Biomedical subjects

Fiona Broackes-Carter

Publications and source records attributed to Fiona Broackes-Carter.

3 recordsLinked to original sources

PubMed2005

Arylamine N-acetyltransferase 2 expression in the developing heart.

Murine arylamine N-acetyltransferase 2 (NAT2) is expressed in the developing heart and in the neural tube at the time of closure. Classically described as a xenobiotic metabolizing enzyme, there is increasing evidence for a distinct biological role for murine NAT2. We have characterized the expression of arylamine N-acetyltransferase 2 during cardiogenesis, mapping its expression in vivo, using a lacZ insertion deletion, and also in vitro, by measuring NAT2 enzyme activity. These findings show that cardiac Nat2 expression is both temporally and spatially regulated during development. In neonatal mice, cardiac Nat2 expression is most extensive in the central fibrous body and is evident in the atrioventricular valves and the valves of the great vessels. Whereas Nat2 expression is not detected in ventricular myocardial cells, Nat2 is strongly expressed in scattered cells in the region of the sinus node, the epicardium of the right atrial appendage, and in the pulmonary artery. Expression of active NAT2 protein is maximal when the developing heart attains the adult circulation pattern and moves from metabolizing glucose to fatty acids. NAT2 acetylating activity in cardiac tissue from Nat2(-/-) and Nat2(+/-) mice indicates a lack of compensating acetylating activity either from other acetylating enzymes or by NAT2 encoded by the wild-type Nat2 allele in Nat2(+/-) heterozygotes. The temporal and spatial control of murine Nat2 expression points to an endogenous role distinct from xenobiotic metabolism and indicates that Nat2 expression may be useful as a marker in cardiac development.

Acetylation↗

PubMed2004

Quantitative methods for the analysis of CFTR transcripts/splicing variants.

In cystic fibrosis (CF), transcript analysis and quantification are important for diagnosis, prognosis and also as surrogate markers for some therapies including gene therapy. Classical RNA-based methods require significant expression levels in target samples for appropriate analysis, thus PCR-based methods are evolving towards reliable quantification. Various protocols for the quantitative analysis of CFTR transcripts (including those resulting from splicing variants) are described and discussed here.

Cystic Fibrosis↗

PubMed2003

Alternative 5' exons of the CFTR gene show developmental regulation.

The cystic fibrosis transmembrane conductance regulator (CFTR) gene shows a complex mechanism of tissue-specific and temporal regulation. Expression of the sheep and human CFTR genes shows a gradual decline during lung development, from the early mid-trimester through to term. Alternative upstream exons of CFTR have been identified in several species but their functional role remains obscure. We identified a novel 5' exon of the sheep CFTR gene (ov1a) that occurs in two splice forms (ov1aL and ov1aS), which are both mutually exclusive with exon 1. CFTR transcripts including ov1aL and ov1aS are present at low levels in many sheep tissues, however ov1aS shows temporal and spatial regulation during fetal lung development, being most abundant when CFTR expression levels start to decline. Alternative 5' exons -1a and 1a in the human CFTR gene also show changes in expression levels through lung development. Evaluation of ov1aL and ov1aS by Mfold reveals the potential to form extremely stable secondary structures which would cause ribosomal subunit detachment. Further, the loss of exon 1 from the CFTR transcript removes motifs that are crucial for normal trafficking of the CFTR protein. Recruitment of these alternative upstream exons may represent a novel mechanism of developmental regulation of CFTR expression.

Alternative Splicing↗