Western diet induces renal artery endothelial stiffening that is dependent on the epithelial Na + channel

• Published in: American journal of physiology. Renal physiology 2020-05, Vol.318 (5), p.F1220-F1228
• Main Authors: Xiong, Yuxin, Aroor, Annayya R, Ramirez-Perez, Francisco I, Jia, Guanghong, Habibi, Javad, Manrique-Acevedo, Camila, Lastra, Guido, Chen, Donqqing, DeMarco, Vincent G, Martinez-Lemus, Luis A, Hill, Michael A, Jaisser, Frederic, Sowers, James R, Whaley-Connell, Adam
• Format: Article
• Language: English
• Subjects: Animals; Aorta; Aorta - metabolism; Aorta - pathology; Aorta - physiopathology; Atomic force microscopy; Bioavailability; Blood flow; Blood pressure; Body fat; Cell activation; Clonal deletion; Diet; Diet, Western - adverse effects; Elasticity; Endothelial cells; Endothelium; Epithelial Sodium Channels - deficiency; Epithelial Sodium Channels - genetics; Epithelial Sodium Channels - metabolism; Female; Fibrosis; Fructose; Inflammation; Kidneys; Mice, Inbred C57BL; Mice, Knockout; Nitric oxide; Nitric Oxide - metabolism; Nitric Oxide Synthase Type III - metabolism; Oxidants; Oxidative Stress; Renal artery; Renal Artery - pathology; Renal Artery - physiopathology; Signal Transduction; Sucrose; Ultrasound; Vascular Diseases - genetics; Vascular Diseases - metabolism; Vascular Diseases - pathology; Vascular Diseases - physiopathology; Vascular Remodeling; Vascular Stiffness; Veins & arteries
• ISSN: 1931-857X; 1522-1466
• DOI: 10.1152/ajprenal.00517.2019

Consumption of a Western diet (WD) induces central aortic stiffening that contributes to the transmittance of pulsatile blood flow to end organs, including the kidney. Our recent work supports that endothelial epithelial Na channel (EnNaC) expression and activation enhances aortic endothelial cell stiffening through reductions in endothelial nitric oxide (NO) synthase (eNOS) and bioavailable NO that result in inflammatory and oxidant responses and perivascular fibrosis. However, the role that EnNaC activation has on endothelial responses in the renal circulation remains unknown. We hypothesized that cell-specific deletion of the α-subunit of EnNaC would prevent WD-induced central aortic stiffness and protect the kidney from endothelial dysfunction and vascular stiffening. Twenty-eight-week-old female αEnNaC knockout and wild-type mice were fed either mouse chow or WD containing excess fat (46%), sucrose, and fructose (17.5% each). WD feeding increased fat mass, indexes of vascular stiffening in the aorta and renal artery (in vivo pulse wave velocity and ultrasound), and renal endothelial cell stiffening (ex vivo atomic force microscopy). WD further impaired aortic endothelium-dependent relaxation and renal artery compliance (pressure myography) without changes in blood pressure. WD-induced renal arterial stiffening occurred in parallel to attenuated eNOS activation, increased oxidative stress, and aortic and renal perivascular fibrosis. αEnNaC deletion prevented these abnormalities and support a novel mechanism by which WD contributes to renal arterial stiffening that is endothelium and Na channel dependent. These results demonstrate that cell-specific EnNaC is important in propagating pulsatility into the renal circulation, generating oxidant stress, reduced bioavailable NO, and renal vessel wall fibrosis and stiffening.