Nuclear factor I isoforms regulate gene expression during the differentiation of human neural progenitors to astrocytes.
Even though astrocytes are critical for both normal brain functions and the development and progression of neuropathological states, including neuroinflammation associated with neurodegenerative diseases, the mechanisms controlling gene expression during astrocyte differentiation are poorly understood. Thus far, several signaling pathways were shown to regulate astrocyte differentiation, including JAK-STAT, bone morphogenic protein-2/Smads, and Notch. More recently, a family of nuclear factor-1 (NFI-A, -B, -C, and -X) was implicated in the regulation of vertebral neocortex development, with NFI-A and -B controlling the onset of gliogenesis. Here, we developed an in vitro model of differentiation of stem cells towards neural progenitors (NP) and subsequently astrocytes. The transition from stem cells to progenitors was accompanied by an expected change in the expression profile of markers, including Sox-2, Musashi-1, and Oct4. Subsequently, generated astrocytes were characterized by proper morphology, increased glutamate uptake, and marker gene expression. We used this in vitro differentiation model to study the expression and functions of NFIs. Interestingly, stem cells expressed only background levels of NFIs, while differentiation to NP activated the expression of NFI-A. More importantly, NFI-X expression was induced during the later stages of differentiation towards astrocytes. In addition, NFI-X and -C were required for the expression of glial fibrillary acidic protein and secreted protein acidic and rich in cystein-like protein 1, which are the markers of astrocytes at the later stages of differentiation. We conclude that an expression program of NFIs is executed during the differentiation of astrocytes, with NFI-X and -C controlling the expression of astrocytic markers at late stages of differentiation.
Department of Biochemistry and Molecular Biology, Massey Cancer Center, Virginia Commonwealth University, Richmond, VA 23298, USA.
Katarzyna M
KM
Wilczynska
Sandeep K
SK
Singh
Bret
B
Adams
Lauren
L
Bryan
Raj R
RR
Rao
Kristoffer
K
Valerie
Sarah
S
Wright
Irene
I
Griswold-Prenner
Tomasz
T
Kordula
D000818:Animals; D001253:Astrocytes / Q000166:cytology* / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000378:metabolism; D002454:Cell Differentiation / Q000235:genetics*; D002460:Cell Line; D016326:Extracellular Matrix Proteins / Q000378:metabolism; D005786:Gene Expression Regulation; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D006801:Humans; D051379:Mice; D008954:Models, Biological; D051839:NFI Transcription Factors / Q000235:genetics / Q000378:metabolism*; D009474:Neurons / Q000166:cytology* / Q000378:metabolism; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism
D002135:Calcium-Binding Proteins; D016326:Extracellular Matrix Proteins; D005904:Glial Fibrillary Acidic Protein; D051839:NFI Transcription Factors; D020033:Protein Isoforms; C503126:SPARCL1 protein, human