Anti-HAND1 monoclonal antibody, clone 9F8B22,9D3G5

In mice the transcription factor Elf5 is necessary for correct trophoblast development. Upon knockdown of Elf5, TS cells display neither a decrease in proliferation nor an increase in cell death but rather an increased propensity to differentiate. Such cells rapidly lose Sox2 and 3 expression, while transiently upregulating the giant cell differentiation determinant gene Hand1. Other genes affected within 24 h of Elf5 knock-down, many of which have not previously been implicated in trophoblast development, exhibited in vivo expression domains and in vitro expression responses consistent with Elf5 having a role in counteracting trophoblast differentiation. In an ES to TS differentiation assay using Cdx2 overexpression with Elf5 loss of function cell lines, it was shown that Elf5 is necessary to prevent terminal trophoblast differentiation. This data thus suggest that Elf5 is a gatekeeper for the TS to differentiated trophoblast transition thereby preventing the precocious differentiation of the undifferentiated extraembryonic ectoderm. (C) 2014 Elsevier Inc. All rights reserved.

Germline mutations in cardiac-specific transcription factor genes have been associated with congenital heart disease (CHD) and the homeodomain transcription factor NKX2-5 is an important member of this group. Indeed, more than 40 heterozygous NKX2-5 germline mutations have been observed in individuals with CHD, and these are spread along the coding region, with many shown to impact protein function. In pursuit of understanding causes of CHD, we analyzed n = 49 cardiac biopsies from 28 patients and identified by direct sequencing two nonsynonymous NKX2-5 alterations affecting alanine 119, namely c.356C>A (p.A119E) and c.355G>T, (p.A119S), in patients with AVSD and HLHS, respectively. In functional assays, a significant reduction in transcriptional activities could be determined for the NKX2-5 variants. Importantly, in one family the mother, besides p.A119E, carried a synonymous mutant allele in the homeodomain (c.543G>A, p.Q181), and a synonymous dbSNP (c.63A>G, p.E21) in the transactivation domain of the protein, that were transmitted to the CHD daughter. The presence of these variants in-cis with the p.A119E mutation led to a further reduction in transcriptional activities. Such difference in activity may be in part related to reduced protein expression for the double variant c.356C>A and c.543G>A. We propose changes in mRNA stability and folding, due to a silent mutation and a dbSNP in the NKX2-5 coding region to contribute to the functional defect. Although the clinical significance of the NKX2-5 haplotype identified in the CHD patients remains to be ascertained, we provide evidence of an interaction of a dbSNP, with synonymous and nonsynonymous mutations to negatively impact NKX2-5 transcriptional activity.