ABSTRACT
We have investigated the effects of tCFA15, a non-peptidic compound, on the differentiation of neural stem cell-derived neurospheres, and have found that tCFA15 promotes their differentiation into neurons and reduces their differentiation into astrocytes, in a dose-dependent manner. This response is reminiscent of that resulting from the loss-of-function of Notch signaling after inactivation of the Delta-like 1 (Dll1) gene. Further analysis of the expression of genes from the Notch pathway by reverse transcriptase-PCR revealed that tCFA15 treatment results in a consistent decrease in the level of Notch1 mRNA. We have confirmed this result in other cell lines and propose that it reflects a general effect of the tCFA15 molecule. We discuss the implications of this finding with respect to regulation of Notch activity in neural stem cells, and the possible use of tCFA15 as a therapeutic tool for various pathologies that result from impairment of Notch signaling.
Subject(s)
Cell Differentiation/drug effects , Cyclohexanones/pharmacology , Fatty Alcohols/pharmacology , Neural Stem Cells/cytology , Neural Stem Cells/drug effects , Receptor, Notch1/metabolism , Animals , Astrocytes/cytology , Astrocytes/drug effects , Gene Expression Regulation/drug effects , Mice , Neural Stem Cells/metabolism , Neurons/cytology , Neurons/drug effects , RNA, Messenger/genetics , RNA, Messenger/metabolism , Receptor, Notch1/geneticsABSTRACT
Neural stem cells cultured as neurospheres were used to assess the effects of P. notoginseng on the production of neurons and glia. The crude saponins (PNS) and ginsenoside-Rd promote the differentiation of neurospheres into astrocytes. Ginsenoside-Rd increases the production of astrocytes in a dose-dependent manner. On the other hand, both PNS and ginsenoside-Rd induce a weak but significant effect by decreasing the number of neurons. The other ginsenosides do not induce any differentiation on both neurons and astrocytes.
Subject(s)
Astrocytes/drug effects , Cell Differentiation/drug effects , Ginsenosides/pharmacology , Neurons/cytology , Stem Cells/drug effects , Animals , Astrocytes/cytology , Cells, Cultured , Mice , Panax/chemistry , Stem Cells/cytologyABSTRACT
In a search for inducers of neuronal differentiation to treat neurodegenerative diseases such as Alzheimer's disease, a series of indole fatty alcohols (IFAs) were prepared. 13c (n = 18) was able to promote the differentiation of neural stem cell derived neurospheres into neurons at a concentration of 10 nM. Analysis of the expression of the Notch pathway genes in neurospheres treated during the differentiation phase with 13c (n = 18) revealed a significant decrease in the transcription of the Notch 4 receptor.
Subject(s)
Alcohols/chemical synthesis , Fatty Alcohols/chemical synthesis , Free Radical Scavengers/chemical synthesis , Indoles/chemical synthesis , Neurons/drug effects , Stem Cells/drug effects , Alcohols/chemistry , Alcohols/pharmacology , Animals , Benzothiazoles , Cell Differentiation/drug effects , Fatty Alcohols/chemistry , Fatty Alcohols/pharmacology , Free Radical Scavengers/chemistry , Free Radical Scavengers/pharmacology , Free Radicals/chemistry , In Vitro Techniques , Indoles/chemistry , Indoles/pharmacology , Membrane Proteins/genetics , Membrane Proteins/physiology , Mice , Neurons/cytology , Oligonucleotides, Antisense/pharmacology , Proto-Oncogene Proteins/biosynthesis , Proto-Oncogene Proteins/genetics , Receptor, Notch1 , Receptor, Notch2 , Receptor, Notch4 , Receptors, Cell Surface/biosynthesis , Receptors, Cell Surface/genetics , Receptors, Notch , Reverse Transcriptase Polymerase Chain Reaction , Stem Cells/cytology , Structure-Activity Relationship , Sulfonic Acids/chemistry , Transcription Factors/biosynthesis , Transcription Factors/genetics , Transcription, GeneticABSTRACT
We examined the role of Notch signaling on the generation of neurons and glia from neural stem cells by using neurospheres that are clonally derived from neural stem cells. Neurospheres prepared from Dll1(lacZ/lacZ) mutant embryos segregate more neurons at the expense of both oligodendrocytes and astrocytes. This mutant phenotype could be rescued when Dll1(lacZ/lacZ) spheres were grown and/or differentiated in the presence of conditioned medium from wild-type neurospheres. Temporal modulation of Notch by soluble forms of ligands indicates that Notch signaling acts in two steps. Initially, it inhibits the neuronal fate while promoting the glial cell fate. In a second step, Notch promotes the differentiation of astrocytes, while inhibiting the differentiation of both neurons and oligodendrocytes.
