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Sinha A, Katyal S, Kauppinen TM. PARP-DNA trapping ability of PARP inhibitors jeopardizes astrocyte viability: Implications for CNS disease therapeutics. Neuropharmacology 2021; 187:108502. [PMID: 33631119 DOI: 10.1016/j.neuropharm.2021.108502] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 01/29/2021] [Accepted: 02/16/2021] [Indexed: 12/21/2022]
Abstract
There is emerging interest in the role of poly(ADP-ribose) polymerase-1 (PARP-1) in neurodegeneration and potential of its therapeutic targeting in neurodegenerative disorders. New generations of PARP inhibitors exhibit polypharmacological properties; they do not only block enzymatic activity with lower doses, but also alter how PARP-1 interacts with DNA. While these new inhibitors have proven useful in cancer therapy due to their ability to kill cancer cell, their use in neurodegenerative disorders has an opposite goal: cell protection. We hypothesize that newer generation PARP-1 inhibitors jeopardize the viability of dividing CNS cells by promoting DNA damage upon the PARP-DNA interaction. Using enriched murine astrocyte cultures, our study evaluates the effects of a variety of drugs known to inhibit PARP; talazoparib, olaparib, PJ34 and minocycline. Despite similar PARP enzymatic inhibiting activities, we show here that these drugs result in varied cell viability. Talazoparib and olaparib reduce astrocyte growth in a dose-dependent manner, while astrocytes remain unaffected by PJ34 and minocycline. Similarly, PJ34 and minocycline do not jeopardize DNA integrity, while treatment with talazoparib and olaparib promote DNA damage. These two drugs impact astrocytes similarly in basal conditions and upon nitrosative stress, a pathological condition typical for neurodegeneration. Mechanistic assessment revealed that talazoparib and olaparib promote PARP trapping onto DNA in a dose-dependent manner, while PJ34 and minocycline do not induce PARP-DNA trapping. This study provides unique insight into the selective use of PARP inhibitors to treat neurodegenerative disorders whereby inhibition of PARP enzymatic activity must occur without deleteriously trapping PARP onto DNA.
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Affiliation(s)
- Asha Sinha
- Department of Pharmacology & Therapeutics, Max Rady College of Medicine, University of Manitoba, 753 McDermot Avenue, Winnipeg, Manitoba, R3E 0T6, Canada; Research Institute in Oncology and Hematology, CancerCare Manitoba, 675 McDermot Ave, RM ON5010, Winnipeg, Manitoba, R3E0V9, Canada; Kleysen Institute for Advance Medicine, Health Sciences Centre, 710 William Avenue, Winnipeg, Manitoba, R3E 0Z3, Canada.
| | - Sachin Katyal
- Department of Pharmacology & Therapeutics, Max Rady College of Medicine, University of Manitoba, 753 McDermot Avenue, Winnipeg, Manitoba, R3E 0T6, Canada; Research Institute in Oncology and Hematology, CancerCare Manitoba, 675 McDermot Ave, RM ON5010, Winnipeg, Manitoba, R3E0V9, Canada.
| | - Tiina M Kauppinen
- Department of Pharmacology & Therapeutics, Max Rady College of Medicine, University of Manitoba, 753 McDermot Avenue, Winnipeg, Manitoba, R3E 0T6, Canada; Kleysen Institute for Advance Medicine, Health Sciences Centre, 710 William Avenue, Winnipeg, Manitoba, R3E 0Z3, Canada.
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Cuprizone-Dependent De/Remyelination Responses and Functional Correlates in Mouse Strains Adopted to Model Relapsing, Chronic and Progressive Experimental Autoimmune Encephalomyelitis. Neurotox Res 2021; 39:658-666. [PMID: 33475965 PMCID: PMC8096768 DOI: 10.1007/s12640-021-00331-3] [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: 07/30/2020] [Revised: 12/31/2020] [Accepted: 01/05/2021] [Indexed: 11/20/2022]
Abstract
NOD mice represent a unique strain that recapitulates some aspects of progressive MS when subjected to experimental autoimmune encephalomyelitis (EAE). It is unknown, however, whether a proneness to demyelination and/or defect in remyelination contribute to disease progression in NOD mice. Answering to this question might help deciphering the molecular and cellular events underpinning disease evolution in progressive MS. Here, we compared the cuprizone-dependent demyelination and remyelination responses, as well as their functional correlates, in NOD, C57BL/6, and SJL mice typically adopted to model progressive, chronic or relapsing EAE. We report that demyelination occurred to a similar extent in the three mice strains, and that in none of them there was evidence of axonal degeneration during prolonged demyelination. Moreover, immunostaining for GFAP+ astrocytes, Iba1+ microglia, and NG2+ oligodendrocyte precursor cells similarly increased in the 3 mouse strains after cuprizone exposure. The mice underwent concomitant and complete remyelination 2 weeks after cuprizone withdrawal. On a functional level, NOD mice showed the earliest reduction of spontaneous motility and full recovery, but no impairment of motor skill. Conversely, C57BL/6 animals showed phasic reduction of both spontaneous motility and motor skill. Lastly, SJL mice presented the most severe neurological impairment with long-lasting reduction of spontaneous motility and motor skill. Overall, data suggest that the unique feature of EAE progression in NOD mice is not due to proneness to demyelination or intrinsic defects in myelin formation. Findings also unravel important functional differences in the response of the three mouse stains to cuprizone that can be harnessed to design and interpret future experiments.
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Buonvicino D, Ranieri G, Pratesi S, Gerace E, Muzzi M, Guasti D, Tofani L, Chiarugi A. Neuroprotection induced by dexpramipexole delays disease progression in a mouse model of progressive multiple sclerosis. Br J Pharmacol 2020; 177:3342-3356. [PMID: 32199028 DOI: 10.1111/bph.15058] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 03/11/2020] [Accepted: 03/13/2020] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND AND PURPOSE Drugs able to counteract progressive multiple sclerosis (MS) represent a largely unmet therapeutic need. Even though the pathogenesis of disease evolution is still obscure, accumulating evidence indicates that mitochondrial dysfunction plays a causative role in neurodegeneration and axonopathy in progressive MS patients. Here, we investigated the effects of dexpramipexole, a compound with a good safety profile in humans and able to sustain mitochondria functioning and energy production, in a mouse model of progressive MS. EXPERIMENTAL APPROACH Female non-obese diabetic mice were immunized with MOG35-55 . Functional, immune and neuropathological parameters were analysed during disease evolution in animals treated or not with dexpramipexole. The compound's effects on bioenergetics and neuroprotection were also evaluated in vitro. KEY RESULTS We found that oral treatment with dexpramipexole at a dose consistent with that well tolerated in humans delayed disability progression, extended survival, counteracted reduction of spinal cord mitochondrial DNA content and reduced spinal cord axonal loss of mice. Accordingly, the drug sustained in vitro bioenergetics of mouse optic nerve and dorsal root ganglia and counteracted neurodegeneration of organotypic mouse cortical cultures exposed to the adenosine triphosphate-depleting agents oligomycin or veratridine. Dexpramipexole, however, was unable to affect the adaptive and innate immune responses both in vivo and in vitro. CONCLUSION AND IMPLICATION The present findings corroborate the hypothesis that neuroprotective agents may be of relevance to counteract MS progression and disclose the translational potential of dexpramipexole to treatment of progressive MS patients as a stand-alone or adjunctive therapy.
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Affiliation(s)
- Daniela Buonvicino
- Department of Health Sciences, Section of Clinical Pharmacology and Oncology, University of Florence, Florence, Italy
| | - Giuseppe Ranieri
- Department of Health Sciences, Section of Clinical Pharmacology and Oncology, University of Florence, Florence, Italy
| | - Sara Pratesi
- Centre of Immunological Research DENOTHE, Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Elisabetta Gerace
- Section of Pharmacology and Toxicology, Department of Neuroscience, Psychology, Drug Research and Child Health (NeuroFarBa), University of Florence, Florence, Italy
| | - Mirko Muzzi
- Department of Health Sciences, Section of Clinical Pharmacology and Oncology, University of Florence, Florence, Italy
| | - Daniele Guasti
- Department of Clinical and Experimental Medicine, Research Unit of Histology & Embryology, University of Florence, Florence, Italy
| | - Lorenzo Tofani
- Clinical Trials Coordinating Center of Istituto Toscano Tumori, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
| | - Alberto Chiarugi
- Department of Health Sciences, Section of Clinical Pharmacology and Oncology, University of Florence, Florence, Italy
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Buonvicino D, Ranieri G, Pratesi S, Guasti D, Chiarugi A. Neuroimmunological characterization of a mouse model of primary progressive experimental autoimmune encephalomyelitis and effects of immunosuppressive or neuroprotective strategies on disease evolution. Exp Neurol 2019; 322:113065. [PMID: 31536728 DOI: 10.1016/j.expneurol.2019.113065] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 09/05/2019] [Accepted: 09/15/2019] [Indexed: 12/17/2022]
Abstract
Progressive multiple sclerosis (PMS) is a devastating disorder sustained by neuroimmune interactions still wait to be identified. Recently, immune-independent, neural bioenergetic derangements have been hypothesized as causative of neurodegeneration in PMS patients. To gather information on the immune and neurodegenerative components during PMS, in the present study we investigated the molecular and cellular events occurring in a Non-obese diabetic (NOD) mouse model of experimental autoimmune encephalomyelitis (EAE). In these mice, we also evaluated the effects of clinically-relevant immunosuppressive (dexamethasone) or bioenergetic drugs (bezafibrate and biotin) on functional, immune and neuropathological parameters. We found that immunized NOD mice progressively accumulated disability and severe neurodegeneration in the spinal cord. Unexpectedly, although CD4 and CD8 lymphocytes but not B or NK cells infiltrate the spinal cord linearly with time, their suppression by different dexamethasone treatment schedules did not affect disease progression. Also, the spreading of the autoimmune response towards additional immunogenic myelin antigen occurred neither in the periphery nor in the CNS of EAE mice. Conversely, we found that altered mitochondrial morphology, reduced contents of mtDNA and decreased transcript levels for respiratory complex subunits occurred at early disease stages and preceded axonal degeneration within spinal cord columns. However, the mitochondria boosting drugs, bezafibrate and biotin, were unable to reduce disability progression. Data suggest that EAE NOD mice recapitulate some features of PMS. Also, by showing that bezafibrate or biotin do not affect progression in NOD mice, our study suggests that this model can be harnessed to anticipate experimental information of relevance to innovative treatments of PMS.
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Affiliation(s)
- Daniela Buonvicino
- Department of Health Sciences, Section of Clinical Pharmacology and Oncology, University of Florence, Florence, Italy.
| | - Giuseppe Ranieri
- Department of Health Sciences, Section of Clinical Pharmacology and Oncology, University of Florence, Florence, Italy
| | - Sara Pratesi
- Centre of Immunological Research DENOTHE, Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Daniele Guasti
- Department of Clinical and Experimental Medicine, Research Unit of Histology & Embryology, University of Florence, Florence, Italy
| | - Alberto Chiarugi
- Department of Health Sciences, Section of Clinical Pharmacology and Oncology, University of Florence, Florence, Italy
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Kuo R, Saito E, Miller SD, Shea LD. Peptide-Conjugated Nanoparticles Reduce Positive Co-stimulatory Expression and T Cell Activity to Induce Tolerance. Mol Ther 2017; 25:1676-1685. [PMID: 28408181 PMCID: PMC5498812 DOI: 10.1016/j.ymthe.2017.03.032] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 03/21/2017] [Accepted: 03/22/2017] [Indexed: 12/11/2022] Open
Abstract
Targeted approaches to treat autoimmune diseases would improve upon current therapies that broadly suppress the immune system and lead to detrimental side effects. Antigen-specific tolerance was induced using poly(lactide-co-glycolide) nanoparticles conjugated with disease-relevant antigen to treat a model of multiple sclerosis. Increasing the nanoparticle dose and amount of conjugated antigen both resulted in more durable immune tolerance. To identify active tolerance mechanisms, we investigated downstream cellular and molecular events following nanoparticle internalization by antigen-presenting cells. The initial cell response to nanoparticles indicated suppression of inflammatory signaling pathways. Direct and functional measurement of surface MHC-restricted antigen showed positive correlation with both increasing particle dose from 1 to 100 μg/mL and increasing peptide conjugation by 2-fold. Co-stimulatory analysis of cells expressing MHC-restricted antigen revealed most significant decreases in positive co-stimulatory molecules (CD86, CD80, and CD40) following high doses of nanoparticles with higher peptide conjugation, whereas expression of a negative co-stimulatory molecule (PD-L1) remained high. T cells isolated from mice immunized against myelin proteolipid protein (PLP139-151) were co-cultured with antigen-presenting cells administered PLP139-151-conjugated nanoparticles, which resulted in reduced T cell proliferation, increased T cell apoptosis, and a stronger anti-inflammatory response. These findings indicate several potential mechanisms used by peptide-conjugated nanoparticles to induce antigen-specific tolerance.
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MESH Headings
- Animals
- Antigen-Presenting Cells/drug effects
- Antigen-Presenting Cells/immunology
- Antigen-Presenting Cells/pathology
- Antigens/chemistry
- Antigens/immunology
- Antigens/pharmacology
- B7-1 Antigen/genetics
- B7-1 Antigen/immunology
- B7-2 Antigen/genetics
- B7-2 Antigen/immunology
- CD40 Antigens/genetics
- CD40 Antigens/immunology
- Delayed-Action Preparations/administration & dosage
- Delayed-Action Preparations/chemistry
- Encephalomyelitis, Autoimmune, Experimental/genetics
- Encephalomyelitis, Autoimmune, Experimental/immunology
- Encephalomyelitis, Autoimmune, Experimental/pathology
- Encephalomyelitis, Autoimmune, Experimental/therapy
- Female
- Gene Expression
- Immune Tolerance/drug effects
- Immunoconjugates/chemistry
- Immunoconjugates/metabolism
- Immunoconjugates/pharmacology
- Mice
- Mice, Inbred C57BL
- Myelin Proteolipid Protein/chemistry
- Myelin Proteolipid Protein/immunology
- Myelin Proteolipid Protein/pharmacology
- Nanoparticles/administration & dosage
- Nanoparticles/chemistry
- Ovalbumin/chemistry
- Ovalbumin/immunology
- Ovalbumin/pharmacology
- Particle Size
- Polyglactin 910/chemistry
- Polyglactin 910/metabolism
- Primary Cell Culture
- Spleen/drug effects
- Spleen/immunology
- Spleen/pathology
- T-Lymphocytes, Regulatory/drug effects
- T-Lymphocytes, Regulatory/immunology
- T-Lymphocytes, Regulatory/pathology
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Affiliation(s)
- Robert Kuo
- Department of Chemical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - Eiji Saito
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - Stephen D Miller
- Department of Microbiology-Immunology, Northwestern University, Chicago, IL 60611, USA
| | - Lonnie D Shea
- Department of Chemical Engineering, University of Michigan, Ann Arbor, MI 48109, USA; Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA.
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Shao BZ, Ke P, Xu ZQ, Wei W, Cheng MH, Han BZ, Chen XW, Su DF, Liu C. Autophagy Plays an Important Role in Anti-inflammatory Mechanisms Stimulated by Alpha7 Nicotinic Acetylcholine Receptor. Front Immunol 2017; 8:553. [PMID: 28559895 PMCID: PMC5432615 DOI: 10.3389/fimmu.2017.00553] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 04/25/2017] [Indexed: 12/14/2022] Open
Abstract
Alpha7 nicotinic acetylcholine receptor (α7nAChR) has been reported to alleviate neuroinflammation. Here, we aimed to determine the role of autophagy in α7nAChR-mediated inhibition of neuroinflammation and its underlying mechanism. Experimental autoimmune encephalomyelitis (EAE) mice and lipopolysaccharide-stimulated BV2 microglia were used as in vivo and in vitro models of neuroinflammation, respectively. The severity of EAE was evaluated with neurological scoring. Autophagy-related proteins (Beclin 1, LC3-II/I, p62/SQSTM1) were detected by immunoblot. Autophagosomes were observed using transmission electron microscopy and tandem fluorescent mRFP-GFP-LC3 plasmid was applied to test autophagy flux. The mRNA levels of interleukin-6 (IL-6), IL-1β, IL-18, and tumor necrosis factor-α (TNF-α) were detected by real-time PCR. We used 3-methyladenine (3-MA) and autophagy-related gene 5 small interfering RNA (Atg5 siRNA) to block autophagy in vivo and in vitro, respectively. Activating α7nAChR with PNU282987 ameliorates EAE severity and spinal inflammatory infiltration in EAE mice. PNU282987 treatment also enhanced monocyte/microglia autophagy (Beclin 1, LC3-II/I ratio, p62/SQSTM1, colocalization of CD45- or CD68-positive cells with LC3) both in spinal cord and spleen from EAE mice. The beneficial effects of PNU282987 on EAE mice were partly abolished by 3-MA, an autophagy inhibitor. In vitro, PNU282987 treatment increased autophagy and promoted autophagy flux. Blockade of autophagy by Atg5 siRNA or bafilomycin A1 attenuated the inhibitory effect of PNU282987 on IL-6, IL-1β, IL-18, and TNF-α mRNA. Our results demonstrate for the first time that activating α7nAChR enhances monocyte/microglia autophagy, which suppresses neuroinflammation and thus plays an alleviative role in EAE.
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Affiliation(s)
- Bo-Zong Shao
- Department of Pharmacology, Second Military Medical University, Shanghai, China
| | - Ping Ke
- Department of Pharmacology, Second Military Medical University, Shanghai, China
| | - Zhe-Qi Xu
- Department of Pharmacology, Second Military Medical University, Shanghai, China
| | - Wei Wei
- Institute of Quality and Standard for Agro-Products, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Ming-He Cheng
- Department of Pharmacology, Second Military Medical University, Shanghai, China
| | - Bin-Ze Han
- Department of Pharmacology, Second Military Medical University, Shanghai, China
| | - Xiong-Wen Chen
- Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, PA, USA
| | - Ding-Feng Su
- Department of Pharmacology, Second Military Medical University, Shanghai, China
| | - Chong Liu
- Department of Pharmacology, Second Military Medical University, Shanghai, China
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Bhise V, Dhib-Jalbut S. Further understanding of the immunopathology of multiple sclerosis: impact on future treatments. Expert Rev Clin Immunol 2016; 12:1069-89. [PMID: 27191526 DOI: 10.1080/1744666x.2016.1191351] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
INTRODUCTION The understanding of the immunopathogenesis of multiple sclerosis (MS) has expanded with more research into T-cell subtypes, cytokine contributors, B-cell participation, mitochondrial dysfunction, and more. Treatment options have rapidly expanded with three relatively recent oral therapy alternatives entering the arena. AREAS COVERED In the following review, we discuss current mechanisms of immune dysregulation in MS, how they relate to current treatments, and the impact these findings will have on the future of therapy. Expert commentary: The efficacy of these medications and understanding their mechanisms of actions validates the immunopathogenic mechanisms thought to underlie MS. Further research has exposed new targets, while new promising therapies have shed light on new aspects into the pathophysiology of MS.
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Affiliation(s)
- Vikram Bhise
- a Rutgers Biomedical and Health Sciences - Departments of Pediatrics , Robert Wood Johnson Medical School , New Brunswick , NJ , USA
| | - Suhayl Dhib-Jalbut
- b Rutgers Biomedical and Health Sciences - Departments of Neurology , Robert Wood Johnson Medical School , New Brunswick , NJ , USA
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Abstract
PURPOSE OF REVIEW Recent studies indicate a role for immune dysregulation in the pathogenesis of multiple sclerosis, an inflammatory demyelinating and degenerative disease of the central nervous system. This review addresses the current mechanisms of immune dysregulation in the development of multiple sclerosis, including the impact of environmental risk factors on immunity in both multiple sclerosis and its animal models. RECENT FINDINGS CD4 T-helper (Th) cells have long been implicated as the main drivers of pathogenesis of multiple sclerosis. However, current studies indicate that multiple sclerosis is largely a heterogeneous disease process, which involves both innate and adaptive immune-mediated inflammatory mechanisms that ultimately contribute to demyelination and neurodegeneration. Therefore, B cells, CD8 T cells, and microglia/macrophages can also play an important role in the immunopathogenesis of multiple sclerosis apart from proinflammatory CD4 Th1/Th17 cell subsets. Furthermore, increasing evidence indicates that environmental risk factors, such as Vitamin D deficiency, Epstein-Barr virus, smoking, Western diet, and the commensal microbiota, influence the development of multiple sclerosis through interactions with genetic variants of multiple sclerosis, thus leading to the dysregulation of immune responses. SUMMARY A better understanding of immune-mediated mechanisms in the pathogenesis of multiple sclerosis and the contribution of environmental risk factors toward the development of multiple sclerosis will help further improve therapeutic approaches to prevent disease progression.
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Cavone L, Felici R, Lapucci A, Buonvicino D, Pratesi S, Muzzi M, Hakiki B, Maggi L, Peruzzi B, Caporale R, Annunziato F, Amato MP, Chiarugi A. Dysregulation of sphingosine 1 phosphate receptor-1 (S1P1) signaling and regulatory lymphocyte-dependent immunosuppression in a model of post-fingolimod MS rebound. Brain Behav Immun 2015; 50:78-86. [PMID: 26130058 DOI: 10.1016/j.bbi.2015.06.019] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 06/22/2015] [Accepted: 06/24/2015] [Indexed: 10/24/2022] Open
Abstract
Fingolimod affords protection from MS by sequestering lymphocytes in secondary lymphoid organs via down regulation of their sphingosine 1 phosphate receptor (S1P1). Unexpectedly, accumulating evidence indicates that patients who discontinue fingolimod treatment may be at risk of rehearsal of magnetic resonance (MR) and clinical disease activity, sometimes featuring dramatic rebound. We therefore developed in vivo and in vitro models of post-fingolimod MS rebound to unravel its cellular and molecular mechanisms. The impact of fingolimod withdrawal on T regulatory lymphocytes was also investigated by means of cytofluorimetric analysis and antigen-specific lymphocyte proliferation assays. We show that mice with relapsing-remitting experimental autoimmune encephalomyelitis (EAE) undergo extremely severe, chronic disease rebound upon discontinuation of fingolimod. Remarkably, rebound is preceded by a burst of S1P1 overexpression in lymph node-entrapped lymphocytes that correlates with subsequent massive lymphocyte egress and widespread CNS immune infiltration. Also, consistent with the ability of S1P1 to counteract polarization and function of T regulatory lymphocytes their number and suppression of effector T cells is reduced by fingolimod suspension. Data disclose the first pathogenic mechanisms of post-fingolimod rebound that may be targeted for therapeutic intervention.
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Affiliation(s)
- Leonardo Cavone
- Headache Center and Clinical Pharmacology Unit, Department of Health Sciences, Careggi University Hospital, Italy; Pharmacology and Oncology Unit, Department of Health Sciences, University of Florence, Italy.
| | - Roberta Felici
- Pharmacology and Oncology Unit, Department of Health Sciences, University of Florence, Italy
| | - Andrea Lapucci
- Pharmacology and Oncology Unit, Department of Health Sciences, University of Florence, Italy
| | - Daniela Buonvicino
- Pharmacology and Oncology Unit, Department of Health Sciences, University of Florence, Italy
| | - Sara Pratesi
- Department of Experimental and Clinical Medicine and DENOTHE Center, University of Florence, Florence 50134, Italy; Regenerative Medicine Unit of Azienda Ospedaliera Careggi, Italy
| | - Mirko Muzzi
- Pharmacology and Oncology Unit, Department of Health Sciences, University of Florence, Italy
| | - Bahia Hakiki
- Department NEUROFARBA, Section Neurosciences, University of Florence, Italy
| | - Laura Maggi
- Department of Experimental and Clinical Medicine and DENOTHE Center, University of Florence, Florence 50134, Italy; Regenerative Medicine Unit of Azienda Ospedaliera Careggi, Italy
| | - Benedetta Peruzzi
- General Laboratory Unit (Microscopy and Clinical Cytometry Unit), Careggi University Hospital, Italy
| | - Roberto Caporale
- General Laboratory Unit (Microscopy and Clinical Cytometry Unit), Careggi University Hospital, Italy
| | - Francesco Annunziato
- Department of Experimental and Clinical Medicine and DENOTHE Center, University of Florence, Florence 50134, Italy; Regenerative Medicine Unit of Azienda Ospedaliera Careggi, Italy
| | - Maria Pia Amato
- Department NEUROFARBA, Section Neurosciences, University of Florence, Italy
| | - Alberto Chiarugi
- Headache Center and Clinical Pharmacology Unit, Department of Health Sciences, Careggi University Hospital, Italy; Pharmacology and Oncology Unit, Department of Health Sciences, University of Florence, Italy
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Shao BZ, Wei W, Ke P, Xu ZQ, Zhou JX, Liu C. Activating cannabinoid receptor 2 alleviates pathogenesis of experimental autoimmune encephalomyelitis via activation of autophagy and inhibiting NLRP3 inflammasome. CNS Neurosci Ther 2015; 20:1021-8. [PMID: 25417929 DOI: 10.1111/cns.12349] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 10/08/2014] [Accepted: 10/08/2014] [Indexed: 12/15/2022] Open
Abstract
AIMS Activation of cannabinoid receptor 2 (CB2R) has been reported to ameliorate the pathogenesis of experimental autoimmune encephalomyelitis (EAE). In this study, we examined whether autophagy is involved in the beneficial effect of CB2R on EAE and explored the mechanism with a focus on inflammasome activation. METHODS EAE severity was analyzed with clinical score and histological score stained by hematoxylin and eosin or luxol fast blue in spinal cord. Immunoblot analysis was conducted to detect proteins of NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome-related caspase-1 (Casp-1) and the maturation of interleukin (IL)-1β as well as autophagy-related light chain 3 (LC3), and Beciln 1 both in vivo and in vitro. Reverse transcription and real-time PCR were used to detect mRNA of NLRP3, IL-1β and Casp-1. Autophagy-related gene 5 (ATG5)-specific siRNA was transiently transfected in BV2 microglia, and immunofluorescence staining was carried out to detect the expression of NLRP3, caspase recruitment domain (ASC), and pro-caspase-1. RESULTS The current data indicated that deleting CB2R decreased the expression of LC3-II/LC3-I ratio, Beclin 1 and increased caspase-1 activation and IL-1β production in the spinal cord of EAE mice, whereas activation of CB2R with a specific agonist HU-308 induced inverse effects. Further study indicated that HU-308 could promote autophagy and inhibit expression and activation of NLRP3 inflammasome in BV2 microglia. Blocking autophagy by ATG5-specific siRNA dismissed the effort of CB2R in mediating NLRP3 inflammasome in vitro. CONCLUSION Collectively, our results demonstrated for the first time that CB2R plays a protective role in EAE through promoting autophagy and inhibiting NLRP3 inflammasome activation.
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Affiliation(s)
- Bo-Zong Shao
- Department of Pharmacology, Second Military Medical University, Shanghai, China
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