Angiotensin II (AngII) induces the development of vascular
hypertrophy and
hypertension. We have shown previously that overexpression of class III deacetylase
SIRT1 inhibits AngII-induced
hypertrophy in vascular smooth muscle cells (VSMCs). However, the direct role of
SIRT1 in VSMCs in response to AngII infusion in vivo remains unclear. Here, we found that the expression and activity of
SIRT1 in mouse aortas was decreased significantly by AngII infusion. VSMC-specific
SIRT1 transgene (SV-Tg) prevented the increase in systolic blood pressure (SBP) caused by AngII infusion without affecting heart function in mice.
SIRT1 overexpression alleviated
vascular remodeling in mouse thoracic and renal aortas induced by AngII infusion, and significantly inhibited
reactive oxygen species (ROS) generation, vascular
inflammation, and
collagen synthesis in arterial walls. Reduced expression of
transforming growth factor-β 1 (TGF-β1) was also observed in the aortas of AngII-infused SV-Tg mice. Moreover,
SIRT1 overexpression decreased AngII-increased binding of nuclear factor-κB on its specific binding sites on TGF-β1 promoter. Taken together, these data demonstrate that
SIRT1 overexpression in VSMCs reduces SBP and inhibits AngII-induced
vascular remodeling in mice. The inhibition of
vascular remodeling contributes, at least in part, to the
antihypertensive effect of
SIRT1.
KEY MESSAGE:
SIRT1 is reduced in aortas of AngII-infused hypertensive mice.
SIRT1 VSMC transgene alleviates AngII-increased systolic blood pressure.
SIRT1 VSMC transgene attenuates AngII-induced
vascular remodeling. VSMC
SIRT1 overexpression inhibits remodeling-related pathological changes. VSMC
SIRT1 overexpression reduces AngII-induced TGF-β1 expression.