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Donders Z, Skorupska IJ, Willems E, Mussen F, Broeckhoven JV, Carlier A, Schepers M, Vanmierlo T. Beyond PDE4 inhibition: A comprehensive review on downstream cAMP signaling in the central nervous system. Biomed Pharmacother 2024; 177:117009. [PMID: 38908196 DOI: 10.1016/j.biopha.2024.117009] [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: 03/28/2024] [Revised: 05/27/2024] [Accepted: 06/17/2024] [Indexed: 06/24/2024] Open
Abstract
Cyclic adenosine monophosphate (cAMP) is a key second messenger that regulates signal transduction pathways pivotal for numerous biological functions. Intracellular cAMP levels are spatiotemporally regulated by their hydrolyzing enzymes called phosphodiesterases (PDEs). It has been shown that increased cAMP levels in the central nervous system (CNS) promote neuroplasticity, neurotransmission, neuronal survival, and myelination while suppressing neuroinflammation. Thus, elevating cAMP levels through PDE inhibition provides a therapeutic approach for multiple CNS disorders, including multiple sclerosis, stroke, spinal cord injury, amyotrophic lateral sclerosis, traumatic brain injury, and Alzheimer's disease. In particular, inhibition of the cAMP-specific PDE4 subfamily is widely studied because of its high expression in the CNS. So far, the clinical translation of full PDE4 inhibitors has been hampered because of dose-limiting side effects. Hence, focusing on signaling cascades downstream activated upon PDE4 inhibition presents a promising strategy, offering novel and pharmacologically safe targets for treating CNS disorders. Yet, the underlying downstream signaling pathways activated upon PDE(4) inhibition remain partially elusive. This review provides a comprehensive overview of the existing knowledge regarding downstream mediators of cAMP signaling induced by PDE4 inhibition or cAMP stimulators. Furthermore, we highlight existing gaps and future perspectives that may incentivize additional downstream research concerning PDE(4) inhibition, thereby providing novel therapeutic approaches for CNS disorders.
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Affiliation(s)
- Zoë Donders
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht 6229ER, the Netherlands; Department of Neuroscience, Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, Hasselt 3500, Belgium
| | - Iga Joanna Skorupska
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht 6229ER, the Netherlands; Department of Neuroscience, Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, Hasselt 3500, Belgium; Department of Cell Biology-Inspired Tissue Engineering, MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht 6629ER, the Netherlands
| | - Emily Willems
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht 6229ER, the Netherlands; Department of Neuroscience, Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, Hasselt 3500, Belgium
| | - Femke Mussen
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht 6229ER, the Netherlands; Department of Neuroscience, Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, Hasselt 3500, Belgium; Department of Immunology and Infection, Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, Hasselt 3500, Belgium
| | - Jana Van Broeckhoven
- Department of Immunology and Infection, Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, Hasselt 3500, Belgium; University MS Centre (UMSC) Hasselt - Pelt, Belgium
| | - Aurélie Carlier
- Department of Cell Biology-Inspired Tissue Engineering, MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht 6629ER, the Netherlands
| | - Melissa Schepers
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht 6229ER, the Netherlands; Department of Neuroscience, Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, Hasselt 3500, Belgium; University MS Centre (UMSC) Hasselt - Pelt, Belgium
| | - Tim Vanmierlo
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht 6229ER, the Netherlands; Department of Neuroscience, Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, Hasselt 3500, Belgium; University MS Centre (UMSC) Hasselt - Pelt, Belgium.
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Hemachandran S, Hu N, Kane CJ, Green SH. Cyclic AMP signaling promotes regeneration of cochlear synapses after excitotoxic or noise trauma. Front Cell Neurosci 2024; 18:1363219. [PMID: 38694536 PMCID: PMC11061447 DOI: 10.3389/fncel.2024.1363219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Accepted: 03/27/2024] [Indexed: 05/04/2024] Open
Abstract
Introduction Cochlear afferent synapses connecting inner hair cells to spiral ganglion neurons are susceptible to excitotoxic trauma on exposure to loud sound, resulting in a noise-induced cochlear synaptopathy (NICS). Here we assessed the ability of cyclic AMP-dependent protein kinase (PKA) signaling to promote cochlear synapse regeneration, inferred from its ability to promote axon regeneration in axotomized CNS neurons, another system refractory to regeneration. Methods We mimicked NICS in vitro by applying a glutamate receptor agonist, kainic acid (KA) to organotypic cochlear explant cultures and experimentally manipulated cAMP signaling to determine whether PKA could promote synapse regeneration. We then delivered the cAMP phosphodiesterase inhibitor rolipram via implanted subcutaneous minipumps in noise-exposed CBA/CaJ mice to test the hypothesis that cAMP signaling could promote cochlear synapse regeneration in vivo. Results We showed that the application of the cell membrane-permeable cAMP agonist 8-cpt-cAMP or the cAMP phosphodiesterase inhibitor rolipram promotes significant regeneration of synapses in vitro within twelve hours after their destruction by KA. This is independent of neurotrophin-3, which also promotes synapse regeneration. Moreover, of the two independent signaling effectors activated by cAMP - the cAMP Exchange Protein Activated by cAMP and the cAMP-dependent protein kinase - it is the latter that mediates synapse regeneration. Finally, we showed that systemic delivery of rolipram promotes synapse regeneration in vivo following NICS. Discussion In vitro experiments show that cAMP signaling promotes synapse regeneration after excitotoxic destruction of cochlear synapses and does so via PKA signaling. The cAMP phosphodiesterase inhibitor rolipram promotes synapse regeneration in vivo in noise-exposed mice. Systemic administration of rolipram or similar compounds appears to provide a minimally invasive therapeutic approach to reversing synaptopathy post-noise.
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Affiliation(s)
| | | | | | - Steven H. Green
- Department of Biology, University of Iowa, Iowa City, IA, United States
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3
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Warnecke A, Staecker H, Rohde E, Gimona M, Giesemann A, Szczepek AJ, Di Stadio A, Hochmair I, Lenarz T. Extracellular Vesicles in Inner Ear Therapies-Pathophysiological, Manufacturing, and Clinical Considerations. J Clin Med 2022; 11:jcm11247455. [PMID: 36556073 PMCID: PMC9788356 DOI: 10.3390/jcm11247455] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 12/09/2022] [Accepted: 12/11/2022] [Indexed: 12/23/2022] Open
Abstract
(1) Background: Sensorineural hearing loss is a common and debilitating condition. To date, comprehensive pharmacologic interventions are not available. The complex and diverse molecular pathology that underlies hearing loss may limit our ability to intervene with small molecules. The current review foccusses on the potential for the use of extracellular vesicles in neurotology. (2) Methods: Narrative literature review. (3) Results: Extracellular vesicles provide an opportunity to modulate a wide range of pathologic and physiologic pathways and can be manufactured under GMP conditions allowing for their application in the human inner ear. The role of inflammation in hearing loss with a focus on cochlear implantation is shown. How extracellular vesicles may provide a therapeutic option for complex inflammatory disorders of the inner ear is discussed. Additionally, manufacturing and regulatory issues that need to be addressed to develop EVs as advanced therapy medicinal product for use in the inner ear are outlined. (4) Conclusion: Given the complexities of inner ear injury, novel therapeutics such as extracellular vesicles could provide a means to modulate inflammation, stress pathways and apoptosis in the inner ear.
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Affiliation(s)
- Athanasia Warnecke
- Department of Otolaryngology, Hannover Medical School, 30625 Hannover, Germany
- Cluster of Excellence of the German Research Foundation (DFG; “Deutsche Forschungsgemeinschaft”) “Hearing4all”, 30625 Hannover, Germany
- Correspondence:
| | - Hinrich Staecker
- Department of Otolaryngology Head and Neck Surgery, University of Kansas School of Medicine, Rainbow Blvd., Kansas City, KS 66160, USA
| | - Eva Rohde
- GMP Unit, Spinal Cord Injury & Tissue Regeneration Centre Salzburg (SCI-TReCS), Paracelsus Medical University, 5020 Salzburg, Austria
- Transfer Centre for Extracellular Vesicle Theralytic Technologies (EV-TT), 5020 Salzburg, Austria
- Department of Transfusion Medicine, University Hospital, Salzburger Landeskliniken GesmbH (SALK) Paracelsus Medical University, 5020 Salzburg, Austria
| | - Mario Gimona
- GMP Unit, Spinal Cord Injury & Tissue Regeneration Centre Salzburg (SCI-TReCS), Paracelsus Medical University, 5020 Salzburg, Austria
- Transfer Centre for Extracellular Vesicle Theralytic Technologies (EV-TT), 5020 Salzburg, Austria
- Research Program “Nanovesicular Therapies”, Paracelsus Medical University, 5020 Salzburg, Austria
| | - Anja Giesemann
- Department of Diagnostic and Interventional Neuroradiology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
| | - Agnieszka J. Szczepek
- Department of Otorhinolaryngology, Head and Neck Surgery, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany
- Faculty of Medicine and Health Sciences, University of Zielona Gora, 65-046 Zielona Gora, Poland
| | - Arianna Di Stadio
- Department GF Ingrassia, University of Catania, 95124 Catania, Italy
| | | | - Thomas Lenarz
- Department of Otolaryngology, Hannover Medical School, 30625 Hannover, Germany
- Cluster of Excellence of the German Research Foundation (DFG; “Deutsche Forschungsgemeinschaft”) “Hearing4all”, 30625 Hannover, Germany
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Proteome profile of patients with excellent and poor speech intelligibility after cochlear implantation: Can perilymph proteins predict performance? PLoS One 2022; 17:e0263765. [PMID: 35239655 PMCID: PMC8893673 DOI: 10.1371/journal.pone.0263765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Accepted: 01/26/2022] [Indexed: 11/20/2022] Open
Abstract
Modern proteomic analysis and reliable surgical access to gain liquid inner ear biopsies have enabled in depth molecular characterization of the cochlea microenvironment. In order to clarify whether the protein composition of the perilymph can provide new insights into individual hearing performance after cochlear implantation (CI), computational analysis in correlation to clinical performance after CI were performed based on the proteome profile derived from perilymph samples (liquid biopsies). Perilymph samples from cochlear implant recipients have been analyzed by mass spectrometry (MS). The proteins were identified using the shot-gun proteomics method and quantified and analyzed using Max Quant, Perseus and IPA software. A total of 75 perilymph samples from 68 (adults and children) patients were included in the analysis. Speech perception data one year after implantation were available for 45 patients and these were used for subsequent analysis. According to their hearing performance, patients with excellent (n = 22) and poor (n = 14) performance one year after CI were identified and used for further analysis. The protein composition and statistically significant differences in the two groups were detected by relative quantification of the perilymph proteins. With this procedure, a selection of 287 proteins were identified in at least eight samples in both groups. In the perilymph of the patients with excellent and poor performance, five and six significantly elevated proteins were identified respectively. These proteins seem to be involved in different immunological processes in excellent and poor performer. Further analysis on the role of specific proteins as predictors for poor or excellent performance among CI recipients are mandatory. Combinatory analysis of molecular inner ear profiles and clinical performance data using bioinformatics analysis may open up new possibilities for patient stratification. The impact of such prediction algorithms on diagnosis and treatment needs to be established in further studies.
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Wille I, Harre J, Oehmichen S, Lindemann M, Menzel H, Ehlert N, Lenarz T, Warnecke A, Behrens P. Development of Neuronal Guidance Fibers for Stimulating Electrodes: Basic Construction and Delivery of a Growth Factor. Front Bioeng Biotechnol 2022; 10:776890. [PMID: 35141211 PMCID: PMC8819688 DOI: 10.3389/fbioe.2022.776890] [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: 09/14/2021] [Accepted: 01/05/2022] [Indexed: 12/03/2022] Open
Abstract
State-of-the-art treatment for sensorineural hearing loss is based on electrical stimulation of residual spiral ganglion neurons (SGNs) with cochlear implants (CIs). Due to the anatomical gap between the electrode contacts of the CI and the residual afferent fibers of the SGNs, spatial spreading of the stimulation signal hampers focused neuronal stimulation. Also, the efficiency of a CI is limited because SGNs degenerate over time due to loss of trophic support. A promising option to close the anatomical gap is to install fibers as artificial nerve guidance structures on the surface of the implant and install on these fibers drug delivery systems releasing neuroprotective agents. Here, we describe the first steps in this direction. In the present study, suture yarns made of biodegradable polymers (polyglycolide/poly-ε-caprolactone) serve as the basic fiber material. In addition to the unmodified fiber, also fibers modified with amine groups were employed. Cell culture investigations with NIH 3T3 fibroblasts attested good cytocompatibility to both types of fibers. The fibers were then coated with the extracellular matrix component heparan sulfate (HS) as a biomimetic of the extracellular matrix. HS is known to bind, stabilize, modulate, and sustainably release growth factors. Here, we loaded the HS-carrying fibers with the brain-derived neurotrophic factor (BDNF) which is known to act neuroprotectively. Release of this neurotrophic factor from the fibers was followed over a period of 110 days. Cell culture investigations with spiral ganglion cells, using the supernatants from the release studies, showed that the BDNF delivered from the fibers drastically increased the survival rate of SGNs in vitro. Thus, biodegradable polymer fibers with attached HS and loaded with BDNF are suitable for the protection and support of SGNs. Moreover, they present a promising base material for the further development towards a future neuronal guiding scaffold.
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Affiliation(s)
- Inga Wille
- Institut für Anorganische Chemie, Leibniz Universität Hannover, Hannover, Germany
- Cluster of Excellence Hearing4all, Hannover, Germany
- *Correspondence: Inga Wille, ; Peter Behrens,
| | - Jennifer Harre
- Cluster of Excellence Hearing4all, Hannover, Germany
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hannover, Germany
| | - Sarah Oehmichen
- Institut für Technische Chemie, Technische Universität Braunschweig, Braunschweig, Germany
| | - Maren Lindemann
- Institut für Technische Chemie, Technische Universität Braunschweig, Braunschweig, Germany
| | - Henning Menzel
- Institut für Technische Chemie, Technische Universität Braunschweig, Braunschweig, Germany
| | - Nina Ehlert
- Institut für Anorganische Chemie, Leibniz Universität Hannover, Hannover, Germany
- Cluster of Excellence Hearing4all, Hannover, Germany
| | - Thomas Lenarz
- Cluster of Excellence Hearing4all, Hannover, Germany
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hannover, Germany
| | - Athanasia Warnecke
- Cluster of Excellence Hearing4all, Hannover, Germany
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hannover, Germany
| | - Peter Behrens
- Institut für Anorganische Chemie, Leibniz Universität Hannover, Hannover, Germany
- Cluster of Excellence Hearing4all, Hannover, Germany
- Cluster of Excellence PhoenixD, Hannover, Germany
- *Correspondence: Inga Wille, ; Peter Behrens,
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6
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de Laat B, Kling YE, Schroyen G, Ooms M, Hooker JM, Bormans G, Van Laere K, Ceccarini J. Effects of chronic voluntary alcohol consumption on PDE10A availability: a longitudinal behavioral and [ 18F]JNJ42259152 PET study in rats. Eur J Nucl Med Mol Imaging 2021; 49:492-502. [PMID: 34142214 DOI: 10.1007/s00259-021-05448-3] [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: 03/08/2021] [Accepted: 06/03/2021] [Indexed: 10/21/2022]
Abstract
PURPOSE Phosphodiesterase 10A (PDE10A) is a dual substrate enzyme highly enriched in dopamine-receptive striatal medium spiny neurons, which are involved in psychiatric disorders such as alcohol use disorders (AUD). Although preclinical studies suggest a correlation of PDE10A mRNA expression in neuronal and behavioral responses to alcohol intake, little is known about the effects of alcohol exposure on in vivo PDE10A activity in relation to apparent risk factors for AUD such as decision-making and anxiety. METHODS We performed a longitudinal [18F]JNJ42259152 microPET study to evaluate PDE10A changes over a 9-week intermittent access to alcohol model, including 6 weeks of alcohol exposure, 2 weeks of abstinence followed by 1 week relapse. Parametric PDE10A-binding potential (BPND) images were generated using a Logan reference tissue model with cerebellum as reference region and were analyzed using both a volume-of-interest and voxel-based approach. Moreover, individual decision-making and anxiety levels were assessed with the rat Iowa Gambling Task and open-field test over the IAE model. RESULTS We observed an increased alcohol preference especially in those animals that exhibited poor initial decision-making. The first 2 weeks of alcohol exposure resulted in an increased striatal PDE10A binding (> 10%). Comparing PDE10A-binding potential after 2 versus 4 weeks of exposure showed a significant decreased PDE10A in the caudate-putamen and nucleus accumbens (pFWE-corrected < 0.05). This striatal PDE10A decrease was related to alcohol consumption and preference. Normalization of striatal PDE10A to initial levels was observed after 1 week of relapse, apart from the globus pallidus. CONCLUSION This study shows that chronic voluntary alcohol consumption induces a reversible increased PDE10A enzymatic availability in the striatum, which is related to the amount of alcohol preference. Thus, PDE10A-mediated signaling plays an important role in modulating the reinforcing effects of alcohol, and the data suggest that PDE10A inhibition may have beneficial behavioral effects on alcohol intake.
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Affiliation(s)
- Bart de Laat
- Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | - Yvonne E Kling
- Department of Neurosciences, KU Leuven, Experimental Neurology and Leuven Brain Institute (LBI), Leuven, Belgium.,Center for Brain & Disease Research, Laboratory of Neurobiology, VIB, Leuven, Belgium
| | - Gwen Schroyen
- Department of Imaging and Pathology, Translational MRI, KU Leuven, Leuven, Belgium
| | - Maarten Ooms
- Laboratory for Radiopharmaceutical Research, KU Leuven, Leuven, Belgium
| | - Jacob M Hooker
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Guy Bormans
- Laboratory for Radiopharmaceutical Research, KU Leuven, Leuven, Belgium
| | - Koen Van Laere
- Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium.,Division of Nuclear Medicine, University Hospitals Leuven, Leuven, Belgium
| | - Jenny Ceccarini
- Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium. .,University Hospitals Leuven, Herestraat 49, 3000, Leuven, Belgium.
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7
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Kim YJ, Lee JS, Kim H, Jang JH, Choung YH. Gap Junction-Mediated Intercellular Communication of cAMP Prevents CDDP-Induced Ototoxicity via cAMP/PKA/CREB Pathway. Int J Mol Sci 2021; 22:6327. [PMID: 34199197 PMCID: PMC8231879 DOI: 10.3390/ijms22126327] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 06/07/2021] [Accepted: 06/10/2021] [Indexed: 02/06/2023] Open
Abstract
In the cochlea, non-sensory supporting cells are directly connected to adjacent supporting cells via gap junctions that allow the exchange of small molecules. We have previously shown that the pharmacological regulation of gap junctions alleviates cisplatin (CDDP)-induced ototoxicity in animal models. In this study, we aimed to identify specific small molecules that pass through gap junctions in the process of CDDP-induced auditory cell death and suggest new mechanisms to prevent hearing loss. We found that the cyclic adenosine monophosphate (cAMP) inducer forskolin (FSK) significantly attenuated CDDP-induced auditory cell death in vitro and ex vivo. The activation of cAMP/PKA/CREB signaling was observed in organ of Corti primary cells treated with FSK, especially in supporting cells. Co-treatment with gap junction enhancers such as all-trans retinoic acid (ATRA) and quinoline showed potentiating effects with FSK on cell survival via activation of cAMP/PKA/CREB. In vivo, the combination of FSK and ATRA was more effective for preventing ototoxicity compared to either single treatment. Our study provides the new insight that gap junction-mediated intercellular communication of cAMP may prevent CDDP-induced ototoxicity.
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Affiliation(s)
- Yeon Ju Kim
- Department of Otolaryngology, Ajou University School of Medicine, Suwon 16499, Korea; (Y.J.K.); (H.K.); (J.H.J.)
| | - Jin-Sol Lee
- Department of Medical Sciences, Ajou University Graduate School of Medicine, Suwon 16499, Korea;
| | - Hantai Kim
- Department of Otolaryngology, Ajou University School of Medicine, Suwon 16499, Korea; (Y.J.K.); (H.K.); (J.H.J.)
| | - Jeong Hun Jang
- Department of Otolaryngology, Ajou University School of Medicine, Suwon 16499, Korea; (Y.J.K.); (H.K.); (J.H.J.)
| | - Yun-Hoon Choung
- Department of Otolaryngology, Ajou University School of Medicine, Suwon 16499, Korea; (Y.J.K.); (H.K.); (J.H.J.)
- Department of Medical Sciences, Ajou University Graduate School of Medicine, Suwon 16499, Korea;
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8
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Harre J, Heinkele L, Steffens M, Warnecke A, Lenarz T, Just I, Rohrbeck A. Potentiation of Brain-Derived Neurotrophic Factor-Induced Protection of Spiral Ganglion Neurons by C3 Exoenzyme/Rho Inhibitor. Front Cell Neurosci 2021; 15:602897. [PMID: 33776650 PMCID: PMC7991574 DOI: 10.3389/fncel.2021.602897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 02/19/2021] [Indexed: 11/17/2022] Open
Abstract
Preservation of the excitability of spiral ganglion neurons (SGN) may contribute to an improved speech perception after cochlear implantation. Thus, the application of exogenous neurotrophic factors such as the neurotrophin brain-derived neurotrophic factor (BDNF) to increase SGN survival in vitro and in vivo is a promising pharmacological approach in cochlear implant (CI) research. Due to the difficult pharmacokinetic profile of proteins such as BDNF, there is a quest for small molecules to mediate the survival of SGN or to increase the efficacy of BDNF. The C3 exoenzyme from Clostridium botulinum could be a potential new candidate for the protection and regeneration of SGN. Inhibition of the RhoA GTPase pathway which can be mediated by C3 is described as a promising strategy to enhance axonal regeneration and to exert pro-survival signals in neurons. Nanomolar concentrations of C3, its enzymatically inactive form C3E174Q, and a 26mer C-terminal peptide fragment covering amino acid 156–181 (C3156-181) potentiated the neuroprotective effect on SGN mediated by BDNF in vitro. The neuroprotective effect of C3/BDNF was reduced to the neuroprotective effect of BDNF alone after the treatment with wortmannin, an inhibitor of the phosphatidylinositol-3-kinase (PI3K).The exoenzyme C3 (wild-type and enzyme-deficient) and the C3 peptide fragment C3154–181 present novel biologically active compounds for the protection of the SGN. The exact underlying intracellular mechanisms that mediate the neuroprotective effect are not clarified yet, but the combination of BDNF (TrkB stimulation) and C3 exoenzyme (RhoA inhibition) can be used to protect SGN in vitro.
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Affiliation(s)
- Jennifer Harre
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hannover, Germany.,Cluster of Excellence "Hearing4all" of the German Research Foundation (EXC 2177/1), Hannover, Germany
| | - Laura Heinkele
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hannover, Germany
| | - Melanie Steffens
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hannover, Germany
| | - Athanasia Warnecke
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hannover, Germany.,Cluster of Excellence "Hearing4all" of the German Research Foundation (EXC 2177/1), Hannover, Germany
| | - Thomas Lenarz
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hannover, Germany.,Cluster of Excellence "Hearing4all" of the German Research Foundation (EXC 2177/1), Hannover, Germany
| | - Ingo Just
- Institute of Toxicology, Hannover Medical School, Hannover, Germany
| | - Astrid Rohrbeck
- Institute of Toxicology, Hannover Medical School, Hannover, Germany
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9
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Warnecke A, Harre J, Staecker H, Prenzler N, Strunk D, Couillard‐Despres S, Romanelli P, Hollerweger J, Lassacher T, Auer D, Pachler K, Wietzorrek G, Köhl U, Lenarz T, Schallmoser K, Laner‐Plamberger S, Falk CS, Rohde E, Gimona M. Extracellular vesicles from human multipotent stromal cells protect against hearing loss after noise trauma in vivo. Clin Transl Med 2020; 10:e262. [PMID: 33377658 PMCID: PMC7752163 DOI: 10.1002/ctm2.262] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 12/03/2020] [Accepted: 12/06/2020] [Indexed: 12/21/2022] Open
Abstract
The lack of approved anti-inflammatory and neuroprotective therapies in otology has been acknowledged in the last decades and recent approaches are heralding a new era in the field. Extracellular vesicles (EVs) derived from human multipotent (mesenchymal) stromal cells (MSC) can be enriched in vesicular secretome fractions, which have been shown to exert effects (eg, neuroprotection and immunomodulation) of their parental cells. Hence, MSC-derived EVs may serve as novel drug candidates for several inner ear diseases. Here, we provide first evidence of a strong neuroprotective potential of human stromal cell-derived EVs on inner ear physiology. In vitro, MSC-EV preparations exerted immunomodulatory activity on T cells and microglial cells. Moreover, local application of MSC-EVs to the inner ear significantly attenuated hearing loss and protected auditory hair cells from noise-induced trauma in vivo. Thus, EVs derived from the vesicular secretome of human MSC may represent a next-generation biological drug that can exert protective therapeutic effects in a complex and nonregenerating organ like the inner ear.
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Affiliation(s)
- Athanasia Warnecke
- Department of OtorhinolaryngologyHead and Neck SurgeryHannover Medical SchoolHannoverGermany
| | - Jennifer Harre
- Department of OtorhinolaryngologyHead and Neck SurgeryHannover Medical SchoolHannoverGermany
| | - Hinrich Staecker
- Department of Otolaryngology, Head and Neck SurgeryUniversity of Kansas School of MedicineKansas CityKansas
| | - Nils Prenzler
- Department of OtorhinolaryngologyHead and Neck SurgeryHannover Medical SchoolHannoverGermany
| | - Dirk Strunk
- Institute of Experimental and Clinical Cell TherapySpinal Cord Injury and Tissue Regeneration Centre Salzburg (SCI‐TReCS)Paracelsus Medical UniversitySalzburgAustria
| | - Sebastien Couillard‐Despres
- Institute of Experimental NeuroregenerationSpinal Cord Injury and Tissue Regeneration Centre Salzburg (SCI‐TReCS)Paracelsus Medical UniversitySalzburgAustria
- Austrian Cluster for Tissue RegenerationViennaAustria
| | - Pasquale Romanelli
- Institute of Experimental NeuroregenerationSpinal Cord Injury and Tissue Regeneration Centre Salzburg (SCI‐TReCS)Paracelsus Medical UniversitySalzburgAustria
| | - Julia Hollerweger
- GMP Unit, Spinal Cord Injury and Tissue Regeneration Centre Salzburg (SCI‐TReCS)Paracelsus Medical University (PMU)SalzburgAustria
| | - Teresa Lassacher
- GMP Unit, Spinal Cord Injury and Tissue Regeneration Centre Salzburg (SCI‐TReCS)Paracelsus Medical University (PMU)SalzburgAustria
| | - Daniela Auer
- GMP Unit, Spinal Cord Injury and Tissue Regeneration Centre Salzburg (SCI‐TReCS)Paracelsus Medical University (PMU)SalzburgAustria
| | - Karin Pachler
- Research Program “Nanovesicular Therapies,”Paracelsus Medical University (PMU)SalzburgAustria
| | - Georg Wietzorrek
- Institute of Molecular and Cellular PharmacologyMedical University of InnsbruckInnsbruckAustria
| | - Ulrike Köhl
- Institute of Cellular TherapeuticsHannover Medical School and Clinical ImmunologyUniversity Leipzig, Fraunhofer Institute for Cell Therapy and ImmunologyLeipzigGermany
| | - Thomas Lenarz
- Department of OtorhinolaryngologyHead and Neck SurgeryHannover Medical SchoolHannoverGermany
| | - Katharina Schallmoser
- GMP Unit, Spinal Cord Injury and Tissue Regeneration Centre Salzburg (SCI‐TReCS)Paracelsus Medical University (PMU)SalzburgAustria
- Department of Transfusion MedicineUniversity HospitalSalzburger Landeskliniken GesmbH (SALK) and Paracelsus Medical University (PMU)SalzburgAustria
| | - Sandra Laner‐Plamberger
- Department of Transfusion MedicineUniversity HospitalSalzburger Landeskliniken GesmbH (SALK) and Paracelsus Medical University (PMU)SalzburgAustria
| | - Christine S. Falk
- Institute of Transplant ImmunologyHannover Medical SchoolHannoverGermany
| | - Eva Rohde
- GMP Unit, Spinal Cord Injury and Tissue Regeneration Centre Salzburg (SCI‐TReCS)Paracelsus Medical University (PMU)SalzburgAustria
- Department of Transfusion MedicineUniversity HospitalSalzburger Landeskliniken GesmbH (SALK) and Paracelsus Medical University (PMU)SalzburgAustria
| | - Mario Gimona
- GMP Unit, Spinal Cord Injury and Tissue Regeneration Centre Salzburg (SCI‐TReCS)Paracelsus Medical University (PMU)SalzburgAustria
- Research Program “Nanovesicular Therapies,”Paracelsus Medical University (PMU)SalzburgAustria
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Abstract
The delivery of therapies to the cochlea is notoriously challenging. It is an organ protected by a number of barriers that need to be overcome in the drug delivery process. Additionally, there are multiple sites of possible damage within the cochlea. Despite the many potential sites of damage, acquired otologic insults preferentially damage a single location. While progress has been made in techniques for inner ear drug delivery, the current techniques remain non-specific and our ability to deliver therapies in a cell-specific manner are limited. Fortunately, there are proteins specific to various cell-types within the cochlea (e.g., hair cells, spiral ganglion cells, stria vascularis) that function as biomarkers of site-specific damage. These protein biomarkers have potential to serve as targets for cell-specific inner ear drug delivery. In this manuscript, we review the concept of biomarkers and targeted- inner ear drug delivery and the well-characterized protein biomarkers within each of the locations of interest within the cochlea. Our review will focus on targeted drug delivery in the setting of acquired otologic insults (e.g., ototoxicity, noise-induce hearing loss). The goal is not to discuss therapies to treat acquired otologic insults, rather, to establish potential concepts of how to deliver therapies in a targeted, cell-specific manner. Based on our review, it is clear that future of inner ear drug delivery is a discipline filled with potential that will require collaborative efforts among clinicians and scientists to optimize treatment of otologic insults. Graphical Abstract ![]()
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Somalwar AR, Choudhary AG, Sharma PR, B. N, Sagarkar S, Sakharkar AJ, Subhedar NK, Kokare DM. Cocaine- and amphetamine-regulated transcript peptide (CART) induced reward behavior is mediated via Gi/o dependent phosphorylation of PKA/ERK/CREB pathway. Behav Brain Res 2018; 348:9-21. [DOI: 10.1016/j.bbr.2018.03.035] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 03/08/2018] [Accepted: 03/21/2018] [Indexed: 12/28/2022]
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Schmidt N, Schulze J, Warwas DP, Ehlert N, Lenarz T, Warnecke A, Behrens P. Long-term delivery of brain-derived neurotrophic factor (BDNF) from nanoporous silica nanoparticles improves the survival of spiral ganglion neurons in vitro. PLoS One 2018; 13:e0194778. [PMID: 29584754 PMCID: PMC5870973 DOI: 10.1371/journal.pone.0194778] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 03/11/2018] [Indexed: 11/18/2022] Open
Abstract
Sensorineural hearing loss (SNHL) can be overcome by electrical stimulation of spiral ganglion neurons (SGNs) via a cochlear implant (CI). Restricted CI performance results from the spatial gap between the SGNs and the electrode, but the efficacy of CI is also limited by the degeneration of SGNs as one consequence of SHNL. In the healthy cochlea, the survival of SGNs is assured by endogenous neurotrophic support. Several applications of exogenous neurotrophic supply have been shown to reduce SGN degeneration in vitro and in vivo. In the present study, nanoporous silica nanoparticles (NPSNPs), with an approximate diameter of <100 nm, were loaded with the brain-derived neurotrophic factor (BDNF) to test their efficacy as long-term delivery system for neurotrophins. The neurotrophic factor was released constantly from the NPSNPs over a release period of 80 days when the surface of the nanoparticles had been modified with amino groups. Cell culture investigations with NIH3T3 fibroblasts attest a good general cytocompatibility of the NPSNPs. In vitro experiments with SGNs indicate a significantly higher survival rate of SGNs in cell cultures that contained BDNF-loaded nanoparticles compared to the control culture with unloaded NPSNPs (p<0.001). Importantly, also the amounts of BDNF released up to a time period of 39 days increased the survival rate of SGNs. Thus, NPSNPs carrying BDNF are suitable for the treatment of inner ear disease and for the protection and the support of SGNs. Their nanoscale nature and the fact that a direct contact of the nanoparticles and the SGNs is not necessary for neuroprotective effects, should allow for the facile preparation of nanocomposites, e.g., with biocompatible polymers, to install coatings on implants for the realization of implant-based growth factor delivery systems.
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Affiliation(s)
- Nadeschda Schmidt
- Institut für Anorganische Chemie, Leibniz Universität Hannover, Hannover, Germany
- Cluster of Excellence Hearing4all, Hannover, Germany
| | - Jennifer Schulze
- Cluster of Excellence Hearing4all, Hannover, Germany
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hannover, Germany
| | - Dawid P. Warwas
- Institut für Anorganische Chemie, Leibniz Universität Hannover, Hannover, Germany
| | - Nina Ehlert
- Institut für Anorganische Chemie, Leibniz Universität Hannover, Hannover, Germany
- Cluster of Excellence Hearing4all, Hannover, Germany
| | - Thomas Lenarz
- Cluster of Excellence Hearing4all, Hannover, Germany
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hannover, Germany
| | - Athanasia Warnecke
- Cluster of Excellence Hearing4all, Hannover, Germany
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hannover, Germany
| | - Peter Behrens
- Institut für Anorganische Chemie, Leibniz Universität Hannover, Hannover, Germany
- Cluster of Excellence Hearing4all, Hannover, Germany
- * E-mail:
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Mittal R, Bencie N, Shaikh N, Mittal J, Liu XZ, Eshraghi AA. Role of Cyclic Nucleotide Phosphodiesterases in Inner Ear and Hearing. Front Physiol 2017; 8:908. [PMID: 29163231 PMCID: PMC5677782 DOI: 10.3389/fphys.2017.00908] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 10/26/2017] [Indexed: 12/22/2022] Open
Affiliation(s)
- Rahul Mittal
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Nicole Bencie
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Noah Shaikh
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Jeenu Mittal
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Xue Zhong Liu
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Adrien A Eshraghi
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, United States
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Rolipram potentiates bevacizumab-induced cell death in human glioblastoma stem-like cells. Life Sci 2017; 173:11-19. [PMID: 28202289 DOI: 10.1016/j.lfs.2017.02.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 02/06/2017] [Accepted: 02/11/2017] [Indexed: 12/20/2022]
Abstract
AIMS Glioblastoma cancer stem-like cells (GCSCs) promote themselves proliferation by secreting the vascular endothelial growth factor A (VEGFA) in an autocrine manner, positively regulated by phosphodiesterase IV (PDE4). In the current study, we investigated the putative cytotoxic effect of bevacizumab, a VEGFA blocker, alone and in combination with a specific inhibitor of PDE4 called rolipram on GCSCs isolated from human surgical tumor specimen with a focus on PI3K/AKT pathway. MAIN METHODS CD133+/CD15+ GCSCs were characterized by flow cytometry and expanded in a serum-free primary culture system. The cell survival, apoptosis, and protein expression values were measured using MTT assay, TUNEL staining and western blot, successively. Intracellular cAMP and free secreted VEGFA levels were assessed by cAMP enzyme immunoassay and ELISA, respectively. KEY FINDINGS Bevacizumab suppressed GCSCs survival with IC50~6.5μg/ml and enhanced the levels of apoptosis, p53 and cleaved-caspase3 along with a decrease in free VEGFA levels and ERKs activation. However, there was no significant modulation of AKT phosphorylation on serine 473, the intracellular PDE4A, VEGFA and cAMP levels. More cytotoxicity in co-treated cells coupled with a more substantial decline in the free VEGFA levels and a greater increase in the quantities of p53 and cleaved-caspase3 compared to those treated with bevacizumab alone. Co-treatment reduced phospho-AKT, endogenous VEGFA and PDE4A values but elevated cAMP levels. SIGNIFICANCE This study highlighted a booster cytotoxic effect of combined rolipram and bevacizumab treatment on the GCSCs primary culture, suggesting that this approach is warranted in treatment of GBMs overexpressing VEGFA and PDE4A.
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Peng S, Shi Z, Su H, So KF, Cui Q. Increased production of omega-3 fatty acids protects retinal ganglion cells after optic nerve injury in mice. Exp Eye Res 2016; 148:90-96. [PMID: 27264241 DOI: 10.1016/j.exer.2016.06.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Revised: 05/19/2016] [Accepted: 06/01/2016] [Indexed: 02/08/2023]
Abstract
Injury to the central nervous system causes progressive degeneration of injured axons, leading to loss of the neuronal bodies. Neuronal survival after injury is a prerequisite for successful regeneration of injured axons. In this study, we investigated the effects of increased production of omega-3 fatty acids and elevation of cAMP on retinal ganglion cell (RGC) survival and axonal regeneration after optic nerve (ON) crush injury in adult mice. We found that increased production of omega-3 fatty acids in mice enhanced RGC survival, but not axonal regeneration, over a period of 3 weeks after ON injury. cAMP elevation promoted RGC survival in wild type mice, but no significant difference in cell survival was seen in mice over-producing omega-3 fatty acids and receiving intravitreal injections of CPT-cAMP, suggesting that cAMP elevation protects RGCs after injury but does not potentiate the actions of the omega-3 fatty acids. The observed omega-3 fatty acid-mediated neuroprotection is likely achieved partially through ERK1/2 signaling as inhibition of this pathway by PD98059 hindered, but did not completely block, RGC protection. Our study thus enhances our current understanding of neural repair after CNS injury, including the visual system.
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Affiliation(s)
- Shanshan Peng
- GHM Institute of CNS Regeneration, Jinan University, Guangzhou, China; Guangdong Key Laboratory of Brain, Function and Diseases, Jinan University, Guangzhou, China; Joint International Research Laboratory of CNS Regeneration, Ministry of Education of PRC, Jinan University, Guangzhou, China
| | - Zhe Shi
- GHM Institute of CNS Regeneration, Jinan University, Guangzhou, China
| | - Huanxing Su
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China
| | - Kwok-Fai So
- GHM Institute of CNS Regeneration, Jinan University, Guangzhou, China; Guangdong Key Laboratory of Brain, Function and Diseases, Jinan University, Guangzhou, China; Joint International Research Laboratory of CNS Regeneration, Ministry of Education of PRC, Jinan University, Guangzhou, China
| | - Qi Cui
- GHM Institute of CNS Regeneration, Jinan University, Guangzhou, China; Guangdong Key Laboratory of Brain, Function and Diseases, Jinan University, Guangzhou, China; Joint International Research Laboratory of CNS Regeneration, Ministry of Education of PRC, Jinan University, Guangzhou, China.
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The Three-Dimensional Culture System with Matrigel and Neurotrophic Factors Preserves the Structure and Function of Spiral Ganglion Neuron In Vitro. Neural Plast 2016; 2016:4280407. [PMID: 27057364 PMCID: PMC4736769 DOI: 10.1155/2016/4280407] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Accepted: 11/10/2015] [Indexed: 02/06/2023] Open
Abstract
Whole organ culture of the spiral ganglion region is a resourceful model system facilitating manipulation and analysis of live sprial ganglion neurons (SGNs). Three-dimensional (3D) cultures have been demonstrated to have many biomedical applications, but the effect of 3D culture in maintaining the SGNs structure and function in explant culture remains uninvestigated. In this study, we used the matrigel to encapsulate the spiral ganglion region isolated from neonatal mice. First, we optimized the matrigel concentration for the 3D culture system and found the 3D culture system protected the SGNs against apoptosis, preserved the structure of spiral ganglion region, and promoted the sprouting and outgrowth of SGNs neurites. Next, we found the 3D culture system promoted growth cone growth as evidenced by a higher average number and a longer average length of filopodia and a larger growth cone area. 3D culture system also significantly elevated the synapse density of SGNs. Last, we found that the 3D culture system combined with neurotrophic factors had accumulated effects in promoting the neurites outgrowth compared with 3D culture or NFs treatment only groups. Together, we conclude that the 3D culture system preserves the structure and function of SGN in explant culture.
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Rodríguez-Seoane C, Ramos A, Korth C, Requena JR. DISC1 regulates expression of the neurotrophin VGF through the PI3K/AKT/CREB pathway. J Neurochem 2015. [DOI: 10.1111/jnc.13258] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Carmen Rodríguez-Seoane
- CIMUS Biomedical Research Institute & Department of Medicine; University of Santiago de Compostela-IDIS; Santiago de Compostela Spain
| | - Adriana Ramos
- CIMUS Biomedical Research Institute & Department of Medicine; University of Santiago de Compostela-IDIS; Santiago de Compostela Spain
- Department of Psychiatry and Behavioral Sciences; The Johns Hopkins University School of Medicine; Baltimore Maryland USA
| | - Carsten Korth
- Department of Neuropathology; Heinrich Heine University; Medical School; Düsseldorf Germany
| | - Jesús R. Requena
- CIMUS Biomedical Research Institute & Department of Medicine; University of Santiago de Compostela-IDIS; Santiago de Compostela Spain
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Neuronal Survival, Morphology and Outgrowth of Spiral Ganglion Neurons Using a Defined Growth Factor Combination. PLoS One 2015; 10:e0133680. [PMID: 26263175 PMCID: PMC4532470 DOI: 10.1371/journal.pone.0133680] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 06/29/2015] [Indexed: 12/25/2022] Open
Abstract
Objectives The functionality of cochlear implants (CI) depends, among others, on the number and excitability of surviving spiral ganglion neurons (SGN). The spatial separation between the SGN, located in the bony axis of the inner ear, and the CI, which is inserted in the scala tympani, results in suboptimal performance of CI patients and may be decreased by attracting the SGN neurites towards the electrode contacts. Neurotrophic factors (NTFs) can support neuronal survival and neurite outgrowth. Methods Since brain-derived neurotrophic factor (BDNF) is well known for its neuroprotective effect and ciliary neurotrophic factor (CNTF) increases neurite outgrowth, we evaluated if the combination of BDNF and CNTF leads to an enhanced neuronal survival with extended neurite outgrowth. Both NTFs were added in effective high concentrations (BDNF 50ng/ml, CNTF 100ng/ml), alone and in combination, to cultured dissociated SGN of neonatal rats for 48 hours. Results The neuronal survival and neurite outgrowth were significantly higher in SGN treated with the combination of the two NTFs compared to treatment with each factor alone. Additionally, with respect to the morphology, the combination of BDNF and CNTF leads to a significantly higher number of bipolar neurons and a decreased number of neurons without neurites in culture. Conclusion The combination of BDNF and CNTF shows a great potential to increase the neuronal survival and the number of bipolar neurons in vitro and to regenerate retracted nerve fibers.
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Glueckert R, Pritz CO, Roy S, Dudas J, Schrott-Fischer A. Nanoparticle mediated drug delivery of rolipram to tyrosine kinase B positive cells in the inner ear with targeting peptides and agonistic antibodies. Front Aging Neurosci 2015; 7:71. [PMID: 26042029 PMCID: PMC4436893 DOI: 10.3389/fnagi.2015.00071] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 04/20/2015] [Indexed: 12/22/2022] Open
Abstract
Aim: Systemic pharmacotherapies have limitation due to blood-labyrinth barrier, so local delivery via the round window membrane opens a path for effective treatment. Multifunctional nanoparticle (NP)-mediated cell specific drug delivery may enhance efficacy and reduce side effects. Different NPs with ligands to target TrkB receptor were tested. Distribution, uptake mechanisms, trafficking, and bioefficacy of drug release of rolipram loaded NPs were evaluated. Methods: We tested lipid based nanocapsules (LNCs), Quantum Dot, silica NPs with surface modification by peptides mimicking TrkB or TrkB activating antibodies. Bioefficacy of drug release was tested with rolipram loaded LNCs to prevent cisplatin-induced apoptosis. We established different cell culture models with SH-SY-5Y and inner ear derived cell lines and used neonatal and adult mouse explants. Uptake and trafficking was evaluated with FACS and confocal as well as transmission electron microscopy. Results: Plain NPs show some selectivity in uptake related to the in vitro system properties, carrier material, and NP size. Some peptide ligands provide enhanced targeted uptake to neuronal cells but failed to show this in cell cultures. Agonistic antibodies linked to silica NPs showed TrkB activation and enhanced binding to inner ear derived cells. Rolipram loaded LNCs proved as effective carriers to prevent cisplatin-induced apoptosis. Discussion: Most NPs with targeting ligands showed limited effects to enhance uptake. NP aggregation and unspecific binding may change uptake mechanisms and impair endocytosis by an overload of NPs. This may affect survival signaling. NPs with antibodies activate survival signaling and show effective binding to TrkB positive cells but needs further optimization for specific internalization. Bioefficiacy of rolipram release confirms LNCs as encouraging vectors for drug delivery of lipophilic agents to the inner ear with ideal release characteristics independent of endocytosis.
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Affiliation(s)
- Rudolf Glueckert
- Department of Otolaryngology, Medical University of Innsbruck Innsbruck, Austria ; University Clinics of Innsbruck, Tiroler Landeskrankenanstalten GmbH-TILAK Innsbruck, Austria
| | - Christian O Pritz
- Department of Otolaryngology, Medical University of Innsbruck Innsbruck, Austria ; Department of Genetics, Institute of Life Sciences, Hebrew University of Jerusalem Jerusalem, Israel
| | - Soumen Roy
- Department of Otolaryngology, Medical University of Innsbruck Innsbruck, Austria
| | - Jozsef Dudas
- Department of Otolaryngology, Medical University of Innsbruck Innsbruck, Austria
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Liu Z, Liu Y, Gao R, Li H, Dunn T, Wu P, Smith RG, Sarkar PS, Fang X. Ethanol suppresses PGC-1α expression by interfering with the cAMP-CREB pathway in neuronal cells. PLoS One 2014; 9:e104247. [PMID: 25099937 PMCID: PMC4123904 DOI: 10.1371/journal.pone.0104247] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 06/25/2014] [Indexed: 11/26/2022] Open
Abstract
Alcohol intoxication results in neuronal apoptosis, neurodegeneration and manifest with impaired balance, loss of muscle coordination and behavioral changes. One of the early events of alcohol intoxication is mitochondrial (Mt) dysfunction and disruption of intracellular redox homeostasis. The mechanisms by which alcohol causes Mt dysfunction, disrupts cellular redox homeostasis and triggers neurodegeneration remains to be further investigated. Proliferator-activated receptor gamma co-activator 1-alpha (PGC-1α) plays critical roles in regulating Mt biogenesis and respiration, cellular antioxidant defense mechanism, and maintenance of neuronal integrity and function. In this study, we sought to investigate whether alcohol causes Mt dysfunction and triggers neurodegeneration by suppressing PGC-1α expression. We report that ethanol suppresses PGC-1α expression, and impairs mitochondrial function and enhances cellular toxicity in cultured neuronal cell line and also in human fetal brain neural stem cell-derived primary neurons. Moreover, we report that cells over-expressing exogenous PGC-1α or treated with Rolipram, a selective phosphodiesterase-4 inhibitor, ameliorate alcohol-induced cellular toxicity. Further analysis show that ethanol decreases steady-state intracellular cAMP levels, and thus depletes phosphorylation of cAMP-response element binding protein (p-CREB), the key transcription factor that regulates transcription of PGC-1α gene. Accordingly, we found PGC-1α promoter activity and transcription was dramatically repressed in neuronal cells when exposed to ethanol, suggesting that ethanol blunts cAMP→CREB signaling pathway to interfere with the transcription of PGC-1α. Ethanol-mediated decrease in PGC-1α activity results in the disruption of Mt respiration and function and higher cellular toxicity. This study might lead to potential therapeutic intervention to ameliorate alcohol-induced apoptosis and/or neurodegeneration by targeting PGC-1α.
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Affiliation(s)
- Zilong Liu
- Department of Neurology, University of Texas Medical Branch, Galveston, Texas, United States of America
- Department of Forensic Medicine, Tongji Medical College of Huazhong University of Science and Technology, Wuhan, China
| | - Yongping Liu
- Department of Neurology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Rui Gao
- Department of Neurology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Haixia Li
- Department of Internal Medicine/Gastroenterology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Tiffany Dunn
- Department of Neuroscience & Cell Biology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Ping Wu
- Department of Neuroscience & Cell Biology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Robert G. Smith
- Department of Neurology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Partha S. Sarkar
- Department of Neurology, University of Texas Medical Branch, Galveston, Texas, United States of America
- Department of Neuroscience & Cell Biology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Xiang Fang
- Department of Neurology, University of Texas Medical Branch, Galveston, Texas, United States of America
- * E-mail:
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