Fine mapping and single nucleotide polymorphism association results of candidate genes for asthma and related phenotypes
HUMAN MUTATION
Authors: Immervoll, T; Loesgen, S; Dutsch, G; Gohlke, H; Herbon, N; Klugbauer, S; Dempfle, A; Bickeboller, H; Becker-Follmann, J; Ruschendorf, F; Saar, K; Reis, A; Wichmann, HE; Wjst, M
Abstract
Several genome,wide screens for asthma and related phenotypes have been published to date but data on fine,mapping are scarce. For higher resolution we performed a fine-mapping study with 2 cM average spacing in often discussed asthma candidate regions (2p, 5q, 6p, 7p, 9q, 11p, and 12q) to narrow down the regions of interest. All participants of a Caucasian family study (97 families with at least two affected sib pairs) were genotyped for 49 supplementary polymorphic dinucleotide markers. Our results indicate increased evidence for linkage on chromosome 6p, 9q, and 12q. These candidate regions were further analyzed with SNP polymorphisms in the endothelin 1 (EDN1), lymphotoxin alpha (LTA), and neuronal nitric oxide synthase (NOS 1) genes. In addition, IL4-590C>T and IL10-592C>A, localized on chromosomes 5q and 1q, respectively, have been analyzed for SNP association. Of the six SNPs tested, four revealed weak association with the examined phenotypes. These are the IL10-592C>A SNP in the interleukin 10 gene (p=0.036 for eosinophil cell counts), the 4124T>C SNP in EDN1 (p=0.044 for asthma), the 3391C>T SNP in NOS I with eosinophil cell counts (p=0.0086), and the 5266C>T polymorphism, also in the NOS1 gene, for high IgE levels (p=0.022). In summary, fine mapping data enable us to cone fine asthma candidate regions, while variants of EDN1 and NOS1, or nearby genes, may play an important role in this context. Hum Mutat 18:327-336, 2001. (C) 2001 Wiley-Liss, Inc.
Cellular localization, expression and functional implications of the utero-placental endothelin system during maintenance and termination of canine gestation
JOURNAL OF REPRODUCTION AND DEVELOPMENT
Authors: Gram, Aykut; Boos, Alois; Kowalewski, Mariusz P.
Abstract
Utero-placental (Ut-Pl) angiogenesis and blood flow are fundamental for successful outcome of pregnancy. They are controlled by numerous vasodilator and vasoconstrictor systems such as endothelins (EDNs) and the renin angiotensin system. Dogs possess an invasive type of placentation, classified as endotheliochorial. Despite increasing knowledge regarding canine Ut-P1 function, little information exists on uterine and placental vascular activity during initiation, maintenance and termination of pregnancy in this species. The current study investigated expression of EDNs and their receptors (EDNRA and EDNRB) in the pre-implantation uterus and Ut-P1 compartments during gestation and at normal parturition, as well as in mid pregnant dogs treated with the antigestagen aglepristone. The Ut-Pl mRNA expression of EDNI and EDNRA was constant until mid-gestation and increased significantly during prepartum luteolysis. In contrast, EDN2 was highest pre-implantation and decreased following placentation, remaining low thereafter. Expression of the EDN-activating enzyme ECE1 and mRNA of EDNRB increased towards mid-gestation and was further elevated at prepartum luteolysis. Antigestagen treatment resulted in increased levels of EDNI and EDNRA. At the cellular level, the uterine expression of EDN1, ECE1 and EDNRB was found predominantly in the endometrial surface and glandular epithelial cells; uterine signals for EDNRA were weak. In Ut-P1 all targets were mainly localized in the placenta fetalis, with syncytiotrophoblast staining stronger for ECE1 and EDNRB. In contrast, EDNRA stained strongly at the base of the placental labyrinth. Expression and localization of EDNs (EDN1, -2), EDN receptors and ECE1 in the placenta fetalis suggests their involvement in the trophoblast invasion and proliferation.