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González M, Maurelia F, Aguayo J, Amigo R, Arrué R, Gutiérrez JL, Torrejón M, Farkas C, Caprile T. Uncovering the role of the subcommissural organ in early brain development through transcriptomic analysis. Biol Res 2024; 57:49. [PMID: 39068496 PMCID: PMC11282827 DOI: 10.1186/s40659-024-00524-y] [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: 05/01/2024] [Accepted: 06/14/2024] [Indexed: 07/30/2024] Open
Abstract
BACKGROUND The significant role of embryonic cerebrospinal fluid (eCSF) in the initial stages of brain development has been thoroughly studied. This fluid contains crucial molecules for proper brain development such as members of the Wnt and FGF families, apolipoproteins, and retinol binding protein. Nevertheless, the source of these molecules remains uncertain since they are present before the formation of the choroid plexus, which is conventionally known as the primary producer of cerebrospinal fluid. The subcommissural organ (SCO) is a highly conserved gland located in the diencephalon and is one of the earliest differentiating brain structures. The SCO secretes molecules into the eCSF, prior to the differentiation of the choroid plexus, playing a pivotal role in the homeostasis and dynamics of this fluid. One of the key molecules secreted by the SCO is SCO-spondin, a protein involved in maintenance of the normal ventricle size, straight spinal axis, neurogenesis, and axonal guidance. Furthermore, SCO secretes transthyretin and basic fibroblast growth factor 2, while other identified molecules in the eCSF could potentially be secreted by the SCO. Additionally, various transcription factors have been identified in the SCO. However, the precise mechanisms involved in the early SCO development are not fully understood. RESULTS To uncover key molecular players and signaling pathways involved in the role of the SCO during brain development, we conducted a transcriptomic analysis comparing the embryonic chick SCO at HH23 and HH30 stages (4 and 7 days respectively). Additionally, a public transcriptomic data from HH30 entire chick brain was used to compare expression levels between SCO and whole brain transcriptome. These analyses revealed that, at both stages, the SCO differentially expresses several members of bone morphogenic proteins, Wnt and fibroblast growth factors families, diverse proteins involved in axonal guidance, neurogenic and differentiative molecules, cell receptors and transcription factors. The secretory pathway is particularly upregulated at stage HH30 while the proliferative pathway is increased at stage HH23. CONCLUSION The results suggest that the SCO has the capacity to secrete several morphogenic molecules to the eCSF prior to the development of other structures, such as the choroid plexus.
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Affiliation(s)
- Maryori González
- Departamento de Biología Celular, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Felipe Maurelia
- Departamento de Biología Celular, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Jaime Aguayo
- Departamento de Biología Celular, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Roberto Amigo
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Rodrigo Arrué
- Departamento de Biología Celular, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - José Leonardo Gutiérrez
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Marcela Torrejón
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Carlos Farkas
- Departamento de Ciencias Básicas y Morfología, Facultad de Medicina, Universidad Católica de la Santísima Concepción, Concepción, Chile.
| | - Teresa Caprile
- Departamento de Biología Celular, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile.
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Duan X, Shao Y, Che Z, Zhao X, Guo M, Li C, Liang W. Genome-wide identification m 6A modified circRNAs revealed their key roles in skin ulceration syndrome disease development in Apostichopus japonicus. FISH & SHELLFISH IMMUNOLOGY 2022; 127:748-757. [PMID: 35835384 DOI: 10.1016/j.fsi.2022.07.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 07/01/2022] [Accepted: 07/04/2022] [Indexed: 06/15/2023]
Abstract
Circular RNAs (circRNAs) are novel endogenous non-coding RNAs (ncRNAs) and can be acted as competing endogenous RNAs (ceRNAs) to regulate microRNA (miRNA) and downstream gene expression. Recently, m6A modification has been found in circRNA, and m6A circRNAs also play important roles in various biological processes and a variety of diseases. Our previous study had been demonstrated that circRNAs were differentially expressed in skin ulceration syndrome (SUS) diseased sea cucumber Apostichopus japonicus. However, whether the function of circRNAs are dependent on m6A levels are largely unknown. Here, we firstly investigated the genome-wide map of m6A circRNAs in sea cucumbers with different stages of Vibrio splendidus challenge, that's Control group, SUS-diseased group, and SUS-resistant group. MeRIP-seq revealed that m6A abundances were enriched in circRNAs in all three groups, especially for SUS-resistant group. Among them, more than 62% of modified circRNAs harbor only a single m6A peak and about 55% of m6A sites in circRNAs were derived from sense overlapping in each group. After V. splendidus infection, we found that most of m6A peaks in circRNAs were upregulated and less were downregulated in both SUS-diseased and SUS-resistant groups when compared with Control. Furthermore, GO analysis indicated that the host genes of circRNAs with dysregulated m6A peaks in SUS-diseased and SUS-resistant groups were both mainly enriched in the adhesion pathway. More importantly, we discovered that more than 50% m6A circRNAs showed a positive correlation between the circRNAs expression and m6A methylation levels both in SUS-diseased and SUS-resistant groups. Therefore, a core circRNA-miRNA-mRNA (ceRNA) network whether influenced by m6A modification was constructed based on conjoint analysis. Our results indicated that several selected m6A circRNAs bind with miRNAs were mainly targeting to ubiquitylation system and adhesion pathway. What's more, three candidate m6A circRNAs and three target genes were validated by MeRIP-qPCR and qPCR, whose m6A levels in circRNA and mRNA expressions were consistent with disease occurrence or disease resistance. All of our current findings suggested that m6A circRNAs could play important roles during pathogen infection and might be served as a new molecular biomarker in SUS disease diagnose of A. japonicus.
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Affiliation(s)
- Xuemei Duan
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, Ningbo, 315211, PR China
| | - Yina Shao
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, Ningbo, 315211, PR China.
| | - Zhongjie Che
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, Ningbo, 315211, PR China
| | - Xuelin Zhao
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, Ningbo, 315211, PR China
| | - Ming Guo
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, Ningbo, 315211, PR China
| | - Chenghua Li
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, Ningbo, 315211, PR China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, PR China.
| | - Weikang Liang
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, Ningbo, 315211, PR China.
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Rapid screening for Mycobacterium tuberculosis complex in clinical elephant trunk wash samples. Res Vet Sci 2017; 112:52-58. [PMID: 28126601 DOI: 10.1016/j.rvsc.2016.12.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Revised: 12/06/2016] [Accepted: 12/30/2016] [Indexed: 11/23/2022]
Abstract
Mycobacterium tuberculosis can infect and be transmitted between elephants and humans. In elephants, the 'gold standard' reference test for detection of tuberculosis is culture, which takes a minimum of eight weeks for results and has limited sensitivity. A screening test that is rapid, easily implemented, and accurate is needed to aid in diagnosis of tuberculosis in elephants. Ninety-nine clinical trunk wash samples obtained from 33 elephants were utilized to validate three molecular extraction techniques followed by a polymerase chain reaction for detection of M. tuberculosis. Diagnostic sensitivity and specificity were estimated compared to culture. Kappa coefficients were determined between molecular results and various culture categories and serological test results. An internal amplification control was developed and assessed to monitor for PCR inhibition. One molecular test (the Column method) outperformed the other two, with diagnostic sensitivity and kappa agreement estimates of 100% (CI 57-100) and 0.46 (CI 0.2-0.74), respectively, compared to culture alone. The percentage of molecular-positive/culture-negative samples was 8.4% overall. The molecular extraction technique followed by PCR provides a much-needed rapid screening tool for detection of tuberculosis in elephants. Immediate procedures can be implemented to further assess PCR-positive animals and provide personnel biosecurity. While a positive result is not a definitive test for elephant tuberculosis, the molecular test results can be used to support current diagnostic procedures applied by veterinarians for treatment decisions to prevent the spread of tuberculosis in elephants.
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Stanic K, Saldivia N, Förstera B, Torrejón M, Montecinos H, Caprile T. Expression Patterns of Extracellular Matrix Proteins during Posterior Commissure Development. Front Neuroanat 2016; 10:89. [PMID: 27733818 PMCID: PMC5039192 DOI: 10.3389/fnana.2016.00089] [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: 07/05/2016] [Accepted: 09/12/2016] [Indexed: 11/13/2022] Open
Abstract
Extracellular matrix (ECM) molecules are pivotal for central nervous system (CNS) development, facilitating cell migration, axonal growth, myelination, dendritic spine formation, and synaptic plasticity, among other processes. During axon guidance, the ECM not only acts as a permissive or non-permissive substrate for navigating axons, but also modulates the effects of classical guidance cues, such as netrin or Eph/ephrin family members. Despite being highly important, little is known about the expression of ECM molecules during CNS development. Therefore, this study assessed the molecular expression patterns of tenascin, HNK-1, laminin, fibronectin, perlecan, decorin, and osteopontin along chick embryo prosomere 1 during posterior commissure development. The posterior commissure is the first transversal axonal tract of the embryonic vertebrate brain. Located in the dorso-caudal portion of prosomere 1, posterior commissure axons primarily arise from the neurons of basal pretectal nuclei that run dorsally to the roof plate midline, where some turn toward the ipsilateral side. Expressional analysis of ECM molecules in this area these revealed to be highly arranged, and molecule interactions with axon fascicles suggested involvement in processes other than structural support. In particular, tenascin and the HNK-1 epitope extended in ventro-dorsal columns and enclosed axons during navigation to the roof plate. Laminin and osteopontin were expressed in the midline, very close to axons that at this point must decide between extending to the contralateral side or turning to the ipsilateral side. Finally, fibronectin, decorin, and perlecan appeared unrelated to axonal pathfinding in this region and were instead restricted to the external limiting membrane. In summary, the present report provides evidence for an intricate expression of different extracellular molecules that may cooperate in guiding posterior commissure axons.
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Affiliation(s)
- Karen Stanic
- Axon Guidance Laboratory, Department of Cell Biology, Faculty of Biological Sciences, University of Concepción Concepción, Chile
| | - Natalia Saldivia
- Axon Guidance Laboratory, Department of Cell Biology, Faculty of Biological Sciences, University of Concepción Concepción, Chile
| | - Benjamín Förstera
- Department of Physiology, Faculty of Biological Sciences, University of Concepción Concepción, Chile
| | - Marcela Torrejón
- Department of Biochemistry and Molecular Biology, Faculty of Biological Sciences, University of Concepción Concepción, Chile
| | - Hernán Montecinos
- Axon Guidance Laboratory, Department of Cell Biology, Faculty of Biological Sciences, University of Concepción Concepción, Chile
| | - Teresa Caprile
- Axon Guidance Laboratory, Department of Cell Biology, Faculty of Biological Sciences, University of Concepción Concepción, Chile
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Linke LM, Wilusz J, Pabilonia KL, Fruehauf J, Magnuson R, Olea-Popelka F, Triantis J, Landolt G, Salman M. Inhibiting avian influenza virus shedding using a novel RNAi antiviral vector technology: proof of concept in an avian cell model. AMB Express 2016; 6:16. [PMID: 26910902 PMCID: PMC4766140 DOI: 10.1186/s13568-016-0187-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2015] [Accepted: 02/18/2016] [Indexed: 01/24/2023] Open
Abstract
Influenza A viruses pose significant health and economic threats to humans and animals. Outbreaks of avian influenza virus (AIV) are a liability to the poultry industry and increase the risk for transmission to humans. There are limitations to using the AIV vaccine in poultry, creating barriers to controlling outbreaks and a need for alternative effective control measures. Application of RNA interference (RNAi) techniques hold potential; however, the delivery of RNAi-mediating agents is a well-known obstacle to harnessing its clinical application. We introduce a novel antiviral approach using bacterial vectors that target avian mucosal epithelial cells and deliver (small interfering RNA) siRNAs against two AIV genes, nucleoprotein (NP) and polymerase acidic protein (PA). Using a red fluorescent reporter, we first demonstrated vector delivery and intracellular expression in avian epithelial cells. Subsequently, we demonstrated significant reductions in AIV shedding when applying these anti-AIV vectors prophylactically. These antiviral vectors provided up to a 10,000-fold reduction in viral titers shed, demonstrating in vitro proof-of-concept for using these novel anti-AIV vectors to inhibit AIV shedding. Our results indicate this siRNA vector technology could represent a scalable and clinically applicable antiviral technology for avian and human influenza and a prototype for RNAi-based vectors against other viruses.
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Guerra MM, González C, Caprile T, Jara M, Vío K, Muñoz RI, Rodríguez S, Rodríguez EM. Understanding How the Subcommissural Organ and Other Periventricular Secretory Structures Contribute via the Cerebrospinal Fluid to Neurogenesis. Front Cell Neurosci 2015; 9:480. [PMID: 26778959 PMCID: PMC4689152 DOI: 10.3389/fncel.2015.00480] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 11/26/2015] [Indexed: 12/13/2022] Open
Abstract
The dynamic and molecular composition of the cerebrospinal fluid (CSF) and, consequently, the CSF physiology is much more complex and fascinating than the simplistic view held for decades. Signal molecules either transported from blood to CSF or secreted into the CSF by circumventricular organs and CSF-contacting neurons, use the CSF to reach their targets in the brain, including the pre- and postnatal neurogenic niche. The subcommissural organ (SCO), a highly conserved brain gland present throughout the vertebrate phylum, is one of the sources for signals, as well as the choroid plexus, tanycytes and CSF-contacting neurons. The SCO secretes into the fetal and adult CSF SCO-spondin, transthyretin, and basic fibroblast growth factor. These proteins participate in certain aspects of neurogenesis, such as cell cycle of neural stem cells, neuronal differentiation, and axon pathfinding. Through the CSF, the SCO-secretory proteins may reach virtually any target in the embryonic and adult central nervous system. Since the SCO continues to secrete throughout life span, it seems likely that the neurogenetic property of the SCO compounds would be targeted to the niches where neurogenesis continues in adulthood. This review is aimed to bring into discussion early and new evidence concerning the role(s) of the SCO, and the probable mechanisms by which SCO compounds can readily reach the neurogenic niche of the subventricular zone flowing with the CSF to participate in the regulation of the neurogenic niche. As we unfold the multiples trans-fluid talks between discrete brain domains we will have more tools to influence such talks.
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Affiliation(s)
- Maria M Guerra
- Instituto de Anatomía, Histología y Patología, Facultad de Medicina, Universidad Austral de Chile Valdivia, Chile
| | - César González
- Instituto de Anatomía, Histología y Patología, Facultad de Medicina, Universidad Austral de Chile Valdivia, Chile
| | - Teresa Caprile
- Departamento de Biología Celular, Facultad de Ciencias Biológicas, Universidad de Concepción Concepción, Chile
| | - Maryoris Jara
- 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
| | - Rosa I Muñoz
- 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
| | - Esteban M Rodríguez
- Instituto de Anatomía, Histología y Patología, Facultad de Medicina, Universidad Austral de Chile Valdivia, Chile
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Vera A, Recabal A, Saldivia N, Stanic K, Torrejón M, Montecinos H, Caprile T. Interaction between SCO-spondin and low density lipoproteins from embryonic cerebrospinal fluid modulates their roles in early neurogenesis. Front Neuroanat 2015; 9:72. [PMID: 26074785 PMCID: PMC4446542 DOI: 10.3389/fnana.2015.00072] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 05/14/2015] [Indexed: 01/20/2023] Open
Abstract
During early stages of development, encephalic vesicles are composed by a layer of neuroepithelial cells surrounding a central cavity filled with embryonic cerebrospinal fluid (eCSF). This fluid contains several morphogens that regulate proliferation and differentiation of neuroepithelial cells. One of these neurogenic factors is SCO-spondin, a giant protein secreted to the eCSF from early stages of development. Inhibition of this protein in vivo or in vitro drastically decreases the neurodifferentiation process. Other important neurogenic factors of the eCSF are low density lipoproteins (LDL), the depletion of which generates a 60% decrease in mesencephalic explant neurodifferentiation. The presence of several LDL receptor class A (LDLrA) domains (responsible for LDL binding in other proteins) in the SCO-spondin sequence suggests a possible interaction between both molecules. This possibility was analyzed using three different experimental approaches: (1) Bioinformatics analyses of the SCO-spondin region, that contains eight LDLrA domains in tandem, and of comparisons with the LDL receptor consensus sequence; (2) Analysis of the physical interactions of both molecules through immunohistochemical colocalization in embryonic chick brains and through the immunoprecipitation of LDL with anti-SCO-spondin antibodies; and (3) Analysis of functional interactions during the neurodifferentiation process when these molecules were added to a culture medium of mesencephalic explants. The results revealed that LDL and SCO-spondin interact to form a complex that diminishes the neurogenic capacities that both molecules have separately. Our work suggests that the eCSF is an active signaling center with a complex regulation system that allows for correct brain development.
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Affiliation(s)
- América Vera
- Department of Cell Biology, Faculty of Biological Sciences, University of Concepción Concepción, Chile
| | - Antonia Recabal
- Department of Cell Biology, Faculty of Biological Sciences, University of Concepción Concepción, Chile
| | - Natalia Saldivia
- Department of Cell Biology, Faculty of Biological Sciences, University of Concepción Concepción, Chile
| | - Karen Stanic
- Department of Cell Biology, Faculty of Biological Sciences, University of Concepción Concepción, Chile
| | - Marcela Torrejón
- Faculty of Biological Sciences, Department of Biochemistry and Molecular Biology, University of Concepción Concepción, Chile
| | - Hernán Montecinos
- Department of Cell Biology, Faculty of Biological Sciences, University of Concepción Concepción, Chile
| | - Teresa Caprile
- Department of Cell Biology, Faculty of Biological Sciences, University of Concepción Concepción, Chile
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Stanic K, Vera A, González M, Recabal A, Astuya A, Torrejón M, Montecinos H, Caprile T. Complementary expression of EphA7 and SCO-spondin during posterior commissure development. Front Neuroanat 2014; 8:49. [PMID: 25009468 PMCID: PMC4068196 DOI: 10.3389/fnana.2014.00049] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Accepted: 06/02/2014] [Indexed: 12/05/2022] Open
Abstract
Bilaterally symmetric organisms need to exchange information between the two sides of their bodies in order to integrate sensory inputs and coordinate motor control. This exchange occurs through commissures formed by neurons that project axons across the midline to the contralateral side of the central nervous system. The posterior commissure is the first transversal axonal tract of the embryonic vertebrate brain. It is located in the dorsal portion of the prosomere 1, at the caudal diencephalon. The axons of the posterior commissure principally come from neurons of ventrolateral and dorsolateral pretectal nuclei (parvocellular and magnocellular nucleus of the posterior commissure, respectively) that extend their axons toward the dorsal region. The trajectory of these axons can be divided into the following three stages: (1) dorsal axon extension towards the lateral roof plate; (2) fasciculation in the lateral roof plate; and (3) midline decision of turning to the ipsilateral side or continuing to the opposite side. The mechanisms and molecules that guide the axons during these steps are unknown. In the present work, immunohistochemical and in situ hybridization analyses were performed, with results suggesting the participation of EphA7 in guiding axons from the ventral to the dorsal region of the prosomere 1 through the generation of an axonal corridor limited by repulsive EphA7 walls. At the lateral roof plate, the axons became fasciculated in presence of SCO-spondin until reaching the midline. Finally, EphA7 expression was observed in the diencephalic midline roof plate, specifically in the region where some axons turn to the ipsilateral side, suggesting its participation in this decision. In summary, the present work proposes a mechanism of posterior commissure formation orchestrated by the complementary expression of the axon guidance cues SCO-spondin and EphA7.
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Affiliation(s)
- Karen Stanic
- Axon Guidance Laboratory, Department of Cell Biology, Faculty of Biological Sciences, University of Concepción, Concepción , Chile
| | - América Vera
- Axon Guidance Laboratory, Department of Cell Biology, Faculty of Biological Sciences, University of Concepción, Concepción , Chile
| | - Melissa González
- Axon Guidance Laboratory, Department of Cell Biology, Faculty of Biological Sciences, University of Concepción, Concepción , Chile
| | - Antonia Recabal
- Axon Guidance Laboratory, Department of Cell Biology, Faculty of Biological Sciences, University of Concepción, Concepción , Chile
| | - Allison Astuya
- Laboratory of Cell Culture and Marine Genomics, Marine Biotechnology Unit, Faculty of Natural and Oceanographic Sciences and Program COPAS Sur-Austral, University of Concepción, Concepción , Chile
| | - Marcela Torrejón
- Department of Biochemistry and Molecular Biology, Faculty of Biological Sciences, University of Concepción, Concepción , Chile
| | - Hernán Montecinos
- Axon Guidance Laboratory, Department of Cell Biology, Faculty of Biological Sciences, University of Concepción, Concepción , Chile
| | - Teresa Caprile
- Axon Guidance Laboratory, Department of Cell Biology, Faculty of Biological Sciences, University of Concepción, Concepción , Chile
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Vera A, Stanic K, Montecinos H, Torrejón M, Marcellini S, Caprile T. SCO-spondin from embryonic cerebrospinal fluid is required for neurogenesis during early brain development. Front Cell Neurosci 2013; 7:80. [PMID: 23761733 PMCID: PMC3669746 DOI: 10.3389/fncel.2013.00080] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2013] [Accepted: 05/09/2013] [Indexed: 02/04/2023] Open
Abstract
The central nervous system (CNS) develops from the neural tube, a hollow structure filled with embryonic cerebrospinal fluid (eCSF) and surrounded by neuroepithelial cells. Several lines of evidence suggest that the eCSF contains diffusible factors regulating the survival, proliferation, and differentiation of the neuroepithelium, although these factors are only beginning to be uncovered. One possible candidate as eCSF morphogenetic molecule is SCO-spondin, a large glycoprotein whose secretion by the diencephalic roof plate starts at early developmental stages. In vitro, SCO-spondin promotes neuronal survival and differentiation, but its in vivo function still remains to be elucidated. Here we performed in vivo loss of function experiments for SCO-spondin during early brain development by injecting and electroporating a specific shRNA expression vector into the neural tube of chick embryos. We show that SCO-spondin knock down induces an increase in neuroepithelial cells proliferation concomitantly with a decrease in cellular differentiation toward neuronal lineages, leading to hyperplasia in both the diencephalon and the mesencephalon. In addition, SCO-spondin is required for the correct morphogenesis of the posterior commissure and pineal gland. Because SCO-spondin is secreted by the diencephalon, we sought to corroborate the long-range function of this protein in vitro by performing gain and loss of function experiments on mesencephalic explants. We find that culture medium enriched in SCO-spondin causes an increased neurodifferentiation of explanted mesencephalic region. Conversely, inhibitory antibodies against SCO-spondin cause a reduction in neurodifferentiation and an increase of mitosis when such explants are cultured in eCSF. Our results suggest that SCO-spondin is a crucial eCSF diffusible factor regulating the balance between proliferation and differentiation of the brain neuroepithelial cells.
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Affiliation(s)
- A Vera
- Department of Cell Biology, Faculty of Biological Sciences, University of Concepción Biobío Region, Chile
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Grondona JM, Hoyo-Becerra C, Visser R, Fernández-Llebrez P, López-Ávalos MD. The subcommissural organ and the development of the posterior commissure. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2012; 296:63-137. [PMID: 22559938 DOI: 10.1016/b978-0-12-394307-1.00002-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Growing axons navigate through the developing brain by means of axon guidance molecules. Intermediate targets producing such signal molecules are used as guideposts to find distal targets. Glial, and sometimes neuronal, midline structures represent intermediate targets when axons cross the midline to reach the contralateral hemisphere. The subcommissural organ (SCO), a specialized neuroepithelium located at the dorsal midline underneath the posterior commissure, releases SCO-spondin, a large glycoprotein belonging to the thrombospondin superfamily that shares molecular domains with axonal pathfinding molecules. Several evidences suggest that the SCO could be involved in the development of the PC. First, both structures display a close spatiotemporal relationship. Second, certain mutants lacking an SCO present an abnormal PC. Third, some axonal guidance molecules are expressed by SCO cells. Finally, SCO cells, the Reissner's fiber (the aggregated form of SCO-spondin), or synthetic peptides from SCO-spondin affect the neurite outgrowth or neuronal aggregation in vitro.
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Affiliation(s)
- Jesús M Grondona
- Departamento de Biología Celular, Genética y Fisiología, Facultad de Ciencias, Universidad de Málaga, Spain.
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Stanic K, Montecinos H, Caprile T. Subdivisions of chick diencephalic roof plate: implication in the formation of the posterior commissure. Dev Dyn 2011; 239:2584-93. [PMID: 20730872 DOI: 10.1002/dvdy.22387] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The subcommissural organ (SCO) is a roof plate differentiation located in the caudal diencephalon under the posterior commissure (PC). A role for SCO and its secretory product, SCO-spondin, in the formation of the PC has been proposed. Here, we provide immunohistochemical evidence to suggest that SCO is anatomically divided in a bilateral region positive for SCO-spondin that surrounds a negative medial region. Remarkably, axons contacting the lateral region are highly fasciculated, in sharp contrast with the defasciculated axons of the medial region. In addition, lateral axon fascicles run toward the midline inside of tunnels limited by the basal prolongations of SCO cells and extracellular SCO-spondin. Our in vitro data in collagen gel matrices show that SCO-spondin induces axonal growth and fasciculation of pretectal explants. Together, our findings support the idea that SCO-spondin participates in the guidance and fasciculation of axons of the PC.
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Affiliation(s)
- Karen Stanic
- Department of Cell Biology, University of Concepción, Chile
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Barros CS, Franco SJ, Müller U. Extracellular matrix: functions in the nervous system. Cold Spring Harb Perspect Biol 2011; 3:a005108. [PMID: 21123393 DOI: 10.1101/cshperspect.a005108] [Citation(s) in RCA: 260] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
An astonishing number of extracellular matrix glycoproteins are expressed in dynamic patterns in the developing and adult nervous system. Neural stem cells, neurons, and glia express receptors that mediate interactions with specific extracellular matrix molecules. Functional studies in vitro and genetic studies in mice have provided evidence that the extracellular matrix affects virtually all aspects of nervous system development and function. Here we will summarize recent findings that have shed light on the specific functions of defined extracellular matrix molecules on such diverse processes as neural stem cell differentiation, neuronal migration, the formation of axonal tracts, and the maturation and function of synapses in the peripheral and central nervous system.
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Affiliation(s)
- Claudia S Barros
- The Scripps Research Institute, Department of Cell Biology, Dorris Neuroscience Center, La Jolla, California 92037, USA
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