Sign up for Table of Contents Alerts.
Email this page
Print this page
Research Paper
Developmental Expression of Wnt Signaling Factors in Mouse Brain
Jacquelyn Coyle-Rink, Luis Del Valle, Thersa Sweet, Kamel Khalili and Shohreh Amini
volume 1 | issue 6
november/december 2002Pages: 640-645
We now provide open access to journal articles published online for one year or more. This article may be downloaded at the following link:
Download PDFIf the document does not open, please right-click on the link (control-click on a Macintosh) and select the option to save the file to disk.
The Wnt signaling pathway has been implicated in a variety of biological events inducing neurogenesis. In this study, we aim to investigate the expression pattern of various components of the Wnt pathway including b-catenin and its partners LEF-1/TCF-4, GSK-3b and their nuclear target genes such as c-myc and cyclin D1 during mouse brain development. We performed a series of Western blot and immunohistochemistry of brain cortex, brainstem, and cerebellum which revealed differential accumulation of these proteins in different types of brain cells including neurons, astrocytes, and oligodendrocytes at different developmental stages. Intense cytoplasmic immunolabeling of b-catenin in 5 day old neurons throughout the cortex and brainstem significantly decreased as the brain developed, whereas the level of GSK-3b, the protein that phosphorylates b-catenin and causes its destabilization, increased during brain maturation. On the other hand, high level accumulation of LEF-1 and TCF-4 in neurons and astrocytes at the early stage of brain development diminished at the later stages. Interestingly, while the majority of LEF-1 and TCF-4 immunoreactivity was detected in the cytoplasm of neurons, it was evident that both proteins accumulated in the nuclei of astrocytes. Examination of cyclin D1, a protein that controls the cell cycle and proliferation, exhibited an intense staining in the nuclei of astrocytes throughout brain parenchyma during development. Interestingly, cyclin D was found in the cytoplasm of neurons from cortex, brainstem, and cerebellum during brain development. These data provide compelling evidence for the differential expression of the Wnt signaling pathway during brain development, and suggest that these signaling pathways may function differently in various brain regions and cell types.
We now provide open access to journal articles published online for one year or more. This article may be downloaded at the following link:
Download PDFIf the document does not open, please right-click on the link (control-click on a Macintosh) and select the option to save the file to disk.