Prenatal diagnosis of two fetuses with deletions of 8p23.1, critical region for congenital diaphragmatic hernia and heart defects.

Microdeletions of 8p23.1 are mediated by low copy repeats and can cause congenital diaphragmatic hernia (CDH) and cardiac defects. Within this region, point mutations of the GATA4 gene have been shown to cause cardiac defects. However, the cause of CDH in these deletions has been difficult to determine due to the paucity of mutations that result in CDH, the lack of smaller deletions to refine the region and the reduced penetrance of CDH in these large deletions. Mice deficient for one copy of the Gata4 gene have been described with CDH and heart defects suggesting mutations in Gata4 can cause the phenotype in mice. We report on the SNP microarray analysis on two fetuses with deletions of 8p23.1. The first had CDH and a ventricular septal defect (VSD) on ultrasonography and a family history of a maternal VSD. Microarray analysis detected a 127-kb deletion which included the GATA4 and NEIL2 genes which was inherited from the mother. The second fetus had an incomplete atrioventricular canal defect on ultrasonography. Microarray analysis showed a 315-kb deletion that included seven genes, GATA4, NEIL2, FDFT1, CTSB, DEFB136, DEFB135, and DEFB134. These results suggest that haploinsufficiency of the two genes in common within 8p23.1; GATA4 and NEIL2 can cause CDH and cardiac defects in humans.

Selective induction of matrix metalloproteinases by Borrelia burgdorferi via toll-like receptor 2 in monocytes.

Regulation of secretion of matrix metalloproteinase (MMP) underlies the basis of numerous physiological and pathological processes in multicellular organisms. The Toll receptor family, which is conserved from Drosophila species to humans, mediates pattern recognition of a diversity of ligands involved in morphogenesis and innate immunity. Here, we show that secretion of MMP-9 is selectively induced through Toll-like receptor (TLR) 2 in human and murine monocytic cells stimulated with Borrelia burgdorferi. Secretion of MMP-1 was shown to be stimulated through a pathway other than TLR2, under identical conditions. Analysis of nuclear extracts indicated that activator protein (AP)-1 was reduced in TLR2-neutralized monocytic cells, suggesting that AP-1 plays a role in the transcriptional activation of MMP-9 through TLR2. The specific induction of MMP-9 through TLR2 provides direct evidence of a new role for this ancient receptor family in regulating secretion of MMPs and demonstrates evolutionary convergence between invertebrate morphogenesis and the vertebrate innate immune system.