1
|
Ghanbari A, Ghasemi S, Khaleghian A. Effects of swimming exercise on neuropathic pain in a rat model: role of glutamate. Neurol Res 2024; 46:330-338. [PMID: 38323336 DOI: 10.1080/01616412.2024.2313901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 01/30/2024] [Indexed: 02/08/2024]
Abstract
OBJECTIVE The pain-reducing effects of the exercise were exerted through different mechanisms. Knowing more clear mechanisms helps to find more approach that is therapeutic. The objective of the present study is the evaluation of cerebrospinal fluid (CSF) glutamate level alteration in neuropathic pain rats and whether physical activity could modulate it. METHODS In the present study 104 male Wistar rats weighing 180-220 g were randomly divided into 4 groups (Sham, Sham + Exe, Neuropathy, and Neuropathy + Exe) which in turn each group subdivided into 4 groups according to time points for behavioral testing and CSF sampling (Baseline, 2 weeks, 3 weeks, and 4 weeks). To induction of neuropathy (by chronic constriction injury,), after anesthetizing with a mixture of ketamine (80 mg/kg) and xylazine (10 mg/kg), the animal's right sciatic nerve was exposed and was ligated using four movable catgut chromic suture 4/0. The exercise protocol included 25 min of daily swimming, 5 days a week for 4 weeks. Thermal hyperalgesia and mechanical tactile threshold were detected using the plantar test and Von Frey filaments, respectively. CSF glutamate level was determined using high-performance liquid chromatography. RESULTS Findings indicated that mechanical and thermal thresholds significantly (p < 0.01, p < 0.05 respectively) decreased in the neuropathy group against that in sham groups. On the other hand, exercise significantly increased mechanical tactile threshold (p < 0.0012) and thermal threshold (p < 0.05) compared to the neuropathy group. Moreover, CSF glutamate level prominently (p < 0.01) was increased in the neuropathy group compared to the sham group, and swimming exercise significantly (p < 0.001) reduced it. IN CONCLUSION The present findings provide new evidence showing that medium-intensity swimming exercise attenuates pain-like behaviors in neuropathic pain animals, which is possibly due to decreasing CSF glutamate level and its neurotransmission.
Collapse
Affiliation(s)
- Ali Ghanbari
- Research Center of Physiology, Semnan University of Medical Sciences, Semnan, Iran
| | - Sahar Ghasemi
- Student Research Committee, Semnan University of Medical Sciences, Semnan, Iran
| | - Ali Khaleghian
- Department of Biochemistry, Faculty of Medicine, Semnan University of Medical Sciences, Semnan, Iran
| |
Collapse
|
2
|
Li YK, Zhang YY, Lin J, Liu YJ, Li YL, Feng YH, Zhao JS, Zhou C, Liu F, Shen JF. Metabotropic glutamate receptor 5-mediated inhibition of inward-rectifying K + channel 4.1 contributes to orofacial ectopic mechanical allodynia following inferior alveolar nerve transection in male mice. J Neurosci Res 2023; 101:1170-1187. [PMID: 36807930 DOI: 10.1002/jnr.25181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 01/20/2023] [Accepted: 01/31/2023] [Indexed: 02/20/2023]
Abstract
Inward-rectifying K+ channel 4.1 (Kir4.1), which regulates the electrophysiological properties of neurons and glia by affecting K+ homeostasis, plays a critical role in neuropathic pain. Metabotropic glutamate receptor 5 (mGluR5) regulates the expression of Kir4.1 in retinal Müller cells. However, the role of Kir4.1 and its expressional regulatory mechanisms underlying orofacial ectopic allodynia remain unclear. This study aimed to investigate the biological roles of Kir4.1 and mGluR5 in the trigeminal ganglion (TG) in orofacial ectopic mechanical allodynia and the role of mGluR5 in Kir4.1 regulation. An animal model of nerve injury was established via inferior alveolar nerve transection (IANX) in male C57BL/6J mice. Behavioral tests indicated that mechanical allodynia in the ipsilateral whisker pad lasted at least 14 days after IANX surgery and was alleviated by the overexpression of Kir4.1 in the TG, as well as intraganglionic injection of an mGluR5 antagonist (MPEP hydrochloride) or a protein kinase C (PKC) inhibitor (chelerythrine chloride); Conditional knockdown of the Kir4.1 gene downregulated mechanical thresholds in the whisker pad. Double immunostaining revealed that Kir4.1 and mGluR5 were co-expressed in satellite glial cells in the TG. IANX downregulated Kir4.1 and upregulated mGluR5 and phosphorylated PKC (p-PKC) in the TG; Inhibition of mGluR5 reversed the changes in Kir4.1 and p-PKC that were induced by IANX; Inhibition of PKC activation reversed the downregulation of Kir4.1 expression caused by IANX (p < .05). In conclusion, activation of mGluR5 in the TG after IANX contributed to orofacial ectopic mechanical allodynia by suppressing Kir4.1 via the PKC signaling pathway.
Collapse
Affiliation(s)
- Yi-Ke Li
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, National Center of Stomatology, West China Hospital of Stomatology, Sichuan University, Chengdu, China.,Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Yan-Yan Zhang
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, National Center of Stomatology, West China Hospital of Stomatology, Sichuan University, Chengdu, China.,Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Jiu Lin
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, National Center of Stomatology, West China Hospital of Stomatology, Sichuan University, Chengdu, China.,Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Ya-Jing Liu
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, National Center of Stomatology, West China Hospital of Stomatology, Sichuan University, Chengdu, China.,Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Yue-Ling Li
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, National Center of Stomatology, West China Hospital of Stomatology, Sichuan University, Chengdu, China.,Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Yu-Heng Feng
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, National Center of Stomatology, West China Hospital of Stomatology, Sichuan University, Chengdu, China.,Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Jia-Shuo Zhao
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, National Center of Stomatology, West China Hospital of Stomatology, Sichuan University, Chengdu, China.,Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Cheng Zhou
- Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Center, West China Hospital of Sichuan University, Chengdu, China
| | - Fei Liu
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, National Center of Stomatology, West China Hospital of Stomatology, Sichuan University, Chengdu, China.,Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Jie-Fei Shen
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, National Center of Stomatology, West China Hospital of Stomatology, Sichuan University, Chengdu, China.,Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| |
Collapse
|
3
|
Main Cations and Cellular Biology of Traumatic Spinal Cord Injury. Cells 2022; 11:cells11162503. [PMID: 36010579 PMCID: PMC9406880 DOI: 10.3390/cells11162503] [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: 06/02/2022] [Revised: 08/06/2022] [Accepted: 08/09/2022] [Indexed: 02/08/2023] Open
Abstract
Traumatic spinal cord injury is a life-changing condition with a significant socio-economic impact on patients, their relatives, their caregivers, and even the community. Despite considerable medical advances, there is still a lack of options for the effective treatment of these patients. The major complexity and significant disabling potential of the pathophysiology that spinal cord trauma triggers are the main factors that have led to incremental scientific research on this topic, including trying to describe the molecular and cellular mechanisms that regulate spinal cord repair and regeneration. Scientists have identified various practical approaches to promote cell growth and survival, remyelination, and neuroplasticity in this part of the central nervous system. This review focuses on specific detailed aspects of the involvement of cations in the cell biology of such pathology and on the possibility of repairing damaged spinal cord tissue. In this context, the cellular biology of sodium, potassium, lithium, calcium, and magnesium is essential for understanding the related pathophysiology and also the possibilities to counteract the harmful effects of traumatic events. Lithium, sodium, potassium—monovalent cations—and calcium and magnesium—bivalent cations—can influence many protein–protein interactions, gene transcription, ion channel functions, cellular energy processes—phosphorylation, oxidation—inflammation, etc. For data systematization and synthesis, we used the Preferred Reporting Items for Systematic Reviews and Meta-Analyzes (PRISMA) methodology, trying to make, as far as possible, some order in seeing the “big forest” instead of “trees”. Although we would have expected a large number of articles to address the topic, we were still surprised to find only 51 unique articles after removing duplicates from the 207 articles initially identified. Our article integrates data on many biochemical processes influenced by cations at the molecular level to understand the real possibilities of therapeutic intervention—which must maintain a very narrow balance in cell ion concentrations. Multimolecular, multi-cellular: neuronal cells, glial cells, non-neuronal cells, but also multi-ionic interactions play an important role in the balance between neuro-degenerative pathophysiological processes and the development of effective neuroprotective strategies. This article emphasizes the need for studying cation dynamics as an important future direction.
Collapse
|
4
|
Soubannier V, Chaineau M, Gursu L, Haghi G, Franco Flores AK, Rouleau G, Durcan TM, Stifani S. Rapid Generation of Ventral Spinal Cord-like Astrocytes from Human iPSCs for Modeling Non-Cell Autonomous Mechanisms of Lower Motor Neuron Disease. Cells 2022; 11:cells11030399. [PMID: 35159209 PMCID: PMC8834281 DOI: 10.3390/cells11030399] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 01/16/2022] [Accepted: 01/21/2022] [Indexed: 12/26/2022] Open
Abstract
Astrocytes play important roles in the function and survival of neuronal cells. Dysfunctions of astrocytes are associated with numerous disorders and diseases of the nervous system, including motor neuron diseases such as amyotrophic lateral sclerosis (ALS). Human-induced pluripotent stem cell (iPSC)-based approaches are becoming increasingly important for the study of the mechanisms underlying the involvement of astrocytes in non-cell autonomous processes of motor neuron degeneration in ALS. These studies must account for the molecular and functional diversity among astrocytes in different regions of the brain and spinal cord. It is essential that the most pathologically relevant astrocyte preparations are used when investigating non-cell autonomous mechanisms of either upper or lower motor neuron degeneration in ALS. Here, we describe the efficient and streamlined generation of human iPSC-derived astrocytes with molecular and biological properties similar to physiological astrocytes in the ventral spinal cord. These induced astrocytes exhibit spontaneous and ATP-induced calcium transients, and lack signs of overt activation. Human iPSC-derived astrocytes with ventral spinal cord features offer advantages over more generic astrocyte preparations for the study of both ventral spinal cord astrocyte biology and the involvement of astrocytes in mechanisms of lower motor neuron degeneration in ALS.
Collapse
Affiliation(s)
- Vincent Soubannier
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montreal, QC H3A 2B4, Canada; (V.S.); (G.R.); (T.M.D.)
- Early Drug Discovery Unit, Montreal Neurological Institute-Hospital, McGill University, Montreal, QC H3A 2B4, Canada; (M.C.); (L.G.); (G.H.); (A.K.F.F.)
| | - Mathilde Chaineau
- Early Drug Discovery Unit, Montreal Neurological Institute-Hospital, McGill University, Montreal, QC H3A 2B4, Canada; (M.C.); (L.G.); (G.H.); (A.K.F.F.)
| | - Lale Gursu
- Early Drug Discovery Unit, Montreal Neurological Institute-Hospital, McGill University, Montreal, QC H3A 2B4, Canada; (M.C.); (L.G.); (G.H.); (A.K.F.F.)
| | - Ghazal Haghi
- Early Drug Discovery Unit, Montreal Neurological Institute-Hospital, McGill University, Montreal, QC H3A 2B4, Canada; (M.C.); (L.G.); (G.H.); (A.K.F.F.)
| | - Anna Kristyna Franco Flores
- Early Drug Discovery Unit, Montreal Neurological Institute-Hospital, McGill University, Montreal, QC H3A 2B4, Canada; (M.C.); (L.G.); (G.H.); (A.K.F.F.)
| | - Guy Rouleau
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montreal, QC H3A 2B4, Canada; (V.S.); (G.R.); (T.M.D.)
| | - Thomas M. Durcan
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montreal, QC H3A 2B4, Canada; (V.S.); (G.R.); (T.M.D.)
- Early Drug Discovery Unit, Montreal Neurological Institute-Hospital, McGill University, Montreal, QC H3A 2B4, Canada; (M.C.); (L.G.); (G.H.); (A.K.F.F.)
| | - Stefano Stifani
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montreal, QC H3A 2B4, Canada; (V.S.); (G.R.); (T.M.D.)
- Correspondence:
| |
Collapse
|
5
|
Dynamic expression of homeostatic ion channels in differentiated cortical astrocytes in vitro. Pflugers Arch 2021; 474:243-260. [PMID: 34734327 PMCID: PMC8766406 DOI: 10.1007/s00424-021-02627-x] [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: 06/09/2021] [Revised: 09/02/2021] [Accepted: 09/24/2021] [Indexed: 11/16/2022]
Abstract
The capacity of astrocytes to adapt their biochemical and functional features upon physiological and pathological stimuli is a fundamental property at the basis of their ability to regulate the homeostasis of the central nervous system (CNS). It is well known that in primary cultured astrocytes, the expression of plasma membrane ion channels and transporters involved in homeostatic tasks does not closely reflect the pattern observed in vivo. The individuation of culture conditions that promote the expression of the ion channel array found in vivo is crucial when aiming at investigating the mechanisms underlying their dynamics upon various physiological and pathological stimuli. A chemically defined medium containing growth factors and hormones (G5) was previously shown to induce the growth, differentiation, and maturation of primary cultured astrocytes. Here we report that under these culture conditions, rat cortical astrocytes undergo robust morphological changes acquiring a multi-branched phenotype, which develops gradually during the 2-week period of culturing. The shape changes were paralleled by variations in passive membrane properties and background conductance owing to the differential temporal development of inwardly rectifying chloride (Cl−) and potassium (K+) currents. Confocal and immunoblot analyses showed that morphologically differentiated astrocytes displayed a large increase in the expression of the inward rectifier Cl− and K+ channels ClC-2 and Kir4.1, respectively, which are relevant ion channels in vivo. Finally, they exhibited a large diminution of the intermediate filaments glial fibrillary acidic protein (GFAP) and vimentin which are upregulated in reactive astrocytes in vivo. Taken together the data indicate that long-term culturing of cortical astrocytes in this chemical-defined medium promotes a quiescent functional phenotype. This culture model could aid to address the regulation of ion channel expression involved in CNS homeostasis in response to physiological and pathological challenges.
Collapse
|
6
|
Li Z, Wang Q, Hu H, Zheng W, Gao C. Research advances of biomaterials-based microenvironment-regulation therapies for repair and regeneration of spinal cord injury. Biomed Mater 2021; 16. [PMID: 34384071 DOI: 10.1088/1748-605x/ac1d3c] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Accepted: 08/12/2021] [Indexed: 12/15/2022]
Abstract
Traumatic spinal cord injury (SCI) usually results in restricted behaviour recovery and even life-changing paralysis, accompanied with numerous complications. Pathologically, the initial injuries trigger a series of secondary injuries, leading to an expansion of lesion site, a mass of neuron loss, and eventual failure of endogenous axon regeneration. As the advances rapidly spring up in regenerative medicine and tissue engineering biomaterials, regulation of these secondary injuries becomes possible, shedding a light on normal functional restoration. The successful tissue regeneration lies in proper regulation of the inflammatory microenvironment, including the inflammatory immune cells and inflammatory factors that lead to oxidative stress, inhibitory glial scar and neuroexcitatory toxicity. Specifically, the approaches based on microenvironment-regulating biomaterials have shown great promise in the repair and regeneration of SCI. In this review, the pathological inflammatory microenvironments of SCI are discussed, followed by the introduction of microenvironment-regulating biomaterials in terms of their impressive therapeutic effect in attenuation of secondary inflammation and promotion of axon regrowth. With the emphasis on regulating secondary events, the biomaterials for SCI treatment will become promising for clinical applications.
Collapse
Affiliation(s)
- Ziming Li
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, People's Republic of China
| | - Qiaoxuan Wang
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, People's Republic of China
| | - Haijun Hu
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, People's Republic of China
| | - Weiwei Zheng
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, People's Republic of China
| | - Changyou Gao
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, People's Republic of China.,Dr Li Dak Sum and Yip Yio Chin Center for Stem Cell and Regenerative Medicine, Zhejiang University, Hangzhou, People's Republic of China
| |
Collapse
|
7
|
Tan H, Tang Y, Li J, He T, Zhou M, Hu S. Prognosis Evaluation Using 18F-Alfatide II PET in a Rat Model of Spinal Cord Injury Treated With Estrogen. Mol Imaging 2021; 19:1536012120909199. [PMID: 32129146 PMCID: PMC7057400 DOI: 10.1177/1536012120909199] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Spinal cord injury (SCI) leads to severe dysfunction below injured segment and poses a great pressure to the individual and society. In this study, we applied 18F-alfatide II positron emission tomography/computed tomography (PET/CT) to monitor angiogenesis in an SCI model after estrogen (E2) treatment, as well as to evaluate the prognosis in a noninvasive manner. The SCI model was established with male rats and the rats were randomly divided into E2-treated group (SCI + E2) and E2-untreated group (SCI). Sham group was also used as control (Sham). The angiogenesis after SCI was monitored by 18F-alfatide II PET/CT and verified by immunofluorescence of CD31 and CD61. We also evaluated the level of E2 and growth-associated protein 43 (GAP43) by enzyme-linked immunosorbent assay. Finally, Basso, Beattie, and Bresnahan (BBB) scores were determined to evaluate the exercise capacity of the rats in all 3 groups. Our results showed that the BBB score of SCI + E2 group was significantly different from that of SCI group (P < .05) and Sham group (P < .01). The uptake of 18F-alfatide II was positively correlated with the expression level of GAP43, both of which reached the peak at day 7 after injury. CD31 and CD61 immunostaining further verified increased angiogenesis in E2-treated SCI lesions. We concluded that 18F-alfatide II PET/CT can monitor the angiogenesis status after SCI in vivo and it may help clinician predict the progression of patients with SCI. This may benefit the study of vascular repair after SCI and provide a tool for evaluation of SCI treatment in clinical practices.
Collapse
Affiliation(s)
- Hongpei Tan
- PET Center of Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Yongxiang Tang
- PET Center of Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Jian Li
- PET Center of Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Tingting He
- Department of Radiology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Ming Zhou
- PET Center of Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Shuo Hu
- PET Center of Xiangya Hospital, Central South University, Changsha, Hunan, China.,National Clinical Research Center for Geriatric Disorders (XIANGYA), Changsha, Hunan, China
| |
Collapse
|
8
|
Verhoog QP, Holtman L, Aronica E, van Vliet EA. Astrocytes as Guardians of Neuronal Excitability: Mechanisms Underlying Epileptogenesis. Front Neurol 2020; 11:591690. [PMID: 33324329 PMCID: PMC7726323 DOI: 10.3389/fneur.2020.591690] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 10/26/2020] [Indexed: 12/11/2022] Open
Abstract
Astrocytes are key homeostatic regulators in the central nervous system and play important roles in physiology. After brain damage caused by e.g., status epilepticus, traumatic brain injury, or stroke, astrocytes may adopt a reactive phenotype. This process of reactive astrogliosis is important to restore brain homeostasis. However, persistent reactive astrogliosis can be detrimental for the brain and contributes to the development of epilepsy. In this review, we will focus on physiological functions of astrocytes in the normal brain as well as pathophysiological functions in the epileptogenic brain, with a focus on acquired epilepsy. We will discuss the role of astrocyte-related processes in epileptogenesis, including reactive astrogliosis, disturbances in energy supply and metabolism, gliotransmission, and extracellular ion concentrations, as well as blood-brain barrier dysfunction and dysregulation of blood flow. Since dysfunction of astrocytes can contribute to epilepsy, we will also discuss their role as potential targets for new therapeutic strategies.
Collapse
Affiliation(s)
- Quirijn P. Verhoog
- Leiden Academic Center for Drug Research, Leiden University, Leiden, Netherlands
- Department of Neuropathology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Linda Holtman
- Leiden Academic Center for Drug Research, Leiden University, Leiden, Netherlands
| | - Eleonora Aronica
- Department of Neuropathology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
- Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, Netherlands
| | - Erwin A. van Vliet
- Department of Neuropathology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
- Center for Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, Netherlands
| |
Collapse
|
9
|
González P, González-Fernández C, Campos-Martín Y, Mollejo M, Carballosa-Gautam M, Marcillo A, Norenberg M, Rodríguez FJ. Frizzled 1 and Wnt1 as new potential therapeutic targets in the traumatically injured spinal cord. Cell Mol Life Sci 2020; 77:4631-4662. [PMID: 31900623 PMCID: PMC11104978 DOI: 10.1007/s00018-019-03427-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 11/21/2019] [Accepted: 12/13/2019] [Indexed: 12/11/2022]
Abstract
Despite the experimental evidence pointing to a significant role of the Wnt family of proteins in physiological and pathological rodent spinal cord functioning, its potential relevance in the healthy and traumatically injured human spinal cord as well as its therapeutic potential in spinal cord injury (SCI) are still poorly understood. To get further insight into these interesting issues, we first demonstrated by quantitative Real-Time PCR and simple immunohistochemistry that detectable mRNA expression of most Wnt components, as well as protein expression of all known Wnt receptors, can be found in the healthy human spinal cord, supporting its potential involvement in human spinal cord physiology. Moreover, evaluation of Frizzled (Fz) 1 expression by double immunohistochemistry showed that its spatio-temporal and cellular expression pattern in the traumatically injured human spinal cord is equivalent to that observed in a clinically relevant model of rat SCI and suggests its potential involvement in SCI progression/outcome. Accordingly, we found that long-term lentiviral-mediated overexpression of the Fz1 ligand Wnt1 after rat SCI improves motor functional recovery, increases myelin preservation and neuronal survival, and reduces early astroglial reactivity and NG2+ cell accumulation, highlighting the therapeutic potential of Wnt1 in this neuropathological situation.
Collapse
Affiliation(s)
- Pau González
- Laboratory of Molecular Neurology, Hospital Nacional de Parapléjicos, Toledo, Spain.
| | | | | | - Manuela Mollejo
- Department of Pathology, Hospital Virgen de La Salud, Toledo, Spain
| | | | - Alexander Marcillo
- Department of Pathology, University of Miami School of Medicine, Miami, USA
| | - Michael Norenberg
- Department of Pathology, University of Miami School of Medicine, Miami, USA
| | | |
Collapse
|
10
|
Identification of a circRNA-miRNA-mRNA network to explore the effects of circRNAs on pathogenesis and treatment of spinal cord injury. Life Sci 2020; 257:118039. [DOI: 10.1016/j.lfs.2020.118039] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 06/13/2020] [Accepted: 06/29/2020] [Indexed: 12/22/2022]
|
11
|
Xie AX, Madayag A, Minton SK, McCarthy KD, Malykhina AP. Sensory satellite glial Gq-GPCR activation alleviates inflammatory pain via peripheral adenosine 1 receptor activation. Sci Rep 2020; 10:14181. [PMID: 32843670 PMCID: PMC7447794 DOI: 10.1038/s41598-020-71073-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 08/10/2020] [Indexed: 02/07/2023] Open
Abstract
Glial fibrillary acidic protein expressing (GFAP+) glia modulate nociceptive neuronal activity in both the peripheral nervous system (PNS) and the central nervous system (CNS). Resident GFAP+ glia in dorsal root ganglia (DRG) known as satellite glial cells (SGCs) potentiate neuronal activity by releasing pro-inflammatory cytokines and neuroactive compounds. In this study, we tested the hypothesis that SGC Gq-coupled receptor (Gq-GPCR) signaling modulates pain sensitivity in vivo using Gfap-hM3Dq mice. Complete Freund's adjuvant (CFA) was used to induce inflammatory pain, and mechanical sensitivity and thermal sensitivity were used to assess the neuromodulatory effect of glial Gq-GPCR activation in awake mice. Pharmacogenetic activation of Gq-GPCR signaling in sensory SGCs decreased heat-induced nociceptive responses and reversed inflammation-induced mechanical allodynia via peripheral adenosine A1 receptor activation. These data reveal a previously unexplored role of sensory SGCs in decreasing afferent excitability. The identified molecular mechanism underlying the analgesic role of SGCs offers new approaches for reversing peripheral nociceptive sensitization.
Collapse
MESH Headings
- Animals
- Benzilates/pharmacology
- Clozapine/analogs & derivatives
- Clozapine/pharmacology
- Freund's Adjuvant/toxicity
- GTP-Binding Protein alpha Subunits, Gq-G11/physiology
- Genes, Synthetic
- Hot Temperature
- Hyperalgesia/physiopathology
- Hyperalgesia/prevention & control
- Inflammation/chemically induced
- Inflammation/physiopathology
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Muscarinic Agonists/pharmacology
- Neuroglia/enzymology
- Neuroglia/physiology
- Nociception/physiology
- Nortropanes/pharmacology
- Promoter Regions, Genetic
- Purinergic P1 Receptor Agonists/pharmacology
- Purinergic P1 Receptor Antagonists/pharmacology
- Receptor, Adenosine A1/drug effects
- Receptor, Adenosine A1/physiology
- Receptor, Muscarinic M3/drug effects
- Receptor, Muscarinic M3/genetics
- Receptor, Muscarinic M3/physiology
- Receptors, G-Protein-Coupled
- Recombinant Fusion Proteins/drug effects
- Recombinant Fusion Proteins/metabolism
- Theophylline/analogs & derivatives
- Theophylline/pharmacology
- Touch
- Xanthines/pharmacology
Collapse
Affiliation(s)
- Alison Xiaoqiao Xie
- Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill (UNC-CH), Chapel Hill, USA.
- Division of Urology, Department of Surgery, University of Colorado Denver (UCD), Anschutz Medical Campus (AMC), 12700E 19th Ave., Room 6440D, Mail stop C317, Aurora, CO, 80045, USA.
- Department of Surgery, UCD-AMC, Aurora, CO, USA.
| | - Aric Madayag
- Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill (UNC-CH), Chapel Hill, USA
- NeuroCycle Therapeutics, Inc., 3829 N Cramer St., Shorewood, WI, 53211, USA
| | - Suzanne K Minton
- Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill (UNC-CH), Chapel Hill, USA
- Certara, 5511 Capital Center Drive, Ste. 204, Raleigh, NC, 27606, USA
| | - Ken D McCarthy
- Professor Emeritus in the Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill, 120 Mason Farm Road, 4010 Genetic Medicine Bldg, Campus Box 7365, Chapel Hill, NC, 27599-7365, USA
| | - Anna P Malykhina
- Division of Urology, Department of Surgery, University of Colorado Denver (UCD), Anschutz Medical Campus (AMC), 12700E 19th Ave., Room 6440D, Mail stop C317, Aurora, CO, 80045, USA
- Department of Physiology and Biophysics, University of Colorado School of Medicine, 12700 East 19th Ave., Rm 6001, Mail Stop C317, Aurora, CO, 80045, USA
| |
Collapse
|
12
|
Götz S, Bribian A, López-Mascaraque L, Götz M, Grothe B, Kunz L. Heterogeneity of astrocytes: Electrophysiological properties of juxtavascular astrocytes before and after brain injury. Glia 2020; 69:346-361. [PMID: 32809228 DOI: 10.1002/glia.23900] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 07/20/2020] [Accepted: 07/30/2020] [Indexed: 12/31/2022]
Abstract
Astrocyte heterogeneity is increasingly recognized, but still little is known about juxtavascular astrocytes with their somata directly adjacent to blood vessels, despite their importance after brain injury. As juxtavascular astrocytes originate from common progenitor cells, that is, have a clonal origin, they may intrinsically differ from other, non-juxtavascular astrocytes. To explore this, we examined the electrophysiological properties of these groups of astrocytes and the underlying ion channels. Using brain slices of BAC Aldh1l1-eGFP transgenic mice with astrocytes labeled by GFP expression, we compared juxtavascular and non-juxtavascular astrocytes in the somatosensory cortex by means of whole-cell patch-clamp recordings and immunohistochemical staining. Prior to injury, juxta- and non-juxtavascular astrocytes exhibit comparable electrophysiological properties with characteristic mostly passive conductance and a typical negative resting membrane potential. Immunohistochemical analysis of K+ channels showed that all astrocytes were Kir 4.1+ , but revealed an intriguing difference for Kv 4.3. The expression of Kv 4.3 in sibling astrocytes (non-juxtavascular, juxtavascular and pial) was dependent on their ontogenetic origin with lowest levels in juxtavascular astrocytes located in upper cortical layers. After traumatic brain injury (TBI), we found profound changes in the electrophysiological type of astrocytes with a predominance of non-passive properties and this pattern was significantly enriched in juxtavascular astrocytes. This was accompanied by pronounced down-regulation of Kir 4.1 in proliferating astrocytes, which was significantly more in juxtavascular compared to non-juxtavascular astrocytes. Taken together, TBI induces profound differences in electrophysiological properties between juxtavascular and non-juxtavascular astrocytes that might be related to the preponderance of juxtavascular astrocyte proliferation.
Collapse
Affiliation(s)
- Stefanie Götz
- Division of Neurobiology, Department of Biology II, Ludwig-Maximilians-Universitaet (LMU) Munich, Martinsried, Germany.,Graduate School of Systemic Neurosciences, Ludwig-Maximilians-Universitaet (LMU) Munich, Martinsried, Germany.,Biomedical Center (BMC), Ludwig-Maximilians-Universitaet (LMU) Munich, SyNergy - Munich Cluster for Systems Neurology, Munich, Germany
| | - Ana Bribian
- Instituto Cajal-CSIC, Molecular, Cellular and Developmental Neurobiology Department, Madrid, Spain
| | - Laura López-Mascaraque
- Instituto Cajal-CSIC, Molecular, Cellular and Developmental Neurobiology Department, Madrid, Spain
| | - Magdalena Götz
- Biomedical Center (BMC), Ludwig-Maximilians-Universitaet (LMU) Munich, SyNergy - Munich Cluster for Systems Neurology, Munich, Germany.,Physiological Genomics, Biomedical Center (BMC), Ludwig-Maximilians-Universitaet (LMU) Munich, Martinsried, Germany.,Institute of Stem Cell Research, Helmholtz Center Munich, German Research Center for Environmental Health, Martinsried, Germany
| | - Benedikt Grothe
- Division of Neurobiology, Department of Biology II, Ludwig-Maximilians-Universitaet (LMU) Munich, Martinsried, Germany.,Biomedical Center (BMC), Ludwig-Maximilians-Universitaet (LMU) Munich, SyNergy - Munich Cluster for Systems Neurology, Munich, Germany
| | - Lars Kunz
- Division of Neurobiology, Department of Biology II, Ludwig-Maximilians-Universitaet (LMU) Munich, Martinsried, Germany
| |
Collapse
|
13
|
Boni JL, Kahanovitch U, Nwaobi SE, Floyd CL, Olsen ML. DNA methylation: A mechanism for sustained alteration of KIR4.1 expression following central nervous system insult. Glia 2020; 68:1495-1512. [PMID: 32068308 PMCID: PMC8665281 DOI: 10.1002/glia.23797] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 01/29/2020] [Accepted: 01/31/2020] [Indexed: 12/22/2022]
Abstract
Kir4.1, a glial-specific inwardly rectifying potassium channel, is implicated in astrocytic maintenance of K+ homeostasis. Underscoring the role of Kir4.1 in central nervous system (CNS) functioning, genetic mutations in KCNJ10, the gene which encodes Kir4.1, causes seizures, ataxia and developmental disability in humans. Kir4.1 protein and mRNA loss are consistently observed in CNS injury and neurological diseases linked to hyperexcitability and neuronal dysfunction, leading to the notion that Kir4.1 represents an attractive therapeutic target. Despite this, little is understood regarding the mechanisms that underpin this downregulation. Previous work by our lab revealed that DNA hypomethylation of the Kcnj10 gene functions to regulate mRNA levels during astrocyte maturation whereas hypermethylation in vitro led to decreased promoter activity. In the present study, we utilized two vastly different injury models with known acute and chronic loss of Kir4.1 protein and mRNA to evaluate the methylation status of Kcnj10 as a candidate molecular mechanism for reduced transcription and subsequent protein loss. Examining whole hippocampal tissue and isolated astrocytes, in a lithium-pilocarpine model of epilepsy, we consistently identified hypermethylation of CpG island two, which resides in the large intronic region spanning the Kcnj10 gene. Strikingly similar results were observed using the second injury paradigm, a fifth cervical (C5) vertebral hemi-contusion model of spinal cord injury. Our previous work indicates the same gene region is significantly hypomethylated when transcription increases during astrocyte maturation. Our results suggest that DNA methylation can bidirectionally modulate Kcnj10 transcription and may represent a targetable molecular mechanism for the restoring astroglial Kir4.1 expression following CNS insult.
Collapse
Affiliation(s)
- Jessica L Boni
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
- School of Neuroscience, Virginia Polytechnic and State University, Blacksburg, Virginia
| | - Uri Kahanovitch
- School of Neuroscience, Virginia Polytechnic and State University, Blacksburg, Virginia
| | - Sinifunanya E Nwaobi
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
- Division of Pediatric Neurology, UCLA Mattel Children's Hospital, University of California Los Angeles, Los Angeles, California
| | - Candace L Floyd
- Department of Physical Medicine and Rehabilitation, University of Alabama at Birmingham, Birmingham, Alabama
- Department of Physical Medicine and Rehabilitation, University of Utah Health, Salt Lake City, Utah
| | - Michelle L Olsen
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
- School of Neuroscience, Virginia Polytechnic and State University, Blacksburg, Virginia
| |
Collapse
|
14
|
Zuidema JM, Gilbert RJ, Gottipati MK. Biomaterial Approaches to Modulate Reactive Astroglial Response. Cells Tissues Organs 2018; 205:372-395. [PMID: 30517922 PMCID: PMC6397084 DOI: 10.1159/000494667] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 10/18/2018] [Indexed: 11/19/2022] Open
Abstract
Over several decades, biomaterial scientists have developed materials to spur axonal regeneration and limit secondary injury and tested these materials within preclinical animal models. Rarely, though, are astrocytes examined comprehensively when biomaterials are placed into the injury site. Astrocytes support neuronal function in the central nervous system. Following an injury, astrocytes undergo reactive gliosis and create a glial scar. The astrocytic glial scar forms a dense barrier which restricts the extension of regenerating axons through the injury site. However, there are several beneficial effects of the glial scar, including helping to reform the blood-brain barrier, limiting the extent of secondary injury, and supporting the health of regenerating axons near the injury site. This review provides a brief introduction to the role of astrocytes in the spinal cord, discusses astrocyte phenotypic changes that occur following injury, and highlights studies that explored astrocyte changes in response to biomaterials tested within in vitro or in vivo environments. Overall, we suggest that in order to improve biomaterial designs for spinal cord injury applications, investigators should more thoroughly consider the astrocyte response to such designs.
Collapse
Affiliation(s)
- Jonathan M Zuidema
- Department of Chemistry and Biochemistry, University of California, San Diego, California, USA
| | - Ryan J Gilbert
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, New York, USA
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York, USA
| | - Manoj K Gottipati
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, New York, USA,
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York, USA,
- Center for Brain and Spinal Cord Repair, Department of Neuroscience, The Ohio State University, Columbus, Ohio, USA,
| |
Collapse
|
15
|
Pallottie A, Ratnayake A, Ni L, Acioglu C, Li L, Mirabelli E, Heary RF, Elkabes S. A toll-like receptor 9 antagonist restores below-level glial glutamate transporter expression in the dorsal horn following spinal cord injury. Sci Rep 2018; 8:8723. [PMID: 29880832 PMCID: PMC5992189 DOI: 10.1038/s41598-018-26915-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 05/18/2018] [Indexed: 01/04/2023] Open
Abstract
Spinal cord (SC) trauma elicits pathological changes at the primary lesion and in regions distant from the injury epicenter. Therapeutic agents that target mechanisms at the injury site are likely to exert additional effects in these remote regions. We previously reported that a toll-like receptor 9 (TLR9) antagonist, oligodeoxynucleotide 2088 (ODN 2088), improves functional deficits and modulates the milieu at the epicenter in mice sustaining a mid-thoracic contusion. The present investigations use the same paradigm to assess ODN 2088-elicited alterations in the lumbar dorsal horn (LDH), a region remote from the injury site where SCI-induced molecular alterations have been well defined. We report that ODN 2088 counteracts the SCI-elicited decrease in glial glutamate aspartate transporter (GLAST) and glutamate transporter 1 (GLT1) levels, whereas the levels of the neuronal glutamate transporter excitatory amino acid carrier 1 (EAAC1) and astroglial GABA transporter 3 (GAT3) were unaffected. The restoration of GLAST and GLT1 was neither paralleled by a global effect on astrocyte and microglia activation nor by changes in the expression of cytokines and growth factors reported to regulate these transporters. We conclude that the effects of intrathecal ODN 2088 treatment extend to loci beyond the epicenter by selectively targeting glial glutamate transporters.
Collapse
Affiliation(s)
- Alexandra Pallottie
- The Reynolds Family Spine Laboratory, New Jersey Medical School, Department of Neurological Surgery, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA.,The School of Graduate Studies, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA
| | - Ayomi Ratnayake
- The Reynolds Family Spine Laboratory, New Jersey Medical School, Department of Neurological Surgery, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA
| | - Li Ni
- The Reynolds Family Spine Laboratory, New Jersey Medical School, Department of Neurological Surgery, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA
| | - Cigdem Acioglu
- The Reynolds Family Spine Laboratory, New Jersey Medical School, Department of Neurological Surgery, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA
| | - Lun Li
- The Reynolds Family Spine Laboratory, New Jersey Medical School, Department of Neurological Surgery, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA.,The School of Graduate Studies, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA
| | - Ersilia Mirabelli
- The Reynolds Family Spine Laboratory, New Jersey Medical School, Department of Neurological Surgery, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA.,The School of Graduate Studies, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA
| | - Robert F Heary
- The Reynolds Family Spine Laboratory, New Jersey Medical School, Department of Neurological Surgery, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA.,The School of Graduate Studies, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA
| | - Stella Elkabes
- The Reynolds Family Spine Laboratory, New Jersey Medical School, Department of Neurological Surgery, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA. .,The School of Graduate Studies, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA.
| |
Collapse
|
16
|
Nicola F, Marques MR, Odorcyk F, Petenuzzo L, Aristimunha D, Vizuete A, Sanches EF, Pereira DP, Maurmann N, Gonçalves CA, Pranke P, Netto CA. Stem Cells from Human Exfoliated Deciduous Teeth Modulate Early Astrocyte Response after Spinal Cord Contusion. Mol Neurobiol 2018; 56:748-760. [PMID: 29796991 DOI: 10.1007/s12035-018-1127-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Accepted: 05/11/2018] [Indexed: 12/19/2022]
Abstract
The transplantation of stem cells from human exfoliated deciduous teeth (SHED) has been studied as a possible treatment strategy for spinal cord injuries (SCIs) due to its potential for promoting tissue protection and functional recovery. The aim of the present study was to investigate the effects of the early transplantation of SHED on glial scar formation and astrocytic reaction after an experimental model of SCI. Wistar rats were spinalized using the NYU Impactor. Animals were randomly distributed into three groups: control (naive) (animal with no manipulation); SCI (receiving laminectomy followed by SCI and treated with vehicle), and SHED (SCI rat treated with intraspinal SHED transplantation, 1 h after SCI). In vitro investigation demonstrated that SHED were able to express mesenchymal stem cells, vimentin and S100B markers, related with neural progenitor and glial cells, respectively. The acute SHED transplantation promoted functional recovery, measured as from the first week after spinal cord contusion by Basso, Beattie, and Bresnahan scale. Twenty-four and 48 h after lesion, flow cytometry revealed a spinal cord vimentin+ cells increment in the SHED group. The increase of vimentin+ cells was confirmed by immunofluorescence. Moreover, the bioavailability of astrocytic proteins such as S100B and Kir4.1 shown to be increased in the spinal cord of SHED group, whereas there was a glial scar reduction, as indicated by ELISA and Western blot techniques. The presented results support that SHED act as a neuroprotector agent after transplantation, probably through paracrine signaling to reduce glial scar formation, inducing tissue plasticity and functional recovery.
Collapse
Affiliation(s)
- Fabrício Nicola
- Post Graduate Program in Neuroscience, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil. .,Department of Biochemistry, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, R. Ramiro Barcelos, 2600 anexo, Porto Alegre, Rio Grande do Sul, 90035-003, Brazil.
| | - Marília Rossato Marques
- Post Graduate Program in Neuroscience, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Department of Biochemistry, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, R. Ramiro Barcelos, 2600 anexo, Porto Alegre, Rio Grande do Sul, 90035-003, Brazil
| | - Felipe Odorcyk
- Post Graduate Program in Neuroscience, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Department of Biochemistry, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, R. Ramiro Barcelos, 2600 anexo, Porto Alegre, Rio Grande do Sul, 90035-003, Brazil
| | - Letícia Petenuzzo
- Department of Biochemistry, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, R. Ramiro Barcelos, 2600 anexo, Porto Alegre, Rio Grande do Sul, 90035-003, Brazil
| | - Dirceu Aristimunha
- Department of Biochemistry, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, R. Ramiro Barcelos, 2600 anexo, Porto Alegre, Rio Grande do Sul, 90035-003, Brazil
| | - Adriana Vizuete
- Department of Biochemistry, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, R. Ramiro Barcelos, 2600 anexo, Porto Alegre, Rio Grande do Sul, 90035-003, Brazil
| | - Eduardo Farias Sanches
- Department of Biochemistry, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, R. Ramiro Barcelos, 2600 anexo, Porto Alegre, Rio Grande do Sul, 90035-003, Brazil
| | - Daniela Pavulack Pereira
- Hematology and Stem Cell Laboratory, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Natasha Maurmann
- Hematology and Stem Cell Laboratory, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Post Graduate Program in Physiology, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Carlos-Alberto Gonçalves
- Department of Biochemistry, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, R. Ramiro Barcelos, 2600 anexo, Porto Alegre, Rio Grande do Sul, 90035-003, Brazil
| | - Patricia Pranke
- Hematology and Stem Cell Laboratory, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Post Graduate Program in Physiology, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Stem Cell Research Institute, Porto Alegre, Brazil
| | - Carlos Alexandre Netto
- Department of Biochemistry, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, R. Ramiro Barcelos, 2600 anexo, Porto Alegre, Rio Grande do Sul, 90035-003, Brazil
| |
Collapse
|
17
|
Kelley KW, Ben Haim L, Schirmer L, Tyzack GE, Tolman M, Miller JG, Tsai HH, Chang SM, Molofsky AV, Yang Y, Patani R, Lakatos A, Ullian EM, Rowitch DH. Kir4.1-Dependent Astrocyte-Fast Motor Neuron Interactions Are Required for Peak Strength. Neuron 2018; 98:306-319.e7. [PMID: 29606582 PMCID: PMC5919779 DOI: 10.1016/j.neuron.2018.03.010] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 11/08/2017] [Accepted: 03/05/2018] [Indexed: 12/11/2022]
Abstract
Diversified neurons are essential for sensorimotor function, but whether astrocytes become specialized to optimize circuit performance remains unclear. Large fast α-motor neurons (FαMNs) of spinal cord innervate fast-twitch muscles that generate peak strength. We report that ventral horn astrocytes express the inward-rectifying K+ channel Kir4.1 (a.k.a. Kcnj10) around MNs in a VGLUT1-dependent manner. Loss of astrocyte-encoded Kir4.1 selectively altered FαMN size and function and led to reduced peak strength. Overexpression of Kir4.1 in astrocytes was sufficient to increase MN size through activation of the PI3K/mTOR/pS6 pathway. Kir4.1 was downregulated cell autonomously in astrocytes derived from amyotrophic lateral sclerosis (ALS) patients with SOD1 mutation. However, astrocyte Kir4.1 was dispensable for FαMN survival even in the mutant SOD1 background. These findings show that astrocyte Kir4.1 is essential for maintenance of peak strength and suggest that Kir4.1 downregulation might uncouple symptoms of muscle weakness from MN cell death in diseases like ALS. Kir4.1 is upregulated in astrocytes around high-activity alpha motor neurons (MNs) Astrocyte Kir4.1 KO caused decreased peak strength without alpha MN loss ALS patient-derived astrocytes show cell-autonomous Kir4.1 downregulation Astrocyte Kir4.1 regulates MN size through PI3K/mTOR/pS6 activation
Collapse
Affiliation(s)
- Kevin W Kelley
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94143, USA; Departments of Pediatrics and Neurosurgery, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Lucile Ben Haim
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94143, USA; Departments of Pediatrics and Neurosurgery, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Lucas Schirmer
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94143, USA; Departments of Pediatrics and Neurosurgery, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Giulia E Tyzack
- Department of Molecular Neuroscience, Institute of Neurology, University College London, London WC1N 3BG, UK; The Francis Crick Institute, London NW1 1AT, UK
| | - Michaela Tolman
- Sackler School of Biomedical Sciences, Tufts University, Boston, MA 02111, USA
| | - John G Miller
- Department of Psychiatry, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Hui-Hsin Tsai
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94143, USA; Departments of Pediatrics and Neurosurgery, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Sandra M Chang
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94143, USA; Departments of Pediatrics and Neurosurgery, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Anna V Molofsky
- Department of Psychiatry, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Yongjie Yang
- Sackler School of Biomedical Sciences, Tufts University, Boston, MA 02111, USA
| | - Rickie Patani
- Department of Molecular Neuroscience, Institute of Neurology, University College London, London WC1N 3BG, UK; The Francis Crick Institute, London NW1 1AT, UK
| | - Andras Lakatos
- John van Geest Centre for Brain Repair and Department of Clinical Neurosciences, University of Cambridge, Cambridge CB20QQ, UK
| | - Erik M Ullian
- Department of Ophthalmology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - David H Rowitch
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94143, USA; Departments of Pediatrics and Neurosurgery, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Paediatrics and Wellcome Trust-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB20QQ, UK.
| |
Collapse
|
18
|
Post-injury administration of a combination of memantine and 17β-estradiol is protective in a rat model of traumatic brain injury. Neurochem Int 2017; 111:57-68. [DOI: 10.1016/j.neuint.2017.04.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Revised: 04/25/2017] [Accepted: 04/27/2017] [Indexed: 11/23/2022]
|
19
|
Ludwig PE, Patil AA, Chamczuk AJ, Agrawal DK. Hormonal therapy in traumatic spinal cord injury. Am J Transl Res 2017; 9:3881-3895. [PMID: 28979667 PMCID: PMC5622236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 08/25/2017] [Indexed: 06/07/2023]
Abstract
Traumatic spinal cord injuries are major health problems and the underlying pathophysiological events and treatment strategies are currently under investigation. In this article, we critically reviewed the literature investigating the effects of estrogen, progesterone, and human chorionic gonadotropin on spinal cord damage or preservation following traumatic spinal cord injury. The National Library of Medicine database was searched through December 2016 using PubMed for articles addressing the clinical relevance of the hormones to improve neural structural integrity following traumatic spinal cord injury. It was found that each of these hormones, through varied mechanisms, could serve to reduce the harmful effects associated with spinal cord injury, and could aid in restoring some function to the injured spinal cord in the animal models. The most striking effects were seen in the reduction of inflammation commonly linked to injury of the central nervous system. The effects of human chorionic gonadotropin administration following spinal cord injury have received far less attention than those of either estrogen or progesterone, and additional inquiry could be of general benefit. In this article, we discussed the outstanding questions and suggested future directions for further investigation.
Collapse
Affiliation(s)
- Parker E Ludwig
- Department of Clinical and Translational Science, Creighton University School of MedicineOmaha, NE, USA
| | - Arun A Patil
- Department of Clinical and Translational Science, Creighton University School of MedicineOmaha, NE, USA
- Department of Neurosurgery, Creighton University School of MedicineOmaha, NE, USA
| | - Andrea J Chamczuk
- Department of Neurosurgery, Creighton University School of MedicineOmaha, NE, USA
| | - Devendra K Agrawal
- Department of Clinical and Translational Science, Creighton University School of MedicineOmaha, NE, USA
| |
Collapse
|
20
|
Zendedel A, Mönnink F, Hassanzadeh G, Zaminy A, Ansar MM, Habib P, Slowik A, Kipp M, Beyer C. Estrogen Attenuates Local Inflammasome Expression and Activation after Spinal Cord Injury. Mol Neurobiol 2017; 55:1364-1375. [PMID: 28127698 DOI: 10.1007/s12035-017-0400-2] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 01/11/2017] [Indexed: 10/20/2022]
Abstract
17-estradiol (E2) is a neuroprotective hormone with a high anti-inflammatory potential in different neurological disorders. The inflammatory response initiated by spinal cord injury (SCI) involves the processing of interleukin-1beta (IL-1b) and IL-18 mediated by caspase-1 which is under the control of an intracellular multiprotein complex called inflammasome. We recently described in a SCI model that between 24 and 72 h post-injury, most of inflammasome components including IL-18, IL-1b, NLRP3, ASC, and caspase-1 are upregulated. In this study, we investigated the influence of E2 treatment after spinal cord contusion on inflammasome regulation. After contusion of T9 spinal segment, 12-week-old male Wistar rats were treated subcutaneously with E2 immediately after injury and every 12 h for the next 3 days. Behavioral scores were significantly improved in E2-treated animals compared to vehicle-treated groups. Functional improvement in E2-treated animals was paralleled by the attenuated expression of certain inflammasome components such as ASC, NLRP1b, and NLRP3 together with IL1b, IL-18, and caspase-1. On the histopathological level, microgliosis and oligodendrocyte injury was ameliorated. These findings support and extend the knowledge of the E2-mediated neuroprotective function during SCI. The control of the inflammasome machinery by E2 might be a missing piece of the puzzle to understand the anti-inflammatory potency of E2.
Collapse
Affiliation(s)
- Adib Zendedel
- Institute of Neuroanatomy, Faculty of Medicine, RWTH Aachen University, Wendlingweg 2, 52074, Aachen, Germany.,Giulan Neuroscience Research Center, Department of Anatomical Sciences, Faculty of Medicine, Guilan University of Medical Sciences, Rasht, Iran
| | - Fabian Mönnink
- Institute of Neuroanatomy, Faculty of Medicine, RWTH Aachen University, Wendlingweg 2, 52074, Aachen, Germany
| | - Gholamreza Hassanzadeh
- Department of Anatomy, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
| | - Arash Zaminy
- Giulan Neuroscience Research Center, Department of Anatomical Sciences, Faculty of Medicine, Guilan University of Medical Sciences, Rasht, Iran
| | - Malek Masoud Ansar
- Giulan Neuroscience Research Center, Department of Anatomical Sciences, Faculty of Medicine, Guilan University of Medical Sciences, Rasht, Iran
| | - Pardes Habib
- Department of Neurology, RWTH Aachen, 52074, Aachen, Germany
| | - Alexander Slowik
- Institute of Neuroanatomy, Faculty of Medicine, RWTH Aachen University, Wendlingweg 2, 52074, Aachen, Germany
| | - Markus Kipp
- Department of Anatomy II, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Cordian Beyer
- Institute of Neuroanatomy, Faculty of Medicine, RWTH Aachen University, Wendlingweg 2, 52074, Aachen, Germany.,JARA-Brain, 52074, Aachen, Germany
| |
Collapse
|
21
|
Miller SJ, Zhang PW, Glatzer J, Rothstein JD. Astroglial transcriptome dysregulation in early disease of an ALS mutant SOD1 mouse model. J Neurogenet 2016; 31:37-48. [DOI: 10.1080/01677063.2016.1260128] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Sean J. Miller
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- The Brain Science Institute, Johns Hopkins University, Baltimore, MD, USA
- Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Ping-wu Zhang
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- The Brain Science Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Jenna Glatzer
- The Brain Science Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Jeffrey D. Rothstein
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- The Brain Science Institute, Johns Hopkins University, Baltimore, MD, USA
- Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| |
Collapse
|
22
|
Seifert G, Henneberger C, Steinhäuser C. Diversity of astrocyte potassium channels: An update. Brain Res Bull 2016; 136:26-36. [PMID: 27965079 DOI: 10.1016/j.brainresbull.2016.12.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 12/08/2016] [Accepted: 12/09/2016] [Indexed: 01/08/2023]
Abstract
Astrocyte K+ channels and the K+ currents they mediate dwarf all other transmembrane conductances in these cells. This defining feature of astrocytes and its functional implications have been investigated intensely over the past decades. Nonetheless, many aspects of astrocyte K+ handling and signaling remain incompletely understood. In this review, we provide an update on the diversity of K+ channels expressed by astrocytes and new functional implications. We focus on inwardly-rectifying K+ channels (particularly Kir4.1), two-pore K+ channels and voltage and Ca2+-dependent K+ channels. We further discuss new insights into the involvement of these K+ channels in K+ buffering, control of synaptic transmission, regulation of the vasculature and in diseases of the central nervous system.
Collapse
Affiliation(s)
- Gerald Seifert
- Institute of Cellular Neurosciences, University of Bonn Medical School, Bonn, Germany.
| | - Christian Henneberger
- Institute of Cellular Neurosciences, University of Bonn Medical School, Bonn, Germany; German Center of Neurodegenerative Diseases (DZNE), Bonn, Germany; Institute of Neurology, University College London, London, United Kingdom
| | - Christian Steinhäuser
- Institute of Cellular Neurosciences, University of Bonn Medical School, Bonn, Germany.
| |
Collapse
|
23
|
Gu C. KIR4.1: K + Channel Illusion or Reality in the Autoimmune Pathogenesis of Multiple Sclerosis. Front Mol Neurosci 2016; 9:90. [PMID: 27729847 PMCID: PMC5037192 DOI: 10.3389/fnmol.2016.00090] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Accepted: 09/12/2016] [Indexed: 01/12/2023] Open
Abstract
Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS). Many believe autoimmune pathogenesis plays a key role in MS, but its target(s) remains elusive. A recent study detected autoantibodies against KIR4.1, an ATP-sensitive, inward rectifier potassium channel, in nearly half of the MS patients examined. KIR4.1 channels are expressed in astrocytes. Together with aquaporin 4 (AQP4) water channels, they regulate astrocytic functions vital for myelination. Autoantibodies against AQP4 have been established as a key biomarker for neuromyelitis optica (NMO) and contributed to diagnostic and treatment strategy adjustments. Similarly, identification of KIR4.1 autoantibodies could have high therapeutic values in treating MS. Consistent with its potential role in MS, KIR4.1 dysfunction is implicated in several neurological disorders. However, the enrichment of KIR4.1 autoantibodies in MS patients is questioned by follow-up studies. Further, investigations are needed to clarify this controversy and unravel the underlying mechanisms of MS pathogenesis.
Collapse
Affiliation(s)
- Chen Gu
- Department of Biological Chemistry and Pharmacology, The Ohio State University Columbus, OH, USA
| |
Collapse
|
24
|
Miller SJ, Rothstein JD. Astroglia in Thick Tissue with Super Resolution and Cellular Reconstruction. PLoS One 2016; 11:e0160391. [PMID: 27494718 PMCID: PMC4975496 DOI: 10.1371/journal.pone.0160391] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 07/18/2016] [Indexed: 01/24/2023] Open
Abstract
We utilized the recently published method of passive CLARITY to explore brain astrocytes for the first time with our optimized method. Astrocytes are the fundamental cells in the brain that act to maintain the synaptic activity of neurons, support metabolism of all neurons, and communicate through extensive networks throughout the CNS. They are the defining cell that differentiates lower organisms from humans. From a disease vantage point they are the principal cause of brain tumors and the propagator of neurodegenerative diseases like amyotrophic lateral sclerosis. New methods to study these cells is paramount. Our modified use of CLARITY provides a new way to study these brain cells. To reduce cost, speed up tissue clearing process, reduce human handling error, and to retrieve quantifiable data from single confocal and pseudo-super resolution microscopy we modified and optimized the original protocol.
Collapse
Affiliation(s)
- Sean J. Miller
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
- The Brain Science Institute at Johns Hopkins University, Baltimore, MD, United States of America
- Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Jeffrey D. Rothstein
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
- The Brain Science Institute at Johns Hopkins University, Baltimore, MD, United States of America
- Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
- * E-mail:
| |
Collapse
|
25
|
Abstract
Epilepsy is among the most prevalent chronic neurological diseases and affects an estimated 2.2 million people in the United States alone. About one third of patients are resistant to currently available antiepileptic drugs, which are exclusively targeting neuronal function. Yet, reactive astrocytes have emerged as potential contributors to neuronal hyperexcitability and seizures. Astrocytes react to any kind of CNS insult with a range of cellular adjustments to form a scar and protect uninjured brain regions. This process changes astrocyte physiology and can affect neuronal network function in various ways. Traumatic brain injury and stroke, both conditions that trigger astroglial scar formation, are leading causes of acquired epilepsies and surgical removal of this glial scar in patients with drug-resistant epilepsy can alleviate the seizures. This review will summarize the currently available evidence suggesting that epilepsy is not a disease of neurons alone, but that astrocytes, glial cells in the brain, can be major contributors to the disease, especially when they adopt a reactive state in response to central nervous system insult.
Collapse
Affiliation(s)
- Stefanie Robel
- Virginia Tech Carilion Research Institute, Roanoke, VA, USA
- Virginia Tech School of Neuroscience, Blacksburg, VA, USA
| |
Collapse
|
26
|
Nwaobi SE, Cuddapah VA, Patterson KC, Randolph AC, Olsen ML. The role of glial-specific Kir4.1 in normal and pathological states of the CNS. Acta Neuropathol 2016; 132:1-21. [PMID: 26961251 DOI: 10.1007/s00401-016-1553-1] [Citation(s) in RCA: 142] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 02/16/2016] [Accepted: 02/25/2016] [Indexed: 12/15/2022]
Abstract
Kir4.1 is an inwardly rectifying K(+) channel expressed exclusively in glial cells in the central nervous system. In glia, Kir4.1 is implicated in several functions including extracellular K(+) homeostasis, maintenance of astrocyte resting membrane potential, cell volume regulation, and facilitation of glutamate uptake. Knockout of Kir4.1 in rodent models leads to severe neurological deficits, including ataxia, seizures, sensorineural deafness, and early postnatal death. Accumulating evidence indicates that Kir4.1 plays an integral role in the central nervous system, prompting many laboratories to study the potential role that Kir4.1 plays in human disease. In this article, we review the growing evidence implicating Kir4.1 in a wide array of neurological disease. Recent literature suggests Kir4.1 dysfunction facilitates neuronal hyperexcitability and may contribute to epilepsy. Genetic screens demonstrate that mutations of KCNJ10, the gene encoding Kir4.1, causes SeSAME/EAST syndrome, which is characterized by early onset seizures, compromised verbal and motor skills, profound cognitive deficits, and salt-wasting. KCNJ10 has also been linked to developmental disorders including autism. Cerebral trauma, ischemia, and inflammation are all associated with decreased astrocytic Kir4.1 current amplitude and astrocytic dysfunction. Additionally, neurodegenerative diseases such as Alzheimer disease and amyotrophic lateral sclerosis demonstrate loss of Kir4.1. This is particularly exciting in the context of Huntington disease, another neurodegenerative disorder in which restoration of Kir4.1 ameliorated motor deficits, decreased medium spiny neuron hyperexcitability, and extended survival in mouse models. Understanding the expression and regulation of Kir4.1 will be critical in determining if this channel can be exploited for therapeutic benefit.
Collapse
|
27
|
Najafi E, Stoodley MA, Bilston LE, Hemley SJ. Inwardly rectifying potassium channel 4.1 expression in post-traumatic syringomyelia. Neuroscience 2016; 317:23-35. [PMID: 26768400 DOI: 10.1016/j.neuroscience.2016.01.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2015] [Revised: 12/23/2015] [Accepted: 01/02/2016] [Indexed: 10/22/2022]
Abstract
Post-traumatic syringomyelia (PTS) is a serious neurological disorder characterized by fluid filled cavities that develop in the spinal cord. PTS is thought to be caused by an imbalance between fluid inflow and outflow in the spinal cord, but the underlying mechanisms are unknown. The ion channel Kir4.1 plays an important role in the uptake of K(+) ions from the extracellular space and release of K(+) ions into the microvasculature, generating an osmotic gradient that drives water movement. Changes in Kir4.1 expression may contribute to disturbances in K(+) homeostasis and subsequently fluid imbalance. Here we investigated whether changes in Kir4.1 protein expression occur in PTS. Western blotting and immunohistochemistry were used to evaluate Kir4.1 and glial fibrillary acidic protein (GFAP) expression in a rodent model of PTS at 3 days, 1, 6 or 12 weeks post-surgery. In Western blotting experiments, Kir4.1 expression increased 1 week post-surgery at the level of the cavity. Immunohistochemical analysis examined changes in the spinal parenchyma directly in contact with the syrinx cavity. In these experiments, there was a significant decrease in Kir4.1 expression in PTS animals compared to controls at 3 days and 6 weeks post-surgery, while an up-regulation of GFAP in PTS animals was observed at 1 and 12 weeks. This suggests that while overall Kir4.1 expression is unchanged at these time-points, there are many astrocytes surrounding the syrinx cavity that are not expressing Kir4.1. The results demonstrate a disturbance in the removal of K(+) ions in tissue surrounding a post-traumatic syrinx cavity. It is possible this contributes to water accumulation in the injured spinal cord leading to syrinx formation or exacerbation of the underlying pathology.
Collapse
Affiliation(s)
- E Najafi
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia.
| | - M A Stoodley
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia.
| | - L E Bilston
- Neuroscience Research Australia, Sydney, NSW, Australia; Prince of Wales Clinical School, University of New South Wales, Randwick, NSW, Australia.
| | - S J Hemley
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia.
| |
Collapse
|
28
|
Weller J, Steinhäuser C, Seifert G. pH-Sensitive K+ Currents and Properties of K2P Channels in Murine Hippocampal Astrocytes. ION CHANNELS AS THERAPEUTIC TARGETS, PART A 2016; 103:263-94. [DOI: 10.1016/bs.apcsb.2015.10.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
|
29
|
Minkel HR, Anwer TZ, Arps KM, Brenner M, Olsen ML. Elevated GFAP induces astrocyte dysfunction in caudal brain regions: A potential mechanism for hindbrain involved symptoms in type II Alexander disease. Glia 2015; 63:2285-97. [PMID: 26190408 PMCID: PMC4555878 DOI: 10.1002/glia.22893] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 07/01/2015] [Indexed: 12/14/2022]
Abstract
Alexander Disease (AxD) is a "gliopathy" caused by toxic, dominant gain-of-function mutations in the glial fibrillary acidic protein (GFAP) gene. Two distinct types of AxD exist. Type I AxD affected individuals develop cerebral symptoms by 4 years of age and suffer from macrocephaly, seizures, and physical and mental delays. As detection and diagnosis have improved, approximately half of all AxD patients diagnosed have onset >4 years and brainstem/spinal cord involvement. Type II AxD patients experience ataxia, palatal myoclonus, dysphagia, and dysphonia. No study has examined a mechanistic link between the GFAP mutations and caudal symptoms present in type II AxD patients. We demonstrate that two key astrocytic functions, the ability to regulate extracellular glutamate and to take up K(+) via K+ channels, are compromised in hindbrain regions and spinal cord in AxD mice. Spinal cord astrocytes in AxD transgenic mice are depolarized relative to WT littermates, and have a three-fold reduction in Ba(2+) -sensitive Kir4.1 mediated currents and six-fold reduction in glutamate uptake currents. The loss of these two functions is due to significant decreases in Kir4.1 (>70%) and GLT-1 (>60%) protein expression. mRNA expression for KCNJ10 and SLC1A2, the genes that code for Kir4.1 and GLT-1, are significantly reduced by postnatal Day 7. Protein and mRNA reductions for Kir4.1 and GLT-1 are exacerbated in AxD models that demonstrate earlier accumulation of GFAP and increased Rosenthal fiber formation. These findings provide a mechanistic link between the GFAP mutations/overexpression and the symptoms in those affected with Type II AxD.
Collapse
Affiliation(s)
- Heather R Minkel
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
- Center for Glial Biology in Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Tooba Z Anwer
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
- Center for Glial Biology in Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Kara M Arps
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
- Center for Glial Biology in Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Michael Brenner
- Center for Glial Biology in Medicine, University of Alabama at Birmingham, Birmingham, Alabama
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Michelle L Olsen
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
- Center for Glial Biology in Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| |
Collapse
|
30
|
Falnikar A, Hala TJ, Poulsen DJ, Lepore AC. GLT1 overexpression reverses established neuropathic pain-related behavior and attenuates chronic dorsal horn neuron activation following cervical spinal cord injury. Glia 2015; 64:396-406. [PMID: 26496514 DOI: 10.1002/glia.22936] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 10/06/2015] [Indexed: 01/23/2023]
Abstract
Development of neuropathic pain occurs in a major portion of traumatic spinal cord injury (SCI) patients, resulting in debilitating and often long-term physical and psychological burdens. Following SCI, chronic dysregulation of extracellular glutamate homeostasis has been shown to play a key role in persistent central hyperexcitability of superficial dorsal horn neurons that mediate pain neurotransmission, leading to various forms of neuropathic pain. Astrocytes express the major CNS glutamate transporter, GLT1, which is responsible for the vast majority of functional glutamate uptake, particularly in the spinal cord. In our unilateral cervical contusion model of mouse SCI that is associated with ipsilateral forepaw heat hypersensitivity (a form of chronic at-level neuropathic pain-related behavior), we previously reported significant and long-lasting reductions in GLT1 expression and functional GLT1-mediated glutamate uptake in cervical spinal cord dorsal horn. To therapeutically address GLT1 dysfunction following cervical contusion SCI, we injected an adeno-associated virus type 8 (AAV8)-Gfa2 vector into the superficial dorsal horn to increase GLT1 expression selectively in astrocytes. Compared to both contusion-only animals and injured mice that received AAV8-eGFP control injection, AAV8-GLT1 delivery increased GLT1 protein expression in astrocytes of the injured cervical spinal cord dorsal horn, resulting in a significant and persistent reversal of already-established heat hypersensitivity. Furthermore, AAV8-GLT1 injection significantly reduced expression of the transcription factor and marker of persistently increased neuronal activation, ΔFosB, in superficial dorsal horn neurons. These results demonstrate that focal restoration of GLT1 expression in the superficial dorsal horn is a promising target for treating chronic neuropathic pain following SCI.
Collapse
Affiliation(s)
- Aditi Falnikar
- Department of Neuroscience, Farber Institute for Neurosciences, Sidney Kimmel Medical College at Thomas Jefferson University, 900 Walnut Street, JHN 469, Philadelphia, Pennsylvania
| | - Tamara J Hala
- Department of Neuroscience, Farber Institute for Neurosciences, Sidney Kimmel Medical College at Thomas Jefferson University, 900 Walnut Street, JHN 469, Philadelphia, Pennsylvania
| | - David J Poulsen
- Department of Neurosurgery, University at Buffalo, SUNY-School of Medicine and Biomedical Sciences, Buffalo, New York
| | - Angelo C Lepore
- Department of Neuroscience, Farber Institute for Neurosciences, Sidney Kimmel Medical College at Thomas Jefferson University, 900 Walnut Street, JHN 469, Philadelphia, Pennsylvania
| |
Collapse
|
31
|
Letaif OB, Cristante AF, de Barros Filho TEP, Ferreira R, dos Santos GB, da Rocha ID, Marcon RM. Effects of estrogen on functional and neurological recovery after spinal cord injury: An experimental study with rats. Clinics (Sao Paulo) 2015; 70:700-5. [PMID: 26598084 PMCID: PMC4602386 DOI: 10.6061/clinics/2015(10)08] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 07/23/2015] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVES To evaluate the functional and histological effects of estrogen as a neuroprotective agent after a standard experimentally induced spinal cord lesion. METHODS In this experimental study, 20 male Wistar rats were divided into two groups: one group with rats undergoing spinal cord injury (SCI) at T10 and receiving estrogen therapy with 17-beta estradiol (4mg/kg) immediately following the injury and after the placement of skin sutures and a control group with rats only subjected to SCI. A moderate standard experimentally induced SCI was produced using a computerized device that dropped a weight on the rat's spine from a height of 12.5 mm. Functional recovery was verified with the Basso, Beattie and Bresnahan scale on the 2nd, 7th, 14th, 21st, 28th, 35th and 42nd days after injury and by quantifying the motor-evoked potential on the 42nd day after injury. Histopathological evaluation of the SCI area was performed after euthanasia on the 42nd day. RESULTS The experimental group showed a significantly greater functional improvement from the 28th to the 42nd day of observation compared to the control group. The experimental group showed statistically significant improvements in the motor-evoked potential compared with the control group. The results of pathological histomorphometry evaluations showed a better neurological recovery in the experimental group, with respect to the proportion and diameter of the quantified nerve fibers. CONCLUSIONS Estrogen administration provided benefits in neurological and functional motor recovery in rats with SCI beginning at the 28th day after injury.
Collapse
Affiliation(s)
- Olavo Biraghi Letaif
- Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo Instituto de Ortopedia e Traumatologia, (IOT-HCFMUSP), Divisão de Cirurgia de Coluna Vertebral, Laboratório de Investigação Médica, São Paulo/SP, Brazil
- Corresponding author: E-mail:
| | - Alexandre Fogaça Cristante
- Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo Instituto de Ortopedia e Traumatologia, (IOT-HCFMUSP), Divisão de Cirurgia de Coluna Vertebral, Laboratório de Investigação Médica, São Paulo/SP, Brazil
| | - Tarcísio Eloy Pessoa de Barros Filho
- Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo Instituto de Ortopedia e Traumatologia, (IOT-HCFMUSP), Divisão de Cirurgia de Coluna Vertebral, Laboratório de Investigação Médica, São Paulo/SP, Brazil
| | - Ricardo Ferreira
- Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Instituto de Ortopedia e Traumatologia, (IOT-HCFMUSP), Laboratório de Investigação Médica (LIM-41), São Paulo, SP, Brazil
| | - Gustavo Bispo dos Santos
- Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo Instituto de Ortopedia e Traumatologia, (IOT-HCFMUSP), Divisão de Cirurgia de Coluna Vertebral, Laboratório de Investigação Médica, São Paulo/SP, Brazil
| | - Ivan Dias da Rocha
- Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo Instituto de Ortopedia e Traumatologia, (IOT-HCFMUSP), Divisão de Cirurgia de Coluna Vertebral, Laboratório de Investigação Médica, São Paulo/SP, Brazil
| | - Raphael Martus Marcon
- Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo Instituto de Ortopedia e Traumatologia, (IOT-HCFMUSP), Divisão de Cirurgia de Coluna Vertebral, Laboratório de Investigação Médica, São Paulo/SP, Brazil
| |
Collapse
|
32
|
Nwaobi SE, Olsen ML. Correlating Gene-specific DNA Methylation Changes with Expression and Transcriptional Activity of Astrocytic KCNJ10 (Kir4.1). J Vis Exp 2015. [PMID: 26436772 DOI: 10.3791/52406] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
DNA methylation serves to regulate gene expression through the covalent attachment of a methyl group onto the C5 position of a cytosine in a cytosine-guanine dinucleotide. While DNA methylation provides long-lasting and stable changes in gene expression, patterns and levels of DNA methylation are also subject to change based on a variety of signals and stimuli. As such, DNA methylation functions as a powerful and dynamic regulator of gene expression. The study of neuroepigenetics has revealed a variety of physiological and pathological states that are associated with both global and gene-specific changes in DNA methylation. Specifically, striking correlations between changes in gene expression and DNA methylation exist in neuropsychiatric and neurodegenerative disorders, during synaptic plasticity, and following CNS injury. However, as the field of neuroepigenetics continues to expand its understanding of the role of DNA methylation in CNS physiology, delineating causal relationships in regards to changes in gene expression and DNA methylation are essential. Moreover, in regards to the larger field of neuroscience, the presence of vast region and cell-specific differences requires techniques that address these variances when studying the transcriptome, proteome, and epigenome. Here we describe FACS sorting of cortical astrocytes that allows for subsequent examination of a both RNA transcription and DNA methylation. Furthermore, we detail a technique to examine DNA methylation, methylation sensitive high resolution melt analysis (MS-HRMA) as well as a luciferase promoter assay. Through the use of these combined techniques one is able to not only explore correlative changes between DNA methylation and gene expression, but also directly assess if changes in the DNA methylation status of a given gene region are sufficient to affect transcriptional activity.
Collapse
Affiliation(s)
- Sinifunanya E Nwaobi
- Department of Cell Developmental and Integrative Biology, University of Alabama at Birmingham
| | - Michelle L Olsen
- Department of Cell Developmental and Integrative Biology, University of Alabama at Birmingham;
| |
Collapse
|
33
|
Li K, Javed E, Scura D, Hala TJ, Seetharam S, Falnikar A, Richard JP, Chorath A, Maragakis NJ, Wright MC, Lepore AC. Human iPS cell-derived astrocyte transplants preserve respiratory function after spinal cord injury. Exp Neurol 2015. [PMID: 26216662 DOI: 10.1016/j.expneurol.2015.07.020] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Transplantation-based replacement of lost and/or dysfunctional astrocytes is a promising therapy for spinal cord injury (SCI) that has not been extensively explored, despite the integral roles played by astrocytes in the central nervous system (CNS). Induced pluripotent stem (iPS) cells are a clinically-relevant source of pluripotent cells that both avoid ethical issues of embryonic stem cells and allow for homogeneous derivation of mature cell types in large quantities, potentially in an autologous fashion. Despite their promise, the iPS cell field is in its infancy with respect to evaluating in vivo graft integration and therapeutic efficacy in SCI models. Astrocytes express the major glutamate transporter, GLT1, which is responsible for the vast majority of glutamate uptake in spinal cord. Following SCI, compromised GLT1 expression/function can increase susceptibility to excitotoxicity. We therefore evaluated intraspinal transplantation of human iPS cell-derived astrocytes (hIPSAs) following cervical contusion SCI as a novel strategy for reconstituting GLT1 expression and for protecting diaphragmatic respiratory neural circuitry. Transplant-derived cells showed robust long-term survival post-injection and efficiently differentiated into astrocytes in injured spinal cord of both immunesuppressed mice and rats. However, the majority of transplant-derived astrocytes did not express high levels of GLT1, particularly at early times post-injection. To enhance their ability to modulate extracellular glutamate levels, we engineered hIPSAs with lentivirus to constitutively express GLT1. Overexpression significantly increased GLT1 protein and functional GLT1-mediated glutamate uptake levels in hIPSAs both in vitro and in vivo post-transplantation. Compared to human fibroblast control and unmodified hIPSA transplantation, GLT1-overexpressing hIPSAs reduced (1) lesion size within the injured cervical spinal cord, (2) morphological denervation by respiratory phrenic motor neurons at the diaphragm neuromuscular junction, and (3) functional diaphragm denervation as measured by recording of spontaneous EMGs and evoked compound muscle action potentials. Our findings demonstrate that hiPSA transplantation is a therapeutically-powerful approach for SCI.
Collapse
Affiliation(s)
- Ke Li
- Department of Neuroscience, Farber Institute for Neurosciences, Sidney Kimmel Medical College at Thomas Jefferson University, 900 Walnut Street, JHN 469, Philadelphia, PA 19107, United States.
| | - Elham Javed
- Department of Neuroscience, Farber Institute for Neurosciences, Sidney Kimmel Medical College at Thomas Jefferson University, 900 Walnut Street, JHN 469, Philadelphia, PA 19107, United States.
| | - Daniel Scura
- Department of Neuroscience, Farber Institute for Neurosciences, Sidney Kimmel Medical College at Thomas Jefferson University, 900 Walnut Street, JHN 469, Philadelphia, PA 19107, United States.
| | - Tamara J Hala
- Department of Neuroscience, Farber Institute for Neurosciences, Sidney Kimmel Medical College at Thomas Jefferson University, 900 Walnut Street, JHN 469, Philadelphia, PA 19107, United States.
| | - Suneil Seetharam
- Department of Neuroscience, Farber Institute for Neurosciences, Sidney Kimmel Medical College at Thomas Jefferson University, 900 Walnut Street, JHN 469, Philadelphia, PA 19107, United States.
| | - Aditi Falnikar
- Department of Neuroscience, Farber Institute for Neurosciences, Sidney Kimmel Medical College at Thomas Jefferson University, 900 Walnut Street, JHN 469, Philadelphia, PA 19107, United States.
| | - Jean-Philippe Richard
- Department of Neurology, Johns Hopkins University School of Medicine, 855N. Wolfe St., Rangos 250, Baltimore, MD 21205, United States.
| | - Ashley Chorath
- Department of Neuroscience, Farber Institute for Neurosciences, Sidney Kimmel Medical College at Thomas Jefferson University, 900 Walnut Street, JHN 469, Philadelphia, PA 19107, United States.
| | - Nicholas J Maragakis
- Department of Neurology, Johns Hopkins University School of Medicine, 855N. Wolfe St., Rangos 250, Baltimore, MD 21205, United States.
| | - Megan C Wright
- Department of Biology, Arcadia University, 450S. Easton Rd., 220 Boyer Hall, Glenside, PA 19038, United States.
| | - Angelo C Lepore
- Department of Neuroscience, Farber Institute for Neurosciences, Sidney Kimmel Medical College at Thomas Jefferson University, 900 Walnut Street, JHN 469, Philadelphia, PA 19107, United States.
| |
Collapse
|
34
|
Cox A, Varma A, Banik N. Recent advances in the pharmacologic treatment of spinal cord injury. Metab Brain Dis 2015; 30:473-82. [PMID: 24833553 PMCID: PMC4233197 DOI: 10.1007/s11011-014-9547-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Accepted: 04/10/2014] [Indexed: 12/16/2022]
Abstract
A need exists for the effective treatment of individuals suffering from spinal cord injury (SCI). Recent advances in the understanding of the pathophysiological mechanisms occurring in SCI have resulted in an expansion of new therapeutic targets. This review summarizes both preclinical and clinical findings investigating the mechanisms and cognate pharmacologic therapeutics targeted to modulate hypoxia, ischemia, excitotoxicity, inflammation, apoptosis, epigenetic alterations, myelin regeneration and scar remodeling. Successful modulation of these targets has been demonstrated in both preclinical and clinical studies with agents such as Oxycyte, Minocycline, Riluzole, Premarin, Cethrin, and ATI-355. The translation of these agents into clinical studies highlights the progress the field has made in the past decade. SCI proves to be a complex condition; the numerous pathophysiological mechanisms occurring at varying time points suggests that a single agent approach to the treatment of SCI may not be optimal. As the field continues to mature, the hope is that the knowledge gained from these studies will be applied to the development of an effective multi-pronged treatment strategy for SCI.
Collapse
Affiliation(s)
- April Cox
- Department of Neurosciences, Medical University of South Carolina, 96 Jonathan Lucas ST. MSC606, Charleston, SC, 29425, USA,
| | | | | |
Collapse
|
35
|
Jukkola P, Gu C. Regulation of neurovascular coupling in autoimmunity to water and ion channels. Autoimmun Rev 2015; 14:258-67. [PMID: 25462580 PMCID: PMC4303502 DOI: 10.1016/j.autrev.2014.11.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Accepted: 11/15/2014] [Indexed: 12/27/2022]
Abstract
Much progress has been made in understanding autoimmune channelopathies, but the underlying pathogenic mechanisms are not always clear due to broad expression of some channel proteins. Recent studies show that autoimmune conditions that interfere with neurovascular coupling in the central nervous system (CNS) can lead to neurodegeneration. Cerebral blood flow that meets neuronal activity and metabolic demand is tightly regulated by local neural activity. This process of reciprocal regulation involves coordinated actions of a number of cell types, including neurons, glia, and vascular cells. In particular, astrocytic endfeet cover more than 90% of brain capillaries to assist blood-brain barrier (BBB) function, and wrap around synapses and nodes of Ranvier to communicate with neuronal activity. In this review, we highlight four types of channel proteins that are expressed in astrocytes, regarding their structures, biophysical properties, expression and distribution patterns, and related diseases including autoimmune disorders. Water channel aquaporin 4 (AQP4) and inwardly rectifying potassium (Kir4.1) channels are concentrated in astrocytic endfeet, whereas some voltage-gated Ca(2+) and two-pore domain K(+) channels are expressed throughout the cell body of reactive astrocytes. More channel proteins are found in astrocytes under normal and abnormal conditions. This research field will contribute to a better understanding of pathogenic mechanisms underlying autoimmune disorders.
Collapse
Affiliation(s)
- Peter Jukkola
- Biomedical Sciences Graduate Program, The Ohio State University, Columbus, OH 43210, USA
| | - Chen Gu
- Biomedical Sciences Graduate Program, The Ohio State University, Columbus, OH 43210, USA; Department of Neuroscience, The Ohio State University, Columbus, OH 43210, USA.
| |
Collapse
|
36
|
Heiman A, Pallottie A, Heary RF, Elkabes S. Toll-like receptors in central nervous system injury and disease: a focus on the spinal cord. Brain Behav Immun 2014; 42:232-45. [PMID: 25063708 DOI: 10.1016/j.bbi.2014.06.203] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Revised: 06/17/2014] [Accepted: 06/28/2014] [Indexed: 12/12/2022] Open
Abstract
Toll-like receptors (TLRs) are best known for recognizing pathogens and initiating an innate immune response to protect the host. However, they also detect tissue damage and induce sterile inflammation upon the binding of endogenous ligands released by stressed or injured cells. In addition to immune system-related cells, TLRs have been identified in central nervous system (CNS) neurons and glial subtypes including microglia, astrocytes and oligodendrocytes. Direct and indirect effects of TLR ligands on neurons and glial subtypes have been documented in vitro. Likewise, the effects of TLR ligands have been demonstrated in vivo using animal models of CNS trauma and disease including spinal cord injury (SCI), amyotrophic lateral sclerosis (ALS) and neuropathic pain. The indirect effects are most likely mediated via microglia or immune system cells that infiltrate the diseased or injured CNS. Despite considerable progress over the past decade, the role of TLRs in the physiological and pathological function of the spinal cord remains inadequately defined. Published reports collectively highlight TLRs as promising targets for therapeutic interventions in spinal cord pathology. The findings also underscore the complexity of TLR-mediated mechanisms and the necessity for further research in this field. The goals of the current review are to recapitulate the studies that investigated the role of TLRs in the spinal cord, to discuss potential future research directions, and to examine some of the challenges associated with pre-clinical studies pertinent to TLRs in the injured or diseased spinal cord.
Collapse
Affiliation(s)
- Adee Heiman
- Reynolds Family Spine Laboratory, Department of Neurological Surgery, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, United States
| | - Alexandra Pallottie
- Reynolds Family Spine Laboratory, Department of Neurological Surgery, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, United States; Graduate School of Biomedical Sciences, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, United States
| | - Robert F Heary
- Reynolds Family Spine Laboratory, Department of Neurological Surgery, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, United States
| | - Stella Elkabes
- Reynolds Family Spine Laboratory, Department of Neurological Surgery, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, United States.
| |
Collapse
|
37
|
Obara-Michlewska M, Ruszkiewicz J, Zielińska M, Verkhratsky A, Albrecht J. Astroglial NMDA receptors inhibit expression of Kir4.1 channels in glutamate-overexposed astrocytes in vitro and in the brain of rats with acute liver failure. Neurochem Int 2014; 88:20-5. [PMID: 25451797 DOI: 10.1016/j.neuint.2014.10.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Revised: 10/10/2014] [Accepted: 10/20/2014] [Indexed: 10/24/2022]
Abstract
Astroglial inward rectifying Kir4.1 potassium channels are fundamental for the maintenance of ion and water homeostasis in the central nervous system (CNS). Down-regulation of Kir4.1 expression is observed in CNS disorders associated with excessive extracellular glutamate (Glu) accumulation, including hepatic encephalopathy related to acute liver failure (ALF). Here we demonstrate that prolonged (3 days) treatment of cultured rat cortical astrocytes with 2 mM Glu or 100 µM NMDA decreases the expression of Kir4.1 mRNA and protein. Inhibition by Glu of Kir4.1 mRNA expression was reversed by NMDA receptor antagonists MK-801 and AP-5 (each at 50 µM), and by a non-transportable inhibitor of Glu uptake TBOA (100 µM). MK-801 reversed the inhibitory effect of Glu on Kir4.1 protein expression. In contrast, transcription of Kir4.1 channels was not affected by: (i) a transportable Glu uptake inhibitor PDC (100 µM); (ii) by group I mGluR antagonist MTEP (100 µM); (iii) by antagonists of oxidative-nitrosative stress (ONS) in astrocytes, including the neuroprotective amino acid taurine (Tau; 10 mM), the NADPH oxidase inhibitor apocyanine (APO; 300 µM), the nitric oxide synthase inhibitor, L-NNA (100 µM), and a membrane permeable glutathione precursor, glutathione-diethyl ester (GEE; 3 mM). Down-regulation of Kir4.1 transcription in rats with ALF was attenuated by intraperitoneal administration of a competitive NMDA receptor antagonist memantine, but not by histidine, which reverses ONS associated with ALF. Collectively, the results indicate that over-activation of astroglial NMDA receptors, aided by as yet undefined effects of Glu entry to astrocytes, is a primary cause of the reduction of Kir4.1 expression in CNS disorders associated with increased exposure to Glu.
Collapse
Affiliation(s)
- Marta Obara-Michlewska
- Department of Neurotoxicology, Mossakowski Medical Research Centre, Polish Academy of Science, Warsaw, Poland
| | - Joanna Ruszkiewicz
- Department of Neurotoxicology, Mossakowski Medical Research Centre, Polish Academy of Science, Warsaw, Poland
| | - Magdalena Zielińska
- Department of Neurotoxicology, Mossakowski Medical Research Centre, Polish Academy of Science, Warsaw, Poland
| | - Alexei Verkhratsky
- Department of Neurotoxicology, Mossakowski Medical Research Centre, Polish Academy of Science, Warsaw, Poland; Faculty of Life Sciences, University of Manchester, Manchester, UK
| | - Jan Albrecht
- Department of Neurotoxicology, Mossakowski Medical Research Centre, Polish Academy of Science, Warsaw, Poland.
| |
Collapse
|
38
|
Watson JL, Hala TJ, Putatunda R, Sannie D, Lepore AC. Persistent at-level thermal hyperalgesia and tactile allodynia accompany chronic neuronal and astrocyte activation in superficial dorsal horn following mouse cervical contusion spinal cord injury. PLoS One 2014; 9:e109099. [PMID: 25268642 PMCID: PMC4182513 DOI: 10.1371/journal.pone.0109099] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Accepted: 09/09/2014] [Indexed: 11/19/2022] Open
Abstract
In humans, sensory abnormalities, including neuropathic pain, often result from traumatic spinal cord injury (SCI). SCI can induce cellular changes in the CNS, termed central sensitization, that alter excitability of spinal cord neurons, including those in the dorsal horn involved in pain transmission. Persistently elevated levels of neuronal activity, glial activation, and glutamatergic transmission are thought to contribute to the hyperexcitability of these dorsal horn neurons, which can lead to maladaptive circuitry, aberrant pain processing and, ultimately, chronic neuropathic pain. Here we present a mouse model of SCI-induced neuropathic pain that exhibits a persistent pain phenotype accompanied by chronic neuronal hyperexcitability and glial activation in the spinal cord dorsal horn. We generated a unilateral cervical contusion injury at the C5 or C6 level of the adult mouse spinal cord. Following injury, an increase in the number of neurons expressing ΔFosB (a marker of chronic neuronal activation), persistent astrocyte activation and proliferation (as measured by GFAP and Ki67 expression), and a decrease in the expression of the astrocyte glutamate transporter GLT1 are observed in the ipsilateral superficial dorsal horn of cervical spinal cord. These changes have previously been associated with neuronal hyperexcitability and may contribute to altered pain transmission and chronic neuropathic pain. In our model, they are accompanied by robust at-level hyperaglesia in the ipsilateral forepaw and allodynia in both forepaws that are evident within two weeks following injury and persist for at least six weeks. Furthermore, the pain phenotype occurs in the absence of alterations in forelimb grip strength, suggesting that it represents sensory and not motor abnormalities. Given the importance of transgenic mouse technology, this clinically-relevant model provides a resource that can be used to study the molecular mechanisms contributing to neuropathic pain following SCI and to identify potential therapeutic targets for the treatment of chronic pathological pain.
Collapse
Affiliation(s)
- Jaime L. Watson
- Department of Neuroscience, Farber Institute for Neurosciences, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Tamara J. Hala
- Department of Neuroscience, Farber Institute for Neurosciences, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Rajarshi Putatunda
- Department of Neuroscience, Farber Institute for Neurosciences, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Daniel Sannie
- Department of Neuroscience, Farber Institute for Neurosciences, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Angelo C. Lepore
- Department of Neuroscience, Farber Institute for Neurosciences, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| |
Collapse
|
39
|
Naderi A, Asgari AR, Zahed R, Ghanbari A, Samandari R, Jorjani M. Estradiol attenuates spinal cord injury-related central pain by decreasing glutamate levels in thalamic VPL nucleus in male rats. Metab Brain Dis 2014; 29:763-70. [PMID: 24879046 DOI: 10.1007/s11011-014-9570-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 05/20/2014] [Indexed: 12/13/2022]
Abstract
Central neuropathic pain (CNP) is a complicated medical problem that involves both the spinal and supraspinal regions of the central nervous system. Estrogen, a neuroprotective agent, has been considered a possible candidate for CNP treatment. In this study, we examined the effects of a single dose of 17β-estradiol on glutamate levels in the ventral posterolateral (VPL) nucleus of the rat thalamus. Furthermore, we determined whether there was a correlation between glutamate levels and neuropathic pain induced by unilateral electrolytic spinothalamic tract (STT) lesion. STT lesioning was performed in male Wistar rats at the T8-T9 vertebrae; rats were then administered 17β-estradiol (4 mg/kg, i.p.) 30 min after injury. Glutamate samples were collected using a microdialysis probe and quantified by high performance liquid chromatography. Mechanical allodynia (MA) and thermal hyperalgesia (TH) thresholds were measured pre-injury and 7, 14, and 28 days post-injury. We found that STT lesion significantly increased glutamate levels in the ipsilateral VPL nucleus 14 and 28 days post-injury; this was accompanied by allodynia and hyperalgesia in the hind paws of the rats. Administering 17β-estradiol to the rats decreased glutamate levels in the ipsilateral VPL nucleus and significantly increased MA and TH thresholds. These results suggest that glutamate in the VPL nucleus of the thalamus is involved in the pathology of neuropathic pain after STT injury; furthermore, 17β-estradiol may attenuate this neuropathic pain by decreasing glutamate levels.
Collapse
Affiliation(s)
- Asieh Naderi
- Department of Physiology & Biophysics, Faculty of Medicine, Baqiyatallah University of Medical Sciences, Tehran, Iran,
| | | | | | | | | | | |
Collapse
|
40
|
Overexpression of the astrocyte glutamate transporter GLT1 exacerbates phrenic motor neuron degeneration, diaphragm compromise, and forelimb motor dysfunction following cervical contusion spinal cord injury. J Neurosci 2014; 34:7622-38. [PMID: 24872566 DOI: 10.1523/jneurosci.4690-13.2014] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
A major portion of spinal cord injury (SCI) cases affect midcervical levels, the location of the phrenic motor neuron (PhMN) pool that innervates the diaphragm. While initial trauma is uncontrollable, a valuable opportunity exists in the hours to days following SCI for preventing PhMN loss and consequent respiratory dysfunction that occurs during secondary degeneration. One of the primary causes of secondary injury is excitotoxic cell death due to dysregulation of extracellular glutamate homeostasis. GLT1, mainly expressed by astrocytes, is responsible for the vast majority of functional uptake of extracellular glutamate in the CNS, particularly in spinal cord. We found that, in bacterial artificial chromosome-GLT1-enhanced green fluorescent protein reporter mice following unilateral midcervical (C4) contusion SCI, numbers of GLT1-expressing astrocytes in ventral horn and total intraspinal GLT1 protein expression were reduced soon after injury and the decrease persisted for ≥6 weeks. We used intraspinal delivery of adeno-associated virus type 8 (AAV8)-Gfa2 vector to rat cervical spinal cord ventral horn for targeting focal astrocyte GLT1 overexpression in areas of PhMN loss. Intraspinal delivery of AAV8-Gfa2-GLT1 resulted in transduction primarily of GFAP(+) astrocytes that persisted for ≥6 weeks postinjury, as well as increased intraspinal GLT1 protein expression. Surprisingly, we found that astrocyte-targeted GLT1 overexpression increased lesion size, PhMN loss, phrenic nerve axonal degeneration, and diaphragm neuromuscular junction denervation, and resulted in reduced functional diaphragm innervation as assessed by phrenic nerve-diaphragm compound muscle action potential recordings. These results demonstrate that GLT1 overexpression via intraspinal AAV-Gfa2-GLT1 delivery exacerbates neuronal damage and increases respiratory impairment following cervical SCI.
Collapse
|
41
|
Liu Y, Sun Q, Chen X, Jing L, Wang W, Yu Z, Zhang G, Xie M. Linolenic acid provides multi-cellular protective effects after photothrombotic cerebral ischemia in rats. Neurochem Res 2014; 39:1797-808. [PMID: 25062759 DOI: 10.1007/s11064-014-1390-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 07/02/2014] [Accepted: 07/15/2014] [Indexed: 10/25/2022]
Abstract
Alpha-linolenic acid (LIN) has been shown to provide neuroprotective effects against cerebral ischemia. LIN is a potent activator of TREK-1 channel and LIN-induced neuroprotection disappears in Trek1-/- mice, suggesting that this channel is directly related to the LIN-induced resistance of brain against ischemia. However, the cellular mechanism underlying LIN induced neuroprotective effects after ischemia remains unclear. In this study, using a rat photochemical brain ischemia model, we investigated the effects of LIN on the protein abundance of astrocytic glutamate transporter and AQP4, microglia activation, cell apoptosis and behavioral recovery following ischemia. Administration of LIN rescued the protein abundance of astrocytic glutamate transporter GLT-1, decreased the protein abundance of AQP4 and brain edema, inhibited microglia activation, attenuated cell apoptosis and improved behavioral function recovery. Meanwhile, TREK-1 was widely distributed in the cortex and hippocampus, primarily localized in astrocytes and neurons. LIN could potentiate the TREK-1 mediated astrocytic passive conductance and hyperpolarize the membrane potential. Our results suggest that LIN provides multiple cellular neuroprotective effects in cerebral ischemia. TREK-1 may serve as a promising multi-mechanism therapeutic target for the treatment of stroke.
Collapse
Affiliation(s)
- Yang Liu
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China
| | | | | | | | | | | | | | | |
Collapse
|
42
|
Schirmer L, Srivastava R, Kalluri SR, Böttinger S, Herwerth M, Carassiti D, Srivastava B, Gempt J, Schlegel J, Kuhlmann T, Korn T, Reynolds R, Hemmer B. Differential loss of KIR4.1 immunoreactivity in multiple sclerosis lesions. Ann Neurol 2014; 75:810-28. [DOI: 10.1002/ana.24168] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Revised: 04/26/2014] [Accepted: 04/26/2014] [Indexed: 12/22/2022]
Affiliation(s)
- Lucas Schirmer
- Department of Neurology; Klinikum rechts der Isar, Technische Universität München; Munich Germany
| | - Rajneesh Srivastava
- Department of Neurology; Klinikum rechts der Isar, Technische Universität München; Munich Germany
| | - Sudhakar Reddy Kalluri
- Department of Neurology; Klinikum rechts der Isar, Technische Universität München; Munich Germany
| | - Susanne Böttinger
- Department of Neurology; Klinikum rechts der Isar, Technische Universität München; Munich Germany
| | - Marina Herwerth
- Department of Neurology; Klinikum rechts der Isar, Technische Universität München; Munich Germany
| | - Daniele Carassiti
- Wolfson Neuroscience Laboratories, Division of Brain Sciences, Imperial College Faculty of Medicine, Hammersmith Hospital; London United Kingdom
| | - Barkha Srivastava
- Comprehensive Pneumology Center, Ludwig Maximilians University Munich and Helmholtz Center Munich; Munich Germany
| | - Jens Gempt
- Department of Neurosurgery; Klinikum rechts der Isar, Technische Universität München; Munich Germany
| | - Jürgen Schlegel
- Division of Neuropathology, Institute of Pathology, Klinikum rechts der Isar, Technische Universität München; Munich Germany
| | - Tanja Kuhlmann
- Institute of Neuropathology, University Hospital Münster; Münster Germany
| | - Thomas Korn
- Department of Neurology; Klinikum rechts der Isar, Technische Universität München; Munich Germany
- Munich Cluster for Systems Neurology (SyNergy); Munich Germany
| | - Richard Reynolds
- Wolfson Neuroscience Laboratories, Division of Brain Sciences, Imperial College Faculty of Medicine, Hammersmith Hospital; London United Kingdom
| | - Bernhard Hemmer
- Department of Neurology; Klinikum rechts der Isar, Technische Universität München; Munich Germany
- Munich Cluster for Systems Neurology (SyNergy); Munich Germany
| |
Collapse
|
43
|
Zayas-Santiago A, Agte S, Rivera Y, Benedikt J, Ulbricht E, Karl A, Dávila J, Savvinov A, Kucheryavykh Y, Inyushin M, Cubano LA, Pannicke T, Veh RW, Francke M, Verkhratsky A, Eaton MJ, Reichenbach A, Skatchkov SN. Unidirectional photoreceptor-to-Müller glia coupling and unique K+ channel expression in Caiman retina. PLoS One 2014; 9:e97155. [PMID: 24831221 PMCID: PMC4022631 DOI: 10.1371/journal.pone.0097155] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Accepted: 04/15/2014] [Indexed: 02/07/2023] Open
Abstract
Background Müller cells, the principal glial cells of the vertebrate retina, are fundamental for the maintenance and function of neuronal cells. In most vertebrates, including humans, Müller cells abundantly express Kir4.1 inwardly rectifying potassium channels responsible for hyperpolarized membrane potential and for various vital functions such as potassium buffering and glutamate clearance; inter-species differences in Kir4.1 expression were, however, observed. Localization and function of potassium channels in Müller cells from the retina of crocodiles remain, hitherto, unknown. Methods We studied retinae of the Spectacled caiman (Caiman crocodilus fuscus), endowed with both diurnal and nocturnal vision, by (i) immunohistochemistry, (ii) whole-cell voltage-clamp, and (iii) fluorescent dye tracing to investigate K+ channel distribution and glia-to-neuron communications. Results Immunohistochemistry revealed that caiman Müller cells, similarly to other vertebrates, express vimentin, GFAP, S100β, and glutamine synthetase. In contrast, Kir4.1 channel protein was not found in Müller cells but was localized in photoreceptor cells. Instead, 2P-domain TASK-1 channels were expressed in Müller cells. Electrophysiological properties of enzymatically dissociated Müller cells without photoreceptors and isolated Müller cells with adhering photoreceptors were significantly different. This suggests ion coupling between Müller cells and photoreceptors in the caiman retina. Sulforhodamine-B injected into cones permeated to adhering Müller cells thus revealing a uni-directional dye coupling. Conclusion Our data indicate that caiman Müller glial cells are unique among vertebrates studied so far by predominantly expressing TASK-1 rather than Kir4.1 K+ channels and by bi-directional ion and uni-directional dye coupling to photoreceptor cells. This coupling may play an important role in specific glia-neuron signaling pathways and in a new type of K+ buffering.
Collapse
Affiliation(s)
- Astrid Zayas-Santiago
- Departments of Pathology, Biochemistry and Physiology, Universidad Central Del Caribe, Bayamón, Puerto Rico, United States of America
| | - Silke Agte
- Paul Flechsig Institute of Brain Research, Faculty of Medicine, University of Leipzig, Leipzig, Germany
- Division of Soft Matter Physics, Department of Physics, University of Leipzig, Leipzig, Germany
| | - Yomarie Rivera
- Departments of Pathology, Biochemistry and Physiology, Universidad Central Del Caribe, Bayamón, Puerto Rico, United States of America
| | - Jan Benedikt
- Departments of Pathology, Biochemistry and Physiology, Universidad Central Del Caribe, Bayamón, Puerto Rico, United States of America
| | - Elke Ulbricht
- Paul Flechsig Institute of Brain Research, Faculty of Medicine, University of Leipzig, Leipzig, Germany
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Anett Karl
- Paul Flechsig Institute of Brain Research, Faculty of Medicine, University of Leipzig, Leipzig, Germany
| | - José Dávila
- Departments of Pathology, Biochemistry and Physiology, Universidad Central Del Caribe, Bayamón, Puerto Rico, United States of America
| | - Alexey Savvinov
- Department of Physical Sciences, Universidad de Puerto Rico, Recinto de Río Piedras, Río Piedras, Puerto Rico, United States of America
| | - Yuriy Kucheryavykh
- Departments of Pathology, Biochemistry and Physiology, Universidad Central Del Caribe, Bayamón, Puerto Rico, United States of America
| | - Mikhail Inyushin
- Departments of Pathology, Biochemistry and Physiology, Universidad Central Del Caribe, Bayamón, Puerto Rico, United States of America
| | - Luis A. Cubano
- Departments of Pathology, Biochemistry and Physiology, Universidad Central Del Caribe, Bayamón, Puerto Rico, United States of America
| | - Thomas Pannicke
- Paul Flechsig Institute of Brain Research, Faculty of Medicine, University of Leipzig, Leipzig, Germany
| | | | - Mike Francke
- Paul Flechsig Institute of Brain Research, Faculty of Medicine, University of Leipzig, Leipzig, Germany
- Translational Centre for Regenerative Medicine (TRM) University of Leipzig, Leipzig, Germany
| | - Alexei Verkhratsky
- Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
| | - Misty J. Eaton
- Departments of Pathology, Biochemistry and Physiology, Universidad Central Del Caribe, Bayamón, Puerto Rico, United States of America
| | - Andreas Reichenbach
- Paul Flechsig Institute of Brain Research, Faculty of Medicine, University of Leipzig, Leipzig, Germany
| | - Serguei N. Skatchkov
- Departments of Pathology, Biochemistry and Physiology, Universidad Central Del Caribe, Bayamón, Puerto Rico, United States of America
- * E-mail:
| |
Collapse
|
44
|
Putatunda R, Hala TJ, Chin J, Lepore AC. Chronic at-level thermal hyperalgesia following rat cervical contusion spinal cord injury is accompanied by neuronal and astrocyte activation and loss of the astrocyte glutamate transporter, GLT1, in superficial dorsal horn. Brain Res 2014; 1581:64-79. [PMID: 24833066 DOI: 10.1016/j.brainres.2014.05.003] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Revised: 04/30/2014] [Accepted: 05/03/2014] [Indexed: 12/23/2022]
Abstract
Neuropathic pain is a form of pathological nociception that occurs in a significant portion of traumatic spinal cord injury (SCI) patients, resulting in debilitating and often long-term physical and psychological burdens. While many peripheral and central mechanisms have been implicated in neuropathic pain, central sensitization of dorsal horn spinothalamic tract (STT) neurons is a major underlying substrate. Furthermore, dysregulation of extracellular glutamate homeostasis and chronic astrocyte activation play important underlying roles in persistent hyperexcitability of these superficial dorsal horn neurons. To date, central sensitization and astrocyte changes have not been characterized in cervical SCI-induced neuropathic pain models, despite the fact that a major portion of SCI patients suffer contusion trauma to cervical spinal cord. In this study, we have characterized 2 rat models of unilateral cervical contusion SCI that behaviorally result in chronic persistence of thermal hyperalgesia in the ipsilateral forepaw. In addition, we find that STT neurons are chronically activated in both models when compared to laminectomy-only uninjured rats. Finally, persistent astrocyte activation and significantly reduced expression of the major CNS glutamate transporter, GLT1, in superficial dorsal horn astrocytes are associated with both excitability changes in STT neurons and the neuropathic pain behavioral phenotype. In conclusion, we have characterized clinically-relevant rodent models of cervical contusion-induced neuropathic pain that result in chronic activation of both STT neurons and astrocytes, as well as compromise in astrocyte glutamate transporter expression. These models can be used as important tools to further study mechanisms underlying neuropathic pain post-SCI and to test potential therapeutic interventions.
Collapse
Affiliation(s)
- Rajarshi Putatunda
- Department of Neuroscience, Farber Institute for Neurosciences, Thomas Jefferson University Medical College, 900 Walnut Street, JHN 469, Philadelphia, PA 19107, USA
| | - Tamara J Hala
- Department of Neuroscience, Farber Institute for Neurosciences, Thomas Jefferson University Medical College, 900 Walnut Street, JHN 469, Philadelphia, PA 19107, USA
| | - Jeannie Chin
- Department of Neuroscience, Farber Institute for Neurosciences, Thomas Jefferson University Medical College, 900 Walnut Street, JHN 469, Philadelphia, PA 19107, USA
| | - Angelo C Lepore
- Department of Neuroscience, Farber Institute for Neurosciences, Thomas Jefferson University Medical College, 900 Walnut Street, JHN 469, Philadelphia, PA 19107, USA.
| |
Collapse
|
45
|
Fernández-López B, Valle-Maroto SM, Barreiro-Iglesias A, Rodicio MC. Neuronal release and successful astrocyte uptake of aminoacidergic neurotransmitters after spinal cord injury in lampreys. Glia 2014; 62:1254-69. [PMID: 24733772 DOI: 10.1002/glia.22678] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 03/13/2014] [Accepted: 04/03/2014] [Indexed: 12/27/2022]
Abstract
In contrast to mammals, the spinal cord of lampreys spontaneously recovers from a complete spinal cord injury (SCI). Understanding the differences between lampreys and mammals in their response to SCI could provide valuable information to propose new therapies. Unique properties of the astrocytes of lampreys probably contribute to the success of spinal cord regeneration. The main aim of our study was to investigate, in the sea lamprey, the release of aminoacidergic neurotransmitters and the subsequent astrocyte uptake of these neurotransmitters during the first week following a complete SCI by detecting glutamate, GABA, glycine, Hu and cytokeratin immunoreactivities. This is the first time that aminoacidergic neurotransmitter release from neurons and the subsequent astrocytic response after SCI are analysed by immunocytochemistry in any vertebrate. Spinal injury caused the immediate loss of glutamate, GABA and glycine immunoreactivities in neurons close to the lesion site (except for the cerebrospinal fluid-contacting GABA cells). Only after SCI, astrocytes showed glutamate, GABA and glycine immunoreactivity. Treatment with an inhibitor of glutamate transporters (DL-TBOA) showed that neuronal glutamate was actively transported into astrocytes after SCI. Moreover, after SCI, a massive accumulation of inhibitory neurotransmitters around some reticulospinal axons was observed. Presence of GABA accumulation significantly correlated with a higher survival ability of these neurons. Our data show that, in contrast to mammals, astrocytes of lampreys have a high capacity to actively uptake glutamate after SCI. GABA may play a protective role that could explain the higher regenerative and survival ability of specific descending neurons of lampreys.
Collapse
Affiliation(s)
- Blanca Fernández-López
- Department of Cell Biology and Ecology, CIBUS, University of Santiago de Compostela, 15782, Santiago de Compostela, Spain
| | | | | | | |
Collapse
|
46
|
Nwaobi SE, Lin E, Peramsetty SR, Olsen ML. DNA methylation functions as a critical regulator of Kir4.1 expression during CNS development. Glia 2014; 62:411-27. [PMID: 24415225 DOI: 10.1002/glia.22613] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Revised: 10/29/2013] [Accepted: 11/21/2013] [Indexed: 12/22/2022]
Abstract
Kir4.1, a glial-specific K+ channel, is critical for normal CNS development. Studies using both global and glial-specific knockout of Kir4.1 reveal abnormal CNS development with the loss of the channel. Specifically, Kir4.1 knockout animals are characterized by ataxia, severe hypomyelination, and early postnatal death. Additionally, Kir4.1 has emerged as a key player in several CNS diseases. Notably, decreased Kir4.1 protein expression occurs in several human CNS pathologies including CNS ischemic injury, spinal cord injury, epilepsy, ALS, and Alzheimer's disease. Despite the emerging significance of Kir4.1 in normal and pathological conditions, its mechanisms of regulation are unknown. Here, we report the first epigenetic regulation of a K+ channel in the CNS. Robust developmental upregulation of Kir4.1 expression in rats is coincident with reductions in DNA methylation of the Kir4.1 gene, KCNJ10. Chromatin immunoprecipitation reveals a dynamic interaction between KCNJ10 and DNA methyltransferase 1 during development. Finally, demethylation of the KCNJ10 promoter is necessary for transcription. These findings indicate DNA methylation is a key regulator of Kir4.1 transcription. Given the essential role of Kir4.1 in normal CNS development, understanding the regulation of this K+ channel is critical to understanding normal glial biology.
Collapse
Affiliation(s)
- Sinifunanya E Nwaobi
- Department of Cell, Developmental and Integrative Biology, Center for Glial Biology in Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | | | | | | |
Collapse
|
47
|
Zuidema JM, Hyzinski-García MC, Van Vlasselaer K, Zaccor NW, Plopper GE, Mongin AA, Gilbert RJ. Enhanced GLT-1 mediated glutamate uptake and migration of primary astrocytes directed by fibronectin-coated electrospun poly-L-lactic acid fibers. Biomaterials 2013; 35:1439-49. [PMID: 24246642 DOI: 10.1016/j.biomaterials.2013.10.079] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 10/27/2013] [Indexed: 12/17/2022]
Abstract
Bioengineered fiber substrates are increasingly studied as a means to promote regeneration and remodeling in the injured central nervous system (CNS). Previous reports largely focused on the ability of oriented scaffolds to bridge injured regions and direct outgrowth of axonal projections. In the present work, we explored the effects of electrospun microfibers on the migration and physiological properties of brain astroglial cells. Primary rat astrocytes were cultured on either fibronectin-coated poly-L-lactic acid (PLLA) films, fibronectin-coated randomly oriented PLLA electrospun fibers, or fibronectin-coated aligned PLLA electrospun fibers. Aligned PLLA fibers strongly altered astrocytic morphology, orienting cell processes, actin microfilaments, and microtubules along the length of the fibers. On aligned fibers, astrocytes also significantly increased their migration rates in the direction of fiber orientation. We further investigated if fiber topography modifies astrocytic neuroprotective properties, namely glutamate and glutamine transport and metabolism. This was done by quantifying changes in mRNA expression (qRT-PCR) and protein levels (Western blotting) for a battery of relevant biomolecules. Interestingly, we found that cells grown on random and/or aligned fibers increased the expression levels of two glutamate transporters, GLAST and GLT-1, and an important metabolic enzyme, glutamine synthetase, as compared to the fibronectin-coated films. Functional assays revealed increases in glutamate transport rates due to GLT-1 mediated uptake, which was largely determined by the dihydrokainate-sensitive GLT-1. Overall, this study suggests that aligned PLLA fibers can promote directed astrocytic migration, and, of most importance, our in vitro results indicate for the first time that electrospun PLLA fibers can positively modify neuroprotective properties of glial cells by increasing rates of glutamate uptake.
Collapse
Affiliation(s)
- Jonathan M Zuidema
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA; Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - María C Hyzinski-García
- Center for Neuropharmacology and Neuroscience, Albany Medical College, Albany, NY 12208, USA
| | - Kristien Van Vlasselaer
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA; Department of Biology, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - Nicholas W Zaccor
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA; Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - George E Plopper
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA; Department of Biology, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - Alexander A Mongin
- Center for Neuropharmacology and Neuroscience, Albany Medical College, Albany, NY 12208, USA
| | - Ryan J Gilbert
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA; Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, USA.
| |
Collapse
|
48
|
Ghanbari A, Asgari AR, Kaka GR, Falahatpishe HR, Naderi A, Jorjani M. In vivo microdialysis of glutamate in ventroposterolateral nucleus of thalamus following electrolytic lesion of spinothalamic tract in rats. Exp Brain Res 2013; 232:415-21. [PMID: 24186197 DOI: 10.1007/s00221-013-3749-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2013] [Accepted: 10/14/2013] [Indexed: 01/08/2023]
Abstract
Central pain is one of the most important complications after spinal cord injury (SCI), and thereby, its treatment raises many challenges. After SCI, in a cascade of molecular events, a marked increase in glutamate at the injury site results in secondary changes which may impact on supraspinal regions, mainly ventroposterolateral (VPL). There is little information about the changes in glutamate metabolism in the VPL and whether it contributes to SCI-related central pain. The present study was performed to evaluate glutamate release in the VPL following electrolytic lesion of spinothalamic tract (STT). A laminectomy was performed at spinal segments of T9-T10 in male rats, and then, unilateral electrolytic lesions were made in the STT. Glutamate concentrations in ipsilateral VPL dialysate were measured by HPLC method at days 3, 7, 14, 21 and 28 post-injury. Tactile pain and motor activity were also examined. Glutamate levels were significantly increased in ipsilateral VPL of spinal-cord-injured rats 2 weeks after SCI and remained high up to day 28 post-surgery. The STT lesions had no marked effect on our measures of motor activity, but there was a significant decrease in paw withdrawal threshold in the hind paws at day 14 post-SCI. These findings suggest that an increased release of glutamate in VPL plays a role in secondary pathologic changes, leading to neuronal hyperexcitation and neuropathic pain after SCI.
Collapse
Affiliation(s)
- A Ghanbari
- Applied Neuroscience Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | | | | | | | | | | |
Collapse
|
49
|
Sohrabji F, Bake S, Lewis DK. Age-related changes in brain support cells: Implications for stroke severity. Neurochem Int 2013; 63:291-301. [PMID: 23811611 PMCID: PMC3955169 DOI: 10.1016/j.neuint.2013.06.013] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Revised: 05/31/2013] [Accepted: 06/19/2013] [Indexed: 12/14/2022]
Abstract
Stroke is one of the leading causes of adult disability and the fourth leading cause of mortality in the US. Stroke disproportionately occurs among the elderly, where the disease is more likely to be fatal or lead to long-term supportive care. Animal models, where the ischemic insult can be controlled more precisely, also confirm that aged animals sustain more severe strokes as compared to young animals. Furthermore, the neuroprotection usually seen in younger females when compared to young males is not observed in older females. The preclinical literature thus provides a valuable resource for understanding why the aging brain is more susceptible to severe infarction. In this review, we discuss the hypothesis that stroke severity in the aging brain may be associated with reduced functional capacity of critical support cells. Specifically, we focus on astrocytes, that are critical for detoxification of the brain microenvironment and endothelial cells, which play a crucial role in maintaining the blood brain barrier. In view of the sex difference in stroke severity, this review also discusses studies of middle-aged acyclic females as well as the effects of the estrogen on astrocytes and endothelial cells.
Collapse
Affiliation(s)
- Farida Sohrabji
- Department of Neuroscience and Experimental Therapeutics, Women's Health in Neuroscience Program, Texas A&M HSC College of Medicine, Bryan, TX 77807, United States.
| | | | | |
Collapse
|
50
|
Gupta RK, Prasad S. Early down regulation of the glial Kir4.1 and GLT-1 expression in pericontusional cortex of the old male mice subjected to traumatic brain injury. Biogerontology 2013; 14:531-41. [PMID: 24026668 DOI: 10.1007/s10522-013-9459-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Accepted: 08/27/2013] [Indexed: 10/26/2022]
Abstract
Astroglia play multiple roles in brain function by providing matrix to neurons, secreting neurotrophic factors, maintaining K(+) and glutamate homeostasis and thereby controlling synaptic plasticity which undergoes alterations during aging. K(+) and glutamate homeostasis is maintained by astrocytes membrane bound inwardly rectifying K(+) channel (Kir4.1) and glutamate transporter-1 (GLT-1 or EAAT-2) proteins, respectively in the synapse and their expression may be altered due to traumatic brain injury (TBI). Also, it is not well understood whether this change is age dependent. To find out this, TBI was experimentally induced in adult and old male AKR strain mice using CHI technique, and expression of the Kir4.1 and GLT-1 in the pericontusional cortex at various time intervals was studied by Western blotting and semi quantitative RT-PCR techniques. Here, we report that expression of both Kir4.1 and GLT-1 genes at transcript and protein levels is significantly down regulated in the pericontusional ipsi-lateral cortex of old TBI mice as compared to that in the adult TBI mice as function of time after injury. Further, expression of both the genes starts decreasing early in old mice i.e., from the first hour after TBI as compared to that starts from fourth hour in adult TBI mice. Thus TBI affects expression of Kir4.1 and GLT-1 genes in age- and time dependent manner and it may lead to accumulations of more K(+) and glutamate early in the synapse of old mice as compared to adult. This may be implicated in the TBI induced early and severe neuronal depolarization and excito-neurotoxicity in old age.
Collapse
Affiliation(s)
- R K Gupta
- Biochemistry and Molecular Biology Laboratory, Department of Zoology, Banaras Hindu University, Varanasi, 221005, Uttar Pradesh, India
| | | |
Collapse
|