Diffuse intrinsic pontine glioma (DIPG) is the main cause of brain tumor-related death among children. Until now, there is still a lack of effective therapy with prolonged overall survival for this disease. A typical strategy for preclinical cancer research is to find out the molecular differences between tumor tissue and para-tumor normal tissue, in order to identify potential therapeutic targets. Unfortunately, it is impossible to obtain normal tissue for DIPG because of the vital functions of the pons. Here we report the human fetal hindbrain-derived neural progenitor cells (pontine progenitor cells, PPCs) as normal control cells for DIPG. The PPCs not only harbored similar cell biological and molecular signatures as DIPG glioma stem cells, but also had the potential to be immortalized by the DIPG-specific mutation H3K27M in vitro. These findings provide researchers with a candidate normal control and a potential medicine carrier for preclinical research on DIPG.
Animals ; Brain Stem Neoplasms ; genetics ; metabolism ; pathology ; Cell Line, Tumor ; Cellular Senescence ; Female ; Glioma ; genetics ; metabolism ; pathology ; Histones ; genetics ; Humans ; Mice, Inbred NOD ; Mice, SCID ; Neoplasm Transplantation ; Neoplastic Stem Cells ; drug effects ; metabolism ; pathology ; Neural Stem Cells ; drug effects ; metabolism ; pathology ; Pons ; embryology ; metabolism ; pathology ; Primary Cell Culture

OBJECTIVEThis study aimed to investigate the expression pattern and function of Nuclear receptor subfamily 2 group E member 1 (Nr2e1) in retinoic acid (RA)-induced brain abnormality.

METHODSThe mouse model of brain abnormality was established by administering 28 mg/kg RA, and neural stem cells (NSCs) were isolated from the mouse embryo and cultured in vitro. Nr2e1 expression was detected by whole mount in situ hybridization, RT-PCR, and Western blotting. Nr2e1 function was determined by transducing Nr2e1 shRNA into NSCs, and the effect on the sonic hedgehog (Shh) signaling pathway was assessed in the cells. In addition, the regulation of Nr2e1 expression by RA was also determined in vitro.

RESULTSNr2e1 expression was significantly downregulated in the brain and NSCs of RA-treated mouse embryos, and knockdown of Nr2e1 affected the proliferation of NSCs in vitro. In addition, a similar expression pattern of Nr2e1 and RA receptor (RAR) α was observed after treatment of NSCs with different concentrations of RA.

CONCLUSIONOur study demonstrated that Nr2e1 could be regulated by RA, which would aid a better understanding of the mechanism underlying RA-induced brain abnormality.

Animals ; Brain ; cytology ; embryology ; Cell Proliferation ; Down-Regulation ; Gene Expression Regulation ; Gene Expression Regulation, Developmental ; drug effects ; Mice ; Mice, Inbred C57BL ; Neural Stem Cells ; drug effects ; physiology ; Receptors, Cytoplasmic and Nuclear ; genetics ; metabolism ; Tretinoin ; pharmacology

OBJECTIVETo study the pattern of CGG repeat instability within germline cells derived from two male fetuses affected with Fragile X syndrome (FXS).

METHODSThe length and methylation status of CGG repeats within the testes of a fetus carrying a full FXS mutation and another fetus carrying mosaicism FXS mutation were analyzed with Southern blotting and AmplideX FMR1 PCR. Immunohistochemistry was also applied for the measurement of FMR1 protein (FMRP) expression within the testes.

RESULTSFor the fetus carrying the full mutation, Southern blotting analysis of the PCR product has detected an expected band representing the full mutation in its brain and a premutation band of > 160 CGG repeats in its testis. Whereas the pattern of premutation/full mutation in mosaic testis was similar to that in peripheral blood and no sign of contracted fragment was found other than a band of about 160 CGG repeats. Immunohistochemistry assay with a FMRP-specific antibody demonstrated a number of FMRP-positive germ cells, which suggested a contraction from full mutation to premutation alleles.

CONCLUSIONThis study has clarified the instability pattern of CGG repeat and expression of FMRP protein within the testes of fetuses affected with FXS, confirming that the CGG repeat can contract progressively within the germline. The FMRP expression in the testis is consistent with spermatogonium proliferation, and thus the contraction from full mutation to unmethylated premutations may occur for the requirement of FMRP expression during spermatogenesis. The better understanding of FMRP function during germ cell proliferation may elucidate the mechanism underlying the contraction of full FXS mutation in male germline.

Abortion, Eugenic ; Blotting, Southern ; Brain ; embryology ; metabolism ; DNA Methylation ; Fatal Outcome ; Fetus ; cytology ; metabolism ; Fragile X Mental Retardation Protein ; genetics ; metabolism ; Fragile X Syndrome ; diagnosis ; genetics ; Humans ; Immunohistochemistry ; Male ; Mosaicism ; Mutation ; Polymerase Chain Reaction ; Spermatozoa ; metabolism ; Testis ; cytology ; embryology ; metabolism ; Trinucleotide Repeat Expansion ; genetics

OBJECTIVETo investigate the expression of neural salient serine/arginine-rich protein 1 (NSSR1) in the development of mouse brain.

METHODSBrain samples were collected from mice with different developmental stages: 9, 12, 14 d before birth (E9, E12, E14) and 1 d, 3 weeks and 3 months after birth. The expression of NSSR1 in mouse brain at different developmental stages was detected by Western blot and the distribution of NSSR1 was analyzed by immunohistochemical staining. The expression and distribution of NSSR1 in mouse brain were compared among embryos, neonatal and adult animals.

RESULTSDuring embryogenesis, the expression of NSSR1 proteins increases significantly from 0.186(E9) to 0.445(E14) and reached a high level after birth. Immunohistochemical analysis showed that in E12 embryos, NSSR1 was specifically distributed in the marginal and mantle layers. The expression of NSSR1 in hippocampus was very low in neonatal animals but stronger in adults. In cerebellar cortex, NSSR1 was widely expressed in purkinje and granule cells of adult animals, but mainly expressed in Purkinje cells in neonates.

CONCLUSIONThe expression of NSSR1 is regulated by the development of mouse brain and presents dynamic changes.

Animals ; Brain ; embryology ; growth & development ; metabolism ; Cell Cycle Proteins ; metabolism ; Mice ; Neoplasm Proteins ; metabolism ; RNA-Binding Proteins ; metabolism ; Repressor Proteins ; metabolism

OBJECTIVETo investigate the growth and development of brain derived neurophic factor(BDNF)-positive neurons in the frontal lobe of human fetus.

METHODSThe expression of the BDNF-positive neurons in the frontal lobe of human fetus in the 2(nd),3(rd),and 4(th) month of gestation were observed with the streptavidin-biotin-complex/immunoperoxidase(SABC)method.

RESULTSBy the second month of gestation,BDNF-positive neurons were seen in the subventricular layer of the frontal lobe of cerebellum.By the third month of gestation,BDNF-positive neurons in the central layer were in various shapes,with big nucleus,less cytoplasm,and small processes.By the fourth month of gestation,BDNF-positive neurons in the central layer grew larger in size,cytoplasm increased,the BDNF-positive expression was enhanced with deeper dyeing,and the nerve fibers and particles were distributed between neurons;also,the BDNF-positive neurons were seen in the marginal layer of the frontal lobe of cerebrum.

CONCLUSIONBDNF-positive neurons may participate in the early development of the frontal lobe of cerebrum of human fetus.

Brain-Derived Neurotrophic Factor ; metabolism ; Fetus ; metabolism ; Frontal Lobe ; embryology ; Humans ; Neurons ; cytology ; metabolism

We previously reported that mice lacking JSAP1 (jsap1-/-) were lethal and the brain of jsap1-/- at E18.5 exhibited multiple types of developmental defects, which included impaired axon projection of the corpus callosum and anterior commissures. In the current study, we examined whether the early telencephalic commissures were formed abnormally from the beginning of initial development or whether they arose normally, but have been progressively lost their maintenance in the absence of JSAP1. The early corpus callosum in the brain of jsap1+/+ at E15.5-E16.5 was found to cross the midline with forming a distinct U-shaped tract, whereas the early axonal tract in jsap1-/- appeared to cross the midline in a diffuse manner, but the lately arriving axons did not cross the midline. In the brain of jsap1-/- at E17.5, the axon terminals of lately arriving collaterals remained within each hemisphere, forming an early Probst's bundle-like shape. The early anterior commissure in the brain of jsap1+/+ at E14.5-E15.5 crossed the midline, whereas the anterior commissure in jsap1-/- developed, but was deviated from their normal path before approaching the midline. The axon tracts of the corpus callosum and anterior commissure in the brain of jsap1-/- at E16.5-E17.5 expressed phosphorylated forms of FAK and JNK, however, their expression levels in the axonal tracts were reduced compared to the respective controls in jsap1+/+. Considering the known scaffolding function of JSAP1 for the FAK and JNK pathways, these results suggest that JSAP1 is required for the pathfinding of the developing telencephalic commissures in the early brains.
Adaptor Proteins, Signal Transducing/genetics/*metabolism ; Animals ; Brain/*embryology/*metabolism ; Female ; Focal Adhesion Kinase 1/genetics/metabolism ; Immunohistochemistry ; In Situ Nick-End Labeling ; JNK Mitogen-Activated Protein Kinases/genetics/metabolism ; Mice ; Mice, Knockout ; Nerve Tissue Proteins/genetics/*metabolism ; Pregnancy ; Telencephalon/*embryology/*metabolism

Recent collaborative, large-scale genomic profiling of the most common and aggressive brain tumor glioblastoma multiforme(GBM) has significantly advanced our understanding of this disease. The gene encoding platelet-derived growth factor receptor alpha(PDGFRα) was identified as the third of the top 11 amplified genes in clinical GBM specimens. The important roles of PDGFRα signaling during normal brain development also implicate the possible pathologic consequences of PDGFRα over-activation in glioma. Although the initial clinical trials using PDGFR kinase inhibitors have been predominantly disappointing, diagnostic and treatment modalities involving genomic profiling and personalized medicine are expected to improve the therapy targeting PDGFRα signaling. In this review, we discuss the roles of PDGFRαsignaling during development of the normal central nervous system(CNS) and in pathologic conditions such as malignant glioma. We further compare various animal models of PDGF-induced gliomagenesis and their potential as a novel platform of pre-clinical drug testing. We then summarize our recent publication and how these findings will likely impact treatments for gliomas driven by PDGFRα overexpression. A better understanding of PDGFRα signaling in glioma and their microenvironment, through the use of human or mouse models, is necessary to design a more effective therapeutic strategy against gliomas harboring the aberrant PDGFRα signaling.
Animals ; Antineoplastic Agents ; therapeutic use ; Autocrine Communication ; Brain Neoplasms ; drug therapy ; genetics ; metabolism ; Central Nervous System ; cytology ; embryology ; metabolism ; Disease Models, Animal ; Glioblastoma ; drug therapy ; genetics ; metabolism ; Glioma ; drug therapy ; genetics ; metabolism ; Humans ; Neurons ; cytology ; metabolism ; Protein Kinase Inhibitors ; therapeutic use ; Receptor, Platelet-Derived Growth Factor alpha ; genetics ; metabolism

Wnt inhibitor factor-1 (WIF-1) is an extracellular antagonist of Wnts secreted proteins, first characterized as an expressed sequence tag in the human retina. WIF-1 belongs to the secreted Frizzled-related protein (sFRP) class, which can directly bind to Wnt proteins, prevent Wnts from binding to their receptors in vertebrates. Wif1 is expressed in the nervous system of mouse, Xenopus, zebrafish and human. It has been shown that WIF-1 affects the formation of somites in Xenopus embryos and inhibits rod production in retinal histogenesis by binding to Wnt4 in mice. Histological information of Wif1 expression during the development of the central nervous system has been reported in mouse, Xenopus and zebrafish and the strong embryonic expression suggests Wif1 may play an essential role in the spatial and temporal regulation of Wnt signals in development of central nervous system. The Wnt pathway plays a key role in the patterning of the nervous system. However, insights into the function of Wif1 in the development of the central nervous system are rather limited. Selecting suitable stage and target according to the expression pattern may contribute to understanding the function of Wif1.
Adaptor Proteins, Signal Transducing ; biosynthesis ; physiology ; Animals ; Brain ; embryology ; metabolism ; Central Nervous System ; embryology ; metabolism ; Extracellular Matrix Proteins ; biosynthesis ; physiology ; Gene Expression ; Humans ; Intercellular Signaling Peptides and Proteins ; biosynthesis ; physiology ; Mice ; Repressor Proteins ; biosynthesis ; physiology ; Signal Transduction ; physiology ; Spinal Cord ; embryology ; metabolism ; Xenopus

Neural progenitor cells (NPs) have shown several promising benefits for the treatment of neurological disorders. To evaluate the therapeutic potential of human neural progenitor cells (hNPs) in amyotrophic lateral sclerosis (ALS), we transplanted hNPs or growth factor (GF)-expressing hNPs into the central nervous system (CNS) of mutant Cu/Zn superoxide dismutase (SOD(1G93A)) transgenic mice. The hNPs were engineered to express brain-derived neurotrophic factor (BDNF), insulin-like growth factor-1 (IGF-1), VEGF, neurotrophin-3 (NT-3), or glial cell-derived neurotrophic factor (GDNF), respectively, by adenoviral vector and GDNF by lentiviral vector before transplantation. Donor-derived cells engrafted and migrated into the spinal cord or brain of ALS mice and differentiated into neurons, oligodendrocytes, or glutamate transporter-1 (GLT1)-expressing astrocytes while some cells retained immature markers. Transplantation of GDNF- or IGF-1-expressing hNPs attenuated the loss of motor neurons and induced trophic changes in motor neurons of the spinal cord. However, improvement in motor performance and extension of lifespan were not observed in all hNP transplantation groups compared to vehicle-injected controls. Moreover, the lifespan of GDNF-expressing hNP recipient mice by lentiviral vector was shortened compared to controls, which was largely due to the decreased survival times of female animals. These results imply that although implanted hNPs differentiate into GLT1-expressing astrocytes and secrete GFs, which maintain dying motor neurons, inadequate trophic support could be harmful and there is sexual dimorphism in response to GDNF delivery in ALS mice. Therefore, additional therapeutic approaches may be required for full functional recovery.
Adenoviridae/genetics ; Amyotrophic Lateral Sclerosis/metabolism/mortality/*therapy ; Animals ; Astrocytes/metabolism ; Brain/*embryology ; Cell Differentiation ; Disease Models, Animal ; Excitatory Amino Acid Transporter 2/metabolism ; Female ; Fetal Stem Cells/*metabolism ; Genetic Vectors ; Humans ; Immunoenzyme Techniques ; Male ; Mice ; Mice, Transgenic ; Motor Neurons/*physiology ; Nerve Growth Factors/*metabolism ; *Stem Cell Transplantation ; Superoxide Dismutase/genetics ; Transfection ; Vascular Endothelial Growth Factor A/genetics/metabolism

OBJECTIVETo investigate the expression of recombination activating gene-1 (RAG-1) and its localization in the mouse brain during the embryonic development.

METHODSThe brain tissues of E (embryonic day) 11, E13, E15, E17, E19, P0 (the birth day) and adult mice were taken, the total RNA of brains were extracted and the changes of RAG-1 expression were detected with the method of RT-PCR. The freeze sections of brain tissues from each group were stained with immunohistochemistry method.

RESULTThe expression of RAG-1 persisted from E11 to P0 brain and was steadily increased from E11 to E19; the results of RT-PCR were similar to that of immunohistochemistry. The positive-cells mainly appeared in the nucleus amygdalae, hypothalamus, thalamus and hippocampus at developmental stage. The expression began to appear in ventricular zone (VZ) and intermediate zone (IZ) of telecephalic vesicle, then gradually increased in subventricular zone (SVZ), corticle plate (CP) and subcorticle plate (SP).

CONCLUSIONThe expression of RAG-1 in mouse embryonic brain tissue is higher than that in the adult mouse, which may be related to the process of neuron development.

Animals ; Brain ; cytology ; embryology ; metabolism ; Female ; Gene Expression Regulation, Developmental ; Homeodomain Proteins ; genetics ; metabolism ; Immunohistochemistry ; Mice ; Mice, Inbred ICR ; Neurons ; cytology ; metabolism ; Pregnancy ; Reverse Transcriptase Polymerase Chain Reaction ; Time Factors