TAZ Induction Directs Differentiation of Thyroid Follicular Cells from Human Embryonic Stem Cells.
The differentiation program for human thyroid follicular cells (TFCs) relies on the interplay between sequence-specific transcription factors and transcriptional co-regulators. Transcriptional co-activator with PDZ-binding motif (TAZ) is a co-activator that regulates several transcription factors, including PAX8 and NKX2-1, which play a central role in thyroid-specific gene transcription. TAZ and PAX8/NKX2-1 are co-expressed in the nuclei of thyroid cells, and TAZ interacts directly with both PAX8 and NKX2-1, leading to their enhanced transcriptional activity on the thyroglobulin (TG) promoter and additional genes.



The use of a small molecule, ethacridine, recently identified as a TAZ activator, in the differentiation of thyroid cells from human embryonic stem (hES) cells was studied. First, endodermal cells were derived from hES cells using Activin A, followed by induction of differentiation into thyroid cells directed by ethacridine and thyrotropin (TSH).



The expression of TAZ was increased in the Activin A-derived endodermal cells by ethacridine in a dose-dependent manner and followed by increases in PAX8 and NKX2-1 when assessed by both quantitative polymerase chain reaction and immunostaining. Following further differentiation with the combination of ethacridine and TSH, the thyroid-specific genes TG, TPO, TSHR, and NIS were all induced in the differentiated hES cells. When these cells were cultured with extracellular matrix-coated dishes, thyroid follicle formation and abundant TG protein expression were observed. Furthermore, such hES cell-derived thyroid follicles showed a marked TSH-induced and dose-dependent increase in radioiodine uptake and protein-bound iodine accumulation.



These data show that fully functional human thyroid cells can be derived from hES cells using ethacridine, a TAZ activator, which induces thyroid-specific gene expression and promotes thyroid cell differentiation from the hES cells. These studies again demonstrate the importance of transcriptional regulation in thyroid cell development. This approach also yields functional human thyrocytes, without any gene transfection or complex culture conditions, by directly manipulating the transcriptional machinery without interfering with intermediate signaling events.
Thyroid Research Unit, Department of Medicine, The Icahn School of Medicine at Mount Sinai, Mount Sinai Beth Israel Medical Center and the James J. Peters VA Medical Center , New York, New York.
Risheng
R
Ma
Thyroid Research Unit, Department of Medicine, The Icahn School of Medicine at Mount Sinai, Mount Sinai Beth Israel Medical Center and the James J. Peters VA Medical Center , New York, New York.
Syed A
SA
Morshed
Thyroid Research Unit, Department of Medicine, The Icahn School of Medicine at Mount Sinai, Mount Sinai Beth Israel Medical Center and the James J. Peters VA Medical Center , New York, New York.
Rauf
R
Latif
Thyroid Research Unit, Department of Medicine, The Icahn School of Medicine at Mount Sinai, Mount Sinai Beth Israel Medical Center and the James J. Peters VA Medical Center , New York, New York.
Terry F
TF
Davies
D028341:Activins / Q000494:pharmacology; D001324:Autoantigens / Q000187:drug effects / Q000235:genetics; D002454:Cell Differentiation / Q000187:drug effects* / Q000235:genetics; D004975:Ethacridine / Q000494:pharmacology*; D000066449:Human Embryonic Stem Cells / Q000166:cytology / Q000187:drug effects*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000187:drug effects* / Q000235:genetics; D007453:Iodide Peroxidase / Q000187:drug effects / Q000235:genetics; D033862:Iron-Binding Proteins / Q000187:drug effects / Q000235:genetics; D000072636:PAX8 Transcription Factor / Q000187:drug effects / Q000235:genetics; D011989:Receptors, Thyrotropin / Q000187:drug effects / Q000235:genetics; D027981:Symporters / Q000187:drug effects / Q000235:genetics; D013954:Thyroglobulin / Q000187:drug effects / Q000235:genetics; D000072637:Thyroid Epithelial Cells / Q000166:cytology / Q000187:drug effects*; D000074482:Thyroid Nuclear Factor 1 / Q000187:drug effects / Q000235:genetics; D013972:Thyrotropin / Q000494:pharmacology*; D015534:Trans-Activators; D014157:Transcription Factors; D000091364:Transcriptional Coactivator with PDZ-Binding Motif Proteins; D000099209:Sodium-Iodide Symporters
D028341:Activins; D001324:Autoantigens; D004975:Ethacridine; D047908:Intracellular Signaling Peptides and Proteins; D007453:Iodide Peroxidase; D033862:Iron-Binding Proteins; D000072636:PAX8 Transcription Factor; D011989:Receptors, Thyrotropin; D027981:Symporters; D013954:Thyroglobulin; D000074482:Thyroid Nuclear Factor 1; D013972:Thyrotropin; D015534:Trans-Activators; D014157:Transcription Factors; D000091364:Transcriptional Coactivator with PDZ-Binding Motif Proteins; D000099209:Sodium-Iodide Symporters; C000614412:NKX2-1 protein, human; C083325:PAX8 protein, human; C551991:WWTR1 protein, human; C422405:activin A; C056658:TPO protein, human
NK2 homeobox 1 (NKX2-1); Paired box gene 8 (PAX8); ethacridine; human embryonic stem cells; thyroid follicular cells; transcriptional co-activator with PDZ-binding motif (TAZ)