Chronic renal failure alters endothelial function in cerebral circulation in mice

Area of Science:

• Nephrology
• Vascular Biology
• Neuroscience

Background:

• Chronic renal failure (CRF) is associated with cardiovascular complications.
• Endothelial dysfunction plays a key role in the pathogenesis of vascular disease in CRF.
• Cerebral arterioles are critical for brain blood flow regulation.

Purpose of the Study:

• To investigate the impact of early-stage CRF on cerebral arteriolar structure, composition, and endothelial function in mice.
• To determine the expression of key proteins involved in nitric oxide (NO) production and vascular inflammation.
• To assess plasma levels of L-arginine and asymmetric dimethylarginine (ADMA) in CRF.

Main Methods:

• Utilized a murine model of CRF (C57BL/6J and apolipoprotein E knockout mice).
• Assessed cerebral arteriolar structure, composition, and endothelium-dependent/independent relaxation.
• Quantified expression of endothelial nitric oxide synthase (eNOS), phosphorylated eNOS, caveolin-1, vascular inflammation markers (Rock-1, Rock-2, VCAM-1), and PPARγ.
• Measured plasma L-arginine and ADMA concentrations.

Main Results:

• Endothelium-dependent relaxation was impaired in CRF, while endothelium-independent relaxation remained unaffected.
• CRF did not alter cerebral arteriolar structure or composition.
• PPARγ expression was significantly reduced, and inactive eNOS (p-eNOS T495) was increased in CRF mice.
• Plasma ADMA levels were elevated, and L-arginine levels were decreased in CRF mice.

Conclusions:

• Early-stage CRF impairs endothelial function in cerebral arterioles.
• These impairments may stem from decreased NO production, influenced by altered eNOS regulation and increased ADMA.
• Reduced PPARγ expression might contribute to vascular dysfunction in CRF.