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De Luca C, Virtuoso A, Korai SA, Cirillo R, Gargano F, Papa M, Cirillo G. Altered Spinal Homeostasis and Maladaptive Plasticity in GFAP Null Mice Following Peripheral Nerve Injury. Cells 2022; 11:cells11071224. [PMID: 35406788 PMCID: PMC8997460 DOI: 10.3390/cells11071224] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 03/25/2022] [Accepted: 03/31/2022] [Indexed: 12/14/2022] Open
Abstract
The maladaptive response of the central nervous system (CNS) following nerve injury is primarily linked to the activation of glial cells (reactive gliosis) that produce an inflammatory reaction and a wide cellular morpho-structural and functional/metabolic remodeling. Glial acidic fibrillary protein (GFAP), a major protein constituent of astrocyte intermediate filaments (IFs), is the hallmark of the reactive astrocytes, has pleiotropic functions and is significantly upregulated in the spinal cord after nerve injury. Here, we investigated the specific role of GFAP in glial reaction and maladaptive spinal cord plasticity following sciatic nerve spared nerve injury (SNI) in GFAP KO and wild-type (WT) animals. We evaluated the neuropathic behavior (thermal hyperalgesia, allodynia) and the expression of glial (vimentin, Iba1) and glutamate/GABA system markers (GLAST, GLT1, EAAC1, vGLUT, vGAT, GAD) in lumbar spinal cord sections of KO/WT animals. SNI induced neuropathic behavior in both GFAP KO and WT mice, paralleled by intense microglial reaction (Iba1 expression more pronounced in KO mice), reactive astrocytosis (vimentin increase) and expression remodeling of glial/neuronal glutamate/GABA transporters. In conclusion, it is conceivable that the lack of GFAP could be detrimental to the CNS as it lacks a critical sensor for neuroinflammation and morpho-functional–metabolic rewiring after nerve injury. Understanding the maladaptive morpho-functional changes of glial cells could represent the first step for a new glial-based targeted approach for mechanisms of disease in the CNS.
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Affiliation(s)
- Ciro De Luca
- Neural Network Morphology & Systems Biology Lab, Division of Human Anatomy, Department of Mental and Physical Health and Preventive Medicine, University of Campania “Luigi Vanvitelli”, 80138 Naples, Italy; (C.D.L.); (A.V.); (S.A.K.); (R.C.); (M.P.)
| | - Assunta Virtuoso
- Neural Network Morphology & Systems Biology Lab, Division of Human Anatomy, Department of Mental and Physical Health and Preventive Medicine, University of Campania “Luigi Vanvitelli”, 80138 Naples, Italy; (C.D.L.); (A.V.); (S.A.K.); (R.C.); (M.P.)
| | - Sohaib Ali Korai
- Neural Network Morphology & Systems Biology Lab, Division of Human Anatomy, Department of Mental and Physical Health and Preventive Medicine, University of Campania “Luigi Vanvitelli”, 80138 Naples, Italy; (C.D.L.); (A.V.); (S.A.K.); (R.C.); (M.P.)
| | - Raffaella Cirillo
- Neural Network Morphology & Systems Biology Lab, Division of Human Anatomy, Department of Mental and Physical Health and Preventive Medicine, University of Campania “Luigi Vanvitelli”, 80138 Naples, Italy; (C.D.L.); (A.V.); (S.A.K.); (R.C.); (M.P.)
| | - Francesca Gargano
- Unit of Anesthesia, Intensive Care and Pain Management, Department of Medicine, Campus Bio-Medico University of Rome, 00128 Rome, Italy;
| | - Michele Papa
- Neural Network Morphology & Systems Biology Lab, Division of Human Anatomy, Department of Mental and Physical Health and Preventive Medicine, University of Campania “Luigi Vanvitelli”, 80138 Naples, Italy; (C.D.L.); (A.V.); (S.A.K.); (R.C.); (M.P.)
- SYSBIO Centre of Systems Biology ISBE.ITALY, University of Milano-Bicocca, 20126 Milano, Italy
| | - Giovanni Cirillo
- Neural Network Morphology & Systems Biology Lab, Division of Human Anatomy, Department of Mental and Physical Health and Preventive Medicine, University of Campania “Luigi Vanvitelli”, 80138 Naples, Italy; (C.D.L.); (A.V.); (S.A.K.); (R.C.); (M.P.)
- Correspondence: ; Tel.: +39-081-5666008
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Causal biological network models for reactive astrogliosis: a systems approach to neuroinflammation. Sci Rep 2022; 12:4205. [PMID: 35273209 PMCID: PMC8913664 DOI: 10.1038/s41598-022-07651-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 02/15/2022] [Indexed: 11/22/2022] Open
Abstract
Astrocytes play a central role in the neuroimmune response by responding to CNS pathologies with diverse molecular and morphological changes during the process of reactive astrogliosis. Here, we used a computational biological network model and mathematical algorithms that allow the interpretation of high-throughput transcriptomic datasets in the context of known biology to study reactive astrogliosis. We gathered available mechanistic information from the literature into a comprehensive causal biological network (CBN) model of astrocyte reactivity. The CBN model was built in the Biological Expression Language, which is both human-readable and computable. We characterized the CBN with a network analysis of highly connected nodes and demonstrated that the CBN captures relevant astrocyte biology. Subsequently, we used the CBN and transcriptomic data to identify key molecular pathways driving the astrocyte phenotype in four CNS pathologies: samples from mouse models of lipopolysaccharide-induced endotoxemia, Alzheimer’s disease, and amyotrophic lateral sclerosis; and samples from multiple sclerosis patients. The astrocyte CBN provides a new tool to identify causal mechanisms and quantify astrogliosis based on transcriptomic data.
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3
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Wang Y, Niu Y, Lin F, Su P, Chen L, Liu D, Sun Y. X-ray Irradiation Improves Neurological Function Recovery of Injured Spinal Cord by Inhibiting Inflammation and Glial Scar Formation. J Mol Neurosci 2022; 72:1008-1017. [DOI: 10.1007/s12031-022-01975-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 01/17/2022] [Indexed: 10/19/2022]
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4
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Hong J, Dragas R, Khazaei M, Ahuja CS, Fehlings MG. Hepatocyte Growth Factor-Preconditioned Neural Progenitor Cells Attenuate Astrocyte Reactivity and Promote Neurite Outgrowth. Front Cell Neurosci 2021; 15:741681. [PMID: 34955750 PMCID: PMC8695970 DOI: 10.3389/fncel.2021.741681] [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: 07/15/2021] [Accepted: 11/09/2021] [Indexed: 11/13/2022] Open
Abstract
The astroglial scar is a defining hallmark of secondary pathology following central nervous system (CNS) injury that, despite its role in limiting tissue damage, presents a significant barrier to neuroregeneration. Neural progenitor cell (NPC) therapies for tissue repair and regeneration have demonstrated favorable outcomes, the effects of which are ascribed not only to direct cell replacement but trophic support. Cytokines and growth factors secreted by NPCs aid in modifying the inhibitory and cytotoxic post-injury microenvironment. In an effort to harness and enhance the reparative potential of NPC secretome, we utilized the multifunctional and pro-regenerative cytokine, hepatocyte growth factor (HGF), as a cellular preconditioning agent. We first demonstrated the capacity of HGF to promote NPC survival in the presence of oxidative stress. We then assessed the capacity of this modified conditioned media (CM) to attenuate astrocyte reactivity and promote neurite outgrowth in vitro. HGF pre-conditioned NPCs demonstrated significantly increased levels of tissue inhibitor of metalloproteinases-1 and reduced vascular endothelial growth factor compared to untreated NPCs. In reactive astrocytes, HGF-enhanced NPC-CM effectively reduced glial fibrillary acidic protein (GFAP) expression and chondroitin sulfate proteoglycan deposition to a greater extent than either treatment alone, and enhanced neurite outgrowth of co-cultured neurons. in vivo, this combinatorial treatment strategy might enable tactical modification of the post-injury inhibitory astroglial environment to one that is more conducive to regeneration and functional recovery. These findings have important translational implications for the optimization of current cell-based therapies for CNS injury.
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Affiliation(s)
- James Hong
- Department of Genetics and Development, Krembil Research Institute, University Health Network, Toronto, ON, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Rachel Dragas
- Department of Genetics and Development, Krembil Research Institute, University Health Network, Toronto, ON, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Mohammad Khazaei
- Department of Genetics and Development, Krembil Research Institute, University Health Network, Toronto, ON, Canada
| | - Christopher S Ahuja
- Department of Genetics and Development, Krembil Research Institute, University Health Network, Toronto, ON, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Michael G Fehlings
- Department of Genetics and Development, Krembil Research Institute, University Health Network, Toronto, ON, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, Canada.,Spinal Program, University Health Network, Toronto Western Hospital, Toronto, ON, Canada
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5
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Telegin GB, Minakov AN, Chernov AS, Kazakov VA, Kalabina EA, Manskikh VN, Asyutin DS, Belogurov AA, Gabibov AG, Konovalov NA, Spallone A. A New Precision Minimally Invasive Method of Glial Scar Simulation in the Rat Spinal Cord Using Cryoapplication. Front Surg 2021; 8:607551. [PMID: 34336912 PMCID: PMC8320592 DOI: 10.3389/fsurg.2021.607551] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 06/17/2021] [Indexed: 12/25/2022] Open
Abstract
According to the World Health Organization, every year worldwide up to 500,000 people suffer a spinal cord injury (SCI). Various animal biomodels are essential for searching for novel protocols and therapeutic approaches for SCI treatment. We have developed an original model of post-traumatic spinal cord glial scarring in rats through cryoapplication. With this method the low-temperature liquid nitrogen is used for the cryodestruction of the spinal cord tissue. Forty-five Sprague Dawley (SD) non-linear male rats of the Specific-pathogen-free (SPF) category were included in this experimental study. A Th13 unilateral hemilaminectomy was performed with dental burr using an operating microscope. A specifically designed cryogenic probe was applied to the spinal cord for one minute through the created bone defect. The animals were euthanized at different time points ranging from 1 to 60 days after cold-induced injury. Their Th12-L1 vertebrae with the injured spinal cord region were removed "en bloc" for histological examination. Our data demonstrate that cryoapplication producing a topical cooling around-20°C, caused a highly standardized transmural lesion of the spinal cord in the dorsoventral direction. The lesion had an "hour-glass" shape on histological sections. During the entire study period (days 1-60 of the post-trauma period), the necrotic processes and the development of the glial scar (lesion evolution) were contained in the surgically approached vertebral space (Th13). Unlike other known experimental methods of SCI simulation (compression, contusion, etc.), the proposed technique is characterized by minimal invasiveness, high precision, and reproducibility. Also, histological findings, lesion size, and postoperative clinical course varied only slightly between different animals. An original design of the cryoprobe used in the study played a primary role in the achieving of these results. The spinal cord lesion's detailed functional morphology is described at different time points (1-60 days) after the produced cryoinjury. Also, changes in the number of macrophages at distinct time points, neoangiogenesis and the formation of the glial scar's fibrous component, including morphodynamic characteristics of its evolution, are analyzed. The proposed method of cryoapplication for inducing reproducible glial scars could facilitate a better understanding of the self-recovery processes in the damaged spinal cord. It would be evidently helpful for finding innovative approaches to the SCI treatment.
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Affiliation(s)
- Georgii B. Telegin
- Branch of Shemyakin and Ovchinnikov, Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Alexey N. Minakov
- Branch of Shemyakin and Ovchinnikov, Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Aleksandr S. Chernov
- Branch of Shemyakin and Ovchinnikov, Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Vitaly A. Kazakov
- Branch of Shemyakin and Ovchinnikov, Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Elena A. Kalabina
- Branch of Shemyakin and Ovchinnikov, Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Vasily N. Manskikh
- A.N. Belozersky Institute of Physico-Chemical Biology, M.V. Lomonosov Moscow State University, Moscow, Russia
| | - Dmitry S. Asyutin
- Department of Spinal Neurosurgery, N.N. Burdenko National Scientific and Practical Center for Neurosurgery, RF Health Ministry, Moscow, Russia
| | - Alexey A. Belogurov
- Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Alexander G. Gabibov
- Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Nikolay A. Konovalov
- Department of Spinal Neurosurgery, N.N. Burdenko National Scientific and Practical Center for Neurosurgery, RF Health Ministry, Moscow, Russia
| | - Aldo Spallone
- Department of Clinical Neurosciences, NCL-Neuromed Institute of Neurosciences, Rome, Italy
- Department of Nervous Diseases, RUDN University, Moscow, Russia
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6
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Cohrs G, Drucks B, Sürie JP, Vokuhl C, Synowitz M, Held-Feindt J, Knerlich-Lukoschus F. Expression profiles of pro-inflammatory and pro-apoptotic mediators in secondary tethered cord syndrome after myelomeningocele repair surgery. Childs Nerv Syst 2019; 35:315-328. [PMID: 30280214 DOI: 10.1007/s00381-018-3984-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 09/21/2018] [Indexed: 11/27/2022]
Abstract
PURPOSE The literature on histopathological and molecular changes that might underlie secondary tethered cord syndrome (TCS) after myelomeningocele (MMC) repair surgeries remains sparse. To address this problem, we analyzed specimens, which were obtained during untethering surgeries of patients who had a history of MMC repair surgery after birth. METHODS Specimens of 12 patients were analyzed in this study. Clinical characteristics were obtained retrospectively including pre-operative neurological and bowel/bladder-function, contractures and spasticity of lower extremities, leg and back pain, syringomyelia, and conus position on spinal MRI. Cellular marker expression profiles were established. Further, immunoreactivities (IR) of IL-1ß/IL-1R1, TNF-α/TNF-R1, and HIF-1α/-2α were analyzed qualitatively and semi-quantitatively by densitometry. Co-labeling with cellular markers was determined by multi-fluorescence-labeling. Cytokines were further analyzed on mRNA level. Immunostaining for cleaved PARP and TUNEL was performed to detect apoptotic cells. RESULTS Astrocytosis, appearance of monocytes, activated microglia, and apoptotic cells in TCS specimens were one substantial finding of these studies. Besides neurons, these cells co-stained with IL-1ß and TNF-α and their receptors, which were found on significantly elevated IR-level and partially mRNA-level in TCS specimens. Staining for HIF-1α/-2α confirmed induction of hypoxia-related factors in TCS specimens that were co-labeled with IL-1ß. Further, hints for apoptotic cell death became evident by TUNEL and PARP-positive cells in TCS neuroepithelia. CONCLUSIONS Our studies identified pro-inflammatory and pro-apoptotic mediators that, besides mechanical damaging and along with hypoxia, might promote TCS development. Besides optimizing surgical techniques, these factors should also be taken into account when searching for further options to improve TCS treatment.
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Affiliation(s)
- Gesa Cohrs
- Department of Neurosurgery, University Hospital of Schleswig-Holstein Campus Kiel, Arnold-Heller-Str. 3, House 41, 24105, Kiel, Germany
| | - Bea Drucks
- Department of Neurosurgery, University Hospital of Schleswig-Holstein Campus Kiel, Arnold-Heller-Str. 3, House 41, 24105, Kiel, Germany
| | - Jan-Philip Sürie
- Department of Neurosurgery, University Hospital of Schleswig-Holstein Campus Kiel, Arnold-Heller-Str. 3, House 41, 24105, Kiel, Germany
| | - Christian Vokuhl
- Department of Pathology, University Hospital of Schleswig-Holstein Campus Kiel, Arnold-Heller-Str. 3, House 14, 24105, Kiel, Germany
| | - Michael Synowitz
- Department of Neurosurgery, University Hospital of Schleswig-Holstein Campus Kiel, Arnold-Heller-Str. 3, House 41, 24105, Kiel, Germany
| | - Janka Held-Feindt
- Department of Neurosurgery, University Hospital of Schleswig-Holstein Campus Kiel, Arnold-Heller-Str. 3, House 41, 24105, Kiel, Germany
| | - Friederike Knerlich-Lukoschus
- Department of Neurosurgery, University Hospital of Schleswig-Holstein Campus Kiel, Arnold-Heller-Str. 3, House 41, 24105, Kiel, Germany.
- Deparment of Pediatric Neurosurgery, Asklepios klinik Sankt Augstin GmbH, Arnold-Janssen-Str. 29, 53757, Sankt Augustin, Germany.
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7
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Joe EH, Choi DJ, An J, Eun JH, Jou I, Park S. Astrocytes, Microglia, and Parkinson's Disease. Exp Neurobiol 2018; 27:77-87. [PMID: 29731673 PMCID: PMC5934545 DOI: 10.5607/en.2018.27.2.77] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 04/14/2018] [Accepted: 04/16/2018] [Indexed: 12/12/2022] Open
Abstract
Astrocytes and microglia support well-being and well-function of the brain through diverse functions in both intact and injured brain. For example, astrocytes maintain homeostasis of microenvironment of the brain through up-taking ions and neurotransmitters, and provide growth factors and metabolites for neurons, etc. Microglia keep surveying surroundings, and remove abnormal synapses or respond to injury by isolating injury sites and expressing inflammatory cytokines. Therefore, their loss and/or functional alteration may be directly linked to brain diseases. Since Parkinson's disease (PD)-related genes are expressed in astrocytes and microglia, mutations of these genes may alter the functions of these cells, thereby contributing to disease onset and progression. Here, we review the roles of astrocytes and microglia in intact and injured brain, and discuss how PD genes regulate their functions.
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Affiliation(s)
- Eun-Hye Joe
- Department of Pharmacology, Ajou University School of Medicine, Suwon 16944, Korea.,Department of Biomedical Sciences, Neuroscience Graduate Program, Ajou University School of Medicine, Suwon 16944, Korea.,Department of Brain Science, Ajou University School of Medicine, Suwon 16944, Korea.,Chronic Inflammatory Disease Research Center, Ajou University School of Medicine, Suwon 16944, Korea
| | - Dong-Joo Choi
- Department of Pharmacology, Ajou University School of Medicine, Suwon 16944, Korea.,Chronic Inflammatory Disease Research Center, Ajou University School of Medicine, Suwon 16944, Korea
| | - Jiawei An
- Department of Biomedical Sciences, Neuroscience Graduate Program, Ajou University School of Medicine, Suwon 16944, Korea
| | - Jin-Hwa Eun
- Department of Biomedical Sciences, Neuroscience Graduate Program, Ajou University School of Medicine, Suwon 16944, Korea
| | - Ilo Jou
- Department of Pharmacology, Ajou University School of Medicine, Suwon 16944, Korea.,Department of Biomedical Sciences, Neuroscience Graduate Program, Ajou University School of Medicine, Suwon 16944, Korea.,Chronic Inflammatory Disease Research Center, Ajou University School of Medicine, Suwon 16944, Korea
| | - Sangmyun Park
- Department of Pharmacology, Ajou University School of Medicine, Suwon 16944, Korea.,Department of Biomedical Sciences, Neuroscience Graduate Program, Ajou University School of Medicine, Suwon 16944, Korea.,Chronic Inflammatory Disease Research Center, Ajou University School of Medicine, Suwon 16944, Korea
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8
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de Menezes MF, Nicola F, Vital da Silva IR, Vizuete A, Elsner VR, Xavier LL, Gonçalves CAS, Netto CA, Mestriner RG. Glial fibrillary acidic protein levels are associated with global histone H4 acetylation after spinal cord injury in rats. Neural Regen Res 2018; 13:1945-1952. [PMID: 30233068 PMCID: PMC6183034 DOI: 10.4103/1673-5374.239443] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Emerging evidence has suggested global histone H4 acetylation status plays an important role in neural plasticity. For instance, the imbalance of this epigenetic marker has been hypothesized as a key factor for the development and progression of several neurological diseases. Likewise, astrocytic reactivity - a well-known process that markedly influences the tissue remodeling after a central nervous system injury - is crucial for tissue remodeling after spinal cord injury (SCI). However, the linkage between the above-mentioned mechanisms after SCI remains poorly understood. We sought to investigate the relation between both glial fibrillary acidic protein (GFAP) and S100 calcium-binding protein B (S100B) (astrocytic reactivity classical markers) and global histone H4 acetylation levels. Sixty-one male Wistar rats (aged ~3 months) were divided into the following groups: sham; 6 hours post-SCI; 24 hours post-SCI; 48 hours post-SCI; 72 hours post-SCI; and 7 days post-SCI. The results suggested that GFAP, but not S100B was associated with global histone H4 acetylation levels. Moreover, global histone H4 acetylation levels exhibited a complex pattern after SCI, encompassing at least three clearly defined phases ( first phase: no changes in the 6, 24 and 48 hours post-SCI groups; second phase: increased levels in the 72 hours post-SCI group; and a third phase: return to levels similar to control in the 7 days post-SCI group). Overall, these findings suggest global H4 acetylation levels exhibit distinct patterns of expression during the first week post-SCI, which may be associated with GFAP levels in the perilesional tissue. Current data encourage studies using H4 acetylation as a possible biomarker for tissue remodeling after spinal cord injury.
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Affiliation(s)
- Mayara Ferraz de Menezes
- Neurorehabilitation and Neural Repair Research Group; Graduate Program in Cellular and Molecular Biology, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Fabrício Nicola
- Department of Biochemistry, Basic Science Institute, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Ivy Reichert Vital da Silva
- Graduate Program in Biosciences and Rehabilitation, Centro Universitário Metodista IPA, Porto Alegre, RS, Brazil
| | - Adriana Vizuete
- Department of Biochemistry, Basic Science Institute, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Viviane Rostirola Elsner
- Graduate Program in Biosciences and Rehabilitation, Centro Universitário Metodista IPA, Porto Alegre, RS, Brazil
| | - Léder Leal Xavier
- Neurorehabilitation and Neural Repair Research Group; Graduate Program in Cellular and Molecular Biology, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | | | - Carlos Alexandre Netto
- Department of Biochemistry, Basic Science Institute, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Régis Gemerasca Mestriner
- Neurorehabilitation and Neural Repair Research Group; Graduate Program in Cellular and Molecular Biology, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil
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Toutounchian JJ, McCarty JH. Selective expression of eGFP in mouse perivascular astrocytes by modification of the Mlc1 gene using T2A-based ribosome skipping. Genesis 2017; 55. [PMID: 28929580 DOI: 10.1002/dvg.23071] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 09/12/2017] [Accepted: 09/17/2017] [Indexed: 11/12/2022]
Abstract
Perivascular astrocyte end feet closely juxtapose cerebral blood vessels to regulate important developmental and physiological processes including endothelial cell proliferation and sprouting as well as the formation of the blood-brain barrier (BBB). The mechanisms underlying these events remain largely unknown due to a lack of experimental models for identifying perivascular astrocytes and distinguishing these cell types from other astroglial populations. Megalencephalic leukoencephalopathy with subcortical cysts 1 (Mlc1) is a transmembrane protein that is expressed in perivascular astrocyte end feet where it controls BBB development and homeostasis. On the basis of this knowledge, we used T2A peptide-skipping strategies to engineer a knock-in mouse model in which the endogenous Mlc1 gene drives expression of enhanced green fluorescent protein (eGFP), without impacting expression of Mlc1 protein. Analysis of fetal, neonatal and adult Mlc1-eGFP knock-in mice revealed a dynamic spatiotemporal expression pattern of eGFP in glial cells, including nestin-expressing neuroepithelial cells during development and glial fibrillary acidic protein (GFAP)-expressing perivascular astrocytes in the postnatal brain. EGFP was not expressed in neurons, microglia, oligodendroglia, or cerebral vascular cells. Analysis of angiogenesis in the neonatal retina also revealed enriched Mlc1-driven eGFP expression in perivascular astrocytes that contact sprouting blood vessels and regulate blood-retinal barrier permeability. A cortical injury model revealed that Mlc1-eGFP expression is progressively induced in reactive astrocytes that form a glial scar. Hence, Mlc1-eGFP knock-in mice are a new and powerful tool to identify perivascular astrocytes in the brain and retina and characterize how these cell types regulate cerebral blood vessel functions in health and disease.
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Affiliation(s)
- Jordan J Toutounchian
- Department of Neurosurgery, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, 77030
| | - Joseph H McCarty
- Department of Neurosurgery, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, 77030
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10
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Salehi A, Zhang JH, Obenaus A. Response of the cerebral vasculature following traumatic brain injury. J Cereb Blood Flow Metab 2017; 37:2320-2339. [PMID: 28378621 PMCID: PMC5531360 DOI: 10.1177/0271678x17701460] [Citation(s) in RCA: 186] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The critical role of the vasculature and its repair in neurological disease states is beginning to emerge particularly for stroke, dementia, epilepsy, Parkinson's disease, tumors and others. However, little attention has been focused on how the cerebral vasculature responds following traumatic brain injury (TBI). TBI often results in significant injury to the vasculature in the brain with subsequent cerebral hypoperfusion, ischemia, hypoxia, hemorrhage, blood-brain barrier disruption and edema. The sequalae that follow TBI result in neurological dysfunction across a host of physiological and psychological domains. Given the importance of restoring vascular function after injury, emerging research has focused on understanding the vascular response after TBI and the key cellular and molecular components of vascular repair. A more complete understanding of vascular repair mechanisms are needed and could lead to development of new vasculogenic therapies, not only for TBI but potentially vascular-related brain injuries. In this review, we delineate the vascular effects of TBI, its temporal response to injury and putative biomarkers for arterial and venous repair in TBI. We highlight several molecular pathways that may play a significant role in vascular repair after brain injury.
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Affiliation(s)
- Arjang Salehi
- 1 Cell, Molecular and Developmental Biology Program, University of California, Riverside, CA, USA.,2 Department of Pediatrics, Loma Linda University, Loma Linda, CA, USA
| | - John H Zhang
- 3 Department of Physiology and Pharmacology Loma Linda University School of Medicine, CA, USA.,4 Department of Anesthesiology Loma Linda University School of Medicine, CA, USA.,5 Department of Neurosurgery, Loma Linda University School of Medicine, Loma Linda, CA, USA
| | - Andre Obenaus
- 1 Cell, Molecular and Developmental Biology Program, University of California, Riverside, CA, USA.,2 Department of Pediatrics, Loma Linda University, Loma Linda, CA, USA.,6 Department of Pediatrics, University of California, Irvine, Irvine, CA, USA
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11
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Corrigan F, Mander KA, Leonard AV, Vink R. Neurogenic inflammation after traumatic brain injury and its potentiation of classical inflammation. J Neuroinflammation 2016; 13:264. [PMID: 27724914 PMCID: PMC5057243 DOI: 10.1186/s12974-016-0738-9] [Citation(s) in RCA: 207] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 09/28/2016] [Indexed: 01/05/2023] Open
Abstract
Background The neuroinflammatory response following traumatic brain injury (TBI) is known to be a key secondary injury factor that can drive ongoing neuronal injury. Despite this, treatments that have targeted aspects of the inflammatory pathway have not shown significant efficacy in clinical trials. Main body We suggest that this may be because classical inflammation only represents part of the story, with activation of neurogenic inflammation potentially one of the key initiating inflammatory events following TBI. Indeed, evidence suggests that the transient receptor potential cation channels (TRP channels), TRPV1 and TRPA1, are polymodal receptors that are activated by a variety of stimuli associated with TBI, including mechanical shear stress, leading to the release of neuropeptides such as substance P (SP). SP augments many aspects of the classical inflammatory response via activation of microglia and astrocytes, degranulation of mast cells, and promoting leukocyte migration. Furthermore, SP may initiate the earliest changes seen in blood-brain barrier (BBB) permeability, namely the increased transcellular transport of plasma proteins via activation of caveolae. This is in line with reports that alterations in transcellular transport are seen first following TBI, prior to decreases in expression of tight-junction proteins such as claudin-5 and occludin. Indeed, the receptor for SP, the tachykinin NK1 receptor, is found in caveolae and its activation following TBI may allow influx of albumin and other plasma proteins which directly augment the inflammatory response by activating astrocytes and microglia. Conclusions As such, the neurogenic inflammatory response can exacerbate classical inflammation via a positive feedback loop, with classical inflammatory mediators such as bradykinin and prostaglandins then further stimulating TRP receptors. Accordingly, complete inhibition of neuroinflammation following TBI may require the inhibition of both classical and neurogenic inflammatory pathways.
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Affiliation(s)
- Frances Corrigan
- Adelaide Centre for Neuroscience Research, School of Medicine, The University of Adelaide, Adelaide, South Australia, Australia.
| | - Kimberley A Mander
- Adelaide Centre for Neuroscience Research, School of Medicine, The University of Adelaide, Adelaide, South Australia, Australia
| | - Anna V Leonard
- Adelaide Centre for Neuroscience Research, School of Medicine, The University of Adelaide, Adelaide, South Australia, Australia
| | - Robert Vink
- Sansom Institute for Health Research, The University of South Australia, Adelaide, South Australia, Australia
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Shao WY, Liu X, Gu XL, Ying X, Wu N, Xu HW, Wang Y. Promotion of axon regeneration and inhibition of astrocyte activation by alpha A-crystallin on crushed optic nerve. Int J Ophthalmol 2016; 9:955-66. [PMID: 27500100 DOI: 10.18240/ijo.2016.07.04] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2016] [Accepted: 05/25/2016] [Indexed: 11/23/2022] Open
Abstract
AIM To explore the effects of αA-crystallin in astrocyte gliosis after optic nerve crush (ONC) and the mechanism of α-crystallin in neuroprotection and axon regeneration. METHODS ONC was established on the Sprague-Dawley rat model and αA-crystallin (10(-4) g/L, 4 µL) was intravitreously injected into the rat model. Flash-visual evoked potential (F-VEP) was examined 14d after ONC, and the glial fibrillary acidic protein (GFAP) levels in the retina and crush site were analyzed 1, 3, 5, 7 and 14d after ONC by immunohistochemistry (IHC) and Western blot respectively. The levels of beta Tubulin (TUJ1), growth-associated membrane phosphoprotein-43 (GAP-43), chondroitin sulfate proteoglycans (CSPGs) and neurocan were also determined by IHC 14d after ONC. RESULTS GFAP level in the retina and the optic nerve significantly increased 1d after ONC, and reached the peak level 7d post-ONC. Injection of αA-crystallin significantly decreased GFAP level in both the retina and the crush site 3d after ONC, and induced astrocytes architecture remodeling at the crush site. Quantification of retinal ganglion cell (RGC) axons indicated αA-crystallin markedly promoted axon regeneration in ONC rats and enhanced the regenerated axons penetrated into the glial scar. CSPGs and neurocan expression also decreased 14d after αA-crystallin injection. The amplitude (N1-P1) and latency (P1) of F-VEP were also restored. CONCLUSION Our results suggest α-crystallin promotes the axon regeneration of RGCs and suppresses the activation of astrocytes.
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Affiliation(s)
- Wei-Yang Shao
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University, Chongqing 400038, China; Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, China
| | - Xiao Liu
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University, Chongqing 400038, China; Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, China
| | - Xian-Liang Gu
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University, Chongqing 400038, China; Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, China
| | - Xi Ying
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University, Chongqing 400038, China; Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, China
| | - Nan Wu
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University, Chongqing 400038, China; Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, China
| | - Hai-Wei Xu
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University, Chongqing 400038, China; Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, China
| | - Yi Wang
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University, Chongqing 400038, China; Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, China
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13
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Jeyachandran A, Mertens B, McKissick EA, Mitchell CS. Type I Vs. Type II Cytokine Levels as a Function of SOD1 G93A Mouse Amyotrophic Lateral Sclerosis Disease Progression. Front Cell Neurosci 2015; 9:462. [PMID: 26648846 PMCID: PMC4664727 DOI: 10.3389/fncel.2015.00462] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 11/13/2015] [Indexed: 01/01/2023] Open
Abstract
Amyotrophic Lateral Sclerosis (ALS) is a fatal motoneuron disease that is characterized by the degradation of neurons throughout the central nervous system. Inflammation have been cited a key contributor to ALS neurodegeneration, but the timeline of cytokine upregulation remains unresolved. The goal of this study was to temporally examine the correlation between the varying levels of pro-inflammatory type I cytokines (IL-1β, IL-1α, IL-12, TNF-α, and GFAP) and anti-inflammatory type II cytokines (IL-4, IL-6, IL-10) throughout the progression of ALS in the SOD1 G93A mouse model. Cytokine level data from high copy SOD1 G93A transgenic mice was collected from 66 peer-reviewed studies. For each corresponding experimental time point, the ratio of transgenic to wild type (TG/WT) cytokine was calculated. One-way ANOVA and t-tests with Bonferonni correction were used to analyze the data. Meta-analysis was performed for four discrete stages: early, pre-onset, post-onset, and end stage. A significant increase in TG cytokine levels was found when compared to WT cytokine levels across the entire SOD1 G93A lifespan for majority of the cytokines. The rates of change of the individual cytokines, and type I and type II were not significantly different; however, the mean fold change of type I was expressed at significantly higher levels than type II levels across all stages with the difference between the means becoming more pronounced at the end stage. An overexpression of cytokines occurred both before and after the onset of ALS symptoms. The trend between pro-inflammatory type I and type II cytokine mean levels indicate a progressive instability of the dynamic balance between pro- and anti-inflammatory cytokines as anti-inflammatory cytokines fail to mediate the pronounced increase in pro-inflammatory cytokines. Very early immunoregulatory treatment is necessary to successfully interrupt ALS-induced neuroinflammation.
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Affiliation(s)
- Amilia Jeyachandran
- Department of Biomedical Engineering, Georgia Institute of Technology and Emory University Atlanta, GA, USA
| | - Benjamin Mertens
- Department of Biomedical Engineering, Georgia Institute of Technology and Emory University Atlanta, GA, USA
| | - Eric A McKissick
- Department of Biomedical Engineering, Georgia Institute of Technology and Emory University Atlanta, GA, USA
| | - Cassie S Mitchell
- Department of Biomedical Engineering, Georgia Institute of Technology and Emory University Atlanta, GA, USA
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14
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Zhao YY, Yuan Y, Chen Y, Jiang L, Liao RJ, Wang L, Zhang XN, Ohtsu H, Hu WW, Chen Z. Histamine promotes locomotion recovery after spinal cord hemisection via inhibiting astrocytic scar formation. CNS Neurosci Ther 2015; 21:454-62. [PMID: 25620315 PMCID: PMC6495821 DOI: 10.1111/cns.12379] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 12/11/2014] [Accepted: 12/12/2014] [Indexed: 02/07/2023] Open
Abstract
AIM This study investigated whether histamine could play a protective role in pathophysiological response of spinal cord injury (SCI) and regulate the glial scar formation. METHODS Functional assessment and histological analyses were performed to investigate the effect of histamine after SCI. Histidine decarboxylase knockout (HDC(-/-)) mice were used to confirm the action of histamine. Selective antagonists for H1 and H2 receptors were utilized in vivo and in vitro to verify the functional properties of histamine on astrogliosis. RESULTS The local administration of histamine significantly attenuated the tissue damage and glial scar formation after SCI. In particular, the astrogliosis and neurocan expression found around the lesion were significantly suppressed by histamine. Immunofluorescent staining for neurofilament showed that histamine promoted axonal growth across the glial scar. The HDC(-/-) mice, lacking in endogenous histamine, showed lower behavior score, increased lesion size and astrogliosis, as compared with the wild types. The effect of histamine on locomotor recovery and reactive astrogliosis is reversed by H1 receptor antagonist but not H2 receptor antagonist. CONCLUSIONS Our results indicate that histamine significantly improved the chronic locomotor recovery via attenuating astrogliosis after SCI by stimulating histamine H1 receptor. This study highlights a therapeutic potential of histamine and its related drugs for SCI.
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Affiliation(s)
- Yan-Yan Zhao
- Department of Pharmacology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, Zhejiang Province Key Laboratory of Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
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15
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Karve IP, Taylor JM, Crack PJ. The contribution of astrocytes and microglia to traumatic brain injury. Br J Pharmacol 2015; 173:692-702. [PMID: 25752446 DOI: 10.1111/bph.13125] [Citation(s) in RCA: 414] [Impact Index Per Article: 46.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Revised: 02/09/2015] [Accepted: 02/18/2015] [Indexed: 12/13/2022] Open
Abstract
Traumatic brain injury (TBI) represents a major cause of death and disability in developed countries. Brain injuries are highly heterogeneous and can also trigger other neurological complications, including epilepsy, depression and dementia. The initial injury often leads to the development of secondary sequelae; cellular hyperexcitability, vasogenic and cytotoxic oedema, hypoxia-ischaemia, oxidative stress and inflammation, all of which influence expansion of the primary lesion. It is widely known that inflammatory events in the brain following TBI contribute to the widespread cell death and chronic tissue degeneration. Neuroinflammation is a multifaceted response involving a number of cell types, both within the CNS and in the peripheral circulation. Astrocytes and microglia, cells of the CNS, are considered key players in initiating an inflammatory response after injury. These cells are capable of secreting various cytokines, chemokines and growth factors, and following injury to the CNS, undergo changes in morphology. Ultimately, these changes can influence the local microenvironment and thus determine the extent of damage and subsequent repair. This review will focus on the roles of microglia and astrocytes following TBI, highlighting some of the key processes, pathways and mediators involved in this response. Additionally, both the beneficial and the detrimental aspects of these cellular responses will be examined using evidence from animal models and human post-mortem TBI studies.
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Affiliation(s)
- Ila P Karve
- Neuropharmacology Laboratory, Department of Pharmacology, University of Melbourne, Melbourne, Vic., Australia
| | - Juliet M Taylor
- Neuropharmacology Laboratory, Department of Pharmacology, University of Melbourne, Melbourne, Vic., Australia
| | - Peter J Crack
- Neuropharmacology Laboratory, Department of Pharmacology, University of Melbourne, Melbourne, Vic., Australia
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Abstract
Intraventricular hemorrhage (IVH) is a major neurologic complication of prematurity. Pathogenesis of IVH is attributed to intrinsic fragility of germinal matrix vasculature and to the fluctuation in the cerebral blood flow. Germinal matrix exhibits rapid angiogenesis orchestrating formation of immature vessels. Prenatal glucocorticoid exposure remains the most effective means of preventing IVH. Therapies targeted to enhance the stability of the germinal matrix vasculature and minimize fluctuation in the cerebral blood flow might lead to more effective strategies in preventing IVH.
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Affiliation(s)
- Praveen Ballabh
- Department of Pediatrics, Cell Biology and Anatomy, Regional Neonatal Center, New York Medical College, Maria Fareri Children's Hospital, Westchester Medical Center, 100 Woods Road, Valhalla, NY 10595, USA.
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17
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Yuan YM, He C. The glial scar in spinal cord injury and repair. Neurosci Bull 2013; 29:421-35. [PMID: 23861090 DOI: 10.1007/s12264-013-1358-3] [Citation(s) in RCA: 135] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Accepted: 05/03/2013] [Indexed: 12/21/2022] Open
Abstract
Glial scarring following severe tissue damage and inflammation after spinal cord injury (SCI) is due to an extreme, uncontrolled form of reactive astrogliosis that typically occurs around the injury site. The scarring process includes the misalignment of activated astrocytes and the deposition of inhibitory chondroitin sulfate proteoglycans. Here, we first discuss recent developments in the molecular and cellular features of glial scar formation, with special focus on the potential cellular origin of scar-forming cells and the molecular mechanisms underlying glial scar formation after SCI. Second, we discuss the role of glial scar formation in the regulation of axonal regeneration and the cascades of neuro-inflammation. Last, we summarize the physical and pharmacological approaches targeting the modulation of glial scarring to better understand the role of glial scar formation in the repair of SCI.
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Affiliation(s)
- Yi-Min Yuan
- Institute of Neuroscience and Key Laboratory of Molecular Neurobiology of Ministry of Education, Neuroscience Research Center of Changzheng Hospital, Second Military Medical University, Shanghai 200433, China
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18
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Beller JA, Kulengowski B, Kobraei EM, Curinga G, Calulot CM, Bahrami A, Hering TM, Snow DM. Comparison of sensory neuron growth cone and filopodial responses to structurally diverse aggrecan variants, in vitro. Exp Neurol 2013; 247:143-57. [PMID: 23458191 DOI: 10.1016/j.expneurol.2013.02.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Revised: 02/06/2013] [Accepted: 02/18/2013] [Indexed: 12/20/2022]
Abstract
Following spinal cord injury, a regenerating neurite encounters a glial scar enriched in chondroitin sulfate proteoglycans (CSPGs), which presents a major barrier. There are two points at which a neurite makes contact with glial scar CSPGs: initially, filopodia surrounding the growth cone extend and make contact with CSPGs, then the peripheral domain of the entire growth cone makes CSPG contact. Aggrecan is a CSPG commonly used to model the effect CSPGs have on elongating or regenerating neurites. In this study, we investigated filopodia and growth cone responses to contact with structurally diverse aggrecan variants using the common stripe assay. Using time-lapse imaging with 15-s intervals, we measured growth cone area, growth cone width, growth cone length, filopodia number, total filopodia length, and the length of the longest filopodia following contact with aggrecan. Responses were measured after both filopodia and growth cone contact with five different preparations of aggrecan: two forms of aggrecan derived from bovine articular cartilage (purified and prepared using different techniques), recombinant aggrecan lacking chondroitin sulfate side chains (produced in CHO-745 cells) and two additional recombinant aggrecan preparations with varying lengths of chondroitin sulfate side chains (produced in CHO-K1 and COS-7 cells). Responses in filopodia and growth cone behavior differed between the structurally diverse aggrecan variants. Mutant CHO-745 aggrecan (lacking chondroitin sulfate chains) permitted extensive growth across the PG stripe. Filopodia contact with the CHO-745 aggrecan caused a significant increase in growth cone width and filopodia length (112.7% ± 4.9 and 150.9% ± 7.2 respectively, p<0.05), and subsequently upon growth cone contact, growth cone width remained elevated along with a reduction in filopodia number (121.9% ± 4.2; 72.39% ± 6.4, p<0.05). COS-7 derived aggrecan inhibited neurite outgrowth following growth cone contact. Filopodia contact produced an increase in growth cone area and width (126.5% ± 8.1; 150.3% ± 13.31, p<0.001), and while these parameters returned to baseline upon growth cone contact, a reduction in filopodia number and length was observed (73.94% ± 5.8, 75.3% ± 6.2, p<0.05). CHO-K1 derived aggrecan inhibited neurite outgrowth following filopodia contact, and caused an increase in growth cone area and length (157.6% ± 6.2; 117.0% ± 2.8, p<0.001). Interestingly, the two bovine articular cartilage aggrecan preparations differed in their effects on neurite outgrowth. The proprietary aggrecan (BA I, Sigma-Aldrich) inhibited neurites at the point of growth cone contact, while our chemically purified aggrecan (BA II) inhibited neurite outgrowth at the point of filopodia contact. BA I caused a reduction in growth cone width following filopodia contact (91.7% ± 2.5, p<0.05). Upon growth cone contact, there was a further reduction in growth cone width and area (66.4% ± 2.2; 75.6% ± 2.9; p<0.05), as well as reductions in filopodia number, total length, and max length (75.9% ± 5.7, p<0.05; 68.8% ± 6.0; 69.6% ± 3.5, p<0.001). Upon filopodia contact, BA II caused a significant increase in growth cone area, and reductions in filopodia number and total filopodia length (115.9% ± 5.4, p<0.05; 72.5% ± 2.7; 77.7% ± 3.2, p<0.001). In addition, filopodia contact with BA I caused a significant reduction in growth cone velocity (38.6 nm/s ± 1.3 before contact, 17.1 nm/s ± 3.6 after contact). These data showed that neuron morphology and behavior are differentially dependent upon aggrecan structure. Furthermore, the behavioral changes associated with the approaching growth cone may be predictive of inhibition or growth.
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Affiliation(s)
- Justin A Beller
- Spinal Cord and Brain Injury Research Center, and Department of Anatomy and Neurobiology, University of Kentucky, Lexington, KY 40536, USA
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Chong ZZ, Shang YC, Zhang L, Wang S, Maiese K. Mammalian target of rapamycin: hitting the bull's-eye for neurological disorders. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2010; 3:374-91. [PMID: 21307646 PMCID: PMC3154047 DOI: 10.4161/oxim.3.6.14787] [Citation(s) in RCA: 119] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The mammalian target of rapamycin (mTOR) and its associated cell signaling pathways have garnered significant attention for their roles in cell biology and oncology. Interestingly,the explosion of information in this field has linked mTOR to neurological diseases with promising initial studies. mTOR, a 289 kDa serine/threonine protein kinase, plays an important role in cell growth and proliferation and is activated through phosphorylation in response to growth factors, mitogens and hormones. Growth factors, amino acids, cellular nutrients and oxygen deficiency can downregulate mTOR activity. The function of mTOR signaling is mediated primarily through two mTOR complexes: mTORC1 and mTORC2. mTORC1 initiates cap-dependent protein translation, a rate-limiting step of protein synthesis, through the phosphorylation of the targets eukaryotic initiation factor 4E-binding protein 1 (4EBP1) and p70 ribosomal S6 kinase (p70S6K). In contrast, mTORC2 regulates development of the cytoskeleton and also controls cell survival. Although closely tied to tumorigenesis, mTOR and the downstream signaling pathways are significantly involved in the central nervous system (CNS) with synaptic plasticity, memory retention, neuroendocrine regulation associated with food intake and puberty and modulation of neuronal repair following injury. The signaling pathways of mTOR also are believed to be a significant component in a number of neurological diseases, such as Alzheimer disease, Parkinson disease and Huntington disease, tuberous sclerosis, neurofibromatosis, fragile X syndrome, epilepsy, traumatic brain injury and ischemic stroke. Here we describe the role of mTOR in the CNS and illustrate the potential for new strategies directed against neurological disorders.
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Affiliation(s)
- Zhao Zhong Chong
- Department of Neurology and Neurosciences, Cancer Center, University of Medicine and Dentistry - New Jersey Medical School, Newark, NJ, USA
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20
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Xin H, Li Y, Shen LH, Liu X, Wang X, Zhang J, Pourabdollah-Nejad D S, Zhang C, Zhang L, Jiang H, Zhang ZG, Chopp M. Increasing tPA activity in astrocytes induced by multipotent mesenchymal stromal cells facilitate neurite outgrowth after stroke in the mouse. PLoS One 2010; 5:e9027. [PMID: 20140248 PMCID: PMC2815778 DOI: 10.1371/journal.pone.0009027] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2009] [Accepted: 01/11/2010] [Indexed: 10/31/2022] Open
Abstract
We demonstrate that tissue plasminogen activator (tPA) and its inhibitors contribute to neurite outgrowth in the central nervous system (CNS) after treatment of stroke with multipotent mesenchymal stromal cells (MSCs). In vivo, administration of MSCs to mice subjected to middle cerebral artery occlusion (MCAo) significantly increased activation of tPA and downregulated PAI-1 levels in the ischemic boundary zone (IBZ) compared with control PBS treated mice, concurrently with increases of myelinated axons and synaptophysin. In vitro, MSCs significantly increased tPA levels and concomitantly reduced plasminogen activator inhibitor 1 (PAI-1) expression in astrocytes under normal and oxygen and glucose deprivation (OGD) conditions. ELISA analysis of conditioned medium revealed that MSCs stimulated astrocytes to secrete tPA. When primary cortical neurons were cultured in the conditioned medium from MSC co-cultured astrocytes, these neurons exhibited a significant increase in neurite outgrowth compared to conditioned medium from astrocytes alone. Blockage of tPA with a neutralizing antibody or knock-down of tPA with siRNA significantly attenuated the effect of the conditioned medium on neurite outgrowth. Addition of recombinant human tPA into cortical neuronal cultures also substantially enhanced neurite outgrowth. Collectively, these in vivo and in vitro data suggest that the MSC mediated increased activation of tPA in astrocytes promotes neurite outgrowth after stroke.
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Affiliation(s)
- Hongqi Xin
- Department of Neurology, Henry Ford Health System, Detroit, Michigan, United States of America
| | - Yi Li
- Department of Neurology, Henry Ford Health System, Detroit, Michigan, United States of America
| | - Li Hong Shen
- Department of Neurology, Henry Ford Health System, Detroit, Michigan, United States of America
| | - Xianshuang Liu
- Department of Neurology, Henry Ford Health System, Detroit, Michigan, United States of America
| | - Xinli Wang
- Department of Neurology, Henry Ford Health System, Detroit, Michigan, United States of America
| | - Jing Zhang
- Department of Neurology, Henry Ford Health System, Detroit, Michigan, United States of America
| | | | - Chunling Zhang
- Department of Neurology, Henry Ford Health System, Detroit, Michigan, United States of America
| | - Li Zhang
- Department of Neurology, Henry Ford Health System, Detroit, Michigan, United States of America
| | - Hao Jiang
- Department of Neurology, Henry Ford Health System, Detroit, Michigan, United States of America
| | - Zheng Gang Zhang
- Department of Neurology, Henry Ford Health System, Detroit, Michigan, United States of America
| | - Michael Chopp
- Department of Neurology, Henry Ford Health System, Detroit, Michigan, United States of America
- Department of Physics, Oakland University, Rochester, Michigan, United States of America
- * E-mail:
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21
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Ting KK, Brew BJ, Guillemin GJ. Effect of quinolinic acid on human astrocytes morphology and functions: implications in Alzheimer's disease. J Neuroinflammation 2009; 6:36. [PMID: 20003262 PMCID: PMC2797503 DOI: 10.1186/1742-2094-6-36] [Citation(s) in RCA: 113] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2009] [Accepted: 12/10/2009] [Indexed: 02/06/2023] Open
Abstract
The excitotoxin quinolinic acid (QUIN) is synthesized through the kynurenine pathway (KP) by activated monocyte lineage cells. QUIN is likely to play a role in the pathogenesis of several major neuroinflammatory diseases including Alzheimer's disease (AD). The presence of reactive astrocytes, astrogliosis, increased oxidative stress and inflammatory cytokines are important pathological hallmarks of AD. We assessed the stimulatory effects of QUIN at low physiological to high excitotoxic concentrations in comparison with the cytokines commonly associated with AD including IFN-γ and TNF-α on primary human astrocytes. We found that QUIN induces IL-1β expression, a key mediator in AD pathogenesis, in human astrocytes. We also explored the effect of QUIN on astrocyte morphology and functions. At low concentrations, QUIN treatment induced concomitantly a marked increase in glial fibrillary acid protein levels and reduction in vimentin levels compared to controls; features consistent with astrogliosis. At pathophysiological concentrations QUIN induced a switch between structural protein expressions in a dose dependent manner, increasing VIM and concomitantly decreasing GFAP expression. Glutamine synthetase (GS) activity was used as a functional metabolic test for astrocytes. We found a significant dose-dependent reduction in GS activity following QUIN treatment. All together, this study showed that QUIN is an important factor for astroglial activation, dysregulation and cell death with potential relevance to AD and other neuroinflammatory diseases.
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Affiliation(s)
- Ka Ka Ting
- St Vincent's Centre for Applied Medical Research, St Vincent's Hospital, Sydney, Australia.
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22
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Hirko AC, Dallasen R, Jomura S, Xu Y. Modulation of inflammatory responses after global ischemia by transplanted umbilical cord matrix stem cells. Stem Cells 2008; 26:2893-901. [PMID: 18719227 DOI: 10.1634/stemcells.2008-0075] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Rat umbilical cord matrix (RUCM) cells are stem-cell-like cells and have been shown to reduce neuronal loss in the selectively vulnerable brain regions after cardiac arrest (CA). Here, we investigate whether this protection is mediated by the RUCM cells' modulation of the postischemia inflammation responses, which have long been implicated as a secondary mechanism of injury following ischemia. Brain sections were examined immunohistochemically for glial fibrillary acidic protein (GFAP), vimentin, and nestin as markers for astroglia and reactive astrogliosis, Ricinus Communis Agglutinin-1 (RCA-1) as a marker for microglia, and Ki67 as a marker for cell proliferation. Rats were randomly assigned to six experimental groups: (1) 8-minute CA without treatment, (2) 8-minute CA pre-treated with culture medium injection, (3) 8-minute CA pre-treated with RUCM cells, (4) sham-operated CA, (5) medium injection without CA, and (6) RUCM cell transplantation without CA. Groups 1-3 have significantly higher Ki67(+) cell counts and higher GFAP(+) immunoreactivity in the hippocampal Cornu Ammonis layer 1 (CA1) region compared to groups 4-6, irrespective of treatment. Groups 1 and 2 have highly elevated GFAP(+), vimentin(+), and nestin(+) immunoreactivity, indicating reactive astrogliosis. Strikingly, RUCM cell treatment nearly completely inhibited the appearance of vimentin(+) and greatly reduced nestin(+) reactive astrocytes. RUCM cell treatment also greatly reduced RCA-1 staining, which is found to strongly correlate with the neuronal loss in the CA1 region. Our study indicates that treatment with stem-cell-like RUCM cells modulates the inflammatory response to global ischemia and renders neuronal protection by preventing permanent damage to the selectively vulnerable astrocytes in the CA1 region. Disclosure of potential conflicts of interest is found at the end of this article.
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Affiliation(s)
- Aaron C Hirko
- Departments of Anesthesiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15260, USA
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Ramu J, Herrera J, Grill R, Bockhorst T, Narayana P. Brain fiber tract plasticity in experimental spinal cord injury: diffusion tensor imaging. Exp Neurol 2008; 212:100-7. [PMID: 18482724 PMCID: PMC2453245 DOI: 10.1016/j.expneurol.2008.03.018] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2008] [Revised: 03/10/2008] [Accepted: 03/12/2008] [Indexed: 11/16/2022]
Abstract
Diffusion tensor imaging (DTI) and immunohistochemistry were performed in spinal cord injured rats to understand the basis for activation of multiple regions in the brain observed in functional magnetic resonance imaging (fMRI) studies. The measured fractional anisotropy (FA), a scalar measure of diffusion anisotropy, along the region encompassing corticospinal tracts (CST) indicates significant differences between control and injured groups in the 3 to 4 mm area posterior to bregma that correspond to internal capsule and cerebral peduncle. Additionally, DTI-based tractography in injured animals showed increased number of fibers that extend towards the cortex terminating in the regions that were activated in fMRI. Both the internal capsule and cerebral peduncle demonstrated an increase in GFAP-immunoreactivity compared to control animals. GAP-43 expression also indicates plasticity in the internal capsule. These studies suggest that the previously observed multiple regions of activation in spinal cord injury are, at least in part, due to the formation of new fibers.
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Affiliation(s)
- Jaivijay Ramu
- Department of Diagnostic and Interventional Imaging, University of Texas Medical School at Houston, 6431 Fannin Street, Houston, Texas 77030
| | - Juan Herrera
- Department of Diagnostic and Interventional Imaging, University of Texas Medical School at Houston, 6431 Fannin Street, Houston, Texas 77030
| | - Raymond Grill
- Department of Neurosurgery, University of Texas Medical School at Houston, 6431 Fannin Street, Houston, Texas 77030
| | - Tobias Bockhorst
- Department of Diagnostic and Interventional Imaging, University of Texas Medical School at Houston, 6431 Fannin Street, Houston, Texas 77030
| | - Ponnada Narayana
- Department of Diagnostic and Interventional Imaging, University of Texas Medical School at Houston, 6431 Fannin Street, Houston, Texas 77030
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24
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Combined treatment using peripheral nerve graft and FGF-1: changes to the glial environment and differential macrophage reaction in a complete transected spinal cord. Neurosci Lett 2007; 433:163-9. [PMID: 18291581 DOI: 10.1016/j.neulet.2007.11.067] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2007] [Revised: 11/07/2007] [Accepted: 11/21/2007] [Indexed: 11/21/2022]
Abstract
We used a complete spinal cord transection model in which the T8 spinal segment was removed to study the effect of combined treatment of peripheral nerve graft and application of FGF-1 on the glial environment. The combined treatment resulted in reduced astrocytic glial scarring, reactive macrophage gliosis, and inhibitory proteoglycan in the back-degenerated white matter tract. While the macrophage activities in the back-degenerative tract were down-regulated, those in the grafted peripheral nerves and in the distal Wallerian degenerative tracts were not. We concluded that the combined treatment changed the glial environment in the back-degenerative tract, and differentially regulated the macrophage activities in the system, in favor of CNS regeneration.
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25
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Tetzlaff J, Tanzer L, Jones KJ. Cellular localization of androgen and estrogen receptors in mouse-derived motoneuron hybrid cells and mouse facial motoneurons. Dev Neurobiol 2007; 67:1362-70. [PMID: 17638386 DOI: 10.1002/dneu.20505] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The ability of gonadal steroid hormones to augment axonal regeneration after peripheral nerve injury has been well established in rat and hamster motoneuron systems, and provides a foundation for the use of these agents as neurotherapeutics. With the advent of mouse genetics and the availability of transgenic and knockout mice, the use of mice in studies of neuroprotection is growing. It has recently been demonstrated that both androgens and estrogens rescue motoneurons (MN) from injury in mouse-derived motoneuron hybrid cells in vitro and mouse facial motoneurons (FMN) in vivo (Tetzlaff et al. [2006] J Mol Neurosci 28:53-64). To elucidate the molecular mechanisms of these effects, the present study examined the cellular localization of androgen and estrogen receptors in mouse MN in vitro and in vivo. Immunoblotting and immunocytochemistry studies established the presence of androgen receptor (AR) and estrogen receptor alpha/beta in immortalized mouse motoneuron hybrid cells and AR and estrogen receptor alpha in mouse FMN.
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Affiliation(s)
- Julie Tetzlaff
- Neuroscience Graduate Program, Loyola University Chicago, Maywood, Illinois 60153, USA
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26
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Bai L, Caplan A, Lennon D, Miller RH. Human mesenchymal stem cells signals regulate neural stem cell fate. Neurochem Res 2006; 32:353-62. [PMID: 17191131 DOI: 10.1007/s11064-006-9212-x] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2006] [Accepted: 10/23/2006] [Indexed: 01/01/2023]
Abstract
Neural stem cells (NSCs) differentiate into neurons, astrocytes and oligodendrocytes depending on their location within the central nervous system (CNS). The cellular and molecular cues mediating end-stage cell fate choices are not completely understood. The retention of multipotent NSCs in the adult CNS raises the possibility that selective recruitment of their progeny to specific lineages may facilitate repair in a spectrum of neuropathological conditions. Previous studies suggest that adult human bone marrow derived mesenchymal stem cells (hMSCs) improve functional outcome after a wide range of CNS insults, probably through their trophic influence. In the context of such trophic activity, here we demonstrate that hMSCs in culture provide humoral signals that selectively promote the genesis of neurons and oligodendrocytes from NSCs. Cell-cell contacts were less effective and the proportion of hMSCs that could be induced to express neural characteristics was very small. We propose that the selective promotion of neuronal and oligodendroglial fates in neural stem cell progeny is responsible for the ability of MSCs to enhance recovery after a wide range of CNS injuries.
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Affiliation(s)
- Lianhua Bai
- Centers for Stem Cells and Regenerative Medicine, Translational Neuroscience, Department of Neurosciences, Case School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
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27
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Taupin P. Adult neural stem cells, neurogenic niches, and cellular therapy. ACTA ACUST UNITED AC 2006; 2:213-9. [PMID: 17625257 DOI: 10.1007/s12015-006-0049-0] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/1999] [Revised: 11/30/1999] [Accepted: 11/30/1999] [Indexed: 01/29/2023]
Abstract
Niches are specialized microenvironments that regulate stem cells activity. In the nervous system, during development, niches control neural stem cells (NSCs) maturation and the formation of the neuronal network. In the adult, neurogenesis occurs in discrete areas of the brain, the subventricular zone and the hippocampus, where neurogenic niches have been identified and characterized. These niches, an angiogenic and an astroglial niche, control NSCs self-renewal and differentiation. Although the molecular and cellular mechanisms underlying the interactions between NSCs and their environment remain to be elucidated, neurogenic niches share similar developmentally conserved pathways with other niches. It is hypothesized that neurogenic niches underlie the properties and functions of NSCs in the adult central nervous system. Hence, neurogenic niches may not only hold the key to our understanding of neurogenesis in the adult brain, but also of the developmental potential of adult NSCs, and their potential for cellular therapy.
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28
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Tetzlaff JE, Huppenbauer CB, Tanzer L, Alexander TD, Jones KJ. Motoneuron injury and repair: New perspectives on gonadal steroids as neurotherapeutics. J Mol Neurosci 2006; 28:53-64. [PMID: 16632875 DOI: 10.1385/jmn:28:1:53] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2005] [Revised: 11/30/1999] [Accepted: 06/28/2005] [Indexed: 12/26/2022]
Abstract
In this review, we will summarize recent work from our laboratory on the role of gonadal steroids as neuroprotective agents in motoneuron viability following cell stress. Three motoneuron models will be discussed: developing axotomized hamster facial motoneurons (FMNs); adult axotomized mouse FMNs; and immortalized, cultured mouse spinal motoneurons subjected to heat shock. New work on two relevant motoneuron proteins, the survival of motor neuron protein, and neuritin or candidate plasticity-related gene 15, indicates differential steroid regulation of these two proteins after axotomy. The concept of gonadal steroids as cellular stress correction factors and the implications of this for acute neurological injury situations will be presented as well.
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Affiliation(s)
- Julie E Tetzlaff
- Department of Cell Biology, Neurobiology, and Anatomy, Loyola University of Chicago, Stritch School of Medicine, Maywood, IL 60153, USA
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29
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El-Khoury N, Braun A, Hu F, Pandey M, Nedergaard M, Lagamma EF, Ballabh P. Astrocyte end-feet in germinal matrix, cerebral cortex, and white matter in developing infants. Pediatr Res 2006; 59:673-9. [PMID: 16627880 DOI: 10.1203/01.pdr.0000214975.85311.9c] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Astrocyte end-feet ensheathe blood vessels in the brain and are believed to provide structural integrity to the cerebral vasculature. We sought to determine in developing infants whether the coverage of blood vessels by astrocyte end-feet is decreased in germinal matrix (GM) compared with cerebral cortex and white matter (WM), which may cause fragility of the GM vasculature. Therefore, we evaluated the perivascular coverage by astrocyte end-feet in these areas. We double-labeled the brain sections with astroglial markers [glial fibrillary acidic protein (GFAP), aquaporin-4 (AQP4), and S-100beta] and a vascular marker, laminin. Perivascular coverage by GFAP+ astrocyte end-feet increased consistently as a function of gestational age (GA) in cortex and WM from 19 to 40 wk. Compared with GFAP, AQP4+ astrocyte end-feet developed at an earlier GA, ensheathing about 63% of blood vessels for 23-40 wk in cortex, WM, and GM. Coverage by GFAP+ perivascular end-feet was decreased in GM compared with cortex and WM from 23 to 34 wk. There was no difference in the coverage by AQP4+ end-feet among the three areas in these infants. The expression of AQP4, a water channel molecule, in the astrocyte end-feet was not significantly different between premature and mature infants, suggesting similar risk of brain edema in preterm and term infants in pathologic conditions. More importantly, the lesser degree of GFAP expression in astrocyte end-feet of GM compared with cortex and WM may reflect a cytoskeletal structural difference that contributes to the fragility of GM vasculature and propensity to hemorrhage.
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Affiliation(s)
- Nadine El-Khoury
- Department of Pediatrics, Westchester Medical Center, New York Medical College, Valhalla, New York 10595, USA
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