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Israelsen IME, Kamp-Jensen C, Westgate CSJ, Styrishave B, Jensen RH, Eftekhari S. Cycle-dependent sex differences in expression of membrane proteins involved in cerebrospinal fluid secretion at rat choroid plexus. BMC Neurosci 2023; 24:60. [PMID: 37946101 PMCID: PMC10633912 DOI: 10.1186/s12868-023-00829-w] [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: 06/15/2023] [Accepted: 10/20/2023] [Indexed: 11/12/2023] Open
Abstract
BACKGROUND Female sex is a known risk factor of brain disorders with raised intracranial pressure (ICP) and sex hormones have been suggested to alter cerebrospinal fluid (CSF) dynamics, thus impairing ICP regulation in CSF disorders such as idiopathic intracranial hypertension (IIH). The choroid plexus (CP) is the tissue producing CSF and it has been hypothesized that altered hormonal composition could affect the activity of transporters involved in CSF secretion, thus affecting ICP. Therefore, we aimed to investigate if expression of various transporters involved in CSF secretion at CP were different between males and females and between females in different estrous cycle states. Steroid levels in serum was also investigated. METHODS Female and male rats were used to determine sex-differences in the genes encoding for the transporters Aqp1 and 4, NKCC1, NBCe2, NCBE; carbonic anhydrase enzymes II and III (CA), subunits of the Na+/K+-ATPase including Atp1a1, Atp1b1 and Fxyd1 at CP. The estrous cycle stage metestrus (MET) and estrous (ES) were determined before euthanasia. Serum and CP were collected and subjected to RT-qPCR analysis and western blots. Serum was used to measure steroid levels using liquid chromatography tandem mass spectrometry (LC-MS/MS). RESULTS Significant differences in gene expression and steroid levels between males and ES females were found, while no differences were found between male and MET females. During ES, expression of Aqp1 was lower (p < 0.01) and NKCC1 was higher in females compared to males. CAII was lower while CAIII was higher in ES females (p < 0.0001). Gene expression of Atp1a1 was lower in ES compared to male (p = 0.0008). Several of these choroidal genes were also significantly different in MET compared to females in ES. Differences in gene expression during the estrus cycle were correlated to serum level of steroid hormones. Protein expression of AQP1 (p = 0.008) and CAII (p = 0.035) was reduced in ES females compared to males. CONCLUSIONS This study demonstrates for the first time that expression at CP is sex-dependent and markedly affected by the estrous cycle in female rats. Further, expression was related to hormone levels in serum. This opens a completely new avenue for steroid regulation of the expression of CSF transporters and the close link to the understanding of CSF disorders such as IIH.
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Affiliation(s)
- Ida Marchen Egerod Israelsen
- Danish Headache Center, Department of Neurology, Glostrup Research Institute, Rigshospitalet-Glostrup, University of Copenhagen, Nordstjernevej 42, 2600, Glostrup, Denmark
| | - Christina Kamp-Jensen
- Danish Headache Center, Department of Neurology, Glostrup Research Institute, Rigshospitalet-Glostrup, University of Copenhagen, Nordstjernevej 42, 2600, Glostrup, Denmark
| | - Connar Stanley James Westgate
- Danish Headache Center, Department of Neurology, Glostrup Research Institute, Rigshospitalet-Glostrup, University of Copenhagen, Nordstjernevej 42, 2600, Glostrup, Denmark
| | - Bjarne Styrishave
- Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Rigmor H Jensen
- Danish Headache Center, Department of Neurology, Glostrup Research Institute, Rigshospitalet-Glostrup, University of Copenhagen, Nordstjernevej 42, 2600, Glostrup, Denmark
| | - Sajedeh Eftekhari
- Danish Headache Center, Department of Neurology, Glostrup Research Institute, Rigshospitalet-Glostrup, University of Copenhagen, Nordstjernevej 42, 2600, Glostrup, Denmark.
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Carmona-Calero EM, González-Toledo JM, Hernández-Abad LG, Castañeyra-Perdomo A, González-Marrero I. Early Regressive Development of the Subcommissural Organ of Two Human Fetuses with Non-Communicating Hydrocephalus. CHILDREN (BASEL, SWITZERLAND) 2022; 9:children9121966. [PMID: 36553409 PMCID: PMC9776597 DOI: 10.3390/children9121966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 12/07/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022]
Abstract
Hydrocephalus is a central nervous system condition characterized by CSF buildup and ventricular hypertrophy. It is divided into two types: communicative and non-communicating hydrocephalus. Congenital hydrocephalus has been linked to several changes in the subcommissural organ (SCO). However, it is unclear whether these changes occur before or as a result of the hydrocephalic illness. This report presents three cases of human fetuses with hydrocephalus: one non-communicating case, two communicating cases, and two controls. Hematoxylin-Eosin (H&E) or cresyl violet and immunohistochemistry with anti-transthyretin were used to analyze SCO morphological and secretory changes. We conclude that in the cases presented here, there could be an early regression in the SCO of the communicating cases that is not present in the non-communicating case.
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Affiliation(s)
- Emilia M. Carmona-Calero
- Departamento de Ciencias Médicas Básicas, Facultad de Ciencias de la Salud, Campus de Ofra, Universidad de La Laguna, 38320 Santa Cruz de Tenerife, Spain
- Instituto de Investigación y Ciencias Puerto del Rosario, 35600 Las Palmas de Gran Canaria, Spain
| | - Juan M. González-Toledo
- Departamento de Ciencias Médicas Básicas, Facultad de Ciencias de la Salud, Campus de Ofra, Universidad de La Laguna, 38320 Santa Cruz de Tenerife, Spain
| | - Luis G. Hernández-Abad
- Departamento de Ciencias Médicas Básicas, Facultad de Ciencias de la Salud, Campus de Ofra, Universidad de La Laguna, 38320 Santa Cruz de Tenerife, Spain
| | - Agustin Castañeyra-Perdomo
- Departamento de Ciencias Médicas Básicas, Facultad de Ciencias de la Salud, Campus de Ofra, Universidad de La Laguna, 38320 Santa Cruz de Tenerife, Spain
- Instituto de Investigación y Ciencias Puerto del Rosario, 35600 Las Palmas de Gran Canaria, Spain
- Correspondence:
| | - Ibrahim González-Marrero
- Departamento de Ciencias Médicas Básicas, Facultad de Ciencias de la Salud, Campus de Ofra, Universidad de La Laguna, 38320 Santa Cruz de Tenerife, Spain
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Altered Expression of AQP1 and AQP4 in Brain Barriers and Cerebrospinal Fluid May Affect Cerebral Water Balance during Chronic Hypertension. Int J Mol Sci 2022; 23:ijms232012277. [PMID: 36293145 PMCID: PMC9603298 DOI: 10.3390/ijms232012277] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 10/03/2022] [Accepted: 10/11/2022] [Indexed: 11/07/2022] Open
Abstract
Hypertension is the leading cause of cardiovascular affection and premature death worldwide. The spontaneously hypertensive rat (SHR) is the most common animal model of hypertension, which is characterized by secondary ventricular dilation and hydrocephalus. Aquaporin (AQP) 1 and 4 are the main water channels responsible for the brain’s water balance. The present study focuses on defining the expression of AQPs through the time course of the development of spontaneous chronic hypertension. We performed immunofluorescence and ELISA to examine brain AQPs from 10 SHR, and 10 Wistar−Kyoto (WKY) rats studied at 6 and 12 months old. There was a significant decrease in AQP1 in the choroid plexus of the SHR-12-months group compared with the age-matched control (p < 0.05). In the ependyma, AQP4 was significantly decreased only in the SHR-12-months group compared with the control or SHR-6-months groups (p < 0.05). Per contra, AQP4 increased in astrocytes end-feet of 6 months and 12 months SHR rats (p < 0.05). CSF AQP detection was higher in the SHR-12-months group than in the age-matched control group. CSF findings were confirmed by Western blot. In SHR, ependymal and choroidal AQPs decreased over time, while CSF AQPs levels increased. In turn, astrocytes AQP4 increased in SHR rats. These AQP alterations may underlie hypertensive-dependent ventriculomegaly.
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AQP4, Astrogenesis, and Hydrocephalus: A New Neurological Perspective. Int J Mol Sci 2022; 23:ijms231810438. [PMID: 36142348 PMCID: PMC9498986 DOI: 10.3390/ijms231810438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 09/03/2022] [Accepted: 09/06/2022] [Indexed: 11/16/2022] Open
Abstract
Aquaporin 4 (AQP4) is a cerebral glial marker that labels ependymal cells and astrocytes’ endfeet and is the main water channel responsible for the parenchymal fluid balance. However, in brain development, AQP4 is a marker of glial stem cells and plays a crucial role in the pathophysiology of pediatric hydrocephalus. Gliogenesis characterization has been hampered by a lack of biomarkers for precursor and intermediate stages and a deeper understanding of hydrocephalus etiology is needed. This manuscript is a focused review of the current research landscape on AQP4 as a possible biomarker for gliogenesis and its influence in pediatric hydrocephalus, emphasizing reactive astrogliosis. The goal is to understand brain development under hydrocephalic and normal physiologic conditions.
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Gonzalez-Marrero I, Hernández-Abad LG, Castañeyra-Ruiz L, Carmona-Calero EM, Castañeyra-Perdomo A. Changes in the choroid plexuses and brain barriers associated with high blood pressure and ageing. Neurologia 2022; 37:371-382. [PMID: 30060976 DOI: 10.1016/j.nrl.2018.06.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 05/29/2018] [Accepted: 06/11/2018] [Indexed: 01/12/2023] Open
Abstract
INTRODUCTION The choroid plexuses, blood vessels, and brain barriers are closely related both in terms of morphology and function. Hypertension causes changes in cerebral blood flow and in small vessels and capillaries of the brain. This review studies the effects of high blood pressure (HBP) on the choroid plexuses and brain barriers. DEVELOPMENT The choroid plexuses (ChP) are structures located in the cerebral ventricles, and are highly conserved both phylogenetically and ontogenetically. The ChPs develop during embryogenesis, forming a functional barrier during the first weeks of gestation. They are composed of highly vascularised epithelial tissue covered by microvilli, and their main function is cerebrospinal fluid (CSF) production. The central nervous system (CNS) is protected by the blood-brain barrier (BBB) and the blood-CSF barrier (BCSFB). While the BBB is formed by endothelial cells of the microvasculature of the CNS, the BCSFB is formed by epithelial cells of the choroid plexuses. Chronic hypertension induces vascular remodelling. This prevents hyperperfusion at HBPs, but increases the risk of ischaemia at low blood pressures. In normotensive individuals, in contrast, cerebral circulation is self-regulated, blood flow remains constant, and the integrity of the BBB is preserved. CONCLUSIONS HBP induces changes in the choroid plexuses that affect the stroma, blood vessels, and CSF production. HBP also exacerbates age-related ChP dysfunction and causes alterations in the brain barriers, which are more marked in the BCSFB than in the BBB. Brain barrier damage may be determined by quantifying blood S-100β and TTRm levels.
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Affiliation(s)
- I Gonzalez-Marrero
- Departamento de Anatomía, Facultad de Medicina, Universidad de La Laguna, La Laguna, Tenerife, España
| | - L G Hernández-Abad
- Instituto de Investigación y Ciencias de Puerto de Rosario, Puerto del Rosario, Fuerteventura, España
| | - L Castañeyra-Ruiz
- Departamento de Anatomía, Facultad de Medicina, Universidad de La Laguna, La Laguna, Tenerife, España; Departamento de Farmacología, Facultad de Medicina, Universidad de La Laguna, La Laguna, Tenerife, España
| | - E M Carmona-Calero
- Departamento de Anatomía, Facultad de Medicina, Universidad de La Laguna, La Laguna, Tenerife, España; Instituto de Investigación y Ciencias de Puerto de Rosario, Puerto del Rosario, Fuerteventura, España
| | - A Castañeyra-Perdomo
- Departamento de Anatomía, Facultad de Medicina, Universidad de La Laguna, La Laguna, Tenerife, España; Instituto de Investigación y Ciencias de Puerto de Rosario, Puerto del Rosario, Fuerteventura, España.
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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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Changes in the choroid plexuses and brain barriers associated with high blood pressure and ageing. NEUROLOGÍA (ENGLISH EDITION) 2020; 37:371-382. [DOI: 10.1016/j.nrleng.2020.05.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 06/11/2018] [Indexed: 01/04/2023] Open
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Johanson CE, Vío K, Guerra M, Salazar P, Jara MC, Rodríguez S, Ortega E, Castañeyra-Ruiz L, McAllister JP, Rodríguez EM. Organ Culture and Grafting of Choroid Plexus into the Ventricular CSF of Normal and Hydrocephalic HTx Rats. J Neuropathol Exp Neurol 2020; 79:626-640. [DOI: 10.1093/jnen/nlaa028] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 03/05/2020] [Indexed: 12/13/2022] Open
Abstract
AbstractChoroid plexus (CP) may aid brain development and repair by secreting growth factors and neurotrophins for CSF streaming to ventricular and subventricular zones. Disrupted ventricular/subventricular zone progenitors and stem cells lead to CNS maldevelopment. Exploring models, we organ cultured the CP and transplanted fresh CP into a lateral ventricle of postnatal hydrocephalic (hyHTx) and nonhydrocephalic (nHTx) rats. After 60 days in vitro, the cultured choroid ependyma formed spherical rings with beating cilia. Cultured CP expressed endocytotic caveolin 1 and apical aquaporin 1 and absorbed horseradish peroxidase from medium. Transthyretin secretory protein was secreted by organ-cultured CP into medium throughout 60 days in vitro. Fresh CP, surviving at 1 week after lateral ventricle implantation of nHTx or hyHTx did not block CSF flow. Avascular 1-week transplants in vivo expressed caveolin 1, aquaporin 1, and transthyretin, indicating that grafted CP may secrete trophic proteins but not CSF. Our findings encourage further exploration on CP organ culture and grafting for translational strategies. Because transplanted CP, though not producing CSF, may secrete beneficial molecules for developing brain injured by hydrocephalus, we propose that upon CP removal in hydrocephalus surgery, the fractionated tissue could be transplanted back (ventricular autograft).
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Affiliation(s)
- Conrad E Johanson
- Department of Neurosurgery, Alpert Medical School at Brown University, Providence, Rhode Island
| | - Karin Vío
- Instituto de Anatomía, Histología y Patología
| | | | | | | | | | | | - Leandro Castañeyra-Ruiz
- Facultad de Medicina, Universidad Austral de Chile, Valdivia, Chile; Departamento de Anatomía, Facultad de Medicina, Universidad de la Laguna, San Cristóbal de La Laguna, Spain
| | - J Patrick McAllister
- Department of Neurosurgery, Washington University School of Medicine, St. Louis, Missouri
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Castañeyra-Ruiz L, Castañeyra A, González-Santana A, Machado JD, Borges R. Combining the lack of chromogranins with chronic L-DOPA treatment affects motor activity in mice. Cell Tissue Res 2020; 380:59-66. [PMID: 31900665 DOI: 10.1007/s00441-019-03159-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 12/10/2019] [Indexed: 11/29/2022]
Abstract
We have tested whether the lack of chromogranins (Cgs) A and B could provoke CNS disorders when combined with an excess of dopamine. We chronically treated (over 6 months) mice lacking both chromogranins A and B (Cgs-KO) with a low oral dosage of L-DOPA/benserazide (10/2.5 mg/kg). Motor performance in the rota-rod test, open field activity, and metabolic cages indicated a progressive impairment in motor coordination in these mice, and an increase in rearing behavior, which was accompanied by an increase in DA within the substantia nigra. We conclude that mild chronic L-DOPA treatment does not produce nigro-striatal toxicity that could be associated with parkinsonism, neither in control nor Cgs-KO mice. Rather, Cgs-KO mice exhibit behaviors compatible with an amphetamine-like effect, probably caused by the excess of catecholamines in the CNS.
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Affiliation(s)
- Leandro Castañeyra-Ruiz
- Department of Neurosurgery, School of Medicine, Washington University in Saint Louis, St. Louis, MO, USA
- Unidad de Farmacología, Facultad de Medicina, Universidad de La Laguna, E-38200, La Laguna, Tenerife, Spain
| | - Agustín Castañeyra
- Dept. Ciencias Médicas Basicas, Facultad de Medicina, Universidad de La Laguna, Tenerife, Spain
| | - Ayoze González-Santana
- Department of Neurosurgery, School of Medicine, Washington University in Saint Louis, St. Louis, MO, USA
- Unidad de Farmacología, Facultad de Medicina, Universidad de La Laguna, E-38200, La Laguna, Tenerife, Spain
- Dept. Ciencias Médicas Basicas, Facultad de Medicina, Universidad de La Laguna, Tenerife, Spain
| | - José D Machado
- Unidad de Farmacología, Facultad de Medicina, Universidad de La Laguna, E-38200, La Laguna, Tenerife, Spain
| | - Ricardo Borges
- Unidad de Farmacología, Facultad de Medicina, Universidad de La Laguna, E-38200, La Laguna, Tenerife, Spain.
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Castañeyra-Ruiz L, Hernández-Abad LG, Carmona-Calero EM, Castañeyra-Perdomo A, González-Marrero I. AQP1 Overexpression in the CSF of Obstructive Hydrocephalus and Inversion of Its Polarity in the Choroid Plexus of a Chiari Malformation Type II Case. J Neuropathol Exp Neurol 2019; 78:641-647. [DOI: 10.1093/jnen/nlz033] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Affiliation(s)
- Leandro Castañeyra-Ruiz
- Department of Neurological Surgery, Washington University, School of Medicine and the St. Louis Children’s Hospital, St. Louis, Missouri
| | | | - Emilia M Carmona-Calero
- Departamento de Anatomía, Anatomía, Patológica e Histología, Facultad de Medicina, Universidad de La Laguna, La Laguna, Tenerife, Islas Canarias, Spain
| | - Agustín Castañeyra-Perdomo
- Departamento de Anatomía, Anatomía, Patológica e Histología, Facultad de Medicina, Universidad de La Laguna, La Laguna, Tenerife, Islas Canarias, Spain
| | - Ibrahim González-Marrero
- Departamento de Anatomía, Anatomía, Patológica e Histología, Facultad de Medicina, Universidad de La Laguna, La Laguna, Tenerife, Islas Canarias, Spain
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Meyer G, González-Arnay E, Moll U, Nemajerova A, Tissir F, González-Gómez M. Cajal-Retzius neurons are required for the development of the human hippocampal fissure. J Anat 2019; 235:569-589. [PMID: 30861578 DOI: 10.1111/joa.12947] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/10/2019] [Indexed: 01/14/2023] Open
Abstract
Cajal-Retzius neurons (CRN) are the main source of Reelin in the marginal zone of the developing neocortex and hippocampus (HC). They also express the transcription factor p73 and are complemented by later-appearing GABAergic Reelin+ interneurons. The human dorsal HC forms at gestational week 10 (GW10), when it develops a rudimentary Ammonic plate and incipient dentate migration, although the dorsal hippocampal fissure (HF) remains shallow and contains few CRN. The dorsal HC transforms into the indusium griseum (IG), concurrently with the rostro-caudal appearance of the corpus callosum, by GW14-17. Dorsal and ventral HC merge at the site of the former caudal hem, which is located at the level of the future atrium of the lateral ventricle and closely connected with the choroid plexus. The ventral HC forms at GW11 in the temporal lobe. The ventral HF is wide open at GW14-16 and densely populated by large numbers of CRNs. These are in intimate contact with the meninges and meningeal blood vessels, suggesting signalling through diverse pathways. At GW17, the fissure deepens and begins to fuse, although it is still marked by p73/Reelin+ CRNs. The p73KO mouse illustrates the importance of p73 in CRN for HF formation. In the mutant, Tbr1/Reelin+ CRNs are born in the hem but do not leave it and subsequently disappear, so that the mutant cortex and HC lack CRN from the onset of corticogenesis. The HF is absent, which leads to profound architectonic alterations of the HC. To determine which p73 isoform is important for HF formation, isoform-specific TAp73- and DeltaNp73-deficient embryonic and early postnatal mice were examined. In both mutants, the number of CRNs was reduced, but each of their phenotypes was much milder than in the global p73KO mutant missing both isoforms. In the TAp73KO mice, the HF of the dorsal HC failed to form, but was present in the ventral HC. In the DeltaNp73KO mice, the HC had a mild patterning defect along with a shorter HF. Complex interactions between both isoforms in CRNs may contribute to their crucial activity in the developing brain.
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Affiliation(s)
- Gundela Meyer
- Department of Basic Medical Sciences, University La Laguna, La Laguna, Spain
| | | | - Ute Moll
- Department of Pathology, Stony Brook University, Stony Brook, NY, USA
| | - Alice Nemajerova
- Department of Pathology, Stony Brook University, Stony Brook, NY, USA
| | - Fadel Tissir
- Developmental Neurobiology Group, Institute of NeuroScience, UCL Louvain, Brussels, Belgium
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