microRNA expression profile in Smooth Muscle Cells isolated from thoracic aortic aneurysm samples.

PURPOSE: Thoracic aortic aneurysm (TAA) is a cardiovascular disease characterized by increased aortic diameter, treated with surgery and endovascular therapy in order to avoid aortic dissection or rupture. The mechanism of TAA formation has not been thoroughly studied and many factors have been proposed to drive its progression; however strong focus is attributed to modification of smooth muscle cells (SMCs). Latest research indicates, that microRNAs (miRNAs) may play a significant role in TAA development - these are multifunctional molecules consisting of 19-24 nucleotides involved in regulation of the gene expression level related to many biological processes, i.e. cardiovascular disease pathophysiology, immunity or inflammation.

MATERIALS AND

METHODS

Primary SMCs were isolated from aortic scraps of TAA patients and age- and sex-matched healthy controls. Purity of isolated SMCs was determined by flow cytometry using specific markers: α-SMA, CALP, MHC and VIM. Real-time polymerase chain reaction (RT-PCR) was conducted for miRNA analysis.

RESULTS

We established an isolation protocol and investigated the miRNA expression level in SMCs isolated from aneurysmal and non-aneurysmal aortic samples. We identified that let-7 g (0.71-fold, p = 0.01), miR-130a (0.40-fold, p = 0.04), and miR-221 (0.49-fold, p = 0.05) significantly differed between TAA patients and healthy controls.

CONCLUSIONS

Further studies are required to improve our understanding of the pathophysiology underlying TAA, which may aid the development of novel, targeted therapies. The pivotal role of miRNAs in the cardiovascular system provides a new perspective on the pathophysiology of thoracic aortic aneurysms.