Mouse Anti Rat Nkx6.1 Hybridoma [G66B21]

Pancreatic development in mammals is controlled in part by the expression and function of numerous genes encoding transcription factors. Yet, how these regulate each other and their target genes is incompletely understood. Embryonic stem (ES) cells have recently been shown to be capable of differentiating into pancreatic progenitor cells and insulin-producing cells, representing a useful in vitro model system for studying pancreatic and islet development. To generate tools to study the relationships of transcription factors in pancreatic development we have established seven unique mouse ES cell lines with tetracycline-inducible expression of either Hnf4 alpha, Hnf6, Nkx2.2, Nkx6.1, Pax4, Pdx1, and Ptf1a cDNAs. Each of the cell lines was characterized for induction of transgene expression after exposure to doxycycline (DOX) by quantitative real-time PCR and immunofluorescence microscopy. Transgene expression in the presence of DOX was at least 97-fold that seen in untreated cells. Immunofluorescent staining of DOX-treated cultures showed efficient (> 95% of cells) transgene protein expression while showing < 5% positive staining in uninduced cells. Each of the ES cell lines maintained their pluripotency as measured by teratoma formation. Furthermore, transgene expression can be efficiently achieved in vivo through DOX administration to mice. The establishment of ES cell lines with temporally controllable induction of critical pancreatic transcription factor genes provides a new set of tools that could be used to interrogate gene regulatory networks in pancreatic development and potentially generate greater numbers of ss cells from ES cells.

Genome-wide association studies have revealed > 60 loci associated with type 2 diabetes ( T2D), but the underlying causal variants and functional mechanisms remain largely elusive. Although variants in TCF7L2 confer the strongest risk of T2D among common variants by presumed effects on islet function, the molecular mechanisms are not yet well understood. Using RNA-sequencing, we have identified a TCF7L2-regulated transcriptional network responsible for its effect on insulin secretion in rodent and human pancreatic islets. ISL1 is a primary target of TCF7L2 and regulates proinsulin production and processing via MAFA, PDX1, NKX6.1, PCSK1, PCSK2 and SLC30A8, thereby providing evidence for a coordinated regulation of insulin production and processing. The risk T-allele of rs7903146 was associated with increased TCF7L2 expression, and decreased insulin content and secretion. Using gene expression profiles of 66 human pancreatic islets donors', we also show that the identified TCF7L2-ISL1 transcriptional network is regulated in a genotype-dependent manner. Taken together, these results demonstrate that not only synthesis of proinsulin is regulated by TCF7L2 but also processing and possibly clearance of proinsulin and insulin. These multiple targets in key pathways may explain why TCF7L2 has emerged as the gene showing one of the strongest associations with T2D.