signaling is vital for neurite outgrowth and axonal guidance. Stimulating intracellular cAMP activity significantly promotes neuronal survival and axonal regrowth after SCI.However, neuronal cAMP levels in adult CNS are relatively low and will further decrease after injury. Targeting cAMP signaling has become a promising strategy for neural regeneration over the past two decades. Furthermore, studies have revealed that cAMP signaling is involved in the regulation of glial cell function in the microenvironment of SCI, including macrophages/microglia, reactive astrocytes, and oligodendrocytes. cAMP-elevating agents in the post-injury milieu increase the cAMP levels in both neurons and glial cells and facilitate injury repair through the interplay between neurons and glial cells and ultimately contribute to better morphological and functional outcomes. In recent years, combination treatments associated with cAMP signaling have been shown to exert synergistic effects on the recovery of SCI. Agents carried by nanoparticles exhibit increased water solubility and capacity to cross the blood–spinal cord barrier. Implanted bioscaffolds and injected hydrogels are potential carriers to release agents locally to avoid systemic side effects. Cell transplantation may provide permissive matrices to synergize with the cAMP-enhanced growth capacity of neurons. cAMP can also induce the oriented differentiation of transplanted neural stem/progenitor cells into neurons and increase the survival rate of cell grafts. Emerging progress focused on cAMP compartmentation provides researchers with new perspectives to understand the complexity of downstream signaling, which may facilitate the clinical translation of strategies targeting cAMP signaling for SCI repair.
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Affiliation(s)
- Gang Zhou
- Department of Neurosurgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Zhiyan Wang
- Plastic Surgery Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Shiyuan Han
- Department of Neurosurgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Xiaokun Chen
- Department of Neurosurgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Zhimin Li
- Department of Neurosurgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Xianghui Hu
- Department of Neurosurgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Yongning Li
- Department of Neurosurgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
- Department of International Medical Service, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Jun Gao
- Department of Neurosurgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
- *Correspondence: Jun Gao
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11
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Megat S, Hugel S, Journée SH, Bohren Y, Lacaud A, Lelièvre V, Doridot S, Villa P, Bourguignon JJ, Salvat E, Schlichter R, Freund-Mercier MJ, Yalcin I, Barrot M. Antiallodynic action of phosphodiesterase inhibitors in a mouse model of peripheral nerve injury. Neuropharmacology 2021; 205:108909. [PMID: 34875284 DOI: 10.1016/j.neuropharm.2021.108909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 10/01/2021] [Accepted: 11/28/2021] [Indexed: 11/30/2022]
Abstract
Neuropathic pain arises as a consequence of a lesion or disease affecting the somatosensory nervous system. It is accompanied by neuronal and non-neuronal alterations, including alterations in intracellular second messenger pathways. Cellular levels of 3',5'-cyclic adenosine monophosphate (cAMP) and 3',5'-cyclic guanosine monophosphate (cGMP) are regulated by phosphodiesterase (PDE) enzymes. Here, we studied the impact of PDE inhibitors (PDEi) in a mouse model of peripheral nerve injury induced by placing a cuff around the main branch of the sciatic nerve. Mechanical hypersensitivity, evaluated using von Frey filaments, was relieved by sustained treatment with the non-selective PDEi theophylline and ibudilast (AV-411), with PDE4i rolipram, etazolate and YM-976, and with PDE5i sildenafil, zaprinast and MY-5445, but not by treatments with PDE1i vinpocetine, PDE2i EHNA or PDE3i milrinone. Using pharmacological and knock-out approaches, we show a preferential implication of delta opioid receptors in the action of the PDE4i rolipram and of both mu and delta opioid receptors in the action of the PDE5i sildenafil. Calcium imaging highlighted a preferential action of rolipram on dorsal root ganglia non-neuronal cells, through PDE4B and PDE4D inhibition. Rolipram had anti-neuroimmune action, as shown by its impact on levels of the pro-inflammatory cytokine tumor necrosis factor-α (TNFα) in the dorsal root ganglia of mice with peripheral nerve injury, as well as in human peripheral blood mononuclear cells (PBMCs) stimulated with lipopolysaccharides. This study suggests that PDEs, especially PDE4 and 5, may be targets of interest in the treatment of neuropathic pain.
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Affiliation(s)
- Salim Megat
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg, France
| | - Sylvain Hugel
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg, France
| | - Sarah H Journée
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg, France
| | - Yohann Bohren
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg, France; Hôpitaux Universitaires de Strasbourg, Centre d'Evaluation et de Traitement de la Douleur, Strasbourg, France
| | - Adrien Lacaud
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg, France
| | - Vincent Lelièvre
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg, France
| | - Stéphane Doridot
- Centre National de la Recherche Scientifique, Université de Strasbourg, Chronobiotron, Strasbourg, France
| | - Pascal Villa
- Université de Strasbourg, Centre National de la Recherche Scientifique, Plateforme de Chimie Biologique Intégrative de Strasbourg, UAR3286, Illkirch, France
| | - Jean-Jacques Bourguignon
- Université de Strasbourg, Centre National de la Recherche Scientifique, Laboratoire d'Innovation Thérapeutique, Illkirch, France
| | - Eric Salvat
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg, France; Hôpitaux Universitaires de Strasbourg, Centre d'Evaluation et de Traitement de la Douleur, Strasbourg, France
| | - Remy Schlichter
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg, France
| | - Marie-José Freund-Mercier
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg, France
| | - Ipek Yalcin
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg, France.
| | - Michel Barrot
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg, France.
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12
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Ainatzoglou A, Stamoula E, Dardalas I, Siafis S, Papazisis G. The Effects of PDE Inhibitors on Multiple Sclerosis: a Review of in vitro and in vivo Models. Curr Pharm Des 2021; 27:2387-2397. [PMID: 33655851 DOI: 10.2174/1381612827666210303142356] [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: 10/12/2020] [Accepted: 02/11/2021] [Indexed: 11/22/2022]
Abstract
BACKGROUND Multiple sclerosis (MS) is a chronic inflammatory and immune-mediated disease, whose current therapeutic means are mostly effective in the relapsing-remitting form of MS, where inflammation is still prominent, but fall short of preventing long term impairment. However, apart from inflammationmediated demyelination, autoimmune mechanisms play a major role in MS pathophysiology, constituting a promising pharmacological target. Phosphodiesterase (PDE) inhibitors have been approved for clinical use in psoriasis and have undergone trials suggesting their neuroprotective effects, rendering them eligible as an option for accessory MS therapy. OBJECTIVE In this review, we discuss the potential role of PDE inhibitors as a complementary MS therapy. METHODS We conducted a literature search through which we screened and comparatively assessed papers on the effects of PDE inhibitor use, both in vitro and in animal models of MS, taking into account a number of inclusion and exclusion criteria. RESULTS In vitro studies indicated that PDE inhibitors promote remyelination and axonal sustenance, while curbing inflammatory cell infiltration, hindering oligodendrocyte and neuronal loss and suppressing cytokine production. In vivo studies underlined that these agents alleviate symptoms and reduce disease scores in MS animal models. CONCLUSION PDE inhibitors proved to be effective in addressing various aspects of MS pathogenesis both in vitro and in vivo models. Given the latest clinical trials proving that the PDE4 inhibitor Ibudilast exerts neuroprotective effects in patients with progressive MS, research on this field should be intensified and selective PDE4 inhibitors with enhanced safety features should be seriously considered as prospective complementary MS therapy.
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Affiliation(s)
- Alexandra Ainatzoglou
- Department of Clinical Pharmacology, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Eleni Stamoula
- Department of Clinical Pharmacology, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Ioannis Dardalas
- Department of Clinical Pharmacology, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Spyridon Siafis
- Department of Clinical Pharmacology, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Georgios Papazisis
- Department of Clinical Pharmacology, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece
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13
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Schepers M, Tiane A, Paes D, Sanchez S, Rombaut B, Piccart E, Rutten BPF, Brône B, Hellings N, Prickaerts J, Vanmierlo T. Targeting Phosphodiesterases-Towards a Tailor-Made Approach in Multiple Sclerosis Treatment. Front Immunol 2019; 10:1727. [PMID: 31396231 PMCID: PMC6667646 DOI: 10.3389/fimmu.2019.01727] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 07/09/2019] [Indexed: 12/11/2022] Open
Abstract
Multiple sclerosis (MS) is a chronic demyelinating disease of the central nervous system (CNS) characterized by heterogeneous clinical symptoms including gradual muscle weakness, fatigue, and cognitive impairment. The disease course of MS can be classified into a relapsing-remitting (RR) phase defined by periods of neurological disabilities, and a progressive phase where neurological decline is persistent. Pathologically, MS is defined by a destructive immunological and neuro-degenerative interplay. Current treatments largely target the inflammatory processes and slow disease progression at best. Therefore, there is an urgent need to develop next-generation therapeutic strategies that target both neuroinflammatory and degenerative processes. It has been shown that elevating second messengers (cAMP and cGMP) is important for controlling inflammatory damage and inducing CNS repair. Phosphodiesterases (PDEs) have been studied extensively in a wide range of disorders as they breakdown these second messengers, rendering them crucial regulators. In this review, we provide an overview of the role of PDE inhibition in limiting pathological inflammation and stimulating regenerative processes in MS.
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Affiliation(s)
- Melissa Schepers
- Department of Neuroimmunology, European Graduate School of Neuroscience, Biomedical Research Institute, Hasselt University, Hasselt, Belgium.,Department Psychiatry and Neuropsychology, European Graduate School of Neuroscience, School for Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Assia Tiane
- Department of Neuroimmunology, European Graduate School of Neuroscience, Biomedical Research Institute, Hasselt University, Hasselt, Belgium.,Department Psychiatry and Neuropsychology, European Graduate School of Neuroscience, School for Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Dean Paes
- Department of Neuroimmunology, European Graduate School of Neuroscience, Biomedical Research Institute, Hasselt University, Hasselt, Belgium.,Department Psychiatry and Neuropsychology, European Graduate School of Neuroscience, School for Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Selien Sanchez
- Department of Morphology, Biomedical Research Institute, Hasselt University, Hasselt, Belgium
| | - Ben Rombaut
- Department of Physiology, Biomedical Research Institute, Hasselt University, Hasselt, Belgium
| | - Elisabeth Piccart
- Department of Neuroimmunology, European Graduate School of Neuroscience, Biomedical Research Institute, Hasselt University, Hasselt, Belgium.,Department Psychiatry and Neuropsychology, European Graduate School of Neuroscience, School for Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Bart P F Rutten
- Department Psychiatry and Neuropsychology, European Graduate School of Neuroscience, School for Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Bert Brône
- Department of Physiology, Biomedical Research Institute, Hasselt University, Hasselt, Belgium
| | - Niels Hellings
- Department of Neuroimmunology, European Graduate School of Neuroscience, Biomedical Research Institute, Hasselt University, Hasselt, Belgium
| | - Jos Prickaerts
- Department Psychiatry and Neuropsychology, European Graduate School of Neuroscience, School for Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Tim Vanmierlo
- Department of Neuroimmunology, European Graduate School of Neuroscience, Biomedical Research Institute, Hasselt University, Hasselt, Belgium.,Department Psychiatry and Neuropsychology, European Graduate School of Neuroscience, School for Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands
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14
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Goonoo N, Bhaw-Luximon A. Mimicking growth factors: role of small molecule scaffold additives in promoting tissue regeneration and repair. RSC Adv 2019; 9:18124-18146. [PMID: 35702423 PMCID: PMC9115879 DOI: 10.1039/c9ra02765c] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 06/02/2019] [Indexed: 12/31/2022] Open
Abstract
The primary aim of tissue engineering scaffolds is to mimic the in vivo environment and promote tissue growth. In this quest, a number of strategies have been developed such as enhancing cell-material interactions through modulation of scaffold physico-chemical parameters. However, more is required for scaffolds to relate to the cell natural environment. Growth factors (GFs) secreted by cells and extracellular matrix (ECM) are involved in both normal repair and abnormal remodeling. The direct use of GFs on their own or when incorporated within scaffolds represent a number of challenges such as release rate, stability and shelf-life. Small molecules have been proposed as promising alternatives to GFs as they are able to minimize or overcome many shortcomings of GFs, in particular immune response and instability. Despite the promise of small molecules in various TE applications, their direct use is limited by nonspecific adverse effects on non-target tissues and organs. Hence, they have been incorporated within scaffolds to localize their actions and control their release to target sites. However, scanty rationale is available which links the chemical structure of these molecules with their mode of action. We herewith review various small molecules either when used on their own or when incorporated within polymeric carriers/scaffolds for bone, cartilage, neural, adipose and skin tissue regeneration.
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Affiliation(s)
- Nowsheen Goonoo
- Biomaterials, Drug Delivery and Nanotechnology (BDDN) Unit, Centre for Biomedical and Biomaterials Research, University of Mauritius Réduit Mauritius
| | - Archana Bhaw-Luximon
- Biomaterials, Drug Delivery and Nanotechnology (BDDN) Unit, Centre for Biomedical and Biomaterials Research, University of Mauritius Réduit Mauritius
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15
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Myers SA, Gobejishvili L, Saraswat Ohri S, Garrett Wilson C, Andres KR, Riegler AS, Donde H, Joshi-Barve S, Barve S, Whittemore SR. Following spinal cord injury, PDE4B drives an acute, local inflammatory response and a chronic, systemic response exacerbated by gut dysbiosis and endotoxemia. Neurobiol Dis 2018; 124:353-363. [PMID: 30557659 DOI: 10.1016/j.nbd.2018.12.008] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 12/03/2018] [Accepted: 12/13/2018] [Indexed: 02/06/2023] Open
Abstract
Emerging evidence links changes in the gut microbiome and intestinal barrier function to alterations in CNS function. We examined the role of endotoxin-responsive, cAMP-specific, Pde4 subfamily b (Pde4b) enzyme in gut dysbiosis induced neuro-inflammation and white matter loss following spinal cord injury (SCI). Using a thoracic contusion model in C57Bl/6 wild type female mice, SCI led to significant shifts in the gut bacterial community including an increase in the phylum Proteobacteria, which consists of endotoxin-harboring, gram-negative bacteria. This was accompanied by increased systemic inflammatory marker, soluble CD14, along with markers of the endoplasmic reticulum stress response (ERSR) and inflammation in the SCI epicenter. Deletion of Pde4b reduced epicenter expression of markers for the ERSR and inflammation, at both acute and chronic time points post-SCI. Correspondingly, expression of oligodendrocyte mRNAs increased. Within the injury penumbra, inflammatory protein markers of activated astrocytes (GFAP), macrophage/microglia (CD11b, Iba1), and the proinflammatory mediator Cox2, were decreased in Pde4b-/- mice. The absence of Pde4b improved white matter sparing and recovery of hindlimb locomotion following injury. Importantly, SCI-induced gut dysbiosis, bacterial overgrowth and endotoxemia were also prevented in Pde4b-/- mice. Taken together, these findings indicate that PDE4B plays an important role in the development of acute and chronic inflammatory response and consequent recovery following SCI.
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Affiliation(s)
- Scott A Myers
- Kentucky Spinal Cord Injury Research Center, University of Louisville, School of Medicine, 511 S. Floyd St., MDR 616, Louisville, KY 40202, USA; Department of Neurological Surgery, University of Louisville, School of Medicine, 511 S. Floyd St., MDR 616, Louisville, KY 40202, USA
| | - Leila Gobejishvili
- Departments of Internal Medicine and Pharmacology and Toxicology, and Alcohol Research Center, University of Louisville, School of Medicine, 505 South Hancock Street, CTR Building, Room 515, Louisville, KY 40202, USA
| | - Sujata Saraswat Ohri
- Kentucky Spinal Cord Injury Research Center, University of Louisville, School of Medicine, 511 S. Floyd St., MDR 616, Louisville, KY 40202, USA; Department of Neurological Surgery, University of Louisville, School of Medicine, 511 S. Floyd St., MDR 616, Louisville, KY 40202, USA
| | - C Garrett Wilson
- UAB School of Medicine, University of Alabama at Birmingham, Bevill Biomedical Research Building, Birmingham, AL 35294, USA
| | - Kariena R Andres
- Kentucky Spinal Cord Injury Research Center, University of Louisville, School of Medicine, 511 S. Floyd St., MDR 616, Louisville, KY 40202, USA; Department of Neurological Surgery, University of Louisville, School of Medicine, 511 S. Floyd St., MDR 616, Louisville, KY 40202, USA
| | - Amberly S Riegler
- Kentucky Spinal Cord Injury Research Center, University of Louisville, School of Medicine, 511 S. Floyd St., MDR 616, Louisville, KY 40202, USA; Department of Neurological Surgery, University of Louisville, School of Medicine, 511 S. Floyd St., MDR 616, Louisville, KY 40202, USA
| | - Hridgandh Donde
- Departments of Internal Medicine and Pharmacology and Toxicology, and Alcohol Research Center, University of Louisville, School of Medicine, 505 South Hancock Street, CTR Building, Room 515, Louisville, KY 40202, USA
| | - Swati Joshi-Barve
- Departments of Internal Medicine and Pharmacology and Toxicology, and Alcohol Research Center, University of Louisville, School of Medicine, 505 South Hancock Street, CTR Building, Room 515, Louisville, KY 40202, USA
| | - Shirish Barve
- Departments of Internal Medicine and Pharmacology and Toxicology, and Alcohol Research Center, University of Louisville, School of Medicine, 505 South Hancock Street, CTR Building, Room 515, Louisville, KY 40202, USA.
| | - Scott R Whittemore
- Kentucky Spinal Cord Injury Research Center, University of Louisville, School of Medicine, 511 S. Floyd St., MDR 616, Louisville, KY 40202, USA; Department of Neurological Surgery, University of Louisville, School of Medicine, 511 S. Floyd St., MDR 616, Louisville, KY 40202, USA; Department of Anatomical Science & Neurobiology, University of Louisville, School of Medicine, 511 S. Floyd St., MDR 616, Louisville, KY 40202, USA.
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16
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Protective role of β-carotene against oxidative stress and neuroinflammation in a rat model of spinal cord injury. Int Immunopharmacol 2018; 61:92-99. [DOI: 10.1016/j.intimp.2018.05.022] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 05/20/2018] [Accepted: 05/23/2018] [Indexed: 12/25/2022]
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17
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Macks C, Gwak SJ, Lynn M, Lee JS. Rolipram-Loaded Polymeric Micelle Nanoparticle Reduces Secondary Injury after Rat Compression Spinal Cord Injury. J Neurotrauma 2018; 35:582-592. [PMID: 29065765 DOI: 10.1089/neu.2017.5092] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Among the complex pathophysiological events following spinal cord injury (SCI), one of the most important molecular level consequences is a dramatic reduction in neuronal cyclic adenosine monophosphate (cAMP) levels. Many studies shown that rolipram (Rm), a phosphodiesterase IV inhibitor, can protect against secondary cell death, reduce inflammatory cytokine levels and immune cell infiltration, and increase white matter sparing and functional improvement. Previously, we developed a polymeric micelle nanoparticle, poly(lactide-co-glycolide)-graft-polyethylenimine (PgP), for combinatorial delivery of therapeutic nucleic acids and drugs for SCI repair. In this study, we evaluated PgP as an Rm delivery carrier for SCI repair. Rolipram's water solubility was increased ∼6.8 times in the presence of PgP, indicating drug solubilization in the micelle hydrophobic core. Using hypoxia as an in vitro SCI model, Rm-loaded PgP (Rm-PgP) restored cAMP levels and increased neuronal cell survival of cerebellar granular neurons. The potential efficacy of Rm-PgP was evaluated in a rat compression SCI model. After intraspinal injection, 1,1'-dioctadecyl-3,3,3',3'-tetramethyl indotricarbocyanine Iodide-loaded PgP micelles were retained at the injection site for up to 5 days. Finally, we show that a single injection of Rm-PgP nanoparticles restored cAMP in the SCI lesion site and reduced apoptosis and the inflammatory response. These results suggest that PgP may offer an efficient and translational approach to delivering Rm as a neuroprotectant following SCI.
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Affiliation(s)
- Christian Macks
- 1 Department of Bioengineering, Clemson University , Clemson, South Carolina
| | - So-Jung Gwak
- 1 Department of Bioengineering, Clemson University , Clemson, South Carolina
| | - Michael Lynn
- 2 Department of Neurosurgery, Greenville Health System , Greenville, South Carolina
| | - Jeoung Soo Lee
- 1 Department of Bioengineering, Clemson University , Clemson, South Carolina
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18
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Knott EP, Assi M, Rao SNR, Ghosh M, Pearse DD. Phosphodiesterase Inhibitors as a Therapeutic Approach to Neuroprotection and Repair. Int J Mol Sci 2017; 18:E696. [PMID: 28338622 PMCID: PMC5412282 DOI: 10.3390/ijms18040696] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 03/10/2017] [Accepted: 03/15/2017] [Indexed: 12/21/2022] Open
Abstract
A wide diversity of perturbations of the central nervous system (CNS) result in structural damage to the neuroarchitecture and cellular defects, which in turn are accompanied by neurological dysfunction and abortive endogenous neurorepair. Altering intracellular signaling pathways involved in inflammation and immune regulation, neural cell death, axon plasticity and remyelination has shown therapeutic benefit in experimental models of neurological disease and trauma. The second messengers, cyclic adenosine monophosphate (cyclic AMP) and cyclic guanosine monophosphate (cyclic GMP), are two such intracellular signaling targets, the elevation of which has produced beneficial cellular effects within a range of CNS pathologies. The only known negative regulators of cyclic nucleotides are a family of enzymes called phosphodiesterases (PDEs) that hydrolyze cyclic nucleotides into adenosine monophosphate (AMP) or guanylate monophosphate (GMP). Herein, we discuss the structure and physiological function as well as the roles PDEs play in pathological processes of the diseased or injured CNS. Further we review the approaches that have been employed therapeutically in experimental paradigms to block PDE expression or activity and in turn elevate cyclic nucleotide levels to mediate neuroprotection or neurorepair as well as discuss both the translational pathway and current limitations in moving new PDE-targeted therapies to the clinic.
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Affiliation(s)
- Eric P Knott
- Herbert Wertheim College of Medicine, Florida International University, Miami, FL 33199, USA.
| | - Mazen Assi
- The Miami Project to Cure Paralysis, The Miller School of Medicine at the University of Miami, Miami, FL 33136, USA.
| | - Sudheendra N R Rao
- The Miami Project to Cure Paralysis, The Miller School of Medicine at the University of Miami, Miami, FL 33136, USA.
| | - Mousumi Ghosh
- The Miami Project to Cure Paralysis, The Miller School of Medicine at the University of Miami, Miami, FL 33136, USA.
- The Department of Neurological Surgery, The Miller School of Medicine at the University of Miami, Miami, FL 33136, USA.
| | - Damien D Pearse
- The Miami Project to Cure Paralysis, The Miller School of Medicine at the University of Miami, Miami, FL 33136, USA.
- The Department of Neurological Surgery, The Miller School of Medicine at the University of Miami, Miami, FL 33136, USA.
- The Neuroscience Program, The Miller School of Medicine at the University of Miami, Miami, FL 33136, USA.
- The Interdisciplinary Stem Cell Institute, The Miller School of Medicine at the University of Miami, Miami, FL 33136, USA.
- Bruce Wayne Carter Department of Veterans Affairs Medical Center, Miami, FL 33136, USA.
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Kilanczyk E, Saraswat Ohri S, Whittemore SR, Hetman M. Antioxidant Protection of NADPH-Depleted Oligodendrocyte Precursor Cells Is Dependent on Supply of Reduced Glutathione. ASN Neuro 2016; 8:8/4/1759091416660404. [PMID: 27449129 PMCID: PMC4962338 DOI: 10.1177/1759091416660404] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 06/29/2016] [Indexed: 01/02/2023] Open
Abstract
The pentose phosphate pathway is the main source of NADPH, which by reducing oxidized glutathione, contributes to antioxidant defenses. Although oxidative stress plays a major role in white matter injury, significance of NADPH for oligodendrocyte survival has not been yet investigated. It is reported here that the NADPH antimetabolite 6-amino-NADP (6AN) was cytotoxic to cultured adult rat spinal cord oligodendrocyte precursor cells (OPCs) as well as OPC-derived oligodendrocytes. The 6AN-induced necrosis was preceded by increased production of superoxide, NADPH depletion, and lower supply of reduced glutathione. Moreover, survival of NADPH-depleted OPCs was improved by the antioxidant drug trolox. Such cells were also protected by physiological concentrations of the neurosteroid dehydroepiandrosterone (10−8 M). The protection by dehydroepiandrosterone was associated with restoration of reduced glutathione, but not NADPH, and was sensitive to inhibition of glutathione synthesis. A similar protective mechanism was engaged by the cAMP activator forskolin or the G protein-coupled estrogen receptor (GPER/GPR30) ligand G1. Finally, treatment with the glutathione precursor N-acetyl cysteine reduced cytotoxicity of 6AN. Taken together, NADPH is critical for survival of OPCs by supporting their antioxidant defenses. Consequently, injury-associated inhibition of the pentose phosphate pathway may be detrimental for the myelination or remyelination potential of the white matter. Conversely, steroid hormones and cAMP activators may promote survival of NADPH-deprived OPCs by increasing a NADPH-independent supply of reduced glutathione. Therefore, maintenance of glutathione homeostasis appears as a critical effector mechanism for OPC protection against NADPH depletion and preservation of the regenerative potential of the injured white matter.
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Affiliation(s)
- Ewa Kilanczyk
- Kentucky Spinal Cord Injury Research Center, University of Louisville, KY, USA Department of Neurological Surgery, University of Louisville, KY, USA
| | - Sujata Saraswat Ohri
- Kentucky Spinal Cord Injury Research Center, University of Louisville, KY, USA Department of Neurological Surgery, University of Louisville, KY, USA
| | - Scott R Whittemore
- Kentucky Spinal Cord Injury Research Center, University of Louisville, KY, USA Department of Neurological Surgery, University of Louisville, KY, USA Department of Anatomical Sciences and Neurobiology, University of Louisville, KY, USA
| | - Michal Hetman
- Kentucky Spinal Cord Injury Research Center, University of Louisville, KY, USA Department of Neurological Surgery, University of Louisville, KY, USA Department of Pharmacology and Toxicology, University of Louisville, KY, USA
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JI QING, DI YAN, HE XIAOYUN, LIU QINGZHEN, LIU JIAN, LI WEIYAN, ZHANG LIDONG. Intrathecal injection of phosphodiesterase 4B-specific siRNA attenuates neuropathic pain in rats with L5 spinal nerve ligation. Mol Med Rep 2015; 13:1914-22. [DOI: 10.3892/mmr.2015.4713] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Accepted: 11/30/2015] [Indexed: 11/06/2022] Open
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Singh PL, Agarwal N, Barrese JC, Heary RF. Current therapeutic strategies for inflammation following traumatic spinal cord injury. Neural Regen Res 2015; 7:1812-21. [PMID: 25624806 PMCID: PMC4302532 DOI: 10.3969/j.issn.1673-5374.2012.23.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2012] [Accepted: 05/14/2012] [Indexed: 11/18/2022] Open
Abstract
Damage from spinal cord injury occurs in two phases – the trauma of the initial mechanical insult and a secondary injury to nervous tissue spared by the primary insult. Apart from damage sustained as a result of direct trauma to the spinal cord, the post-traumatic inflammatory response contributes significantly to functional motor deficits exacerbated by the secondary injury. Attenuating the detrimental aspects of the inflammatory response is a promising strategy to potentially ameliorate the secondary injury, and promote significant functional recovery. This review details how the inflammatory component of secondary injury to the spinal cord can be treated currently and in the foreseeable future.
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Affiliation(s)
- Priyanka L Singh
- Department of Neurological Surgery, UMDNJ - New Jersey Medical School, Newark, NJ 07101-1709, USA ; Reynolds Family Spine Laboratory, Newark, NJ 07101-1709, USA
| | - Nitin Agarwal
- Department of Neurological Surgery, UMDNJ - New Jersey Medical School, Newark, NJ 07101-1709, USA ; Reynolds Family Spine Laboratory, Newark, NJ 07101-1709, USA
| | - James C Barrese
- Department of Neurological Surgery, UMDNJ - New Jersey Medical School, Newark, NJ 07101-1709, USA
| | - Robert F Heary
- Department of Neurological Surgery, UMDNJ - New Jersey Medical School, Newark, NJ 07101-1709, USA ; Reynolds Family Spine Laboratory, Newark, NJ 07101-1709, USA
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22
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Boomkamp SD, McGrath MA, Houslay MD, Barnett SC. Epac and the high affinity rolipram binding conformer of PDE4 modulate neurite outgrowth and myelination using an in vitro spinal cord injury model. Br J Pharmacol 2014; 171:2385-98. [PMID: 24467222 PMCID: PMC3997278 DOI: 10.1111/bph.12588] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Revised: 12/23/2013] [Accepted: 01/15/2014] [Indexed: 01/08/2023] Open
Abstract
Background and Purpose cAMP and pharmacological inhibition of PDE4, which degrades it, are promising therapeutic targets for the treatment of spinal cord injury (SCI). Using our previously described in vitro SCI model, we studied the mechanisms by which cAMP modulators promote neurite outgrowth and myelination using enantiomers of the PDE4-specific inhibitor rolipram and other modulators of downstream signalling effectors. Experimental Approach Rat mixed neural cell myelinating cultures were cut with a scalpel and treated with enantiomers of the PDE4-specific inhibitor rolipram, Epac agonists and PKA antagonists. Neurite outgrowth, density and myelination were assessed by immunocytochemistry and cytokine levels analysed by qPCR. Key Results Inhibition of the high-affinity rolipram-binding state (HARBS), rather than the low-affinity rolipram binding state (LARBS) PDE4 conformer promoted neurite outgrowth and myelination. These effects were mediated through the activation of Epac and not through PKA. Expression of the chemokine CXCL10, known to inhibit myelination, was markedly elevated in astrocytes after Rho inhibition and this was blocked by inhibition of Rho kinase or PDE4. Conclusions and Implications PDE4 inhibitors targeted at the HARBS conformer or Epac agonists may provide promising novel targets for the treatment of SCI. Our study demonstrates the differential mechanisms of action of these compounds, as well as the benefit of a combined pharmacological approach and highlighting potential promising targets for the treatment of SCI. These findings need to be confirmed in vivo.
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Affiliation(s)
- S D Boomkamp
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
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23
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Zygmunt M, Chłoń-Rzepa G, Sapa J. Analgesic and anti-inflammatory activity of 7-substituted purine-2,6-diones. Pharmacol Rep 2014; 66:996-1002. [PMID: 25443727 DOI: 10.1016/j.pharep.2014.06.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 06/09/2014] [Accepted: 06/13/2014] [Indexed: 12/31/2022]
Abstract
BACKGROUND In an effort to develop new analgesic and anti-inflammatory agents, we determined a series of 7-substituted purine-2,6-diones. METHODS The obtained compounds (1-6) were evaluated pharmacologically in four in vivo models: the writhing syndrome, the formalin tests, the carrageenan-induced edema model and the zymosan-induced peritonitis. The influence of the investigated compounds on the phosphodiesterase (PDE) and PDE4B activity was also determined. In addition, determination of the antioxidant activity was determined by the FRAP assay. RESULTS A majority of the tested compounds showed a significant analgesic and anti-inflammatory activity. The strongest analgesic and anti-inflammatory effect was observed for 1 and 2. The active compound 1 was more efficient than theophylline in inhibiting the PDE and more efficient than rolipram in inhibiting the PDE4B activity. The tested compounds did not show significant antioxidant properties. CONCLUSION Active compounds (1-6) inhibited the PDE activity, while compound 1 significantly inhibited the PDE4B activity, what may suggest that this mechanism may be involved in their analgesic/anti-inflammatory properties.
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Affiliation(s)
- Małgorzata Zygmunt
- Department of Pharmacological Screening, Chair of Pharmacodynamics, Jagiellonian University, Medical College, Kraków, Poland.
| | - Grażyna Chłoń-Rzepa
- Department of Medicinal Chemistry, Jagiellonian University, Medical College, Kraków, Poland
| | - Jacek Sapa
- Department of Pharmacological Screening, Chair of Pharmacodynamics, Jagiellonian University, Medical College, Kraków, Poland
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Liao J, Xie J, Lin D, Lu N, Guo L, Li W, Pu B, Yang Y, Yang Z, Zhang Y, Song Y. Meglumine cyclic adenylate improves neurological function following acute spinal cord injury in rats. Mol Med Rep 2014; 10:1225-30. [PMID: 24970286 DOI: 10.3892/mmr.2014.2352] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Accepted: 05/14/2014] [Indexed: 02/05/2023] Open
Abstract
Elevation of intracellular cyclic adenosine monophosphate (cAMP) levels facilitates recovery following spinal injury by suppressing secondary pathology and promoting axonal regeneration. However, this treatment strategy is limited by lack of effective and tolerable clinical agents. The present study examined the effects of meglumine cyclic adenylate (MCA) on neurological recovery, cAMP concentration, adenylate cyclase 3 (AC3) activity and phosphodiesterase 4D (PDE4D) activity during early stage acute spinal cord injury (SCI) in rats. A total of 48 Sprague‑Dawley rats were randomly assigned to groups A, B or C, each consisting of 16 animals. SCI was induced by Allen's method using a 7 g x 3 cm extradural weight‑drop impact on spinal cord segment T11. A total of 30 min following SCI, group A received a single 30 mg/kg‑bw i.p. dose of methylprednisolone, group B received 2 mg/kg‑bw i.p. MCA daily for seven days and group C were administered an equal volume of normal saline. Seven days following SCI, the spinal cord samples from eight rats per group were obtained to measure the cAMP concentration, and the activities of AC3 and PDE4D. The remaining eight rats per group were used for behavioral assessments using the inclined plane stability test and Gale scale for up to six weeks post‑SCI. The drug‑treated groups A and B had higher cAMP concentrations and AC3 activities but lower PDE4D activities at the lesion sites, as well as superior behavioral scores post‑SCI compared with the vehicle‑treated group C (P<0.05). Furthermore, cAMP was higher in group B than in group A (P<0.05). It was concluded that MCA may serve as an effective SCI treatment by activating AC3 and suppressing PDE4D.
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Affiliation(s)
- Jingwu Liao
- Department of Orthopaedic Surgery, The 2nd Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650031, P.R. China
| | - Jingming Xie
- Department of Orthopaedic Surgery, The 2nd Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650031, P.R. China
| | - Daqiang Lin
- Department of Orthopaedic Surgery, Hospital of Integrated Traditional and Western Medicine, Dazhou, Sichuan 635000, P.R. China
| | - Ning Lu
- Department of Orthopaedic Surgery, The 2nd Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650031, P.R. China
| | - Limin Guo
- Department of Orthopaedic Surgery, The 2nd Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650031, P.R. China
| | - Weiqiang Li
- Department of Orthopaedic Surgery, The 2nd Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650031, P.R. China
| | - Bo Pu
- Department of Orthopaedic Surgery, The 2nd Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650031, P.R. China
| | - Yang Yang
- Department of Orthopaedic Surgery, The 2nd Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650031, P.R. China
| | - Zhenlong Yang
- Department of Orthopaedic Surgery, The 2nd Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650031, P.R. China
| | - Ying Zhang
- Department of Orthopaedic Surgery, The 2nd Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650031, P.R. China
| | - Yueming Song
- Department of Orthopaedic Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
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Walker CL, Xu XM. PTEN inhibitor bisperoxovanadium protects oligodendrocytes and myelin and prevents neuronal atrophy in adult rats following cervical hemicontusive spinal cord injury. Neurosci Lett 2014; 573:64-8. [PMID: 24582904 DOI: 10.1016/j.neulet.2014.02.039] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Revised: 02/13/2014] [Accepted: 02/15/2014] [Indexed: 12/21/2022]
Abstract
Cervical spinal cord injury (SCI) damages axons and motor neurons responsible for ipsilateral forelimb function and causes demyelination and oligodendrocyte death. Inhibition of the phosphatase and tensin homologue, PTEN, promotes neural cell survival, neuroprotection and regeneration in vivo and in vitro. PTEN inhibition can also promote oligodendrocyte-mediated myelination of axons in vitro likely through Akt activation. We recently demonstrated that acute treatment with phosphatase PTEN inhibitor, bisperoxovanadium (bpV)-pic reduced tissue damage, neuron death, and promoted functional recovery after cervical hemi-contusion SCI. Evidence suggests bpV can promote myelin stability; however, bpV effects on myelination and oligodendrocytes in contusive SCI models are unclear. We hypothesized that bpV could increase myelin around the injury site through sparing or remyelination, and that bpV treatment may promote increased numbers of oligodendrocytes. Using histological and immunofluorescence labeling, we found that bpV treatment promoted significant spared white matter (30%; p<0.01) and relative Luxol Fast Blue (LFB)(+) myelin area rostral (Veh: 0.56 ± 0.01 vs. bpV: 0.64 ± 0.02; p<0.05) and at the epicenter (Veh: 0.42 ± 0.03 vs. bpV: 0.54 ± 0.03; p<0.05). VLF oligodendrocytes were also significantly greater with bpV therapy (109 ± 5.3 vs. Veh: 77 ± 2.7 mm(-2); p<0.01). In addition, bpV increased mean motor neuron soma area versus vehicle-treatment (1.0 ± 0.02 vs. Veh: 0.77 ± 0.02) relative to Sham neuron size. This study provides key insight into additional cell and tissue effects that could contribute to bpV-mediated functional recovery observed after contusive cervical SCI.
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Affiliation(s)
- Chandler L Walker
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Department of Neurological Surgery, Indiana University School of Medicine, 950 W. Walnut Street, R2 Building, Room 402, Indianapolis, IN 46202, USA; Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Department of Anatomy and Cell Biology, Indiana University School of Medicine, 950 W. Walnut Street, R2 Building, Room 402, Indianapolis, IN 46202, USA.
| | - Xiao-Ming Xu
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Department of Neurological Surgery, Indiana University School of Medicine, 950 W. Walnut Street, R2 Building, Room 402, Indianapolis, IN 46202, USA; Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Department of Anatomy and Cell Biology, Indiana University School of Medicine, 950 W. Walnut Street, R2 Building, Room 402, Indianapolis, IN 46202, USA.
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26
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Silva NA, Sousa N, Reis RL, Salgado AJ. From basics to clinical: a comprehensive review on spinal cord injury. Prog Neurobiol 2013; 114:25-57. [PMID: 24269804 DOI: 10.1016/j.pneurobio.2013.11.002] [Citation(s) in RCA: 526] [Impact Index Per Article: 47.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 11/12/2013] [Accepted: 11/12/2013] [Indexed: 12/15/2022]
Abstract
Spinal cord injury (SCI) is a devastating neurological disorder that affects thousands of individuals each year. Over the past decades an enormous progress has been made in our understanding of the molecular and cellular events generated by SCI, providing insights into crucial mechanisms that contribute to tissue damage and regenerative failure of injured neurons. Current treatment options for SCI include the use of high dose methylprednisolone, surgical interventions to stabilize and decompress the spinal cord, and rehabilitative care. Nonetheless, SCI is still a harmful condition for which there is yet no cure. Cellular, molecular, rehabilitative training and combinatorial therapies have shown promising results in animal models. Nevertheless, work remains to be done to ascertain whether any of these therapies can safely improve patient's condition after human SCI. This review provides an extensive overview of SCI research, as well as its clinical component. It starts covering areas from physiology and anatomy of the spinal cord, neuropathology of the SCI, current clinical options, neuronal plasticity after SCI, animal models and techniques to assess recovery, focusing the subsequent discussion on a variety of promising neuroprotective, cell-based and combinatorial therapeutic approaches that have recently moved, or are close, to clinical testing.
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Affiliation(s)
- Nuno A Silva
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Nuno Sousa
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Rui L Reis
- ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal; 3B's Research Group - Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, 4806-909 Caldas das Taipas, Guimarães, Portugal
| | - António J Salgado
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal.
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27
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Syed YA, Baer A, Hofer MP, González GA, Rundle J, Myrta S, Huang JK, Zhao C, Rossner MJ, Trotter MWB, Lubec G, Franklin RJM, Kotter MR. Inhibition of phosphodiesterase-4 promotes oligodendrocyte precursor cell differentiation and enhances CNS remyelination. EMBO Mol Med 2013; 5:1918-34. [PMID: 24293318 PMCID: PMC3914530 DOI: 10.1002/emmm.201303123] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Revised: 09/12/2013] [Accepted: 09/18/2013] [Indexed: 01/25/2023] Open
Abstract
The increasing effectiveness of new disease-modifying drugs that suppress disease activity in multiple sclerosis has opened up opportunities for regenerative medicines that enhance remyelination and potentially slow disease progression. Although several new targets for therapeutic enhancement of remyelination have emerged, few lend themselves readily to conventional drug development. Here, we used transcription profiling to identify mitogen-activated protein kinase (Mapk) signalling as an important regulator involved in the differentiation of oligodendrocyte progenitor cells (OPCs) into oligodendrocytes. We show in tissue culture that activation of Mapk signalling by elevation of intracellular levels of cyclic adenosine monophosphate (cAMP) using administration of either dibutyryl-cAMP or inhibitors of the cAMP-hydrolysing enzyme phosphodiesterase-4 (Pde4) enhances OPC differentiation. Finally, we demonstrate that systemic delivery of a Pde4 inhibitor leads to enhanced differentiation of OPCs within focal areas of toxin-induced demyelination and a consequent acceleration of remyelination. These data reveal a novel approach to therapeutic enhancement of remyelination amenable to pharmacological intervention and hence with significant potential for translation.
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Affiliation(s)
- Yasir A Syed
- Wellcome Trust and MRC Cambridge Stem Cell Institute, and Anne McLaren Laboratory for Regenerative Medicine, University of Cambridge, West Forvie Building, Forvie Site, Robinson Way, Cambridge, UK; Department of Neurosurgery, Medical University Vienna, Vienna, Austria; Max-Planck Institute for Experimental Medicine, Department of Neurogenetics, Goettingen, Germany
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28
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Cyclic AMP promotes axon regeneration, lesion repair and neuronal survival in lampreys after spinal cord injury. Exp Neurol 2013; 250:31-42. [PMID: 24041988 DOI: 10.1016/j.expneurol.2013.09.004] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Revised: 09/03/2013] [Accepted: 09/08/2013] [Indexed: 01/10/2023]
Abstract
Axon regeneration after spinal cord injury in mammals is inadequate to restore function, illustrating the need to design better strategies for improving outcomes. Increasing the levels of the second messenger cyclic adenosine monophosphate (cAMP) after spinal cord injury enhances axon regeneration across a wide variety of species, making it an excellent candidate molecule that has therapeutic potential. However, several important aspects of the cellular and molecular mechanisms by which cAMP enhances axon regeneration are still unclear, such as how cAMP affects axon growth patterns, the molecular components within growing axon tips, the lesion scar, and neuronal survival. To address these points, we took advantage of the large, identified reticulospinal (RS) neurons in lamprey, a vertebrate that exhibits robust axon regeneration after a complete spinal cord transection. Application of a cAMP analog, db-cAMP, at the time of spinal cord transection increased the number of axons that regenerated across the lesion site. Db-cAMP also promoted axons to regenerate in straighter paths, prevented abnormal axonal growth patterns, increased the levels of synaptotagmin within axon tips, and increased the number of axotomized neurons that survived after spinal cord injury, thereby increasing the pool of neurons available for regeneration. There was also a transient increase in the number of microglia/macrophages and improved repair of the lesion site. Taken together, these data reveal several new features of the cellular and molecular mechanisms underlying cAMP-mediated enhancement of axon regeneration, further emphasizing the positive roles for this conserved pathway.
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29
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Medina-Rodríguez EM, Arenzana FJ, Pastor J, Redondo M, Palomo V, García de Sola R, Gil C, Martínez A, Bribián A, de Castro F. Inhibition of endogenous phosphodiesterase 7 promotes oligodendrocyte precursor differentiation and survival. Cell Mol Life Sci 2013; 70:3449-62. [PMID: 23661015 PMCID: PMC11113628 DOI: 10.1007/s00018-013-1340-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Revised: 04/05/2013] [Accepted: 04/08/2013] [Indexed: 12/21/2022]
Abstract
During the development of the central nervous system (CNS), oligodendrocyte precursors (OPCs) are generated in specific sites within the neural tube and then migrate to colonize the entire CNS, where they differentiate into myelin-forming oligodendrocytes. Demyelinating diseases such as multiple sclerosis (MS) are characterized by the death of these cells. The CNS reacts to demyelination and by promoting spontaneous remyelination, an effect mediated by endogenous OPCs, cells that represent approximately 5-7 % of the cells in the adult brain. Numerous factors influence oligodendrogliogenesis and oligodendrocyte differentiation, including morphogens, growth factors, chemotropic molecules, extracellular matrix proteins, and intracellular cAMP levels. Here, we show that during development and in early adulthood, OPCs in the murine cerebral cortex contain phosphodiesterase-7 (PDE7) that metabolizes cAMP. We investigated the effects of different PDE7 inhibitors (the well-known BRL-50481 and two new ones, TC3.6 and VP1.15) on OPC proliferation, survival, and differentiation. While none of the PDE7 inhibitors analyzed altered OPC proliferation, TC3.6 and VP1.15 enhanced OPC survival and differentiation, processes in which ERK intracellular signaling played a key role. PDE7 expression was also observed in OPCs isolated from adult human brains and the differentiation of these OPCs into more mature oligodendroglial phenotypes was accelerated by treatment with both new PDE7 inhibitors. These findings reveal new roles for PDE7 in regulating OPC survival and differentiation during brain development and in adulthood, and they may further our understanding of myelination and facilitate the development of therapeutic remyelination strategies for the treatment of MS.
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Affiliation(s)
- E. M. Medina-Rodríguez
- Grupo de Neurobiología del Desarrollo-GNDe, Hospital Nacional de Parapléjicos, Finca “La Peraleda”, s/n, 45071 Toledo, Spain
| | - F. J. Arenzana
- Grupo de Neurobiología del Desarrollo-GNDe, Hospital Nacional de Parapléjicos, Finca “La Peraleda”, s/n, 45071 Toledo, Spain
| | - J. Pastor
- Neurofisiología Clínica, Hospital Universitario La Princesa, Madrid, Spain
| | - M. Redondo
- Instituto de Química Médica, CSIC, Juan de la Cierva, Madrid, Spain
| | - V. Palomo
- Instituto de Química Médica, CSIC, Juan de la Cierva, Madrid, Spain
| | | | - C. Gil
- Instituto de Química Médica, CSIC, Juan de la Cierva, Madrid, Spain
| | - A. Martínez
- Instituto de Química Médica, CSIC, Juan de la Cierva, Madrid, Spain
| | - A. Bribián
- Grupo de Neurobiología del Desarrollo-GNDe, Hospital Nacional de Parapléjicos, Finca “La Peraleda”, s/n, 45071 Toledo, Spain
- Institute of Bioengineering of Catalonia, Parc Cientific de Barcelona & Cell Biology Department, Universidad de Barcelona, Barcelona, Spain
| | - F. de Castro
- Grupo de Neurobiología del Desarrollo-GNDe, Hospital Nacional de Parapléjicos, Finca “La Peraleda”, s/n, 45071 Toledo, Spain
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The phosphodiesterase-4 inhibitor rolipram protects from ischemic stroke in mice by reducing blood–brain-barrier damage, inflammation and thrombosis. Exp Neurol 2013; 247:80-90. [DOI: 10.1016/j.expneurol.2013.03.026] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Revised: 03/27/2013] [Accepted: 03/29/2013] [Indexed: 01/06/2023]
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Costa LM, Pereira JE, Filipe VM, Magalhães LG, Couto PA, Gonzalo-Orden JM, Raimondo S, Geuna S, Maurício AC, Nikulina E, Filbin MT, Varejão AS. Rolipram promotes functional recovery after contusive thoracic spinal cord injury in rats. Behav Brain Res 2013; 243:66-73. [DOI: 10.1016/j.bbr.2012.12.056] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2012] [Revised: 12/24/2012] [Accepted: 12/29/2012] [Indexed: 01/28/2023]
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Etazolate, an α-secretase activator, reduces neuroinflammation and offers persistent neuroprotection following traumatic brain injury in mice. Neuropharmacology 2013. [DOI: 10.1016/j.neuropharm.2012.11.009] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Yin Y, Sun W, Li Z, Zhang B, Cui H, Deng L, Xie P, Xiang J, Zou J. Effects of combining methylprednisolone with rolipram on functional recovery in adult rats following spinal cord injury. Neurochem Int 2013; 62:903-12. [PMID: 23499793 DOI: 10.1016/j.neuint.2013.03.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Revised: 02/05/2013] [Accepted: 03/05/2013] [Indexed: 12/20/2022]
Abstract
Methylprednisolone (MP) has been widely used as a standard therapeutic agent for the treatment of spinal cord injury (SCI). Because of its controversial beneficial effects, the combination of MP and other pharmacological agents aimed at enhancing functional recovery is desirable. The phosphodiesterase 4 (PDE4) inhibitor rolipram has been implicated in promotion of regeneration due to elevating cAMP. In the present study, we sought to determine the effects of MP and rolipram, administered in combination, after spinal cord injury (SCI) in adult rats. Here we show that in vitro administration of rolipram and MP significantly increased neuron survival and promoted neurite outgrowth of neurons on the inhibitory substrate CSPGs by upregulation of MMP-2 expression; in vivo administration of rolipram and MP inhibited CSPG expression and increase CSPG digestion after rat SCI. Rolipram and MP combining treatment promoted significant neuroprotection through reduced motoneuron death, minimized lesion cavity, and increased regeneration of lesioned corticospinal tract (CST) axons beyond the lesion site after SCI. Enhanced functional recovery was also observed. Overall, our study strongly suggested that the combination treatment of MP and rolipram may represent a promising strategy for clinically applicable pharmacological therapy for rapid initiation of neuroprotection after SCI.
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Affiliation(s)
- Ying Yin
- Department of Clinical Laboratory Science, Wuxi People's Hospital of Nanjing Medical University, Wuxi, PR China
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Schaal SM, Garg MS, Ghosh M, Lovera L, Lopez M, Patel M, Louro J, Patel S, Tuesta L, Chan WM, Pearse DD. The therapeutic profile of rolipram, PDE target and mechanism of action as a neuroprotectant following spinal cord injury. PLoS One 2012; 7:e43634. [PMID: 23028463 PMCID: PMC3446989 DOI: 10.1371/journal.pone.0043634] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Accepted: 07/24/2012] [Indexed: 01/08/2023] Open
Abstract
The extent of damage following spinal cord injury (SCI) can be reduced by various neuroprotective regimens that include maintaining levels of cyclic adenosine monophosphate (cyclic AMP), via administration of the phosphodiesterase 4 (PDE4) inhibitor Rolipram. The current study sought to determine the optimal neuroprotective dose, route and therapeutic window for Rolipram following contusive SCI in rat as well as its prominent PDE target and putative mechanism of protection. Rolipram or vehicle control (10% ethanol) was given subcutaneously (s.c.) daily for 2 wk post-injury (PI) after which the preservation of oligodendrocytes, neurons and central myelinated axons was stereologically assessed. Doses of 0.1 mg/kg to 1.0 mg/kg (given at 1 h PI) increased neuronal survival; 0.5 mg to 1.0 mg/kg protected oligodendrocytes and 1.0 mg/kg produced optimal preservation of central myelinated axons. Ethanol also demonstrated significant neuronal and oligo-protection; though the preservation provided was significantly less than Rolipram. Subsequent use of this optimal Rolipram dose, 1.0 mg/kg, via different routes (i.v., s.c. or oral, 1 h PI), demonstrated that i.v. administration produced the most significant and consistent cyto- and axo- protection, although all routes were effective. Examination of the therapeutic window for i.v. Rolipram (1.0 mg/kg), when initiated between 1 and 48 h after SCI, revealed maximal neuroprotection at 2 h post-SCI, although the protective efficacy of Rolipram could still be observed when administration was delayed for up to 48 h PI. Importantly, use of the optimal Rolipram regimen significantly improved locomotor function after SCI as measured by the BBB score. Lastly we show SCI-induced changes in PDE4A, B and D expression and phosphorylation as well as cytokine expression and immune cell infiltration. We demonstrate that Rolipram abrogates SCI-induced PDE4B1 and PDE4A5 production, PDE4A5 phosphorylation, MCP-1 expression and immune cell infiltration, while preventing post-injury reductions in IL-10. This work supports the use of Rolipram as an acute neuroprotectant following SCI and defines an optimal administration protocol and target for its therapeutic application.
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Affiliation(s)
- Sandra Marie Schaal
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida, United States of America
- The Neuroscience Program, University of Miami, Miami, Florida, United States of America
| | - Maneesh Sen Garg
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Mousumi Ghosh
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Lilie Lovera
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Michael Lopez
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Monal Patel
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Jack Louro
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Samik Patel
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Luis Tuesta
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Wai-Man Chan
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Damien Daniel Pearse
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida, United States of America
- The Neuroscience Program, University of Miami, Miami, Florida, United States of America
- The Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, Florida, United States of America
- The Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, Florida, United States of America
- * E-mail:
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Ghosh M, Garcia-Castillo D, Aguirre V, Golshani R, Atkins CM, Bramlett HM, Dietrich WD, Pearse DD. Proinflammatory cytokine regulation of cyclic AMP-phosphodiesterase 4 signaling in microglia in vitro and following CNS injury. Glia 2012; 60:1839-59. [PMID: 22865690 DOI: 10.1002/glia.22401] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2011] [Accepted: 07/09/2012] [Indexed: 01/15/2023]
Abstract
Cyclic AMP suppresses immune cell activation and inflammation. The positive feedback loop of proinflammatory cytokine production and immune activation implies that cytokines may not only be regulated by cyclic AMP but also conversely regulate cyclic AMP. This study examined the effects of tumor necrosis factor (TNF)-α and interleukin (IL)-1β on cyclic AMP-phosphodiesterase (PDE) signaling in microglia in vitro and after spinal cord injury (SCI) or traumatic brain injury (TBI). TNF-α or IL-1β stimulation produced a profound reduction (>90%) of cyclic AMP within EOC2 microglia from 30 min that then recovered after IL-1β but remained suppressed with TNF-α through 24 h. Cyclic AMP was also reduced in TNF-α-stimulated primary microglia, albeit to a lesser extent. Accompanying TNF-α-induced cyclic AMP reductions, but not IL-1β, was increased cyclic AMP-PDE activity. The role of PDE4 activity in cyclic AMP reductions was confirmed by using Rolipram. Examination of pde4 mRNA revealed an immediate, persistent increase in pde4b with TNF-α; IL-1β increased all pde4 mRNAs. Immunoblotting for PDE4 showed that both cytokines increased PDE4A1, but only TNF-α increased PDE4B2. Immunocytochemistry revealed PDE4B nuclear translocation with TNF-α but not IL-1β. Acutely after SCI/TBI, where cyclic AMP levels are reduced, PDE4B was localized to activated OX-42(+) microglia; PDE4B was absent in OX-42(+) cells in uninjured spinal cord/cortex or inactive microglia. Immunoblotting showed PDE4B2 up-regulation from 24 h to 1 wk post-SCI, the peak of microglia activation. These studies show that TNF-α and IL-1β differentially affect cyclic AMP-PDE signaling in microglia. Targeting PDE4B2 may be a putative therapeutic direction for reducing microglia activation in CNS injury and neurodegenerative diseases.
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Affiliation(s)
- Mousumi Ghosh
- The Miami Project to Cure Paralysis, The University of Miami Miller School of Medicine, Miami, Florida 33101, USA
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Rolipram promotes remyelination possibly via MEK-ERK signal pathway in cuprizone-induced demyelination mouse. Exp Neurol 2012; 237:304-11. [PMID: 22836144 DOI: 10.1016/j.expneurol.2012.07.011] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Revised: 07/16/2012] [Accepted: 07/18/2012] [Indexed: 12/15/2022]
Abstract
OBJECTIVE Rolipram, a 3'-5'-cyclic adenosine monophosphate (cAMP)-dependent phosphodiesterase 4 (PDE4) inhibitor, has long been studied for its immune modulating effects in the treatment of experimental autoimmune encephalomyelitis (EAE). In the current study, we investigated the effects of rolipram on remyelination after cuprizone- or lysolecithin-induced demyelination and the signal transduction pathways potentially modulating this response. MATERIALS AND METHODS Cuprizone-induced demyelination in mice and lysolecithin (LPC)-induced demyelination in rat cerebellum slice culture were treated with rolipram. Demyelination was evaluated by Luxol fast blue (LFB) or myelin basic protein (MBP) staining and western blot. Oligodendroglial cells were cultured with different concentrations of rolipram, and 2', 3'-cyclic nucleotide phosphodiesterase (CNPase) activity, MBP expression, and extracellular signal-regulated kinase (ERK) phosphorylation were measured. RESULTS Rolipram antagonized lysolecithin (LPC)-induced demyelination in rat cerebellar slice cultures and cuprizone-fed mice. In vitro, rolipram treatment promoted oligodendrocyte precursor cell (OPC) maturation, an effect that was partially blocked by the inhibitors of the mitogen activated protein kinase kinase (MEK). CONCLUSION Rolipram promotes the maturation of OPCs, facilitates remyelination, and increases ERK phosphorylation. All of these actions are involved in an action against cuprizone-induced demyelination that may occur partly via the MEK-ERK pathway. Importantly, this may have therapeutic implications for MS.
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Drug-eluting microfibrous patches for the local delivery of rolipram in spinal cord repair. J Control Release 2012; 161:910-7. [PMID: 22634093 DOI: 10.1016/j.jconrel.2012.05.034] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2012] [Revised: 05/03/2012] [Accepted: 05/16/2012] [Indexed: 01/10/2023]
Abstract
Spinal cord injury (SCI) remains a major challenge for regenerative medicine. Following SCI, axon growth inhibitors and other inflammatory responses prevent functional recovery. Previous studies have demonstrated that rolipram, an anti-inflammatory and cyclic adenosine monophosphate preserving small molecule, improves spinal cord regeneration when delivered systemically. However, more recent studies showed that rolipram has some adverse effects in spinal cord repair. Here, we developed a drug-delivery platform for the local delivery of rolipram into the spinal cord. The potential of drug-eluting microfibrous patches for continuous delivery of high and low-dose rolipram concentrations was characterized in vitro. Following C5 hemisections, athymic rats were treated with patches loaded with low and high doses of rolipram. In general, animals treated with low-dose rolipram experienced greater functional and anatomical recovery relative to all other groups. Outcomes from the high-dose rolipram treatment were similar to those with no treatment. In addition, high-dose treated animals experienced reduced survival rates suggesting that systemic toxicity was reached. With the ability to control the release of drug dosage locally within the spinal cord, drug-eluting microfibrous patches demonstrate the importance of appropriate local release-kinetics of rolipram, proving their usefulness as a therapeutic platform for the study and repair of SCI.
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Meyer H, Stöver T, Fouchet F, Bastiat G, Saulnier P, Bäumer W, Lenarz T, Scheper V. Lipidic nanocapsule drug delivery: neuronal protection for cochlear implant optimization. Int J Nanomedicine 2012; 7:2449-64. [PMID: 22654517 PMCID: PMC3363950 DOI: 10.2147/ijn.s29712] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Objective Sensorineural hearing loss leads to the progressive degeneration of spiral ganglion cells (SGC). Next to postoperative fibrous tissue growth, which should be suppressed to assure a close nerve–electrode interaction, the density of healthy SGC is one factor that influences the efficiency of cochlear implants (CI), the choice of treatment for affected patients. Rolipram, a phosphodiesterase-4 inhibitor, has proven neuroprotective and anti-inflammatory effects and might also reduce SGC degeneration and fibrosis, but it has to pass the cellular membrane to be biologically active. Methods Lipidic nanocapsules (LNC) can be used as biodegradable drug carriers to increase the efficacy of conventional application methods. We examined the biological effects of rolipram and LNC’s core encapsulated rolipram on SGC and dendritic cell (DC) tumor necrosis factor-α (TNF-α) production in vitro and on SGC survival in systemically-deafened guinea pigs in vivo. Results Our results prove that rolipram does not have a beneficial effect on cultured SGC. Incorporation of rolipram in LNC increased the survival of SGC significantly. In the DC study, rolipram significantly inhibited TNF-α in a dose-dependent manner. The rolipram-loaded LNC provided a significant cytokine inhibition as well. In vivo data do not confirm the in vitro results. Conclusion By transporting rolipram into the SGC cytoplasm, LNC enabled the neuroprotective effect of rolipram in vitro, but not in vivo. This might be due to dilution of test substances by perilymph or an inadequate release of rolipram based on differing in vivo and in vitro conditions. Nevertheless, based on in vitro results, proving a significantly increased neuronal survival when using LNC-rolipram compared to pure rolipram and pure LNC application, we believe that the combination of rolipram and LNC can potentially reduce neuronal degeneration and fibrosis after CI implantation. We conclude that rolipram is a promising drug that can be used in inner ear therapy and that LNC have potential as an inner ear drug-delivery system. Further experiments with modified conditions might reveal in vivo biological effects.
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Affiliation(s)
- Hartwig Meyer
- Department of Otolaryngology, Hannover Medical School, University of Veterinary Medicine Hannover, Germany
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Atkins CM, Kang Y, Furones C, Truettner JS, Alonso OF, Dietrich WD. Postinjury treatment with rolipram increases hemorrhage after traumatic brain injury. J Neurosci Res 2012; 90:1861-71. [PMID: 22535545 DOI: 10.1002/jnr.23069] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Revised: 03/01/2012] [Accepted: 03/22/2012] [Indexed: 11/11/2022]
Abstract
The pathology caused by traumatic brain injury (TBI) is exacerbated by the inflammatory response of the injured brain. Two proinflammatory cytokines that contribute to inflammation after TBI are tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β). From previous studies using the parasagittal fluid-percussion brain injury model, we reported that the anti-inflammatory drug rolipram, a phosphodiesterase 4 inhibitor, reduced TNF-α and IL-1β levels and improved histopathological outcome when administered 30 min prior to injury. We now report that treatment with (±)-rolipram given 30 min after injury significantly reduced TNF-α levels in the cortex and hippocampus. However, postinjury administration of (±)-rolipram significantly increased cortical contusion volume and increased atrophy of the cortex compared with vehicle-treated animals at 10 days postinjury. Thus, despite the reduction in proinflammatory cytokine levels, histopathological outcome was worsened with post-TBI (±)-rolipram treatment. Further histological analysis of (±)-rolipram-treated TBI animals revealed significant hemorrhage in the contused brain. Given the well-known role of (±)-rolipram of increasing vasodilation, it is likely that (±)-rolipram worsened outcome after fluid-percussion brain injury by causing increased bleeding.
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Affiliation(s)
- C M Atkins
- The Miami Project to Cure Paralysis, Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, Florida, USA.
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Insel PA, Zhang L, Murray F, Yokouchi H, Zambon AC. Cyclic AMP is both a pro-apoptotic and anti-apoptotic second messenger. Acta Physiol (Oxf) 2012; 204:277-87. [PMID: 21385327 DOI: 10.1111/j.1748-1716.2011.02273.x] [Citation(s) in RCA: 165] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The second messenger cyclic AMP (cAMP) can either stimulate or inhibit programmed cell death (apoptosis). Here, we review examples of cell types that show pro-apoptotic or anti-apoptotic responses to increases in cAMP. We also show that cells can have both such responses, although predominantly having one or the other. Protein kinase A (PKA)-promoted changes in phosphorylation and gene expression can mediate pro-apoptotic responses, such as in murine S49 lymphoma cells, based on evidence that mutants lacking PKA fail to undergo cAMP-promoted, mitochondria-dependent apoptosis. Mechanisms for the anti-apoptotic response to cAMP likely involve Epac (Exchange protein activated by cAMP), a cAMP-regulated effector that is a guanine nucleotide exchange factor (GEF) for the low molecular weight G-protein, Rap1. Therapeutic approaches that activate PKA-mediated pro-apoptosis or block Epac-mediated anti-apoptotisis may provide a means to enhance cell killing, such as in certain cancers. In contrast, efforts to block PKA or stimulate Epac have the potential to be useful in diseases settings (such as heart failure) associated with cAMP-promoted apoptosis.
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Affiliation(s)
- P A Insel
- Department of Pharmacology, University of California, San Diego, La Jolla, 92093-0636, USA.
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Mekhail M, Almazan G, Tabrizian M. Oligodendrocyte-protection and remyelination post-spinal cord injuries: a review. Prog Neurobiol 2012; 96:322-39. [PMID: 22307058 DOI: 10.1016/j.pneurobio.2012.01.008] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2011] [Revised: 01/09/2012] [Accepted: 01/19/2012] [Indexed: 12/28/2022]
Abstract
In the past four decades, the main focus of investigators in the field of spinal cord regeneration has been to devise therapeutic measures that enhance neural regeneration. More recently, emphasis has been placed on enhancing remyelination and providing oligodendrocyte-protection after a spinal cord injury (SCI). Demyelination post-SCI is part of the cascading secondary injury that takes place immediately after the primary insult; therefore, therapeutic measures are needed to reduce oligodendrocyte death and/or enhance remyelination during the acute stage, preserving neurological functions that would be lost otherwise. In this review a thorough investigation of the oligodendrocyte-protective and remyelinative molecular therapies available to date is provided. The advent of new biomaterials shown to promote remyelination post-SCI is discussed mainly in the context of a combinatorial approach where the biomaterial also provides drug delivery capabilities. The aim of these molecular and biomaterial-based therapies is twofold: (1) oligodendrocyte-protective therapy, which involves protecting already existing oligodendrocytes from undergoing apoptosis/necrosis; and (2) inductive remyelination, which involves harnessing the remyelinative capabilities of endogenous oligodendrocyte precursor cells (OPCs) at the lesion site by providing a suitable environment for their migration, survival, proliferation and differentiation. From the evidence reported in the literature, we conclude that the use of a combinatorial approach including biomaterials and molecular therapies would provide advantages such as: (1) sustained release of the therapeutic molecule, (2) local delivery at the lesion site, and (3) an environment at the site of injury that promotes OPC migration, differentiation and remyelination.
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Affiliation(s)
- Mina Mekhail
- Department of Biomedical Engineering, McGill University, Montreal, Quebec, Canada.
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Becker D, McDonald JW. Approaches to repairing the damaged spinal cord: overview. HANDBOOK OF CLINICAL NEUROLOGY 2012; 109:445-61. [PMID: 23098730 DOI: 10.1016/b978-0-444-52137-8.00028-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Affecting young people during the most productive period of their lives, spinal cord injury (SCI) is a devastating problem for modern society. In the past, treating SCI seemed frustrating and hopeless because of the tremendous morbidity and mortality, life-shattering impact, and limited therapeutic options associated with the condition. Today, however, an understanding of the underlying pathophysiological mechanisms, the development of neuroprotective interventions, and progress toward regenerative interventions are increasing hope for functional restoration. In this chapter, we provide an overview of various repair strategies for the injured spinal cord. Special attention will be paid to strategies that promote spontaneous regeneration, including functional electrical stimulation, cell replacement, neuroprotection, and remyelination. The concept that limited rebuilding can provide a disproportionate improvement in quality of life is emphasized throughout. New surgical procedures, pharmacological treatments, and functional neuromuscular stimulation methods have evolved over the last decades and can improve functional outcomes after spinal cord injury; however, limiting secondary injury remains the primary goal. Tissue replacement strategies, including the use of embryonic stem cells, become an important tool and can restore function in animal models. Controlled clinical trials are now required to confirm these observations. The ultimate goal is to harness the body's own potential to replace lost central nervous system cells by activation of endogenous progenitor cell repair mechanisms.
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Affiliation(s)
- Daniel Becker
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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Adderley SP, Thuet KM, Sridharan M, Bowles EA, Stephenson AH, Ellsworth ML, Sprague RS. Identification of cytosolic phosphodiesterases in the erythrocyte: a possible role for PDE5. Med Sci Monit 2011; 17:CR241-7. [PMID: 21525805 PMCID: PMC3366467 DOI: 10.12659/msm.881763] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Background Within erythrocytes (RBCs), cAMP levels are regulated by phosphodiesterases (PDEs). Increases in cAMP and ATP release associated with activation of β-adrenergic receptors (βARs) and prostacyclin receptors (IPRs) are regulated by PDEs 2, 4 and PDE 3, respectively. Here we establish the presence of cytosolic PDEs in RBCs and determine a role for PDE5 in regulating levels of cGMP. Material/Methods Purified cytosolic proteins were obtained from isolated human RBCs and western analysis was performed using antibodies against PDEs 3A, 4 and 5. Rabbit RBCs were incubated with dbcGMP, a cGMP analog, to determine the effect of cGMP on cAMP levels. To determine if cGMP affects receptor-mediated increases in cAMP, rabbit RBCs were incubated with dbcGMP prior to addition of isoproterenol (ISO), a βAR receptor agonist. To demonstrate that endogenous cGMP produces the same effect, rabbit and human RBCs were incubated with SpNONOate (SpNO), a nitric oxide donor, and YC1, a direct activator of soluble guanylyl cyclase (sGC), in the absence and presence of a selective PDE5 inhibitor, zaprinast (ZAP). Results Western analysis identified PDEs 3A, 4D and 5A. dbcGMP produced a concentration dependent increase in cAMP and ISO-induced increases in cAMP were potentiated by dbcGMP. In addition, incubation with YC1 and SpNO in the presence of ZAP potentiated βAR-induced increases in cAMP. Conclusions PDEs 2, 3A and 5 are present in the cytosol of human RBCs. PDE5 activity in RBCs regulates cGMP levels. Increases in intracellular cGMP augment cAMP levels. These studies suggest a novel role for PDE5 in erythrocytes.
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Affiliation(s)
- Shaquria P Adderley
- Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, St. Louis, MO, USA.
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Iannotti CA, Clark M, Horn KP, van Rooijen N, Silver J, Steinmetz MP. A combination immunomodulatory treatment promotes neuroprotection and locomotor recovery after contusion SCI. Exp Neurol 2011; 230:3-15. [DOI: 10.1016/j.expneurol.2010.03.010] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2009] [Revised: 03/04/2010] [Accepted: 03/10/2010] [Indexed: 10/19/2022]
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Effects of dibutyryl cyclic-AMP on survival and neuronal differentiation of neural stem/progenitor cells transplanted into spinal cord injured rats. PLoS One 2011; 6:e21744. [PMID: 21738784 PMCID: PMC3128087 DOI: 10.1371/journal.pone.0021744] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2011] [Accepted: 06/06/2011] [Indexed: 12/23/2022] Open
Abstract
Neural stem/progenitor cells (NSPCs) have great potential as a cell replacement therapy for spinal cord injury. However, poor control over transplant cell differentiation and survival remain major obstacles. In this study, we asked whether dibutyryl cyclic-AMP (dbcAMP), which was shown to induce up to 85% in vitro differentiation of NSPCs into neurons would enhance survival of transplanted NSPCs through prolonged exposure either in vitro or in vivo through the controlled release of dbcAMP encapsulated within poly(lactic-co-glycolic acid) (PLGA) microspheres and embedded within chitosan guidance channels. NSPCs, seeded in fibrin scaffolds within the channels, differentiated in vitro to betaIII-tubulin positive neurons by immunostaining and mRNA expression, in response to dbcAMP released from PLGA microspheres. After transplantation in spinal cord injured rats, the survival and differentiation of NSPCs was evaluated. Untreated NSPCs, NSPCs transplanted with dbcAMP-releasing microspheres, and NSPCs pre-differentiated with dbcAMP for 4 days in vitro were transplanted after rat spinal cord transection and assessed 2 and 6 weeks later. Interestingly, NSPC survival was highest in the dbcAMP pre-treated group, having approximately 80% survival at both time points, which is remarkable given that stem cell transplantation often results in less than 1% survival at similar times. Importantly, dbcAMP pre-treatment also resulted in the greatest number of in vivo NSPCs differentiated into neurons (37±4%), followed by dbcAMP-microsphere treated NSPCs (27±14%) and untreated NSPCs (15±7%). The reverse trend was observed for NSPC-derived oligodendrocytes and astrocytes, with these populations being highest in untreated NSPCs. This combination strategy of stem cell-loaded chitosan channels implanted in a fully transected spinal cord resulted in extensive axonal regeneration into the injury site, with improved functional recovery after 6 weeks in animals implanted with pre-differentiated stem cells in chitosan channels.
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Bao F, Fleming JC, Golshani R, Pearse DD, Kasabov L, Brown A, Weaver LC. A selective phosphodiesterase-4 inhibitor reduces leukocyte infiltration, oxidative processes, and tissue damage after spinal cord injury. J Neurotrauma 2011; 28:1035-49. [PMID: 21355819 DOI: 10.1089/neu.2010.1575] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
We tested the hypothesis that a selective phosphodiesterase type 4 inhibitor (PDE4-I; IC486051) would attenuate early inflammatory and oxidative processes following spinal cord injury (SCI) when delivered during the first 3 days after injury. Rats receiving a moderately severe thoracic-clip-compression SCI were treated with the PDE4-I (0.5, 1.0, and 3.0 mg/kg IV) in bolus doses from 2-60 h post-injury. Doses at 0.5 mg/kg and 1.0 mg/kg significantly decreased myeloperoxidase (MPO) enzymatic activity (neutrophils), expression of a neutrophil-associated protein and of ED-1 (macrophages), and estimates of lipid peroxidation in cord lesion homogenates at 24 h and 72 h post-injury by 25-40%. The 3.0 mg/kg dose had small or no effects on these measures. The PDE4-I treatment (0.5 or 1.0 mg/kg) reduced expression of the oxidative enzymes gp91(phox), inducible nitric oxide synthase, and cyclooxygenase-2, and diminished free radical generation by up to 40%. Treatment with 0.5 mg/kg PDE4-I improved motor function (as assessed by the Basso-Beattie-Bresnahan scale) significantly from 4-8 weeks after SCI (average difference 1.3 points). Mechanical allodynia elicited from the hindpaw decreased by up to 25%. The PDE4-I treatment also increased white matter volume near the lesion at 8 weeks after SCI. In conclusion, the PDE4-I reduced key markers of oxidative stress and leukocyte infiltration, producing cellular protection, locomotor improvements, and a reduction in neuropathic pain. Early inhibition of PDE4 is neuroprotective after SCI when given acutely and briefly at sufficient doses.
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Affiliation(s)
- Feng Bao
- Spinal Cord Injury Team, Robarts Research Institute, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada.
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47
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Abstract
Oligodendrocytes (OLs) are particularly susceptible to the toxicity of the acute lesion environment after spinal cord injury (SCI). They undergo both necrosis and apoptosis acutely, with apoptosis continuing at chronic time points. Loss of OLs causes demyelination and impairs axon function and survival. In parallel, a rapid and protracted OL progenitor cell proliferative response occurs, especially at the lesion borders. Proliferating and migrating OL progenitor cells differentiate into myelinating OLs, which remyelinate demyelinated axons starting at 2 weeks post-injury. The progression of OL lineage cells into mature OLs in the adult after injury recapitulates development to some degree, owing to the plethora of factors within the injury milieu. Although robust, this endogenous oligogenic response is insufficient against OL loss and demyelination. First, in this review we analyze the major spatial-temporal mechanisms of OL loss, replacement, and myelination, with the purpose of highlighting potential areas of intervention after SCI. We then discuss studies on OL protection and replacement. Growth factors have been used both to boost the endogenous progenitor response, and in conjunction with progenitor transplantation to facilitate survival and OL fate. Considerable progress has been made with embryonic stem cell-derived cells and adult neural progenitor cells. For therapies targeting oligogenesis to be successful, endogenous responses and the effects of the acute and chronic lesion environment on OL lineage cells must be understood in detail, and in relation, the optimal therapeutic window for such strategies must also be determined.
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Affiliation(s)
- Akshata Almad
- Neuroscience Graduate Studies Program, Ohio State University, Columbus, Ohio 43210 USA
- Center for Brain and Spinal Cord Repair, Ohio State University, Columbus, Ohio 43210 USA
| | - F. Rezan Sahinkaya
- Neuroscience Graduate Studies Program, Ohio State University, Columbus, Ohio 43210 USA
- Center for Brain and Spinal Cord Repair, Ohio State University, Columbus, Ohio 43210 USA
| | - Dana M. McTigue
- Center for Brain and Spinal Cord Repair, Ohio State University, Columbus, Ohio 43210 USA
- Department of Neuroscience, Ohio State University, 788 Biomedical Research Tower, 460 W. 12th Ave, Columbus, Ohio 43210 USA
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48
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Nout YS, Culp E, Schmidt MH, Tovar CA, Pröschel C, Mayer-Pröschel M, Noble MD, Beattie MS, Bresnahan JC. Glial restricted precursor cell transplant with cyclic adenosine monophosphate improved some autonomic functions but resulted in a reduced graft size after spinal cord contusion injury in rats. Exp Neurol 2010; 227:159-71. [PMID: 21040723 DOI: 10.1016/j.expneurol.2010.10.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2010] [Revised: 10/13/2010] [Accepted: 10/21/2010] [Indexed: 10/18/2022]
Abstract
Transplantation of glial restricted precursor (GRP) cells has been shown to reduce glial scarring after spinal cord injury (SCI) and, in combination with neuronal restricted precursor (NRP) cells or enhanced expression of neurotrophins, to improve recovery of function after SCI. We hypothesized that combining GRP transplants with rolipram and cAMP would improve functional recovery, similar to that seen after combining Schwann cell transplants with increasing cAMP. A short term study, (1) uninjured control, (2) SCI+vehicle, and (3) SCI+cAMP, showed that spinal cord [cAMP] was increased 14days after SCI. We used 51 male rats subjected to a thoracic SCI for a 12-week survival study: (1) SCI+vehicle, (2) SCI+GRP, (3) SCI+cAMP, (4) SCI+GRP+cAMP, and (5) uninjured endpoint age-matched control (AM). Rolipram was administered for 2weeks after SCI. At 9days after SCI, GRP transplantation and injection of dibutyryl-cAMP into the spinal cord were performed. GRP cells survived, differentiated, and formed extensive transplants that were well integrated with host tissue. Presence of GRP cells increased the amount of tissue in the lesion; however, cAMP reduced the graft size. White matter sparing at the lesion epicenter was not affected. Serotonergic input to the lumbosacral spinal cord was not affected by treatment, but the amount of serotonin immediately caudal to the lesion was reduced in the cAMP groups. Using telemetric monitoring of corpus spongiosum penis pressure we show that the cAMP groups regained the same number of micturitions per 24hours when compared to the AM group, however, the frequency of peak pressures was increased in these groups compared to the AM group. In contrast, the GRP groups had similar frequency of peak pressures compared to baseline and the AM group. Animals that received GRP cells regained the same number of erectile events per 24hours compared to baseline and the AM group. Since cAMP reduced the GRP transplant graft, and some modest positive effects were seen that could be attributable to both GRP or cAMP, future research is required to determine how cAMP affects survival, proliferation, and/or function of progenitor cells and how this is related to function. cAMP may not always be a desirable addition to a progenitor cell transplantation strategy after SCI.
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Affiliation(s)
- Yvette S Nout
- Brain and Spinal Injury Center, Department of Neurological Surgery, 1001 Potrero Ave. Bld 1 Rm 101, University of California, San Francisco, CA 94110, USA.
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49
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Abstract
AbstractResearch to date has indicated that cAMPspecific PDEs, particularly the members of PDE4 family, play a crucial role in the pathogenesis of CNS injury and neurodegeneration by downregulating intracellular levels of cAMP in various cell types. Reduced cAMP signaling results in immune cell activation, inflammation, secondary tissue damage, scar formation and axon growth failure, ultimately leading to an exacerbation of injury, the prevention of endogenous repair and limited functional recovery. Although inhibition of cAMPspecific-PDE activity through the use of drugs like Rolipram has been shown to reverse these deficiencies and mediate neurorepair, an inability to develop selective agents and/or reduce dose-limiting side-effects associated with PDE4 inhibition has hampered their clinical translation. Recent work with more selective pharmacological inhibitors of cAMP-specific PDEs and molecular targeting approaches, along with improved understanding of the basic biology and role of PDEs in pathological processes may enable this promising therapeutic approach to advance clinically and have a similar impact on CNS injury and disease as PDE5 inhibitors have had on the treatment of sexual dysfunction.
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Fouad K, Ghosh M, Vavrek R, Tse AD, Pearse DD. Dose and chemical modification considerations for continuous cyclic AMP analog delivery to the injured CNS. J Neurotrauma 2009; 26:733-40. [PMID: 19397425 DOI: 10.1089/neu.2008.0730] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
In this investigation, two cell-permeable synthetic analogs of cAMP, dibutyryl-cAMP (db-cAMP) and 8-bromo-cAMP, which are widely used to elevate intracellular cAMP levels under experimental conditions, were investigated for their ability to dose-dependently improve histological and functional outcomes following continuous delivery in two models of incomplete spinal cord injury (SCI). The cAMP analogs were delivered via osmotic minipumps at 1-250 mM through an indwelling cortical cannula or by intrathecal infusion for up to 4 weeks after either a T8 unilateral over-hemisection or a C2-3 dorsolateral quadrant lesion, respectively. In both SCI models, continuous db-cAMP delivery was associated with histopathological changes that included sporadic micro-hemorrhage formation and cavitation, enhanced macrophage infiltration and tissue damage at regions beyond the immediate application site; no deleterious or beneficial effect of agent delivery was observed at the spinal injury site. Furthermore, these changes were accompanied by pronounced behavioral deficits that included an absence of progressive locomotor recovery, increased extensor tone, paralysis, and sensory abnormalities. These deleterious effects were not observed in saline-treated animals, in animals in which the db-cAMP dose did not exceed 1 mM, or in those animals that received a high dose (250 mM) of the alternative cAMP analog, 8-bromo-cAMP. These results demonstrate that, for continuous intraparenchymal or intrathecal administration of cAMP analogs for the study of biological or therapeutic effects within the central nervous system (CNS), consideration of the effective concentration applied as well as the potential toxicity of chemical moieties on the parent molecule and/or their activity needs to be taken into account.
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Affiliation(s)
- Karim Fouad
- University of Alberta, Edmonton, Alberta, Canada
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