Project description:Choroid plexus secretes cerebrospinal fluid important for brain development and homeostasis. The OTX2 homeoprotein is critical for choroid plexus development and remains highly expressed in adult choroid plexus. Through RNA sequencing analyses of constitutive and conditional knockdown adult mouse models, we reveal putative roles for OTX2 in choroid plexus function, including cell signaling and adhesion, and show that it regulates the expression of factors secreted into cerebrospinal fluid, notably transthyretin. We also show that Otx2 expression impacts choroid plexus immune and stress responses, and also affects splicing which leads to changes in mRNA isoforms of proteins implicated in oxidative stress response and DNA repair. Through mass spectrometry analysis of OTX2 protein partners in the choroid plexus, and in known non-cell autonomous target regions such as visual cortex and subventricular zone, we identified putative targets involved in cell adhesion, chromatin structure and RNA processing. Thus, OTX2 retains important roles in choroid plexus function and brain homeostasis throughout life.
Project description:To analyze OTX2 function in adult choroid plexus, we performed several OTX2 co-immunoprecipitation (co-IP) experiments with mass spectrometry analysis to identify potential protein partners. We previously discovered that OTX2 protein also accumulates non-cell autonomously in subventricular zone (SVZ) and rostral migratory stream (RMS) astrocytes and in visual cortex (VCx) parvalbumin cells. The identification of alternate protein partners in cell-autonomous and non-cell-autonomous contexts would suggest OTX2 takes on specific roles after transferring between cells. In order to test this hypothesis, and to reinforce choroid plexus analysis, we also performed OTX2 co-IP on lysates from adult mouse SVZ, RMS and VCx.
Project description:The choroid plexuses (ChPs) are the main regulators of cerebrospinal fluid (CSF) composition and thereby also control the composition of a principal source of signaling molecules that is in direct contact with neural stem cells in the developing brain. The regulators of ChP development mediating the acquisition of a fate that differs from the neighboring neuroepithelial cells are poorly understood. Here, we demonstrate in mice a crucial role for the transcription factor Otx2 in the development and maintenance of ChP cells. Deletion of Otx2 by the Otx2-CreERT2 driver line at E9 resulted in a lack of all ChPs, whereas deletion by the Gdf7-Cre driver line affected predominately the hindbrain ChP, which was reduced in size, primarily owing to an increase in apoptosis upon Otx2 deletion. Strikingly, Otx2 was still required for the maintenance of hindbrain ChP cells at later stages when Otx2 deletion was induced at E15, demonstrating a central role of Otx2 in ChP development and maintenance. Moreover, the predominant defects in the hindbrain ChP mediated by Gdf7-Cre deletion of Otx2 revealed its key role in regulating early CSF composition, which was altered in protein content, including the levels of Wnt4 and the Wnt modulator Tgm2. Accordingly, proliferation and Wnt signaling levels were increased in the distant cerebral cortex, suggesting a role of the hindbrain ChP in regulating CSF composition, including key signaling molecules. Thus, Otx2 acts as a master regulator of ChP development, thereby influencing one of the principal sources of signaling in the developing brain, the CSF. We performed gene expression microarray analysis of fourth ventricular choroid plexus tissue from Otx2 k.o. mice compared to wildtype mice from the same litters.
Project description:Atoh1-Cre; Myc/Myc mice developed choroid plexus papilloma and Atoh1-Cre; Myc/Myc; p53fl/fl mice developed choroid plexus carcinoma. By studying the gene expression profiles of normal choroid plexus, choroid plexus papilloma and choroid plexus carcinoma in mice, we aim to gain a better understanding of the biology of choroid plexus tumors
Project description:The choroid plexuses (ChPs) are the main regulators of cerebrospinal fluid (CSF) composition and thereby also control the composition of a principal source of signaling molecules that is in direct contact with neural stem cells in the developing brain. The regulators of ChP development mediating the acquisition of a fate that differs from the neighboring neuroepithelial cells are poorly understood. Here, we demonstrate in mice a crucial role for the transcription factor Otx2 in the development and maintenance of ChP cells. Deletion of Otx2 by the Otx2-CreERT2 driver line at E9 resulted in a lack of all ChPs, whereas deletion by the Gdf7-Cre driver line affected predominately the hindbrain ChP, which was reduced in size, primarily owing to an increase in apoptosis upon Otx2 deletion. Strikingly, Otx2 was still required for the maintenance of hindbrain ChP cells at later stages when Otx2 deletion was induced at E15, demonstrating a central role of Otx2 in ChP development and maintenance. Moreover, the predominant defects in the hindbrain ChP mediated by Gdf7-Cre deletion of Otx2 revealed its key role in regulating early CSF composition, which was altered in protein content, including the levels of Wnt4 and the Wnt modulator Tgm2. Accordingly, proliferation and Wnt signaling levels were increased in the distant cerebral cortex, suggesting a role of the hindbrain ChP in regulating CSF composition, including key signaling molecules. Thus, Otx2 acts as a master regulator of ChP development, thereby influencing one of the principal sources of signaling in the developing brain, the CSF.
Project description:Gene expression profiles generated from human tumor cells laser-microdissected from surgical samples of seven choroid plexus papillomas (Grade I WHO) as eight samples of epithelial cells lasermicrodissected from normal choroid plexus obtained at autopsy. Choroid plexus tumors are rare pediatric brain tumors derrived from the choroid plexus epithelium. Gene expression profiles of lasermicrodissected tumor cells from 7 individual choroid plexus tumor samples obtained at surgery were compared to gene expression profiles from non-neoplastic choroid plexus epithelial cells lasermicrodissected from normal non-neoplastic choroid plexus obtained at autopsy (Am J Surg Pathol. 2006 Jan;30(1):66-74.) in order to identfy genes differentially expressed in choroid plexus tumor cells.
Project description:Aggresome is a para nuclear inclusion body that functions as a storage compartment for misfolded proteins. Our previous work revealed the presence of aggresomes in pediatric choroid plexus tumors (CPT). CPTs are rare neoplasms comprised of three pathological subgroups; choroid plexus carcinoma (CPC), a grade III tumor, atypical choroid plexus papilloma (ACPP), a grade II tumor, and choroid plexus papilloma (CPP), a grade I tumor. In the current study, we aimed to investigate the prognostic value of aggresomes-positivity and its correlation to the pathological and molecular subtypes. The proteomics profiling of 21 CPT pediatric samples was investigated using ABSciex Triple TOF 5600+ mass spectrometer.
Project description:Aggresome is a para nuclear inclusion body that functions as a storage compartment for misfolded proteins. Our previous work revealed the presence of aggresomes in pediatric choroid plexus tumors (CPT). CPTs are rare neoplasms comprised of three pathological subgroups; choroid plexus carcinoma (CPC), a grade III tumor, atypical choroid plexus papilloma (ACPP), a grade II tumor, and choroid plexus papilloma (CPP), a grade I tumor. In the current study, we aimed to investigate the prognostic value of aggresomes-positivity and its correlation to the pathological and molecular subtypes. The genome-wide methylation profile of 42 CPT pediatric samples was investigated using Illumina Infinium Methylation EPIC BeadChip array.