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Ranglani S, Ashton A, Mahfooz K, Komorowska J, Graur A, Kabbani N, Garcia-Rates S, Greenfield S. A Novel Bioactive Peptide, T14, Selectively Activates mTORC1 Signalling: Therapeutic Implications for Neurodegeneration and Other Rapamycin-Sensitive Applications. Int J Mol Sci 2023; 24:9961. [PMID: 37373106 DOI: 10.3390/ijms24129961] [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: 05/12/2023] [Revised: 06/06/2023] [Accepted: 06/07/2023] [Indexed: 06/29/2023] Open
Abstract
T14 modulates calcium influx via the α-7 nicotinic acetylcholine receptor to regulate cell growth. Inappropriate triggering of this process has been implicated in Alzheimer's disease (AD) and cancer, whereas T14 blockade has proven therapeutic potential in in vitro, ex vivo and in vivo models of these pathologies. Mammalian target of rapamycin complex 1 (mTORC1) is critical for growth, however its hyperactivation is implicated in AD and cancer. T14 is a product of the longer 30mer-T30. Recent work shows that T30 drives neurite growth in the human SH-SY5Y cell line via the mTOR pathway. Here, we demonstrate that T30 induces an increase in mTORC1 in PC12 cells, and ex vivo rat brain slices containing substantia nigra, but not mTORC2. The increase in mTORC1 by T30 in PC12 cells is attenuated by its blocker, NBP14. Moreover, in post-mortem human midbrain, T14 levels correlate significantly with mTORC1. Silencing mTORC1 reverses the effects of T30 on PC12 cells measured via AChE release in undifferentiated PC12 cells, whilst silencing mTORC2 does not. This suggests that T14 acts selectively via mTORC1. T14 blockade offers a preferable alternative to currently available blockers of mTOR as it would enable selective blockade of mTORC1, thereby reducing side effects associated with generalised mTOR blockade.
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Affiliation(s)
- Sanskar Ranglani
- Neuro Bio Ltd., Building F5, Culham Science Centre, Abingdon OX14 3DB, UK
| | - Anna Ashton
- Neuro Bio Ltd., Building F5, Culham Science Centre, Abingdon OX14 3DB, UK
| | - Kashif Mahfooz
- Neuro Bio Ltd., Building F5, Culham Science Centre, Abingdon OX14 3DB, UK
| | - Joanna Komorowska
- Neuro Bio Ltd., Building F5, Culham Science Centre, Abingdon OX14 3DB, UK
| | - Alexandru Graur
- School of Systems Biology, George Mason University, Fairfax, VA 22030, USA
| | - Nadine Kabbani
- School of Systems Biology, George Mason University, Fairfax, VA 22030, USA
| | - Sara Garcia-Rates
- Neuro Bio Ltd., Building F5, Culham Science Centre, Abingdon OX14 3DB, UK
| | - Susan Greenfield
- Neuro Bio Ltd., Building F5, Culham Science Centre, Abingdon OX14 3DB, UK
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2
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Asker H, Yilmaz-Oral D, Oztekin CV, Gur S. An update on the current status and future prospects of erectile dysfunction following radical prostatectomy. Prostate 2022; 82:1135-1161. [PMID: 35579053 DOI: 10.1002/pros.24366] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Revised: 03/30/2022] [Accepted: 04/20/2022] [Indexed: 12/15/2022]
Abstract
BACKGROUND Radical prostatectomy (RP) and radiation treatment are standard options for localized prostate cancer. Even though nerve-sparing techniques have been increasingly utilized in RP, erectile dysfunction (ED) due to neuropraxia remains a frequent complication. Erectile function recovery rates after RP remain unsatisfactory, and many men still suffer despite the availability of various therapies. OBJECTIVE This systematic review aims to summarize the current treatments for post-RP-ED, assess the underlying pathological mechanisms, and emphasize promising therapeutic strategies based on the evidence from basic research. METHOD Evaluation and review of articles on the relevant topic published between 2010 and 2021, which are indexed and listed in the PubMed database. RESULTS Phosphodiesterase type 5 inhibitors, intracavernosal and intraurethral injections, vacuum erection devices, pelvic muscle training, and surgical procedures are utilized for penile rehabilitation. Clinical trials evaluating the efficacy of erectogenic drugs in this setting are conflicting and far from being conclusive. The use of androgen deprivation therapy in certain scenarios after RP further exacerbates the already problematic situation and emphasizes the need for effective treatment strategies. CONCLUSION This article is a detailed overview focusing on the pathophysiology and mechanism of the nerve injury developed during RP and a compilation of various strategies to induce cavernous nerve regeneration to improve erectile function (EF). These strategies include stem cell therapy, gene therapy, growth factors, low-intensity extracorporeal shockwave therapy, immunophilins, and various pharmacological approaches that have induced improvements in EF in experimental models of cavernous nerve injury. Many of the mentioned strategies can improve EF following RP if transformed into clinically applicable safe, and effective techniques with reproducible outcomes.
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Affiliation(s)
- Heba Asker
- Department of Pharmacology, Faculty of Pharmacy, Ankara University, Ankara, Turkey
- Department of Medical Pharmacology, Faculty of Medicine, Lokman Hekim University, Ankara, Turkey
- Graduate School of Health Sciences, Ankara University, Ankara, Turkey
| | - Didem Yilmaz-Oral
- Department of Pharmacology, Faculty of Pharmacy, Cukurova University, Adana, Turkey
| | - Cetin Volkan Oztekin
- Department of Urology, Faculty of Medicine, University of Kyrenia, Girne, Turkey
| | - Serap Gur
- Department of Pharmacology, Faculty of Pharmacy, Ankara University, Ankara, Turkey
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3
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Feng H, Hu L, Zhu H, Tao L, Wu L, Zhao Q, Gao Y, Gong Q, Mao F, Li X, Zhou H, Li J, Zhang H. Repurposing antimycotic ciclopirox olamine as a promising anti-ischemic stroke agent. Acta Pharm Sin B 2020; 10:434-446. [PMID: 32140390 PMCID: PMC7049605 DOI: 10.1016/j.apsb.2019.08.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 07/18/2019] [Accepted: 07/19/2019] [Indexed: 02/06/2023] Open
Abstract
Ischemic stroke is a severe disorder resulting from acute cerebral thrombosis. Here we demonstrated that post-ischemic treatment with ciclopirox olamine (CPX), a potent antifungal clinical drug, alleviated brain infarction, neurological deficits and brain edema in a classic rat model of ischemic stroke. Single dose post-ischemic administration of CPX provided a long-lasting neuroprotective effect, which can be further enhanced by multiple doses administration of CPX. CPX also effectively reversed ischemia-induced neuronal loss, glial activation as well as blood–brain barrier (BBB) damage. Employing quantitative phosphoproteomic analysis, 130 phosphosites in 122 proteins were identified to be significantly regulated by CPX treatment in oxygen glucose deprivation (OGD)-exposed SH-SY5Y cells, which revealed that phosphokinases and cell cycle-related phosphoproteins were largely influenced. Subsequently, we demonstrated that CPX markedly enhanced the AKT (protein kinase B, PKB/AKT) and GSK3β (glycogen synthase kinase 3β) phosphorylation in OGD-exposed SH-SY5Y cells, and regulated the cell cycle progression and nitric oxide (NO) release in lipopolysaccharide (LPS)-induced BV-2 cells, which may contribute to its ameliorative effects against ischemia-associated neuronal death and microglial inflammation. Our study suggests that CPX could be a promising compound to reduce multiple ischemic injuries; however, further studies will be needed to clarify the molecular mechanisms involved.
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Maffioli E, Schulte C, Nonnis S, Grassi Scalvini F, Piazzoni C, Lenardi C, Negri A, Milani P, Tedeschi G. Proteomic Dissection of Nanotopography-Sensitive Mechanotransductive Signaling Hubs that Foster Neuronal Differentiation in PC12 Cells. Front Cell Neurosci 2018; 11:417. [PMID: 29354032 PMCID: PMC5758595 DOI: 10.3389/fncel.2017.00417] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 12/12/2017] [Indexed: 12/11/2022] Open
Abstract
Neuronal cells are competent in precisely sensing nanotopographical features of their microenvironment. The perceived microenvironmental information will be “interpreted” by mechanotransductive processes and impacts on neuronal functioning and differentiation. Attempts to influence neuronal differentiation by engineering substrates that mimic appropriate extracellular matrix (ECM) topographies are hampered by the fact that profound details of mechanosensing/-transduction complexity remain elusive. Introducing omics methods into these biomaterial approaches has the potential to provide a deeper insight into the molecular processes and signaling cascades underlying mechanosensing/-transduction but their exigence in cellular material is often opposed by technical limitations of major substrate top-down fabrication methods. Supersonic cluster beam deposition (SCBD) allows instead the bottom-up fabrication of nanostructured substrates over large areas characterized by a quantitatively controllable ECM-like nanoroughness that has been recently shown to foster neuron differentiation and maturation. Exploiting this capacity of SCBD, we challenged mechanosensing/-transduction and differentiative behavior of neuron-like PC12 cells with diverse nanotopographies and/or changes of their biomechanical status, and analyzed their phosphoproteomic profiles in these settings. Versatile proteins that can be associated to significant processes along the mechanotransductive signal sequence, i.e., cell/cell interaction, glycocalyx and ECM, membrane/f-actin linkage and integrin activation, cell/substrate interaction, integrin adhesion complex, actomyosin organization/cellular mechanics, nuclear organization, and transcriptional regulation, were affected. The phosphoproteomic data suggested furthermore an involvement of ILK, mTOR, Wnt, and calcium signaling in these nanotopography- and/or cell mechanics-related processes. Altogether, potential nanotopography-sensitive mechanotransductive signaling hubs participating in neuronal differentiation were dissected.
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Affiliation(s)
- Elisa Maffioli
- Department of Veterinary Medicine, Università degli Studi di Milano, Milan, Italy
| | - Carsten Schulte
- Centre for Nanostructured Materials and Interfaces, Università degli Studi di Milano, Milan, Italy.,Fondazione Filarete, Milan, Italy
| | - Simona Nonnis
- Department of Veterinary Medicine, Università degli Studi di Milano, Milan, Italy.,Fondazione Filarete, Milan, Italy
| | - Francesca Grassi Scalvini
- Department of Veterinary Medicine, Università degli Studi di Milano, Milan, Italy.,Fondazione Filarete, Milan, Italy
| | - Claudio Piazzoni
- Centre for Nanostructured Materials and Interfaces, Università degli Studi di Milano, Milan, Italy
| | - Cristina Lenardi
- Centre for Nanostructured Materials and Interfaces, Università degli Studi di Milano, Milan, Italy
| | - Armando Negri
- Department of Veterinary Medicine, Università degli Studi di Milano, Milan, Italy.,Fondazione Filarete, Milan, Italy
| | - Paolo Milani
- Centre for Nanostructured Materials and Interfaces, Università degli Studi di Milano, Milan, Italy
| | - Gabriella Tedeschi
- Department of Veterinary Medicine, Università degli Studi di Milano, Milan, Italy.,Fondazione Filarete, Milan, Italy
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Thomson SE, Charalambous C, Smith CA, Tsimbouri PM, Déjardin T, Kingham PJ, Hart AM, Riehle MO. Microtopographical cues promote peripheral nerve regeneration via transient mTORC2 activation. Acta Biomater 2017; 60:220-231. [PMID: 28754648 PMCID: PMC5593812 DOI: 10.1016/j.actbio.2017.07.031] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 07/04/2017] [Accepted: 07/20/2017] [Indexed: 12/16/2022]
Abstract
Despite microsurgical repair, recovery of function following peripheral nerve injury is slow and often incomplete. Outcomes could be improved by an increased understanding of the molecular biology of regeneration and by translation of experimental bioengineering strategies. Topographical cues have been shown to be powerful regulators of the rate and directionality of neurite regeneration, and in this study we investigated the downstream molecular effects of linear micropatterned structures in an organotypic explant model. Linear topographical cues enhanced neurite outgrowth and our results demonstrated that the mTOR pathway is important in regulating these responses. mTOR gene expression peaked between 48 and 72 h, coincident with the onset of rapid neurite outgrowth and glial migration, and correlated with neurite length at 48 h. mTOR protein was located to glia and in a punctate distribution along neurites. mTOR levels peaked at 72 h and were significantly increased by patterned topography (p < 0.05). Furthermore, the topographical cues could override pharmacological inhibition. Downstream phosphorylation assays and inhibition of mTORC1 using rapamycin highlighted mTORC2 as an important mediator, and more specific therapeutic target. Quantitative immunohistochemistry confirmed the presence of the mTORC2 component rictor at the regenerating front where it co-localised with F-actin and vinculin. Collectively, these results provide a deeper understanding of the mechanism of action of topography on neural regeneration, and support the incorporation of topographical patterning in combination with pharmacological mTORC2 potentiation within biomaterial constructs used to repair peripheral nerves. Statement of Significance Peripheral nerve injury is common and functionally devastating. Despite microsurgical repair, healing is slow and incomplete, with lasting functional deficit. There is a clear need to translate bioengineering approaches and increase our knowledge of the molecular processes controlling nerve regeneration to improve the rate and success of healing. Topographical cues are powerful determinants of neurite outgrowth and represent a highly translatable engineering strategy. Here we demonstrate, for the first time, that microtopography potentiates neurite outgrowth via the mTOR pathway, with the mTORC2 subtype being of particular importance. These results give further evidence for the incorporation of microtopographical cues into peripheral nerve regeneration conduits and indicate that mTORC2 may be a suitable therapeutic target to potentiate nerve regeneration.
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Alemdar AY, Sadi D, McAlister VC, Mendez I. Liposomal Formulations of Tacrolimus and Rapamycin Increase Graft Survival and Fiber Outgrowth of Dopaminergic Grafts. Cell Transplant 2017; 13:263-71. [PMID: 15191164 DOI: 10.3727/000000004783983936] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The immunosuppressive drugs tacrolimus (TAC) and rapamycin (RAPA) have both been found to have neuroprotective effects on dopaminergic neurons. The purpose of the present study was to investigate whether liposomal formulations of these drugs administered directly into the brain improve cell survival and fiber outgrowth. Rats with unilateral 6-hydroxydopamine lesions were transplanted with 800,000 fetal rat ventral mesencephalic cells and randomly divided to one of four groups. Group 1 received a transplant containing cells only; group 2 received a cell suspension containing 0.68 μM liposomal RAPA (LRAPA); group 3 received a cell suspension containing 2.0 μM liposomal TAC (LTAC); and group 4 received a cell suspension containing a liposomal formulation of both 0.68 μM RAPA and 2.0 μM TAC (LRAPATAC). Rats were sacrificed after 6 weeks, and cell survival and fiber outgrowth were assessed using tyrosine hydroxylase (TH) immunohistochemistry. The animals receiving a cell suspension containing either LTAC or LRAPATAC were found to have significantly more surviving TH-immunoreactive (TH-ir) cells than the control group receiving cells only. The group receiving LTAC had significantly longer fibers, the group receiving LRAPA had significantly more fibers close to the graft, and the group receiving LRAPATAC had significantly more fibers at all distances. This study shows the feasibility of using liposomal formulations of neuroimmunophilins directly in the brain at the time of implantation to improve graft survival and fiber outgrowth. Furthermore, we have shown that the combination of LTAC and LRAPA has a synergistic effect. These compounds may play an important role in optimizing graft survival and host reinnervation in cellmediated brain repair strategies for the treatment of neurological conditions.
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Affiliation(s)
- Aylin Y Alemdar
- Department of Anatomy and Neurobiology, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4H7
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Kaya-Tilki E, Dikmen M, Ozturk Y. Effects of DNMT and HDAC Inhibitors (RG108 and Trichostatin A) on NGF-induced Neurite Outgrowth and Cellular Migration. INT J PHARMACOL 2016. [DOI: 10.3923/ijp.2016.351.360] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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8
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Mustafa AM, Caprioli G, Dikmen M, Kaya E, Maggi F, Sagratini G, Vittori S, Öztürk Y. Evaluation of neuritogenic activity of cultivated, wild and commercial roots of Gentiana lutea L. J Funct Foods 2015. [DOI: 10.1016/j.jff.2015.09.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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9
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Mustafa AM, Maggi F, Papa F, Kaya E, Dikmen M, Öztürk Y. Isofuranodiene: A neuritogenic compound isolated from wild celery (Smyrnium olusatrum L., Apiaceae). Food Chem 2015; 192:782-7. [PMID: 26304411 DOI: 10.1016/j.foodchem.2015.07.079] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Revised: 07/04/2015] [Accepted: 07/20/2015] [Indexed: 12/24/2022]
Abstract
In the search for neuroactive compounds that mimic the nerve growth factor (NGF) activity for the protection against neurodegenerative diseases, the potential medicinal values of foods and plants attracts intense interest. Isofuranodiene is the major constituent of the essential oil of wild celery (Smyrnium olusatrum L., Apiaceae). The cytotoxic effects of isofuranodiene towards rat neuronal PC-12 pheochromocytoma cells were determined by MTT assay, while the cell differentiation was evaluated with xCELLigence real time cell analysis system (RTCA DP), and the neuritogenic activity was assessed by neurite outgrowth image analysis. Isofuranodiene at concentrations of 25 and 12.5 μM alone, or in combination with 50 nM NGF, showed a marked stimulation of neuritogenesis, but it was more effective at 12.5 μM with or without NGF. The present study reports the first evidence of the neuritogenic effects of isofuranodiene, which appears to be a promising neurotrophic and neuroprotective agent deserving further investigation.
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Affiliation(s)
- Ahmed M Mustafa
- School of Pharmacy, University of Camerino, Via Sant'Agostino 1, 62032 Camerino, Italy
| | - Filippo Maggi
- School of Pharmacy, University of Camerino, Via Sant'Agostino 1, 62032 Camerino, Italy.
| | - Fabrizio Papa
- School of Science and Technology, University of Camerino, Via Sant'Agostino 1, 62032 Camerino, Italy
| | - Elif Kaya
- Department of Pharmacology, Faculty of Pharmacy, Anadolu University, 26470 Eskisehir, Turkey
| | - Miris Dikmen
- Department of Pharmacology, Faculty of Pharmacy, Anadolu University, 26470 Eskisehir, Turkey
| | - Yusuf Öztürk
- Department of Pharmacology, Faculty of Pharmacy, Anadolu University, 26470 Eskisehir, Turkey
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Liu F, Zhang H, Zhang K, Wang X, Li S, Yin Y. Rapamycin promotes Schwann cell migration and nerve growth factor secretion. Neural Regen Res 2014; 9:602-9. [PMID: 25206862 PMCID: PMC4146242 DOI: 10.4103/1673-5374.130101] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/22/2014] [Indexed: 11/04/2022] Open
Abstract
Rapamycin, similar to FK506, can promote neural regeneration in vitro. We assumed that the mechanisms of action of rapamycin and FK506 in promoting peripheral nerve regeneration were similar. This study compared the effects of different concentrations of rapamycin and FK506 on Schwann cells and investigated effects and mechanisms of rapamycin on improving peripheral nerve regeneration. Results demonstrated that the lowest rapamycin concentration (1.53 nmol/L) more significantly promoted Schwann cell migration than the highest FK506 concentration (100μmol/L). Rapamycin promoted the secretion of nerve growth factors and upregulated growth-associated protein 43 expression in Schwann cells, but did not significantly affect Schwann cell proliferation. Therefore, rapamycin has potential application in peripheral nerve regeneration therapy.
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Affiliation(s)
- Fang Liu
- Department of Orthopedics, Second Hospital of Yueyang, Yueyang, Hunan Province, China
| | - Haiwei Zhang
- Department of Orthopedics, Second Hospital of Yueyang, Yueyang, Hunan Province, China
| | - Kaiming Zhang
- Department of Orthopedics, Second Hospital of Yueyang, Yueyang, Hunan Province, China
| | - Xinyu Wang
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, and Biomedical Materials and Engineering Center, Wuhan University of Technology, Wuhan, Hunan Province, China
| | - Shipu Li
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, and Biomedical Materials and Engineering Center, Wuhan University of Technology, Wuhan, Hunan Province, China
| | - Yixia Yin
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, and Biomedical Materials and Engineering Center, Wuhan University of Technology, Wuhan, Hunan Province, China
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Yin L, Ye S, Chen Z, Zeng Y. Rapamycin preconditioning attenuates transient focal cerebral ischemia/reperfusion injury in mice. Int J Neurosci 2012; 122:748-56. [PMID: 22901235 DOI: 10.3109/00207454.2012.721827] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Rapamycin, an mTOR inhibitor and immunosuppressive agent in clinic, has protective effects on traumatic brain injury and neurodegenerative diseases. But, its effects on transient focal ischemia/reperfusion disease are not very clear. In this study, we examined the effects of rapamycin preconditioning on mice treated with middle cerebral artery occlusion/reperfusion operation (MCAO/R). We found that the rapamycin preconditioning by intrahippocampal injection 20 hr before MCAO/R significantly improved the survival rate and longevity of mice. It also decreased the neurological deficit score, infracted areas and brain edema. In addition, rapamycin preconditioning decreased the production of NF-κB, TNF-α, and Bax, but not Bcl-2, an antiapoptotic protein in the ischemic area. From these results, we may conclude that rapamycin preconditioning attenuate transient focal cerebral ischemia/reperfusion injury and inhibits apoptosis induced by MCAO/R in mice.
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Affiliation(s)
- Lele Yin
- Institute of Tissue Transplantation and Immunology, Jinan University, Guangzhou, PR China
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12
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Stiegler NV, Krug AK, Matt F, Leist M. Assessment of Chemical-Induced Impairment of Human Neurite Outgrowth by Multiparametric Live Cell Imaging in High-Density Cultures. Toxicol Sci 2011; 121:73-87. [DOI: 10.1093/toxsci/kfr034] [Citation(s) in RCA: 96] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Biosynthesis of rapamycin and its regulation: past achievements and recent progress. J Antibiot (Tokyo) 2010; 63:434-41. [PMID: 20588302 DOI: 10.1038/ja.2010.71] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Rapamycin and its analogs are clinically important macrolide compounds produced by Streptomyces hygroscopicus. They exhibit antifungal, immunosuppressive, antitumor, neuroprotective and antiaging activities. The core macrolactone ring of rapamycin is biosynthesized by hybrid type I modular polyketide synthase (PKS)/nonribosomal peptide synthetase systems primed with 4,5-dihydrocyclohex-1-ene-carboxylic acid. The linear polyketide chain is condensed with pipecolate by peptide synthetase, followed by cyclization to form the macrolide ring and modified by a series of post-PKS tailoring steps. The aim of this review was to outline past and recent advances in the biosynthesis and regulation of rapamycin, with an emphasis on the distinguished contributions of Professor Demain to the study of rapamycin. In addition, this article describes the biological activities as well as mechanism of action of rapamycin and its derivatives. Recent attempts to improve the productivity of rapamycin and generate diverse rapamycin analogs through mutasynthesis and mutagenesis are also introduced, along with some future perspectives.
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14
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Lagoda G, Sezen SF, Burnett AL. FK506 and Rapamycin Neuroprotect Erection and Involve Different Immunophilins in a Rat Model of Cavernous Nerve Injury. J Sex Med 2009; 6:1914-23. [DOI: 10.1111/j.1743-6109.2009.01293.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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15
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Jin E, Sano M. Neurite outgrowth of NG108-15 cells induced by heat shock protein 90 inhibitors. Cell Biochem Funct 2009; 26:825-32. [PMID: 18636417 DOI: 10.1002/cbf.1458] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
We previously reported that radicicol (Rad) and geldanamycin (Geld), heat shock protein 90 (Hsp90) inhibitors, potentiate neurite growth of cultured sensory neurons from chick embryo. We now show that the antibiotics induce neurite growth in NG108-15 cells. Treatment of the cells with these drugs caused transient decrease in protein levels of Raf1, ERK1/2, phosphorylated ERK1/2, Akt1, and CDK4. The neurite growth of NG108-15 induced by the inhibitors was blocked by actynomycin D, but the neurite growth stimulated by dbcAMP in the cells was not affected. The neurite growth could be due to a change in the synthesis of some specific protein(s) and is speculated to be due to the transient downregulation of particular-signaling molecules stabilized by Hsp90.
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Affiliation(s)
- Erika Jin
- Department of Biology, Kyoto Prefectural University of Medicine, Kyoto 603-8334, Japan
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16
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Pan T, Kondo S, Zhu W, Xie W, Jankovic J, Le W. Neuroprotection of rapamycin in lactacystin-induced neurodegeneration via autophagy enhancement. Neurobiol Dis 2008; 32:16-25. [DOI: 10.1016/j.nbd.2008.06.003] [Citation(s) in RCA: 158] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2008] [Revised: 05/29/2008] [Accepted: 06/05/2008] [Indexed: 11/16/2022] Open
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17
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Liu D, McIlvain HB, Fennell M, Dunlop J, Wood A, Zaleska MM, Graziani EI, Pong K. Screening of immunophilin ligands by quantitative analysis of neurofilament expression and neurite outgrowth in cultured neurons and cells. J Neurosci Methods 2007; 163:310-20. [PMID: 17490751 DOI: 10.1016/j.jneumeth.2007.03.018] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2007] [Revised: 03/22/2007] [Accepted: 03/22/2007] [Indexed: 02/04/2023]
Abstract
Immunophilins are protein receptors for the immunosuppressant drugs FK506, cyclosporin A (CsA), and rapamycin. Two categories of immunophilins are the FK506-binding proteins (FKBPs), which bind to FK506, rapamycin, and CCI-779 and the cyclophilins, which bind to CsA. Reports have shown that immunophilins are expressed in the brain and spinal cord, are 10-100-fold higher in CNS tissue than immune tissue, and their expression is increased following nerve injury, suggesting that their chemical ligands may have therapeutic utility in the treatment of neurodegenerative diseases. In this study, we report the development and utility of a rapid neurofilament (NF) enzyme-linked immunosorbent assay (ELISA) to quantify neuronal survival and the Cellomics ArrayScan platform to quantify neurite outgrowth following treatment with immunophilin ligands. Cultured neurons or F-11 cells were treated with various immunophilin ligands for 72 or 96h and their promotion of neuronal survival and neurite outgrowth were determined. The results showed that all immunophilin ligands, in a concentration-dependent manner, significantly increased neuronal survival and neurite outgrowth, when compared to control cultures. Taken together, these results demonstrate the potential utility of the neurofilament ELISA and Cellomics ArrayScan platform to efficiently quantify neurotrophic effects of immunophilin ligands on cultured neurons and cell lines.
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Affiliation(s)
- Danni Liu
- Neuroscience Discovery Research, Wyeth Research, Princeton, NJ 08543, United States
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Alemdar AY, Sadi D, McAlister V, Mendez I. Intracerebral co-transplantation of liposomal tacrolimus improves xenograft survival and reduces graft rejection in the hemiparkinsonian rat. Neuroscience 2007; 146:213-24. [PMID: 17303340 DOI: 10.1016/j.neuroscience.2007.01.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2006] [Revised: 12/26/2006] [Accepted: 01/08/2007] [Indexed: 01/19/2023]
Abstract
Immunosuppression remains a key issue in neural transplantation. Systemic administration of cyclosporin-A is currently widely used but has many severe adverse side effects. Newer immunosuppressive agents, such as tacrolimus (TAC) and rapamycin (RAPA), have been investigated for their neuroprotective properties on dopaminergic neurons. These drugs have been formulated into liposomal preparations [liposomal tacrolimus (LTAC) and liposomal rapamycin (LRAPA)] which retain these neuroprotective properties. Due to the slower release of the drugs from the liposomes, we hypothesized that co-transplantation of either LTAC or LRAPA within a xenogeneic cell suspension would increase cell survival and decrease graft rejection in the hemiparkinsonian rat, and that a combination of the two drugs may have a synergistic effect. 6-hydroxydopamine-lesioned rats were divided to four groups which received intra-striatal transplants of the following: 1) a cell suspension containing 400,000 fetal mouse ventral mesencephalic cells; 2) the cell suspension containing 0.63 microM LRAPA; 3) the cell suspension containing a dose of 2.0 microM LTAC; 4) the cell suspension containing 2.0 microM LTAC and 0.63 microM LRAPA. Functional recovery was assessed by amphetamine-induced rotational behavior. Animals were killed at 4 days or 6 weeks post-transplantation, and immunohistochemistry was performed to look at the expression of tyrosine hydroxylase and major histocompatibility complex classes I and II. Only the group receiving LTAC had a decrease in rotational behavior. This observation correlated well with significantly more surviving tyrosine hydroxylase immunoreactive cells compared with the other groups and significantly lower levels of immunorejection as assessed by major histocompatibility complex class I and II staining. This study has shown the feasibility of using local immunosuppression in xenotransplantation. These findings may be useful in optimizing immunosuppression in experimental neural transplantation in the laboratory and its translation into the clinical setting.
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Affiliation(s)
- A Y Alemdar
- Neural Transplantation Laboratory, Department of Anatomy and Neurobiology, Dalhousie University, Halifax Infirmary, Nova Scotia, Canada B3H 3A7
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Hattori N, Nomoto H, Mishima S, Inagaki S, Goto M, Sako M, Furukawa S. Identification of AMP N1-oxide in royal jelly as a component neurotrophic toward cultured rat pheochromocytoma PC12 cells. Biosci Biotechnol Biochem 2006; 70:897-906. [PMID: 16636457 DOI: 10.1271/bbb.70.897] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
An extract of royal jelly (RJ) induced processes from cultured rat pheochromocytoma PC12 cells. Active components were isolated, and identified as adenosine monophosphate (AMP) and AMP N1-oxide. AMP N1-oxide was more than 20 times as active as AMP, judging from the minimal concentration to elicit activity. AMP N1-oxide was thought to be responsible for about half of the process-forming activity of whole RJ. Chemically-synthesized AMP N1-oxide was active similarly to the molecule purified from RJ, confirming AMP N1-oxide as the active entity. AMP N1-oxide also suppressed proliferation of PC12 cells and stimulated expression of neurofilament M, a specific protein of mature neurons, demonstrating the stimulatory activity of AMP N1-oxide to induce neuronal differentiation of PC12 cells. Pharmacological experiments suggested that AMP N1-oxide actions are mediated by adenyl cyclase-coupled adenosine receptors, including A2A. Thus AMP N1-oxide is a key molecule that characterizes RJ, and is not found in natural products other than RJ.
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Affiliation(s)
- Noriko Hattori
- Laboratory of Molecular Biology, Gifu Pharmaceutical University, Gifu, Japan
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20
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Edlich F, Fischer G. Pharmacological targeting of catalyzed protein folding: the example of peptide bond cis/trans isomerases. Handb Exp Pharmacol 2005:359-404. [PMID: 16610367 DOI: 10.1007/3-540-29717-0_15] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Peptide bond isomerases are involved in important physiological processes that can be targeted in order to treat neurodegenerative disease, cancer, diseases of the immune system, allergies, and many others. The folding helper enzyme class of Peptidyl-Prolyl-cis/trans Isomerases (PPIases) contains the three enzyme families of cyclophilins (Cyps), FK506 binding proteins (FKBPs), and parvulins (Pars). Although they are structurally unrelated, all PPIases catalyze the cis/trans isomerization of the peptide bond preceding the proline in a polypeptide chain. This process not only plays an important role in de novo protein folding, but also in isomerization of native proteins. The native state isomerization plays a role in physiological processes by influencing receptor ligand recognition or isomer-specific enzyme reaction or by regulating protein function by catalyzing the switch between native isomers differing in their activity, e.g., ion channel regulation. Therefore elucidating PPIase involvement in physiological processes and development of specific inhibitors will be a suitable attempt to design therapies for fatal and deadly diseases.
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Affiliation(s)
- F Edlich
- Max-Planck Research Unit for Enzymology of Protein Folding, Halle/Saale, Germany
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21
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Myckatyn TM, Mackinnon SE. Surgical techniques of nerve grafting (standard/vascularized/allograft). ACTA ACUST UNITED AC 2004. [DOI: 10.1053/j.oto.2004.06.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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22
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Munton RP, Vizi S, Mansuy IM. The role of protein phosphatase-1 in the modulation of synaptic and structural plasticity. FEBS Lett 2004; 567:121-8. [PMID: 15165904 DOI: 10.1016/j.febslet.2004.03.121] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2004] [Accepted: 03/24/2004] [Indexed: 12/14/2022]
Abstract
Synaptic plasticity is a phenomenon contributing to changes in the efficacy of neuronal transmission. These changes are widely believed to be a major cellular basis for learning and memory. Protein phosphorylation is a key biochemical process involved in synaptic plasticity that operates through a tight balance between the action of protein kinases and protein phosphatases (PPs). Although the majority of research in this field has concentrated primarily on protein kinases, the significant role of PPs is becoming increasingly apparent. This review examines one such phosphatase, PP1, and highlights recent advances in the understanding of its intervention in synaptic and structural plasticity and the mechanisms of learning and memory.
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Affiliation(s)
- Richard P Munton
- Department of Biology, HPM D24, ETH Hönggerberg, CH-8093 Zurich, Switzerland
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23
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Powers JF, Brachold JM, Schelling K, Tischler AS. Potentiation of mitogenesis in adult rat chromaffin cell cultures by immunosuppressive agent FK506. Neurosci Lett 2004; 356:5-8. [PMID: 14746888 DOI: 10.1016/j.neulet.2003.10.083] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The immunosuppressive drugs FK506 and cyclosporin inhibit T- and B-lymphocyte proliferation and exert neuritogenic and/or cytoprotective effects on several types of neurons. While the immunosuppressive actions of both drugs are mediated in large part by inhibition of the Ca(2+)-dependent phosphatase, calcineurin, FK506 is known to exert additional effects. In the present study, FK506 is shown to potentiate mitogenic effects of the neurotrophic factor, neurturin, on normal adult rat adrenal chromaffin cells in culture. The effect is not seen with cyclosporin or with a non-immunosuppressive analog of FK506, GPI-1046. The finding of increased mitogenesis in response to FK506 may have applications to the study of normal and neoplastic neuroendocrine cells and to understanding the development of some types of tumors in transplant patients.
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Affiliation(s)
- J F Powers
- Department of Pathology, Tufts New England Medical Center and Tufts University School of Medicine, Boston, MA 02111, USA.
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Li F, Omori N, Hayashi T, Jin G, Sato K, Nagano I, Shoji M, Abe K. Protection against ischemic brain damage in rats by immunophilin ligand GPI-1046. J Neurosci Res 2004; 76:383-9. [PMID: 15079867 DOI: 10.1002/jnr.20067] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
To determine the effect of immunophilin ligand GPI-1046 on ischemic brain injury, 90 min of transient middle cerebral artery occlusion (MCAO) was carried out in rat brains. In contrast to cases treated with vehicle, the infarct volume was reduced greatly and rotamase activity was inhibited significantly at 24 hr of reperfusion by treatment with GPI-1046. Immunoreactivity and the number of cells stained positively for FKBP12, FKBP52, caspase-8, cytochrome c, and caspase-3 were also reduced markedly in the brain after GPI-1046 treatment. The present results suggest that GPI-1046 significantly decreased infarct volume and provided neuroprotective effect on rats after transient focal cerebral ischemia by inhibiting the increase of rotamase activity and of the number of FKBP12-, FKBP52-, caspase-8-, cytochrome c-, and caspase-3-positive cells in the ischemic area.
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Affiliation(s)
- Feng Li
- Department of Neurology, Graduate School of Medicine and Dentistry, Okayama University, Okayama, Japan.
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25
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Khan Z, Ferrari G, Kasper M, Tonge DA, Steiner JP, Hamilton GS, Gordon-Weeks PR. The non-immunosuppressive immunophilin ligand GPI-1046 potently stimulates regenerating axon growth from adult mouse dorsal root ganglia cultured in Matrigel. Neuroscience 2002; 114:601-9. [PMID: 12220563 DOI: 10.1016/s0306-4522(02)00314-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We used explant cultures of adult mouse dorsal root ganglia with spinal nerve attached growing in Matrigel to assess the effects of the non-immunosuppressive immunophilin ligand GPI-1046 [Snyder et al. (1998) TIPS 19, 21-26] on the growth rate of regenerating sensory axons and found a potent stimulation of axon growth. In these explant cultures, naked, unfasciculated axons emerge from the cut end of the spinal nerve and continue to grow in the Matrigel for up to eight days [Tonge et al. (1996) Neuroscience 73, 541-551]. Some axons are entirely smooth whilst others show prominent varicosities. Some of the former express the phosphorylated neurofilament epitope recognised by monoclonal antibody RT97, a marker for large calibre, myelinated axons, whilst the latter express calcitonin gene-related peptide, predominantly a marker for unmyelinated, and small diameter myelinated sensory axons. Many of the axons in these cultures also express the low-affinity neurotrophin receptor p75. GPI-1046 has been shown to have striking stimulatory effects on embryonic primary sensory axons growing in vitro and it was therefore of interest to see whether it could also enhance regenerating sensory axon growth from the adult ganglia in our cultures. GPI-1046 potently stimulated axon growth in our cultures in a dose-dependent manner. The stimulatory effect was not dependent on the class of sensory axon. These observations show that GPI-1046 is a potent stimulator of regenerating axons from adult, primary sensory neurones. The cellular site of action of GPI-1046 is unknown. To distinguish between a direct effect of the drug on neurones and an indirect effect we compared the effects of GPI-1046 on explant and dissociated cultures. In confirmation of previous results, we found that GPI-1046 potently stimulated axon outgrowth from explants of embryonic chick dorsal root ganglia. However, the drug was without effect on dissociated embryonic dorsal root ganglion neurones, suggesting that non-neuronal cells are important for axon growth stimulation.
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Affiliation(s)
- Z Khan
- MRC Centre for Developmental Neurobiology, King's College London, Room 4.26B, New Hunts House, Guy's Campus, London SE1 1UL, UK
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Oliver CJ, Terry-Lorenzo RT, Elliott E, Bloomer WAC, Li S, Brautigan DL, Colbran RJ, Shenolikar S. Targeting protein phosphatase 1 (PP1) to the actin cytoskeleton: the neurabin I/PP1 complex regulates cell morphology. Mol Cell Biol 2002; 22:4690-701. [PMID: 12052877 PMCID: PMC133892 DOI: 10.1128/mcb.22.13.4690-4701.2002] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Neurabin I, a neuronal actin-binding protein, binds protein phosphatase 1 (PP1) and p70 ribosomal S6 protein kinase (p70S6K), both proteins implicated in cytoskeletal dynamics. We expressed wild-type and mutant neurabins fused to green fluorescent protein in Cos7, HEK293, and hippocampal neurons. Biochemical and cellular studies showed that an N-terminal F-actin-binding domain dictated neurabin I localization at actin cytoskeleton and promoted disassembly of stress fibers. Deletion of the C-terminal coiled-coil and sterile alpha motif domains abolished neurabin I dimerization and induced filopodium extension. Immune complex assays showed that neurabin I recruited an active PP1 via a PP1-docking sequence,(457)KIKF(460). Mutation of the PP1-binding motif or PP1 inhibition by okadaic acid and calyculin A abolished filopodia and restored stress fibers in cells expressing neurabin I. In vitro and in vivo studies suggested that the actin-binding domain attenuated protein kinase A (PKA) phosphorylation of neurabin I. Modification of a major PKA site, serine-461, impaired PP1 binding. Finally, p70S6K was excluded from neurabin I/PP1 complexes and required the displacement of PP1 for recruitment to neurabin I. These studies provided new insights into the assembly and regulation of a neurabin I/PP1 complex that controls actin rearrangement to promote spine development in mammalian neurons.
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Affiliation(s)
- Carey J Oliver
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710, USA
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27
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Myckatyn TM, Ellis RA, Grand AG, Sen SK, Lowe JB, Hunter DA, Mackinnon SE. The effects of rapamycin in murine peripheral nerve isografts and allografts. Plast Reconstr Surg 2002; 109:2405-17. [PMID: 12045568 DOI: 10.1097/00006534-200206000-00035] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The FKBP-12-binding ligand FK506 has been successfully used to stimulate nerve regeneration and prevent the rejection of peripheral nerve allografts. The immunosuppressant rapamycin, another FKBP-12-binding ligand, stimulates axonal regeneration in vitro, but its influence on nerve regeneration in peripheral nerve isografts or allografts has not been studied. Sixty female inbred BALB/cJ mice were randomized into six tibial nerve transplant groups, including three isograft and three allograft (C57BL/6J) groups. Grafts were left untreated (groups I and II), treated with FK506 (groups III and IV), or treated with rapamycin (groups V and VI). Nerve regeneration was quantified in terms of histomorphometry and functional recovery, and immunosuppression was confirmed with mixed lymphocyte reactivity assays. Animals treated with FK506 and rapamycin were immunosuppressed and demonstrated significantly less immune cell proliferation relative to untreated recipient animals. Although every animal demonstrated some functional recovery during the study, animals receiving an untreated peripheral nerve allograft were slowest to recover. Isografts treated with FK506 but not rapamycin demonstrated significantly increased nerve regeneration. Nerve allografts in animals treated with FK506, and to a lesser extent rapamycin, however, both demonstrated significantly more nerve regeneration and increased nerve fiber widths relative to untreated controls. The authors suggest that rapamycin can facilitate regeneration through peripheral nerve allografts, but it is not a neuroregenerative agent in this in vivo model. Nerve regeneration in FK506-treated peripheral nerve isografts and allografts was superior to that found in rapamycin-treated animals. Rapamycin may have a role in the treatment of peripheral nerve allografts when used in combination with other medications, or in the setting of renal failure that often precludes the use of calcineurin inhibitors such as FK506.
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Affiliation(s)
- Terence M Myckatyn
- Division of Plastic and Reconstructive Surgery, Washington University School of Medicine, One Barnes-Jewish Hospital Plaza, East Pavilion, St. Louis, MO 63110, USA
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Guo X, Dawson VL, Dawson TM. Neuroimmunophilin ligands exert neuroregeneration and neuroprotection in midbrain dopaminergic neurons. Eur J Neurosci 2001; 13:1683-93. [PMID: 11359520 DOI: 10.1046/j.0953-816x.2001.01542.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Immunosuppressant drugs, like FK506, and nonimmunosuppressant compounds like, GPI1046 and L685818, are immunophilin ligands that specifically bind to immunophilins, like FK506 binding protein 12 (FKBP12). Several lines of evidence show that these ligands exert neurotrophic properties in neural injury models and in PC12 cells. However, the mechanism of the neurotrophic function of the immunophilin ligands is poorly known. In the present study, we use MPP+ and 6-OHDA toxicity models to examine both neuroprotective and neuroregenerative effects of immunophilin ligands on primary cultures of midbrain dopaminergic neurons. We find that FK506, GPI1046 and L685818 at concentrations from 0.01 to 1 microM partially, but significantly, protect dopaminergic neurons against both MPP+ and 6-OHDA toxicity. By Western blot analysis, we also find that all three compounds prevent tyrosine hydroxylase (TH) loss induced by MPP+ and 6-OHDA treatments. Morphologic analysis of dopaminergic neurons, by immunocytochemistry, shows that MPP+ and 6-OHDA cause the retraction and loss of neuronal processes, while FK506, GPI1046 and L685818 promote regeneration of these processes as indicated by increases in process number and length. To examine if FKBP12 is required for neurotrophic effects of immunophilin ligands, we cultured dopaminergic neurons from FKBP12 knockout mice and find that FK506 still protects dopaminergic neurons against MPP+ toxicity. These results suggest that FKBP12 is not essential for the neurotrophic properties of immunophilin ligands, and immunophilin ligands are a new class of neuroprotective and neuroregenerative agents that may have therapeutic potential in a variety of neurological disorders.
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Affiliation(s)
- X Guo
- Department of Neurology, Johns Hopkins University School of Medicine, 600 N. Wolfe St., Carnegie 2-214, Baltimore, MD 21287, USA
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29
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Klettner A, Baumgrass R, Zhang Y, Fischer G, Bürger E, Herdegen T, Mielke K. The neuroprotective actions of FK506 binding protein ligands: neuronal survival is triggered by de novo RNA synthesis, but is independent of inhibition of JNK and calcineurin. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 2001; 97:21-31. [PMID: 11744159 DOI: 10.1016/s0169-328x(01)00286-8] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The immunosuppressant FK506 displays substantial neuroprotective and neuroregenerative effects. It is not fully understood to which extent these effects depend on the inhibition of the calcineurin phosphatase (PP2B). The present study has re-addressed this issue using Lie120, a novel highly specific inhibitor of calcineurin, which does not block the enzymatic activity of FKBPs or cyclophilins, respectively. We have determined the effect of FK506 (10-500 nM), V-10,367 (a FK506 derivative which does not block calcineurin; 1-5 microM) and Lie120 (a novel specific inhibitor of calcineurin, 0.1-5 microM) on the cellular survival and the pro-degenerative JNK activity of PC12 and Neuro2A cells following application of 200 microM H(2)O(2). FK506 and V-10,367, but not Lie120, protected both cell lines against H(2)O(2)-mediated death, whereas an increase in JNK1 activity was blocked by FK506 and Lie120, but not by V-10,367. Co-incubation of FK506 and V-10,367 with the mRNA synthesis inhibitor actinomycin D abolished the protective effect of FK506 and V-10,367. This antagonization was effective when actinomycin D was applied 30 min or 1 h, but not 2 or 4 h, after H(2)O(2) suggesting that FKBP-ligands confer their neuroprotection by rapid de novo synthesis of (functionally) anti-apoptotic proteins. The search for the corresponding effector genes revealed that the expression of FKBP25, FKBP38 and FKBP52 (analysis by reverse transcription-polymerase chain reaction (RT-PCR) did not change following H(2)O(2) or FK506, and this was also true for the expression of apoptosis-related genes caspase 3, bax, bcl-2 and bcl-xL (analysis by Multiplex-PCR). Summarizing, neuronal protection by FKBP-ligands is not mediated either by calcineurin or by JNK1 in this experimental set-up, whereas the FK506 mediated inhibition of JNK1 is realized by the inhibition of calcineurin, an effective activator of JNK1 in neurons.
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Affiliation(s)
- A Klettner
- Institute of Pharmacology, Christian-Albrechts-University, Hospitalstrasse 4, 24105, Kiel, Germany
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Guo X, Dillman JF, Dawson VL, Dawson TM. Neuroimmunophilins: novel neuroprotective and neuroregenerative targets. Ann Neurol 2001; 50:6-16. [PMID: 11456311 DOI: 10.1002/ana.1030] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Cyclosporin A (CsA) and FK506 (tacrolimus) are immunosuppresants that are widely used in organ transplantation. CsA is an 11-member cyclic peptide, whereas FK506 is a macrolide antibiotic. Recently, these powerful and useful compounds have become of great interest to neuroscientists for their unique neuroprotective and neuroregenerative effects. These drugs and nonimmunosuppressive analogs protect neurons from the effects of glutamate excitotoxicity, focal ischemia, and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced dopaminergic cell death. They also stimulate functional recovery of neurons in a variety of neurologic injury paradigms. These drugs exert their effects via immunophilins, the protein receptors for these agents. The immunophilin ligands show particular promise as a novel class of neuroprotective and neuroregenerative agents that have the potential to treat a variety of neurologic disorders.
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Affiliation(s)
- X Guo
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
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