Recent Advances in Hypertension: Epigenetic Mechanism Involved in Development of Salt-Sensitive Hypertension

This review highlights recent insights into the epigenetic mechanism of salt-sensitive hypertension from the fetus to the elderly population, mainly focusing on the DNA methylation and histone modification-mediated regulation of hypertension-associated genes. Maternal malnutrition during pregnancy induces upregulation of AT1a (angiotensin receptor 1a) by aberrant DNA methylation, and increased AT1A activity in the hypothalamus develops prenatally programmed salt-sensitive hypertension through renal sympathetic overactivity. In addition, maternal lipopolysaccharide exposure during pregnancy induces upregulation of the Rac1 gene through histone modification by H3K9me2 across generations, resulting in salt-induced activation of the Rac1-MR (mineralocorticoid receptor) pathway in the kidney and the development of salt-sensitive hypertension in F4 and F5 offspring. In mice, aberrant DNA methylation of the Klotho gene, which regulates aging-associated hypertension, decreases the circulating soluble Klotho levels, leading to activation of the vascular Wnt5a-RhoA pathway and vasoconstriction and development of salt-sensitive hypertension because of decreased renal blood flow. A detailed understanding of the environmentally-induced epigenetic modulations related to salt-induced hypertension could be promising for developing preventive and therapeutic approaches to hypertension.