Cardiomyocyte-restricted restoration of nitric oxide synthase 3 attenuates left ventricular remodeling after chronic pressure overload.
Although nitric oxide synthase (NOS)3 is implicated as an important modulator of left ventricular (LV) remodeling, its role in the cardiac response to chronic pressure overload is controversial. We examined whether selective restoration of NOS3 to the hearts of NOS3-deficient mice would modulate the LV remodeling response to transverse aortic constriction (TAC). LV structure and function were compared at baseline and after TAC in NOS3-deficient (NOS3(-/-)) mice and NOS3(-/-) mice carrying a transgene directing NOS3 expression specifically in cardiomyocytes (NOS3(-/-TG) mice). At baseline, echocardiographic assessment of LV dimensions and function, invasive hemodynamic measurements, LV mass, and myocyte width did not differ between the two genotypes. Four weeks after TAC, echocardiographic and hemodynamic indexes of LV systolic function indicated that contractile performance was better preserved in NOS3(-/-TG) mice than in NOS3(-/-) mice. Echocardiographic LV wall thickness and cardiomyocyte width were greater in NOS3(-/-) mice than in NOS3(-/-TG) mice. TAC-induced cardiac fibrosis did not differ between these genotypes. TAC increased cardiac superoxide generation in NOS3(-/-TG) but not NOS3(-/-) mice. The ratio of NOS3 dimers to monomers did not differ before and after TAC in NOS3(-/-TG) mice. Restoration of NOS3 to the heart of NOS3-deficient mice attenuates LV hypertrophy and dysfunction after TAC, suggesting that NOS3 protects against the adverse LV remodeling induced by prolonged pressure overload.
Buys
Emmanuel S
ES
Cardiac Ultrasound Laboratory, 55 Fruit Street, Boston, MA 02115-2696, USA.
Raher
Michael J
MJ
Blake
Sarah L
SL
Neilan
Tomas G
TG
Graveline
Amanda R
AR
Passeri
Jonathan J
JJ
Llano
Miguel
M
Perez-Sanz
Teresa M
TM
Ichinose
Fumito
F
Janssens
Stefan
S
Zapol
Warren M
WM
Picard
Michael H
MH
Bloch
Kenneth D
KD
Scherrer-Crosbie
Marielle
M
D000818:Animals; D002478:Cells, Cultured; D006973:Hypertension / Q000503:physiopathology*; D017379:Hypertrophy, Left Ventricular / Q000503:physiopathology*; D051379:Mice; D008822:Mice, Transgenic; D032383:Myocytes, Cardiac / Q000201:enzymology*; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology*; D020257:Ventricular Remodeling / Q000502:physiology*
D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; C496315:Nos3 protein, mouse