HTR4 gene structure and altered expression in the developing lung

• Published in: Respiratory research 2013-07, Vol.14 (1), p.77-77, Article 77
• Main Authors: Hodge, Emily, Nelson, Carl P, Miller, Suzanne, Billington, Charlotte K, Stewart, Ceri E, Swan, Caroline, Malarstig, Anders, Henry, Amanda P, Gowland, Catherine, Melén, Erik, Hall, Ian P, Sayers, Ian
• Format: Article
• Language: English
• Subjects: Alveoli; Analysis; Chronic obstructive pulmonary disease; DNA binding proteins; DNA microarrays; Female; Gene expression; Gene Expression Regulation, Developmental - genetics; Genes; Genetic aspects; Genetic research; Genomes; Humans; Immunohistochemistry; Klinisk medicin; Lung - embryology; Lung - physiology; Lung diseases, Obstructive; Lungmedicin och allergi; Lungs; Male; Medicin och hälsovetenskap; Medicinsk genetik; Medicinska och farmaceutiska grundvetenskaper; Messenger RNA; Muscular system; Physiological aspects; Receptors, Serotonin - genetics; Respiratory function; Rodents; Single nucleotide polymorphisms; Studies
• ISSN: 1465-993X; 1465-9921; 1465-993X; 1465-9921
• DOI: 10.1186/1465-9921-14-77

Meta-analyses of genome-wide association studies (GWAS) have identified single nucleotide polymorphisms (SNPs) spanning the 5-hydroxytryptamine receptor 4 (5-HT₄R) gene (HTR4) associated with lung function. The aims of this study were to i) investigate the expression profile of HTR4 in adult and fetal lung tissue and cultured airway cells, ii) further define HTR4 gene structure and iii) explore the potential functional implications of key SNPs using a bioinformatic approach. Following reverse transcription (RT)-PCR in human brain, 5' rapid amplification of cDNA ends (5' RACE) was used to examine the exonic structure of HTR4 at the 5' end. Quantitative (Q)-PCR was used to quantify HTR4 mRNA expression in total RNA from cultured airway cells and whole lung tissue. Publically available gene microarray data on fetal samples of estimated gestational age 7-22 weeks were mined for HTR4 expression. Immunohistochemistry (IHC; in adult and fetal lung tissue) and a radioligand binding assay (in cultured airway cells) were used to analyze 5-HT₄R protein expression. IHC in adult lung, irrespective of the presence of chronic obstructive pulmonary disease (COPD), suggested low level expression of 5-HT₄R protein, which was most prominent in alveolar pneumocytes. There was evidence of differential 5-HT₄R protein levels during gestation in fetal lung, which was also evident in gene expression microarray data. HTR4 mRNA expression, assessed by Q-PCR, was