Genetic and epigenetic mechanisms in aldosterone production and hypertension
Recent studies have shown that non-coding RNAs (miRNAs and long non-coding RNAs) have significant impact on mammalian regulatory mechanisms, and our work shows this to be true of aldosterone production, which is a key determinant of systemic blood pressure and a factor in hypertension and other cardiovascular complications. We have identified a miRNA cluster that appears to regulate the production of aldosterone in the adrenal cortex and its action in the kidney, creating a negative feedback loop between the tissues. In this project, we will study this miRNA cluster and its role in the physiology and pathophysiology of aldosterone production and action. From this project, we hope to identify new targets for the diagnosis / treatment of aldosterone excess, endocrine hypertension and its cardiovascular complications.
- Circulating levels of the miRNAs in the cluster will be measured in available, well-phenotyped subjects with hypertension using in-house miRNA profiling techniques which have been used successfully in other studies (ENS@T-HT). Genotype-phenotype correlations (e.g. miRNA levels, aldosterone and blood pressure) will be carried out using statistical packages.
- Deep sequencing analysis of the chromosomal loci encoding the miRNA cluster will be carried out to ascertain if there is a genetic alteration that may affect the expression of the miRNAs and nearby functional genes. The effects of mutations will be tested using in-house reporter gene and expression systems.
- Tissue localisation and quantification of the miRNA and its target gene(s) will be analysed using immunohistochemistry and in situ hybridisation, e.g. in the adrenal gland.
- Manipulations of the concentrations of the miRNAs in the cluster and their effect on target gene expression, identified using bioinformatics, and aldosterone production will be carried out using RT-PCR and ELISA/mass spectrometry in adrenal cell lines following transient transfection with relevant pre-mirs and antagomirs.
Secondments will be with Professor Maria-Christina Zennaro in Paris to perform multiplex immunohistochemistry / in situ hybridisation, with Attoquant in Austria to develop a new LC-MS/MS-based high-throughput/high accuracy system for multiplex quantification of miRNAs and with Bioscientifica in UK, to gain experience in scientific dissemination including publishing and conference management focused on the field of endocrinology.