scholarly journals Potential Role of Activating Transcription Factor 5 during Osteogenesis

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Luisa Vicari ◽  
Giovanna Calabrese ◽  
Stefano Forte ◽  
Raffaella Giuffrida ◽  
Cristina Colarossi ◽  
...  
Keyword(s):  
Stem Cells ◽  
Transcription Factor ◽  
Osteogenic Differentiation ◽  
Potential Role ◽  
Bone Mineralization ◽  
Human Adipose Tissue ◽  
Camp Response Element Binding ◽  
Adipose Derived Stem Cells ◽  
Element Binding Protein ◽  
Activating Transcription Factor

Human adipose-derived stem cells are an abundant population of stem cells readily isolated from human adipose tissue that can differentiate into connective tissue lineages including bone, cartilage, fat, and muscle. Activating transcription factor 5 is a transcription factor of the ATF/cAMP response element-binding protein (CREB) family. It is transcribed in two types of mRNAs (activating transcription factor 5 isoform 1 and activating transcription factor 5 isoform 2), encoding the same single 30-kDa protein. Although it is well demonstrated that it regulates the proliferation, differentiation, and apoptosis, little is known about its potential role in osteogenic differentiation. The aim of this study was to evaluate the expression levels of the two isoforms and protein during osteogenic differentiation of human adipose-derived stem cells. Our data indicate that activating transcription factor 5 is differentially expressed reaching a peak of expression at the stage of bone mineralization. These findings suggest that activating transcription factor 5 could play an interesting regulatory role during osteogenesis, which would provide a powerful tool to study bone physiology.

Osteogenic Differentiation of Human Adipose Tissue-Derived Stem Cells Is Modulated by the miR-26a Targeting of the SMAD1 Transcription Factor

2007 ◽  
Vol 23 (2) ◽  
pp. 287-295 ◽  
Author(s):  
Ettore Luzi ◽  
Francesca Marini ◽  
Silvia Carbonell Sala ◽  
Isabella Tognarini ◽  
Gianna Galli ◽  
...  
Keyword(s):  
Stem Cells ◽  
Transcription Factor ◽  
Adipose Tissue ◽  
Osteogenic Differentiation ◽  
Human Adipose Tissue

scholarly journals Drosophila Activating Transcription Factor-2 Is Involved in Stress Response via Activation by p38, but Not c-Jun NH2-Terminal Kinase

2005 ◽  
Vol 16 (6) ◽  
pp. 2934-2946 ◽  
Author(s):  
Yuji Sano ◽  
Hiroshi Akimaru ◽  
Tomoo Okamura ◽  
Tomoko Nagao ◽  
Masahiro Okada ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Stress Response ◽  
Osmotic Stress ◽  
Camp Response Element Binding ◽  
Dominant Negative ◽  
Camp Response Element ◽  
Double Stranded Rna ◽  
Element Binding Protein ◽  
Activating Transcription Factor

Activating transcription factor (ATF)-2 is a member of the ATF/cAMP response element-binding protein family of transcription factors, and its trans-activating capacity is enhanced by stress-activated protein kinases such as c-Jun NH2-terminal kinase (JNK) and p38. However, little is known about the in vivo roles played by ATF-2. Here, we identified the Drosophila homologue of ATF-2 (dATF-2) consisting of 381 amino acids. In response to UV irradiation and osmotic stress, Drosophila p38 (dp38), but not JNK, phosphorylates dATF-2 and enhances dATF-2-dependent transcription. Consistent with this, injection of dATF-2 double-stranded RNA (dsRNA) into embryos did not induce the dorsal closure defects that are commonly observed in the Drosophila JNK mutant. Furthermore, expression of the dominant-negative dp38 enhanced the aberrant wing phenotype caused by expression of a dominant-negative dATF-2. Similar genetic interactions between dATF-2 and the dMEKK1-dp38 signaling pathway also were observed in the osmotic stress-induced lethality of embryos. Loss of dATF-2 in Drosophila S2 cells by using dsRNA abrogated the induction of 40% of the osmotic stress-induced genes, including multiple immune response-related genes. This indicates that dATF-2 is a major transcriptional factor in stress-induced transcription. Thus, dATF-2 is critical for the p38-mediated stress response.

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