Endocrine Abstracts

Angiotensin II (AngII) mainly acts through type 1 angiotensin II receptor (AT1R) to promote a broad variety of biological effects. The vascular smooth muscle cells are one of the main target of AngII and its stimulation activates numerous signaling pathways which could result in gene expression changes in these cells. We carried out Affymetrix GeneChip experiments to analyze the effects of AngII stimulation on gene expression. More than 200 genes were upregulated in response to AngII stimulation of primary rat vascular smooth muscle cells in our experimental setup. We have selected several genes (i.e. Lmcd1, HbEGF, DUSP5, DUSP6, and DUSP10) to further investigate the kinetics of the gene-expression changes, and the possible signal transduction processes which lead to the altered expression changes after AngII stimulation. The results of the quantitative PCR measurements confirmed the AngII-induced upregulation of the investigated genes. The maximal induction of the most genes appeared two hours after the AngII stimulation. Our data show that the upregulated genes can be stimulated through several signal transduction pathways. We also examined the role of epidermal growth factor receptor (EGFR) transactivation in the upregulation of the investigated genes. According to our data the EGF receptor transactivation is not critical in response to AngII stimulation since knock-down of EGF receptor did not alter the AngII induced gene expression changes. Our pharmacological approach revealed that dasatinib, which is a potent inhibitor of ABL and Src family soluble tyrosine kinases, can significantly inhibit several gene expression changes. Interestingly, when we applied ABL kinase inhibitors, which have less potency toward Src tyrosine kinases such as imatinib or nilotinib did not evoke similar effects as dasatinib. Our data can help to understand the details of AngII-induced long term effects and the pathophysiology of AT1R, moreover it can help to develop potential interventions in symptoms when this receptor over functions such as vascular remodeling or atherosclerosis. This work was supported by the National Research, Development and Innovation Fund (NKFI K116954 and NVKP_16-1-2016-0039).