Rabbit Anti-EGR1 Polyclonal antibody

The low efficiency of in vitro differentiation of human embryonic stem cells (hESCs) or human-induced pluripotent stem cells (iPSCs) into insulin-producing cells is a crucial hurdle for the clinical implementation of human pluripotent stem cells (PSCs). Our previous investigation into the key factors for the differentiation of PSCs into insulin-producing cells suggested that the expression of GATA binding protein 6 (GATA6) and Gremlin 1 (GREM1) and inhibition of early growth response protein 1 (Egr1) may be important factors. In this study, we investigated the role of Egr1 in pancreas development. The transfection of small interfering RNA (siRNA) of Egr1 in the early phase induced the differentiation of iPSCs derived from fibroblasts (FiPSCs) into pancreatic endoderm and insulin-producing cells. In contrast, the downregulation of Egr1 in the late phase suppressed the differentiation of FiPSCs into pancreatic endoderm and insulin-producing cells. In addition, the overexpression of Egr1 suppressed the differentiation of iPSCs derived from pancreatic cells into pancreatic endoderm and insulin-producing cells. These data suggest that the downregulation of Egr1 in the early phase can efficiently induce the differentiation of iPSCs into insulin-producing cells.

Simple Summary: Bone morphogenetic protein 7 (BMP7) is one of the largest secretory signal conductive molecules and is in the TGF-beta superfamily. It plays an important role in the growth and development of hair follicles. We cloned the proximal promoter of the BMP7 gene for bioinformatics analysis. Dual-luciferase reporter system and overexpression were used to analyze the key regions and transcription factor binding sites. There was high activity between -758 bp and -545 bp in the core region of the gene and a possible binding site for transcription factors SP1 and EGR1. Abstract: The BMP7 gene is involved in the growth and development of hair follicles but its regulation mechanism is unclear. We studied the regulation mechanism of the BMP7 promoter by cloning the proximal promoter of BMP7 for bioinformatics analysis. A series of missing vectors was then constructed for dual-fluorescein activity detection based on the bioinformatics analysis results. We tested transcription-factor binding-site mutations and transcription factor over-expression to analyze the transcriptional regulation principle of the BMP7 promoter region. The upstream transcriptional regulatory region of the BMP7 gene proximal promoter was predicted by bioinformatics. There were -1216 bp to -1166 bp and -632 bp to -582 bp transcription initiation sites in the upstream transcriptional regulatory region of the BMP7 gene proximal promoter. The CpG islands' distribution showed that there were many CpG islands at -549 bp to 1 bp. A dual-luciferase assay revealed high activity between -758 bp and -545 bp in the core region and a possible binding site for transcription factors SP1 and EGR1. The transcriptional activity of BMP7 was significantly decreased in the transcriptional regulatory region of the BMP7 after EGR1 and SP1 mutation. Transcription was significantly enhanced by over expression of the EGR1 transcription factor, which strongly suggests that EGR1 and SP1 play important roles in BMP7 regulation.