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Wan Y, Holste KG, Ye F, Hua Y, Keep RF, Xi G. Minocycline attenuates hydrocephalus and inhibits iron accumulation, ependymal damage and epiplexus cell activation after intraventricular hemorrhage in aged rats. Exp Neurol 2023; 369:114523. [PMID: 37652293 PMCID: PMC10642526 DOI: 10.1016/j.expneurol.2023.114523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 08/24/2023] [Accepted: 08/28/2023] [Indexed: 09/02/2023]
Abstract
Intracerebral hemorrhage is primarily a disease of the elderly and it is frequently accompanied by intraventricular hemorrhage (IVH) which can lead to posthemorrhagic hydrocephalus and poor prognosis. Red blood cell iron has been implicated in brain injury after cerebral hemorrhage. The current study examined using T2* magnetic resonance imaging (MRI) to detect periventricular iron deposition after IVH and investigated the effects of minocycline on hydrocephalus in an aged rat IVH model. It had three parts. In part 1, male aged rats received a 200 μl injection of saline or autologous blood into the lateral ventricle and were euthanized at day 14. In parts 2 and 3, aged IVH rats were treated with vehicle or minocycline and euthanized at day 7 or 14. Rats underwent MRI to quantify hydrocephalus and iron deposition followed by brain histology and immunohistochemistry. Periventricular iron overload was found after IVH using T2* MRI and confirmed by histology. IVH also caused ventricular wall damage and increased the number of CD68(+) choroid plexus epiplexus cells. Minocycline administration reduced iron deposition and ventricular volume at days 7 and 14 after IVH, as well as ventricle wall damage and epiplexus cell activation. In summary, IVH-induced hydrocephalus is associated with periventricular iron deposition, ependymal damage and choroid plexus epiplexus cell activation in aged rats. Minocycline attenuated those effects and might be a potential treatment for posthemorrhagic hydrocephalus in the elderly.
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Affiliation(s)
- Yingfeng Wan
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA
| | | | - Fenghui Ye
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA
| | - Ya Hua
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA
| | - Richard F Keep
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA
| | - Guohua Xi
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA.
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Brown FN, Iwasawa E, Shula C, Fugate EM, Lindquist DM, Mangano FT, Goto J. Early postnatal microglial ablation in the Ccdc39 mouse model reveals adverse effects on brain development and in neonatal hydrocephalus. Fluids Barriers CNS 2023; 20:42. [PMID: 37296418 DOI: 10.1186/s12987-023-00433-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 04/19/2023] [Indexed: 06/12/2023] Open
Abstract
BACKGROUND Neonatal hydrocephalus is a congenital abnormality resulting in an inflammatory response and microglial cell activation both clinically and in animal models. Previously, we reported a mutation in a motile cilia gene, Ccdc39 that develops neonatal progressive hydrocephalus (prh) with inflammatory microglia. We discovered significantly increased amoeboid-shaped activated microglia in periventricular white matter edema, reduced mature homeostatic microglia in grey matter, and reduced myelination in the prh model. Recently, the role of microglia in animal models of adult brain disorders was examined using cell type-specific ablation by colony-stimulating factor-1 receptor (CSF1R) inhibitor, however, little information exists regarding the role of microglia in neonatal brain disorders such as hydrocephalus. Therefore, we aim to see if ablating pro-inflammatory microglia, and thus suppressing the inflammatory response, in a neonatal hydrocephalic mouse line could have beneficial effects. METHODS In this study, Plexxikon 5622 (PLX5622), a CSF1R inhibitor, was subcutaneously administered to wild-type (WT) and prh mutant mice daily from postnatal day (P) 3 to P7. MRI-estimated brain volume was compared with untreated WT and prh mutants P7-9 and immunohistochemistry of the brain sections was performed at P8 and P18-21. RESULTS PLX5622 injections successfully ablated IBA1-positive microglia in both the WT and prh mutants at P8. Of the microglia that are resistant to PLX5622 treatment, there was a higher percentage of amoeboid-shaped microglia, identified by morphology with retracted processes. In PLX-treated prh mutants, there was increased ventriculomegaly and no change in the total brain volume was observed. Also, the PLX5622 treatment significantly reduced myelination in WT mice at P8, although this was recovered after full microglia repopulation by P20. Microglia repopulation in the mutants worsened hypomyelination at P20. CONCLUSIONS Microglia ablation in the neonatal hydrocephalic brain does not improve white matter edema, and actually worsens ventricular enlargement and hypomyelination, suggesting critical functions of homeostatic ramified microglia to better improve brain development with neonatal hydrocephalus. Future studies with detailed examination of microglial development and status may provide a clarification of the need for microglia in neonatal brain development.
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Affiliation(s)
- Farrah N Brown
- Division of Pediatric Neurosurgery, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Eri Iwasawa
- Division of Pediatric Neurosurgery, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Crystal Shula
- Division of Pediatric Neurosurgery, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Elizabeth M Fugate
- Department of Radiology, Imaging Research Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Diana M Lindquist
- Department of Radiology, Imaging Research Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Francesco T Mangano
- Division of Pediatric Neurosurgery, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
- Department of Neurosurgery, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - June Goto
- Division of Pediatric Neurosurgery, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
- Department of Neurosurgery, University of Cincinnati College of Medicine, Cincinnati, OH, USA.
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Bian C, Wan Y, Koduri S, Hua Y, Keep RF, Xi G. Iron-Induced Hydrocephalus: the Role of Choroid Plexus Stromal Macrophages. Transl Stroke Res 2023; 14:238-249. [PMID: 35543803 PMCID: PMC9794223 DOI: 10.1007/s12975-022-01031-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 04/28/2022] [Accepted: 04/29/2022] [Indexed: 12/30/2022]
Abstract
Evidence indicates that erythrocyte-derived iron and inflammation both play a role in intraventricular hemorrhage-induced brain injury including hydrocephalus. Many immune-associated cells, primarily stromal macrophages, reside at the choroid plexus where they are involved in inflammatory responses and antigen presentation. However, whether intraventricular iron impacts those stromal cells is unknown. The aim of this study was to evaluate the relationship between choroid plexus stromal macrophages and iron-induced hydrocephalus in rats and the impact of minocycline and clodronate liposomes on those changes. Aged (18-month-old) and young (3-month-old) male Fischer 344 rats were used to study choroid plexus stromal macrophages. Rats underwent intraventricular iron injection to induce hydrocephalus and treated with either minocycline, a microglia/macrophage inhibitor, or clodronate liposomes, a macrophage depleting agent. Ventricular volume was measured using magnetic resonance imaging, and stromal macrophages were quantified by immunofluorescence staining. We found that stromal macrophages accounted for about 10% of the total choroid plexus cells with more in aged rats. In both aged and young rats, intraventricular iron injection resulted in hydrocephalus and increased stromal macrophage number. Minocycline or clodronate liposomes ameliorated iron-induced hydrocephalus and the increase in stromal macrophages. In conclusion, stromal macrophages account for ~10% of all choroid plexus cells, with more in aged rats. Treatments targeting macrophages (minocycline and clodronate liposomes) are associated with reduced iron-induced hydrocephalus.
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Affiliation(s)
- Chaoyi Bian
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA
- Department of Neurosurgery, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou, China
| | - Yingfeng Wan
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA
| | - Sravanthi Koduri
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA
| | - Ya Hua
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA
| | - Richard F Keep
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA
| | - Guohua Xi
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA.
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Femi-Akinlosotu OM, Olopade FE, Obiako J, Olopade JO, Shokunbi MT. Vanadium improves memory and spatial learning and protects the pyramidal cells of the hippocampus in juvenile hydrocephalic mice. Front Neurol 2023; 14:1116727. [PMID: 36846142 PMCID: PMC9947794 DOI: 10.3389/fneur.2023.1116727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 01/23/2023] [Indexed: 02/11/2023] Open
Abstract
Background Hydrocephalus is a neurological condition known to cause learning and memory disabilities due to its damaging effect on the hippocampal neurons, especially pyramidal neurons. Vanadium at low doses has been observed to improve learning and memory abilities in neurological disorders but it is uncertain whether such protection will be provided in hydrocephalus. We investigated the morphology of hippocampal pyramidal neurons and neurobehavior in vanadium-treated and control juvenile hydrocephalic mice. Methods Hydrocephalus was induced by intra-cisternal injection of sterile-kaolin into juvenile mice which were then allocated into 4 groups of 10 pups each, with one group serving as an untreated hydrocephalic control while others were treated with 0.15, 0.3 and 3 mg/kg i.p of vanadium compound respectively, starting 7 days post-induction for 28 days. Non-hydrocephalic sham controls (n = 10) were sham operated without any treatment. Mice were weighed before dosing and sacrifice. Y-maze, Morris Water Maze and Novel Object Recognition tests were carried out before the sacrifice, the brains harvested, and processed for Cresyl Violet and immunohistochemistry for neurons (NeuN) and astrocytes (GFAP). The pyramidal neurons of the CA1 and CA3 regions of the hippocampus were assessed qualitatively and quantitatively. Data were analyzed using GraphPad prism 8. Results Escape latencies of vanadium-treated groups were significantly shorter (45.30 ± 26.30 s, 46.50 ± 26.35 s, 42.99 ± 18.44 s) than untreated group (62.06 ± 24.02 s) suggesting improvements in learning abilities. Time spent in the correct quadrant was significantly shorter in the untreated group (21.19 ± 4.15 s) compared to control (34.15 ± 9.44 s) and 3 mg/kg vanadium-treated group (34.35 ± 9.74 s). Recognition index and mean % alternation were lowest in untreated group (p = 0.0431, p=0.0158) suggesting memory impairments, with insignificant improvements in vanadium-treated groups. NeuN immuno-stained CA1 revealed loss of apical dendrites of the pyramidal cells in untreated hydrocephalus group relative to control and a gradual reversal attempt in the vanadium-treated groups. Astrocytic activation (GFAP stain) in the untreated hydrocephalus group were attenuated in the vanadium-treated groups under the GFAP stain. Pyknotic index in CA1 pyramidal layer of untreated (18.82 ± 2.59) and 0.15mg/kg vanadium-treated groups (18.14 ± 5.92) were significantly higher than control (11.11 ± 0.93; p = 0.0205, p = 0.0373) while there was no significant difference in CA3 pyknotic index across all groups. Conclusion Our results suggest that vanadium has a dose-dependent protective effect on the pyramidal cells of the hippocampus and on memory and spatial learning functions in juvenile hydrocephalic mice.
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Affiliation(s)
| | - Funmilayo Eniola Olopade
- Developmental Neurobiology Laboratory, Department of Anatomy, College of Medicine, University of Ibadan, Ibadan, Nigeria
| | - Jane Obiako
- Developmental Neurobiology Laboratory, Department of Anatomy, College of Medicine, University of Ibadan, Ibadan, Nigeria
| | - James Olukayode Olopade
- Neuroscience Unit, Department of Veterinary Anatomy, Faculty of Veterinary Medicine, University of Ibadan, Ibadan, Nigeria
| | - Matthew Temitayo Shokunbi
- Developmental Neurobiology Laboratory, Department of Anatomy, College of Medicine, University of Ibadan, Ibadan, Nigeria,Division of Neurological Surgery, Department of Surgery, University of Ibadan, Ibadan, Nigeria,*Correspondence: Matthew Temitayo Shokunbi ✉
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Hasanain AA, Soliman MAR, Elwy R, Ezzat AAM, Abdel-Bari SH, Marx S, Jenkins A, El Refaee E, Zohdi A. An eye on the future for defeating hydrocephalus, ciliary dyskinesia-related hydrocephalus: review article. Br J Neurosurg 2022; 36:329-339. [PMID: 35579079 DOI: 10.1080/02688697.2022.2074373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Congenital hydrocephalus affects approximately one in 1000 newborn children and is fatal in approximately 50% of untreated cases. The currently known management protocols usually necessitate multiple interventions and long-term use of healthcare resources due to a relatively high incidence of complications, and many of them mostly provide a treatment of the effect rather than the cause of cerebrospinal fluid flow reduction or outflow obstruction. Future studies discussing etiology specific hydrocephalus alternative treatments are needed. We systematically reviewed the available literature on the effect of ciliary abnormality on congenital hydrocephalus pathogenesis, to open a discussion on the feasibility of factoring ciliary abnormality in future research on hydrocephalus treatment modalities. Although there are different forms of ciliopathies, we focused in this review on primary ciliary dyskinesia. There is growing evidence of association of other ciliary syndromes and hydrocephalus, such as the reduced generation of multiple motile cilia, which is distinct from primary ciliary dyskinesia. Data for this review were identified by searching PubMed using the search terms 'hydrocephalus,' 'Kartagener syndrome,' 'primary ciliary dyskinesia,' and 'immotile cilia syndrome.' Only articles published in English and reporting human patients were included. Seven studies met our inclusion criteria, reporting 12 cases of hydrocephalus associated with primary ciliary dyskinesia. The patients had variable clinical presentations, genetic backgrounds, and ciliary defects. The ependymal water propelling cilia differ in structure and function from the mucus propelling cilia, and there is a possibility of isolated non-syndromic ependymal ciliopathy causing only hydrocephalus with growing evidence in the literature for the association ependymal ciliary abnormality and hydrocephalus. Abdominal and thoracic situs in children with hydrocephalus can be evaluated, and secondary damage of ependymal cilia causing hydrocephalus in cases with generalized ciliary abnormality can be considered.
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Affiliation(s)
| | - Mohamed A R Soliman
- Department of Neurosurgery, Cairo University, Cairo, Egypt.,Department of Neurosurgery, Jacobs School of Medicine and Biomedical Sciences at University at Buffalo, Buffalo, New York, USA
| | - Reem Elwy
- Department of Neurosurgery, Cairo University, Cairo, Egypt
| | | | | | - Sascha Marx
- Department of Neurosurgery, University Medicine Greifswald, Greifswald, Germany
| | - Alistair Jenkins
- Department of Neurosurgery Royal Victoria Infirmary, Newcastle-upon-Tyne, United Kingdom
| | - Ehab El Refaee
- Department of Neurosurgery, Cairo University, Cairo, Egypt.,Department of Neurosurgery, University Medicine Greifswald, Greifswald, Germany
| | - Ahmed Zohdi
- Department of Neurosurgery, Cairo University, Cairo, Egypt
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Castañeyra-Ruiz L, González-Marrero I, Hernández-Abad LG, Carmona-Calero EM, Pardo MR, Baz-Davila R, Lee S, Muhonen M, Borges R, Castañeyra-Perdomo A. AQP4 labels a subpopulation of white matter-dependent glial radial cells affected by pediatric hydrocephalus, and its expression increased in glial microvesicles released to the cerebrospinal fluid in obstructive hydrocephalus. Acta Neuropathol Commun 2022; 10:41. [PMID: 35346374 PMCID: PMC8962176 DOI: 10.1186/s40478-022-01345-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 03/11/2022] [Indexed: 01/16/2023] Open
Abstract
Hydrocephalus is a distension of the ventricular system associated with ventricular zone disruption, reactive astrogliosis, periventricular white matter ischemia, axonal impairment, and corpus callosum alterations. The condition's etiology is typically attributed to a malfunction in classical cerebrospinal fluid (CSF) bulk flow; however, this approach does not consider the unique physiology of CSF in fetal and perinatal patients. The parenchymal fluid contributes to the glymphatic system, and plays a fundamental role in pediatric hydrocephalus, with aquaporin 4 (AQP4) as the primary facilitator of these fluid movements. Despite the importance of AQP4 in the pathophysiology of hydrocephalus, it’s expression in human fetal life is not well-studied. This manuscript systematically defines the brain expression of AQP4 in human brain development under control (n = 13) and hydrocephalic conditions (n = 3). Brains from 8 postconceptional weeks (PCW) onward and perinatal CSF from control (n = 2), obstructive (n = 6) and communicating (n = 6) hydrocephalic samples were analyzed through immunohistochemistry, immunofluorescence, western blot, and flow cytometry. Our results indicate that AQP4 expression is observed first in the archicortex, followed by the ganglionic eminences and then the neocortex. In the neocortex, it is initially at the perisylvian regions, and lastly at the occipital and prefrontal zones. Characteristic astrocyte end-feet labeling surrounding the vascular system was not established until 25 PCW. We also found AQP4 expression in a subpopulation of glial radial cells with processes that do not progress radially but, rather, curve following white matter tracts (corpus callosum and fornix), which were considered as glial stem cells (GSC). Under hydrocephalic conditions, GSC adjacent to characteristic ventricular zone disruption showed signs of early differentiation into astrocytes which may affect normal gliogenesis and contribute to the white matter dysgenesis. Finally, we found that AQP4 is expressed in the microvesicle fraction (p < 0.01) of CSF from patients with obstructive hydrocephalus. These findings suggest the potential use of AQP4 as a diagnostic and prognostic marker of pediatric hydrocephalus and as gliogenesis biomarker.
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Iwasawa E, Brown FN, Shula C, Kahn F, Lee SH, Berta T, Ladle DR, Campbell K, Mangano FT, Goto J. The Anti-Inflammatory Agent Bindarit Attenuates the Impairment of Neural Development through Suppression of Microglial Activation in a Neonatal Hydrocephalus Mouse Model. J Neurosci 2022; 42:1820-1844. [PMID: 34992132 PMCID: PMC8896558 DOI: 10.1523/jneurosci.1160-21.2021] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 11/30/2021] [Accepted: 12/17/2021] [Indexed: 11/21/2022] Open
Abstract
Neonatal hydrocephalus presents with various degrees of neuroinflammation and long-term neurologic deficits in surgically treated patients, provoking a need for additional medical treatment. We previously reported elevated neuroinflammation and severe periventricular white matter damage in the progressive hydrocephalus (prh) mutant which contains a point mutation in the Ccdc39 gene, causing loss of cilia-mediated unidirectional CSF flow. In this study, we identified cortical neuropil maturation defects such as impaired excitatory synapse maturation and loss of homeostatic microglia, and swimming locomotor defects in early postnatal prh mutant mice. Strikingly, systemic application of the anti-inflammatory small molecule bindarit significantly supports healthy postnatal cerebral cortical development in the prh mutant. While bindarit only mildly reduced the ventricular volume, it significantly improved the edematous appearance and myelination of the corpus callosum. Moreover, the treatment attenuated thinning in cortical Layers II-IV, excitatory synapse formation, and interneuron morphogenesis, by supporting the ramified-shaped homeostatic microglia from excessive cell death. Also, the therapeutic effect led to the alleviation of a spastic locomotor phenotype of the mutant. We found that microglia, but not peripheral monocytes, contribute to amoeboid-shaped activated myeloid cells in prh mutants' corpus callosum and the proinflammatory cytokines expression. Bindarit blocks nuclear factor (NF)-kB activation and its downstream proinflammatory cytokines, including monocyte chemoattractant protein-1, in the prh mutant. Collectively, we revealed that amelioration of neuroinflammation is crucial for white matter and neuronal maturation in neonatal hydrocephalus. Future studies of bindarit treatment combined with CSF diversion surgery may provide long-term benefits supporting neuronal development in neonatal hydrocephalus.SIGNIFICANCE STATEMENT In neonatal hydrocephalus, little is known about the signaling cascades of neuroinflammation or the impact of such inflammatory insults on neural cell development within the perinatal cerebral cortex. Here, we report that proinflammatory activation of myeloid cells, the majority of which are derived from microglia, impairs periventricular myelination and cortical neuronal maturation using the mouse prh genetic model of neonatal hydrocephalus. Administration of bindarit, an anti-inflammatory small molecule that blocks nuclear factor (NF)-kB activation, restored the cortical thinning and synaptic maturation defects in the prh mutant brain through suppression of microglial activation. These data indicate the potential therapeutic use of anti-inflammatory reagents targeting neuroinflammation in the treatment of neonatal hydrocephalus.
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Affiliation(s)
- Eri Iwasawa
- Division of Pediatric Neurosurgery, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, 45242
| | - Farrah N Brown
- Division of Pediatric Neurosurgery, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, 45242
| | - Crystal Shula
- Division of Pediatric Neurosurgery, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, 45242
| | - Fatima Kahn
- Division of Pediatric Neurosurgery, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, 45242
| | - Sang Hoon Lee
- Pain Research Center, Department of Anesthesiology, University of Cincinnati Medical Center, Cincinnati, Ohio, 45242
| | - Temugin Berta
- Pain Research Center, Department of Anesthesiology, University of Cincinnati Medical Center, Cincinnati, Ohio, 45242
| | - David R Ladle
- Department of Neuroscience, Cell Biology, and Physiology, Wright State University, Dayton, Ohio, 45435
| | - Kenneth Campbell
- Division of Pediatric Neurosurgery, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, 45242
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, Ohio, 45242
| | - Francesco T Mangano
- Division of Pediatric Neurosurgery, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, 45242
- Department of Neurosurgery, University of Cincinnati College of Medicine, Cincinnati, Ohio, 45242
| | - June Goto
- Division of Pediatric Neurosurgery, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, 45242
- Department of Neurosurgery, University of Cincinnati College of Medicine, Cincinnati, Ohio, 45242
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8
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Hao X, Ye F, Holste KG, Hua Y, Garton HJL, Keep RF, Xi G. Delayed Minocycline Treatment Ameliorates Hydrocephalus Development and Choroid Plexus Inflammation in Spontaneously Hypertensive Rats. Int J Mol Sci 2022; 23:2306. [PMID: 35216420 PMCID: PMC8874790 DOI: 10.3390/ijms23042306] [Citation(s) in RCA: 4] [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: 12/09/2021] [Revised: 02/14/2022] [Accepted: 02/17/2022] [Indexed: 12/15/2022] Open
Abstract
Hydrocephalus is a complicated disorder that affects both adult and pediatric populations. The mechanism of hydrocephalus development, especially when there is no mass lesion present causing an obstructive, is poorly understood. Prior studies have demonstrated that spontaneously hypertensive rats (SHRs) develop hydrocephalus by week 7, which was attenuated with minocycline. The aim of this study was to determine sex differences in hydrocephalus development and to examine the effect of minocycline administration after hydrocephalus onset. Male and female Wistar-Kyoto rats (WKYs) and SHRs underwent magnetic resonance imaging at weeks 7 and 9 to determine ventricular volume. Choroid plexus epiplexus cell activation, cognitive deficits, white matter atrophy, and hippocampal neuronal loss were examined at week 9. In the second phase of the experiment, male SHRs (7 weeks old) were treated with either saline or minocycline (20 mg/kg) for 14 days, and similar radiologic, histologic, and behavior tests were performed. Hydrocephalus was present at week 7 and increased at week 9 in both male and female SHRs, which was associated with greater epiplexus cell activation than WKYs. Male SHRs had greater ventricular volume and epiplexus cell activation compared to female SHRs. Minocycline administration improved cognitive function, white matter atrophy, and hippocampal neuronal cell loss. In conclusion, while both male and female SHRs developed hydrocephalus and epiplexus cell activation by week 9, it was more severe in males. Delayed minocycline treatment alleviated hydrocephalus, epiplexus macrophage activation, brain pathology, and cognitive impairment in male SHRs.
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Affiliation(s)
| | | | | | | | | | | | - Guohua Xi
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI 48109, USA; (X.H.); (F.Y.); (K.G.H.); (Y.H.); (H.J.L.G.); (R.F.K.)
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9
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Tang J, Jila S, Luo T, Zhang B, Miao H, Feng H, Chen Z, Zhu G. C3/C3aR inhibition alleviates GMH-IVH-induced hydrocephalus by preventing microglia-astrocyte interactions in neonatal rats. Neuropharmacology 2021; 205:108927. [PMID: 34921829 DOI: 10.1016/j.neuropharm.2021.108927] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Revised: 12/02/2021] [Accepted: 12/13/2021] [Indexed: 01/22/2023]
Abstract
Activation of microglia and astrocytes following germinal matrix hemorrhage and intraventricular hemorrhage (GMH-IVH) plays a detrimental role in posthemorrhagic hydrocephalus (PHH). It is still unclear whether or how an interaction occurs between microglia and astrocytes in PHH. Here, we investigated the role of the C3/C3aR pathway in microglia and astrocyte interactions and whether C3/C3aR-targeted inhibition could alleviate PHH following GMH-IVH. A total of 152 Sprague-Dawley rats at postnatal day seven (P7) were enrolled in the study, and collagenase VII was used to induce GMH-IVH. Minocycline (45 mg/kg) was administered to inhibit microglial activation. Complement C3a peptide and C3aR antagonist (SB 290157, 10 mg/kg) were used to regulate the C3/C3aR pathway. As a result, the data demonstrated that periventricular C3aR+/Iba-1+ microglia and C3+/GFAP+ astrocytes were significantly increased in GMH-IVH pups at 28 days after surgery. Intranasal C3a peptide upregulated C3aR expression in microglia. Inhibition of microglia by minocycline decreased both C3+/GFAP+ astrocytes and the colocalization volume of Iba-1 and GFAP. In addition, intraperitoneally injected C3aRA alleviated the periventricular colocalization volume of microglia and astrocytes. Compared with vehicle-treated pups, the protein level of IL-1β, IL-6 and TNF-α in cerebral spinal fluid and brain tissue at 28 days following GMH-IVH were reduced in C3aRA-treated pups. Moreover, hydrocephalus was alleviated, and long-term cognitive ability were improved in the C3aRA-treated group. Our data presented simultaneous periventricular astrogliosis and microgliosis of pups following GMH-IVH and proved their potential interaction through the C3/C3aR pathway, indicating C3aRA as a potential pharmacological treatment of PHH in neonates.
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Affiliation(s)
- Jun Tang
- Department of Neurosurgery, Southwest Hospital, Army Medical University (Third Military Medical University), Chongqing, 400038, China
| | - Shiju Jila
- Department of Neurosurgery, Southwest Hospital, Army Medical University (Third Military Medical University), Chongqing, 400038, China
| | - Tiantian Luo
- Department of Neurobiology, Army Medical University (Third Military Medical University), Chongqing, 400038, China
| | - Bo Zhang
- Department of Neurosurgery, Southwest Hospital, Army Medical University (Third Military Medical University), Chongqing, 400038, China
| | - Hongping Miao
- Department of Neurosurgery, Southwest Hospital, Army Medical University (Third Military Medical University), Chongqing, 400038, China
| | - Hua Feng
- Department of Neurosurgery, Southwest Hospital, Army Medical University (Third Military Medical University), Chongqing, 400038, China
| | - Zhi Chen
- Department of Neurosurgery, Southwest Hospital, Army Medical University (Third Military Medical University), Chongqing, 400038, China
| | - Gang Zhu
- Department of Neurosurgery, Southwest Hospital, Army Medical University (Third Military Medical University), Chongqing, 400038, China.
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The association of Edaravone with shunt surgery improves behavioral performance, reduces astrocyte reaction and apoptosis, and promotes neuroprotection in young hydrocephalic rats. J Chem Neuroanat 2021; 119:102059. [PMID: 34896559 DOI: 10.1016/j.jchemneu.2021.102059] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 10/24/2021] [Accepted: 12/06/2021] [Indexed: 11/22/2022]
Abstract
The neuroprotective effect of Edaravone in young hydrocephalic rats associated with a CSF derivation system was evaluated. The drug has already been shown to be beneficial in experimental hydrocephalus, but the combination of this drug with shunt surgery has not yet been investigated. Fifty-seven-day-old Wistar rats submitted to hydrocephalus by injection of kaolin in the cisterna magna were used and divided into five groups: control (n = 10), hydrocephalic (n = 10), hydrocephalic treated with Edaravone (20 mg/kg/day) (n = 10), hydrocephalic treated with shunt (n = 10) and hydrocephalic treated with shunt and Edaravone (n = 10). Administration of the Edaravone was started 24 h after hydrocephalus induction (P1) and continued until the experimental endpoint (P21). The CSF shunt surgery was performed seven days after hydrocephalus induction (P7). Open-field tests, histological evaluation by hematoxylin and eosin, immunohistochemistry by Caspase-3 and GFAP, and ELISA biochemistry by GFAP were performed. Edaravone reduced reactive astrogliosis in the corpus callosum and germinal matrix (p < 0.05). When used alone or associated with CSF shunt surgery, the drug decreased the cell death process (p < 0.0001) and improved the morphological aspect of the astroglia (p < 0.05). The results showed that Edaravone associated with CSF bypass surgery promotes neuroprotection in young hydrocephalic rats by reducing reactive astrogliosis and decreasing cell death.
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Wang C, Wang X, Tan C, Wang Y, Tang Z, Zhang Z, Liu J, Xiao G. Novel therapeutics for hydrocephalus: Insights from animal models. CNS Neurosci Ther 2021; 27:1012-1022. [PMID: 34151523 PMCID: PMC8339528 DOI: 10.1111/cns.13695] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 05/09/2021] [Accepted: 06/02/2021] [Indexed: 02/06/2023] Open
Abstract
Hydrocephalus is a cerebrospinal fluid physiological disorder that causes ventricular dilation with normal or high intracranial pressure. The current regular treatment for hydrocephalus is cerebrospinal fluid shunting, which is frequently related to failure and complications. Meanwhile, considering that the current nonsurgical treatments of hydrocephalus can only relieve the symptoms but cannot eliminate this complication caused by primary brain injuries, the exploration of more effective therapies has become the focus for many researchers. In this article, the current research status and progress of nonsurgical treatment in animal models of hydrocephalus are reviewed to provide new orientations for animal research and clinical practice.
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Affiliation(s)
- Chuansen Wang
- Department of NeurosurgeryXiangya HospitalCentral South UniversityChangshaHunanChina
- Diagnosis and Treatment Center for HydrocephalusXiangya HospitalCentral South UniversityChangshaHunanChina
- National Clinical Research Center for Geriatric DisordersXiangya HospitalCentral South UniversityChangshaHunanChina
| | - Xiaoqiang Wang
- Department of Pediatric NeurosurgeryXinhua HospitalShanghai Jiaotong University School of MedicineShanghaiChina
| | - Changwu Tan
- Department of NeurosurgeryXiangya HospitalCentral South UniversityChangshaHunanChina
- Diagnosis and Treatment Center for HydrocephalusXiangya HospitalCentral South UniversityChangshaHunanChina
- National Clinical Research Center for Geriatric DisordersXiangya HospitalCentral South UniversityChangshaHunanChina
| | - Yuchang Wang
- Department of NeurosurgeryXiangya HospitalCentral South UniversityChangshaHunanChina
- Diagnosis and Treatment Center for HydrocephalusXiangya HospitalCentral South UniversityChangshaHunanChina
- National Clinical Research Center for Geriatric DisordersXiangya HospitalCentral South UniversityChangshaHunanChina
| | - Zhi Tang
- Department of NeurosurgeryHunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of MedicineCentral South UniversityChangshaHunanChina
| | - Zhiping Zhang
- Department of NeurosurgeryXiangya HospitalCentral South UniversityChangshaHunanChina
- Diagnosis and Treatment Center for HydrocephalusXiangya HospitalCentral South UniversityChangshaHunanChina
- National Clinical Research Center for Geriatric DisordersXiangya HospitalCentral South UniversityChangshaHunanChina
| | - Jingping Liu
- Department of NeurosurgeryXiangya HospitalCentral South UniversityChangshaHunanChina
- Diagnosis and Treatment Center for HydrocephalusXiangya HospitalCentral South UniversityChangshaHunanChina
- National Clinical Research Center for Geriatric DisordersXiangya HospitalCentral South UniversityChangshaHunanChina
| | - Gelei Xiao
- Department of NeurosurgeryXiangya HospitalCentral South UniversityChangshaHunanChina
- Diagnosis and Treatment Center for HydrocephalusXiangya HospitalCentral South UniversityChangshaHunanChina
- National Clinical Research Center for Geriatric DisordersXiangya HospitalCentral South UniversityChangshaHunanChina
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Bassett B, Subramaniyam S, Fan Y, Varney S, Pan H, Carneiro AMD, Chung CY. Minocycline alleviates depression-like symptoms by rescuing decrease in neurogenesis in dorsal hippocampus via blocking microglia activation/phagocytosis. Brain Behav Immun 2021; 91:519-530. [PMID: 33176182 DOI: 10.1016/j.bbi.2020.11.009] [Citation(s) in RCA: 103] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 10/12/2020] [Accepted: 11/05/2020] [Indexed: 12/13/2022] Open
Abstract
Clinical studies examining the potential of anti-inflammatory agents, specifically of minocycline, as a treatment for depression has shown promising results. However, mechanistic insights into the neuroprotective and anti-inflammatory actions of minocycline need to be provided. We evaluated the effect of minocycline on chronic mild stress (CMS) induced depressive-like behavior, and behavioral assays revealed minocycline ameliorate depressive behaviors. Multiple studies suggest a role of microglia in depression, revealing that microglia activation correlates with a decrease in neurogenesis and increased depressive-like behavior. The effect of minocycline on microglia activation in different areas of the dorsal or ventral hippocampus in stressed mice was examined by immunohistochemistry. We observed the increase in the number of activated microglia expressing CD68 after exposure to three weeks of chronic stress, whereas no changes in total microglia number were observed. These changes were observed throughout the DG, CA1 and CA2 regions in dorsal hippocampus but restricted to the DG of the ventral hippocampus. In vitro experiments including western blotting and phagocytosis assay were used to investigate the effect of minocycline on microglia activation. Activation of primary microglia by LPS in vitro causes and ERK1/2 activation, enhancement of iNOS expression and phagocytic activity, and alterations in cellular morphology that are reversed by minocycline exposure, suggesting that minocycline directly acts on microglia to reduce phagocytic potential. Our results suggest the most probable mechanism by which minocycline reverses the pathogenic phagocytic potential of neurotoxic M1 microglia, and reduces the negative phenotypes associated with reduced neurogenesis caused by exposure to chronic stress.
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Affiliation(s)
- Ben Bassett
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA
| | - Selvaraj Subramaniyam
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, China
| | - Yang Fan
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, China
| | - Seth Varney
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA
| | - Hope Pan
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA
| | - Ana M D Carneiro
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA
| | - Chang Y Chung
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA; School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, China; Division of Natural Science, Duke Kunshan University, Kunshan 215316, China.
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Varela MF, Miyabe MM, Oria M. Fetal brain damage in congenital hydrocephalus. Childs Nerv Syst 2020; 36:1661-1668. [PMID: 32451664 DOI: 10.1007/s00381-020-04657-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 04/28/2020] [Indexed: 12/12/2022]
Abstract
BACKGROUND Congenital hydrocephalus (HCP) is a developmental brain disorder characterized by the abnormal accumulation of cerebrospinal fluid within the ventricles. It is caused by genetic and acquired factors that start during early embryogenesis with disruption of the neurogerminal areas. As might be expected, early-onset hydrocephalus alters the process of brain development leading to irreparable neurological deficit. A primary alteration of the ependyma/neural stem cells (affecting vesicle trafficking and abnormal cell junctions) leads to its loss or denudation and translocation of neural progenitor cells (NPCs) and neural stem cells (NSCs) into the cerebrospinal fluid (CSF). Under these abnormal conditions, morphological and functional processes, underlying the concept of astroglial reaction, are initiated in an attempt to recover homeostasis in the periventricular zone. This astroglial reaction includes astrocyte hypertrophy, hyperplasia, and development of a new layer with reorganized functional features that resemble the ependyma. Despite decades of research, there is a lack of information concerning the biological basis of the brain abnormalities that are associated with HCP. DISCUSSION The present review of current literature discusses the neuropathological changes during gestation following the onset of congenital hydrocephalus and the unanswered questions into the pathophysiology of the disease. A better understanding of those missing points might help create novel therapeutic strategies that can reverse or even prevent the ultimate neurological impairment that affects this population and improve long-term clinical outcome.
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Affiliation(s)
- Maria Florencia Varela
- Center for Fetal and Placental Research, Cincinnati Children's Hospital Medical Center (CCHMC), Cincinnati, OH, USA
| | - Marcos M Miyabe
- Center for Fetal and Placental Research, Cincinnati Children's Hospital Medical Center (CCHMC), Cincinnati, OH, USA
| | - Marc Oria
- Center for Fetal and Placental Research, Cincinnati Children's Hospital Medical Center (CCHMC), Cincinnati, OH, USA. .,Department of Pediatrics, College of Medicine, University of Cincinnati, Cincinnati, OH, USA.
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14
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Gu C, Hao X, Li J, Hua Y, Keep RF, Xi G. Effects of minocycline on epiplexus macrophage activation, choroid plexus injury and hydrocephalus development in spontaneous hypertensive rats. J Cereb Blood Flow Metab 2019; 39:1936-1948. [PMID: 30862302 PMCID: PMC6775580 DOI: 10.1177/0271678x19836117] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 01/17/2019] [Accepted: 02/14/2019] [Indexed: 01/11/2023]
Abstract
Hydrocephalus has been reported to occur in spontaneous hypertensive rats (SHRs). The purposes of this study were (1) to use T2 magnetic resonance imaging to examine time of onset, (2) to elucidate potential underlying mechanisms and (3) to determine whether minocycline could prevent hydrocephalus development. Ventriculomegaly was evaluated by T2 imaging in SHRs and Wistar-Kyoto rats from weeks 4 to 7 after birth. Brain histology and transmission electron microscopy were used to assess the periventricular and choroid plexus damage. SHRs were also treated with either vehicle or minocycline. We found that hydrocephalus was observed in SHRs but not in Wistar-Kyoto rats. It occurred at seven weeks of age but was not present at four and five weeks. The hydrocephalus was associated with epiplexus cell (macrophage) activation, choroid plexus cell death and damage to the ventricle wall. Treatment with minocycline from week 5 attenuated hydrocephalus development and pathological changes in choroid plexus and ventricular wall at week 7. The current study found that spontaneous hydrocephalus arises at ∼7 weeks in male SHRs. The early development of hydrocephalus (persistent ventricular dilatation) may result from epiplexus cell activation, choroid plexus cell death and periventricular damage, which can be ameliorated by treatment with minocycline.
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Affiliation(s)
- Chi Gu
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA
- Department of Neurosurgery, the 2 Affiliated Hospital, Zhejiang University, Hangzhou, China
| | - Xiaodi Hao
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA
- Department of Neurology, the 2 Affiliated Hospital, Zhejiang University, Hangzhou, China
| | - Jianru Li
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA
- Department of Neurosurgery, the 2 Affiliated Hospital, Zhejiang University, Hangzhou, China
| | - Ya Hua
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA
| | - Richard F Keep
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA
| | - Guohua Xi
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA
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15
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Zhang L, Hussain Z, Ren Z. Recent Advances in Rational Diagnosis and Treatment of Normal Pressure Hydrocephalus: A Critical Appraisal on Novel Diagnostic, Therapy Monitoring and Treatment Modalities. Curr Drug Targets 2019; 20:1041-1057. [PMID: 30767741 DOI: 10.2174/1389450120666190214121342] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 02/02/2019] [Accepted: 02/06/2019] [Indexed: 12/31/2022]
Abstract
BACKGROUND Normal pressure hydrocephalus (NPH) is a critical brain disorder in which excess Cerebrospinal Fluid (CSF) is accumulated in the brain's ventricles causing damage or disruption of the brain tissues. Amongst various signs and symptoms, difficulty in walking, slurred speech, impaired decision making and critical thinking, and loss of bladder and bowl control are considered the hallmark features of NPH. OBJECTIVE The current review was aimed to present a comprehensive overview and critical appraisal of majorly employed neuroimaging techniques for rational diagnosis and effective monitoring of the effectiveness of the employed therapeutic intervention for NPH. Moreover, a critical overview of recent developments and utilization of pharmacological agents for the treatment of hydrocephalus has also been appraised. RESULTS Considering the complications associated with the shunt-based surgical operations, consistent monitoring of shunting via neuroimaging techniques hold greater clinical significance. Despite having extensive applicability of MRI and CT scan, these conventional neuroimaging techniques are associated with misdiagnosis or several health risks to patients. Recent advances in MRI (i.e., Sagittal-MRI, coronal-MRI, Time-SLIP (time-spatial-labeling-inversion-pulse), PC-MRI and diffusion-tensor-imaging (DTI)) have shown promising applicability in the diagnosis of NPH. Having associated with several adverse effects with surgical interventions, non-invasive approaches (pharmacological agents) have earned greater interest of scientists, medical professional, and healthcare providers. Amongst pharmacological agents, diuretics, isosorbide, osmotic agents, carbonic anhydrase inhibitors, glucocorticoids, NSAIDs, digoxin, and gold-198 have been employed for the management of NPH and prevention of secondary sensory/intellectual complications. CONCLUSION Employment of rational diagnostic tool and therapeutic modalities avoids misleading diagnosis and sophisticated management of hydrocephalus by efficient reduction of Cerebrospinal Fluid (CSF) production, reduction of fibrotic and inflammatory cascades secondary to meningitis and hemorrhage, and protection of brain from further deterioration.
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Affiliation(s)
- Lei Zhang
- Department of Radiology, Baoji Center Hospital, Baoji, Shaanxi, China
| | - Zahid Hussain
- Department of Pharmaceutics, Faculty of Pharmacy, Universiti Teknologi MARA (UiTM) Selangor, Puncak Alam Campus, Bandar Puncak Alam 42300, Selangor, Malaysia
| | - Zhuanqin Ren
- Department of Radiology, Baoji Center Hospital, No. 8 Jiang Tan Road, Baoji 721008, Shaanxi, China
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Koschnitzky JE, Keep RF, Limbrick DD, McAllister JP, Morris JA, Strahle J, Yung YC. Opportunities in posthemorrhagic hydrocephalus research: outcomes of the Hydrocephalus Association Posthemorrhagic Hydrocephalus Workshop. Fluids Barriers CNS 2018; 15:11. [PMID: 29587767 PMCID: PMC5870202 DOI: 10.1186/s12987-018-0096-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 03/09/2018] [Indexed: 12/19/2022] Open
Abstract
The Hydrocephalus Association Posthemorrhagic Hydrocephalus Workshop was held on July 25 and 26, 2016 at the National Institutes of Health. The workshop brought together a diverse group of researchers including pediatric neurosurgeons, neurologists, and neuropsychologists with scientists in the fields of brain injury and development, cerebrospinal and interstitial fluid dynamics, and the blood-brain and blood-CSF barriers. The goals of the workshop were to identify areas of opportunity in posthemorrhagic hydrocephalus research and encourage scientific collaboration across a diverse set of fields. This report details the major themes discussed during the workshop and research opportunities identified for posthemorrhagic hydrocephalus. The primary areas include (1) preventing intraventricular hemorrhage, (2) stopping primary and secondary brain damage, (3) preventing hydrocephalus, (4) repairing brain damage, and (5) improving neurodevelopment outcomes in posthemorrhagic hydrocephalus.
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Affiliation(s)
| | - Richard F. Keep
- University of Michigan, 1500 East Medical Center Drive, Ann Arbor, MI 48109 USA
| | - David D. Limbrick
- Washington University in St. Louis School of Medicine, 660 S. Euclid Ave, St. Louis, MO 63110 USA
| | - James P. McAllister
- Washington University in St. Louis School of Medicine, 660 S. Euclid Ave, St. Louis, MO 63110 USA
| | - Jill A. Morris
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Neuroscience Center, 6001 Executive Blvd, NSC Rm 2112, Bethesda, MD 20892 USA
| | - Jennifer Strahle
- Washington University in St. Louis School of Medicine, 660 S. Euclid Ave, St. Louis, MO 63110 USA
| | - Yun C. Yung
- Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Rd., Building 7, La Jolla, CA 92037 USA
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17
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Todd KL, Brighton T, Norton ES, Schick S, Elkins W, Pletnikova O, Fortinsky RH, Troncoso JC, Molfese PJ, Resnick SM, Conover JC. Ventricular and Periventricular Anomalies in the Aging and Cognitively Impaired Brain. Front Aging Neurosci 2018; 9:445. [PMID: 29379433 PMCID: PMC5771258 DOI: 10.3389/fnagi.2017.00445] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 12/26/2017] [Indexed: 12/14/2022] Open
Abstract
Ventriculomegaly (expansion of the brain’s fluid-filled ventricles), a condition commonly found in the aging brain, results in areas of gliosis where the ependymal cells are replaced with dense astrocytic patches. Loss of ependymal cells would compromise trans-ependymal bulk flow mechanisms required for clearance of proteins and metabolites from the brain parenchyma. However, little is known about the interplay between age-related ventricle expansion, the decline in ependymal integrity, altered periventricular fluid homeostasis, abnormal protein accumulation and cognitive impairment. In collaboration with the Baltimore Longitudinal Study of Aging (BLSA) and Alzheimer’s Disease Neuroimaging Initiative (ADNI), we analyzed longitudinal structural magnetic resonance imaging (MRI) and subject-matched fluid-attenuated inversion recovery (FLAIR) MRI and periventricular biospecimens to map spatiotemporally the progression of ventricle expansion and associated periventricular edema and loss of transependymal exchange functions in healthy aging individuals and those with varying degrees of cognitive impairment. We found that the trajectory of ventricle expansion and periventricular edema progression correlated with degree of cognitive impairment in both speed and severity, and confirmed that areas of expansion showed ventricle surface gliosis accompanied by edema and periventricular accumulation of protein aggregates, suggesting impaired clearance mechanisms in these regions. These findings reveal pathophysiological outcomes associated with normal brain aging and cognitive impairment, and indicate that a multifactorial analysis is best suited to predict and monitor cognitive decline.
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Affiliation(s)
- Krysti L Todd
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, United States
| | - Tessa Brighton
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, United States
| | - Emily S Norton
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, United States
| | - Samuel Schick
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, United States
| | - Wendy Elkins
- Laboratory of Behavioral Neuroscience, Intramural Research Program, National Institute on Aging, Baltimore, MD, United States
| | - Olga Pletnikova
- Department of Pathology, Johns Hopkins School of Medicine, Baltimore, MD, United States
| | - Richard H Fortinsky
- UConn Center on Aging, University of Connecticut School of Medicine, Farmington, CT, United States
| | - Juan C Troncoso
- Department of Pathology, Johns Hopkins School of Medicine, Baltimore, MD, United States
| | - Peter J Molfese
- Department of Psychological Sciences, University of Connecticut, Storrs, CT, United States
| | - Susan M Resnick
- Laboratory of Behavioral Neuroscience, Intramural Research Program, National Institute on Aging, Baltimore, MD, United States
| | - Joanne C Conover
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, United States
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18
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Di Curzio DL, Turner-Brannen E, Mao X, Del Bigio MR. Magnesium sulfate treatment for juvenile ferrets following induction of hydrocephalus with kaolin. Fluids Barriers CNS 2016; 13:7. [PMID: 27121710 PMCID: PMC4848861 DOI: 10.1186/s12987-016-0031-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 04/06/2016] [Indexed: 02/07/2023] Open
Abstract
Background Previous work with 3-week hydrocephalic rats showed that white matter damage could be reduced by the calcium channel antagonist magnesium sulfate (MgSO4). We hypothesized that MgSO4 therapy would improve outcomes in ferrets with hydrocephalus induced with kaolin at 15 days. Methods MRI was performed at 29 days to assess ventricle size and stratify ferrets to treatment conditions. Beginning at 31 days age, they were treated daily for 14 days with MgSO4 (9 mM/kg/day) or sham saline therapy, and then imaged again before sacrifice. Behavior was examined thrice weekly. Histological and biochemical ELISA and myelin enzyme activity assays were performed at 46 days age. Results Hydrocephalic ferrets exhibited some differences in weight and behavior between treatment groups. Those receiving MgSO4 weighed less, were more lethargic, and displayed reduced activity compared to those receiving saline injections. Hydrocephalic ferrets developed ventriculomegaly, which was not modified by MgSO4 treatment. Histological examination showed destruction of periventricular white matter. Glial fibrillary acidic protein content, myelin basic protein content, and myelin enzyme activity did not differ significantly between treatment groups. Conclusion The hydrocephalus-associated disturbances in juvenile ferret brains are not ameliorated by MgSO4 treatment, and lethargy is a significant side effect.
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Affiliation(s)
- Domenico L Di Curzio
- Department of Human Anatomy & Cell Science, University of Manitoba, Winnipeg, MB, Canada.,Children's Hospital Research Institute of Manitoba, Winnipeg, MB, Canada
| | | | - Xiaoyan Mao
- Children's Hospital Research Institute of Manitoba, Winnipeg, MB, Canada
| | - Marc R Del Bigio
- Children's Hospital Research Institute of Manitoba, Winnipeg, MB, Canada. .,Department of Pathology, University of Manitoba Brodie 401-727 McDermot Avenue, Winnipeg, MB, R3E 3P5, Canada.
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Del Bigio MR, Di Curzio DL. Nonsurgical therapy for hydrocephalus: a comprehensive and critical review. Fluids Barriers CNS 2016; 13:3. [PMID: 26846184 PMCID: PMC4743412 DOI: 10.1186/s12987-016-0025-2] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 01/15/2016] [Indexed: 12/13/2022] Open
Abstract
Pharmacological interventions have been tested experimentally and clinically to prevent hydrocephalus and avoid the need for shunting beginning in the 1950s. Clinical trials of varied quality have not demonstrated lasting and convincing protective effects through manipulation of cerebrospinal fluid production, diuresis, blood clot fibrinolysis, or manipulation of fibrosis in the subarachnoid compartment, although there remains some promise in the latter areas. Acetazolamide bolus seems to be useful for predicting shunt response in adults with hydrocephalus. Neuroprotection in the situation of established hydrocephalus has been tested experimentally beginning more recently. Therapies designed to modify blood flow or pulsation, reduce inflammation, reduce oxidative damage, or protect neurons are so far of limited success; more experimental work is needed in these areas. As has been recommended for preclinical studies in stroke and brain trauma, stringent conditions should be met for preclinical studies in hydrocephalus.
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Affiliation(s)
- Marc R Del Bigio
- Department of Pathology, University of Manitoba; Children's Hospital Research Institute of Manitoba, Diagnostic Services Manitoba, 401 Brodie Centre, 715 McDermot Avenue, Winnipeg, MB, R3E 3P5, Canada.
| | - Domenico L Di Curzio
- Department of Human Anatomy and Cell Science, University of Manitoba, Winnipeg, Canada.
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Holmkvist AD, Friberg A, Nilsson UJ, Schouenborg J. Hydrophobic ion pairing of a minocycline/Ca 2+ /AOT complex for preparation of drug-loaded PLGA nanoparticles with improved sustained release. Int J Pharm 2016; 499:351-357. [DOI: 10.1016/j.ijpharm.2016.01.011] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 12/28/2015] [Accepted: 01/05/2016] [Indexed: 01/14/2023]
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21
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McAllister JP, Williams MA, Walker ML, Kestle JRW, Relkin NR, Anderson AM, Gross PH, Browd SR. An update on research priorities in hydrocephalus: overview of the third National Institutes of Health-sponsored symposium "Opportunities for Hydrocephalus Research: Pathways to Better Outcomes". J Neurosurg 2015; 123:1427-38. [PMID: 26090833 DOI: 10.3171/2014.12.jns132352] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Building on previous National Institutes of Health-sponsored symposia on hydrocephalus research, "Opportunities for Hydrocephalus Research: Pathways to Better Outcomes" was held in Seattle, Washington, July 9-11, 2012. Plenary sessions were organized into four major themes, each with two subtopics: Causes of Hydrocephalus (Genetics and Pathophysiological Modifications); Diagnosis of Hydrocephalus (Biomarkers and Neuroimaging); Treatment of Hydrocephalus (Bioengineering Advances and Surgical Treatments); and Outcome in Hydrocephalus (Neuropsychological and Neurological). International experts gave plenary talks, and extensive group discussions were held for each of the major themes. The conference emphasized patient-centered care and translational research, with the main objective to arrive at a consensus on priorities in hydrocephalus that have the potential to impact patient care in the next 5 years. The current state of hydrocephalus research and treatment was presented, and the following priorities for research were recommended for each theme. 1) Causes of Hydrocephalus-CSF absorption, production, and related drug therapies; pathogenesis of human hydrocephalus; improved animal and in vitro models of hydrocephalus; developmental and macromolecular transport mechanisms; biomechanical changes in hydrocephalus; and age-dependent mechanisms in the development of hydrocephalus. 2) Diagnosis of Hydrocephalus-implementation of a standardized set of protocols and a shared repository of technical information; prospective studies of multimodal techniques including MRI and CSF biomarkers to test potential pharmacological treatments; and quantitative and cost-effective CSF assessment techniques. 3) Treatment of Hydrocephalus-improved bioengineering efforts to reduce proximal catheter and overall shunt failure; external or implantable diagnostics and support for the biological infrastructure research that informs these efforts; and evidence-based surgical standardization with longitudinal metrics to validate or refute implemented practices, procedures, or tests. 4) Outcome in Hydrocephalus-development of specific, reliable batteries with metrics focused on the hydrocephalic patient; measurements of neurocognitive outcome and quality-of-life measures that are adaptable, trackable across the growth spectrum, and applicable cross-culturally; development of comparison metrics against normal aging and sensitive screening tools to diagnose idiopathic normal pressure hydrocephalus against appropriate normative age-based data; better understanding of the incidence and prevalence of hydrocephalus within both pediatric and adult populations; and comparisons of aging patterns in adults with hydrocephalus against normal aging patterns.
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Affiliation(s)
- James P McAllister
- Department of Neurosurgery, Division of Pediatric Neurosurgery, Washington University School of Medicine and St. Louis Children's Hospital, St. Louis, Missouri
| | - Michael A Williams
- Department of Neurology, The Sandra and Malcolm Berman Brain & Spine Institute and Adult Hydrocephalus Center, Sinai Hospital, Baltimore, Maryland
| | - Marion L Walker
- Department of Neurosurgery, Division of Pediatric Neurosurgery, University of Utah, Primary Children's Medical Center, Salt Lake City, Utah
| | - John R W Kestle
- Department of Neurosurgery, Division of Pediatric Neurosurgery, University of Utah, Primary Children's Medical Center, Salt Lake City, Utah
| | - Norman R Relkin
- Department of Neurology, Weill Cornell Medical College, New York, New York
| | - Amy M Anderson
- Department of Neurosurgery, Seattle Children's Hospital, Seattle, Washington; and
| | | | - Samuel R Browd
- Departments of Neurosurgery and Bioengineering, University of Washington and Seattle Children's Hospital, Seattle, Washington
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Inhibition of Wnt/β-catenin signal is alleviated reactive gliosis in rats with hydrocephalus. Childs Nerv Syst 2015; 31:227-34. [PMID: 25564198 DOI: 10.1007/s00381-014-2613-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 12/22/2014] [Indexed: 10/24/2022]
Abstract
BACKGROUND Reactive gliosis has been implicated in the pathogenesis of communicating hydrocephalus. Because the activation of Wnt/β-catenin signaling pathway is considered as a significant factor to contribute to brain development, neurodegenerative process, and reactive gliosis, we target this pathway for intervention by using sFRP-l and investigated the expression of β-catenin, cyclin D-1, and glial fibrillary acidic protein (GFAP) in the brain of experimental hydrocephalic rats in terms of protein and gene expression. METHODS Therefore, 30 adult SD rats were randomly divided into the normal group (n = 5), the sham operation group (n = 5), the hydrocephalus group (n = 10), and the sFRP-l group (n = 10). Hydrocephalic rat models were induced by intraventricular injections of 3% kaolin while sFRP-l group was treated by sFRP-l with kaolin injections. The ventricular dilatation was examinated by MRI at 2-week post-operation. After that, β-catenin, cyclin D-1, and GFAP were qualified by Western blot and immunohistochemistry. RESULTS According to the result, the expression of β-catenin and cyclin D-1 increased (P < 0. 05) in the brain tissue of the hydrocephalus group compared with that of the sham group, while GFAP expression in the hydrocephalus group is more obvious (P < 0. 05). In the sFRP-l group, the expression of β-catenin and cyclin D-1 and GFAP expression is lower (P < 0. 05) compared with those of the hydrocephalus group. We demonstrated that the Wnt/β-catenin pathway is activated in the experimental hydrocephalic rat brain. sFRP-l inhibited the expression of β-catenin and cyclin D-1 and alleviated reactive gliosis in the hydrocephalic rat brain tissue, while the development of hydrocephalus was delayed. CONCLUSION These results suggest that regulating Wnt/β-catenin signaling pathway may provide new therapeutic methods for hydrocephalic patients.
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Imaging of spontaneous ventriculomegaly and vascular malformations in Wistar rats: implications for preclinical research. J Neuropathol Exp Neurol 2015; 73:1152-65. [PMID: 25383642 DOI: 10.1097/nen.0000000000000140] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Wistar rats are widely used in biomedical research and commonly serve as a model organism in neuroscience studies. In most cases when noninvasive imaging is not used, studies assume a consistent baseline condition in rats that lack visible differences. While performing a series of traumatic brain injury studies, we discovered mild spontaneous ventriculomegaly in 70 (43.2%) of 162 Wistar rats that had been obtained from 2 different vendors. Advanced magnetic resonance (MR) imaging techniques, including MR angiography and diffusion tensor imaging, were used to evaluate the rats. Multiple neuropathologic abnormalities, including presumed arteriovenous malformations, aneurysms, cysts, white matter lesions, and astrogliosis were found in association with ventriculomegaly. Postmortem microcomputed tomography and immunohistochemical staining confirmed the presence of aneurysms and arteriovenous malformations. Diffusion tensor imaging showed significant decreases in fractional anisotropy and increases in mean diffusivity, axial diffusivity, and radial diffusivity in multiple white matter tracts (p < 0.05). These results could impact the interpretation, for example, of a pseudo-increase of axon integrity and a pseudo-decrease of myelin integrity, based on characteristics intrinsic to rats with ventriculomegaly. We suggest the use of baseline imaging to prevent the inadvertent introduction of a high degree of variability in preclinical studies of neurologic disease or injury in Wistar rats.
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Di Curzio DL, Turner-Brannen E, Del Bigio MR. Oral antioxidant therapy for juvenile rats with kaolin-induced hydrocephalus. Fluids Barriers CNS 2014; 11:23. [PMID: 25324960 PMCID: PMC4199774 DOI: 10.1186/2045-8118-11-23] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 09/23/2014] [Indexed: 12/31/2022] Open
Abstract
Background Oxidative and nitrosylative changes have been shown to occur in conjunction with the hypoxic changes and cellular/axonal damage in hydrocephalic rodent brains. We hypothesized that antioxidant therapy would improve behavioral, neurophysiological, and/or neurobiochemical outcomes in juvenile rats following induction of hydrocephalus. Methods Three-week old rats received an injection of kaolin (aluminum silicate) into the cisterna magna. Magnetic resonance (MR) imaging was performed two weeks later to assess ventricle size and stratify rats to four treatment conditions. Rats were treated for two weeks daily with sham therapy of either oral canola oil or dextrose or experimental therapy of a low or high dose of an antioxidant mixture containing α-tocopherol, L-ascorbic acid, coenzyme Q10 (CoQ10), reduced glutathione, and reduced lipoic acid. Behavior was examined thrice weekly. Results All hydrocephalic groups lagged in weight gain in comparison to non-hydrocephalic controls, all developed significant ventriculomegaly, and all exhibited white matter destruction. Canola oil with or without the antioxidant mixture normalized antioxidant capacity in brain tissue, and the dextrose-treated rats had the greatest ventricular enlargement during the treatment period. However, there were no significant differences between the four treatment groups of hydrocephalic rats for the various behavioral tasks. Glial fibrillary acidic protein and myelin basic protein quantitation showed no differences between the treatment groups or with control rats. There was increased lipid peroxidation in the hydrocephalic rats compared to controls but no differences between treatment groups. Conclusion The antioxidant cocktail showed no therapeutic benefits for juvenile rats with kaolin-induced hydrocephalus although canola oil might have mild benefit.
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Affiliation(s)
- Domenico L Di Curzio
- Departments of Human Anatomy & Cell Science, 715 McDermot Avenue, Winnipeg, MB R3E 3P4, Canada ; Manitoba Institute of Child Health, 715 McDermot Avenue, Winnipeg, MB R3E 3P4, Canada
| | - Emily Turner-Brannen
- Manitoba Institute of Child Health, 715 McDermot Avenue, Winnipeg, MB R3E 3P4, Canada
| | - Marc R Del Bigio
- Manitoba Institute of Child Health, 715 McDermot Avenue, Winnipeg, MB R3E 3P4, Canada ; Department of Pathology, University of Manitoba, 727 McDermot Avenue, Winnipeg, R3E 3P5, Canada
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Shim JW, Sandlund J, Madsen JR. VEGF: a potential target for hydrocephalus. Cell Tissue Res 2014; 358:667-83. [PMID: 25146955 DOI: 10.1007/s00441-014-1978-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 07/28/2014] [Indexed: 12/13/2022]
Abstract
Growth factors are primarily responsible for the genesis, differentiation and proliferation of cells and maintenance of tissues. Given the central role of growth factors in signaling between cells in health and in disease, it is understandable that disruption of growth factor-mediated molecular signaling can cause diverse phenotypic consequences including cancer and neurological conditions. This review will focus on the specific questions of enlarged cerebral ventricles and hydrocephalus. It is also well known that angiogenic factors, such as vascular endothelial growth factor (VEGF), affect tissue permeability through activation of receptors and adhesion molecules; hence, recent studies showing elevations of this factor in pediatric hydrocephalus led to the demonstration that VEGF can induce ventriculomegaly and altered ependyma when infused in animals. In this review, we discuss recent findings implicating the involvement of biochemical and biophysical factors that can induce a VEGF-mimicking effect in communicating hydrocephalus and pay particular attention to the role of the VEGF system as a potential pharmacological target in the treatment of some cases of hydrocephalus. The source of VEGF secretion in the cerebral ventricles, in periventricular regions and during pathologic events including hydrocephalus following hypoxia and hemorrhage is sought. The review is concluded with a summary of potential non-surgical treatments in preclinical studies suggesting several molecular targets including VEGF for hydrocephalus and related neurological disorders.
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Affiliation(s)
- Joon W Shim
- Department of Biology, Indiana University-Purdue University Indianapolis, 723 W. Michigan Street SL354, Indianapolis, IN, 46202, USA
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Drabek T, Janata A, Wilson CD, Stezoski J, Janesko-Feldman K, Tisherman SA, Foley LM, Verrier J, Kochanek PM. Minocycline attenuates brain tissue levels of TNF-α produced by neurons after prolonged hypothermic cardiac arrest in rats. Resuscitation 2014; 85:284-91. [PMID: 24513126 PMCID: PMC3952024 DOI: 10.1016/j.resuscitation.2013.10.015] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Revised: 09/24/2013] [Accepted: 10/15/2013] [Indexed: 12/14/2022]
Abstract
Neuro-cognitive disabilities are a well-recognized complication of hypothermic circulatory arrest. We and others have reported that prolonged cardiac arrest (CA) produces neuronal death and microglial proliferation and activation that are only partially mitigated by hypothermia. Microglia, and possibly other cells, are suggested to elaborate tumor necrosis factor alpha (TNF-α), which can trigger neuronal death cascades and exacerbate edema after CNS insults. Minocycline is neuroprotective in some brain ischemia models in part by blunting the microglial response. We tested the hypothesis that minocycline would attenuate neuroinflammation as reflected by brain tissue levels of TNF-α after hypothermic CA in rats. Rats were subjected to rapid exsanguination, followed by a 6 min normothermic CA. Hypothermia (30 °C) was then induced by an aortic saline flush. After a total of 20 min CA, resuscitation was achieved via cardiopulmonary bypass (CPB). After 5 min reperfusion, minocycline (90 mg kg−1; n = 6) or vehicle (PBS; n = 6) was given. Hypothermia (34 °C) was maintained for 6 h. Rats were sacrificed at 6 or 24 h. TNF-α was quantified (ELISA) in four brain regions (cerebellum, CEREB; cortex, CTX; hippocampus, HIP; striatum, STRI). Naïve rats (n = 6) and rats subjected to the same anesthesia and CPB but no CA served as controls (n = 6). Immunocytochemistry was used to localize TNF-α. Naïve rats and CPB controls had no detectable TNF-α in any brain region. CA markedly increased brain TNF-α. Regional differences were seen, with the highest TNF-α levels in striatum in CA groups (10-fold higher, P < 0.05 vs. all other brain regions). TNF-α was undetectable at 24 h. Minocycline attenuated TNF-α levels in CTX, HIP and STRI (P < 0.05). TNF-α showed unique co-localization with neurons. In conclusion, we report region-dependent early increases in brain TNF-α levels after prolonged hypothermic CA, with maximal increases in striatum. Surprisingly, TNF-α co-localized in neurons and not microglia. Minocycline attenuated TNF-α by approximately 50% but did not totally ablate its production. That minocycline decreased brain TNF-α levels suggests that it may represent a therapeutic adjunct to hypothermia in CA neuroprotection. University of Pittsburgh IACUC 0809278B-3.
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Affiliation(s)
- Tomas Drabek
- Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Anesthesiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Andreas Janata
- Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Caleb D. Wilson
- Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Jason Stezoski
- Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Anesthesiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Keri Janesko-Feldman
- Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Samuel A. Tisherman
- Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Lesley M. Foley
- Pittsburgh NMR Center for Biomedical Research, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
| | - Jonathan Verrier
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Patrick M. Kochanek
- Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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Ming Z, Criswell HE, Breese GR. Evidence for TNFα action on excitatory and inhibitory neurotransmission in the central amygdala: a brain site influenced by stress. Brain Behav Immun 2013; 33:102-11. [PMID: 23770090 PMCID: PMC3775850 DOI: 10.1016/j.bbi.2013.06.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Revised: 05/29/2013] [Accepted: 06/01/2013] [Indexed: 12/12/2022] Open
Abstract
Anxiety-like responses to stress are accompanied by elevation of brain cytokine-mRNAs. Because cytokines microinjected into central-amygdala (CeA) substitute for stress in a behavioral paradigm, the possibility was raised that cytokines increased by stress influence behavior by affecting CeA-neural activity. Previously, cytokines increased firing-rate of CeA-neurons comparable to that induced by corticotropin-releasing factor (CRF). In this investigation, tumor-necrosis-factor-α (TNFα) increased amplitude, but not frequency of mEPSCs from CeA-neurons. Additionally, TNFα decreased the threshold for triggering action potentials from CeA-neurons without altering membrane-properties during current-clamp recording. Glutamate-receptor-antagonist blockade of mEPSCs and the TNFα-induced reduction in firing threshold implicated glutamate in these changes. A phosphatidyl-inositol-3-kinase-antagonist prevented the TNFα-induced increased in amplitude of mEPSCs, documenting a TNFα intracellular influence. Additionally, TNFα increased frequency, but not amplitude of mIPSCs. CRF-receptor-antagonists were found to prevent the TNFα-induced increase in mIPSC-frequency, without altering the TNFα-induced amplitude increase in mEPSCs or the reduced threshold for action-potentials by TNFα. To clarify how TNFα was increasing CRF-release in the presence of tetrodotoxin, the possibility tested was whether preventing glial-activation would prevent this elevated mIPSC-frequency blocked by CRF-receptor antagonists. Minocycline, which blocks glial activation, prevented the TNFα-induced increase in mIPSC-frequency - a finding consistent with glia contributing to the CRF-involvement in this TNFα action. To fully understand the means by which a CRF1-receptor-antagonist and minocycline prevent TNFα from increasing mIPSC-frequency will require further clarification. Nonetheless, these data provide convincing evidence that release of TNFα by stress could alter neural activity of CeA-neurons by influencing GABA-and glutamate function.
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Affiliation(s)
- Zhen Ming
- Bowles Center for Alcohol Studies, The University of North Carolina at Chapel Hill, Chapel Hill, NC USA
| | - Hugh E. Criswell
- Bowles Center for Alcohol Studies, The University of North Carolina at Chapel Hill, Chapel Hill, NC USA
| | - George R. Breese
- Bowles Center for Alcohol Studies, The University of North Carolina at Chapel Hill, Chapel Hill, NC USA
- Department of Psychiatry, The University of North Carolina at Chapel Hill, Chapel Hill, NC USA
- Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, NC USA
- UNC Neuroscience Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC USA
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Lee L. Riding the wave of ependymal cilia: genetic susceptibility to hydrocephalus in primary ciliary dyskinesia. J Neurosci Res 2013; 91:1117-32. [PMID: 23686703 DOI: 10.1002/jnr.23238] [Citation(s) in RCA: 105] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Revised: 03/22/2013] [Accepted: 03/20/2013] [Indexed: 12/17/2022]
Abstract
Congenital hydrocephalus is a relatively common and debilitating birth defect with several known physiological causes. Dysfunction of motile cilia on the ependymal cells that line the ventricular surface of the brain can result in hydrocephalus by hindering the proper flow of cerebrospinal fluid. As a result, hydrocephalus can be associated with primary ciliary dyskinesia, a rare pediatric syndrome resulting from defects in ciliary and flagellar motility. Although the prevalence of hydrocephalus in primary ciliary dyskinesia patients is low, it is a common hallmark of the disease in mouse models, suggesting that distinct genetic mechanisms underlie the differences in the development and physiology of human and mouse brains. Mouse models of primary ciliary dyskinesia reveal strain-specific differences in the appearance and severity of hydrocephalus, indicating the presence of genetic modifiers segregating in inbred strains. These models may provide valuable insight into the genetic mechanisms that regulate susceptibility to hydrocephalus under the conditions of ependymal ciliary dysfunction.
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Affiliation(s)
- Lance Lee
- Sanford Children's Health Research Center, Sanford Research USD, Sioux Falls, South Dakota, USA.
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29
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Karperien A, Ahammer H, Jelinek HF. Quantitating the subtleties of microglial morphology with fractal analysis. Front Cell Neurosci 2013; 7:3. [PMID: 23386810 PMCID: PMC3558688 DOI: 10.3389/fncel.2013.00003] [Citation(s) in RCA: 320] [Impact Index Per Article: 29.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Accepted: 01/08/2013] [Indexed: 01/17/2023] Open
Abstract
It is well established that microglial form and function are inextricably linked. In recent years, the traditional view that microglial form ranges between “ramified resting” and “activated amoeboid” has been emphasized through advancing imaging techniques that point to microglial form being highly dynamic even within the currently accepted morphological categories. Moreover, microglia adopt meaningful intermediate forms between categories, with considerable crossover in function and varying morphologies as they cycle, migrate, wave, phagocytose, and extend and retract fine and gross processes. From a quantitative perspective, it is problematic to measure such variability using traditional methods, but one way of quantitating such detail is through fractal analysis. The techniques of fractal analysis have been used for quantitating microglial morphology, to categorize gross differences but also to differentiate subtle differences (e.g., amongst ramified cells). Multifractal analysis in particular is one technique of fractal analysis that may be useful for identifying intermediate forms. Here we review current trends and methods of fractal analysis, focusing on box counting analysis, including lacunarity and multifractal analysis, as applied to microglial morphology.
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Affiliation(s)
- Audrey Karperien
- Centre for Research in Complex Systems, School of Community Health, Charles Sturt University Albury, NSW, Australia
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Xu H, Tan G, Zhang S, Zhu H, Liu F, Huang C, Zhang F, Wang Z. Minocycline reduces reactive gliosis in the rat model of hydrocephalus. BMC Neurosci 2012; 13:148. [PMID: 23217034 PMCID: PMC3529686 DOI: 10.1186/1471-2202-13-148] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Accepted: 11/23/2012] [Indexed: 11/16/2022] Open
Abstract
Background Reactive gliosis had been implicated in injury and recovery patterns associated with hydrocephalus. Our aim is to determine the efficacy of minocycline, an antibiotic known for its anti-inflammatory properties, to reduce reactive gliosis and inhibit the development of hydrocephalus. Results The ventricular dilatation were evaluated by MRI at 1-week post drugs treated, while GFAP and Iba-1were detected by RT-PCR, Immunohistochemistry and Western blot. The expression of GFAP and Iba-1 was significantly higher in hydrocephalic group compared with saline control group (p < 0.05). Minocycline treatment of hydrocephalic animals reduced the expression of GFAP and Iba-1 significantly (p < 0.05). Likewise, the severity of ventricular dilatation is lower in minocycline treated hydrocephalic animals compared with the no minocycline group (p < 0.05). Conclusion Minocycline treatment is effective in reducing the gliosis and delaying the development of hydrocephalus with prospective to be the auxiliary therapeutic method of hydrocephalus.
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Affiliation(s)
- Hao Xu
- Department of Neurosurgery, First Affiliate Hospital of Xiamen University, Xiamen, Fujian Province 361003, China
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Roales-Buján R, Páez P, Guerra M, Rodríguez S, Vío K, Ho-Plagaro A, García-Bonilla M, Rodríguez-Pérez LM, Domínguez-Pinos MD, Rodríguez EM, Pérez-Fígares JM, Jiménez AJ. Astrocytes acquire morphological and functional characteristics of ependymal cells following disruption of ependyma in hydrocephalus. Acta Neuropathol 2012; 124:531-46. [PMID: 22576081 PMCID: PMC3444707 DOI: 10.1007/s00401-012-0992-6] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Revised: 04/25/2012] [Accepted: 04/27/2012] [Indexed: 01/10/2023]
Abstract
Hydrocephalic hyh mutant mice undergo a programmed loss of the neuroepithelium/ependyma followed by a reaction of periventricular astrocytes, which form a new cell layer covering the denuded ventricular surface. We present a comparative morphological and functional study of the newly formed layer of astrocytes and the multiciliated ependyma of hyh mice. Transmission electron microscopy, immunocytochemistry for junction proteins (N-cadherin, connexin 43) and proteins involved in permeability (aquaporin 4) and endocytosis (caveolin-1, EEA1) were used. Horseradish peroxidase (HRP) and lanthanum nitrate were used to trace the intracellular and paracellular transport routes. The astrocyte layer shares several cytological features with the normal multiciliated ependyma, such as numerous microvilli projected into the ventricle, extensive cell–cell interdigitations and connexin 43-based gap junctions, suggesting that these astrocytes are coupled to play an unknown function as a cell layer. The ependyma and the astrocyte layers also share transport properties: (1) high expression of aquaporin 4, caveolin-1 and the endosome marker EEA1; (2) internalization into endocytic vesicles and early endosomes of HRP injected into the ventricle; (3) and a similar paracellular route of molecules moving between CSF, the subependymal neuropile and the pericapillary space, as shown by lanthanum nitrate and HRP. A parallel analysis performed in human hydrocephalic foetuses indicated that a similar phenomenon would occur in humans. We suggest that in foetal-onset hydrocephalus, the astrocyte assembly at the denuded ventricular walls functions as a CSF–brain barrier involved in water and solute transport, thus contributing to re-establish lost functions at the brain parenchyma–CSF interphase.
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Affiliation(s)
- Ruth Roales-Buján
- Departamento de Biología Celular, Genética y Fisiología, Universidad de Málaga, Campus Universitario de Teatinos, 29071 Málaga, Spain
| | - Patricia Páez
- Departamento de Biología Celular, Genética y Fisiología, Universidad de Málaga, Campus Universitario de Teatinos, 29071 Málaga, Spain
| | - Montserrat Guerra
- Instituto de Anatomía, Histología y Patología, Facultad de Medicina, Universidad Austral de Chile, Valdivia, Chile
| | - Sara Rodríguez
- Instituto de Anatomía, Histología y Patología, Facultad de Medicina, Universidad Austral de Chile, Valdivia, Chile
| | - Karin Vío
- Instituto de Anatomía, Histología y Patología, Facultad de Medicina, Universidad Austral de Chile, Valdivia, Chile
| | - Ailec Ho-Plagaro
- Departamento de Biología Celular, Genética y Fisiología, Universidad de Málaga, Campus Universitario de Teatinos, 29071 Málaga, Spain
| | - María García-Bonilla
- Departamento de Biología Celular, Genética y Fisiología, Universidad de Málaga, Campus Universitario de Teatinos, 29071 Málaga, Spain
| | - Luis-Manuel Rodríguez-Pérez
- Departamento de Biología Celular, Genética y Fisiología, Universidad de Málaga, Campus Universitario de Teatinos, 29071 Málaga, Spain
| | - María-Dolores Domínguez-Pinos
- Departamento de Biología Celular, Genética y Fisiología, Universidad de Málaga, Campus Universitario de Teatinos, 29071 Málaga, Spain
| | - Esteban-Martín Rodríguez
- Instituto de Anatomía, Histología y Patología, Facultad de Medicina, Universidad Austral de Chile, Valdivia, Chile
| | - José-Manuel Pérez-Fígares
- Departamento de Biología Celular, Genética y Fisiología, Universidad de Málaga, Campus Universitario de Teatinos, 29071 Málaga, Spain
| | - Antonio-Jesús Jiménez
- Departamento de Biología Celular, Genética y Fisiología, Universidad de Málaga, Campus Universitario de Teatinos, 29071 Málaga, Spain
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Reactive gliosis and neuroinflammation in rats with communicating hydrocephalus. Neuroscience 2012; 218:317-25. [DOI: 10.1016/j.neuroscience.2012.05.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2012] [Revised: 04/05/2012] [Accepted: 05/03/2012] [Indexed: 02/07/2023]
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Eskandari R, Harris CA, McAllister JP. Reactive astrocytosis in feline neonatal hydrocephalus: acute, chronic, and shunt-induced changes. Childs Nerv Syst 2011; 27:2067-76. [PMID: 21847645 DOI: 10.1007/s00381-011-1552-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Accepted: 07/29/2011] [Indexed: 10/17/2022]
Abstract
PURPOSE Reactive astrocytosis has been implicated in injury and recovery patterns associated with hydrocephalus. To investigate temporal changes in astrogliosis during the early progression of hydrocephalus, after shunting, and after long-term ventriculomegaly, glial fibrillary protein (GFAP) levels were analyzed in a feline model. METHODS Obstructive hydrocephalus was induced in 10-day-old kittens by intracisternal injections of 25% kaolin. Acute non-shunted animals were killed 15 days post-kaolin injection to represent the pre-shunt condition. Shunt-treated animals received ventriculoperitoneal shunts 15 days post-injection and were killed 10 or 60 days later to represent short- and long-term recovery periods. Chronic untreated animals had Ommaya reservoirs implanted 15 days post-kaolin, which were tapped intermittently until they were killed 60 days later. Ventriculomegaly was monitored by neuroimaging before and after shunting and at death. RNA and total protein from primary visual cortex were analyzed by Northern and Western blotting. RESULTS GFAP RNA and protein levels for acute and chronic non-shunted hydrocephalic animals were 77% and 247% (p < 0.01) and 659% (p < 0.05) and 871% (p < 0.05) higher than controls, respectively. Shunted animals with short-term recovery demonstrated a mismatch in GFAP levels, with RNA expression decreasing 26% and protein increasing 335% (p < 0.01). Shunted animals with a long-term recovery exhibited GFAP RNA and protein levels 201% and 357% above normal, respectively. CONCLUSIONS These results indicate that a reactive astrocytic response continues to rise dramatically in chronic hydrocephalus, suggesting ongoing gliosis and potential damage. Shunting partially ameliorates the continuation of astrogliosis, but does not completely reverse this inflammatory reaction even after a long recovery.
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Affiliation(s)
- Ramin Eskandari
- Division of Pediatric Neurosurgery, Department of Neurosurgery, University of Utah, 175 North Medical Drive, Salt Lake City, UT 84132, USA
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Yamada J, Jinno S. Alterations in neuronal survival and glial reactions after axotomy by ceftriaxone and minocycline in the mouse hypoglossal nucleus. Neurosci Lett 2011; 504:295-300. [PMID: 21970974 DOI: 10.1016/j.neulet.2011.09.051] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2011] [Revised: 08/26/2011] [Accepted: 09/19/2011] [Indexed: 10/17/2022]
Abstract
Some antibiotics are suggested to exert neuroprotective effects via regulation of glial responses. Attenuation of microglial activation by minocycline prevents neuronal death in a variety of experimental models for neurological diseases, such as cerebral ischemia, Parkinson's and Huntington's disease. Ceftriaxone delays loss of neurons in genetic animal models of amyotrophic lateral sclerosis through upregulation of astrocytic glutamate transporter expression (GLT-1). However, it remains largely unknown whether these antibiotics are able to protect neurons in axotomy models for progressive motor neuron diseases. Recent studies have shown that the axotomized motoneurons of the adult rat can survive, whereas those of the adult mouse undergo neuronal degeneration. We thus examined the possible effects of ceftriaxone and minocycline on neuronal loss and glial reactions in the mouse hypoglossal nucleus after axotomy. The survival rate of lesioned motoneurons at 28 days after axotomy (D28) was significantly improved by ceftriaxone and minocycline treatment. There were no significant differences in the cellular densities of astrocytes between ceftriaxone-treated and saline-treated animals. Ceftriaxone administration increased the expression of GLT-1 in the hypoglossal nucleus, while it suppressed the reactive increase of glial fibrillary acidic protein (GFAP) expression to control level. The cellular densities of microglia at D28 were significantly lower in minocycline-treated mice than in saline-treated mice. The time course analysis showed that immediate increase in microglia at D3 and D7 was not suppressed by minocycline. The present observations show that minocycline and ceftriaxone promote survival of lesioned motoneurons in the mouse hypoglossal nucleus, and also suggest that alterations in glial responses might be involved in neuroprotective actions of antibiotics.
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Affiliation(s)
- Jun Yamada
- Department of Anatomy and Neurobiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Fukuoka 812-8582, Japan
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Shahzad K, Thati M, Wang H, Kashif M, Wolter J, Ranjan S, He T, Zhou Q, Blessing E, Bierhaus A, Nawroth PP, Isermann B. Minocycline reduces plaque size in diet induced atherosclerosis via p27(Kip1). Atherosclerosis 2011; 219:74-83. [PMID: 21719015 DOI: 10.1016/j.atherosclerosis.2011.05.041] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2011] [Revised: 05/23/2011] [Accepted: 05/26/2011] [Indexed: 12/01/2022]
Abstract
OBJECTIVE Minocycline, a tetracycline derivate, mediates vasculoprotective effects independent of its antimicrobial properties. Thus, minocycline protects against diabetic nephropathy and reduces neointima formation following vascular injury through inhibition of apoptosis or migration, respectively. Whether minocycline has an effect on primary atherogenesis remains unknown. METHODS Using morphological and immunohistochemical analyses we determined de novo atherogenesis in ApoE-/- mice receiving a high fat diet (HFD) with or without minocycline treatment. The effect of minocycline on proliferation, expression of p27(Kip1) or PARP-1 (Poly [ADP-ribose] polymerase 1), or on PAR (poly ADP-ribosylation) modification in vascular smooth muscle cells (VSMC) was analyzed in ex vivo and in vitro (primary human and mouse VSMC). RESULTS AND CONCLUSION Minocycline reduced plaque size and stenosis in ApoE-/- HFD mice. This was associated with a lower number and less proliferation of VSMC, reduced PAR (poly ADP-ribosylation) modification and increased p27(Kip1) expression within the plaques. In agreement with the ex vivo data minocycline reduced proliferation, PARP-1 expression, PAR modification while inducing p27 expression in human and mouse VSMC in vitro. These effects were observed at a low minocycline concentration (10 μM), which had no effect on VSMC migration or apoptosis. Minocycline inhibited PARP-1 and induced p27(Kip1) expression in VSMC as efficiently as the specific PARP-1 inhibitor PJ 34. Knock down of p27(Kip1) abolished the antiproliferative effect of minocycline. These data establish a novel antiatherosclerotic mechanism of minocycline during de novo atherogenesis, which depends on p27(Kip1) mediated inhibition of VSMC proliferation.
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Affiliation(s)
- Khurrum Shahzad
- Internal Medicine I and Clinical Chemistry, University of Heidelberg, INF 410, 69120 Heidelberg, Germany
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Deren KE, Packer M, Forsyth J, Milash B, Abdullah OM, Hsu EW, McAllister JP. Reactive astrocytosis, microgliosis and inflammation in rats with neonatal hydrocephalus. Exp Neurol 2010; 226:110-9. [PMID: 20713048 DOI: 10.1016/j.expneurol.2010.08.010] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2010] [Revised: 07/30/2010] [Accepted: 08/07/2010] [Indexed: 11/15/2022]
Abstract
The deleterious effects of hydrocephalus, a disorder that primarily affects children, include reactive astrocytosis, microgliosis and inflammatory responses; however, the roles that these mechanisms play in the pathophysiology of hydrocephalus are still not clear in terms of cytopathology and gene expression. Therefore we have examined neuroinflammation at both the cellular and the molecular levels in an experimental model of neonatal obstructive hydrocephalus. On post-natal day 1, rats received an intracisternal injection of kaolin to induce hydrocephalus; control animals received saline injections. Prior to sacrifice on post-natal day 22, animals underwent magnetic resonance imaging to quantify ventricular enlargement, and the parietal cortex was harvested for analysis. Immunohistochemistry and light microscopy were performed on 5 hydrocephalic and 5 control animals; another set of 5 hydrocephalic and 5 control animals underwent molecular testing with Western blots and a gene microarray. Scoring of immunoreactivity on a 4-point ranking scale for GFAP and Iba-1 demonstrated an increase in reactive astrocytes and reactive microglia respectively in the hydrocephalic animals compared to controls (2.90±0.11 vs. 0.28±0.26; 2.91±0.11 vs. 0.58±0.23, respectively). Western blots confirmed these results. Microarray analysis identified significant (1.5-fold) changes in 1729 of 33,951 genes, including 26 genes out of 185 genes (26/185) in the cytokine-cytokine receptor interaction pathway, antigen processing and presentation pathways (15/66), and the apoptosis pathway (10/69). Collectively, these results demonstrate alterations in normal physiology and an up-regulation of the inflammatory response. These findings lead to a better understanding of neonatal hydrocephalus and begin to form a baseline for future treatments that may reverse these effects.
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Affiliation(s)
- Kelley E Deren
- Department of Neurosurgery, Division of Pediatric Neurosurgery, Primary Children's Medical Center, and The University of Utah, 175 N. Medical Drive East, Salt Lake City, UT 84132, USA.
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