NOS1 induces NADPH oxidases and impairs contraction kinetics in aged murine ventricular myocytes

Abstract

Nitric oxide (NO) modulates calcium transients and contraction of cardiomyocytes. However, it is largely unknown whether NO contributes also to alterations in the contractile function of cardiomyocytes during aging. Therefore, we analyzed the putative role of nitric oxide synthases and NO for the age-related alterations of cardiomyocyte contraction. We used C57BL/6 mice, nitric oxide synthase 1 (NOS1)-deficient mice (NOS1(-/-)) and mice with cardiomyocyte-specific NOS1-overexpression to analyze contractions, calcium transients (Indo-1 fluorescence), acto-myosin ATPase activity (malachite green assay), NADPH oxidase activity (lucigenin chemiluminescence) of isolated ventricular myocytes and cardiac gene expression (Western blots, qPCR). In C57BL/6 mice, cardiac expression of NOS1 was upregulated by aging. Since we found a negative regulation of NOS1 expression by cAMP in isolated cardiomyocytes, we suggest that reduced efficacy of β-adrenergic signaling that is evident in aged hearts promotes upregulation of NOS1. Shortening and relengthening of cardiomyocytes from aged C57BL/6 mice were decelerated, but were normalized by pharmacological inhibition of NOS1/NO. Cardiomyocytes from NOS1(-/-) mice displayed no age-related changes in contraction, calcium transients or acto-myosin ATPase activity. Aging increased cardiac expression of NADPH oxidase subunits NOX2 and NOX4 in C57BL/6 mice, but not in NOS1(-/-) mice. Similarly, cardiac expression of NOX2 and NOX4 was upregulated in a murine model with cardiomyocyte-specific overexpression of NOS1. We conclude that age-dependently upregulated NOS1, putatively via reduced efficacy of β-adrenergic signaling, induces NADPH oxidases. By increasing nitrosative and oxidative stress, both enzyme systems act synergistically to decelerate contraction of aged cardiomyocytes.

NOX Inhibition Improves β-Adrenergic Stimulated Contractility and Intracellular Calcium Handling in the Aged Rat Heart

“…This increased activity in NOX activity in the aged heart has been proposed to depend on nitric oxide 1 (NOS1) [31] and on the renin-angiotensin system [8]. …”

Comprehensive Profiles of mRNAs and miRNAs Reveal Molecular Characteristics of Multiple Organ Physiologies and Development in Pigs

“…Of them, 37 miRNA–mRNA pairs showed significant negative expression correlations ( r < −0.5) through all three skeletal muscle development stages ( Table 5 ). Many mRNA genes have been reported as regulators of either muscle differentiation or development, including MyoD1 (Blum et al, 2012), CSRP2 (Herrmann et al, 2006), MBNL1 (Chen et al, 2016), FHOD1 (Staus et al, 2011), MET (Park et al, 2015), SOD1 (Sakellariou et al, 2018), RCAN1 (Emrani et al, 2015), SGCA (Fougerousse et al, 1998), SRF (Ding et al, 2017), MEF2A (Yuan et al, 2014), MTM1 (Bachmann et al, 2017), LBX1 (Chao et al, 2011), MEF2D (Runfola et al, 2015), IGFBP5 (Zhang et al, 2017), PDGFA (Tallquist et al, 2000), AMOT (Wang et al, 2018a), PDPK1 (Mora et al, 2003), SIRT2 (Arora and Dey, 2014), SIX4 (Chakroun et al, 2015), NOS1 (Villmow et al, 2015), MYL1 (Burguiere et al, 2011), ACTA1 (Hu et al, 2015), PROX1 (Kivela et al, 2016), and QKI (Wu et al, 2017). These interaction pairs included 7 known and 27 novel miRNAs, of which the miRNAs ssc-miR-744 (Yang et al, 2015), ssc-miR-497 (Sato et al, 2014), ssc-miR-338 (Mcdaneld et al, 2009), ssc-miR-423-3p (Siengdee et al, 2015), and ssc-miR-133a-3p (Wang et al, 2018c) were reported to have important roles in myogenesis.…”

Characterization and comparative transcriptomic analysis of skeletal muscle in female Pekin duck and Hanzhong Ma duck during different growth stages using RNA-seq

“…In previous studies, NOS1 was expressed in a subpopulation of atrial cardiomyocytes including myoendocrine cells and affected contraction of isolated myocytes. Moreover, in sarcoglycanopathies nNOS is a modulating factor in the course of muscular dystrophy ( Miethke et al, 2003 ; Angelini et al, 2014 ; Villmow et al, 2015 ).…”