In vivo klotho gene delivery protects against endothelial dysfunction in multiple risk factor syndrome

The klotho gene, originally identified by insertional mutagenesis in mice, suppresses multiple aging phenotypes (e.g., arteriosclerosis, pulmonary emphysema, osteoporosis, infertility, and short life span). We have previously shown that mice heterozygous for a defect in the klotho gene upon parabiosis with wild-type mice show improved endothelial function, suggesting that the klotho gene product protects against endothelial dysfunction. In the present study, using the Otsuka Long-Evans Tokushima Fatty (OLETF) rat which demonstrates multiple atherogenic risk factors (e.g., hypertension, obesity, severe hyperglycemia, and hypertriglyceridemia) and is thus considered an experimental animal model of atherosclerotic disease, we show that adenovirus-mediated klotho gene delivery can (1) ameliorate vascular endothelial dysfunction, (2) increase nitric oxide production, (3) reduce elevated blood pressure, and (4) prevent medial hypertrophy and perivascular fibrosis. Based on these findings, klotho gene delivery improves endothelial dysfunction through a pathway involving nitric oxide, and is involved in modulating vascular function (e.g., hypertension and vascular remodeling). Our findings establish the basis for the therapeutic potential of klotho gene delivery in atherosclerotic disease.