Nitric Oxide in the Regulation of Mitochondrial Biogenesis

Author(s):  
Clara De Palma ◽  
Emilio Clementi
2013 ◽  
Vol 304 (12) ◽  
pp. H1624-H1633 ◽  
Author(s):  
Matthew W. Miller ◽  
Leslie A. Knaub ◽  
Luis F. Olivera-Fragoso ◽  
Amy C. Keller ◽  
Vivek Balasubramaniam ◽  
...  

Cardiovascular disease risk factors, such as diabetes, hypertension, dyslipidemia, obesity, and physical inactivity, are all correlated with impaired endothelial nitric oxide synthase (eNOS) function and decreased nitric oxide (NO) production. NO-mediated regulation of mitochondrial biogenesis has been established in many tissues, yet the role of eNOS in vascular mitochondrial biogenesis and dynamics is unclear. We hypothesized that genetic eNOS deletion and 3-day nitric oxide synthase (NOS) inhibition in rodents would result in impaired mitochondrial biogenesis and defunct fission/fusion and autophagy profiles within the aorta. We observed a significant, eNOS expression-dependent decrease in mitochondrial electron transport chain (ETC) protein subunits from complexes I, II, III, and V in eNOS heterozygotes and eNOS null mice compared with age-matched controls. In response to NOS inhibition with NG-nitro-l-arginine methyl ester (l-NAME) treatment in Sprague Dawley rats, significant decreases were observed in ETC protein subunits from complexes I, III, and IV as well as voltage-dependent anion channel 1. Decreased protein content of upstream regulators of mitochondrial biogenesis, cAMP response element-binding protein and peroxisome proliferator-activated receptor-γ coactivator-1α, were observed in response to 3-day l-NAME treatment. Both genetic eNOS deletion and NOS inhibition resulted in decreased manganese superoxide dismutase protein. l-NAME treatment resulted in significant changes to mitochondrial dynamic protein profiles with decreased fusion, increased fission, and minimally perturbed autophagy. In addition, l-NAME treatment blocked mitochondrial adaptation to an exercise intervention in the aorta. These results suggest that eNOS/NO play a role in basal and adaptive mitochondrial biogenesis in the vasculature and regulation of mitochondrial turnover.


2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Shasha Xing ◽  
Xiaoyan Yang ◽  
Wenjing Li ◽  
Fang Bian ◽  
Dan Wu ◽  
...  

Salidroside (SAL) is an active component ofRhodiola roseawith documented antioxidative properties. The purpose of this study is to explore the mechanism of the protective effect of SAL on hydrogen peroxide- (H2O2-) induced endothelial dysfunction. Pretreatment of the human umbilical vein endothelial cells (HUVECs) with SAL significantly reduced the cytotoxicity brought by H2O2. Functional studies on the rat aortas found that SAL rescued the endothelium-dependent relaxation and reduced superoxide anion (O2∙-) production induced by H2O2. Meanwhile, SAL pretreatment inhibited H2O2-induced nitric oxide (NO) production. The underlying mechanisms involve the inhibition of H2O2-induced activation of endothelial nitric oxide synthase (eNOS), adenosine monophosphate-activated protein kinase (AMPK), and Akt, as well as the redox sensitive transcription factor, NF-kappa B (NF-κB). SAL also increased mitochondrial mass and upregulated the mitochondrial biogenesis factors, peroxisome proliferator-activated receptor gamma-coactivator-1alpha (PGC-1α), and mitochondrial transcription factor A (TFAM) in the endothelial cells. H2O2-induced mitochondrial dysfunction, as demonstrated by reduced mitochondrial membrane potential (Δψm) and ATP production, was rescued by SAL pretreatment. Taken together, these findings implicate that SAL could protect endothelium against H2O2-induced injury via promoting mitochondrial biogenesis and function, thus preventing the overactivation of oxidative stress-related downstream signaling pathways.


2007 ◽  
Vol 102 (1) ◽  
pp. 314-320 ◽  
Author(s):  
G. D. Wadley ◽  
G. K. McConell

The purpose of this study was to determine whether nitric oxide synthase (NOS) inhibition decreased basal and exercise-induced skeletal muscle mitochondrial biogenesis. Male Sprague-Dawley rats were assigned to one of four treatment groups: NOS inhibitor NG-nitro-l-arginine methyl ester (l-NAME, ingested for 2 days in drinking water, 1 mg/ml) followed by acute exercise, no l-NAME ingestion and acute exercise, rest plus l-NAME, and rest without l-NAME. The exercised rats ran on a treadmill for 53 ± 2 min and were then killed 4 h later. NOS inhibition significantly ( P < 0.05; main effect) decreased basal peroxisome proliferator-activated receptor-γ coactivator 1β (PGC-1β) mRNA levels and tended ( P = 0.08) to decrease mtTFA mRNA levels in the soleus, but not the extensor digitorum longus (EDL) muscle. This coincided with significantly reduced basal levels of cytochrome c oxidase (COX) I and COX IV mRNA, COX IV protein and COX enzyme activity following NOS inhibition in the soleus, but not the EDL muscle. NOS inhibition had no effect on citrate synthase or β-hydroxyacyl CoA dehydrogenase activity, or cytochrome c protein abundance in the soleus or EDL. NOS inhibition did not reduce the exercise-induced increase in peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α) mRNA in the soleus or EDL. In conclusion, inhibition of NOS appears to decrease some aspects of the mitochondrial respiratory chain in the soleus under basal conditions, but does not attenuate exercise-induced mitochondrial biogenesis in the soleus or in the EDL.


2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Anthony Cyr ◽  
Lauran Chambers ◽  
Paul K. Waltz ◽  
Sean P. Whelan ◽  
Lauryn Kohut ◽  
...  

Background. Organ injury and dysfunction in sepsis accounts for significant morbidity and mortality. Adaptive cellular responses in the setting of sepsis prevent injury and allow for organ recovery. We and others have shown that part of the adaptive response includes regulation of cellular respiration and maintenance of a healthy mitochondrial population. Herein, we hypothesized that endotoxin-induced changes in hepatocyte mitochondrial respiration and homeostasis are regulated by an inducible nitric oxide synthase/nitric oxide (iNOS/NO)-mitochondrial reactive oxygen species (mtROS) signaling axis, involving activation of the NRF2 signaling pathway. Methods. Wild-type (C57Bl/6) or iNos-/- male mice were subjected to intraperitoneal lipopolysaccharide (LPS) injections to simulate endotoxemia. Individual mice were randomized to treatment with NO-releasing agent DPTA-NONOate, mtROS scavenger MitoTEMPO, or vehicle controls. Other mice were treated with scramble or Nrf2-specific siRNA via tail vein injection. Primary murine hepatocytes were utilized for in vitro studies with or without LPS stimulation. Oxygen consumption rates were measured to establish mitochondrial respiratory parameters. Western blotting, confocal microscopy with immunocytochemistry, and rtPCR were performed for analysis of iNOS as well as markers of both autophagy and mitochondrial biogenesis. Results. LPS treatment inhibited aerobic respiration in vitro in wild-type but not iNos-/- cells. Experimental endotoxemia in vivo or in vitro induced iNOS protein and mtROS production. However, induction of mtROS was dependent on iNOS expression. Furthermore, LPS-induced hepatic autophagy/mitophagy and mitochondrial biogenesis were significantly attenuated in iNos-/- mice or cells with NO or mtROS scavenging. These responses were rescued in iNos-/- mice via delivery of NO both in vivo and in vitro. Conclusions. These data suggest that regulation of mitochondrial quality control following hepatocyte LPS exposure is dependent at least in part on a NO-mtROS signaling network. Further investigation to identify specific agents that modulate this process may facilitate the prevention of organ injury in sepsis.


Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Paul Huang ◽  
Sylvia Lee-Huang

Introduction: In addition to its roles as a vascular signaling molecule, nitric oxide (NO) plays roles in metabolism. Mice deficient in eNOS are overweight and develop insulin resistance. It is not known whether the metabolic effects are due to primary roles of NO, or to increased visceral adiposity, leading to secondary metabolic changes. Hypothesis: We hypothesized that NO plays distinct and separable primary roles in white and brown adipogenesis, which underlie the effects on adiposity, energy metabolism, and expression of thermogenic genes. Methods: We exposed wild-type and mice carrying specific gain of function and loss of function eNOS mutations to cold at 4C for 48 hours and assessed expression of thermogenic gene programs in white and brown adipose tissue. To study cell autonomous effects, we differentiated adipocyte precursors from brown and white fat in the presence of NOS inhibitors and NO donors, as well as with siRNA to knockdown eNOS expression. Results: Cold exposure resulted in upregulation of the thermogenic gene program in brown adipose tissue. Animals carrying a gain of function mutation in eNOS showed increased UCP1 expression even without cold exposure. Induction of thermogenic genes was more pronounced in the animals with gain of function eNOS mutation. Differentiation of adipocyte precursors showed effects of eNOS on adipogenesis. Cells treated with the pharmacologic blockade (L-NAME and L-NA) as well as genetic knockdown (siRNA) showed dose-dependent inhibition of adipocyte differentiation. MitoTracker Red CMXRos staining showed that treatment with the NO donor SNAP increases mitochondrial biogenesis, while L-NAME decreases mitochondrial biogenesis. Conclusions: We show that eNOS-derived NO plays distinct and separable roles in white and brown adipogenesis. In brown adipocytes, eNOS regulates the expression of the thermogenic gene program, with upregulation of expression even without cold exposure, and greater increase in response to cold. In white adipocytes, eNOS-derived NO is required for adipocyte differentiation and mitochondrial biogenesis.


Sign in / Sign up

Export Citation Format

Share Document