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Tiwari RK, Moin A, Rizvi SMD, Shahid SMA, Bajpai P. Modulating neuroinflammation in neurodegeneration-related dementia: can microglial toll-like receptors pull the plug? Metab Brain Dis 2021; 36:829-847. [PMID: 33704660 DOI: 10.1007/s11011-021-00696-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 02/16/2021] [Indexed: 01/13/2023]
Abstract
Neurodegeneration-associated dementia disorders (NADDs), namely Alzheimer and Parkinson diseases, are developed by a significant portion of the elderly population globally. Extensive research has provided critical insights into the molecular basis of the pathological advancements of these diseases, but an efficient curative therapy seems elusive. A common attribute of NADDs is neuroinflammation due to a chronic inflammatory response within the central nervous system (CNS), which is primarily modulated by microglia. This response within the CNS is positively regulated by cytokines, chemokines, secondary messengers or cyclic nucleotides, and free radicals. Microglia mediated immune activation is regulated by a positive feedback loop in NADDs. The present review focuses on evaluating the crosstalk between inflammatory mediators and microglia, which aggravates both the clinical progression and extent of NADDs by forming a persistent chronic inflammatory milieu within the CNS. We also discuss the role of the human gut microbiota and its effect on NADDs as well as the suitability of targeting toll-like receptors for an immunotherapeutic intervention targeting the deflation of an inflamed milieu within the CNS.
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Affiliation(s)
- Rohit Kumar Tiwari
- Department of Biosciences, Integral University, Kursi Road, Lucknow, Uttar Pradesh, 226026, India
| | - Afrasim Moin
- Department of Pharmaceutics, College of Pharmacy, University of Hail, Hail, Kingdom of Saudi Arabia
| | - Syed Mohd Danish Rizvi
- Department of Pharmaceutics, College of Pharmacy, University of Hail, Hail, Kingdom of Saudi Arabia
| | - Syed Monowar Alam Shahid
- Department of Biochemistry, College of Medicine, University of Hail, Hail, Kingdom of Saudi Arabia
| | - Preeti Bajpai
- Department of Zoology, School of Life Sciences, Mahatma Gandhi Central University, Motihari, Bihar, 845401, India.
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2
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Policastro G, Brunelli M, Tinazzi M, Chiamulera C, Emerich DF, Paolone G. Cytokine-, Neurotrophin-, and Motor Rehabilitation-Induced Plasticity in Parkinson's Disease. Neural Plast 2020; 2020:8814028. [PMID: 33293946 PMCID: PMC7714573 DOI: 10.1155/2020/8814028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 11/06/2020] [Accepted: 11/19/2020] [Indexed: 02/06/2023] Open
Abstract
Neuroinflammation and cytokine-dependent neurotoxicity appear to be major contributors to the neuropathology in Parkinson's disease (PD). While pharmacological advancements have been a mainstay in the treatment of PD for decades, it is becoming increasingly clear that nonpharmacological approaches including traditional and nontraditional forms of exercise and physical rehabilitation can be critical adjunctive or even primary treatment avenues. Here, we provide an overview of preclinical and clinical research detailing the biological role of proinflammatory molecules in PD and how motor rehabilitation can be used to therapeutically modulate neuroinflammation, restore neural plasticity, and improve motor function in PD.
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Affiliation(s)
| | - Matteo Brunelli
- Department of Diagnostic and Public Health, University of Verona, Verona, Italy
| | - Michele Tinazzi
- Department of Neuroscience, Biomedicine and Movement, University of Verona, Verona, Italy
| | | | | | - Giovanna Paolone
- Department of Diagnostic and Public Health, University of Verona, Verona, Italy
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3
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Angelopoulou E, Paudel YN, Shaikh MF, Piperi C. Fractalkine (CX3CL1) signaling and neuroinflammation in Parkinson’s disease: Potential clinical and therapeutic implications. Pharmacol Res 2020; 158:104930. [DOI: 10.1016/j.phrs.2020.104930] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 04/16/2020] [Accepted: 05/12/2020] [Indexed: 12/14/2022]
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TNF inhibits catecholamine production from induced sympathetic neuron-like cells in rheumatoid arthritis and osteoarthritis in vitro. Sci Rep 2018; 8:9645. [PMID: 29941879 PMCID: PMC6018168 DOI: 10.1038/s41598-018-27927-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 06/11/2018] [Indexed: 12/19/2022] Open
Abstract
Synovial adipose stem cells (sASC) can be differentiated into catecholamine-expressing sympathetic neuron-like cells to treat experimental arthritis. However, the pro-inflammatory tumor necrosis factor (TNF) is known to be toxic to catecholaminergic cells (see Parkinson disease), and this may prevent anti-inflammatory effects in inflamed tissue. We hypothesized that TNF exhibits inhibitory effects on human differentiated sympathetic tyrosine hydroxylase-positive (TH+) neuron-like cells. For the first time, iTH+ neuron-like sympathetic cells were generated from sACSs of rheumatoid arthritis (RA) and osteoarthritis (OA) synovial tissue. Compared to untreated controls in both OA and RA, TNF-treated iTH+ cells demonstrated a weaker staining of catecholaminergic markers in cell cultures of RA/OA patients, and the amount of produced noradrenaline was markedly lower. These effects were reversed by etanercept. Exposure of iTH+ cells to synovial fluid of RA patients showed similar inhibitory effects. In mixed synovial cells, significant effects of TNF on catecholamine release were observed only in OA. This study shows that TNF inhibits iTH+ synovial cells leading to the decrease of secreted noradrenaline. This might be a reason why discovered newly appearing TH+ cells in the synovium are not able to develop their possible full anti-inflammatory role in arthritis.
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A New Venue of TNF Targeting. Int J Mol Sci 2018; 19:ijms19051442. [PMID: 29751683 PMCID: PMC5983675 DOI: 10.3390/ijms19051442] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Revised: 04/25/2018] [Accepted: 05/03/2018] [Indexed: 12/20/2022] Open
Abstract
The first Food and Drug Administration-(FDA)-approved drugs were small, chemically-manufactured and highly active molecules with possible off-target effects, followed by protein-based medicines such as antibodies. Conventional antibodies bind a specific protein and are becoming increasingly important in the therapeutic landscape. A very prominent class of biologicals are the anti-tumor necrosis factor (TNF) drugs that are applied in several inflammatory diseases that are characterized by dysregulated TNF levels. Marketing of TNF inhibitors revolutionized the treatment of diseases such as Crohn’s disease. However, these inhibitors also have undesired effects, some of them directly associated with the inherent nature of this drug class, whereas others are linked with their mechanism of action, being pan-TNF inhibition. The effects of TNF can diverge at the level of TNF format or receptor, and we discuss the consequences of this in sepsis, autoimmunity and neurodegeneration. Recently, researchers tried to design drugs with reduced side effects. These include molecules with more specificity targeting one specific TNF format or receptor, or that neutralize TNF in specific cells. Alternatively, TNF-directed biologicals without the typical antibody structure are manufactured. Here, we review the complications related to the use of conventional TNF inhibitors, together with the anti-TNF alternatives and the benefits of selective approaches in different diseases.
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Monocytes are essential for the neuroprotective effect of human cord blood cells following middle cerebral artery occlusion in rat. Mol Cell Neurosci 2014; 59:76-84. [PMID: 24472845 DOI: 10.1016/j.mcn.2014.01.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Revised: 01/17/2014] [Accepted: 01/20/2014] [Indexed: 12/17/2022] Open
Abstract
Systemic administration of human umbilical cord blood (HUCB) mononuclear cells (MNC) following middle cerebral artery occlusion (MCAO) in the rat reduces infarct size and, more importantly, restores motor function. The HUCB cell preparation is composed of immature T-cells, B-cells, monocytes and stem cells. In this study we examined whether the beneficial effects of HUCB injection were attributable to one of these cell types. Male Sprague Dawley rats underwent permanent MCAO followed 48 h later by intravenous administration of HUCB MNC preparations depleted of either CD14(+) monocytes, CD133(+) stem cells, CD2(+) T-cells or CD19(+) B cells. Motor function was measured prior to MCAO and 30 days post-stroke. When CD14(+) monocytes were depleted from the HUCB MNC, activity and motor asymmetry were similar to the MCAO only treated animals. Monocyte depletion prevented HUCB cell treatment from reducing infarct size while monocyte enrichment was sufficient to reduce infarct size. Administration of monocyte-depleted HUCB cells did not suppress Iba1 labeling of microglia in the infarcted area relative to treatment with the whole HUCB preparation. These data demonstrate that the HUCB monocytes provide the majority of the efficacy in reducing infarct volume and promoting functional recovery.
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Leal MC, Casabona JC, Puntel M, Pitossi FJ. Interleukin-1β and tumor necrosis factor-α: reliable targets for protective therapies in Parkinson's Disease? Front Cell Neurosci 2013; 7:53. [PMID: 23641196 PMCID: PMC3638129 DOI: 10.3389/fncel.2013.00053] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Accepted: 04/10/2013] [Indexed: 12/31/2022] Open
Abstract
Neuroinflammation has received increased attention as a target for putative neuroprotective therapies in Parkinson’s Disease (PD). Two prototypic pro-inflammatory cytokines interleukin-1β (IL-1) and tumor necrosis factor-α (TNF) have been implicated as main effectors of the functional consequences of neuroinflammation on neurodegeneration in PD models. In this review, we describe that the functional interaction between these cytokines in the brain differs from the periphery (e.g., their expression is not induced by each other) and present data showing predominantly a toxic effect of these cytokines when expressed at high doses and for a sustained period of time in the substantia nigra pars compacta (SN). In addition, we highlight opposite evidence showing protective effects of these two main cytokines when conditions of duration, amount of expression or state of activation of the target or neighboring cells are changed. Furthermore, we discuss these results in the frame of previous disappointing results from anti-TNF-α clinical trials against Multiple Sclerosis, another neurodegenerative disease with a clear neuroinflammatory component. In conclusion, we hypothesize that the available evidence suggests that the duration and dose of IL-1β or TNF-α expression is crucial to predict their functional effect on the SN. Since these parameters are not amenable for measurement in the SN of PD patients, we call for an in-depth analysis to identify downstream mediators that could be common to the toxic (and not the protective) effects of these cytokines in the SN. This strategy could spare the possible neuroprotective effect of these cytokines operative in the patient at the time of treatment, increasing the probability of efficacy in a clinical setting. Alternatively, receptor-specific agonists or antagonists could also provide a way to circumvent undesired effects of general anti-inflammatory or specific anti-IL-1β or TNF-α therapies against PD.
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Affiliation(s)
- María C Leal
- Institute Leloir Fundation - IIBBA-CONICET Buenos Aires, Argentina
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Rehnmark A, Strömberg I. Antioxidant-Enriched Diet Affects Early Microglia Accumulation and Promotes Regeneration of the Striatal Dopamine System after a 6-Hydroxidopamine-Induced Lesion in a Rat. J Exp Neurosci 2012. [DOI: 10.4137/jen.s10424] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Neuroinflammation is found both in the brain of humans suffering from Parkinson's disease and in animal models of disease. It is suggested to be involved in the pathogenesis of the disease. In the present study, in order to study the effects of antioxidants on neuroinflammation, microglial phenotypes were evaluated in rats fed with diets containing bilberries, blueberries, or crowberries at 1 and 4 weeks following striatal injection of 6-hydroxydopamine. The dopamine innervation was visualized using antibodies raised against tyrosine hydroxlase (TH) in the striatum and in the globus pallidus. One week post-lesion, the expression of Iba1-positive cells, a general microglial marker, was significantly increased in the striatum of all animals fed with antioxidant-enriched diets compared to control-diet fed animals, while the diameter of the TH-negative zone was similar in all animals. At four weeks post-lesion, the Iba1-positive microglia was significantly reduced in animals fed with antioxidant-enriched diets. The diameter of the TH-negative zone was significantly reduced in animals fed bilberry and crowberry. The expression and distribution of ED1-positive cells was similar to that of Iba1-positive cells found in the lesioned areas. A cell division marker Ki67 revealed that few microglia were proliferating in crowberry-treated animals. Otherwise dividing cells were associated with blood capillary cells. Although the antioxidant level should be equal in the entire brain, no regeneration was found in globus pallidus, suggesting the mechanism promoting regeneration in the striatum is not effective in the globus pallidus. In conclusion, diets rich in bilberries and crowberries and with high contents of antioxidants stimulate an early phase of accumulation of reactive migroglia that fades at longer time points i.e. promotes regeneration of the striatal dopamine system.
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Affiliation(s)
- Anna Rehnmark
- Integrative Medical Biology, Umeå University, Umeå, Sweden
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Pabon MM, Jernberg JN, Morganti J, Contreras J, Hudson CE, Klein RL, Bickford PC. A spirulina-enhanced diet provides neuroprotection in an α-synuclein model of Parkinson's disease. PLoS One 2012; 7:e45256. [PMID: 23028885 PMCID: PMC3445455 DOI: 10.1371/journal.pone.0045256] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Accepted: 08/16/2012] [Indexed: 11/19/2022] Open
Abstract
Inflammation in the brain plays a major role in neurodegenerative diseases. In particular, microglial cell activation is believed to be associated with the pathogenesis of neurodegenerative diseases, including Parkinson's disease (PD). An increase in microglia activation has been shown in the substantia nigra pars compacta (SNpc) of PD models when there has been a decrease in tyrosine hydroxylase (TH) positive cells. This may be a sign of neurotoxicity due to prolonged activation of microglia in both early and late stages of disease progression. Natural products, such as spirulina, derived from blue green algae, are believed to help reverse this effect due to its anti-inflammatory/anti-oxidant properties. An adeno-associated virus vector (AAV9) for α-synuclein was injected in the substantia nigra of rats to model Parkinson's disease and to study the effects of spirulina on the inflammatory response. One month prior to surgeries, rats were fed either a diet enhanced with spirulina or a control diet. Immunohistochemistry was analyzed with unbiased stereological methods to quantify lesion size and microglial activation. As hypothesized, spirulina was neuroprotective in this α-synuclein model of PD as more TH+ and NeuN+ cells were observed; spirulina concomitantly decreased the numbers of activated microglial cells as determined by MHCII expression. This decrease in microglia activation may have been due, in part, to the effect of spirulina to increase expression of the fractalkine receptor (CX3CR1) on microglia. With this study we hypothesize that α-synuclein neurotoxicity is mediated, at least in part, via an interaction with microglia. We observed a decrease in activated microglia in the rats that received a spirulina- enhanced diet concomitant to neuroprotection. The increase in CX3CR1 in the groups that received spirulina, suggests a potential mechanism of action.
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Affiliation(s)
- Mibel M. Pabon
- Department of Molecular Pharmacology and Physiology, University of South Florida, College of Medicine, Tampa, Florida, United States of America
- Department of Neurosurgery, Center of Excellence for Aging and Brain Repair, University of South Florida, College of Medicine, Tampa, Florida, United States of America
| | - Jennifer N. Jernberg
- Tulane University, Department of Neuroscience, New Orleans, Louisiana, United States of America
| | - Josh Morganti
- Department of Molecular Pharmacology and Physiology, University of South Florida, College of Medicine, Tampa, Florida, United States of America
- Department of Neurosurgery, Center of Excellence for Aging and Brain Repair, University of South Florida, College of Medicine, Tampa, Florida, United States of America
| | - Jessika Contreras
- Department of Neurosurgery, Center of Excellence for Aging and Brain Repair, University of South Florida, College of Medicine, Tampa, Florida, United States of America
| | - Charles E. Hudson
- James A. Haley Veterans Administration Hospital, Tampa, Florida, United States of America
| | - Ronald L. Klein
- Department of Pharmacology, Toxicology and Neuroscience Louisiana State University Health Sciences Center, Shreveport, Louisiana, United States of America
| | - Paula C. Bickford
- Department of Molecular Pharmacology and Physiology, University of South Florida, College of Medicine, Tampa, Florida, United States of America
- Department of Neurosurgery, Center of Excellence for Aging and Brain Repair, University of South Florida, College of Medicine, Tampa, Florida, United States of America
- James A. Haley Veterans Administration Hospital, Tampa, Florida, United States of America
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10
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Park SH, Ozden O, Jiang H, Cha YI, Pennington JD, Aykin-Burns N, Spitz DR, Gius D, Kim HS. Sirt3, mitochondrial ROS, ageing, and carcinogenesis. Int J Mol Sci 2011; 12:6226-39. [PMID: 22016654 PMCID: PMC3189778 DOI: 10.3390/ijms12096226] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Revised: 09/14/2011] [Accepted: 09/20/2011] [Indexed: 02/07/2023] Open
Abstract
One fundamental observation in cancer etiology is that the rate of malignancies in any mammalian population increases exponentially as a function of age, suggesting a mechanistic link between the cellular processes governing longevity and carcinogenesis. In addition, it is well established that aberrations in mitochondrial metabolism, as measured by increased reactive oxygen species (ROS), are observed in both aging and cancer. In this regard, genes that impact upon longevity have recently been characterized in S. cerevisiae and C. elegans, and the human homologs include the Sirtuin family of protein deacetylases. Interestingly, three of the seven sirtuin proteins are localized into the mitochondria suggesting a connection between the mitochondrial sirtuins, the free radical theory of aging, and carcinogenesis. Based on these results it has been hypothesized that Sirt3 functions as a mitochondrial fidelity protein whose function governs both aging and carcinogenesis by modulating ROS metabolism. Sirt3 has also now been identified as a genomically expressed, mitochondrial localized tumor suppressor and this review will outline potential relationships between mitochondrial ROS/superoxide levels, aging, and cell phenotypes permissive for estrogen and progesterone receptor positive breast carcinogenesis.
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Affiliation(s)
- Seong-Hoon Park
- Department of Cancer Biology, Pediatrics, and Radiation Oncology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; E-Mails: (S.-H.P.); (O.O.); (H.J.); (Y.I.C.); (J.D.P.); (D.G.)
| | - Ozkan Ozden
- Department of Cancer Biology, Pediatrics, and Radiation Oncology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; E-Mails: (S.-H.P.); (O.O.); (H.J.); (Y.I.C.); (J.D.P.); (D.G.)
| | - Haiyan Jiang
- Department of Cancer Biology, Pediatrics, and Radiation Oncology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; E-Mails: (S.-H.P.); (O.O.); (H.J.); (Y.I.C.); (J.D.P.); (D.G.)
| | - Yong I. Cha
- Department of Cancer Biology, Pediatrics, and Radiation Oncology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; E-Mails: (S.-H.P.); (O.O.); (H.J.); (Y.I.C.); (J.D.P.); (D.G.)
| | - J. Daniel Pennington
- Department of Cancer Biology, Pediatrics, and Radiation Oncology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; E-Mails: (S.-H.P.); (O.O.); (H.J.); (Y.I.C.); (J.D.P.); (D.G.)
| | - Nukhet Aykin-Burns
- Free Radical and Radiation Biology Program, Department of Radiation Oncology, Holden Comprehensive Cancer Center, The University of Iowa, Iowa City, IA 52242, USA; E-Mails: (N.A.-B.); (D.R.S.)
| | - Douglas R. Spitz
- Free Radical and Radiation Biology Program, Department of Radiation Oncology, Holden Comprehensive Cancer Center, The University of Iowa, Iowa City, IA 52242, USA; E-Mails: (N.A.-B.); (D.R.S.)
| | - David Gius
- Department of Cancer Biology, Pediatrics, and Radiation Oncology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; E-Mails: (S.-H.P.); (O.O.); (H.J.); (Y.I.C.); (J.D.P.); (D.G.)
| | - Hyun-Seok Kim
- Department of Cancer Biology, Pediatrics, and Radiation Oncology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; E-Mails: (S.-H.P.); (O.O.); (H.J.); (Y.I.C.); (J.D.P.); (D.G.)
- Author to whom correspondence should be addressed; E-Mail:
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11
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Pabon MM, Bachstetter AD, Hudson CE, Gemma C, Bickford PC. CX3CL1 reduces neurotoxicity and microglial activation in a rat model of Parkinson's disease. J Neuroinflammation 2011; 8:9. [PMID: 21266082 PMCID: PMC3039584 DOI: 10.1186/1742-2094-8-9] [Citation(s) in RCA: 165] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2010] [Accepted: 01/25/2011] [Indexed: 11/23/2022] Open
Abstract
Background Parkinson's disease is characterized by a progressive loss of dopaminergic neurons in the substantia nigra. The cause of the neurodegeneration is unknown. Neuroinflammation has been clearly shown in Parkinson's disease and may be involved in the progressive nature of the disease. Microglia are capable of producing neuronal damage through the production of bioactive molecules such as cytokines, as well as reactive oxygen species (ROS), and nitric oxide (NO). The inflammatory response in the brain is tightly regulated at multiple levels. One form of immune regulation occurs via neurons. Fractalkine (CX3CL1), produced by neurons, suppresses the activation of microglia. CX3CL1 is constitutively expressed. It is not known if addition of exogenous CX3CL1 beyond otherwise physiologically normal levels could decrease microglia activation and thereby minimize the secondary neurodegeration following a neurotoxic insult. Methods The intrastriatal 6-hydroxydopamine (6-OHDA) rat model of Parkinson disease, was used to test the hypothesis that exogenous CX3CL1 could be neuroprotective. Treatment with recombinant CX3CL1 was delivered to the striatum by an osmotic minipump for 28 days beginning 7 days after the initial insult. Unbiased stereological methods were used to quantify the lesion size in the striatum, the amount of neuronal loss in the substantia nigra, and the amount of microglia activation. Results As hypothesized, CX3CL1 was able to suppress this microglia activation. The reduced microglia activation was found to be neuroprotective as the CX3CL1 treated rats had a smaller lesion volume in the striatum and importantly significantly fewer neurons were lost in the CX3CL1 treated rats. Conclusion These findings demonstrated that CX3CL1 plays a neuroprotective role in 6-OHDA-induced dopaminergic lesion and it might be an effective therapeutic target for many neurodegenerative diseases, including Parkinson disease and Alzheimer disease, where inflammation plays an important role.
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Affiliation(s)
- Mibel M Pabon
- Department of Molecular Pharmacology and Physiology, University of South Florida, College of Medicine, Tampa, FL 33612, USA
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12
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Neuroprotective and neurodegenerative effects of the chronic expression of tumor necrosis factor α in the nigrostriatal dopaminergic circuit of adult mice. Exp Neurol 2010; 227:237-51. [PMID: 21093436 DOI: 10.1016/j.expneurol.2010.11.010] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2009] [Revised: 09/20/2010] [Accepted: 11/09/2010] [Indexed: 12/19/2022]
Abstract
Tumor necrosis factor (TNF)-α, a pro-inflammatory cytokine, has been implicated in both neuronal death and survival in Parkinson's disease (PD). The substantia nigra (SN), a CNS region affected in PD, is particularly susceptible to inflammatory insults and possesses the highest density of microglial cells, but the effects of inflammation and in particular TNF-α on neuronal survival in this region remains controversial. Using adenoviral vectors, the CRE/loxP system and hypomorphic mice, we achieved chronic expression of two levels of TNF-α in the SN of adult mice. Chronic low expression of TNF-α levels reduced the nigrostriatal neurodegeneration mediated by intrastriatal 6-hydroxydopamine administration. Protective effects of low TNF-α level could be mediated by TNF-R1, GDNF, and IGF-1 in the SN and SOD activity in the striatum (ST). On the contrary, chronic expression of high levels of TNF-α induced progressive neuronal loss (63% at 20 days and 75% at 100 days). This effect was accompanied by gliosis and an inflammatory infiltrate composed almost exclusively by monocytes/macrophages. The finding that chronic high TNF-α had a slow and progressive neurodegenerative effect in the SN provides an animal model of PD mediated by the chronic expression of a single cytokine. In addition, it supports the view that cytokines are not detrimental or beneficial by themselves, i.e., their level and time of expression among other factors can determine its final effect on CNS damage or protection. These data support the view that new anti-parkinsonian treatments based on anti-inflammatory therapies should consider these dual effects of cytokines on their design.
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Boger HA, Middaugh LD, Zaman V, Hoffer B, Granholm AC. Differential effects of the dopamine neurotoxin MPTP in animals with a partial deletion of the GDNF receptor, GFR alpha1, gene. Brain Res 2008; 1241:18-28. [PMID: 18822276 DOI: 10.1016/j.brainres.2008.09.011] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2008] [Revised: 08/30/2008] [Accepted: 09/08/2008] [Indexed: 11/19/2022]
Abstract
Glial cell line-derived neurotrophic factor (GDNF), a member of the transforming growth factor beta (TGFbeta) superfamily, is a potent neurotrophic protein promoting the survival and maintenance of dopaminergic (DA) neurons in the substantia nigra during development and adulthood. DA neurons that project to the striatum in the nigrostriatal pathway express GDNF receptors, GFR alpha1. The purpose of this study was to determine whether these neurons are especially sensitive to neurotoxic insults. Therefore, we examined effects of the dopaminergic toxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) on locomotion and DA neurons in 26-month-old male GFR alpha1 heterozygous (GFR alpha1(+/-)) mice compared to aged-matched wild-type (WT) littermates. MPTP gave rise to increased locomotion, regardless of genotype, while GFR alpha1(+/-) mice treated with saline exhibited lower spontaneous locomotion, compared to WT mice. Moreover, GFR alpha1(+/-) saline mice had fewer TH-positive neurons, greater expression of inflammatory markers (CD45 immunostaining and phosphorylated p38 MAPK) in the nigra, and reduced striatal TH staining. MPTP exacerbated these effects, with the lowest density of striatal TH and highest density of nigral CD45 and phospho-p38 MAPK immunoreactivity observed in GFR alpha1(+/-) mice. The findings point to increased sensitivity of the DAergic system with age and neurotoxic exposure as a result of a genetic reduction of GFR alpha1.
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Affiliation(s)
- Heather A Boger
- Department of Neurosciences, Center on Aging, Medical University of South Carolina, Charleston, SC 29425, USA.
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Marschinke F, Strömberg I. Dual effects of TNFalpha on nerve fiber formation from ventral mesencephalic organotypic tissue cultures. Brain Res 2008; 1215:30-9. [PMID: 18482714 DOI: 10.1016/j.brainres.2008.03.070] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2007] [Revised: 02/12/2008] [Accepted: 03/26/2008] [Indexed: 01/03/2023]
Abstract
Tumor necrosis factor alpha (TNFalpha) is toxic to dopamine neurons and increased levels of TNFalpha are observed in Parkinson's disease. Dopamine nerve fiber outgrowth in organotypic cultures of fetal ventral mesencephalon occurs in two waves. The early appearing nerve fibers are formed in the absence of astroglia, while migrating astrocytes guide the late appearing dopamine nerve fibers. TNFalpha (40 ng/ml) was added to the medium of organotypic ventral mesencephalic tissue cultures between days 4-7 and 11-14. The cultures were evaluated at days 7 or 19 to study the effects of TNFalpha on both types of nerve fiber formation. Tyrosine hydroxylase (TH)-immunohistochemistry demonstrated that the number of cultures showing non-glial-guided TH-positive outgrowth was reduced compared to controls, when TNFalpha was added at day 4. By contrast, the glial-guided TH-positive nerve fiber outgrowth and the astrocytic migration reached significantly longer distances by early TNFalpha treatment. Ki67-immunohistochemistry revealed that TNFalpha did not affect proliferation of astrocytes. Treatment with TNFalpha and antibodies against TNFalpha receptor 1 between days 4 and 7 revealed that the non-glial-guided TH-positive outgrowth reappeared. TNFalpha treatment between days 11 and 14 triggered neither the TH-positive glial-guided outgrowth, nor promoted the astrocytic migration to reach longer distances. The number of microglia was significantly increased after the late but not early TNFalpha treatment. In conclusion, TNFalpha is toxic for the non-glial dopaminergic nerve fiber outgrowth but stimulates the glial-guided outgrowth and the migration of astrocytes at an early time point. TNFalpha increased the number of microglia in VM tissue cultures after late but not after early treatment.
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Affiliation(s)
- Franziska Marschinke
- Department of Integrative Medical Biology, Umeå University, S-901 87 Umeå, Sweden
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